This extends the strcspn() unit tests to catch mistakes in the
implementation that only appear when a mismatch occurs in a certain
position of the string against a certain position of the set.
See also: 52d4a4d4e0
Sponsored by: The FreeBSD Foundation
Approved by: imp
MFC after: 3 days
Differential Revision: https://reviews.freebsd.org/D41821
When memcmp(a, b, len) (or equally, bcmp) is called with a phony length
such that a + len < a, the code would malfunction and not compare the
two buffers correctly. While such arguments are illegal (buffers do not
wrap around the end of the address space), it is neverthless conceivable
that people try things like memcmp(a, b, SIZE_MAX) to compare a and b
until the first mismatch, in the knowledge that such a mismatch exists,
expecting memcmp() to stop comparing somewhere around the mismatch.
While memcmp() is usually written to confirm to this assumption, no
version of ISO/IEC 9899 guarantees this behaviour (in contrast to
memchr() for which it is).
Neverthless it appears sensible to at least not grossly misbehave on
phony lengths. This change hardens memcmp() against this case by
comparing at least until the end of the address space if a + len
overflows a 64 bit integer.
Sponsored by: The FreeBSD Foundation
Approved by: mjg (blanket, via IRC)
See also: b2618b651b
MFC after: 1 week
When a string is matched against a set of 17--32 characters, each chunk
of the string is matched first against the first 16 characters of the
set and then against the remaining characters. We also check at the
same time if the string has a nul byte in the current chunk, terminating
the search if it does.
Due to misconceived logic, the order of checks was "first half of set,
nul byte, second half of set", meaning that a match with the second half
of the set was ignored when the string ended in the same 16 bytes.
Reverse the order of checks to fix this problem.
Sponsored by: The FreeBSD Foundation
Approved by: mjg (blanket, via IRC)
MFC after: 1 week
MFC to: stable/14
When memchr(buf, c, len) is called with a phony len (say, SIZE_MAX),
buf + len overflows and we have buf + len < buf. This confuses the
implementation and makes it return incorrect results. Neverthless we
must support this case as memchr() is guaranteed to work even with
phony buffer lengths, as long as a match is found before the buffer
actually ends.
Sponsored by: The FreeBSD Foundation
Reported by: yuri, des
Tested by: des
Approved by: mjg (blanket, via IRC)
MFC after: 1 week
MFC to: stable/14
PR: 273652
Now that we have an optimised memchr(3), we can use it to implement
strnlen(3) with better perofrmance.
Sponsored by: The FreeBSD Foundation
Approved by: mjg
MFC after: 1 week
MFC to: stable/14
Differential Revision: https://reviews.freebsd.org/D41598
This is conceptually similar to strchr(3), but there are
slight changes to account for the buffer having an explicit
buffer length.
Sponsored by: The FreeBSD Foundation
Approved by: mjg
MFC after: 1 week
MFC to: stable/14
Differential Revision: https://reviews.freebsd.org/D41598
This is conceptually very similar to the strcspn(3) implementations
from D41557, but we can't do the fast paths the same way.
Sponsored by: The FreeBSD Foundation
Approved by: mjg
MFC after: 1 week
MFC to: stable/14
Differential Revision: https://reviews.freebsd.org/D41567
To cover the new optimised amd64 strspn(3) SIMD implementation, extend
the previously written strcspn(3) unit test to also cover strspn(3).
Sponsored by: The FreeBSD Foundation
Approved by: mjg
MFC after: 1 week
MFC to: stable/14
Differential Revision: https://reviews.freebsd.org/D41567
We currently use the NetBSD test suite to cover strcspn(3). It only
contains a very rudimentary test of this function. This all new set
of unit tests for the FreeBSD test suite should cover many more edge
cases relating to alignment issues.
Sponsored by: The FreeBSD Foundation
Approved by: mjg
MFC after: 1 week
MFC to: stable/14
Differential Revision: https://reviews.freebsd.org/D41557
This changeset adds both a scalar and an x86-64-v2 implementation
of the strcspn(3) function to libc. A baseline implementation does not
appear to be feasible given the requirements of the function.
The scalar implementation is similar to the generic libc implementation,
but expands the bit set into a byte set to reduce latency, improving
performance. This approach could probably be backported to the generic
C version to benefit other platforms.
The x86-64-v2 implementation is built around the infamous pcmpistri
instruction. An alternative implementation based on the Muła/Langdale
algorithm [1] was prototyped, but performed worse than the pcmpistri
approach except for sets of more than 16 characters with long input
strings.
All implementations provide special cases for the empty set (reduces to
strlen as well as single-character sets (reduces to strchr). The
x86-64-v2 kernel falls back to the scalar implementation for sets of
more than 32 characters. This limit could be raised by additional
multiples of 16 through the use of additional pcmpistri code paths, but
I consider this case to be too rare to be of importance.
[1]: http://0x80.pl/articles/simd-byte-lookup.html
Sponsored by: The FreeBSD Foundation
Approved by: mjg
MFC after: 1 week
MFC to: stable/14
Differential Revision: https://reviews.freebsd.org/D41557
This adds test cases for %wN and %wfN to the printf(3) and scanf(3) tests.
While here, fix a few nits in the N2630 test cases.
Reviewed by: imp
Differential Revision: https://reviews.freebsd.org/D41743
This adds specific width length modifiers in the form of wN and wfN (where N is 8, 16, 32, or 64) which allow printing intN_t and int_fastN_t without resorting to casts or PRI macros.
Reviewed by: imp, emaste
Differential Revision: https://reviews.freebsd.org/D41725
LIBCSRCDIR is defined in bsd.libnames.mk, which is read in later in the
Makefile than the line:
.if exists(${LIBCSRCDIR}/${MACHINE_ARCH})
so we test to see if /${MARCHIN_ARCH} exists which it usually doesn't
(but did for me since I mounted 13.2R SD image there). Move to defining
our own LIBC_SRCTOP in terms of SRCTOP to treat these uniformily.
Sponsored by: Netflix
Reviewed by: sjg
Differential Revision: https://reviews.freebsd.org/D41661
With the new simd-dispatch framework documented in simd(7),
add cross-references to the new man pages to appropriate places.
Sponsored by: The FreeBSD Foundation
Approved by: emaste
MFC to: stable/14
MFC after: 3 days
Differential Revision: https://reviews.freebsd.org/D41697
While here, also update a mention of ANSI C.
Sponsored by: Klara, Inc.
Reviewed by: kevans, markj
Differential Revision: https://reviews.freebsd.org/D41686
This will enable alternative mallocs to be included in the tree and
selected by setting LIBC_MALLOC. As there is only one today (jemalloc)
this option does nothing, but we expect to add other implementations
in the future. This will also reduce diffs to CheriBSD.
Reviewed by: emaste
Differential Revision: https://reviews.freebsd.org/D41660
strverscmp(3) and versionsort(3) where first released in 13.2
PR: 273401
Reviewed by: kib
MFC after: 3 days
Differential Revision: https://reviews.freebsd.org/D41617
This adds formatted input/output of binary integer numbers to the printf(), scanf(), and strtol() families, including their wide-character counterparts.
Reviewed by: imp, emaste
Differential Revision: https://reviews.freebsd.org/D41511
When the buffer is immediately preceeded by the character we
are looking for and begins with one higher than that character,
and the buffer is misaligned, a match was errorneously detected
in the first character. Fix this by changing the way we prevent
matches before the buffer from being detected: instead of
removing the corresponding bit from the 0x80..80 mask, set the
LSB of bytes before the buffer after xoring with the character we
look for.
The bug only affects amd64 with ARCHLEVEL=scalar (cf. simd(7)).
The change comes at a 2% performance impact for short strings
if ARCHLEVEL is set to scalar. The default configuration is not
affected.
os: FreeBSD
arch: amd64
cpu: 11th Gen Intel(R) Core(TM) i7-1165G7 @ 2.80GHz
│ strchrnul.scalar.0.out │ strchrnul.scalar.2.out │
│ sec/op │ sec/op vs base │
Short 57.89µ ± 2% 59.08µ ± 1% +2.07% (p=0.030 n=20)
Mid 19.24µ ± 0% 19.73µ ± 0% +2.53% (p=0.000 n=20)
Long 11.03µ ± 0% 11.03µ ± 0% ~ (p=0.547 n=20)
geomean 23.07µ 23.43µ +1.53%
│ strchrnul.scalar.0.out │ strchrnul.scalar.2.out │
│ B/s │ B/s vs base │
Short 2.011Gi ± 2% 1.970Gi ± 1% -2.02% (p=0.030 n=20)
Mid 6.049Gi ± 0% 5.900Gi ± 0% -2.47% (p=0.000 n=20)
Long 10.56Gi ± 0% 10.56Gi ± 0% ~ (p=0.547 n=20)
geomean 5.045Gi 4.969Gi -1.50%
MFC to: stable/14
MFC after: 3 days
Approved by: mjg (blanket, via IRC)
Sponsored by: The FreeBSD Foundation
Move the timerfd impelemntation from linux compat code to sys/kern. Use
it to implement the new system calls for timerfd. Add a hook to kern_tc
to allow timerfd to know when the system time has stepped. Add kqueue
support to timerfd. Adjust a few names to be less Linux centric.
RelNotes: YES
Reviewed by: markj (on irc), imp, kib (with reservations), jhb (slack)
Differential Revision: https://reviews.freebsd.org/D38459
Right now we have to zero-initialize most fields in the varius callers,
but this is a little error prone. Simplify it by zeroing it out upon
allocation instead, drop the other redundant initialization.
Reviewed by: markj
Sponsored by: Klara, Inc.
Differential Revision: https://reviews.freebsd.org/D41546
In 693f88c9da ("iconv_std: complete the //IGNORE support"), we
more completely implemented //IGNORE, which changed the semantics of
ci_discard_ilseq. DISCARD_ILSEQ semantics are supposed to match
//IGNORE, so we really can't do much about that particular
incompatibility. This broke c*rtomb and mbrtoc* handling of invalid
sequences, but it turns out they don't want DISCARD_ILSEQ semantics at
all; they really want the subset that we call
_CITRUS_ICONV_F_HIDE_INVALID.
This restores the exact flow in iconv_std to precisely how it happened
prior to 693f88c9da.
PR: 265871
Fixes: 693f88c9da ("iconv_std: complete the //IGNORE support")
Sponsored by: Klara, Inc.
Differential Revision: https://reviews.freebsd.org/D41513
This is an attempt at clean-room implementation of the Linux'
membarrier(2) syscall. For documentation, you would need to read
both membarrier(2) Linux man page, the comments in Linux
kernel/sched/membarrier.c implementation and possibly look at
actual uses.
Sponsored by: The FreeBSD Foundation
MFC after: 1 week
Differential revision: https://reviews.freebsd.org/D32360
This changeset adds a baseline implementation of memcmp and bcmp
for amd64. The same code is used for both functions with conditional
code were the behaviour differs (we need more precise output for the
memcmp case).
FreeBSD documents that memcmp returns the difference between the
mismatching characters. Slightly faster code would be possible could
we relax this requirement to the ISO/IEC 9899:1999 requirement of
merely returning a negative/positive integer or zero.
Performance is better than bionic and glibc, except for long strings
were the two are 13% faster. This could be because they use SSE4
ptest which we cannot use in a baseline kernel.
Sponsored by: The FreeBSD Foundation
Approved by: mjg
Differential Revision: https://reviews.freebsd.org/D41442
This commit adds a baseline implementation of stpcpy(3) for amd64.
It performs quite well in comparison to the previous scalar implementation
as well as agains bionic and glibc (though glibc is faster for very long
strings). Fiddle with the Makefile to also have strcpy(3) call into the
optimised stpcpy(3) code, fixing an oversight from D9841.
Sponsored by: The FreeBSD Foundation
Reviewed by: imp ngie emaste
Approved by: mjg kib
Fixes: D9841
Differential Revision: https://reviews.freebsd.org/D41349
pthread_getname_np needs to be provided by libc in order to import
jemalloc 5.3.0.
A stub implementation for libc pthread_getname_np() is added for
_pthread_stubs.c, which always reports empty name for the main thread.
Internal _pthread_getname_np() is not exported, but provided for libc
own use.
Reviewed by: kib
MFC after: 1 week
Differential Revision: https://reviews.freebsd.org/D41461
Create a stdlib/malloc to hold the definition of the malloc interface
(e.g., the Symbol.map file) and make jemalloc a subdirectory. This will
make it easier to integrate alternative allocators such as snmalloc
while making it clear that the current jemalloc symbols are the FreeBSD
API/ABI (for better or worse).
Suggested by: jrtc27
Reviewed by: jrtc27, emaste
Sponsored by: DARPA
Differential Revision: https://reviews.freebsd.org/D41457
All jemalloc sources are in contrib so don't look for them in the
jemalloc subdirectory.
Reviewed by: jrtc27, emaste
Sponsored by: DARPA
Differential Revision: https://reviews.freebsd.org/D41481
There's a hierarchy here and we should use it.
Improves: cbeacb7c46f3a3650e5dbefa9a1a18bc9943a8cc
Reviewed by: jrtc27, jhb, emaste
Sponsored by: DARPA
Differential Revision: https://reviews.freebsd.org/D41456
