POSIX.1-2004 and the upcoming C23 agree that memccpy()'s arguments
are restrict qualified and must not overlap. In 2002, restrict
qualifiers were added to <string.h>'s declaration of the function.
Make things official and document that the arguments must not
overlap.
See also: 61b60edfd3
Approved by: kib
MFC after: 1 month
MFC to: stable/14
Apply the following automated changes to try to eliminate
no-longer-needed sys/cdefs.h includes as well as now-empty
blank lines in a row.
Remove /^#if.*\n#endif.*\n#include\s+<sys/cdefs.h>.*\n/
Remove /\n+#include\s+<sys/cdefs.h>.*\n+#if.*\n#endif.*\n+/
Remove /\n+#if.*\n#endif.*\n+/
Remove /^#if.*\n#endif.*\n/
Remove /\n+#include\s+<sys/cdefs.h>\n#include\s+<sys/types.h>/
Remove /\n+#include\s+<sys/cdefs.h>\n#include\s+<sys/param.h>/
Remove /\n+#include\s+<sys/cdefs.h>\n#include\s+<sys/capsicum.h>/
Sponsored by: Netflix
For the uncommon items: Go through the tree and remove sccs tags that
didn't fit any nice pattern. If in the neighborhood, other SCM tags were
removed when they were detritis of long-ago CVS somehow in the early
mists of the project. Some adjacent copyrights stringswere removed (they
duplicated the copyright notices in the file). This also removed
non-standard formations of omission of SCCS tags (usually by adding an
extra #if 0 somewhere.
After this commit, a number of strings tagged with the 'what' @(#)
prefix remain, but they are primarily copyright notices.
Sponsored by: Netflix
Remove ancient SCCS tags from the tree, automated scripting, with two
minor fixup to keep things compiling. All the common forms in the tree
were removed with a perl script.
Sponsored by: Netflix
The memcpy() function first appeared in AT&T System V UNIX and was
reimplemented for 4.3BSD-Tahoe. The mempcpy() function first appeared in
FreeBSD 13.1.
PR: 272227
MFC after: 1 week
Differential Revision: https://reviews.freebsd.org/D42630
These sys/cdefs.h are not needed. Purge them. They are mostly left-over
from the $FreeBSD$ removal. A few in libc are still required for macros
that cdefs.h defines. Keep those.
Sponsored by: Netflix
Differential Revision: https://reviews.freebsd.org/D42385
While strlcpy and snprintf are somewhat similar, there's big differences
between strlcat and snprintf which leads to confusion. Remove the
comparison, since it's ultimately not that useful: the snprintf man page
has similar language to strlcpy, so it doesn't provide a better
reference. The two implementations are otherwise unrelated.
Reviewed by: bcr
Sponsored by: Netflix
Differential Revision: https://reviews.freebsd.org/D27228
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
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
bcmp() returned the number of remaining bytes when the main loop exits.
In case of a match, this is zero, else a positive integer. On systems
where SIZE_MAX > INT_MAX, the implicit conversion from size_t to int in
the return value may cause the number of remaining bytes to overflow,
becoming zero and falsely indicating a successful comparison.
Fix the bug by always returning 0 on equality, 1 otherwise.
PR: 272474
Approved by: emaste
Reviewed by: imp
MFC After: 1 week
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D41011
Gcc warns of infinite recursion if we use __builtin_ffs*() to
implement ffs*(). This is because gcc uses ffs() to implement
these on some platforms. Sidestep the warning by using
__builtin_ctz*() for these.
Sponsored by: FreeBSD Foundation
Reported by: jlduran@gmail.com, jhb
Fixes: ee8b0c43 (D40730)
Reviewed by: jhb, mhorne
Approved by: jhb
MFC after: 1 week
Differential Revision: https://reviews.freebsd.org/D40966
Most architectures we support (except for riscv64) have instructions
to compute these functions very quickly. Replace old code with the
ffs and clz builtin functions, allowing clang to generate good code
for all architectures.
As a consequence, toss out arm and i386 ffs() implementations.
Sponsored by: FreeBSD Foundation
Approved by: mhorne
MFC after: 1 week
Differential Revision: https://reviews.freebsd.org/D40730
The SPDX folks have obsoleted the BSD-2-Clause-FreeBSD identifier. Catch
up to that fact and revert to their recommended match of BSD-2-Clause.
Discussed with: pfg
MFC After: 3 days
Sponsored by: Netflix
memmem started as a GNU extension but is now widely available.
Reviewed by: mhorne (slightly earlier version)
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D39337
Casting to int truncates size on some platforms, resulting swab not
copying all the data. Cast len to size_t to avoid right shifting a
signed value: we know here it's > 0, so we can safely cast it w/o losing
precision.
In addition, be more careful with signedness of char pointers and
temporaries. Downgrade tmp from unsigned long to unsigned char since
we're only reading and writing characters.
Reviewed by: imp
Pull Request: https://github.com/freebsd/freebsd-src/pull/516
Add a strverscmp(3) function to libc, a GNU extension I implemented by
reading its glibc manual page. It orders strings following a much more
natural ordering (e.g. "ent1 < ent2 < ent10" as opposed to
"ent1 < ent10 < ent2" with strcmp(3)'s lexicographic ordering).
Also add versionsort(3) for use as scandir(3)'s compar argument.
Update manual page for scandir(3) and add one for strverscmp(3).
Reviewed by: pstef, gbe, kib
MFC after: 1 week
Differential Revision: https://reviews.freebsd.org/D35807
This has already been done for most files that have the Foundation as
the only listed copyright holder. Do it now for files that list
multiple copyright holders, but have the Foundation copyright in its own
section.
Sponsored by: The FreeBSD Foundation
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
MFC after: 1 month
Differential Revision: https://reviews.freebsd.org/D34759
The removed text claimed that memcpy is implemented using bcopy and thus
strings may overlap. Use of bcopy is an implementation detail that is
no longer true, even if the implementation (on some archs) does allow
overlap.
In any case behaviour is undefined per the C standard if memcpy is
called with overlapping objects, and this man page already claimed that
src and dst may not overlap.
Reviewed by: kib
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D31192
They deliberately read out-of-bounds values to avoid byte-by-byte
loads and check multiple bytes at once. While this will work on x86,
it is flagged as an out-of-bounds read with ASAN, so we have to
disable instrumentation here. This also causes bounds errors for CHERI,
so in CheriBSD we use implementations that avoid OOB reads.
Differential Revision: https://reviews.freebsd.org/D31045
Finally, we have the correct function definition for strmode. NetBSD/OpenBSD
did this many years ago. This code is weird sign extension safe.
Reviewed by: imp@
Pull Request: https://github.com/freebsd/freebsd-src/pull/493
While most 64-bit architectures have an assembly implementation of this
file, RISC-V does not. As we now store 8 bytes instead of 4 it should speed
up RISC-V.
Reviewed By: kib
MFC after: 1 week
Differential Revision: https://reviews.freebsd.org/D29536
While most 64-bit architectures have an assembly implementation of this
file RISC-V does not. As we now copy 8 bytes instead of 4 it should speed
up RISC-V. Using intptr_t instead of int also allows using this file for
CHERI pure-capability code since trying to copy pointers using integer
loads/stores will invalidate pointers.
Reviewed By: kib
Obtained from: CheriBSD (partially)
MFC after: 1 week
Differential Revision: https://reviews.freebsd.org/D29535
Parentheses added to HASZERO macro to avoid a GCC warning, and formatted
with clang-format as we have adopted these and don't consider them
'contrib' code.
Obtained from: musl (snapshot at commit 4d0a82170a25)
Reviewed by: kib (libc integration), mjg (both earlier)
MFC after: 1 month
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D17630
All supported platforms support thread-local vars and __thread.
Reviewed by: emaste
Sponsored by: The FreeBSD Foundation
MFC after: 1 week
Differential Revision: https://reviews.freebsd.org/D28796
This reverts commit 710e45c4b8.
It breaks for some corner cases on big endian ppc64.
Given the stage of the release process it is best to revert for now.
Reported by: jhibbits
The previous code neglected to use primitives which can find the end
of the string without having to branch on every character.
While here augment the somewhat misleading commentary -- strlen as
implemented here leaves performance on the table, especially so for
userspace. Every arch should get a dedicated variant instead.
In the meantime this commit lessens the problem.
Tested with glibc test suite.
Naive test just calling strlen in a loop on Haswell (ops/s):
$(perl -e "print 'A' x 3"):
before: 211198039
after: 338626619
$(perl -e "print 'A' x 100"):
before: 83151997
after: 98285919
Only for the arches that provide user-mode TLS.
PR: 251651
Requested by: yuri
Discussed with: emaste, jilles, tijl
Sponsored by: The FreeBSD Foundation
Differential revision: https://reviews.freebsd.org/D27495
MFC after: 2 weeks
Linux claims 4.3BSD, we claim 4.4BSD and OpenBSD claims 4.3BSD-Reno. It turns
out that OpenBSD got it right: the function was added in late 1988 a few months
after 4.3BSD-Tahoe, well in advance of 4.3BSD-Reno.
Reviewed by: bcr
Approved by: bcr
Differential Revision: https://reviews.freebsd.org/D27392
unsigned char promotes to int, which can overflow when shifted left by
24 bits or more. this has been reported multiple times but then
forgotten. it's expected to be benign UB, but can trap when built with
explicit overflow catching (ubsan or similar). fix it now.
note that promotion to uint32_t is safe and portable even outside of
the assumptions usually made in musl, since either uint32_t has rank
at least unsigned int, so that no further default promotions happen,
or int is wide enough that the shift can't overflow. this is a
desirable property to have in case someone wants to reuse the code
elsewhere.
musl commit: 593caa456309714402ca4cb77c3770f4c24da9da
Obtained from: musl
first, the condition (mem && k < p) is redundant, because mem being
nonzero implies the needle is periodic with period exactly p, in which
case any byte that appears in the needle must appear in the last p
bytes of the needle, bounding the shift (k) by p.
second, the whole point of replacing the shift k by mem (=l-p) is to
prevent shifting by less than mem when discarding the memory on shift,
in which case linear time could not be guaranteed. but as written, the
check also replaced shifts greater than mem by mem, reducing the
benefit of the shift. there is no possible benefit to this reduction of
the shift; since mem is being cleared, the full shift is valid and
more optimal. so only replace the shift by mem when it would be less
than mem.
musl commits:
8f5a820d147da36bcdbddd201b35d293699dacd8
122d67f846cb0be2c9e1c3880db9eb9545bbe38c
Obtained from: musl
MFC after: 2 weeks
We have adopted these and don't consider them 'contrib' code, so bring
them closer to style(9). This is a followon to r315467 and r351700.
MFC after: 1 week
Sponsored by: The FreeBSD Foundation