There are some sections which could be improved
and work to do so is on going. The work will be
covered via 'X-MFC-WITH' commits.
Obtained from: OpenBSD
Differential Revision: https://reviews.freebsd.org/D34759
(cherry picked from commit 4b7f35db44)
Mark Milliard has detected a case of undefined behavior with the LLVM
UBSAN. The mandoc program called qsort with a==NULL and n==0, which is
allowed by the POSIX standard. The qsort() in FreeBSD did not attempt
to perform any accesses using the passed pointer for n==0, but it did
add an offset to the pointer value, which is undefined behavior in
case of a NULL pointer. This operation has no adverse effects on any
achitecture supported by FreeBSD, but could be caught in more strict
environments.
After some discussion in the freebsd-current mail list, it was
concluded that the case of a==NULL and n!=0 should still be caught by
UBSAN (or cause a program abort due to an illegal access) in order to
not hide errors in programs incorrectly invoking qsort().
Only the the case of a==NULL and n==0 should be fixed to not perform
the undefined operation on a NULL pointer.
This commit makes qsort() exit before reaching the point of
potentially undefined behvior for the case n==0, but does not test
the value of a, since the result will not depend on whether this
pointer is NULL or an actual pointer to an array if n==0.
The issue found by Mark Milliard in the whatis command has been
reported to the upstream (OpenBSD) and has already been patched
there.
(cherry picked from commit d106f982a5)
Clang 13 produces the following warning for this function:
lib/libc/stdlib/merge.c:137:41: error: performing pointer subtraction with a null pointer has undefined behavior [-Werror,-Wnull-pointer-subtraction]
if (!(size % ISIZE) && !(((char *)base - (char *)0) % ISIZE))
^ ~~~~~~~~~
This is meant to check whether the size and base parameters are aligned
to the size of an int, so use our __is_aligned() macro instead.
Also remove the comment that indicated this "stupid subtraction" was
done to pacify some ancient and unknown Cray compiler, and which has
been there since the BSD 4.4 Lite Lib Sources were imported.
(cherry picked from commit 4e5d32a445)
Before this patch there was a chance for thread that called rand(3)
slightly later to see rand3_state already allocated, but not yet
initialized. While this API is not expected to be thread-safe, it
is not expected to crash. ztest on 64-thread system reproduced it
reliably for me.
Submitted by: avg@
MFC after: 1 month
(cherry picked from commit 3a57f08b50)
This causes problems when using ASAN with a runtime older than 12.0 since
the intercept does not expect qsort() to call itself using an interposable
function call. This results in infinite recursion and stack exhaustion
when a binary compiled with -fsanitize=address calls qsort.
See also https://bugs.llvm.org/show_bug.cgi?id=46832 and
https://reviews.llvm.org/D84509 (ASAN runtime patch).
To prevent this problem, this patch uses a static helper function
for the actual qsort() implementation. This prevents interposition and
allows for direct calls. As a nice side-effect, we can also move the
qsort_s checks to the top-level function and out of the recursive calls.
Reviewed By: kib
Differential Revision: https://reviews.freebsd.org/D28133
(cherry picked from commit cbcfe28f9d)
This file has other questionable code and "optimizations" (such as copying
one int at a time) that are probably no longer useful, so it might make
sense to replace it with a different implementation at some point.
Reviewed By: jhb
Differential Revision: https://reviews.freebsd.org/D28134
Define a non-const static char EMSG[] = "" to avoid having to add
__DECONST() to all uses of EMSG. Also make current_dash a const char *
to fix this warning.
- varios "new sentence, new line" warnings
- varios "sections out of conventional order" warnings
- varios "unusual Xr order" warnings
- varios "missing section argument" warnings
- varios "no blank before trailing delimiter" warnings
- varios "normalizing date format" warnings
MFC after: 1 month
- Hide ptsname_r under __BSD_VISIBLE for now as the specification
is not finalized at this time.
- Keep Symbol.map sorted.
- Avoid the interposing of ptsname_r(3) from an user application
from breaking ptsname(3) by making the implementation a static
method and call the static function from ptsname(3) instead.
Reported by: kib
Reviewed by: kib, jilles
MFC after: 2 weeks
Differential Revision: https://reviews.freebsd.org/D26845
MK_MALLOC_PRODUCTION option on -CURRENT.
Also, for the sake of backwards compatibility, support the old way of
enabling 'production malloc', e.g. by adding a define in make.conf(5).
MFC after: 1 week
X-MFC-With: r365371
For historical reasons, defining MALLOC_PRODUCTION in /etc/make.conf has
been used to turn off potentially expensive debug checks and statistics
gathering in the implementation of malloc(3).
It seems more consistent to turn this into a regular src.conf(5) option,
e.g. WITH_MALLOC_PRODUCTION / WITHOUT_MALLOC_PRODUCTION. This can then
be toggled similar to any other source build option, and turned on or
off by default for e.g. stable branches.
Reviewed by: imp, #manpages
MFC after: 1 week
Differential Revision: https://reviews.freebsd.org/D26337
Previously this was counting the amount of spare room at the start of
the buffer that the string needed to move forward and passing that as
the number of bytes to copy to memmove rather than the length of the
string to be copied.
In the strfmon test in the test suite this caused the memmove to
overflow the allocated buffer by one byte which CHERI caught.
Reported by: CHERI
Reviewed by: kevans
Obtained from: CheriBSD
MFC after: 1 week
Sponsored by: DARPA
Differential Revision: https://reviews.freebsd.org/D26280
Revert r354606 to restore r354605.
Apply one line from jemalloc commit d01b425e5d1e1 in hash_x86_128()
to fix the build with gcc, which only allows a fallthrough attribute
to appear before a case or default label.
Submitted by: jasone in r354605
Discussed with: jasone
Reviewed by: bdrewery
MFC after: never, due to gcc 4.2.1
Relnotes: yes
Sponsored by: Dell EMC Isilon
Differential Revision: https://reviews.freebsd.org/D24522
These functions first appeared in the First Edition of Unix (or earlier in the
pdp-7 version). Just claim 1st Edition for all this. The pdp-7 code is too
fragmented at this point to extend history that far back.
realpath(3) is used a lot e.g., by clang and is a major source of getcwd
and fstatat calls. This can be done more efficiently in the kernel.
This works by performing a regular lookup while saving the name and found
parent directory. If the terminal vnode is a directory we can resolve it using
usual means. Otherwise we can use the name saved by lookup and resolve the
parent.
See the review for sample syscall counts.
Reviewed by: kib
Differential Revision: https://reviews.freebsd.org/D23574
rand(3)'s standard C API is extremely limiting, but we can do better
than the historical 32-bit state Park-Miller LCG we've shipped since
2001: r73156.
The justification provided at the time for not using random(3) was that
rand_r(3) could not be made to use the same algorithm. That is still
true. However, the irrelevance of rand_r(3) is increasingly obvious.
Since that time, POSIX has marked the interface obsolescent. rand_r(3)
never became part of the standard C library. If not for API
compatibility reasons, I would just remove rand_r(3) entirely.
So, I do not believe it is a problem for rand_r(3) and rand(3) to
diverge.
The 12 ABI is maintained with compatibility definitions, but this
revision does subtly change the API of rand(3). The sequences of
pseudorandom numbers produced in programs built against new versions of
libc will differ from programs built against prior versions of libc.
Reviewed by: kevans, markm
MFC after: no
Relnotes: yes
Differential Revision: https://reviews.freebsd.org/D23290
The existing APIs simply pass the implicit global state to the _r variants.
No functional change.
Note that these routines are not exported from libc and are not intended to be
exported. If someone wished to export them from libc (which I would
discourage), they should first be modified to match the inconsistent parameter
type / order of the glibc public interfaces of the same names.
I know Ravi will ask, so: the eventual goal of this series is to replace
rand(3) with the implementation from random(3) (D23290). However, I'd like to
wait a bit longer on that one to see if more feedback emerges.
Reviewed by: kevans, markm
Differential Revision: https://reviews.freebsd.org/D23289
to port software written for Linux variant of qsort_r(3).
Reviewed by: kib, arichardson
MFC after: 2 weeks
Relnotes: yes
Sponsored by: DARPA
Differential Revision: https://reviews.freebsd.org/D23174
It serves no useful purpose and wasn't as popular as its equally meritless
cousin, srandomdev(3).
Setting aside the problems with rand(3) in general, the problem with this
interface is that the seed isn't shared with the caller (other than by
attacking the output of the generator, which is trivial, but not a hallmark of
pleasant API design). The (arguable) utility of rand(3) or random(3) is as a
semi-fast simulation generator which produces consistent results from a given
seed. These are mutually at odd. Furthermore, sometimes people got the
mistaken impression that a high quality random seed meant a weak generator like
rand(3) or random(3) could be used for things like cryptographic key
generation. This is absolutely not so.
The API was never part of a standard and was not widely used in tree. Existing
in-tree uses have all been removed.
Possible replacement in out of tree codebases:
char buf[3];
time_t t;
time(t);
strftime(buf, sizeof(buf), "%S", gmtime(&t));
srand(atoi(buf));
Relnotes: yes
o Remove All Rights Reserved from my notices
o imp@FreeBSD.org everywhere
o regularize punctiation, eliminate date ranges
o Make sure that it's clear that I don't claim All Rights reserved by listing
All Rights Reserved on same line as other copyright holders (but not
me). Other such holders are also listed last where it's clear.
