In short: __tls_get_addr checks the global generation counter and if
the current dtv is older then _dl_update_slotinfo updates dtv up to the
generation of the accessed module. So if the global generation is newer
than generation of the module then __tls_get_addr keeps hitting the
slow dtv update path. The dtv update path includes a number of checks
to see if any update is needed and this already causes measurable tls
access slow down after dlopen.
It may be possible to detect up-to-date dtv faster. But if there are
many modules loaded (> TLS_SLOTINFO_SURPLUS) then this requires at
least walking the slotinfo list.
This patch tries to update the dtv to the global generation instead, so
after a dlopen the tls access slow path is only hit once. The modules
with larger generation than the accessed one were not necessarily
synchronized before, so additional synchronization is needed.
This patch uses acquire/release synchronization when accessing the
generation counter.
Note: in the x86_64 version of dl-tls.c the generation is only loaded
once, since relaxed mo is not faster than acquire mo load.
I have not benchmarked this. Tested by Adhemerval Zanella on aarch64,
powerpc, sparc, x86 who reported that it fixes the performance issue
of bug 19924.
Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
The old Intel software developer manual specified that the low byte of
EAX of CPUID leaf 2 returned 1 which indicated the number of rounds of
CPUDID leaf 2 was needed to retrieve the complete cache information. The
newer Intel manual has been changed to that it should always return 1
and be ignored. If the lower byte isn't 1, CPUID leaf 2 can't be used.
In this case, we ignore CPUID leaf 2 and use CPUID leaf 4 instead. If
CPUID leaf 4 doesn't contain the cache information, cache information
isn't available at all. This addresses BZ #30643.
According to glibc memcmp microbenchmark test results(Add generic
memcmp), this implementation have performance improvement
except the length is less than 3, details as below:
Name Percent of time reduced
memcmp-lasx 16%-74%
memcmp-lsx 20%-50%
memcmp-aligned 5%-20%
According to glibc memset microbenchmark test results, for LSX and LASX
versions, A few cases with length less than 8 experience performace
degradation, overall, the LASX version could reduce the runtime about
15% - 75%, LSX version could reduce the runtime about 15%-50%.
The unaligned version uses unaligned memmory access to set data which
length is less than 64 and make address aligned with 8. For this part,
the performace is better than aligned version. Comparing with the generic
version, the performance is close when the length is larger than 128. When
the length is 8-128, the unaligned version could reduce the runtime about
30%-70%, the aligned version could reduce the runtime about 20%-50%.
According to glibc memrchr microbenchmark, this implementation could reduce
the runtime as following:
Name Percent of rutime reduced
memrchr-lasx 20%-83%
memrchr-lsx 20%-64%
According to glibc memchr microbenchmark, this implementation could reduce
the runtime as following:
Name Percent of runtime reduced
memchr-lasx 37%-83%
memchr-lsx 30%-66%
memchr-aligned 0%-15%
According to glibc rawmemchr microbenchmark, A few cases tested with
char '\0' experience performance degradation due to the lasx and lsx
versions don't handle the '\0' separately. Overall, rawmemchr-lasx
implementation could reduce the runtime about 40%-80%, rawmemchr-lsx
implementation could reduce the runtime about 40%-66%, rawmemchr-aligned
implementation could reduce the runtime about 20%-40%.
We are requiring Binutils >= 2.41, so explicit relocation syntax is
always supported by the assembler. Use it to reduce one instruction.
Signed-off-by: Xi Ruoyao <xry111@xry111.site>
This patch adds the new F_SEAL_EXEC constant from Linux 6.3 (see Linux
commit 6fd7353829c ("mm/memfd: add F_SEAL_EXEC") to bits/fcntl-linux.h.
Signed-off-by: Kir Kolyshkin <kolyshkin@gmail.com>
Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
This patch adds a new macro, M68K_SCALE_AVAILABLE, similar to gmp
scale_available_p (mpn/m68k/m68k-defs.m4) that expand to 1 if a
scale factor can be used in addressing modes. This is used
instead of __mc68020__ for some optimization decisions.
Checked on a build for m68k-linux-gnu target mc68020 and mc68040.
GCC currently does not define __mc68020__ for -mcpu=68040 or higher,
which memcpy/memmove assumptions. Since this memory copy optimization
seems only intended for m68020, disable for other m680X0 variants.
Checked on a build for m68k-linux-gnu target mc68020 and mc68040.
Based on the glibc microbenchmark, only a few short inputs with this
strncmp-aligned and strncmp-lsx implementation experience performance
degradation, overall, strncmp-aligned could reduce the runtime 0%-10%
for aligned comparision, 10%-25% for unaligend comparision, strncmp-lsx
could reduce the runtime about 0%-60%.
Based on the glibc microbenchmark, strcmp-aligned implementation could
reduce the runtime 0%-10% for aligned comparison, 10%-20% for unaligned
comparison, strcmp-lsx implemenation could reduce the runtime 0%-50%.
Based on the glibc microbenchmark, strnlen-aligned implementation could
reduce the runtime more than 10%, strnlen-lsx implementation could reduce
the runtime about 50%-78%, strnlen-lasx implementation could reduce the
runtime about 50%-88%.
The path auxv[*].a_val could either be an integer or a string,
depending on the a_type value. Use a separate field, a_val_string, to
simplify mechanical parsing of the --list-diagnostics output.
Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
On Skylake, it changes log1p bench performance by:
Before After Improvement
max 63.349 58.347 8%
min 4.448 5.651 -30%
mean 12.0674 10.336 14%
The minimum code path is
if (hx < 0x3FDA827A) /* x < 0.41422 */
{
if (__glibc_unlikely (ax >= 0x3ff00000)) /* x <= -1.0 */
{
...
}
if (__glibc_unlikely (ax < 0x3e200000)) /* |x| < 2**-29 */
{
math_force_eval (two54 + x); /* raise inexact */
if (ax < 0x3c900000) /* |x| < 2**-54 */
{
...
}
else
return x - x * x * 0.5;
FMA and non-FMA code sequences look similar. Non-FMA version is slightly
faster. Since log1p is called by asinh and atanh, it improves asinh
performance by:
Before After Improvement
max 75.645 63.135 16%
min 10.074 10.071 0%
mean 15.9483 14.9089 6%
and improves atanh performance by:
Before After Improvement
max 91.768 75.081 18%
min 15.548 13.883 10%
mean 18.3713 16.8011 8%
The static PIE configure check uses link tests. When bootstrapping
a cross-toolchain, the link tests fail due to missing crt-files /
libc.so. As we explicitely want to test an issue in binutils (ld),
we now also explicitely check for known linker versions.
See also commit 368b7c614b
S390: Use compile-only instead of also link-tests in configure.
These implementations improve the time to copy data in the glibc
microbenchmark as below:
memcpy-lasx reduces the runtime about 8%-76%
memcpy-lsx reduces the runtime about 8%-72%
memcpy-unaligned reduces the runtime of unaligned data copying up to 40%
memcpy-aligned reduece the runtime of unaligned data copying up to 25%
memmove-lasx reduces the runtime about 20%-73%
memmove-lsx reduces the runtime about 50%
memmove-unaligned reduces the runtime of unaligned data moving up to 40%
memmove-aligned reduces the runtime of unaligned data moving up to 25%
These implementations improve the time to run strchr{nul}
microbenchmark in glibc as below:
strchr-lasx reduces the runtime about 50%-83%
strchr-lsx reduces the runtime about 30%-67%
strchr-aligned reduces the runtime about 10%-20%
strchrnul-lasx reduces the runtime about 50%-83%
strchrnul-lsx reduces the runtime about 36%-65%
strchrnul-aligned reduces the runtime about 6%-10%
SYS_modify_ldt requires CONFIG_MODIFY_LDT_SYSCALL to be set in the kernel, which
some distributions may disable for hardening. Check if that's the case (unset)
and mark the test as UNSUPPORTED if so.
Reviewed-by: DJ Delorie <dj@redhat.com>
Signed-off-by: Sam James <sam@gentoo.org>
All callers pass 1 or 0x11 anyway (same meaning according to man page),
but still.
Reviewed-by: DJ Delorie <dj@redhat.com>
Signed-off-by: Sam James <sam@gentoo.org>
On Skylake, it improves expm1 bench performance by:
Before After Improvement
max 70.204 68.054 3%
min 20.709 16.2 22%
mean 22.1221 16.7367 24%
NB: Add
extern long double __expm1l (long double);
extern long double __expm1f128 (long double);
for __typeof (__expm1l) and __typeof (__expm1f128) when __expm1 is
defined since __expm1 may be expanded in their declarations which
causes the build failure.
strlen-lasx is implemeted by LASX simd instructions(256bit)
strlen-lsx is implemeted by LSX simd instructions(128bit)
strlen-align is implemented by LA basic instructions and never use unaligned memory acess
LoongArch glibc can add some LASX/LSX vector instructions codes,
change the required minimum binutils version to 2.41 which could
support vector instructions. HAVE_LOONGARCH_VEC_ASM is removed
accordingly.
The following usage of macro LEAF/ENTRY are all feasible:
1. LEAF(fcn) -- the align value of fcn is .align 3(default value)
2. LEAF(fcn, 6) -- the align value of fcn is .align 6
The:
```
if (shared_per_thread > 0 && threads > 0)
shared_per_thread /= threads;
```
Code was accidentally moved to inside the else scope. This doesn't
match how it was previously (before af992e7abd).
This patch fixes that by putting the division after the `else` block.
The nscd daemon caches hosts data from NSS modules verbatim, without
filtering protocol families or sorting them (otherwise separate caches
would be needed for certain ai_flags combinations). The cache
implementation is complete separate from the getaddrinfo code. This
means that rebuilding getaddrinfo is not needed. The only function
actually used is __bump_nl_timestamp from check_pf.c, and this change
moves it into nscd/connections.c.
Tested on x86_64-linux-gnu with -fexceptions, built with
build-many-glibcs.py. I also backported this patch into a distribution
that still supports nscd and verified manually that caching still works.
Reviewed-by: Siddhesh Poyarekar <siddhesh@sourceware.org>
Since i686 provides the fortified wrappers for memcpy, mempcpy,
memmove, and memset on the same string implementation, the static
build tries to optimized it by not tying the fortified wrappers
to string routine (to avoid pulling the fortify function if
they are not required).
Checked on i686-linux-gnu building with different option:
default and --disable-multi-arch plus default, --disable-default-pie,
--enable-fortify-source={2,3}, and --enable-fortify-source={2,3}
with --disable-default-pie.
Reviewed-by: Siddhesh Poyarekar <siddhesh@sourceware.org>
With multiarch disabled, the default memmove implementation provides
the fortify routines for memcpy, mempcpy, and memmove. However, it
does not provide the internal hidden definitions used when building
with fortify enabled. The memset has a similar issue.
Checked on x86_64-linux-gnu building with different options:
default and --disable-multi-arch plus default, --disable-default-pie,
--enable-fortify-source={2,3}, and --enable-fortify-source={2,3}
with --disable-default-pie.
Tested-by: Andreas K. Huettel <dilfridge@gentoo.org>
Reviewed-by: Siddhesh Poyarekar <siddhesh@sourceware.org>
Linux 6.4 adds new constants PTRACE_SET_SYSCALL_USER_DISPATCH_CONFIG
and PTRACE_GET_SYSCALL_USER_DISPATCH_CONFIG. Add those to all
relevant sys/ptrace.h headers, along with adding the associated
argument structure to bits/ptrace-shared.h (named struct
__ptrace_sud_config there following the usual convention for such
structures).
Tested for x86_64 and with build-many-glibcs.py.
Making error_t defined to enum __error_t_codes conveniently makes the
debugger print symbolic values, but in C++ int is not interoperable with
enum __error_t_codes, leading to C++ application build issues, so let's
revert error_t to int in C++.
This is the only missing part in struct statvfs.
The LSB calls [f]statfs() deprecated, and its weird types are definitely
off-putting. However, its use is required to get f_type.
Instead, allocate one of the six spares to f_type,
copied directly from struct statfs.
This then becomes a small glibc extension to the standard interface
on Linux and the Hurd, instead of two different interfaces, one of which
is quite odd due to being an ABI type, and there no longer is any reason
to use statfs().
The underlying kernel type is a mess, but all architectures agree on u32
(or more) for the ABI, and all filesystem magicks are 32-bit integers.
We don't lose any generality by using u32, and by doing so we both make
the API consistent with the Hurd, and allow C++
switch(f_type) { case RAMFS_MAGIC: ...; }
Also fix tst-statvfs so that it actually fails;
as it stood, all it did was return 0 always.
Test statfs()' and statvfs()' f_types are the same.
Link: https://lore.kernel.org/linux-man/f54kudgblgk643u32tb6at4cd3kkzha6hslahv24szs4raroaz@ogivjbfdaqtb/t/#u
Signed-off-by: Ahelenia Ziemiańska <nabijaczleweli@nabijaczleweli.xyz>
Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
When using jemalloc, malloc() needs to use TSD, while libpthread
initialization needs malloc(). Having ___pthread_self set early to some
static storage allows TSD to work early, thus allowing jemalloc and
libpthread to initialize together.
This incidentaly simplifies __pthread_enable/disable_asynccancel and
__pthread_self, now that ___pthread_self is always initialized.
When using jemalloc, malloc() needs to use TSD, while libpthread
initialization needs malloc(). Supporting a static TSD area allows jemalloc
and libpthread to initialize together.
Some legacy AMD CPUs and hypervisors have the _cpuid_ '0x8000_001D'
set to Zero, thus resulting in zeroed-out computed cache values.
This patch reintroduces the old way of cache computation as a
fail-safe option to handle these exceptions.
Fixed 'level4_cache_size' value through handle_amd().
Reviewed-by: Premachandra Mallappa <premachandra.mallappa@amd.com>
Tested-by: Florian Weimer <fweimer@redhat.com>
04bf7d2d8a ("chk: Add and fix hidden builtin definitions for *_chk")
added an #undef for longjmp and siglongjmp to compensate for the
definition in include/setjmp.h, but missed doing so for the powerpc
version too.
Fixes: 04bf7d2d8a ("chk: Add and fix hidden builtin definitions for
*_chk")
This patch updates the kernel version in the tests tst-mman-consts.py,
tst-mount-consts.py and tst-pidfd-consts.py to 6.4. (There are no new
constants covered by these tests in 6.4 that need any other header
changes.)
Tested with build-many-glibcs.py.
This patch enables the option to influence hwcaps used by PowerPC.
The environment variable, GLIBC_TUNABLES=glibc.cpu.hwcaps=-xxx,yyy,-zzz....,
can be used to enable CPU/ARCH feature yyy, disable CPU/ARCH feature xxx
and zzz, where the feature name is case-sensitive and has to match the ones
mentioned in the file{sysdeps/powerpc/dl-procinfo.c}.
Note that the hwcap tunables only used in the IFUNC selection.
Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
On __convert_scm_timestamps GCC 6 issues an warning that tvts[0]/tvts[1]
maybe be used uninitialized, however it would be used if type is set to a
value different than 0 (done by either COMPAT_SO_TIMESTAMP_OLD or
COMPAT_SO_TIMESTAMPNS_OLD) which will fallthrough to 'common' label.
It does not show with gcc 7 or more recent versions.
Checked on i686-linux-gnu.
Reviewed-by: Carlos O'Donell <carlos@redhat.com>
Similar to memcpy, mempcpy, and memmove there is no need for an
specific memset_chk-nonshared.S. It can be provided by
memset-ia32.S itself for static library.
Checked on i686-linux-gnu.
Reviewed-by: Carlos O'Donell <carlos@redhat.com>
The i386 string routines provide multiple internal definitions
for memcpy, memmove, and mempcpy chk routines:
$ objdump -t libc.a | grep __memcpy_chk
00000000 g F .text 0000000e __memcpy_chk
00000000 g F .text 00000013 __memcpy_chk
$ objdump -t libc.a | grep __mempcpy_chk
00000000 g F .text 0000000e __mempcpy_chk
00000000 g F .text 00000013 __mempcpy_chk
$ objdump -t libc.a | grep __memmove_chk
00000000 g F .text 0000000e __memmove_chk
00000000 g F .text 00000013 __memmove_chk
Although is not an issue for normal static builds, with fortify=3
glibc itself might use the fortify chk functions and thus static
build might fail with multiple definitions. For instance:
x86_64-glibc-linux-gnu-gcc -m32 -march=i686 -o [...]math/test-signgam-uchar-static -nostdlib -nostartfiles -static -static-pie [...]
x86_64-glibc-linux-gnu/bin/ld: [...]/libc.a(mempcpy-ia32.o):
in function `__mempcpy_chk': [...]/glibc-git/string/../sysdeps/i386/i686/mempcpy.S:32: multiple definition of `__mempcpy_chk';
[...]/libc.a(mempcpy_chk-nonshared.o):[...]/debug/../sysdeps/i386/mempcpy_chk.S:28: first defined here
collect2: error: ld returned 1 exit status
make[2]: *** [../Rules:298:
There is no need for mem*-nonshared.S, the __mem*_chk routines
are already provided by the assembly routines.
Checked on i686-linux-gnu with gcc 13 built with fortify=1,2,3 and
without fortify.
Reviewed-by: Carlos O'Donell <carlos@redhat.com>
The compiler might not see that internal definition is an alias
due the libc_ifunc macro, which redefines __strchrnul. With
gcc 6 it fails with:
In file included from <command-line>:0:0:
./../include/libc-symbols.h:472:33: error: ‘__EI___strchrnul’ aliased to
undefined symbol ‘__GI___strchrnul’
extern thread __typeof (name) __EI_##name \
^
./../include/libc-symbols.h:468:3: note: in expansion of macro
‘__hidden_ver2’
__hidden_ver2 (, local, internal, name)
^~~~~~~~~~~~~
./../include/libc-symbols.h:476:29: note: in expansion of macro
‘__hidden_ver1’
# define hidden_def(name) __hidden_ver1(__GI_##name, name, name);
^~~~~~~~~~~~~
./../include/libc-symbols.h:557:32: note: in expansion of macro
‘hidden_def’
# define libc_hidden_def(name) hidden_def (name)
^~~~~~~~~~
../sysdeps/powerpc/powerpc64/multiarch/strchrnul.c:38:1: note: in
expansion of macro ‘libc_hidden_def’
libc_hidden_def (__strchrnul)
^~~~~~~~~~~~~~~
Use libc_ifunc_hidden as stpcpy. Checked on powerpc64 with
gcc 6 and gcc 13.
Reviewed-by: Carlos O'Donell <carlos@redhat.com>
Generated on a Cavium Octeon III 2 board running Linux version 4.19.249
and GCC 13.1.0.
Needed due to commit cf7ffdd8a5 ("added pair of inputs for hypotf in
binary32").
Starting with commit 2c6b4b272e
"nptl: Unconditionally use a 32-byte rseq area", the testcase
misc/tst-rseq-disable is UNSUPPORTED as RSEQ_SIG is not defined.
The mentioned commit removes inclusion of sys/rseq.h in nptl/descr.h.
Thus just include sys/rseq.h in the tst-rseq-disable.c as also done
in tst-rseq.c and tst-rseq-nptl.c.
Reviewed-by: Florian Weimer <fweimer@redhat.com>
Generated on a VisionFive 2 board running Linux version 6.4.2 and
GCC 13.1.0.
Needed due to commit cf7ffdd8a5 ("added pair of inputs for hypotf in
binary32").
Based on feedback by Mike Gilbert <floppym@gentoo.org>
Linux-6.1.38-dist x86_64 AMD Phenom-tm- II X6 1055T Processor
-march=amdfam10
failures occur for x32 ABI
Signed-off-by: Andreas K. Hüttel <dilfridge@gentoo.org>
On some machines we end up with incomplete cache information. This can
make the new calculation of `sizeof(total-L3)/custom-divisor` end up
lower than intended (and lower than the prior value). So reintroduce
the old bound as a lower bound to avoid potentially regressing code
where we don't have complete information to make the decision.
Reviewed-by: DJ Delorie <dj@redhat.com>
After:
```
commit af992e7abd
Author: Noah Goldstein <goldstein.w.n@gmail.com>
Date: Wed Jun 7 13:18:01 2023 -0500
x86: Increase `non_temporal_threshold` to roughly `sizeof_L3 / 4`
```
Split `shared` (cumulative cache size) from `shared_per_thread` (cache
size per socket), the `shared_per_thread` *can* be slightly off from
the previous calculation.
Previously we added `core` even if `threads_l2` was invalid, and only
used `threads_l2` to divide `core` if it was present. The changed
version only included `core` if `threads_l2` was valid.
This change restores the old behavior if `threads_l2` is invalid by
adding the entire value of `core`.
Reviewed-by: DJ Delorie <dj@redhat.com>
Based on feedback by Arsen Arsenović <arsen@gentoo.org>
Linux-6.1.38-gentoo-dist-hardened x86_64 AMD Ryzen 7 3800X 8-Core Processor
-march=x86-64-v2
Signed-off-by: Andreas K. Hüttel <dilfridge@gentoo.org>
Bump autoconf requirement to 2.71 to allow regenerating configure on
more recent distributions. autoconf 2.71 has been in Fedora since F36
and is the current version in Debian stable (bookworm). It appears to
be current in Gentoo as well.
All sysdeps configure and preconfigure scripts have also been
regenerated; all changes are trivial transformations that do not affect
functionality.
Signed-off-by: Siddhesh Poyarekar <siddhesh@sourceware.org>
Reviewed-by: Carlos O'Donell <carlos@redhat.com>
It follows the internal signature:
extern int clone3 (struct clone_args *__cl_args, size_t __size,
int (*__func) (void *__arg), void *__arg);
Checked on s390x-linux-gnu and s390-linux-gnu.
The sparc ABI has multiple cases on how to handle JMP_SLOT relocations,
(sparc_fixup_plt/sparc64_fixup_plt). For BINDNOW, _dl_audit_symbind
will be responsible to setup the final relocation value; while for
lazy binding _dl_fixup/_dl_profile_fixup will call the audit callback
and tail cail elf_machine_fixup_plt (which will call
sparc64_fixup_plt).
This patch fixes by issuing the SPARC specific routine on bindnow and
forwarding the audit value to elf_machine_fixup_plt for lazy resolution.
It fixes the la_symbind for bind-now tests on sparc64 and sparcv9:
elf/tst-audit24a
elf/tst-audit24b
elf/tst-audit24c
elf/tst-audit24d
Checked on sparc64-linux-gnu and sparcv9-linux-gnu.
Tested-by: John Paul Adrian Glaubitz <glaubitz@physik.fu-berlin.de>
This patch checks if assembler supports vector instructions to
generate LASX/LSX code or not, and then define HAVE_LOONGARCH_VEC_ASM macro
We have added support for vector instructions in binutils-2.41
See:
https://sourceware.org/git/?p=binutils-gdb.git;a=commit;h=75b2f521b101d974354f6ce9ed7c054d8b2e3b7a
commit 75b2f521b101d974354f6ce9ed7c054d8b2e3b7a
Author: mengqinggang <mengqinggang@loongson.cn>
Date: Thu Jun 22 10:35:28 2023 +0800
LoongArch: gas: Add lsx and lasx instructions support
gas/ChangeLog:
* config/tc-loongarch.c (md_parse_option): Add lsx and lasx option.
(loongarch_after_parse_args): Add lsx and lasx option.
opcodes/ChangeLog:
* loongarch-opc.c (struct loongarch_ase): Add lsx and lasx
instructions.
Depending on build configuration, the [routine]-c.c files may be chosen
to provide fortified routines implementation. While [routines].c
implementation were automatically excluded, the [routines]-c.c ones were
not. This patch fixes that by adding these file to the list to be
filtered.
Return value from *scanf and *asprintf routines are now properly checked
in test-scanf-ldbl-compat-template.c and test-printf-ldbl-compat.c.
Reviewed-by: Siddhesh Poyarekar <siddhesh@sourceware.org>
This allows to include bits/syslog-decl.h in include/sys/syslog.h and
therefore be able to create the libc_hidden_builtin_proto (__syslog_chk)
prototype.
Reviewed-by: Siddhesh Poyarekar <siddhesh@sourceware.org>
The change is meant to avoid unwanted PLT entries for the wmemset and
wcrtomb routines when _FORTIFY_SOURCE is set.
On top of that, ensure that *_chk routines have their hidden builtin
definitions available.
Reviewed-by: Siddhesh Poyarekar <siddhesh@sourceware.org>
If libc_hidden_builtin_{def,proto} isn't properly set for *_chk routines,
there are unwanted PLT entries in libc.so.
There is a special case with __asprintf_chk:
If ldbl_* macros are used for asprintf, ABI gets broken on s390x,
if it isn't, ppc64le isn't building due to multiple asm redirections.
This is due to the inclusion of bits/stdio-lbdl.h for ppc64le whereas it
isn't for s390x. This header creates redirections, which are not
compatible with the ones generated using libc_hidden_def.
Yet, we can't use libc_hidden_ldbl_proto on s390x since it will not
create a simple strong alias (e.g. as done on x86_64), but a versioned
alias, leading to ABI breakage.
This results in errors on s390x:
/usr/bin/ld: glibc/iconv/../libio/bits/stdio2.h:137: undefined reference
to `__asprintf_chk'
Original __asprintf_chk symbols:
00000000001395b0 T __asprintf_chk
0000000000177e90 T __nldbl___asprintf_chk
__asprintf_chk symbols with ldbl_* macros:
000000000012d590 t ___asprintf_chk
000000000012d590 t __asprintf_chk@@GLIBC_2.4
000000000012d590 t __GI___asprintf_chk
000000000012d590 t __GL____asprintf_chk___asprintf_chk
0000000000172240 T __nldbl___asprintf_chk
__asprintf_chk symbols with the patch:
000000000012d590 t ___asprintf_chk
000000000012d590 T __asprintf_chk
000000000012d590 t __GI___asprintf_chk
0000000000172240 T __nldbl___asprintf_chk
Reviewed-by: Carlos O'Donell <carlos@redhat.com>
If libc_hidden_builtin_{def,proto} isn't properly set for *_chk routines,
there are unwanted PLT entries in libc.so.
Reviewed-by: Siddhesh Poyarekar <siddhesh@sourceware.org>
The *_chk routines naming doesn't match the name that would be generated
using libc_hidden_ldbl_proto. Since the macro is needed for some of
these *_chk functions for _FORTIFY_SOURCE to be enabled, that needed to
be fixed.
While at it, all the *_chk function get renamed appropriately for
consistency, even if not strictly necessary.
Reviewed-by: Siddhesh Poyarekar <siddhesh@sourceware.org>
Reviewed-by: Paul E. Murphy <murphyp@linux.ibm.com>
Since the _FORTIFY_SOURCE feature uses some routines of Glibc, they need to
be excluded from the fortification.
On top of that:
- some tests explicitly verify that some level of fortification works
appropriately, we therefore shouldn't modify the level set for them.
- some objects need to be build with optimization disabled, which
prevents _FORTIFY_SOURCE to be used for them.
Assembler files that implement architecture specific versions of the
fortified routines were not excluded from _FORTIFY_SOURCE as there is no
C header included that would impact their behavior.
Reviewed-by: Siddhesh Poyarekar <siddhesh@sourceware.org>
MAP_FIXED is defined to silently replace any existing mappings at the
address range being mapped over. This, however, is a dangerous, and only
rarely desired behavior.
Various Unix systems provide replacements or additions to MAP_FIXED:
* SerenityOS and Linux provide MAP_FIXED_NOREPLACE. If the address space
already contains a mapping in the requested range, Linux returns
EEXIST. SerenityOS returns ENOMEM, however that is a bug, as the
MAP_FIXED_NOREPLACE implementation is intended to be compatible with
Linux.
* FreeBSD provides the MAP_EXCL flag that has to be used in combination
with MAP_FIXED. It returns EINVAL if the requested range already
contains existing mappings. This is directly analogous to the O_EXCL
flag in the open () call.
* DragonFly BSD, NetBSD, and OpenBSD provide MAP_TRYFIXED, but with
different semantics. DragonFly BSD returns ENOMEM if the requested
range already contains existing mappings. NetBSD does not return an
error, but instead creates the mapping at a different address if the
requested range contains mappings. OpenBSD behaves the same, but also
notes that this is the default behavior even without MAP_TRYFIXED
(which is the case on the Hurd too).
Since the Hurd leans closer to the BSD side, add MAP_EXCL as the primary
API to request the behavior of not replacing existing mappings. Declare
MAP_FIXED_NOREPLACE and MAP_TRYFIXED as aliases of (MAP_FIXED|MAP_EXCL),
so any existing software that checks for either of those macros will
pick them up automatically. For compatibility with Linux, return EEXIST
if a mapping already exists.
Signed-off-by: Sergey Bugaev <bugaevc@gmail.com>
Message-Id: <20230625231751.404120-5-bugaevc@gmail.com>
Zero address passed to mmap () typically means the caller doesn't have
any specific preferred address. Not so if MAP_FIXED is passed: in this
case 0 means literal 0. Fix this case to pass anywhere = 0 into vm_map.
Also add some documentation.
Signed-off-by: Sergey Bugaev <bugaevc@gmail.com>
Message-Id: <20230625231751.404120-4-bugaevc@gmail.com>
Only call vm_deallocate when we do have the old buffer, and check for
unexpected errors.
Spotted while debugging a msgids/readdir issue on x86_64-gnu.
Signed-off-by: Sergey Bugaev <bugaevc@gmail.com>
Message-Id: <20230625231751.404120-3-bugaevc@gmail.com>
The rest of the heap (backed by individual pages) is already mapped RW.
Mapping these pages RWX presents a security hazard.
Also, in another branch memory gets allocated using vm_allocate, which
sets memory protection to VM_PROT_DEFAULT (which is RW). The mismatch
between protections prevents Mach from coalescing the VM map entries.
Signed-off-by: Sergey Bugaev <bugaevc@gmail.com>
Message-Id: <20230625231751.404120-2-bugaevc@gmail.com>
Instead of trying to allocate a thread stack at a specific address,
looping over the address space, just set the ANYWHERE flag in
vm_allocate (). The previous behavior:
- defeats ASLR (for Mach versions that support ASLR),
- is particularly slow if the lower 4 GB of the address space are mapped
inaccessible, as we're planning to do on 64-bit Hurd,
- is just silly.
Signed-off-by: Sergey Bugaev <bugaevc@gmail.com>
Message-Id: <20230625231751.404120-1-bugaevc@gmail.com>
This follows 1d44530a5b ("string: strerror must not return NULL (bug 30555)"):
«
For strerror, this fixes commit 28aff04781 ("string:
Implement strerror in terms of strerror_l"). This commit avoids
returning NULL for strerror_l as well, although POSIX allows this
behavior for strerror_l.
»
The first segment in a shared library may be read-only, not executable.
To support LD_PREFER_MAP_32BIT_EXEC on such shared libraries, we also
check MAP_DENYWRITE to decide if MAP_32BIT should be passed to mmap.
Normally the first segment is mapped with MAP_COPY, which is defined
as (MAP_PRIVATE | MAP_DENYWRITE). But if the segment alignment is
greater than the page size, MAP_COPY isn't used to allocate enough
space to ensure that the segment can be properly aligned. Map the
first segment with MAP_COPY in this case to fix BZ #30452.
Optimised implementations for single and double precision, Advanced
SIMD and SVE, copied from Arm Optimized Routines.
As previously, data tables are used via a barrier to prevent
overly aggressive constant inlining. Special-case handlers are
marked NOINLINE to avoid incurring the penalty of switching call
standards unnecessarily.
Reviewed-by: Szabolcs Nagy <szabolcs.nagy@arm.com>
Optimised implementations for single and double precision, Advanced
SIMD and SVE, copied from Arm Optimized Routines. Log lookup table
added as HIDDEN symbol to allow it to be shared between AdvSIMD and
SVE variants.
As previously, data tables are used via a barrier to prevent
overly aggressive constant inlining. Special-case handlers are
marked NOINLINE to avoid incurring the penalty of switching call
standards unnecessarily.
Reviewed-by: Szabolcs Nagy <szabolcs.nagy@arm.com>
Optimised implementations for single and double precision, Advanced
SIMD and SVE, copied from Arm Optimized Routines.
As previously, data tables are used via a barrier to prevent
overly aggressive constant inlining. Special-case handlers are
marked NOINLINE to avoid incurring the penalty of switching call
standards unnecessarily.
Reviewed-by: Szabolcs Nagy <szabolcs.nagy@arm.com>
Replace the loop-over-scalar placeholder routines with optimised
implementations from Arm Optimized Routines (AOR).
Also add some headers containing utilities for aarch64 libmvec
routines, and update libm-test-ulps.
Data tables for new routines are used via a pointer with a
barrier on it, in order to prevent overly aggressive constant
inlining in GCC. This allows a single adrp, combined with offset
loads, to be used for every constant in the table.
Special-case handlers are marked NOINLINE in order to confine the
save/restore overhead of switching from vector to normal calling
standard. This way we only incur the extra memory access in the
exceptional cases. NOINLINE definitions have been moved to
math_private.h in order to reduce duplication.
AOR exposes a config option, WANT_SIMD_EXCEPT, to enable
selective masking (and later fixing up) of invalid lanes, in
order to trigger fp exceptions correctly (AdvSIMD only). This is
tested and maintained in AOR, however it is configured off at
source level here for performance reasons. We keep the
WANT_SIMD_EXCEPT blocks in routine sources to greatly simplify
the upstreaming process from AOR to glibc.
Reviewed-by: Szabolcs Nagy <szabolcs.nagy@arm.com>
Linux 6.4 adds the riscv_hwprobe syscall on riscv and enables
memfd_secret on s390. Update syscall-names.list and regenerate the
arch-syscall.h headers with build-many-glibcs.py update-syscalls.
Tested with build-many-glibcs.py.
Trying to mount procfs can fail due multiples reasons: proc is locked
due the container configuration, mount syscall is filtered by a
Linux Secuirty Module, or any other security or hardening mechanism
that Linux might eventually add.
The tests does require a new procfs without binding to parent, and
to fully fix it would require to change how the container was created
(which is out of the scope of the test itself). Instead of trying to
foresee any possible scenario, if procfs can not be mount fail with
unsupported.
Checked on aarch64-linux-gnu.
Reviewed-by: Siddhesh Poyarekar <siddhesh@sourceware.org>
The tst-ttyname-direct.c checks the ttyname with procfs mounted in
bind mode (MS_BIND|MS_REC), while tst-ttyname-namespace.c checks
with procfs mount with MS_NOSUID|MS_NOEXEC|MS_NODEV in a new
namespace.
Checked on x86_64-linux-gnu and aarch64-linux-gnu.
Reviewed-by: Siddhesh Poyarekar <siddhesh@sourceware.org>
These files could be useful to any port that wants to use ld.so.cache.
Signed-off-by: Sergey Bugaev <bugaevc@gmail.com>
Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
Few tests needed to properly check for asprintf and system calls return
values with _FORTIFY_SOURCE enabled.
Reviewed-by: Siddhesh Poyarekar <siddhesh@sourceware.org>
The fread routine return value needs to be checked when fortification
is enabled, hence use xfread helper.
Reviewed-by: Siddhesh Poyarekar <siddhesh@sourceware.org>
On i386 and x86_64, for libc.a specifically, __mempcpy_chk calls
mempcpy which leads POSIX routines to call non-POSIX mempcpy indirectly.
This leads the linknamespace test to fail when glibc is built with
__FORTIFY_SOURCE=3.
Since calling mempcpy doesn't bring any benefit for libc.a, directly
call __mempcpy instead.
Reviewed-by: Siddhesh Poyarekar <siddhesh@sourceware.org>
Replace alloca with a scratch_buffer to avoid potential stack overflows.
Checked on i686-gnu and x86_64-linux-gnu
Message-Id: <20230619144334.2902429-1-josimmon@redhat.com>
There is a potential memory leak for large writes due to writev being a
"shall occur" cancellation point. Add back the cleanup handler removed
in cf30aa43a5.
Checked on i686-gnu and x86_64-linux-gnu.
Message-Id: <20230619143842.2901522-1-josimmon@redhat.com>
With fortification enabled, read calls return result needs to be checked,
has it gets the __wur macro enabled.
Note on read call removal from sysdeps/pthread/tst-cancel20.c and
sysdeps/pthread/tst-cancel21.c:
It is assumed that this second read call was there to overcome the race
condition between pipe closure and thread cancellation that could happen
in the original code. Since this race condition got fixed by
d0e3ffb7a5 the second call seems
superfluous. Hence, instead of checking for the return value of read, it
looks reasonable to simply remove it.
Reviewed-by: Siddhesh Poyarekar <siddhesh@sourceware.org>
Use a scratch_buffer rather than alloca to avoid potential stack
overflows.
Checked on i686-gnu and x86_64-linux-gnu
Message-Id: <20230608155844.976554-1-josimmon@redhat.com>
These functions are about to be added to POSIX, under Austin Group
issue 986.
The fortified strlcat implementation does not raise SIGABRT if the
destination buffer does not contain a null terminator, it just
inherits the non-failing regular strlcat behavior.
Reviewed-by: Siddhesh Poyarekar <siddhesh@sourceware.org>
With fortification enabled, fgets calls return result needs to be checked,
has it gets the __wur macro enabled.
Reviewed-by: Siddhesh Poyarekar <siddhesh@sourceware.org>
Different systems prefer a different divisors.
From benchmarks[1] so far the following divisors have been found:
ICX : 2
SKX : 2
BWD : 8
For Intel, we are generalizing that BWD and older prefers 8 as a
divisor, and SKL and newer prefers 2. This number can be further tuned
as benchmarks are run.
[1]: https://github.com/goldsteinn/memcpy-nt-benchmarks
Reviewed-by: DJ Delorie <dj@redhat.com>
This patch should have no affect on existing functionality.
The current code, which has a single switch for model detection and
setting prefered features, is difficult to follow/extend. The cases
use magic numbers and many microarchitectures are missing. This makes
it difficult to reason about what is implemented so far and/or
how/where to add support for new features.
This patch splits the model detection and preference setting stages so
that CPU preferences can be set based on a complete list of available
microarchitectures, rather than based on model magic numbers.
Reviewed-by: DJ Delorie <dj@redhat.com>
Current `non_temporal_threshold` set to roughly '3/4 * sizeof_L3 /
ncores_per_socket'. This patch updates that value to roughly
'sizeof_L3 / 4`
The original value (specifically dividing the `ncores_per_socket`) was
done to limit the amount of other threads' data a `memcpy`/`memset`
could evict.
Dividing by 'ncores_per_socket', however leads to exceedingly low
non-temporal thresholds and leads to using non-temporal stores in
cases where REP MOVSB is multiple times faster.
Furthermore, non-temporal stores are written directly to main memory
so using it at a size much smaller than L3 can place soon to be
accessed data much further away than it otherwise could be. As well,
modern machines are able to detect streaming patterns (especially if
REP MOVSB is used) and provide LRU hints to the memory subsystem. This
in affect caps the total amount of eviction at 1/cache_associativity,
far below meaningfully thrashing the entire cache.
As best I can tell, the benchmarks that lead this small threshold
where done comparing non-temporal stores versus standard cacheable
stores. A better comparison (linked below) is to be REP MOVSB which,
on the measure systems, is nearly 2x faster than non-temporal stores
at the low-end of the previous threshold, and within 10% for over
100MB copies (well past even the current threshold). In cases with a
low number of threads competing for bandwidth, REP MOVSB is ~2x faster
up to `sizeof_L3`.
The divisor of `4` is a somewhat arbitrary value. From benchmarks it
seems Skylake and Icelake both prefer a divisor of `2`, but older CPUs
such as Broadwell prefer something closer to `8`. This patch is meant
to be followed up by another one to make the divisor cpu-specific, but
in the meantime (and for easier backporting), this patch settles on
`4` as a middle-ground.
Benchmarks comparing non-temporal stores, REP MOVSB, and cacheable
stores where done using:
https://github.com/goldsteinn/memcpy-nt-benchmarks
Sheets results (also available in pdf on the github):
https://docs.google.com/spreadsheets/d/e/2PACX-1vS183r0rW_jRX6tG_E90m9qVuFiMbRIJvi5VAE8yYOvEOIEEc3aSNuEsrFbuXw5c3nGboxMmrupZD7K/pubhtml
Reviewed-by: DJ Delorie <dj@redhat.com>
Reviewed-by: Carlos O'Donell <carlos@redhat.com>
Container management default seccomp filter [1] only accepts
personality(2) with PER_LINUX, (0x0), UNAME26 (0x20000),
PER_LINUX32 (0x8), UNAME26 | PER_LINUX32, and 0xffffffff (to query
current personality)
Although the documentation only state it is blocked to prevent
'enabling BSD emulation' (PER_BSD, not implemented by Linux), checking
on repository log the real reason is to block ASLR disable flag
(ADDR_NO_RANDOMIZE) and other poorly support emulations.
So handle EPERM and fail as UNSUPPORTED if we can really check for
BZ#19408.
Checked on aarch64-linux-gnu.
[1] https://github.com/moby/moby/blob/master/profiles/seccomp/default.json
Reviewed-by: Florian Weimer <fweimer@redhat.com>
Since the area of the user's stack we use for the registers dump (and
otherwise as __sigreturn2's stack) can and does overlap the sigcontext,
we have to be very careful about the order of loads and stores that we
do. In particular we have to load sc_reply_port before we start
clobbering the sigcontext.
Signed-off-by: Sergey Bugaev <bugaevc@gmail.com>
epoll_pwait2(2)'s second argument should be nonnull. We're going to add
__nonnull to the prototype, so let's fix the test accordingly. We can
use a dummy variable to avoid passing NULL.
Reported-by: Adhemerval Zanella Netto <adhemerval.zanella@linaro.org>
Signed-off-by: Alejandro Colomar <alx@kernel.org>
With fortification enabled, few function calls return result need to be
checked, has they get the __wur macro enabled.
Reviewed-by: Siddhesh Poyarekar <siddhesh@sourceware.org>
Since the assembly source file with -evex suffix should use YMM registers,
not ZMM registers, include x86-evex256-vecs.h by default to use YMM
registers in memcmpeq-evex.S
Reviewed-by: Noah Goldstein <goldstein.w.n@gmail.com>
Different than other 64 bit architectures, powerpc64 defines the
LFS POSIX lock constants with values similar to 32 ABI, which
are meant to be used with fcntl64 syscall. Since powerpc64 kABI
does not have fcntl, the constants are adjusted with the
FCNTL_ADJUST_CMD macro.
The 4d0fe291ae changed the logic of generic constants
LFS value are equal to the default values; which is now wrong
for powerpc64.
Fix the value by explicit define the previous glibc constants
(powerpc64 does not need to use the 32 kABI value, but it simplifies
the FCNTL_ADJUST_CMD which should be kept as compatibility).
Checked on powerpc64-linux-gnu and powerpc-linux-gnu.
For architecture with default 64 bit time_t support, the kernel
does not provide LFS and non-LFS values for F_GETLK, F_GETLK, and
F_GETLK (the default value used for 64 bit architecture are used).
This is might be considered an ABI break, but the currenct exported
values is bogus anyway.
The POSIX lockf is not affected since it is aliased to lockf64,
which already uses the LFS values.
Checked on i686-linux-gnu and the new tests on a riscv32.
Reviewed-by: Carlos O'Donell <carlos@redhat.com>
The LoongArch glibc was using the value of the SHMLBA macro from common code,
which is __getpagesize() (16k), but this was inconsistent with the value of
the SHMLBA macro in the kernel, which is SZ_64K (64k). This caused several
shmat-related tests in LTP (Linux Test Project) to fail. This commit fixes
the issue by ensuring that the glibc's SHMLBA macro value matches the value
used in the kernel like other architectures.
Use a scratch_buffer rather than either alloca or malloc to reduce the
possibility of a stack overflow.
Suggested-by: Adhemerval Zanella Netto <adhemerval.zanella@linaro.org>
Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
If `non_temporal_threshold` is below `minimum_non_temporal_threshold`,
it almost certainly means we failed to read the systems cache info.
In this case, rather than defaulting the minimum correct value, we
should default to a value that gets at least reasonable
performance. 64MB is chosen conservatively to be at the very high
end. This should never cause non-temporal stores when, if we had read
cache info, we wouldn't have otherwise.
Reviewed-by: Florian Weimer <fweimer@redhat.com>
Linux 6.3 adds new constants MFD_NOEXEC_SEAL and MFD_EXEC. Add these
to bits/mman-shared.h (conditional on MFD_NOEXEC_SEAL not already
being defined, similar to the existing conditional on the older MFD_*
macros).
Tested for x86_64.
All fixes are in comments, so the binaries should be identical
before/after this commit, but I can't verify this.
Reviewed-by: Rajalakshmi Srinivasaraghavan <rajis@linux.ibm.com>
Applying this commit results in a bit-identical rebuild of
mathvec/libmvec.so.1 (which is the only binary that gets rebuilt).
Reviewed-by: Noah Goldstein <goldstein.w.n@gmail.com>
We do not want mach_i386.h to get installed into machine/, but into
i386/ or x86_64/ depending where mach_i386.defs was found, i.e.
according to 32/64 bitness.
Some of the s390-specific configure checks are using compile and
link configure tests. Now use only compile tests as the link
tests fails when e.g. bootstrapping a cross-toolchain due to
missing crt-files/libc.so. This is achieved by using
AC_COMPILE_IFELSE in configure.ac file.
This is observable e.g. when using buildroot which builds glibc
only once or the build-many-glibcs.py script. Note that the latter
one is building glibc twice in the compilers-step (configure-checks
fails) and in the glibcs-step (configure-checks succeed).
Note, that the s390 specific configure tests for static PIE have to
link an executable to test binutils support. Thus we can't fix
those tests.
The __hurd_fail () inline function is the dedicated, idiomatic way of
reporting errors in the Hurd part of glibc. Not only is it more concise
than '{ errno = err; return -1; }', it is since commit
6639cc1002
"hurd: Mark error functions as __COLD" marked with the cold attribute,
telling the compiler that this codepath is unlikely to be executed.
In one case, use __hurd_dfail () over the plain __hurd_fail ().
Signed-off-by: Sergey Bugaev <bugaevc@gmail.com>
Message-Id: <20230520115531.3911877-1-bugaevc@gmail.com>
Create a private hidden __hurd_thread_self alias, and use that one.
Fixes 2f8ecb58a5
"hurd: Fix x86_64 _hurd_tls_fork" and
c7fcce38c8
"hurd: Make sure to not use tcb->self"
Reported-by: Joseph Myers <joseph@codesourcery.com>
Signed-off-by: Sergey Bugaev <bugaevc@gmail.com>
Linux 6.3 adds six HWCAP2_SME* constants for AArch64; add them to the
corresponding bits/hwcap.h in glibc.
Tested with build-many-glibcs.py for aarch64-linux-gnu.
strlen, which is another ifunc-selected function, is invoked during
early static executable startup if the argv arrives from the exec
server. Make it not crash.
Checked on x86_64-gnu: statically linked executables launched after the
exec server is up now start up successfully.
Signed-off-by: Sergey Bugaev <bugaevc@gmail.com>
Message-Id: <20230517191436.73636-10-bugaevc@gmail.com>
On x86_64, we have to pass function arguments in registers, not on the
stack. We also have to align the stack pointer in a specific way. Since
sharing the logic with i386 does not bring much benefit, split the file
back into i386- and x86_64-specific versions, and fix the x86_64 version
to set up the thread properly.
Bonus: i386 keeps doing the extra RPC inside __thread_set_pcsptp to
fetch the state of the thread before setting it; but x86_64 no lnoger
does that.
Checked on x86_64-gnu and i686-gnu.
Fixes be6d002ca2
"hurd: Set up the basic tree for x86_64-gnu"
Signed-off-by: Sergey Bugaev <bugaevc@gmail.com>
Message-Id: <20230517191436.73636-9-bugaevc@gmail.com>
It is illegal to call thread_get_state () on mach_thread_self (), so
this codepath cannot be used as-is to fork the calling thread's TLS.
Fortunately we can use THREAD_SELF (aka %fs:0x0) to find out the value
of our fs_base without calling into the kernel.
Fixes: f6cf701efc
"hurd: Implement TLS for x86_64"
Checked on x86_64-gnu: fork () now works!
Signed-off-by: Sergey Bugaev <bugaevc@gmail.com>
Message-Id: <20230517191436.73636-8-bugaevc@gmail.com>
Unlike sigstate->thread, tcb->self did not hold a Mach port reference on
the thread port it names. This means that the port can be deallocated,
and the name reused for something else, without anyone noticing. Using
tcb->self will then lead to port use-after-free.
Fortunately nothing was accessing tcb->self, other than it being
intially set to then-valid thread port name upon TCB initialization. To
assert that this keeps being the case without altering TCB layout,
rename self -> self_do_not_use, and stop initializing it.
Also, do not (re-)allocate a whole separate and unused stack for the
main thread, and just exit __pthread_setup early in this case.
Found upon attempting to use tcb->self and getting unexpected crashes.
Signed-off-by: Sergey Bugaev <bugaevc@gmail.com>
Message-Id: <20230517191436.73636-7-bugaevc@gmail.com>
...instead of mach_setup_thread (), which is unsuitable for setting up
function calls.
Checked on x86_64-gnu: the signal thread no longer crashes upon trying
to process a message.
Signed-off-by: Sergey Bugaev <bugaevc@gmail.com>
Message-Id: <20230517191436.73636-6-bugaevc@gmail.com>
The existing two macros, MACHINE_THREAD_STATE_SET_PC and
MACHINE_THREAD_STATE_SET_SP, can be used to set program counter and the
stack pointer registers in a machine-specific thread state structure.
Useful as it is, this may not be enough to set up the thread to make a
function call, because the machine-specific ABI may impose additional
requirements. In particular, x86_64 ABI requires that upon function
entry, the stack pointer is 8 less than 16-byte aligned (sp & 15 == 8).
To deal with this, introduce a new macro,
MACHINE_THREAD_STATE_SETUP_CALL (), which sets both stack and
instruction pointers, and also applies any machine-specific requirements
to make a valid function call. The default implementation simply
forwards to MACHINE_THREAD_STATE_SET_PC and MACHINE_THREAD_STATE_SET_SP,
but on x86_64 we additionally align the stack pointer.
Signed-off-by: Sergey Bugaev <bugaevc@gmail.com>
Message-Id: <20230517191436.73636-3-bugaevc@gmail.com>
This hasn't caused any problems yet but we are passing a pointer to struct
task_thread_times_info which can cause problems if we populate over the
existing size of the struct.
Message-Id: <ZGRDDNcOM2hA3CuT@jupiter.tail36e24.ts.net>
This patch updates the kernel version in the tests tst-mman-consts.py,
tst-mount-consts.py and tst-pidfd-consts.py to 6.3. (There are no new
constants covered by these tests in 6.3 that need any other header
changes.)
Tested with build-many-glibcs.py.
So I was able to reproduce the hangs in the original source, and debug
it, and fix it. In doing so, I realized that we can't use anything
complex to trigger the thread because that "anything" might also cause
the expected segfault and force everything out of sync again.
Here's what I ended up with, and it doesn't seem to hang where the
original one hung quite often (in a tight while..end loop). The key
changes are:
1. Calls to futex are error checked, with retries, to ensure that the
futexes are actually doing what they're supposed to be doing. In the
original code, nearly every futex call returned an error.
2. The main loop has checks for whether the thread ran or not, and
"unlocks" the thread if it didn't (this is how the original source
hangs).
Note: the usleep() is not for timing purposes, but just to give the
kernel an excuse to run the other thread at that time. The test will
not hang without it, but is more likely to test the right bugfix
if the usleep() is present.
The real i386_thread_state Mach structure has an alignment of 8 on
x86_64. However, in struct sigcontext, the compiler was packing sc_gs
(which is the first member of sc_i386_thread_state) into the same 8-byte
slot as sc_error; this resulted in the rest of sc_i386_thread_state
members having wrong offsets relative to each other, and the overall
sc_i386_thread_state layout mismatching that of i386_thread_state.
Fix this by explicitly adding the required padding members, and
statically asserting that this results in the desired alignment.
The same goes for sc_i386_float_state.
Checked on x86_64-gnu.
Signed-off-by: Sergey Bugaev <bugaevc@gmail.com>
Message-Id: <20230515083323.1358039-4-bugaevc@gmail.com>
sizeof (*stackframe) appears to be divisible by 16, but we should not
rely on that. So make sure to leave enough space for the stackframe
first, and then align the final pointer at 16 bytes.
Checked on x86_64-gnu.
Signed-off-by: Sergey Bugaev <bugaevc@gmail.com>
Message-Id: <20230515083323.1358039-3-bugaevc@gmail.com>
Fixes 60f9bf9746
"hurd: Port trampoline.c to x86_64"
Checked on x86_64-gnu.
Reported-by: Bruno Haible <bruno@clisp.org>
Signed-off-by: Sergey Bugaev <bugaevc@gmail.com>
Message-Id: <20230515083323.1358039-2-bugaevc@gmail.com>
Reflow Makefile.
Sort using scripts/sort-makefile-lines.py.
No code generation changes observed in binary artifacts.
No regressions on x86_64 and i686.
Linux 6.3 has no new syscalls. Update the version number in
syscall-names.list to reflect that it is still current for 6.3.
Tested with build-many-glibcs.py.
While mach/kern_return.h happens to pull mach/machine/kern_return.h,
mach/machine/boolean.h, and mach/machine/vm_types.h (and realpath-ing them
exposes the machine-specific machine symlink content), those headers do not
actually define anything machine-specific for the content of errno.h.
So we can just rule out these machine-specific from the dependency
comment.
We already did the same change for Hurd
(https://git.savannah.gnu.org/cgit/hurd/hurd.git/commit/?id=ef5924402864ef049f40a39e73967628583bc1a4)
Due to MiG requiring the subsystem to be defined early in order to know the
size of a port, this was causing a division by zero error during ./configure.
We could have just move subsystem to the top of the snippet, however it is
simpler to just remove the check given that we have no plans to use some other
MiG anyway.
HAVE_MIG_RETCODE is removed completely since this will be a no-op either
way (compiling against old Hurd headers will work the same, new Hurd
headers will result in the same stubs since retcode is a no-op).
Message-Id: <ZFspor91aoMwbh9T@jupiter.tail36e24.ts.net>
This patch redirects the error functions to the appropriate
longdouble variants which enables the compiler to optimize
for the abi ieeelongdouble.
Signed-off-by: Sachin Monga <smonga@linux.ibm.com>
Reflow all long lines adding comment terminators.
Sort all reflowed text using scripts/sort-makefile-lines.py.
No code generation changes observed in binary artifacts.
No regressions on x86_64 and i686.
Reviewed-by: Siddhesh Poyarekar <siddhesh@sourceware.org>
Summary of changes:
- Use BAD_TYPECHECK to perform type checking in a cleaner way.
BAD_TYPECHECK is moved into sysdeps/mach/rpc.h to avoid duplication.
- Remove assertions for mach_msg_type_t since those won't work for
x86_64.
- Update message structs to use mach_msg_type_t directly.
- Use designated initializers.
Message-Id: <ZFa+roan3ioo0ONM@jupiter.tail36e24.ts.net>
