An LDAP URL without a host name such as "ldap://" or without a base DN
such as "ldap://localhost" would cause a crash when reading pg_hba.conf.
If no binddn is configured, an error message might end up trying to print a
null pointer, which could crash on some platforms.
Author: Thomas Munro <thomas.munro@enterprisedb.com>
Reviewed-by: Michael Paquier <michael.paquier@gmail.com>
The point of having separate ResourceOwnerEnlargeFoo and
ResourceOwnerRememberFoo functions is so that resource allocation
can happen in between. Doing it in some other order is just wrong.
OpenTemporaryFile() did open(), enlarge, remember, which would leak the
open file if the enlarge step ran out of memory. Because fd.c has its own
layer of resource-remembering, the consequences look like they'd be limited
to an intratransaction FD leak, but it's still not good.
IncrBufferRefCount() did enlarge, remember, incr-refcount, which would blow
up if the incr-refcount step ever failed. It was safe enough when written,
but since the introduction of PrivateRefCountHash, I think the assumption
that no error could happen there is pretty shaky.
The odds of real problems from either bug are probably small, but still,
back-patch to supported branches.
Thomas Munro and Tom Lane, per a comment from Andres Freund
isdigit(), isspace(), etc are likely to give surprising results if passed a
signed char. We should always cast the argument to unsigned char to avoid
that. Error in commit 63d6b97fd, found by buildfarm member gaur.
Back-patch to 9.3, like that commit.
json{b}_populate_recordset() used the tuple descriptor created from the
query-level AS clause without worrying about whether it matched the actual
input record type. If it didn't, that would usually result in a crash,
though disclosure of server memory contents seems possible as well, for a
skilled attacker capable of issuing crafted SQL commands. Instead, use
the query-supplied descriptor only when there is no input tuple to look at,
and otherwise get a tuple descriptor based on the input tuple's own type
marking. The core code will detect any type mismatch in the latter case.
Michael Paquier and Tom Lane, per a report from David Rowley.
Back-patch to 9.3 where this functionality was introduced.
Security: CVE-2017-15098
The update path of an INSERT ... ON CONFLICT DO UPDATE requires SELECT
permission on the columns of the arbiter index, but it failed to check
for that in the case of an arbiter specified by constraint name.
In addition, for a table with row level security enabled, it failed to
check updated rows against the table's SELECT policies when the update
path was taken (regardless of how the arbiter index was specified).
Backpatch to 9.5 where ON CONFLICT DO UPDATE and RLS were introduced.
Security: CVE-2017-15099
Makefile.global assigns this prerequisite to every target named "check",
but similar targets must mention it explicitly. Affected targets
failed, tested $PATH binaries, or tested a stale temporary installation.
The src/test/modules examples worked properly when called as "make -C
src/test/modules/$FOO check", but "make -j" allowed the test to start
before the temporary installation was in place. Back-patch to 9.5,
where commit dcae5facca introduced the
shared temp-install.
If a process is extending a table concurrently with some BRIN
summarization process, it is possible for the latter to miss pages added
by the former because the number of pages is computed ahead of time.
Fix by determining a fresh relation size after inserting the placeholder
tuple: any process that further extends the table concurrently will
update the placeholder tuple, while previous pages will be processed by
the heap scan.
Reported-by: Tomas Vondra
Reviewed-by: Tom Lane
Author: Álvaro Herrera
Discussion: https://postgr.es/m/083d996a-4a8a-0e13-800a-851dd09ad8cc@2ndquadrant.com
Backpatch-to: 9.5
In some cases the BRIN code releases lock on an index page, and later
re-acquires lock and tries to check that the tuple it was working on is
still there. That check was a couple bricks shy of a load. It didn't
consider that the page might have turned into a "revmap" page. (The
samepage code path doesn't call brin_getinsertbuffer(), so it isn't
protected by the checks for revmap status there.) It also didn't check
whether the tuple offset was now off the end of the linepointer array.
Since commit 24992c6db the latter case is pretty common, but at least
in principle it could have occurred before that. The net result is
that concurrent updates of a BRIN index could fail with errors like
"invalid index offnum" or "inconsistent range map".
Per report from Tomas Vondra. Back-patch to 9.5, since this code is
substantially the same in all versions containing BRIN.
Discussion: https://postgr.es/m/10d2b9f9-f427-03b8-8ad9-6af4ecacbee9@2ndquadrant.com
It turns out we misdiagnosed what the real problem was. Revert the
previous changes, because they may have worse consequences going
forward. A better fix is forthcoming.
The simplistic test case is kept, though disabled.
Discussion: https://postgr.es/m/20171102112019.33wb7g5wp4zpjelu@alap3.anarazel.de
A candidate path needs to be canonicalized before being checked against
the mappings, because the mappings are also canonicalized. This is
especially relevant on Windows
Reported-by: nb <nbedxp@gmail.com>
Author: Michael Paquier <michael.paquier@gmail.com>
Reviewed-by: Ashutosh Sharma <ashu.coek88@gmail.com>
Without this fix, dropping a role can sometimes result in parallel
query failures in sessions that have used "SET ROLE" to assume the
dropped role, even if that setting isn't active any more.
Report by Pavan Deolasee. Patch by Amit Kapila, reviewed by me.
Discussion: http://postgr.es/m/CABOikdOomRcZsLsLK+Z+qENM1zxyaWnAvFh3MJZzZnnKiF+REg@mail.gmail.com
Commit d5b760ecb wasn't quite right, on second thought: if the
caller didn't ask for column names then it would happily emit
more Vars than if the caller did ask for column names. This
is surely not a good idea. Advance the aliasp_item whether or
not we're preparing a colnames list.
expandRTE() supposed that an RTE_SUBQUERY subquery must have exactly
as many non-junk tlist items as the RTE has column aliases for it.
This was true at the time the code was written, and is still true so
far as parse analysis is concerned --- but when the function is used
during planning, the subquery might have appeared through insertion
of a view that now has more columns than it did when the outer query
was parsed. This results in a core dump if, for instance, we have
to expand a whole-row Var that references the subquery.
To avoid crashing, we can either stop expanding the RTE when we run
out of aliases, or invent new aliases for the added columns. While
the latter might be more useful, the former is consistent with what
expandRTE() does for composite-returning functions in the RTE_FUNCTION
case, so it seems like we'd better do it that way.
Per bug #14876 from Samuel Horwitz. This has been busted since commit
ff1ea2173 allowed views to acquire more columns, so back-patch to all
supported branches.
Discussion: https://postgr.es/m/20171026184035.1471.82810@wrigleys.postgresql.org
On closer investigation, commits f3ea3e3e8 et al were a few bricks
shy of a load. What we need is not so much to lock down the result
type of a FieldSelect, as to lock down the existence of the column
it's trying to extract. Otherwise, we can break it by dropping that
column. The dependency on the result type is then held indirectly
through the column, and doesn't need to be recorded explicitly.
Out of paranoia, I left in the code to record a dependency on the
result type, but it's used only if we can't identify the pg_class OID
for the column. That shouldn't ever happen right now, AFAICS, but
it seems possible that in future the input node could be marked as
being of type RECORD rather than some specific composite type.
Likewise for FieldStore.
Like the previous patch, back-patch to all supported branches.
Discussion: https://postgr.es/m/22571.1509064146@sss.pgh.pa.us
If we try to run a parallel plan in serial mode because, for example,
it's going to be scanned via a cursor, but for some reason we're
already in parallel mode (for example because an outer query is
running in parallel), we'd incorrectly try to launch workers.
Fix by adding a flag to the EState, so that we can be certain that
ExecutePlan() and ExecGather()/ExecGatherMerge() will have the same
idea about whether we are executing serially or in parallel.
Report and fix by Amit Kapila with help from Kuntal Ghosh. A few
tweaks by me.
Discussion: http://postgr.es/m/CAA4eK1+_BuZrmVCeua5Eqnm4Co9DAXdM5HPAOE2J19ePbR912Q@mail.gmail.com
Previously, we skipped using search_indexed_tlist_for_sortgroupref()
if the tlist expression being sought in the child plan node was merely
a Var. This is purely an optimization, based on the theory that
search_indexed_tlist_for_var() is faster, and one copy of a Var should
be as good as another. However, the GROUPING SETS patch broke the
latter assumption: grouping columns containing the "same" Var can
sometimes have different outputs, as shown in the test case added here.
So do it the hard way whenever a ressortgroupref marking exists.
(If this seems like a bottleneck, we could imagine building a tlist index
data structure for ressortgroupref values, as we do for Vars. But I'll
let that idea go until there's some evidence it's worthwhile.)
Back-patch to 9.6. The problem also exists in 9.5 where GROUPING SETS
came in, but this patch is insufficient to resolve the problem in 9.5:
there is some obscure dependency on the upper-planner-pathification
work that happened in 9.6. Given that this is such a weird corner case,
and no end users have complained about it, it doesn't seem worth the work
to develop a fix for 9.5.
Patch by me, per a report from Heikki Linnakangas. (This does not fix
Heikki's original complaint, just the follow-on one.)
Discussion: https://postgr.es/m/aefc657e-edb2-64d5-6df1-a0828f6e9104@iki.fi
There have been numerous buildfarm failures but the diagnostic is
currently silent about the reason for failure to open the file. Let's
see if we can get to the bottom of it.
Backpatch to all live branches.
Some people like to run libpq-using applications in environments where
there's no home directory. We've broken that scenario before (cf commits
5b4067798 and bd58d9d88), and commit ba005f193 broke it again, by making
it a hard error if we fail to get the home directory name while looking
for ~/.pgpass. The previous precedent is that if we can't get the home
directory name, we should just silently act as though the file we hoped
to find there doesn't exist. Rearrange the new code to honor that.
Looking around, the service-file code added by commit 41a4e4595 had the
same disease. Apparently, that escaped notice because it only runs when
a service name has been specified, which I guess the people who use this
scenario don't do. Nonetheless, it's wrong too, so fix that case as well.
Add a comment about this policy to pqGetHomeDirectory, in the probably
vain hope of forestalling the same error in future. And upgrade the
rather miserable commenting in parseServiceInfo, too.
In passing, also back off parseServiceInfo's assumption that only ENOENT
is an ignorable error from stat() when checking a service file. We would
need to ignore at least ENOTDIR as well (cf 5b4067798), and seeing that
the far-better-tested code for ~/.pgpass treats all stat() failures alike,
I think this code ought to as well.
Per bug #14872 from Dan Watson. Back-patch the .pgpass change to v10
where ba005f193 came in. The service-file bugs are far older, so
back-patch the other changes to all supported branches.
Discussion: https://postgr.es/m/20171025200457.1471.34504@wrigleys.postgresql.org
json_build_object and json_build_array and the jsonb equivalents did not
correctly process explicit VARIADIC arguments. They are modified to use
the new extract_variadic_args() utility function which abstracts away
the details of the call method.
Michael Paquier, reviewed by Tom Lane and Dmitry Dolgov.
Backpatch to 9.5 for the jsonb fixes and 9.4 for the json fixes, as
that's where they originated.
This is epecially useful in the case or "VARIADIC ANY" functions. The
caller can get the artguments and types regardless of whether or not and
explicit VARIADIC array argument has been used. The function also
provides an option to convert arguments on type "unknown" to to "text".
Michael Paquier and me, reviewed by Tom Lane.
Backpatch to 9.4 in order to support the following json bug fix.
DST law changes in Fiji, Namibia, Northern Cyprus, Sudan, Tonga,
and Turks & Caicos Islands. Historical corrections for Alaska, Apia,
Burma, Calcutta, Detroit, Ireland, Namibia, and Pago Pago.
This is a trivial update containing only cosmetic changes. The point
is just to get back to being synced with an official release of tzcode,
rather than some ad-hoc point in their commit history, which is where
commit 47f849a3c left it.
find_expr_references() neglected to record a dependency on the result type
of a FieldSelect node, allowing a DROP TYPE to break a view or rule that
contains such an expression. I think we'd omitted this case intentionally,
reasoning that there would always be a related dependency ensuring that the
DROP would cascade to the view. But at least with nested field selection
expressions, that's not true, as shown in bug #14867 from Mansur Galiev.
Add the dependency, and for good measure a dependency on the node's exposed
collation.
Likewise add a dependency on the result type of a FieldStore. I think here
the reasoning was that it'd only appear within an assignment to a field,
and the dependency on the field's column would be enough ... but having
seen this example, I think that's wrong for nested-composites cases.
Looking at nearby code, I notice we're not recording a dependency on the
exposed collation of CoerceViaIO, which seems inconsistent with our choices
for related node types. Maybe that's OK but I'm feeling suspicious of this
code today, so let's add that; it certainly can't hurt.
This patch does not do anything to protect already-existing views, only
views created after it's installed. But seeing that the issue has been
there a very long time and nobody noticed till now, that's probably good
enough.
Back-patch to all supported branches.
Discussion: https://postgr.es/m/20171023150118.1477.19174@wrigleys.postgresql.org
Like the similar logic for arrays and records, it's necessary to examine
the range's subtype to decide whether the range type can support hashing.
We can omit checking the subtype for btree-defined operations, though,
since range subtypes are required to have those operations. (Possibly
that simplification for btree cases led us to overlook that it does
not apply for hash cases.)
This is only an issue if the subtype lacks hash support, which is not
true of any built-in range type, but it's easy to demonstrate a problem
with a range type over, eg, money: you can get a "could not identify
a hash function" failure when the planner is misled into thinking that
hash join or aggregation would work.
This was born broken, so back-patch to all supported branches.
This back-patches the v10-cycle commit 1e5a5d03d into 9.3 - 9.6.
I had noticed at the time that that was fixing a bug, namely that
next_token() might advance *lineptr past the line-terminating '\0',
but given the lack of field complaints I too easily convinced myself
that the problem was only latent. It's not, because tokenize_file()
decides whether there's more on the line using "strlen(lineptr)".
The bug is indeed latent on a newline-terminated line, because then
the newline-stripping bit in tokenize_file() means we'll have two
or more consecutive '\0's in the buffer, masking the fact that we
accidentally advanced over the first one. But the last line in
the file might not be null-terminated, allowing the loop to see
and process garbage, as reported by Mark Jones in bug #14859.
The bug doesn't exist in <= 9.2; there next_token() is reading directly
from a file, and termination of the outer loop relies on an feof() test
not a buffer pointer check. Probably commit 7f49a67f9 can be blamed
for this bug, but I didn't track it down exactly.
Commit 1e5a5d03d does a bit more than the minimum needed to fix the
bug, but I felt the rest of it was good cleanup, so applying it all.
Discussion: https://postgr.es/m/20171017141814.8203.27280@wrigleys.postgresql.org
If we merge the transition calculations for two different aggregates,
it's reasonable to assume that the transition function should not care
which of those Aggref structs it gets from AggGetAggref(). It is not
reasonable to make the same assumption about an aggregate final function,
however. Commit 804163bc2 broke this, as it will pass whichever Aggref
was first associated with the transition state in both cases.
This doesn't create an observable bug so far as the core system is
concerned, because the only existing uses of AggGetAggref() are in
ordered-set aggregates that happen to not pay attention to anything
but the input properties of the Aggref; and besides that, we disabled
sharing of transition calculations for OSAs yesterday. Nonetheless,
if some third-party code were using AggGetAggref() in a normal aggregate,
they would be entitled to call this a bug. Hence, back-patch the fix
to 9.6 where the problem was introduced.
In passing, improve some of the comments about transition state sharing.
Discussion: https://postgr.es/m/CAB4ELO5RZhOamuT9Xsf72ozbenDLLXZKSk07FiSVsuJNZB861A@mail.gmail.com
This ought to work, but the built-in OSAs are not capable of coping,
because their final-functions destructively modify their transition
state (specifically, the contained tuplesort object). That was fine
when those functions were written, but commit 804163bc2 moved the
goalposts without telling orderedsetaggs.c.
We should fix the built-in OSAs to support this, but it will take
a little work, especially if we don't want to sacrifice performance
in the normal non-shared-state case. Given that it took a year after
9.6 release for anyone to notice this bug, we should not prioritize
sharable-state over nonsharable-state performance. And a proper fix
is likely to be more complicated than we'd want to back-patch, too.
Therefore, let's just put in this stop-gap patch to prevent nodeAgg.c
from choosing to use shared state for OSAs. We can revert it in HEAD
when we get a better fix.
Report from Lukas Eder, diagnosis by me, patch by David Rowley.
Back-patch to 9.6 where the problem was introduced.
Discussion: https://postgr.es/m/CAB4ELO5RZhOamuT9Xsf72ozbenDLLXZKSk07FiSVsuJNZB861A@mail.gmail.com
The previous coding in ProcessInterrupts() could lead to
idle_in_transaction_session_timeout being ignored, when
statement_timeout occurred earlier.
The problem was that ProcessInterrupts() would return before
processing the transaction timeout if QueryCancelPending was set while
QueryCancelHoldoffCount != 0 - which is the case when reading new
commands from the client. Ergo when the idle transaction timeout would
hit.
Fix that by removing the early return. Alternatively the transaction
timeout code could have been moved up, but that early return seems
like an issue that could hit other cases too.
Author: Lukas Fittl
Bug: #14821
Discussion:
https://www.postgresql.org/message-id/20170921010956.17345.61461%40wrigleys.postgresql.orghttps://www.postgresql.org/message-id/CAP53PkxQnv3OWJpyNPGJYT62uY=n1=2CF_Lpc6gVOFnc0-gazw@mail.gmail.com
Backpatch: 9.6-, where idle_in_transaction_session_timeout was introduced.
The GRANT reference page, which lists the default privileges for new
objects, failed to mention that USAGE is granted by default for data
types and domains. As a lesser sin, it also did not specify anything
about the initial privileges for sequences, FDWs, foreign servers,
or large objects. Fix that, and add a comment to acldefault() in the
probably vain hope of getting people to maintain this list in future.
Noted by Laurenz Albe, though I editorialized on the wording a bit.
Back-patch to all supported branches, since they all have this behavior.
Discussion: https://postgr.es/m/1507620895.4152.1.camel@cybertec.at
Up to now async.c has used TransactionIdIsInProgress() to detect whether
a notify message's source transaction is still running. However, that
function has a quick-exit path that reports that XIDs before RecentXmin
are no longer running. If a listening backend is doing nothing but
listening, and not running any queries, there is nothing that will advance
its value of RecentXmin. Once 2 billion transactions elapse, the
RecentXmin check causes active transactions to be reported as not running.
If they aren't committed yet according to CLOG, async.c decides they
aborted and discards their messages. The timing for that is a bit tight
but it can happen when multiple backends are sending notifies concurrently.
The net symptom therefore is that a sufficiently-long-surviving
listen-only backend starts to miss some fraction of NOTIFY traffic,
but only under heavy load.
The only function that updates RecentXmin is GetSnapshotData().
A brute-force fix would therefore be to take a snapshot before
processing incoming notify messages. But that would add cycles,
as well as contention for the ProcArrayLock. We can be smarter:
having taken the snapshot, let's use that to check for running
XIDs, and not call TransactionIdIsInProgress() at all. In this
way we reduce the number of ProcArrayLock acquisitions from one
per message to one per notify interrupt; that's the same under
light load but should be a benefit under heavy load. Light testing
says that this change is a wash performance-wise for normal loads.
I looked around for other callers of TransactionIdIsInProgress()
that might be at similar risk, and didn't find any; all of them
are inside transactions that presumably have already taken a
snapshot.
Problem report and diagnosis by Marko Tiikkaja, patch by me.
Back-patch to all supported branches, since it's been like this
since 9.0.
Discussion: https://postgr.es/m/20170926182935.14128.65278@wrigleys.postgresql.org
copy_file() reads and writes data 64KB at a time (with default BLCKSZ),
and historically has issued a pg_flush_data request after each write.
This turns out to interact really badly with macOS's new APFS file
system: a large file copy takes over 100X longer than it ought to on
APFS, as reported by Brent Dearth. While that's arguably a macOS bug,
it's not clear whether Apple will do anything about it in the near
future, and in any case experimentation suggests that issuing flushes
a bit less often can be helpful on other platforms too.
Hence, rearrange the logic in copy_file() so that flush requests are
issued once per N writes rather than every time through the loop.
I set the FLUSH_DISTANCE to 32MB on macOS (any less than that still
results in a noticeable speed degradation on APFS), but 1MB elsewhere.
In limited testing on Linux and FreeBSD, this seems slightly faster
than the previous code, and certainly no worse. It helps noticeably
on macOS even with the older HFS filesystem.
A simpler change would have been to just increase the size of the
copy buffer without changing the loop logic, but that seems likely
to trash the processor cache without really helping much.
Back-patch to 9.6 where we introduced msync() as an implementation
option for pg_flush_data(). The problem seems specific to APFS's
mmap/msync support, so I don't think we need to go further back.
Discussion: https://postgr.es/m/CADkxhTNv-j2jw2g8H57deMeAbfRgYBoLmVuXkC=YCFBXRuCOww@mail.gmail.com
The logical decoding functions do BeginInternalSubTransaction and
RollbackAndReleaseCurrentSubTransaction to clean up after themselves.
It turns out that AtEOSubXact_SPI has an unrecognized assumption that
we always need to cancel the active SPI operation in the SPI context
that surrounds the subtransaction (if there is one). That's true
when the RollbackAndReleaseCurrentSubTransaction call is coming from
the SPI-using function itself, but not when it's happening inside
some unrelated function invoked by a SPI query. In practice the
affected callers are the various PLs.
To fix, record the current subtransaction ID when we begin a SPI
operation, and clean up only if that ID is the subtransaction being
canceled.
Also, remove AtEOSubXact_SPI's assertion that it must have cleaned
up the surrounding SPI context's active tuptable. That's proven
wrong by the same test case.
Also clarify (or, if you prefer, reinterpret) the calling conventions
for _SPI_begin_call and _SPI_end_call. The memory context cleanup
in the latter means that these have always had the flavor of a matched
resource-management pair, but they weren't documented that way before.
Per report from Ben Chobot.
Back-patch to 9.4 where logical decoding came in. In principle,
the SPI changes should go all the way back, since the problem dates
back to commit 7ec1c5a86. But given the lack of field complaints
it seems few people are using internal subtransactions in this way.
So I don't feel a need to take any risks in 9.2/9.3.
Discussion: https://postgr.es/m/73FBA179-C68C-4540-9473-71E865408B15@silentmedia.com
Sloppy loop coding in set_status_by_pages() resulted in fetching one array
element more than it should from the subxids[] array. The odds of this
resulting in SIGSEGV are pretty small, but we've certainly seen that happen
with similar mistakes elsewhere. While at it, we can get rid of an extra
TransactionIdToPage() calculation per loop.
Per report from David Binderman. Back-patch to all supported branches,
since this code is quite old.
Discussion: https://postgr.es/m/HE1PR0802MB2331CBA919CBFFF0C465EB429C710@HE1PR0802MB2331.eurprd08.prod.outlook.com
When some tuple versions in an update chain are frozen due to them being
older than freeze_min_age, the xmax/xmin trail can become broken. This
breaks HOT (and probably other things). A subsequent VACUUM can break
things in more serious ways, such as leaving orphan heap-only tuples
whose root HOT redirect items were removed. This can be seen because
index creation (or REINDEX) complain like
ERROR: XX000: failed to find parent tuple for heap-only tuple at (0,7) in table "t"
Because of relfrozenxid contraints, we cannot avoid the freezing of the
early tuples, so we must cope with the results: whenever we see an Xmin
of FrozenTransactionId, consider it a match for whatever the previous
Xmax value was.
This problem seems to have appeared in 9.3 with multixact changes,
though strictly speaking it seems unrelated.
Since 9.4 we have commit 37484ad2a "Change the way we mark tuples as
frozen", so the fix is simple: just compare the raw Xmin (still stored
in the tuple header, since freezing merely set an infomask bit) to the
Xmax. But in 9.3 we rewrite the Xmin value to FrozenTransactionId, so
the original value is lost and we have nothing to compare the Xmax with.
To cope with that case we need to compare the Xmin with FrozenXid,
assume it's a match, and hope for the best. Sadly, since you can
pg_upgrade a 9.3 instance containing half-frozen pages to newer
releases, we need to keep the old check in newer versions too, which
seems a bit brittle; I hope we can somehow get rid of that.
I didn't optimize the new function for performance. The new coding is
probably a bit slower than before, since there is a function call rather
than a straight comparison, but I'd rather have it work correctly than
be fast but wrong.
This is a followup after 20b6552242 fixed a few related problems.
Apparently, in 9.6 and up there are more ways to get into trouble, but
in 9.3 - 9.5 I cannot reproduce a problem anymore with this patch, so
there must be a separate bug.
Reported-by: Peter Geoghegan
Diagnosed-by: Peter Geoghegan, Michael Paquier, Daniel Wood,
Yi Wen Wong, Álvaro
Discussion: https://postgr.es/m/CAH2-Wznm4rCrhFAiwKPWTpEw2bXDtgROZK7jWWGucXeH3D1fmA@mail.gmail.com
1. Since commit b1a9bad9e7 we had pstrdup() inside a
spinlock-protected critical section; reported by Andreas Seltenreich.
Turn those into strlcpy() to stack-allocated variables instead.
Backpatch to 9.6.
2. Since commit 9ed551e0a4 we had a pfree() uselessly inside a
spinlock-protected critical section. Tom Lane noticed in code review.
Move down. Backpatch to 9.6.
3. Since commit 64233902d2 we had GetCurrentTimestamp() (a kernel
call) inside a spinlock-protected critical section. Tom Lane noticed in
code review. Move it up. Backpatch to 9.2.
4. Since commit 1bb2558046 we did elog(PANIC) while holding spinlock.
Tom Lane noticed in code review. Release spinlock before dying.
Backpatch to 9.2.
Discussion: https://postgr.es/m/87h8vhtgj2.fsf@ansel.ydns.eu
Buildfarm members skink and sungazer have both recently failed this
test, with symptoms indicating that the default 3-second timeout
isn't quite enough for those very slow systems. There's no reason
to be miserly with this timeout, so boost it to 60 seconds.
Back-patch to all versions containing this test. That may be overkill,
because the failure has only been observed in the v10 branch, but
I don't feel like having to revisit this later.
Vacuum calls page-level HOT prune to remove dead HOT tuples before doing
liveness checks (HeapTupleSatisfiesVacuum) on the remaining tuples. But
concurrent transaction commit/abort may turn DEAD some of the HOT tuples
that survived the prune, before HeapTupleSatisfiesVacuum tests them.
This happens to activate the code that decides to freeze the tuple ...
which resuscitates it, duplicating data.
(This is especially bad if there's any unique constraints, because those
are now internally violated due to the duplicate entries, though you
won't know until you try to REINDEX or dump/restore the table.)
One possible fix would be to simply skip doing anything to the tuple,
and hope that the next HOT prune would remove it. But there is a
problem: if the tuple is older than freeze horizon, this would leave an
unfrozen XID behind, and if no HOT prune happens to clean it up before
the containing pg_clog segment is truncated away, it'd later cause an
error when the XID is looked up.
Fix the problem by having the tuple freezing routines cope with the
situation: don't freeze the tuple (and keep it dead). In the cases that
the XID is older than the freeze age, set the HEAP_XMAX_COMMITTED flag
so that there is no need to look up the XID in pg_clog later on.
An isolation test is included, authored by Michael Paquier, loosely
based on Daniel Wood's original reproducer. It only tests one
particular scenario, though, not all the possible ways for this problem
to surface; it be good to have a more reliable way to test this more
fully, but it'd require more work.
In message https://postgr.es/m/20170911140103.5akxptyrwgpc25bw@alvherre.pgsql
I outlined another test case (more closely matching Dan Wood's) that
exposed a few more ways for the problem to occur.
Backpatch all the way back to 9.3, where this problem was introduced by
multixact juggling. In branches 9.3 and 9.4, this includes a backpatch
of commit e5ff9fefcd50 (of 9.5 era), since the original is not
correctable without matching the coding pattern in 9.5 up.
Reported-by: Daniel Wood
Diagnosed-by: Daniel Wood
Reviewed-by: Yi Wen Wong, Michaël Paquier
Discussion: https://postgr.es/m/E5711E62-8FDF-4DCA-A888-C200BF6B5742@amazon.com
float8_numeric() and float4_numeric() failed to consider the possibility
that the input is an IEEE infinity. The results depended on the
platform-specific behavior of sprintf(): on most platforms you'd get
something like
ERROR: invalid input syntax for type numeric: "inf"
but at least on Windows it's possible for the conversion to succeed and
deliver a finite value (typically 1), due to a nonstandard output format
from sprintf and lack of syntax error checking in these functions.
Since our numeric type lacks the concept of infinity, a suitable conversion
is impossible; the best thing to do is throw an explicit error before
letting sprintf do its thing.
While at it, let's use snprintf not sprintf. Overrunning the buffer
should be impossible if sprintf does what it's supposed to, but this
is cheap insurance against a stack smash if it doesn't.
Problem reported by Taiki Kondo. Patch by me based on fix suggestion
from KaiGai Kohei. Back-patch to all supported branches.
Discussion: https://postgr.es/m/12A9442FBAE80D4E8953883E0B84E088C8C7A2@BPXM01GP.gisp.nec.co.jp
posix_fallocate() is not quite a drop-in replacement for fallocate(),
because it is defined to return the error code as its function result,
not in "errno". I (tgl) missed this because RHEL6's version seems
to set errno as well. That is not the case on more modern Linuxen,
though, as per buildfarm results.
Aside from fixing the return-convention confusion, remove the test
for ENOSYS; we expect that glibc will mask that for posix_fallocate,
though it does not for fallocate. Keep the test for EINTR, because
POSIX specifies that as a possible result, and buildfarm results
suggest that it can happen in practice.
Back-patch to 9.4, like the previous commit.
Thomas Munro
Discussion: https://postgr.es/m/1002664500.12301802.1471008223422.JavaMail.yahoo@mail.yahoo.com
On Linux, shared memory segments created with shm_open() are backed by
swap files created in tmpfs. If the swap file needs to be extended,
but there's no tmpfs space left, you get a very unfriendly SIGBUS trap.
To avoid this, force allocation of the full request size when we create
the segment. This adds a few cycles, but none that we wouldn't expend
later anyway, assuming the request isn't hugely bigger than the actual
need.
Make this code #ifdef __linux__, because (a) there's not currently a
reason to think the same problem exists on other platforms, and (b)
applying posix_fallocate() to an FD created by shm_open() isn't very
portable anyway.
Back-patch to 9.4 where the DSM code came in.
Thomas Munro, per a bug report from Amul Sul
Discussion: https://postgr.es/m/1002664500.12301802.1471008223422.JavaMail.yahoo@mail.yahoo.com
In two cases, we set a different umask for some piece of code and
restore it afterwards. But if the contained code errors out, the umask
is not restored. So add TRY/CATCH blocks to fix that.
This patch absorbs a few unreleased fixes in the IANA code.
It corresponds to commit 2d8b944c1cec0808ac4f7a9ee1a463c28f9cd00a
in https://github.com/eggert/tz. Non-cosmetic changes include:
TZDEFRULESTRING is updated to match current US DST practice,
rather than what it was over ten years ago. This only matters
for interpretation of POSIX-style zone names (e.g., "EST5EDT"),
and only if the timezone database doesn't include either an exact
match for the zone name or a "posixrules" entry. The latter
should not be true in any current Postgres installation, but
this could possibly matter when using --with-system-tzdata.
Get rid of a nonportable use of "++var" on a bool var.
This is part of a larger fix that eliminates some vestigial
support for consecutive leap seconds, and adds checks to
the "zic" compiler that the data files do not specify that.
Remove a couple of ancient compatibility hacks. The IANA
crew think these are obsolete, and I tend to agree. But
perhaps our buildfarm will think different.
Back-patch to all supported branches, in line with our policy
that all branches should be using current IANA code. Before v10,
this includes application of current pgindent rules, to avoid
whitespace problems in future back-patches.
Discussion: https://postgr.es/m/E1dsWhf-0000pT-F9@gemulon.postgresql.org
Previously, the code didn't think about this case and would just try to
analyze such a column twice. That would fail at the point of inserting
the second version of the pg_statistic row, with obscure error messsages
like "duplicate key value violates unique constraint" or "tuple already
updated by self", depending on context and PG version. We could allow
the case by ignoring duplicate column specifications, but it seems better
to reject it explicitly.
The bogus error messages seem like arguably a bug, so back-patch to
all supported versions.
Nathan Bossart, per a report from Michael Paquier, and whacked
around a bit by me.
Discussion: https://postgr.es/m/E061A8E3-5E3D-494D-94F0-E8A9B312BBFC@amazon.com
AfterTriggerEndQuery correctly notes that the query_stack could get
repalloc'd during a trigger firing, but it nonetheless passes the address
of a query_stack entry to afterTriggerInvokeEvents, so that if such a
repalloc occurs, afterTriggerInvokeEvents is already working with an
obsolete dangling pointer while it scans the rest of the events. Oops.
The only code at risk is its "delete_ok" cleanup code, so we can
prevent unsafe behavior by passing delete_ok = false instead of true.
However, that could have a significant performance penalty, because the
point of passing delete_ok = true is to not have to re-scan possibly
a large number of dead trigger events on the next time through the loop.
There's more than one way to skin that cat, though. What we can do is
delete all the "chunks" in the event list except the last one, since
we know all events in them must be dead. Deleting the chunks is work
we'd have had to do later in AfterTriggerEndQuery anyway, and it ends
up saving rescanning of just about the same events we'd have gotten
rid of with delete_ok = true.
In v10 and HEAD, we also have to be careful to mop up any per-table
after_trig_events pointers that would become dangling. This is slightly
annoying, but I don't think that normal use-cases will traverse this code
path often enough for it to be a performance problem.
It's pretty hard to hit this in practice because of the unlikelihood
of the query_stack getting resized at just the wrong time. Nonetheless,
it's definitely a live bug of ancient standing, so back-patch to all
supported branches.
Discussion: https://postgr.es/m/2891.1505419542@sss.pgh.pa.us
The order in which GRANTs are output is important as GRANTs which have
been GRANT'd by individuals via WITH GRANT OPTION GRANTs have to come
after the GRANT which included the WITH GRANT OPTION. This happens
naturally in the backend during normal operation as we only change
existing ACLs in-place, only add new ACLs to the end, and when removing
an ACL we remove any which depend on it also.
Also, adjust the comments in acl.h to make this clear.
Unfortunately, the updates to pg_dump to handle initial privileges
involved pulling apart ACLs and then combining them back together and
could end up putting them back together in an invalid order, leading to
dumps which wouldn't restore.
Fix this by adjusting the queries used by pg_dump to ensure that the
ACLs are rebuilt in the same order in which they were originally.
Back-patch to 9.6 where the changes for initial privileges were done.
When copying from an active database tree, it's possible for files to be
deleted after we see them in a readdir() scan but before we can open them.
(Once we've got a file open, we don't expect any further errors from it
getting unlinked, though.) Tweak RecursiveCopy so it can cope with this
case, so as to avoid irreproducible test failures.
Back-patch to 9.6 where this code was added. In v10 and HEAD, also
remove unused "use RecursiveCopy" in one recovery test script.
Michael Paquier and Tom Lane
Discussion: https://postgr.es/m/24621.1504924323@sss.pgh.pa.us
In commit 9d6b160d7, I tweaked pg_config.h.win32 to use
"#define HAVE_LONG_LONG_INT_64 1" rather than defining it as empty,
for consistency with what happens in an autoconf'd build.
But Solution.pm injects another definition of that macro into
ecpg_config.h, leading to justifiable (though harmless) compiler whining.
Make that one consistent too. Back-patch, like the previous patch.
Discussion: https://postgr.es/m/CAEepm=1dWsXROuSbRg8PbKLh0S=8Ou-V8sr05DxmJOF5chBxqQ@mail.gmail.com
Instead of using a cast to force the constant to be the right width,
assume we can plaster on an L, UL, LL, or ULL suffix as appropriate.
The old approach to this is very hoary, dating from before we were
willing to require compilers to have working int64 types.
This fix makes the PG_INT64_MIN, PG_INT64_MAX, and PG_UINT64_MAX
constants safe to use in preprocessor conditions, where a cast
doesn't work. Other symbolic constants that might be defined using
[U]INT64CONST are likewise safer than before.
Also fix the SIZE_MAX macro to be similarly safe, if we are forced
to provide a definition for that. The test added in commit 2e70d6b5e
happens to do what we want even with the hack "(size_t) -1" definition,
but we could easily get burnt on other tests in future.
Back-patch to all supported branches, like the previous commits.
Discussion: https://postgr.es/m/15883.1504278595@sss.pgh.pa.us
Pre-C99 platforms may lack <stdint.h> and thereby SIZE_MAX. We have
a couple of places using the hack "(size_t) -1" as a fallback, but
it wasn't universally available; which means the code added in commit
2e70d6b5e fails to compile everywhere. Move that hack to c.h so that
we can rely on having SIZE_MAX everywhere.
Per discussion, it'd be a good idea to make the macro's value safe
for use in #if-tests, but that will take a bit more work. This is
just a quick expedient to get the buildfarm green again.
Back-patch to all supported branches, like the previous commit.
Discussion: https://postgr.es/m/15883.1504278595@sss.pgh.pa.us
Adding more than 1 billion rows to a PGresult would overflow its ntups and
tupArrSize fields, leading to client crashes. It'd be desirable to use
wider fields on 64-bit machines, but because all of libpq's external APIs
use plain "int" for row counters, that's going to be hard to accomplish
without an ABI break. Given the lack of complaints so far, and the general
pain that would be involved in using such huge PGresults, let's settle for
just preventing the overflow and reporting a useful error message if it
does happen. Also, for a couple more lines of code we can increase the
threshold of trouble from INT_MAX/2 to INT_MAX rows.
To do that, refactor pqAddTuple() to allow returning an error message that
replaces the default assumption that it failed because of out-of-memory.
Along the way, fix PQsetvalue() so that it reports all failures via
pqInternalNotice(). It already did so in the case of bad field number,
but neglected to report anything for other error causes.
Because of the potential for crashes, this seems like a back-patchable
bug fix, despite the lack of field reports.
Michael Paquier, per a complaint from Igor Korot.
Discussion: https://postgr.es/m/CA+FnnTxyLWyjY1goewmJNxC==HQCCF4fKkoCTa9qR36oRAHDPw@mail.gmail.com
2cd7084524 / c6293249d change the way individual attributes in a
TupleDesc are stored / accessed. To reduce the effort of making
extensions compatible with postgresql 11, and to ease future
backpatching, backpatch introduction of TupleDescAttr() to all
releases. Do not backpatch change in storage, as that'd be a breaking
change for existing and working extensions.
Author: Andres Freund
Discussion: https://postgr.es/m/20170820181723.tdswdinzptbcwhrr@alap3.anarazel.de
Backpatch: 9.2-
Commit 3eb9a5e7c unintentionally introduced an ordering dependency
into restore_toc_entries_prefork(). The existing coding of
reduce_dependencies() contains a check to skip moving a TOC entry
to the ready_list if it wasn't initially in the pending_list.
This used to suffice to prevent reduce_dependencies() from trying to
move anything into the ready_list during restore_toc_entries_prefork(),
because the pending_list stayed empty throughout that phase; but it no
longer does. The problem doesn't manifest unless the TOC has been
reordered by SortTocFromFile, which is how I missed it in testing.
To fix, just add a test for ready_list == NULL, converting the call
with NULL from a poor man's sanity check into an explicit command
not to touch TOC items' list membership. Clarify some of the comments
around this; in particular, note the primary purpose of the check for
pending_list membership, which is to ensure that we can't try to restore
the same item twice, in case a TOC list forces it to be restored before
its dependency count goes to zero.
Per report from Fabrízio de Royes Mello. Back-patch to 9.3, like the
previous commit.
Discussion: https://postgr.es/m/CAFcNs+pjuv0JL_x4+=71TPUPjdLHOXA4YfT32myj_OrrZb4ohA@mail.gmail.com
It now emerges that we can only rely on Perl to tell us we must use
-D_USE_32BIT_TIME_T if it's Perl 5.13.4 or later. For older versions,
revert to our previous practice of assuming we need that symbol in
all 32-bit Windows builds. This is not ideal, but inquiring into
which compiler version Perl was built with seems far too fragile.
In any case, we had not previously had complaints about these old
Perl versions, so let's assume this is Good Enough. (It's still
better than the situation ante commit 5a5c2feca, in that at least
the effects are confined to PL/Perl rather than the whole PG build.)
Back-patch to all supported versions, like 5a5c2feca and predecessors.
Discussion: https://postgr.es/m/CANFyU97OVQ3+Mzfmt3MhuUm5NwPU=-FtbNH5Eb7nZL9ua8=rcA@mail.gmail.com
Although not confirmed and probably rare, if the newly allocated memory
is not already zero, this could possibly have caused some problems.
Also reorder the initializations slightly so they match the order of the
struct definition.
Author: Wong, Yi Wen <yiwong@amazon.com>
Reviewed-by: Masahiko Sawada <sawada.mshk@gmail.com>
This appears to have been an omission in the original commit
0d692a0dc9. All related information_schema views already include
foreign tables.
Reported-by: Nicolas Thauvin <nicolas.thauvin@dalibo.com>
Stress testing by Andreas Seltenreich disclosed longstanding problems that
occur if a FATAL exit (e.g. due to receipt of SIGTERM) occurs while we are
trying to execute a ROLLBACK of an already-failed transaction. In such a
case, xact.c is in TBLOCK_ABORT state, so that AbortOutOfAnyTransaction
would skip AbortTransaction and go straight to CleanupTransaction. This
led to an assert failure in an assert-enabled build (due to the ROLLBACK's
portal still having a cleanup hook) or without assertions, to a FATAL exit
complaining about "cannot drop active portal". The latter's not
disastrous, perhaps, but it's messy enough to want to improve it.
We don't really want to run all of AbortTransaction in this code path.
The minimum required to clean up the open portal safely is to do
AtAbort_Memory and AtAbort_Portals. It seems like a good idea to
do AtAbort_Memory unconditionally, to be entirely sure that we are
starting with a safe CurrentMemoryContext. That means that if the
main loop in AbortOutOfAnyTransaction does nothing, we need an extra
step at the bottom to restore CurrentMemoryContext = TopMemoryContext,
which I chose to do by invoking AtCleanup_Memory. This'll result in
calling AtCleanup_Memory twice in many of the paths through this function,
but that seems harmless and reasonably inexpensive.
The original motivation for the assertion in AtCleanup_Portals was that
we wanted to be sure that any user-defined code executed as a consequence
of the cleanup hook runs during AbortTransaction not CleanupTransaction.
That still seems like a valid concern, and now that we've seen one case
of the assertion firing --- which means that exactly that would have
happened in a production build --- let's replace the Assert with a runtime
check. If we see the cleanup hook still set, we'll emit a WARNING and
just drop the hook unexecuted.
This has been like this a long time, so back-patch to all supported
branches.
Discussion: https://postgr.es/m/877ey7bmun.fsf@ansel.ydns.eu
Commit 3c163a7fc's original choice to ignore all #define symbols whose
names begin with underscore turns out to be too simplistic. On Windows,
some Perl installations are built with -D_USE_32BIT_TIME_T, and we must
absorb that or we get the wrong result for sizeof(PerlInterpreter).
This effectively re-reverts commit ef58b87df, which injected that symbol
in a hacky way, making it apply to all of Postgres not just PL/Perl.
More significantly, it did so on *all* 32-bit Windows builds, even when
the Perl build to be used did not select this option; so that it fails
to work properly with some newer Perl builds.
By making this change, we would be introducing an ABI break in 32-bit
Windows builds; but fortunately we have not used type time_t in any
exported Postgres APIs in a long time. So it should be OK, both for
PL/Perl itself and for third-party extensions, if an extension library
is built with a different _USE_32BIT_TIME_T setting than the core code.
Patch by me, based on research by Ashutosh Sharma and Robert Haas.
Back-patch to all supported branches, as commit 3c163a7fc was.
Discussion: https://postgr.es/m/CANFyU97OVQ3+Mzfmt3MhuUm5NwPU=-FtbNH5Eb7nZL9ua8=rcA@mail.gmail.com
The sole useful effect of this function, to check that no catcache
entries have positive refcounts at transaction end, has really been
obsolete since we introduced ResourceOwners in PG 8.1. We reduced the
checks to assertions years ago, so that the function was a complete
no-op in production builds. There have been previous discussions about
removing it entirely, but consensus up to now was that it had some small
value as a cross-check for bugs in the ResourceOwner logic.
However, it now emerges that it's possible to trigger these assertions
if you hit an assert-enabled backend with SIGTERM during a call to
SearchCatCacheList, because that function temporarily increases the
refcounts of entries it's intending to add to a catcache list construct.
In a normal ERROR scenario, the extra refcounts are cleaned up by
SearchCatCacheList's PG_CATCH block; but in a FATAL exit we do a
transaction abort and exit without ever executing PG_CATCH handlers.
There's a case to be made that this is a generic hazard and we should
consider restructuring elog(FATAL) handling so that pending PG_CATCH
handlers do get run. That's pretty scary though: it could easily create
more problems than it solves. Preliminary stress testing by Andreas
Seltenreich suggests that there are not many live problems of this ilk,
so we rejected that idea.
There are more-localized ways to fix the problem; the most principled
one would be to use PG_ENSURE_ERROR_CLEANUP instead of plain PG_TRY.
But adding cycles to SearchCatCacheList isn't very appealing. We could
also weaken the assertions in AtEOXact_CatCache in some more or less
ad-hoc way, but that just makes its raison d'etre even less compelling.
In the end, the most reasonable solution seems to be to just remove
AtEOXact_CatCache altogether, on the grounds that it's not worth trying
to fix it. It hasn't found any bugs for us in many years.
Per report from Jeevan Chalke. Back-patch to all supported branches.
Discussion: https://postgr.es/m/CAM2+6=VEE30YtRQCZX7_sCFsEpoUkFBV1gZazL70fqLn8rcvBA@mail.gmail.com
find_composite_type_dependencies correctly found columns that are of
the specified type, and columns that are of arrays of that type, but
not columns that are domains or ranges over the given type, its array
type, etc. The most general way to handle this seems to be to assume
that any type that is directly dependent on the specified type can be
treated as a container type, and processed recursively (allowing us
to handle nested cases such as ranges over domains over arrays ...).
Since a type's array type already has such a dependency, we can drop
the existing special case for the array type.
The very similar logic in get_rels_with_domain was likewise a few
bricks shy of a load, as it supposed that a directly dependent type
could *only* be a sub-domain. This is already wrong for ranges over
domains, and it'll someday be wrong for arrays over domains.
Add test cases illustrating the problems, and back-patch to all
supported branches.
Discussion: https://postgr.es/m/15268.1502309024@sss.pgh.pa.us
Commit 1efc7e538 did a poor job of emulating existing logic for touching
Datums that might be expanded-object pointers. It didn't check for typlen
being -1 first, which meant it could crash on fixed-length pass-by-ref
values, and probably on cstring values as well. It also didn't use
DatumGetPointer before VARATT_IS_EXTERNAL_EXPANDED, which while currently
harmless is not according to documentation nor prevailing style.
I also think the lack of any explanation as to why datumSerialize makes
these particular nonobvious choices is pretty awful, so fix that.
Per report from Jarred Ward. Back-patch to 9.6 where this code came in.
Discussion: https://postgr.es/m/6F61E6D2-2F5E-4794-9479-A429BE1CEA4B@simple.com
lo_put() surely should require UPDATE permission, the same as lowrite(),
but it failed to check for that, as reported by Chapman Flack. Oversight
in commit c50b7c09d; backpatch to 9.4 where that was introduced.
Tom Lane and Michael Paquier
Security: CVE-2017-7548
Commit 3eefc51053 claimed to make
pg_user_mappings enforce the qualifications user_mapping_options had
been enforcing, but its removal of a longstanding restriction left them
distinct when the current user is the subject of a mapping yet has no
server privileges. user_mapping_options emits no rows for such a
mapping, but pg_user_mappings includes full umoptions. Change
pg_user_mappings to show null for umoptions. Back-patch to 9.2, like
the above commit.
Reviewed by Tom Lane. Reported by Jeff Janes.
Security: CVE-2017-7547
Some authentication methods allowed it, others did not. In the client-side,
libpq does not even try to authenticate with an empty password, which makes
using empty passwords hazardous: an administrator might think that an
account with an empty password cannot be used to log in, because psql
doesn't allow it, and not realize that a different client would in fact
allow it. To clear that confusion and to be be consistent, disallow empty
passwords in all authentication methods.
All the authentication methods that used plaintext authentication over the
wire, except for BSD authentication, already checked that the password
received from the user was not empty. To avoid forgetting it in the future
again, move the check to the recv_password_packet function. That only
forbids using an empty password with plaintext authentication, however.
MD5 and SCRAM need a different fix:
* In stable branches, check that the MD5 hash stored for the user does not
not correspond to an empty string. This adds some overhead to MD5
authentication, because the server needs to compute an extra MD5 hash, but
it is not noticeable in practice.
* In HEAD, modify CREATE and ALTER ROLE to clear the password if an empty
string, or a password hash that corresponds to an empty string, is
specified. The user-visible behavior is the same as in the stable branches,
the user cannot log in, but it seems better to stop the empty password from
entering the system in the first place. Secondly, it is fairly expensive to
check that a SCRAM hash doesn't correspond to an empty string, because
computing a SCRAM hash is much more expensive than an MD5 hash by design,
so better avoid doing that on every authentication.
We could clear the password on CREATE/ALTER ROLE also in stable branches,
but we would still need to check at authentication time, because even if we
prevent empty passwords from being stored in pg_authid, there might be
existing ones there already.
Reported by Jeroen van der Ham, Ben de Graaff and Jelte Fennema.
Security: CVE-2017-7546
The callers for GetOldestSafeDecodingTransactionId() all inverted the
argument for the argument introduced in 2bef06d516. Luckily this
appears to be inconsequential for the moment, as we wait for
concurrent in-progress transaction when assembling a
snapshot. Additionally this could only make a difference when adding a
second logical slot, because only a pre-existing slot could cause an
issue by lowering the returned xid dangerously much.
Reported-By: Antonin Houska
Discussion: https://postgr.es/m/32704.1496993134@localhost
Backport: 9.4-, where 2bef06d516 was backpatched to.
We don't actually support session tickets, since we do not create an SSL
session identifier. But it seems that OpenSSL will issue a session ticket
on-demand anyway, which will then fail when used. This results in
reconnection failures when using ticket-aware client-side SSL libraries
(such as the Npgsql .NET driver), as reported by Shay Rojansky.
To fix, just tell OpenSSL not to issue tickets. At some point in the
far future, we might consider enabling tickets instead. But the security
implications of that aren't entirely clear; and besides it would have
little benefit except for very short-lived database connections, which is
Something We're Bad At anyhow. It would take a lot of other work to get
to a point where that would really be an exciting thing to do.
While at it, also tell OpenSSL not to use a session cache. This doesn't
really do anything, since a backend would never populate the cache anyway,
but it might gain some micro-efficiencies and/or reduce security
exposures.
Patch by me, per discussion with Heikki Linnakangas and Shay Rojansky.
Back-patch to all supported versions.
Discussion: https://postgr.es/m/CADT4RqBU8N-csyZuzaook-c795dt22Zcwg1aHWB6tfVdAkodZA@mail.gmail.com
Because we push all ACL (i.e. GRANT/REVOKE) restore steps to the end,
materialized view refreshes were occurring while the permissions on
referenced objects were still at defaults. This led to failures if,
say, an MV owned by user A reads from a table owned by user B, even
if B had granted the necessary privileges to A. We've had multiple
complaints about that type of restore failure, most recently from
Jordan Gigov.
The ideal fix for this would be to start treating ACLs as dependency-
sortable objects, rather than hard-wiring anything about their dump order
(the existing approach is a messy kluge dating to commit dc0e76ca3).
But that's going to be a rather major change, and it certainly wouldn't
lead to a back-patchable fix. As a short-term solution, convert the
existing two-pass hack (ie, normal objects then ACLs) to a three-pass hack,
ie, normal objects then ACLs then matview refreshes. Because this happens
in RestoreArchive(), it will also fix the problem when restoring from an
existing archive-format dump.
(Note this means that if a matview refresh would have failed under the
permissions prevailing at dump time, it'll fail during restore as well.
We'll define that as user error rather than something we should try
to work around.)
To avoid performance loss in parallel restore, we need the matview
refreshes to still be parallelizable. Hence, clean things up enough
so that both ACLs and matviews are handled by the parallel restore
infrastructure, instead of reverting back to serial restore for ACLs.
There is still a final serial step, but it shouldn't normally have to
do anything; it's only there to try to recover if we get stuck due to
some problem like unresolved circular dependencies.
Patch by me, but it owes something to an earlier attempt by Kevin Grittner.
Back-patch to 9.3 where materialized views were introduced.
Discussion: https://postgr.es/m/28572.1500912583@sss.pgh.pa.us
Commit 4d57e83816 added support for getting I/O errors out of zlib,
but it introduced a portability problem for systems without zlib.
Repair by wrapping the zlib call inside #ifdef and restore the original
code in the other branch.
This serves to illustrate the inadequacy of the zlib abstraction in
pg_backup_archiver: there is no way to call gzerror() in that
abstraction. This means that the several places that call GZREAD and
GZWRITE are currently doing error reporting wrongly, but ENOTIME to get
it fixed before next week's release set.
Backpatch to 9.4, like the commit that introduced the problem.
Some error reports were reporting strerror(errno), which for some error
conditions coming from zlib are wrong, resulting in confusing reports
such as
pg_restore: [compress_io] could not read from input file: Success
which makes no sense. To correctly extract the error message we need to
use gzerror(), so let's do that.
This isn't as comprehensive or as neat as I would like, but at least it
should improve things in many common cases. The zlib abstraction in
compress_io does not seem to be applied consistently enough; we could
perhaps improve that, but it seems master-only material, not a bug fix
for back-patching.
This problem goes back all the way, but I decided to apply back to 9.4
only, because older branches don't contain commit 14ea89366 which this
change depends on.
Authors: Vladimir Kunschikov, Álvaro Herrera
Discussion: https://postgr.es/m/1498120508308.9826@infotecs.ru
init_htab(), with #define HASH_DEBUG, prints a bunch of hashtable
parameters. It used to also print nentries, but commit 44ca4022f changed
that to "hash_get_num_entries(hctl)", which is wrong (the parameter should
be "hashp").
Rather than correct the coding, though, let's just remove that field from
the printout. The table must be empty, since we just finished building
it, so expensively calculating the number of entries is rather pointless.
Moreover hash_get_num_entries makes assumptions (about not needing locks)
which we could do without in debugging code.
Noted by Choi Doo-Won in bug #14764. Back-patch to 9.6 where the
faulty code was introduced.
Discussion: https://postgr.es/m/20170802032353.8424.12274@wrigleys.postgresql.org
XLByteToSeg and XLByteToPrevSeg calculate only a segment number. The
definition of these macros were modified by commit
dfda6ebaec but the comment remain
unchanged.
Patch by Yugo Nagata. Back patched to 9.3 and beyond.
The comment for dumpACL() got neglected when initacls and initracls were
added and the discussion of what 'racls' is wasn't very clear either.
Per complaint from Tom.
Fix assorted places that had not bothered with the convention of
prefixing catalog and function names with "pg_catalog.". That
could possibly result in query failure when running with a nondefault
search_path. Also fix two places that weren't quoting OID literals.
I think the latter hasn't mattered much since about 7.3, but it's still
a bad idea to be doing it in 99 places and not in 2 others.
Also remove a useless EXISTS sub-select that someone had stuck into
describeOneTableDetails' queries for child tables. We just got the OID
out of pg_class, so I hardly see how checking that it exists in pg_class
was doing anything helpful.
In passing, try to improve the emitted formatting of a couple of
these queries, though I didn't work really hard on that. And merge
unnecessarily duplicative coding in some other places.
Much of this was new in HEAD, but some was quite old; back-patch
as appropriate.
If several sessions are concurrently locking a tuple update chain with
nonconflicting lock modes using an old snapshot, and they all succeed,
it may happen that some of them fail because of restarting the loop (due
to a concurrent Xmax change) and getting an error in the subsequent pass
while trying to obtain a tuple lock that they already have in some tuple
version.
This can only happen with very high concurrency (where a row is being
both updated and FK-checked by multiple transactions concurrently), but
it's been observed in the field and can have unpleasant consequences
such as an FK check failing to see a tuple that definitely exists:
ERROR: insert or update on table "child_table" violates foreign key constraint "fk_constraint_name"
DETAIL: Key (keyid)=(123456) is not present in table "parent_table".
(where the key is observably present in the table).
Discussion: https://postgr.es/m/20170714210011.r25mrff4nxjhmf3g@alvherre.pgsql
This module becomes much more useful if we allow it to be used as base
class for external projects. To achieve this, change the exported
get_new_node function into a class method instead, and use the standard
Perl idiom of accepting the class as first argument. This method works
as expected for subclasses. The standalone function is kept for
backwards compatibility, though it could be removed in pg11.
Author: Chap Flackman, based on an earlier patch from Craig Ringer
Discussion: https://postgr.es/m/CAMsr+YF8kO+4+K-_U4PtN==2FndJ+5Bn6A19XHhMiBykEwv0wA@mail.gmail.com
Trading a little too heavily on letting the code path be the same whether
we were creating shared data structures or only attaching to them,
InitPredicateLocks() inserted the "scratch" PredicateLockTargetHash entry
unconditionally. This is just wrong if we're in a postmaster child,
which would only reach this code in EXEC_BACKEND builds. Most of the
time, the hash_search(HASH_ENTER) call would simply report that the
entry already existed, causing no visible effect since the code did not
bother to check for that possibility. However, if this happened while
some other backend had transiently removed the "scratch" entry, then
that other backend's eventual RestoreScratchTarget would suffer an
assert failure; this appears to be the explanation for a recent failure
on buildfarm member culicidae. In non-assert builds, there would be
no visible consequences there either. But nonetheless this is a pretty
bad bug for EXEC_BACKEND builds, for two reasons:
1. Each new backend would perform the hash_search(HASH_ENTER) call
without holding any lock that would prevent concurrent access to the
PredicateLockTargetHash hash table. This creates a low but certainly
nonzero risk of corruption of that hash table.
2. In the event that the race condition occurred, by reinserting the
scratch entry too soon, we were defeating the entire purpose of the
scratch entry, namely to guarantee that transaction commit could move
hash table entries around with no risk of out-of-memory failure.
The odds of an actual OOM failure are quite low, but not zero, and if
it did happen it would again result in corruption of the hash table.
The user-visible symptoms of such corruption are a little hard to predict,
but would presumably amount to misbehavior of SERIALIZABLE transactions
that'd require a crash or postmaster restart to fix.
To fix, just skip the hash insertion if IsUnderPostmaster. I also
inserted a bunch of assertions that the expected things happen
depending on whether IsUnderPostmaster is true. That might be overkill,
since most comparable code in other functions isn't quite that paranoid,
but once burnt twice shy.
In passing, also move a couple of lines to places where they seemed
to make more sense.
Diagnosis of problem by Thomas Munro, patch by me. Back-patch to
all supported branches.
Discussion: https://postgr.es/m/10593.1500670709@sss.pgh.pa.us
If the user modifies a view that has CHECK OPTIONs and this gets
translated into a modification to an underlying relation which happens
to be a foreign table, the check options should be enforced. In the
normal code path, that was happening properly, but it was not working
properly for "direct" modification because the whole operation gets
pushed to the remote side in that case and we never have an option to
enforce the constraint against individual tuples. Fix by disabling
direct modification when there is a need to enforce CHECK OPTIONs.
Etsuro Fujita, reviewed by Kyotaro Horiguchi and by me.
Discussion: http://postgr.es/m/f8a48f54-6f02-9c8a-5250-9791603171ee@lab.ntt.co.jp
Various cases involving renaming of view columns are handled by having
make_viewdef pass down the view's current relation tupledesc to
get_query_def, which then takes care to use the column names from the
tupledesc for the output column names of the SELECT. For some reason
though, we'd missed teaching make_ruledef to do similarly when it is
printing an ON SELECT rule, even though this is exactly the same case.
The results from pg_get_ruledef would then be different and arguably wrong.
In particular, this breaks pre-v10 versions of pg_dump, which in some
situations would define views by means of emitting a CREATE RULE ... ON
SELECT command. Third-party tools might not be happy either.
In passing, clean up some crufty code in make_viewdef; we'd apparently
modernized the equivalent code in make_ruledef somewhere along the way,
and missed this copy.
Per report from Gilles Darold. Back-patch to all supported versions.
Discussion: https://postgr.es/m/ec05659a-40ff-4510-fc45-ca9d965d0838@dalibo.com
pg_dump with the --clean option failed to emit DROP EVENT TRIGGER
commands for event triggers. In a closely related oversight,
it also did not emit ALTER OWNER commands for event triggers.
Since only superusers can create event triggers, the latter oversight
is of little practical consequence ... but if we're going to record
an owner for event triggers, then surely pg_dump should preserve it.
Per complaint from Greg Atkins. Back-patch to 9.3 where event triggers
were introduced.
Discussion: https://postgr.es/m/20170722191142.yi4e7tzcg3iacclg@gmail.com
When incrementally updating a file larger than 2GB, the old code could
either fail outright (if the client asked the server for bytes beyond
the 2GB boundary) or fail to copy all the blocks that had actually
been modified (if the server reported a file size to the client in
excess of 2GB), resulting in data corruption. Generally, such files
won't occur anyway, but they might if using a non-default segment size
or if there the directory contains stray files unrelated to
PostgreSQL. Fix by a more prudent choice of data types.
Even with these improvements, this code still uses a mix of different
types (off_t, size_t, uint64, int64) to represent file sizes and
offsets, not all of which necessarily have the same width or
signedness, so further cleanup might be in order here. However, at
least now they all have the potential to be 64 bits wide on 64-bit
platforms.
Kuntal Ghosh and Michael Paquier, with a tweak by me.
Discussion: http://postgr.es/m/CAGz5QC+8gbkz=Brp0TgoKNqHWTzonbPtPex80U0O6Uh_bevbaA@mail.gmail.com
SLRU buffer lwlocks are allocated twice by oversight in commit
fe702a7b3f where that locks were moved to
separate tranche. The bug doesn't have user-visible effects except small
overspending of shared memory.
Backpatch to 9.6 where it was introduced.
Alexander Korotkov with small editorization by me.
Normally, a JoinExpr would have empty "quals" only if it came from CROSS
JOIN syntax. However, it's possible to get to this state by specifying
NATURAL JOIN between two tables with no common column names, and there
might be other ways too. The code previously printed no ON clause if
"quals" was empty; that's right for CROSS JOIN but syntactically invalid
if it's some type of outer join. Fix by printing ON TRUE in that case.
This got broken by commit 2ffa740be, which stopped using NATURAL JOIN
syntax in ruleutils output due to its brittleness in the face of
column renamings. Back-patch to 9.3 where that commit appeared.
Per report from Tushar Ahuja.
Discussion: https://postgr.es/m/98b283cd-6dda-5d3f-f8ac-87db8c76a3da@enterprisedb.com
It seems pretty confusing to have tests named both largeobject and
large_object. The latter is of very recent vintage (commit ff992c074),
so get rid of it in favor of merging into the former.
Also, enable the LO comment test that was added by commit 70ad7ed4e,
since the later commit added the then-missing pg_upgrade functionality.
The large_object.sql test case is almost completely redundant with that,
but not quite: it seems like creating a user-defined LO with an OID in
the system range might be an interesting case for pg_upgrade, so let's
keep it.
Like the earlier patch, back-patch to all supported branches.
Discussion: https://postgr.es/m/18665.1500306372@sss.pgh.pa.us
In the frontend Makefiles that pull in libpgfeutils, we'd generally
done it like this:
LDFLAGS += -L$(top_builddir)/src/fe_utils -lpgfeutils $(libpq_pgport)
That method is badly broken, as seen in bug #14742 from Chris Ruprecht.
The -L flag for src/fe_utils ends up being placed after whatever random
-L flags are in LDFLAGS already. That puts us at risk of pulling in
libpgfeutils.a from some previous installation rather than the freshly
built one in src/fe_utils. Also, the lack of an "override" is hazardous
if someone tries to specify some LDFLAGS on the make command line.
The correct way to do it is like this:
override LDFLAGS := -L$(top_builddir)/src/fe_utils -lpgfeutils $(libpq_pgport) $(LDFLAGS)
so that libpgfeutils, along with libpq, libpgport, and libpgcommon, are
guaranteed to be pulled in from the build tree and not from any referenced
system directory, because their -L flags will appear first.
In some places we'd been even lazier and done it like this:
LDFLAGS += -L$(top_builddir)/src/fe_utils -lpgfeutils -lpq
which is subtly wrong in an additional way: on platforms where we can't
restrict the symbols exported by libpq.so, it allows libpgfeutils to
latch onto libpgport and libpgcommon symbols from libpq.so, rather than
directly from those static libraries as intended. This carries hazards
like those explained in the comments for the libpq_pgport macro.
In addition to fixing the broken libpgfeutils usages, I tried to
standardize on using $(libpq_pgport) like so:
override LDFLAGS := $(libpq_pgport) $(LDFLAGS)
even where libpgfeutils is not in the picture. This makes no difference
right now but will hopefully discourage future mistakes of the same ilk.
And it's more like the way we handle CPPFLAGS in libpq-using Makefiles.
In passing, just for consistency, make pgbench include PTHREAD_LIBS the
same way everyplace else does, ie just after LIBS rather than in some
random place in the command line. This might have practical effect if
there are -L switches in that macro on some platform.
It looks to me like the MSVC build scripts are not affected by this
error, but someone more familiar with them than I might want to double
check.
Back-patch to 9.6 where libpgfeutils was introduced. In 9.6, the hazard
this error creates is that a reinstallation might link to the prior
installation's copy of libpgfeutils.a and thereby fail to absorb a
minor-version bug fix.
Discussion: https://postgr.es/m/20170714125106.9231.13772@wrigleys.postgresql.org
When writing a backup to stdout with pg_basebackup on Windows, put stdout
to binary mode. Any CR bytes in the output will otherwise be output
incorrectly as CR+LF.
In the passing, standardize on using "_setmode" instead of "setmode", for
the sake of consistency. They both do the same thing, but according to
MSDN documentation, setmode is deprecated.
Fixes bug #14634, reported by Henry Boehlert. Patch by Haribabu Kommi.
Backpatch to all supported versions.
Discussion: https://www.postgresql.org/message-id/20170428082818.24366.13134@wrigleys.postgresql.org
The grammar will only accept something syntactically similar to a function
call in a function-in-FROM expression. However, there are various ways
to input something that ruleutils.c won't deparse that way, potentially
leading to a view or rule that fails dump/reload. Fix by inserting a
dummy CAST around anything that isn't going to deparse as a function
(which is one of the ways to get something like that in there in the
first place).
In HEAD, also make use of the infrastructure added by this to avoid
emitting unnecessary parentheses in CREATE INDEX deparsing. I did
not change that in back branches, thinking that people might find it
to be unexpected/unnecessary behavioral change.
In HEAD, also fix incorrect logic for when to add extra parens to
partition key expressions. Somebody apparently thought they could
get away with simpler logic than pg_get_indexdef_worker has, but
they were wrong --- a counterexample is PARTITION BY LIST ((a[1])).
Ignoring the prettyprint flag for partition expressions isn't exactly
a nice solution anyway.
This has been broken all along, so back-patch to all supported branches.
Discussion: https://postgr.es/m/10477.1499970459@sss.pgh.pa.us
The race condition goes like this:
1. GetNewTransactionId advances nextXid e.g. from 100 to 101
2. GetOldestActiveTransactionId reads the new nextXid, 101
3. GetOldestActiveTransactionId loops through the proc array. There are no
active XIDs there, so it returns 101 as the oldest active XID.
4. GetNewTransactionid stores XID 100 to MyPgXact->xid
So, GetOldestActiveTransactionId returned XID 101, even though 100 only
just started and is surely still running.
This would be hard to hit in practice, and even harder to spot any ill
effect if it happens. GetOldestActiveTransactionId is only used when
creating a checkpoint in a master server, and the race condition can only
happen on an online checkpoint, as there are no backends running during a
shutdown checkpoint. The oldestActiveXid value of an online checkpoint is
only used when starting up a hot standby server, to determine the starting
point where pg_subtrans is initialized from. For the race condition to
happen, there must be no other XIDs in the proc array that would hold back
the oldest-active XID value, which means that the missed XID must be a top
transaction's XID. However, pg_subtrans is not used for top XIDs, so I
believe an off-by-one error is in fact inconsequential. Nevertheless, let's
fix it, as it's clearly wrong and the fix is simple.
This has been wrong ever since hot standby was introduced, so backport to
all supported versions.
Discussion: https://www.postgresql.org/message-id/e7258662-82b6-7a45-56d4-99b337a32bf7@iki.fi
Further investigation shows that ruleutils isn't quite up to speed either
for cases where we have a domain-over-array: it needs to be prepared to
look past a CoerceToDomain at the top level of field and element
assignments, else it decompiles them incorrectly. Potentially this would
result in failure to dump/reload a rule, if it looked like the one in the
new test case. (I also added a test for EXPLAIN; that output isn't broken,
but clearly we need more test coverage here.)
Like commit b1cb32fb6, this bug is reachable in cases we already support,
so back-patch all the way.
compute_tsvector_stats() detoasted and kept in memory every tsvector value
in the sample, but that can be a lot of memory. The original bug report
described a case using over 10 gigabytes, with statistics target of 10000
(the maximum).
To fix, allocate a separate copy of just the lexemes that we keep around,
and free the detoasted tsvector values as we go. This adds some palloc/pfree
overhead, when you have a lot of distinct lexemes in the sample, but it's
better than running out of memory.
Fixes bug #14654 reported by James C. Reviewed by Tom Lane. Backport to
all supported versions.
Discussion: https://www.postgresql.org/message-id/20170514200602.1451.46797@wrigleys.postgresql.org
If the number of tuples in the heap exceeds approximately INT_MAX/2,
this loop's calculation "2*i+1" could overflow, resulting in a crash.
Fix it by using unsigned int rather than int for the relevant local
variables; that shouldn't cost anything extra on any popular hardware.
Per bug #14722 from Sergey Koposov.
Original patch by Sergey Koposov, modified by me per a suggestion
from Heikki Linnakangas to use unsigned int not int64.
Back-patch to 9.4, where tuplesort.c grew the ability to sort as many
as INT_MAX tuples in-memory (commit 263865a48).
Discussion: https://postgr.es/m/20170629161637.1478.93109@wrigleys.postgresql.org
Commit 14e8803f1 removed the locking in SyncRepWaitForLSN, but that
introduced a race condition, where SyncRepWaitForLSN might see
syncRepState already set to SYNC_REP_WAIT_COMPLETE, but the process was
not yet removed from the queue. That tripped the assertion, that the
process should no longer be in the uqeue. Reorder the operations in
SyncRepWakeQueue to remove the process from the queue first, and update
syncRepState only after that, and add a memory barrier in between to make
sure the operations are made visible to other processes in that order.
Fixes bug #14721 reported by Const Zhang. Analysis and fix by Thomas Munro.
Backpatch down to 9.5, where the locking was removed.
Discussion: https://www.postgresql.org/message-id/20170629023623.1480.26508%40wrigleys.postgresql.org
We allow INSERT and UPDATE commands to assign to the same column more than
once, as long as the assignments are to subfields or elements rather than
the whole column. However, this failed when the target column was a domain
over array rather than plain array. Fix by teaching process_matched_tle()
to look through CoerceToDomain nodes, and add relevant test cases.
Also add a group of test cases exercising domains over array of composite.
It's doubtless accidental that CREATE DOMAIN allows this case while not
allowing straight domain over composite; but it does, so we'd better make
sure we don't break it. (I could not find any documentation mentioning
either side of that, so no doc changes.)
It's been like this for a long time, so back-patch to all supported
branches.
Discussion: https://postgr.es/m/4206.1499798337@sss.pgh.pa.us
We've heard occasional reports of backend launch failing because
pgwin32_ReserveSharedMemoryRegion() fails, indicating that something
has already used that address space in the child process. It's not
very clear what, given that we disable ASLR in Windows builds, but
suspicion falls on antivirus products. It'd be better if we didn't
have to disable ASLR, anyway. So let's try to ameliorate the problem
by retrying the process launch after such a failure, up to 100 times.
Patch by me, based on previous work by Amit Kapila and others.
This is a longstanding issue, so back-patch to all supported branches.
Discussion: https://postgr.es/m/CAA4eK1+R6hSx6t_yvwtx+NRzneVp+MRqXAdGJZChcau8Uij-8g@mail.gmail.com
It's possible for WalSndWaitForWal to be asked to wait for WAL that doesn't
exist yet. That's fine, in fact it's the normal situation if we're caught
up; but when the client requests shutdown we should not keep waiting.
The previous coding could wait indefinitely if the source server was idle.
In passing, improve the rather weak comments in this area, and slightly
rearrange some related code for better readability.
Back-patch to 9.4 where this code was introduced.
Discussion: https://postgr.es/m/14154.1498781234@sss.pgh.pa.us
Buildfarm evidence shows that TCP_KEEPALIVE_THRESHOLD doesn't exist
after all on Solaris < 11. This means we need to take positive action to
prevent the TCP_KEEPALIVE code path from being taken on that platform.
I've chosen to limit it with "&& defined(__darwin__)", since it's unclear
that anyone else would follow Apple's precedent of spelling the symbol
that way.
Also, follow a suggestion from Michael Paquier of eliminating code
duplication by defining a couple of intermediate symbols for the
socket option.
In passing, make some effort to reduce the number of translatable messages
by replacing "setsockopt(foo) failed" with "setsockopt(%s) failed", etc,
throughout the affected files. And update relevant documentation so
that it doesn't claim to provide an exhaustive list of the possible
socket option names.
Like the previous commit (f0256c774), back-patch to all supported branches.
Discussion: https://postgr.es/m/20170627163757.25161.528@wrigleys.postgresql.org
Commit 330b84d8c4 didn't contemplate the case where the public schema
has been dropped and introduced a query which fails when there is no
public schema into pg_dump (when used with -c).
Adjust the query used by pg_dump to handle the case where the public
schema doesn't exist and add tests to check that such a case no longer
fails.
Back-patch the specific fix to 9.6, as the prior commit was.
Adding tests for this case involved adding support to the pg_dump
TAP tests to work with multiple databases, which, while not a large
change, is a bit much to back-patch, so that's only done in master.
Addresses bug #14650
Discussion: https://www.postgresql.org/message-id/20170512181801.1795.47483%40wrigleys.postgresql.org
Turns out that the socket option for this is named TCP_KEEPALIVE_THRESHOLD,
at least according to the tcp(7P) man page for Solaris 11. (But since that
text refers to "SunOS", it's likely pretty ancient.) It appears that the
symbol TCP_KEEPALIVE does get defined on that platform, but it doesn't
seem to represent a valid protocol-level socket option. This leads to
bleats in the postmaster log, and no tcp_keepalives_idle functionality.
Per bug #14720 from Andrey Lizenko, as well as an earlier report from
Dhiraj Chawla that nobody had followed up on. The issue's been there
since we added the TCP_KEEPALIVE code path in commit 5acd417c8, so
back-patch to all supported branches.
Discussion: https://postgr.es/m/20170627163757.25161.528@wrigleys.postgresql.org
check_agg_arguments_walker threw an error upon seeing a SRF or window
function, but that is too aggressive: if the function is within a
sub-select then it's perfectly fine. I broke the SRF case in commit
0436f6bde by copying the logic for window functions ... but that was
broken too, and had been since commit eaccfded9.
Repair both cases in HEAD, and the window function case back to 9.3.
9.2 gets this right.
By default, wal_retrieve_retry_interval is five seconds, which is far
more than is needed in any of our TAP tests, leaving the test cases
just twiddling their thumbs for significant stretches. Moreover,
because it's so large, we get basically no testing of the retry-before-
master-is-ready code path. Hence, make PostgresNode::init set up
wal_retrieve_retry_interval = '500ms' as part of its customization of
test clusters' postgresql.conf. This shaves quite a few seconds off
the runtime of the recovery TAP tests.
Back-patch into 9.6. We have wal_retrieve_retry_interval in 9.5,
but the test infrastructure isn't there.
Discussion: https://postgr.es/m/31624.1498500416@sss.pgh.pa.us
When a walreceiver dies, the startup process will notice that and send
a PMSIGNAL_START_WALRECEIVER signal to the postmaster, asking for a new
walreceiver to be launched. There's a race condition, which at least
in HEAD is very easy to hit, whereby the postmaster might see that
signal before it processes the SIGCHLD from the walreceiver process.
In that situation, sigusr1_handler() just dropped the start request
on the floor, reasoning that it must be redundant. Eventually, after
10 seconds (WALRCV_STARTUP_TIMEOUT), the startup process would make a
fresh request --- but that's a long time if the connection could have
been re-established almost immediately.
Fix it by setting a state flag inside the postmaster that we won't
clear until we do launch a walreceiver. In cases where that results
in an extra walreceiver launch, it's up to the walreceiver to realize
it's unwanted and go away --- but we have, and need, that logic anyway
for the opposite race case.
I came across this through investigating unexpected delays in the
src/test/recovery TAP tests: it manifests there in test cases where
a master server is stopped and restarted while leaving streaming
slaves active.
This logic has been broken all along, so back-patch to all supported
branches.
Discussion: https://postgr.es/m/21344.1498494720@sss.pgh.pa.us
The stats collector disregards inquiry messages that bear a cutoff_time
before when it last wrote the relevant stats file. That's fine, but at
startup when it reads the "permanent" stats files, it absorbed their
timestamps as if they were the times at which the corresponding temporary
stats files had been written. In reality, of course, there's no data
out there at all. This led to disregarding inquiry messages soon after
startup if the postmaster had been shut down and restarted within less
than PGSTAT_STAT_INTERVAL; which is a pretty common scenario, both for
testing and in the field. Requesting backends would hang for 10 seconds
and then report failure to read statistics, unless they got bailed out
by some other backend coming along and making a newer request within
that interval.
I came across this through investigating unexpected delays in the
src/test/recovery TAP tests: it manifests there because the autovacuum
launcher hangs for 10 seconds when it can't get statistics at startup,
thus preventing a second shutdown from occurring promptly. We might
want to do some things in the autovac code to make it less prone to
getting stuck that way, but this change is a good bug fix regardless.
In passing, also fix pgstat_read_statsfiles() to ensure that it
re-zeroes its global stats variables if they are corrupted by a
short read from the stats file. (Other reads in that function
go into temp variables, so that the issue doesn't arise.)
This has been broken since we created the separation between permanent
and temporary stats files in 8.4, so back-patch to all supported branches.
Discussion: https://postgr.es/m/16860.1498442626@sss.pgh.pa.us
Fix its header comment, which described the old behavior of the <N>
phrase distance operator; we missed updating that in commit 028350f61.
Also, reset errno before strtol() call, to defend against the possibility
that it was already ERANGE at entry. (The lack of complaints says that
it generally isn't, but this is at least a latent bug.) Very minor
stylistic improvements as well.
Victor Drobny noted the obsolete comment, I noted the errno issue.
Back-patch to 9.6 where this code was added, just in case the errno
issue is a live bug in some cases.
Discussion: https://postgr.es/m/2b5382fdff9b1f79d5eb2c99c4d2cbe2@postgrespro.ru
When promoting a standby just after a XLOG_SWITCH record was replayed,
and next segment(s) are already are locally available (via walsender,
restore_command + trigger/recovery target), that segment could
accidentally be recycled onto the past of the new timeline. Later
checkpointer would create a .ready file for it, assuming there was an
error during creation, and it would get archived. That causes trouble
if another standby is later brought up from a basebackup from before
the timeline creation, because it would try to read the
segment, because XLogFileReadAnyTLI just tries all possible timelines,
which doesn't have valid contents. Thus replay would fail.
The problem, if already occurred, can be fixed by removing the segment
and/or having restore_command filter it out.
The reason for the creation of such "phantom" segments was, that after
an XLOG_SWITCH record the EndOfLog variable points to the beginning of
the next segment, and RemoveXlogFile() used XLByteToPrevSeg().
Normally RemoveXlogFile() doing so is harmless, because the last
segment will still exist preventing InstallXLogFileSegment() from
causing harm, but just after promotion there's no previous segment on
the new timeline.
Fix that by using XLByteToSeg() instead of XLByteToPrevSeg().
Author: Andres Freund
Reported-By: Greg Burek
Discussion: https://postgr.es/m/20170619073026.zcwpe6mydsaz5ygd@alap3.anarazel.de
Backpatch: 9.2-, bug older than all supported versions
When commit 0f33a719fd removed the
instructions to start/stop the new cluster before running rsync, it was
now possible for pg_resetwal/pg_resetxlog to leave the final WAL record
at wal_level=minimum, preventing upgraded standby servers from
reconnecting.
This patch fixes that by having pg_upgrade unconditionally start/stop
the new cluster after pg_resetwal/pg_resetxlog has run.
Backpatch through 9.2 since, though the instructions were added in PG
9.5, they worked all the way back to 9.2.
Discussion: https://postgr.es/m/20170620171844.GC24975@momjian.us
Backpatch-through: 9.2
When materialized views were added, psql's \d commands were made to
treat them as a separate object category ... but not everyplace in the
documentation or comments got the memo.
Noted by David Johnston. Back-patch to 9.3 where matviews came in.
Discussion: https://postgr.es/m/CAKFQuwb27M3VXRhHErjCpkWwN9eKThbqWb1=trtoXi9_ejqPXQ@mail.gmail.com
David Rowley found that the "use the smallest per-column selectivity"
heuristic applied in some cases by get_foreign_key_join_selectivity()
was badly off if the FK columns are independent, producing estimates
much worse than we got before that code was added in 9.6.
One case where that heuristic was used was for LEFT and FULL outer joins
with the referenced rel on the outside of the join. But we should not
really need to special-case those here. eqjoinsel() never has had such a
special case; the correction is applied by calc_joinrel_size_estimate()
instead. Let's just estimate such cases like inner joins and rely on that
later adjustment. (I think there was something of a thinko here, in that
the comments seem to be thinking about the selectivity as defined for
semi/anti joins; but that shouldn't apply to left/full joins.) Add a
regression test exercising such a case to show that this is sane in
at least some cases.
The other case where we used that heuristic was for SEMI/ANTI outer joins,
either if the referenced rel was on the outside, or if it was on the inside
but was part of a join within the RHS. In either case, the FK doesn't give
us a lot of traction towards estimating the selectivity. To ensure that
we don't have regressions from what happened before 9.6, let's punt by
ignoring the FK in such cases and applying the traditional selectivity
calculation. (We might be able to improve on that later, but for now
I just want to be sure it's not worse than 9.5.)
Report and patch by David Rowley, simplified a bit by me. Back-patch
to 9.6 where this code was added.
Discussion: https://postgr.es/m/CAKJS1f8NO8oCDcxrteohG6O72uU1saEVT9qX=R8pENr5QWerXw@mail.gmail.com
The combination of -Z -Fp and output to stdout resulted in corrupted
output data, because we left stdout in text mode, resulting in newline
conversion being done on the compressed stream. Switch stdout to binary
mode for this case, at the same place where we do it for non-text output
formats.
Report and patch by Kuntal Ghosh, tested by Ashutosh Sharma and Neha
Sharma. Back-patch to all supported branches.
Discussion: https://postgr.es/m/CAGz5QCJPvbBjXAmJuGx1B_41yVCetAJhp7rtaDf7XQGWuB1GSw@mail.gmail.com
When, during logical decoding, a transaction gets too big, it's
contents get spilled to disk. Not just the top-transaction gets
spilled, but *also* all of its subtransactions, even if they're not
that large themselves. Unfortunately we didn't clean up
such small spilled subtransactions from disk.
Fix that, by keeping better track of whether a transaction has been
spilled to disk.
Author: Andres Freund
Reported-By: Dmitriy Sarafannikov, Fabrízio de Royes Mello
Discussion:
https://postgr.es/m/1457621358.355011041@f382.i.mail.ruhttps://postgr.es/m/CAFcNs+qNMhNYii4nxpO6gqsndiyxNDYV0S=JNq0v_sEE+9PHXg@mail.gmail.com
Backpatch: 9.4-, where logical decoding was introduced
When a new base type is created using the old-style procedure of first
creating the input/output functions with "opaque" in place of the base
type, the "opaque" argument/return type is changed to the final base type,
on CREATE TYPE. However, we did not create a pg_depend record when doing
that, so the functions were left not depending on the type.
Fixes bug #14706, reported by Karen Huddleston.
Discussion: https://www.postgresql.org/message-id/20170614232259.1424.82774@wrigleys.postgresql.org
We had three occurrences of essentially the same coding pattern
wherein we tried to retrieve a query result from a libpq connection
without blocking. In the case where PQconsumeInput failed (typically
indicating a lost connection), all three loops simply gave up and
returned, forgetting to clear any previously-collected PGresult
object. Since those are malloc'd not palloc'd, the oversight results
in a process-lifespan memory leak.
One instance, in libpqwalreceiver, is of little significance because
the walreceiver process would just quit anyway if its connection fails.
But we might as well fix it.
The other two instances, in postgres_fdw, are somewhat more worrisome
because at least in principle the scenario could be repeated, allowing
the amount of memory leaked to build up to something worth worrying
about. Moreover, in these cases the loops contain CHECK_FOR_INTERRUPTS
calls, as well as other calls that could potentially elog(ERROR),
providing another way to exit without having cleared the PGresult.
Here we need to add PG_TRY logic similar to what exists in quite a
few other places in postgres_fdw.
Coverity noted the libpqwalreceiver bug; I found the other two cases
by checking all calls of PQconsumeInput.
Back-patch to all supported versions as appropriate (9.2 lacks
postgres_fdw, so this is really quite unexciting for that branch).
Discussion: https://postgr.es/m/22620.1497486981@sss.pgh.pa.us
During pg_upgrade's restore run, all relfilenode choices should be
overridden by commands in the dump script. If we ever find ourselves
choosing a relfilenode in the ordinary way, someone blew it. Likewise for
pg_type OIDs. Since pg_upgrade might well succeed anyway, if there happens
not to be a conflict during the regression test run, we need assertions
here to keep us on the straight and narrow.
We might someday be able to remove the assertion in GetNewRelFileNode,
if pg_upgrade is rewritten to remove its assumption that old and new
relfilenodes always match. But it's hard to see how to get rid of the
pg_type OID constraint, since those OIDs are embedded in user tables
in some cases.
Back-patch as far as 9.5, because of the risk of back-patches breaking
something here even if it works in HEAD. I'd prefer to go back further,
but 9.4 fails both assertions due to get_rel_infos()'s use of a temporary
table. We can't use the later-branch solution of a CTE for compatibility
reasons (cf commit 5d16332e9), and it doesn't seem worth inventing some
other way to do the query. (I did check, by dint of changing the Asserts
to elog(WARNING), that there are no other cases of unwanted OID assignments
during 9.4's regression test run.)
Discussion: https://postgr.es/m/19785.1497215827@sss.pgh.pa.us
If authentication over an SSL connection fails, with sslmode=prefer,
libpq will reconnect without SSL and retry. However, we did not clear
the variables related to GSS, SSPI, and SASL authentication state, when
reconnecting. Because of that, the second authentication attempt would
always fail with a "duplicate GSS/SASL authentication request" error.
pg_SSPI_startup did not check for duplicate authentication requests like
the corresponding GSS and SASL functions, so with SSPI, you would leak
some memory instead.
Another way this could manifest itself, on version 10, is if you list
multiple hostnames in the "host" parameter. If the first server requests
Kerberos or SCRAM authentication, but it fails, the attempts to connect to
the other servers will also fail with "duplicate authentication request"
errors.
To fix, move the clearing of authentication state from closePGconn to
pgDropConnection, so that it is cleared also when re-connecting.
Patch by Michael Paquier, with some kibitzing by me.
Backpatch down to 9.3. 9.2 has the same bug, but the code around closing
the connection is somewhat different, so that this patch doesn't apply.
To fix this in 9.2, I think we would need to back-port commit 210eb9b743
first, and then apply this patch. However, given that we only bumped into
this in our own testing, we haven't heard any reports from users about
this, and that 9.2 will be end-of-lifed in a couple of months anyway, it
doesn't seem worth the risk and trouble.
Discussion: https://www.postgresql.org/message-id/CAB7nPqRuOUm0MyJaUy9L3eXYJU3AKCZ-0-03=-aDTZJGV4GyWw@mail.gmail.com
Because walsender and normal backends share the same main loop it's
problematic to have two different flag variables, set in signal
handlers, indicating a pending configuration reload. Only certain
walsender commands reach code paths checking for the
variable (START_[LOGICAL_]REPLICATION, CREATE_REPLICATION_SLOT
... LOGICAL, notably not base backups).
This is a bug present since the introduction of walsender, but has
gotten worse in releases since then which allow walsender to do more.
A later patch, not slated for v10, will similarly unify SIGHUP
handling in other types of processes as well.
Author: Petr Jelinek, Andres Freund
Reviewed-By: Michael Paquier
Discussion: https://postgr.es/m/20170423235941.qosiuoyqprq4nu7v@alap3.anarazel.de
Backpatch: 9.2-, bug is present since 9.0
When the checkpointer writes the shutdown checkpoint, it checks
afterwards whether any WAL has been written since it started and
throws a PANIC if so. At that point, only walsenders are still
active, so one might think this could not happen, but walsenders can
also generate WAL, for instance in BASE_BACKUP and logical decoding
related commands (e.g. via hint bits). So they can trigger this panic
if such a command is run while the shutdown checkpoint is being
written.
To fix this, divide the walsender shutdown into two phases. First,
checkpointer, itself triggered by postmaster, sends a
PROCSIG_WALSND_INIT_STOPPING signal to all walsenders. If the backend
is idle or runs an SQL query this causes the backend to shutdown, if
logical replication is in progress all existing WAL records are
processed followed by a shutdown. Otherwise this causes the walsender
to switch to the "stopping" state. In this state, the walsender will
reject any further replication commands. The checkpointer begins the
shutdown checkpoint once all walsenders are confirmed as
stopping. When the shutdown checkpoint finishes, the postmaster sends
us SIGUSR2. This instructs walsender to send any outstanding WAL,
including the shutdown checkpoint record, wait for it to be replicated
to the standby, and then exit.
Author: Andres Freund, based on an earlier patch by Michael Paquier
Reported-By: Fujii Masao, Andres Freund
Reviewed-By: Michael Paquier
Discussion: https://postgr.es/m/20170602002912.tqlwn4gymzlxpvs2@alap3.anarazel.de
Backpatch: 9.4, where logical decoding was introduced
The non-participation in procsignal was a problem for both changes in
master, e.g. parallelism not working for normal statements run in
walsender backends, and older branches, e.g. recovery conflicts and
catchup interrupts not working for logical decoding walsenders.
This commit thus replaces the previous WalSndXLogSendHandler with
procsignal_sigusr1_handler. In branches since db0f6cad48 that can
lead to additional SetLatch calls, but that only rarely seems to make
a difference.
Author: Andres Freund
Reviewed-By: Michael Paquier
Discussion: https://postgr.es/m/20170421014030.fdzvvvbrz4nckrow@alap3.anarazel.de
Backpatch: 9.4, earlier commits don't seem to benefit sufficiently
The current method of computing the record length (excluding the
lenght of full-page images) has been wrong since the WAL format has
been revamped in 2c03216d83. Only the
main record's length was counted, but that can be significantly too
little if there's data associated with further blocks.
Fix by computing the record length as total_lenght - fpi_length.
Reported-By: Chen Huajun
Bug: #14687
Reviewed-By: Heikki Linnakangas
Discussion: https://postgr.es/m/20170603165939.1436.58887@wrigleys.postgresql.org
Backpatch: 9.5-
Some openssl builds put their lib files in a VC subdirectory, others do
not. Cater for both cases.
Backpatch to all live branches.
From an offline discussion with Leonardo Cecchi.
Previously this was not allowed, as copy.c didn't set the
CURSOR_OPT_PARALLEL_OK flag when planning the query. Set it.
While the lack of parallel query for COPY isn't strictly speaking a
bug, it does prevent parallelism from being used in a facility
commonly used to run long running queries. Thus backpatch to 9.6.
Author: Andres Freund
Discussion: https://postgr.es/m/20170531231958.ihanapplorptykzm@alap3.anarazel.de
Backpatch: 9.6, where parallelism was introduced.
On some platforms, -fpic fails for sufficiently large shared libraries.
We've mostly not hit that boundary yet, but there are some extensions
such as Citus and pglogical where it's becoming a problem. A bit of
research suggests that the penalty for -fPIC is small, in the
single-digit-percentage range --- and there's none at all on popular
platforms such as x86_64. So let's just default to -fPIC everywhere
and provide one less thing for extension developers to worry about.
Per complaint from Christoph Berg. Back-patch to all supported branches.
(I did not bother to touch the recently-removed Makefiles for sco and
unixware in the back branches, though. We'd have no way to test that
it doesn't break anything on those platforms.)
Discussion: https://postgr.es/m/20170529155850.qojdfrwkkqnjb3ap@msg.df7cb.de
Remove some gratuituous message differences by making the AM name
previously embedded in each message be a %s instead. While at it, get
rid of terminology that's unclear and unnecessary in one message.
Discussion: https://postgr.es/m/20170523001557.bq2hbq7hxyvyw62q@alvherre.pgsql
pg_resetwal (formerly pg_resetxlog) doesn't insist on finding a matching
version number in pg_control, and that seems like an important thing to
preserve since recovering from corrupt pg_control is a prime reason to
need to run it. However, that means you can try to run it against a
data directory of a different major version, which is at best useless
and at worst disastrous. So as to provide some protection against that
type of pilot error, inspect PG_VERSION at startup and refuse to do
anything if it doesn't match. PG_VERSION is read-only after initdb,
so it's unlikely to get corrupted, and even if it were corrupted it would
be easy to fix by hand.
This hazard has been there all along, so back-patch to all supported
branches.
Michael Paquier, with some kibitzing by me
Discussion: https://postgr.es/m/f4b8eb91-b934-8a0d-b3cc-68f06e2279d1@enterprisedb.com
The NumericOnly grammar production accepted ICONST, + ICONST, - ICONST,
FCONST, and - FCONST, but for some reason not + FCONST. This led to
strange inconsistencies like
regression=# set random_page_cost = +4;
SET
regression=# set random_page_cost = 4000000000;
SET
regression=# set random_page_cost = +4000000000;
ERROR: syntax error at or near "4000000000"
(because 4000000000 is too large to be an ICONST). While there's
no actual functional reason to need to write a "+", if we allow
it for integers it seems like we should allow it for numerics too.
It's been like that forever, so back-patch to all supported branches.
Discussion: https://postgr.es/m/30908.1496006184@sss.pgh.pa.us
Commit 9aa3c782c added code to allow CREATE TABLE/CREATE TYPE to not fail
when the desired type name conflicts with an autogenerated array type, by
dint of renaming the array type out of the way. But I (tgl) overlooked
that the same case arises in ALTER TABLE/TYPE RENAME. Fix that too.
Back-patch to all supported branches.
Report and patch by Vik Fearing, modified a bit by me
Discussion: https://postgr.es/m/0f4ade49-4f0b-a9a3-c120-7589f01d1eb8@2ndquadrant.com
If an operator class has no operators or functions, and doesn't need
a STORAGE clause, we emitted "CREATE OPERATOR CLASS ... AS ;" which
is syntactically invalid. Fix by forcing a STORAGE clause to be
emitted anyway in this case.
(At some point we might consider changing the grammar to allow CREATE
OPERATOR CLASS without an opclass_item_list. But probably we'd want to
omit the AS in that case, so that wouldn't fix this pg_dump issue anyway.)
It's been like this all along, so back-patch to all supported branches.
Daniel Gustafsson, tweaked by me to avoid a dangling-pointer bug
Discussion: https://postgr.es/m/D9E5FC64-7A37-4F3D-B946-7E4FB468F88A@yesql.se
This patch replaces isspace() calls with scanner_isspace() in functions
that are likely to be presented with non-ASCII input. isspace() has
the small advantage that it will correctly recognize no-break space
in single-byte encodings (such as LATIN1); but it cannot work successfully
for any multibyte character, and depending on platform it might return
false positive results for some fragments of multibyte characters. That's
disastrous for functions that are trying to discard whitespace between
valid strings, as noted in bug #14662 from Justin Muise. Even treating
no-break space as whitespace is pretty questionable for the usages touched
here, because the core scanner would think it is an identifier character.
Affected functions are parse_ident(), parseNameAndArgTypes (underlying
regprocedurein() and siblings), SplitIdentifierString (used for parsing
GUCs and options that are qualified names or lists of names), and
SplitDirectoriesString (used for parsing GUCs that are lists of
directories).
All the functions adjusted here are parsing SQL identifiers and similar
constructs, so it's reasonable to insist that their definition of
whitespace match the core scanner. So we can hope that this won't cause
many backwards-compatibility problems. I've left alone isspace() calls
in places that aren't really expecting any non-ASCII input characters,
such as float8in().
Back-patch to all supported branches.
Discussion: https://postgr.es/m/10129.1495302480@sss.pgh.pa.us
The cash_div_intX functions applied rint() to the result of the division.
That's not merely useless (because the result is already an integer) but
it causes precision loss for values larger than 2^52 or so, because of
the forced conversion to float8.
On the other hand, the cash_mul_fltX functions neglected to apply rint() to
their multiplication results, thus possibly causing off-by-one outputs.
Per C standard, arithmetic between any integral value and a float value is
performed in float format. Thus, cash_mul_flt4 and cash_div_flt4 produced
answers good to only about six digits, even when the float value is exact.
We can improve matters noticeably by widening the float inputs to double.
(It's tempting to consider using "long double" arithmetic if available,
but that's probably too much of a stretch for a back-patched fix.)
Also, document that cash_div_intX operators truncate rather than round.
Per bug #14663 from Richard Pistole. Back-patch to all supported branches.
Discussion: https://postgr.es/m/22403.1495223615@sss.pgh.pa.us
When stdin is a terminal, it's possible to end a COPY FROM STDIN with
a keyboard EOF signal (typically control-D), and then keep on issuing
SQL commands. One would expect another COPY FROM STDIN to work as well,
but on some platforms it did not. This turns out to be because we were
not resetting the stream's feof() flag, and BSD-ish versions of fread()
and fgets() won't attempt to read more data if that's set.
The misbehavior is observed on BSDen (including macOS), but not Linux,
Windows, or SysV-ish Unixen, which makes this a portability bug not
just a missing feature.
Add a clearerr() call to fix the behavior, and improve the prompt that's
issued when copying from a TTY to mention that EOF signals work.
It's been like this forever, so back-patch to all supported branches.
Thomas Munro
Discussion: https://postgr.es/m/CAEepm=0MCGfYf=JAMiYhO6JPtv9-3ZfBo8fcGeCZ8oMzaw+Z+Q@mail.gmail.com
Modifying the permissions of a persistent file isn't really much nicer
than modifying its contents, even if git doesn't currently notice it.
Adjust the test script to make a copy and set the permissions of that
instead.
Michael Paquier, per a gripe from me. Back-patch to 9.5 where these
tests were introduced.
Discussion: https://postgr.es/m/14836.1494885946@sss.pgh.pa.us
The CommentStmt made by RebuildConstraintComment() has to pstrdup the
relation name, else it will contain a dangling pointer after that
relcache entry is flushed. (I'm less sure that pstrdup'ing conname
is necessary, but let's be safe.) Failure to do this leads to weird
errors or crashes, as reported by Marko Elezovic.
Bug introduced by commit e42375fc8, so back-patch to 9.5 as that was.
Fix by David Rowley, regression test by Michael Paquier
Discussion: https://postgr.es/m/DB6PR03MB30775D58E732D4EB0C13725B9AE00@DB6PR03MB3077.eurprd03.prod.outlook.com
Commit 60690a6fe attempted to fix the wait_for_stats() function in this
test so that it would wait properly if the tenk2 scans were done in
parallel workers instead of the main session (typically as a consequence of
force_parallel_mode being turned on). However, we made it test for whether
the main session's actions had been reported by looking for inserts on
'trunc_stats_test'. This is the Wrong Thing, because those aren't the last
updates we expect the main session to do. As shown by recent failures on
buildfarm member frogmouth, it's entirely likely that the trunc_stats_test
updates will be reported in a separate message from later updates, which
means there can be a window in which wait_for_stats() will exit but not all
the updates we are expecting to see will have arrived. We should test for
the last updates we're expecting, namely those on 'trunc_stats_test4'.
Unfortunately, I doubt that this explains frogmouth's failures, because
there's no reason to believe that it's running the tenk2 queries in
parallel. Still, the test is wrong on its own terms, so fix and back-patch
to 9.6 where parallel query came in.
Before 955a684e04 logical decoding snapshot maintenance needed to
cope with transactions it might not have seen in their entirety. For
such transactions we'd to assume they modified the catalog (could have
happened before we were watching), and thus a new snapshot had to be
built, and distributed to concurrently running transactions.
That's problematic because building a new snapshot isn't that cheap ,
especially as the the array of committed transactions needs to be
sorted. When creating a slot on a server with a lot of transactions,
this could make logical slot creation infeasibly expensive.
After 955a684e04 there's no need to deal with transaction that
aren't guaranteed to be fully observable. That allows to avoid
building snapshots for transactions that haven't modified catalog,
even before reaching consistency.
While this isn't necessarily a bugfix, slot creation being impossible
in some production workloads, is severe enough to warrant
backpatching.
Author: Andres Freund, based on a quite different patch from Petr Jelinek
Analyzed-By: Petr Jelinek
Reviewed-By: Petr Jelinek
Discussion: https://postgr.es/m/f37e975c-908f-858e-707f-058d3b1eb214@2ndquadrant.com
Backpatch: 9.4-, where logical decoding has been introduced
The snapshot assembly during the creation of logical slots relied
waiting for transactions in xl_running_xacts to end, by checking for
their commit/abort records. Unfortunately, despite locking, it is
possible to see an xl_running_xact record listing transactions as
ready, that have already WAL-logged an commit/abort record, as the
locking just prevents the ProcArray to be adjusted, and the commit
record has to be logged first.
That lead to either delayed or hanging snapshot creation, because
snapbuild.c would wait "forever" to see commit/abort records for some
transactions. That hang resolved only if a xl_running_xacts record
without any running transactions happened to be logged, far from
certain on a busy server.
It's impractical to prevent that via more heavyweight locking, the
likelihood of deadlocks and significantly increased contention would
be too big.
Instead change the initial snapshot creation to be solely based on
tracking the oldest running transaction via
xl_running_xacts->oldestRunningXid - that actually ends up
significantly simplifying the code. That has two disadvantages:
1) Because we cannot fully "trust" the contents of xl_running_xacts,
we cannot use it to build the initial snapshot. Instead we have to
wait twice for all running transactions to finish.
2) Previously a slot, unless the race occurred, could be created when
the all transaction perceived as running based on commit/abort
records, now we have to wait for the next xl_running_xacts record.
To address that, trigger logging new xl_running_xacts record from
within snapbuild.c exactly when necessary.
Unfortunately snabuild.c's SnapBuild is stored on disk, one of the
stupider ideas of a certain Mr Freund, so we can't change it in a
minor release. As this is going to be backpatched, we have to hack
around a bit to keep on-disk compatibility. A later commit will
rejigger that on master.
Author: Andres Freund, based on a quite different patch from Petr Jelinek
Analyzed-By: Petr Jelinek
Reviewed-By: Petr Jelinek
Discussion: https://postgr.es/m/f37e975c-908f-858e-707f-058d3b1eb214@2ndquadrant.com
Backpatch: 9.4-, where logical decoding has been introduced
We have now grown enough registerable syscache-invalidation callback
functions that the original assumption that there would be few of them
is causing performance problems. In particular, let's fix things so that
CallSyscacheCallbacks doesn't have to search the whole array to find
which callback(s) to invoke for a given cache ID. Preserve the original
behavior that callbacks are called in order of registration, just in
case there's someplace that depends on that (which I doubt).
In support of this, export the number of syscaches from syscache.h.
People could have found that out anyway from the enum, but adding a
#define makes that much safer.
This provides a useful additional speedup in Mathieu Fenniak's
logical-decoding test case, although we're reaching the point of
diminishing returns there. I think any further improvement will have
to come from reducing the number of cache invalidations that are
triggered in the first place. Still, we can hope that this change
gives some incremental benefit for all invalidation scenarios.
Back-patch to 9.4 where logical decoding was introduced.
Discussion: https://postgr.es/m/CAHoiPjzea6N0zuCi=+f9v_j94nfsy6y8SU7-=bp4=7qw6_i=Rg@mail.gmail.com
A test case provided by Mathieu Fenniak shows that hash_seq_search'ing
this hashtable can consume a very significant amount of overhead during
logical decoding, which triggers frequent cache invalidation. Testing
suggests that the actual population of the hashtable is often no more
than a few dozen entries, so we can cut the overhead just by dropping
the initial number of buckets down from 1024 --- I chose to cut it to 64.
(In situations where we do have a significant number of entries, we
shouldn't get any real penalty from doing this, as the dynahash.c code
will resize the hashtable automatically.)
This gives a further factor-of-two savings in Mathieu's test case.
That may be overly optimistic for real-world benefit, as real cases
may have larger average table populations, but it's hard to see it
turning into a net negative for any workload.
Back-patch to 9.4 where relfilenodemap.c was introduced.
Discussion: https://postgr.es/m/CAHoiPjzea6N0zuCi=+f9v_j94nfsy6y8SU7-=bp4=7qw6_i=Rg@mail.gmail.com
A test case provided by Mathieu Fenniak shows that the initial search for
the target catcache in CatalogCacheIdInvalidate consumes a very significant
amount of overhead in cases where cache invalidation is triggered but has
little useful work to do. There is no good reason for that search to exist
at all, as the index array maintained by syscache.c allows direct lookup of
the catcache from its ID. We just need a frontend function in syscache.c,
matching the division of labor for most other cache-accessing operations.
While there's more that can be done in this area, this patch alone reduces
the runtime of Mathieu's example by 2X. We can hope that it offers some
useful benefit in other cases too, although usually cache invalidation
overhead is not such a striking fraction of the total runtime.
Back-patch to 9.4 where logical decoding was introduced. It might be
worth going further back, but presently the only case we know of where
cache invalidation is really a significant burden is in logical decoding.
Also, older branches have fewer catcaches, reducing the possible benefit.
(Note: although this nominally changes catcache's API, we have always
documented CatalogCacheIdInvalidate as a private function, so I would
have little sympathy for an external module calling it directly. So
backpatching should be fine.)
Discussion: https://postgr.es/m/CAHoiPjzea6N0zuCi=+f9v_j94nfsy6y8SU7-=bp4=7qw6_i=Rg@mail.gmail.com
On MSVC builds and on back branches that means removing the hardcoded
--verbose setting. On master for Unix that means removing the empty
setting in the global Makefile so that the value can be acquired from
the environment as well as from the make arguments.
Backpatch to 9.4 where we introduced TAP tests
On Unix this path is detected via the use of xml2-config, but that's not
available on Windows. This means that users building with libxml2 will
no longer need to move things around from the standard libxml2
installation for MSVC builds.
Backpatch to all live branches.
Increase from the historical value of 32 to 64. We are up to 31 callers
of CacheRegisterSyscacheCallback() in HEAD, so if they were all to be
exercised in one process that would leave only one slot for add-on modules.
It's probably not possible for that to happen, but still we clearly need
more daylight here. (At some point it might be worth making the array
dynamically resizable; but since we've never heard a complaint of "out of
syscache_callback_list slots" happening in the field, I doubt it's worth
it yet.)
Back-patch as far as 9.4, which is where we increased the companion limit
MAX_RELCACHE_CALLBACKS (cf commit f01d1ae3a). It's not as urgent in
released branches, which have only a couple dozen call sites in core, but
it still seems that somebody might hit the limit before these branches die.
Discussion: https://postgr.es/m/12184.1494450131@sss.pgh.pa.us
Values in a STATISTIC_KIND_RANGE_LENGTH_HISTOGRAM slot are float8,
not of the type of the column the statistics are for.
This bug is at least partly the fault of sloppy specification comments
for get_attstatsslot()/free_attstatsslot(): the type OID they want is that
of the stavalues entries, not of the underlying column. (I double-checked
other callers and they seem to get this right.) Adjust the comments to be
more correct.
Per buildfarm.
Security: CVE-2017-7484
Both views replace the umoptions field with NULL when the user does not
meet qualifications to see it. They used different qualifications, and
pg_user_mappings documented qualifications did not match its implemented
qualifications. Make its documentation and implementation match those
of user_mapping_options. One might argue for stronger qualifications,
but these have long, documented tenure. pg_user_mappings has always
exhibited this problem, so back-patch to 9.2 (all supported versions).
Michael Paquier and Feike Steenbergen. Reviewed by Jeff Janes.
Reported by Andrew Wheelwright.
Security: CVE-2017-7486
Commit 65c3bf19fd moved handling of the,
already then, deprecated requiressl parameter into conninfo_storeval().
The default PGREQUIRESSL environment variable was however lost in the
change resulting in a potentially silent accept of a non-SSL connection
even when set. Its documentation remained. Restore its implementation.
Also amend the documentation to mark PGREQUIRESSL as deprecated for
those not following the link to requiressl. Back-patch to 9.3, where
commit 65c3bf1 first appeared.
Behavior has been more complex when the user provides both deprecated
and non-deprecated settings. Before commit 65c3bf1, libpq operated
according to the first of these found:
requiressl=1
PGREQUIRESSL=1
sslmode=*
PGSSLMODE=*
(Note requiressl=0 didn't override sslmode=*; it would only suppress
PGREQUIRESSL=1 or a previous requiressl=1. PGREQUIRESSL=0 had no effect
whatsoever.) Starting with commit 65c3bf1, libpq ignored PGREQUIRESSL,
and order of precedence changed to this:
last of requiressl=* or sslmode=*
PGSSLMODE=*
Starting now, adopt the following order of precedence:
last of requiressl=* or sslmode=*
PGSSLMODE=*
PGREQUIRESSL=1
This retains the 65c3bf1 behavior for connection strings that contain
both requiressl=* and sslmode=*. It retains the 65c3bf1 change that
either connection string option overrides both environment variables.
For the first time, PGSSLMODE has precedence over PGREQUIRESSL; this
avoids reducing security of "PGREQUIRESSL=1 PGSSLMODE=verify-full"
configurations originating under v9.3 and later.
Daniel Gustafsson
Security: CVE-2017-7485
Some selectivity estimation functions run user-supplied operators over
data obtained from pg_statistic without security checks, which allows
those operators to leak pg_statistic data without having privileges on
the underlying tables. Fix by checking that one of the following is
satisfied: (1) the user has table or column privileges on the table
underlying the pg_statistic data, or (2) the function implementing the
user-supplied operator is leak-proof. If neither is satisfied, planning
will proceed as if there are no statistics available.
At least one of these is satisfied in most cases in practice. The only
situations that are negatively impacted are user-defined or
not-leak-proof operators on a security-barrier view.
Reported-by: Robert Haas <robertmhaas@gmail.com>
Author: Peter Eisentraut <peter_e@gmx.net>
Author: Tom Lane <tgl@sss.pgh.pa.us>
Security: CVE-2017-7484
The upstream IANA code does not guard against null TM_ZONE pointers in this
function, but in our code there is such a check in the other pre-existing
use of t->tm_zone. We do have some places that set pg_tm.tm_zone to NULL.
I'm not entirely sure it's possible to reach strftime with such a value,
but I'm not sure it isn't either, so be safe.
Per Coverity complaint.
Somehow, we'd missed ever doing this. The consequences aren't too
severe: basically, the timezone library would fall back on its hardwired
notion of the DST transition dates to use for a POSIX-style zone name,
rather than obeying US/Eastern which is the intended behavior. The net
effect would only be to obey current US DST law further back than it
ought to apply; so it's not real surprising that nobody noticed.
David Rowley, per report from Amit Kapila
Discussion: https://postgr.es/m/CAA4eK1LC7CaNhRAQ__C3ht1JVrPzaAXXhEJRnR5L6bfYHiLmWw@mail.gmail.com
Fix oversight in commit af2c5aa88: if the shortcut open() doesn't work,
we need to reset fullname[] to be just the name of the toplevel tzdata
directory before we fall through into the pre-existing code. This failed
to be exposed in my (tgl's) testing because the fall-through path is
actually never taken under normal circumstances.
David Rowley, per report from Amit Kapila
Discussion: https://postgr.es/m/CAA4eK1LC7CaNhRAQ__C3ht1JVrPzaAXXhEJRnR5L6bfYHiLmWw@mail.gmail.com
buildDefaultACLCommands() didn't destroy the string buffer created in
certain cases, leading to a memory leak. Fix by destroying the buffer
before returning from the function.
Spotted by Coverity.
Author: Michael Paquier
Back-patch to 9.6 where buildDefaultACLCommands() was added.
When we add the SELECT-privilege based policies to the RLS with check
options (such as for an UPDATE statement, or when we have INSERT ...
RETURNING), we need to be sure and use the 'USING' case if the policy is
actually an 'ALL' policy (which could have both a USING clause and an
independent WITH CHECK clause).
This could result in policies acting differently when built using ALL
(when the ALL had both USING and WITH CHECK clauses) and when building
the policies independently as SELECT and UPDATE policies.
Fix this by adding an explicit boolean to add_with_check_options() to
indicate when the USING policy should be used, even if the policy has
both USING and WITH CHECK policies on it.
Reported by: Rod Taylor
Back-patch to 9.5 where RLS was introduced.
Commit eaba54c20c added support for Tcl 8.6 for configure-supported
platforms after verifying that pltcl works without further changes, but
the MSVC tooling wasn't updated accordingly. Update MSVC to match,
restructuring the code to avoid duplicating the logic for every Tcl
version supported.
Backpatch to all live branches, like eaba54c20c. In 9.4 and previous,
change the patch to use backslashes rather than forward, as in the rest
of the file.
Reported by Paresh More, who also tested the patch I provided.
Discussion: https://postgr.es/m/CAAgiCNGVw3ssBtSi3ZNstrz5k00ax=UV+_ZEHUeW_LMSGL2sew@mail.gmail.com
It only produced <row> elements but no wrapping <table> element.
By contrast, cursor_to_xmlschema produced a schema that is now correct
but did not previously match the XML data produced by cursor_to_xml.
In passing, also fix a minor misunderstanding about moving cursors in
the tests related to this.
Reported-by: filip@jirsak.org
Based-on-patch-by: Thomas Munro <thomas.munro@enterprisedb.com>
GiST's getNextNearest() function attempts to pfree the previously-returned
tuple if any (that is, scan->xs_hitup in HEAD, or scan->xs_itup in older
branches). However, if we are rescanning a plan node after ending a
previous scan early, those tuple pointers could be pointing to garbage,
because they would be pointing into the scan's pageDataCxt or queueCxt
which has been reset. In a debug build this reliably results in a crash,
although I think it might sometimes accidentally fail to fail in
production builds.
To fix, clear the pointer field anyplace we reset a context it might
be pointing into. This may be overkill --- I think probably only the
queueCxt case is involved in this bug, so that resetting in gistrescan()
would be sufficient --- but dangling pointers are generally bad news,
so let's avoid them.
Another plausible answer might be to just not bother with the pfree in
getNextNearest(). The reconstructed tuples would go away anyway in the
context resets, and I'm far from convinced that freeing them a bit earlier
really saves anything meaningful. I'll stick with the original logic in
this patch, but if we find more problems in the same area we should
consider that approach.
Per bug #14641 from Denis Smirnov. Back-patch to 9.5 where this
logic was introduced.
Discussion: https://postgr.es/m/20170504072034.24366.57688@wrigleys.postgresql.org
This removes a test case added by commit b69ec7cc9, which was intended
to exercise a corner case involving the rule used at that time that
materialized views were unpopulated iff they had physical size zero.
We got rid of that rule very shortly later, in commit 1d6c72a55, but
kept the test case. However, because the case now asks what VACUUM
will do to a zero-sized physical file, it would be pretty surprising
if the answer were ever anything but "nothing" ... and if things were
indeed that broken, surely we'd find it out from other tests. Since
the test involves a table that's fairly large by regression-test
standards (100K rows), it's quite slow to run. Dropping it should
save some buildfarm cycles, so let's do that.
Discussion: https://postgr.es/m/32386.1493831320@sss.pgh.pa.us
tzparse() would attempt to load the "posixrules" timezone database file on
each call. That might seem like it would only be an issue when selecting a
POSIX-style zone name rather than a zone defined in the timezone database,
but it turns out that each zone definition file contains a POSIX-style zone
string and tzload() will call tzparse() to parse that. Thus, when scanning
the whole timezone file tree as we do in the pg_timezone_names view,
"posixrules" was read repetitively for each zone definition file. Fix
that by caching the file on first use within any given process. (We cache
other zone definitions for the life of the process, so there seems little
reason not to cache this one as well.) This probably won't help much in
processes that never run pg_timezone_names, but even one additional SET
of the timezone GUC would come out ahead.
An even worse problem for pg_timezone_names is that pg_open_tzfile()
has an inefficient way of identifying the canonical case of a zone name:
it basically re-descends the directory tree to the zone file. That's not
awful for an individual "SET timezone" operation, but it's pretty horrid
when we're inspecting every zone in the database. And it's pointless too
because we already know the canonical spelling, having just read it from
the filesystem. Fix by teaching pg_open_tzfile() to avoid the directory
search if it's not asked for the canonical name, and backfilling the
proper result in pg_tzenumerate_next().
In combination these changes seem to make the pg_timezone_names view
about 3x faster to read, for me. Since a scan of pg_timezone_names
has up to now been one of the slowest queries in the regression tests,
this should help some little bit for buildfarm cycle times.
Back-patch to all supported branches, not so much because it's likely
that users will care much about the view's performance as because
tracking changes in the upstream IANA timezone code is really painful
if we don't keep all the branches in sync.
Discussion: https://postgr.es/m/27962.1493671706@sss.pgh.pa.us
Due to a missing CommandCounterIncrement() call, parsing of a non-utility
command in an extension script would not see the effects of the immediately
preceding DDL command, unless that command's execution ends with
CommandCounterIncrement() internally ... which some do but many don't.
Report by Philippe Beaudoin, diagnosis by Julien Rouhaud.
Rather remarkably, this bug has evaded detection since extensions were
invented, so back-patch to all supported branches.
Discussion: https://postgr.es/m/2cf7941e-4e41-7714-3de8-37b1a8f74dff@free.fr
DST law changes in Chile, Haiti, and Mongolia. Historical corrections for
Ecuador, Kazakhstan, Liberia, and Spain.
The IANA crew continue their campaign to replace invented time zone
abbrevations with numeric GMT offsets. This update changes numerous zones
in South America, the Pacific and Indian oceans, and some Asian and Middle
Eastern zones. I kept these abbreviations in the tznames/ data files,
however, so that we will still accept them for input. (We may want to
start trimming those files someday, but I think we should wait for the
upstream dust to settle before deciding what to do.)
In passing, add MESZ (Mitteleuropaeische Sommerzeit) to the tznames lists;
since we accept MEZ (Mitteleuropaeische Zeit) it seems rather strange not
to take the other one. And fix some incorrect, or at least obsolete,
comments that certain abbreviations are not traceable to the IANA data.
Currently only provision for running the bin checks in a single step is
provided for. Now these tests can be run individually, as well as tests
in other locations (e.g. src.test/recover).
Also provide for suppressing unnecessary temp installs by setting the
NO_TEMP_INSTALL environment variable just as the Makefiles do.
Backpatch to 9.4.
zic no longer mishandles some transitions in January 2038 when it
attempts to work around Qt bug 53071. This fixes a bug affecting
Pacific/Tongatapu that was introduced in zic 2016e. localtime.c
now contains a workaround, useful when loading a file generated by
a buggy zic.
There are assorted cosmetic changes as well, notably relocation
of a bunch of #defines.
Currently, trying to validate a NO INHERIT constraint on the parent will
search for the constraint in child tables (where it is not supposed to
exist), wrongly causing a "constraint does not exist" error.
Amit Langote, per a report from Hans Buschmann.
Discussion: http://postgr.es/m/20170421184012.24362.19@wrigleys.postgresql.org
Logical decoding stores historical snapshots on disk, so that logical
decoding can restart without having to reconstruct a snapshot from
scratch (for which the resources are not guaranteed to be present
anymore). These serialized snapshots were also used when creating a
new slot via the walsender interface, which can export a "full"
snapshot (i.e. one that can read all tables, not just catalog ones).
The problem is that the serialized snapshots are only useful for
catalogs and not for normal user tables. Thus the use of such a
serialized snapshot could result in an inconsistent snapshot being
exported, which could lead to queries returning wrong data. This
would only happen if logical slots are created while another logical
slot already exists.
Author: Petr Jelinek
Reviewed-By: Andres Freund
Discussion: https://postgr.es/m/f37e975c-908f-858e-707f-058d3b1eb214@2ndquadrant.com
Backport: 9.4, where logical decoding was introduced.
Commit fa31b6f4e supposed that we didn't have to worry about that
anymore, but it seems that RHEL5 is like that, and that's still
a supported platform. Put back the prior coding under an #ifdef,
adding an explicit fcntl() to retain the desired CLOEXEC property.
Discussion: https://postgr.es/m/12307.1493325329@sss.pgh.pa.us
The logical decoding machinery already preserved all the required
catalog tuples, which is sufficient in the course of normal logical
decoding, but did not guarantee that non-catalog tuples were preserved
during computation of the initial snapshot when creating a slot over
the replication protocol.
This could cause a corrupted initial snapshot being exported. The
time window for issues is usually not terribly large, but on a busy
server it's perfectly possible to it hit it. Ongoing decoding is not
affected by this bug.
To avoid increased overhead for the SQL API, only retain additional
tuples when a logical slot is being created over the replication
protocol. To do so this commit changes the signature of
CreateInitDecodingContext(), but it seems unlikely that it's being
used in an extension, so that's probably ok.
In a drive-by fix, fix handling of
ReplicationSlotsComputeRequiredXmin's already_locked argument, which
should only apply to ProcArrayLock, not ReplicationSlotControlLock.
Reported-By: Erik Rijkers
Analyzed-By: Petr Jelinek
Author: Petr Jelinek, heavily editorialized by Andres Freund
Reviewed-By: Andres Freund
Discussion: https://postgr.es/m/9a897b86-46e1-9915-ee4c-da02e4ff6a95@2ndquadrant.com
Backport: 9.4, where logical decoding was introduced.
Although the postmaster doesn't currently create a self-pipe or any
latches, there's discussion of it doing so in future. It's also
conceivable that a shared_preload_libraries extension would try to
create such a thing in the postmaster process today. In that case
the self-pipe FDs would be inherited by forked child processes.
latch.c was entirely unprepared for such a case and could suffer an
assertion failure, or worse try to use the inherited pipe if somebody
called WaitLatch without having called InitializeLatchSupport in that
process. Make it keep track of whether InitializeLatchSupport has been
called in the *current* process, and do the right thing if state has
been inherited from a parent.
Apply FD_CLOEXEC to file descriptors created in latch.c (the self-pipe,
as well as epoll event sets). This ensures that child processes spawned
in backends, the archiver, etc cannot accidentally or intentionally mess
with these FDs. It also ensures that we end up with the right state
for the self-pipe in EXEC_BACKEND processes, which otherwise wouldn't
know to close the postmaster's self-pipe FDs.
Back-patch to 9.6, mainly to keep latch.c looking similar in all branches
it exists in.
Discussion: https://postgr.es/m/8322.1493240739@sss.pgh.pa.us
Previously, maybe_start_bgworker() would launch at most one bgworker
process per call, on the grounds that the postmaster might otherwise
neglect its other duties for too long. However, that seems overly
conservative, especially since bad effects only become obvious when
many hundreds of bgworkers need to be launched at once. On the other
side of the coin is that the existing logic could result in substantial
delay of bgworker launches, because ServerLoop isn't guaranteed to
iterate immediately after a signal arrives. (My attempt to fix that
by using pselect(2) encountered too many portability question marks,
and in any case could not help on platforms without pselect().)
One could also question the wisdom of using an O(N^2) processing
method if the system is intended to support so many bgworkers.
As a compromise, allow that function to launch up to 100 bgworkers
per call (and in consequence, rename it to maybe_start_bgworkers).
This will allow any normal parallel-query request for workers
to be satisfied immediately during sigusr1_handler, avoiding the
question of whether ServerLoop will be able to launch more promptly.
There is talk of rewriting the postmaster to use a WaitEventSet to
avoid the signal-response-delay problem, but I'd argue that this change
should be kept even after that happens (if it ever does).
Backpatch to 9.6 where parallel query was added. The issue exists
before that, but previous uses of bgworkers typically aren't as
sensitive to how quickly they get launched.
Discussion: https://postgr.es/m/4707.1493221358@sss.pgh.pa.us
This reverts commit b9515b6287.
Buildfarm results suggest that some platforms have versions of pselect(2)
that are not merely non-atomic, but flat out non-functional. Revert the
use-pselect patch to confirm this diagnosis (and exclude the no-SA_RESTART
patch as the source of trouble). If it's so, we should probably look into
blacklisting specific platforms that have broken pselect.
Discussion: https://postgr.es/m/9696.1493072081@sss.pgh.pa.us
Traditionally we've unblocked signals, called select(2), and then blocked
signals again. The code expects that the select() will be cancelled with
EINTR if an interrupt occurs; but there's a race condition, which is that
an already-pending signal will be delivered as soon as we unblock, and then
when we reach select() there will be nothing preventing it from waiting.
This can result in a long delay before we perform any action that
ServerLoop was supposed to have taken in response to the signal. As with
the somewhat-similar symptoms fixed by commit 893902085, the main practical
problem is slow launching of parallel workers. The window for trouble is
usually pretty short, corresponding to one iteration of ServerLoop; but
it's not negligible.
To fix, use pselect(2) in place of select(2) where available, as that's
designed to solve exactly this problem. Where not available, we continue
to use the old way, and are no worse off than before.
pselect(2) has been required by POSIX since about 2001, so most modern
platforms should have it. A bigger portability issue is that some
implementations are said to be non-atomic, ie pselect() isn't really
any different from unblock/select/reblock. Still, we're no worse off
than before on such a platform.
There is talk of rewriting the postmaster to use a WaitEventSet and
not do signal response work in signal handlers, at which point this
could be reverted, since we'd be using a self-pipe to solve the race
condition. But that's not happening before v11 at the earliest.
Back-patch to 9.6. The problem exists much further back, but the
worst symptom arises only in connection with parallel query, so it
does not seem worth taking any portability risks in older branches.
Discussion: https://postgr.es/m/9205.1492833041@sss.pgh.pa.us
The postmaster keeps signals blocked everywhere except while waiting
for something to happen in ServerLoop(). The code expects that the
select(2) will be cancelled with EINTR if an interrupt occurs; without
that, followup actions that should be performed by ServerLoop() itself
will be delayed. However, some platforms interpret the SA_RESTART
signal flag as meaning that they should restart rather than cancel
the select(2). Worse yet, some of them restart it with the original
timeout delay, meaning that a steady stream of signal interrupts can
prevent ServerLoop() from iterating at all if there are no incoming
connection requests.
Observable symptoms of this, on an affected platform such as HPUX 10,
include extremely slow parallel query startup (possibly as much as
30 seconds) and failure to update timestamps on the postmaster's sockets
and lockfiles when no new connections arrive for a long time.
We can fix this by running the postmaster's signal handlers without
SA_RESTART. That would be quite a scary change if the range of code
where signals are accepted weren't so tiny, but as it is, it seems
safe enough. (Note that postmaster children do, and must, reset all
the handlers before unblocking signals; so this change should not
affect any child process.)
There is talk of rewriting the postmaster to use a WaitEventSet and
not do signal response work in signal handlers, at which point it might
be appropriate to revert this patch. But that's not happening before
v11 at the earliest.
Back-patch to 9.6. The problem exists much further back, but the
worst symptom arises only in connection with parallel query, so it
does not seem worth taking any portability risks in older branches.
Discussion: https://postgr.es/m/9205.1492833041@sss.pgh.pa.us
This corner case didn't behave nicely at all: the postmaster would
(partially) update its state as though the process had started
successfully, and be quite confused thereafter. Fix it to act
like the worker had crashed, instead.
In passing, refactor so that do_start_bgworker contains all the
state-change logic for bgworker launch, rather than just some of it.
Back-patch as far as 9.4. 9.3 contains similar logic, but it's just
enough different that I don't feel comfortable applying the patch
without more study; and the use of bgworkers in 9.3 was so small
that it doesn't seem worth the extra work.
transam/parallel.c is still entirely unprepared for the possibility
of bgworker startup failure, but that seems like material for a
separate patch.
Discussion: https://postgr.es/m/4905.1492813727@sss.pgh.pa.us
This seems to be largely cosmetic, avoiding valgrind bleats and the
like. The uninitialized padding influences the CRC of the on-disk
entry, but because it's also used when verifying the CRC, that doesn't
cause spurious failures. Backpatch nonetheless.
It's a bit unfortunate that contrib/test_decoding/sql/replorigin.sql
doesn't exercise the checkpoint path, but checkpoints are fairly
expensive on weaker machines, and we'd have to stop/start for that to
be meaningful.
Author: Andres Freund
Discussion: https://postgr.es/m/20170422183123.w2jgiuxtts7qrqaq@alap3.anarazel.de
Backpatch: 9.5, where replication origins were introduced
ProcessTwoPhaseBuffer (formerly StandbyRecoverPreparedTransactions)
mixed up the parent and child XIDs when calling SubTransSetParent to
record the transactions' relationship in pg_subtrans.
Remarkably, analysis by Simon Riggs suggests that this doesn't lead to
visible problems (at least, not in non-Assert builds). That might
explain why we'd not noticed it before. Nonetheless, it's surely wrong.
This code was born broken, so back-patch to all supported branches.
Discussion: https://postgr.es/m/20110.1492905318@sss.pgh.pa.us
archive_command and restore_command need to refer to Windows paths, not
Msys virtual file system paths, as postgres is completely unaware of the
latter, so prefix them with the Windows path to the virtual file system
root. Clean psql output of carriage returns.
PostgresNode blithely ignored the exit status of pg_ctl, and in general
made no effort to be sure that the server was running when it should be.
This caused it to miss server crashes, which is a serious shortcoming
in a test scaffold. Make it complain if pg_ctl fails, and modify the
start and stop logic to complain if the server doesn't start, or doesn't
stop, when expected.
Also, have it turn off the "restart_after_crash" configuration parameter
in created clusters, as bitter experience has shown that leaving that on
can mask crashes too.
We might at some point need variant functions that allow for, eg,
server start failure to be expected. But no existing test case appears
to want that, and it surely shouldn't be the default behavior.
Note that this *will* break the buildfarm, as it will expose known
bugs that the previous testing failed to. I'm committing it despite
that, to verify that we get the expected failures in the buildfarm
not just in manual testing.
Back-patch into 9.6 where PostgresNode was introduced. (The 9.6
branch is not expected to show any failures.)
Discussion: https://postgr.es/m/21432.1492886428@sss.pgh.pa.us
Although the documentation for append_conf said clearly that it didn't
add a newline, many test authors seem to have forgotten that ... or maybe
they just consulted the example at the top of the POD documentation,
which clearly shows adding a config entry without bothering to add a
trailing newline. The worst part of that is that it works, as long as
you don't do it more than once, since the backend isn't picky about
whether config files end with newlines. So there's not a strong forcing
function reminding test authors not to do it like that. Upshot is that
this is a terribly fragile way to go about things, and there's at least
one existing test case that is demonstrably broken and not testing what
it thinks it is.
Let's just make append_conf append a newline, instead; that is clearly
way safer than the old definition.
I also cleaned up a few call sites that were unnecessarily ugly.
(I left things alone in places where it's plausible that additional
config lines would need to be added someday.)
Back-patch the change in append_conf itself to 9.6 where it was added,
as having a definitional inconsistency between branches would obviously
be pretty hazardous for back-patching TAP tests. The other changes are
just cosmetic and don't need to be back-patched.
Discussion: https://postgr.es/m/19751.1492892376@sss.pgh.pa.us
The POSIX standard does not say that the success return value for
fcntl(F_SETFD) and fcntl(F_SETFL) is zero; it says only that it's not -1.
We had several calls that were making the stronger assumption. Adjust
them to test specifically for -1 for strict spec compliance.
The standard further leaves open the possibility that the O_NONBLOCK
flag bit is not the only active one in F_SETFL's argument. Formally,
therefore, one ought to get the current flags with F_GETFL and store
them back with only the O_NONBLOCK bit changed when trying to change
the nonblock state. In port/noblock.c, we were doing the full pushup
in pg_set_block but not in pg_set_noblock, which is just weird. Make
both of them do it properly, since they have little business making
any assumptions about the socket they're handed. The other places
where we're issuing F_SETFL are working with FDs we just got from
pipe(2), so it's reasonable to assume the FDs' properties are all
default, so I didn't bother adding F_GETFL steps there.
Also, while pg_set_block deserves some points for trying to do things
right, somebody had decided that it'd be even better to cast fcntl's
third argument to "long". Which is completely loony, because POSIX
clearly says the third argument for an F_SETFL call is "int".
Given the lack of field complaints, these missteps apparently are not
of significance on any common platforms. But they're still wrong,
so back-patch to all supported branches.
Discussion: https://postgr.es/m/30882.1492800880@sss.pgh.pa.us
We were applying the use_physical_tlist optimization to all relation
scan plans, even those implemented by custom scan providers. However,
that's a bad idea for a couple of reasons. The custom provider might
be unable to provide columns that it hadn't expected to be asked for
(for example, the custom scan might depend on an index-only scan).
Even more to the point, there's no good reason to suppose that this
"optimization" is a win for a custom scan; whatever the custom provider
is doing is likely not based on simply returning physical heap tuples.
(As a counterexample, if the custom scan is an interface to a column store,
demanding all columns would be a huge loss.) If it is a win, the custom
provider could make that decision for itself and insert a suitable
pathtarget into the path, anyway.
Per discussion with Dmitry Ivanov. Back-patch to 9.5 where custom scan
support was introduced. The argument that the custom provider can adjust
the behavior by changing the pathtarget only applies to 9.6+, but on
balance it seems more likely that use_physical_tlist will hurt custom
scans than help them.
Discussion: https://postgr.es/m/e29ddd30-8ef9-4da5-a50b-2bb7b8c7198d@postgrespro.ru
In standard non-Windows builds, there's no particular reason to care what
address the kernel chooses to map the shared memory segment at. However,
when building with EXEC_BACKEND, there's a risk that the chosen address
won't be available in all child processes. Linux with ASLR enabled (which
it is by default) seems particularly at risk because it puts shmem segments
into the same area where it maps shared libraries. We can work around
that by specifying a mapping address that's outside the range where
shared libraries could get mapped. On x86_64 Linux, 0x7e0000000000
seems to work well.
This is only meant for testing/debugging purposes, so it doesn't seem
necessary to go as far as providing a GUC (or any user-visible
documentation, though we might change that later). Instead, it's just
controlled by setting an environment variable PG_SHMEM_ADDR to the
desired attach address.
Back-patch to all supported branches, since the point here is to
remove intermittent buildfarm failures on EXEC_BACKEND animals.
Owners of affected animals will need to add a suitable setting of
PG_SHMEM_ADDR to their build_env configuration.
Discussion: https://postgr.es/m/7036.1492231361@sss.pgh.pa.us
This back-patches commit 32470825d3
into 9.6, primarily to make buildfarm member culicidae happy.
Unlike the HEAD patch, avoid changing the existing API of
CreateParallelContext; instead we just switch to using
CreateParallelContextForExternalFunction, even for core functions.
Petr Jelinek, with a bunch of basically-cosmetic adjustments by me
Discussion: https://postgr.es/m/548f9c1d-eafa-e3fa-9da8-f0cc2f654e60@2ndquadrant.com
regexport.c thought it could just ignore LACON arcs, but the correct
behavior is to treat them as satisfiable while consuming zero input
(rather reminiscently of commit 9f1e642d5). Otherwise, the emitted
simplified-NFA representation may contain no paths leading from initial
to final state, which unsurprisingly confuses pg_trgm, as seen in
bug #14623 from Jeff Janes.
Since regexport's output representation has no concept of an arc that
consumes zero input, recurse internally to find the next normal arc(s)
after any LACON transitions. We'd be forced into changing that
representation if a LACON could be the last arc reaching the final
state, but fortunately the regex library never builds NFAs with such
a configuration, so there always is a next normal arc.
Back-patch to 9.3 where this logic was introduced.
Discussion: https://postgr.es/m/20170413180503.25948.94871@wrigleys.postgresql.org
This extends the castNode() notation introduced by commit 5bcab1114 to
provide, in one step, extraction of a list cell's pointer and coercion to
a concrete node type. For example, "lfirst_node(Foo, lc)" is the same
as "castNode(Foo, lfirst(lc))". Almost half of the uses of castNode
that have appeared so far include a list extraction call, so this is
pretty widely useful, and it saves a few more keystrokes compared to the
old way.
As with the previous patch, back-patch the addition of these macros to
pg_list.h, so that the notation will be available when back-patching.
Patch by me, after an idea of Andrew Gierth's.
Discussion: https://postgr.es/m/14197.1491841216@sss.pgh.pa.us
As reported by Sean Johnston in bug #14614, since 9.6 the planner can fail
due to trying to look up the referent of a Var with varno 0. This happens
because we generate such Vars in generate_append_tlist, for lack of any
better way to describe the output of a SetOp node. In typical situations
nothing really cares about that, but given nested set-operation queries
we will call estimate_num_groups on the output of the subquery, and that
wants to know what a Var actually refers to. That logic used to look at
subquery->targetList, but in commit 3fc6e2d7f I'd switched it to look at
subroot->processed_tlist, ie the actual output of the subquery plan not the
parser's idea of the result. It seemed like a good idea at the time :-(.
As a band-aid fix, change it back.
Really we ought to have an honest way of naming the outputs of SetOp steps,
which suggests that it'd be a good idea for the parser to emit an RTE
corresponding to each one. But that's a task for another day, and it
certainly wouldn't yield a back-patchable fix.
Report: https://postgr.es/m/20170407115808.25934.51866@wrigleys.postgresql.org
HandleFunctionRequest() is no longer responsible for reading the protocol
message from the client, since commit 2b3a8b20c2. Fix the outdated
comments.
HandleFunctionRequest() now always returns 0, because the code that used
to return EOF was moved in 2b3a8b20c2. Therefore, the caller no longer
needs to check the return value.
Reported by Andres Freund. Backpatch to all supported versions, even though
this doesn't have any user-visible effect, to make backporting future
patches in this area easier.
Discussion: https://www.postgresql.org/message-id/20170405010525.rt5azbya5fkbhvrx@alap3.anarazel.de
When using integer timestamps, the interval-comparison functions tried
to compute the overall magnitude of an interval as an int64 number of
microseconds. As reported by Frazer McLean, this overflows for intervals
exceeding about 296000 years, which is bad since we nominally allow
intervals many times larger than that. That results in wrong comparison
results, and possibly in corrupted btree indexes for columns containing
such large interval values.
To fix, compute the magnitude as int128 instead. Although some compilers
have native support for int128 calculations, many don't, so create our
own support functions that can do 128-bit addition and multiplication
if the compiler support isn't there. These support functions are designed
with an eye to allowing the int128 code paths in numeric.c to be rewritten
for use on all platforms, although this patch doesn't do that, or even
provide all the int128 primitives that will be needed for it.
Back-patch as far as 9.4. Earlier releases did not guard against overflow
of interval values at all (commit 146604ec4 fixed that), so it seems not
very exciting to worry about overly-large intervals for them.
Before 9.6, we did not assume that unreferenced "static inline" functions
would not draw compiler warnings, so omit functions not directly referenced
by timestamp.c, the only present consumer of int128.h. (We could have
omitted these functions in HEAD too, but since they were written and
debugged on the way to the present patch, and they look likely to be needed
by numeric.c, let's keep them in HEAD.) I did not bother to try to prevent
such warnings in a --disable-integer-datetimes build, though.
Before 9.5, configure will never define HAVE_INT128, so the part of
int128.h that exploits a native int128 implementation is dead code in the
9.4 branch. I didn't bother to remove it, thinking that keeping the file
looking similar in different branches is more useful.
In HEAD only, add a simple test harness for int128.h in src/tools/.
In back branches, this does not change the float-timestamps code path.
That's not subject to the same kind of overflow risk, since it computes
the interval magnitude as float8. (No doubt, when this code was originally
written, overflow was disregarded for exactly that reason.) There is a
precision hazard instead :-(, but we'll avert our eyes from that question,
since no complaints have been reported and that code's deprecated anyway.
Kyotaro Horiguchi and Tom Lane
Discussion: https://postgr.es/m/1490104629.422698.918452336.26FA96B7@webmail.messagingengine.com
This backpatches 51e26c9 and 7220c7b, including both documentation
updates clarifying the checkpoints at the beginning of base backups and
the messages in verbose and progress mdoe of pg_basebackup.
Author: Michael Banck
Discussion: https://postgr.es/m/21444.1488142764%40sss.pgh.pa.us
Commit 45be99f8cd removed GatherPath's
num_workers field, but this is entirely bogus. Normally, a path's
parallel_workers flag is supposed to indicate the number of workers
that it wants, and should be 0 for a non-partial path. In that
commit, I mistakenly thought that GatherPath could also use that field
to indicate the number of workers that it would try to start, but
that's disastrous, because then it can propagate up to higher nodes in
the plan tree, which will then get incorrect rowcounts because the
parallel_workers flag is involved in computing those values. Repair
by putting the separate field back.
Report by Tomas Vondra. Patch by me, reviewed by Amit Kapila.
Discussion: http://postgr.es/m/f91b4a44-f739-04bd-c4b6-f135bd643669@2ndquadrant.com
On EXEC_BACKEND builds, this can fail if ASLR is in use.
Backpatch to 9.5. On master, completely remove the bgw_main field
completely, since there is no situation in which it is safe for an
EXEC_BACKEND build. On 9.6 and 9.5, leave the field intact to avoid
breaking things for third-party code that doesn't care about working
under EXEC_BACKEND. Prior to 9.5, there are no in-core bgworker
entrypoints.
Petr Jelinek, reviewed by me.
Discussion: http://postgr.es/m/09d8ad33-4287-a09b-a77f-77f8761adb5e@2ndquadrant.com
We were assigning values near 255 through "char *" pointers. On machines
where char is signed, that's not entirely kosher, and it's reasonable
for compilers to warn about it.
A better solution would be to change the pointer type to "unsigned char *",
but that would be vastly more invasive. For the moment, let's just apply
this simple backpatchable solution.
Aleksander Alekseev
Discussion: https://postgr.es/m/20170220141239.GD12278@e733.localdomain
Discussion: https://postgr.es/m/2839.1490714708@sss.pgh.pa.us
The compiler is entitled to store a char[] local variable with no
particular alignment requirement. Our RADIUS code cavalierly took such
a local variable and cast its address to a struct type that does have
alignment requirements. On an alignment-picky machine this would lead
to bus errors. To fix, declare the local variable honestly, and then
cast its address to char * for use in the I/O calls.
Given the lack of field complaints, there must be very few if any
people affected; but nonetheless this is a clear portability issue,
so back-patch to all supported branches.
Noted while looking at a Coverity complaint in the same code.
Commit 7aea8e4f2d allowed a parallel
plan to be generated when for a RETURN QUERY or RETURN QUERY EXECUTE
statement in a PL/pgsql block, but that's a bad idea because plplgsql
asks the executor for 50 rows at a time. That means that we'll always
be running serially a plan that was intended for parallel execution,
which is not a good idea. Fix by not requesting a parallel plan from
the outset.
Per discussion, back-patch to 9.6. There is a slight risk that, due
to optimizer error, somebody could have a case where the parallel plan
executed serially is actually faster than the supposedly-best serial
plan, but the consensus seems to be that that's not sufficient
justification for leaving 9.6 unpatched.
Discussion: http://postgr.es/m/CA+TgmoZ_ZuH+auEeeWnmtorPsgc_SmP+XWbDsJ+cWvWBSjNwDQ@mail.gmail.com
Discussion: http://postgr.es/m/CA+TgmobXEhvHbJtWDuPZM9bVSLiTj-kShxQJ2uM5GPDze9fRYA@mail.gmail.com
The bug is that prior to --rate doCustom was always disconnect/reconnect
without exiting, but with rate it returns if it has to wait. However threadRun
test whether there is a connection before recalling doCustom, so it was never
called.
Bug is not existed in head branch because of refactoring at
12788ae49e, patch only 9.6
Author: Fabien Coelho
Reviewed-by: me
https://commitfest.postgresql.org/13/970/
Assert-enabled build crashes but without asserts it works by wrong way:
it may not reset forcing full page write and preventing from starting
exclusive backup with the same name as cancelled.
Patch replaces pair of booleans
nonexclusive_backup_running/exclusive_backup_running to single enum to
correctly describe backup state.
Backpatch to 9.6 where bug was introduced
Reported-by: David Steele
Authors: Michael Paquier, David Steele
Reviewed-by: Anastasia Lubennikova
https://commitfest.postgresql.org/13/1068/
