Place strings ending at page boundary without the null byte. If an
implementation goes beyond EXP_LEN, it will trigger the segfault.
(cherry picked from commit cb882b21b6)
Since __strlen_evex and __strnlen_evex added by
commit 1fd8c163a8
Author: H.J. Lu <hjl.tools@gmail.com>
Date: Fri Mar 5 06:24:52 2021 -0800
x86-64: Add ifunc-avx2.h functions with 256-bit EVEX
use sarx:
c4 e2 6a f7 c0 sarx %edx,%eax,%eax
require BMI2 for __strlen_evex and __strnlen_evex in ifunc-impl-list.c.
ifunc-avx2.h already requires BMI2 for EVEX implementation.
(cherry picked from commit 55bf411b45)
Update ifunc-memmove.h to select the function optimized with AVX512
instructions using ZMM16-ZMM31 registers to avoid RTM abort with usable
AVX512VL since VZEROUPPER isn't needed at function exit.
(cherry picked from commit e4fda46310)
Update ifunc-memset.h/ifunc-wmemset.h to select the function optimized
with AVX512 instructions using ZMM16-ZMM31 registers to avoid RTM abort
with usable AVX512VL and AVX512BW since VZEROUPPER isn't needed at
function exit.
(cherry picked from commit 4e2d8f3527)
At function exit, AVX optimized string/memory functions have VZEROUPPER
which triggers RTM abort. When such functions are called inside a
transactionally executing RTM region, RTM abort causes severe performance
degradation. Add tests to verify that string/memory functions won't
cause RTM abort in RTM region.
(cherry picked from commit 4bd660be40)
Since VZEROUPPER triggers RTM abort while VZEROALL won't, select AVX
optimized string/memory functions with
xtest
jz 1f
vzeroall
ret
1:
vzeroupper
ret
at function exit on processors with usable RTM, but without 256-bit EVEX
instructions to avoid VZEROUPPER inside a transactionally executing RTM
region.
(cherry picked from commit 7ebba91361)
Update ifunc-memcmp.h to select the function optimized with 256-bit EVEX
instructions using YMM16-YMM31 registers to avoid RTM abort with usable
AVX512VL, AVX512BW and MOVBE since VZEROUPPER isn't needed at function
exit.
(cherry picked from commit 91264fe357)
Update ifunc-memset.h/ifunc-wmemset.h to select the function optimized
with 256-bit EVEX instructions using YMM16-YMM31 registers to avoid RTM
abort with usable AVX512VL and AVX512BW since VZEROUPPER isn't needed at
function exit.
(cherry picked from commit 1b968b6b9b)
Update ifunc-memmove.h to select the function optimized with 256-bit EVEX
instructions using YMM16-YMM31 registers to avoid RTM abort with usable
AVX512VL since VZEROUPPER isn't needed at function exit.
(cherry picked from commit 63ad43566f)
Update ifunc-strcpy.h to select the function optimized with 256-bit EVEX
instructions using YMM16-YMM31 registers to avoid RTM abort with usable
AVX512VL and AVX512BW since VZEROUPPER isn't needed at function exit.
(cherry picked from commit 525bc2a32c)
Update ifunc-avx2.h, strchr.c, strcmp.c, strncmp.c and wcsnlen.c to
select the function optimized with 256-bit EVEX instructions using
YMM16-YMM31 registers to avoid RTM abort with usable AVX512VL, AVX512BW
and BMI2 since VZEROUPPER isn't needed at function exit.
For strcmp/strncmp, prefer AVX2 strcmp/strncmp if Prefer_AVX2_STRCMP
is set.
(cherry picked from commit 1fd8c163a8)
1. Set Prefer_No_VZEROUPPER if RTM is usable to avoid RTM abort triggered
by VZEROUPPER inside a transactionally executing RTM region.
2. Since to compare 2 32-byte strings, 256-bit EVEX strcmp requires 2
loads, 3 VPCMPs and 2 KORDs while AVX2 strcmp requires 1 load, 2 VPCMPEQs,
1 VPMINU and 1 VPMOVMSKB, AVX2 strcmp is faster than EVEX strcmp. Add
Prefer_AVX2_STRCMP to prefer AVX2 strcmp family functions.
(cherry picked from commit 1da50d4bda)
Fixes [BZ# 28755] for wcsncmp by redirecting length >= 2^56 to
__wcscmp_avx2. For x86_64 this covers the entire address range so any
length larger could not possibly be used to bound `s1` or `s2`.
test-strcmp, test-strncmp, test-wcscmp, and test-wcsncmp all pass.
Signed-off-by: Noah Goldstein <goldstein.w.n@gmail.com>
(cherry picked from commit ddf0992cf5)
When parse_tunables tries to erase a tunable marked as SXID_ERASE for
setuid programs, it ends up setting the envvar string iterator
incorrectly, because of which it may parse the next tunable
incorrectly. Given that currently the implementation allows malformed
and unrecognized tunables pass through, it may even allow SXID_ERASE
tunables to go through.
This change revamps the SXID_ERASE implementation so that:
- Only valid tunables are written back to the tunestr string, because
of which children of SXID programs will only inherit a clean list of
identified tunables that are not SXID_ERASE.
- Unrecognized tunables get scrubbed off from the environment and
subsequently from the child environment.
- This has the side-effect that a tunable that is not identified by
the setxid binary, will not be passed on to a non-setxid child even
if the child could have identified that tunable. This may break
applications that expect this behaviour but expecting such tunables
to cross the SXID boundary is wrong.
Reviewed-by: Carlos O'Donell <carlos@redhat.com>
(cherry picked from commit 2ed18c5b53)
Instead of passing GLIBC_TUNABLES via the environment, pass the
environment variable from parent to child. This allows us to test
multiple variables to ensure better coverage.
The test list currently only includes the case that's already being
tested. More tests will be added later.
Reviewed-by: Carlos O'Donell <carlos@redhat.com>
(cherry picked from commit 061fe3f8ad)
Use the support_capture_subprogram_self_sgid to spawn an sgid child.
Reviewed-by: Carlos O'Donell <carlos@redhat.com>
(cherry picked from commit ca33528106)
Add a new function support_capture_subprogram_self_sgid that spawns an
sgid child of the running program with its own image and returns the
exit code of the child process. This functionality is used by at
least three tests in the testsuite at the moment, so it makes sense to
consolidate.
There is also a new function support_subprogram_wait which should
provide simple system() like functionality that does not set up file
actions. This is useful in cases where only the return code of the
spawned subprocess is interesting.
This patch also ports tst-secure-getenv to this new function. A
subsequent patch will port other tests. This also brings an important
change to tst-secure-getenv behaviour. Now instead of succeeding, the
test fails as UNSUPPORTED if it is unable to spawn a setgid child,
which is how it should have been in the first place.
Reviewed-by: Carlos O'Donell <carlos@redhat.com>
(cherry picked from commit 716a3bdc41)
The arch13 memmove variant is currently selected by the ifunc selector
if the Miscellaneous-Instruction-Extensions Facility 3 facility bit
is present, but the function is also using vector instructions.
If the vector support is not present, one is receiving an operation
exception.
Therefore this patch also checks for vector support in the ifunc
selector and in ifunc-impl-list.c.
Just to be sure, the configure check is now also testing an arch13
vector instruction and an arch13 Miscellaneous-Instruction-Extensions
Facility 3 instruction.
(cherry picked from commit 7759be2593)
In commit 745664bd79 a use-after-free
was fixed, but this led to an occasional double-free. This patch
tracks the "live" allocation better.
Tested manually by a third party.
Related: RHBZ 1927877
Reviewed-by: Siddhesh Poyarekar <siddhesh@sourceware.org>
Reviewed-by: Carlos O'Donell <carlos@redhat.com>
(cherry picked from commit dca565886b)
The conversion loop to the internal encoding does not follow
the interface contract that __GCONV_FULL_OUTPUT is only returned
after the internal wchar_t buffer has been filled completely. This
is enforced by the first of the two asserts in iconv/skeleton.c:
/* We must run out of output buffer space in this
rerun. */
assert (outbuf == outerr);
assert (nstatus == __GCONV_FULL_OUTPUT);
This commit solves this issue by queuing a second wide character
which cannot be written immediately in the state variable, like
other converters already do (e.g., BIG5-HKSCS or TSCII).
Reported-by: Tavis Ormandy <taviso@gmail.com>
(cherry picked from commit 7d88c6142c)
Calling an IFUNC function defined in unrelocated executable also leads to
segfault. Issue a fatal error message when calling IFUNC function defined
in the unrelocated executable from a shared library.
On x86, ifuncmain6pie failed with:
[hjl@gnu-cfl-2 build-i686-linux]$ ./elf/ifuncmain6pie --direct
./elf/ifuncmain6pie: IFUNC symbol 'foo' referenced in '/export/build/gnu/tools-build/glibc-32bit/build-i686-linux/elf/ifuncmod6.so' is defined in the executable and creates an unsatisfiable circular dependency.
[hjl@gnu-cfl-2 build-i686-linux]$ readelf -rW elf/ifuncmod6.so | grep foo
00003ff4 00000706 R_386_GLOB_DAT 0000400c foo_ptr
00003ff8 00000406 R_386_GLOB_DAT 00000000 foo
0000400c 00000401 R_386_32 00000000 foo
[hjl@gnu-cfl-2 build-i686-linux]$
Remove non-JUMP_SLOT relocations against foo in ifuncmod6.so, which
trigger the circular IFUNC dependency, and build ifuncmain6pie with
-Wl,-z,lazy.
(cherry picked from commits 6ea5b57afa
and 7137d682eb)
When copying with "rep movsb", if the distance between source and
destination is N*4GB + [1..63] with N >= 0, performance may be very
slow. This patch updates memmove-vec-unaligned-erms.S for AVX and
AVX512 versions with the distance in RCX:
cmpl $63, %ecx
// Don't use "rep movsb" if ECX <= 63
jbe L(Don't use rep movsb")
Use "rep movsb"
Benchtests data with bench-memcpy, bench-memcpy-large, bench-memcpy-random
and bench-memcpy-walk on Skylake, Ice Lake and Tiger Lake show that its
performance impact is within noise range as "rep movsb" is only used for
data size >= 4KB.
(cherry picked from commit 3ec5d83d2a)
The variant PCS support was ineffective because in the common case
linkmap->l_mach.plt == 0 but then the symbol table flags were ignored
and normal lazy binding was used instead of resolving the relocs early.
(This was a misunderstanding about how GOT[1] is setup by the linker.)
In practice this mainly affects SVE calls when the vector length is
more than 128 bits, then the top bits of the argument registers get
clobbered during lazy binding.
Fixes bug 26798.
(cherry picked from commit 558251bd87)
Add CPU detection of Neoverse N2 and Neoverse V1, and select __memcpy_simd as
the memcpy/memmove ifunc.
Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
(cherry picked from commit e11ed9d2b4)
Further optimize integer memcpy. Small cases now include copies up
to 32 bytes. 64-128 byte copies are split into two cases to improve
performance of 64-96 byte copies. Comments have been rewritten.
(cherry picked from commit 7000651327)
Increase the upper bound on medium cases from 96 to 128 bytes.
Now, up to 128 bytes are copied unrolled.
Increase the upper bound on small cases from 16 to 32 bytes so that
copies of 17-32 bytes are not impacted by the larger medium case.
Benchmarking:
The attached figures show relative timing difference with respect
to 'memcpy_generic', which is the existing implementation.
'memcpy_med_128' denotes the the version of memcpy_generic with
only the medium case enlarged. The 'memcpy_med_128_small_32' numbers
are for the version of memcpy_generic submitted in this patch, which
has both medium and small cases enlarged. The figures were generated
using the script from:
https://www.sourceware.org/ml/libc-alpha/2019-10/msg00563.html
Depending on the platform, the performance improvement in the
bench-memcpy-random.c benchmark ranges from 6% to 20% between
the original and final version of memcpy.S
Tested against GLIBC testsuite and randomized tests.
(cherry picked from commit b9f145df85)
On some microarchitectures performance of the backwards memmove improves if
the stores use STR with decreasing addresses. So change the memmove loop
in memcpy_advsimd.S to use 2x STR rather than STP.
Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
(cherry picked from commit bd394d131c)
Add a new memcpy using 128-bit Q registers - this is faster on modern
cores and reduces codesize. Similar to the generic memcpy, small cases
include copies up to 32 bytes. 64-128 byte copies are split into two
cases to improve performance of 64-96 byte copies. Large copies align
the source rather than the destination.
bench-memcpy-random is ~9% faster than memcpy_falkor on Neoverse N1,
so make this memcpy the default on N1 (on Centriq it is 15% faster than
memcpy_falkor).
Passes GLIBC regression tests.
Reviewed-by: Szabolcs Nagy <szabolcs.nagy@arm.com>
(cherry picked from commit 4a733bf375)
Given almost all uses of ENTRY are for string/memory functions,
align ENTRY to a cacheline to simplify things.
Reviewed-by: Carlos O'Donell <carlos@redhat.com>
(cherry picked from commit 34f0d01d5e)
Unsigned branch instructions could be used for r2 to fix the wrong
behavior when a negative length is passed to memcpy.
This commit fixes the armv7 version.
(cherry picked from commit beea361050)
Unsigned branch instructions could be used for r2 to fix the wrong
behavior when a negative length is passed to memcpy and memmove.
This commit fixes the generic arm implementation of memcpy amd memmove.
(cherry picked from commit 79a4fa341b)
strcmp-avx2.S: In avx2 strncmp function, strings are compared in
chunks of 4 vector size(i.e. 32x4=128 byte for avx2). After first 4
vector size comparison, code must check whether it already passed
the given offset. This patch implement avx2 offset check condition
for strncmp function, if both string compare same for first 4 vector
size.
(cherry picked from commit 75870237ff)
During cleanup, before returning from get*_r functions, the end*ent
calls must not change errno. Otherwise, an ERANGE error from the
underlying implementation can be hidden, causing unexpected lookup
failures. This commit introduces an internal_end*ent_noerror
function which saves and restore errno, and marks the original
internal_end*ent function as warn_unused_result, so that it is used
only in contexts were errors from it can be handled explicitly.
Reviewed-by: DJ Delorie <dj@redhat.com>
(cherry picked from commit 790b8dda44)
Since __x86_shared_non_temporal_threshold is defined as
long int __x86_shared_non_temporal_threshold;
and long int is 4 bytes for x32, use RDX_LP to compare against
__x86_shared_non_temporal_threshold in assembly code.
(cherry picked from commit 55c7bcc71b)
Add a C wrapper to pass arguments in
/* Control process execution. */
extern int prctl (int __option, ...) __THROW;
to prctl syscall:
extern int prctl (int, unsigned long int, unsigned long int,
unsigned long int, unsigned long int);
(cherry picked from commit ff026950e2)
LOADARGS_N in powerpc/sysdep.h uses argN as local variables. It breaks
when argN is also a function argument. Rename argN to _argN to avoid
conflict.
(cherry picked from commit 14f43dd34d)
Since the the U marker can only be applied to 2 unsigned long arguments
in syscalls.list files, add a C wrapper for process_vm_readv and
process_vm_writev syscals which have more than 2 unsigned long arguments.
(cherry picked from commit ad9fd65d71)
Mark unsigned long arguments in mmap, read, recv, recvfrom, send, sendto,
write, ioperm, sendfile64, setxattr, lsetxattr, fsetxattr, getxattr,
lgetxattr, fgetxattr, listxattr, llistxattr and flistxattr with U in
syscalls.list files.
(cherry picked from commit 86f4f2263b)
Add a test to pass 64-bit long arguments to syscall with undefined upper
32 bits on x32.
Tested on i386, x86-64 and x32 as well as with build-many-glibcs.py.
(cherry picked from commit 781dacc4f4)
