Commit Graph

15582 Commits

Author SHA1 Message Date
H.J. Lu
aa528a579b <sys/platform/x86.h>: Add LASS support
Add Linear Address Space Separation (LASS) support to <sys/platform/x86.h>.
Reviewed-by: Noah Goldstein <goldstein.w.n@gmail.com>
2023-04-05 14:46:10 -07:00
H.J. Lu
231bf916ce <sys/platform/x86.h>: Add RAO-INT support
Add RAO-INT support to <sys/platform/x86.h>.
Reviewed-by: Noah Goldstein <goldstein.w.n@gmail.com>
2023-04-05 14:46:10 -07:00
H.J. Lu
fb90dc8513 <sys/platform/x86.h>: Add LBR support
Add architectural LBR support to <sys/platform/x86.h>.
Reviewed-by: Noah Goldstein <goldstein.w.n@gmail.com>
2023-04-05 14:46:10 -07:00
H.J. Lu
f47b7d96fb <sys/platform/x86.h>: Add RTM_FORCE_ABORT support
Add RTM_FORCE_ABORT support to <sys/platform/x86.h>.
Reviewed-by: Noah Goldstein <goldstein.w.n@gmail.com>
2023-04-05 14:46:10 -07:00
H.J. Lu
f6790a489d <sys/platform/x86.h>: Add SGX-KEYS support
Add SGX-KEYS support to <sys/platform/x86.h>.
Reviewed-by: Noah Goldstein <goldstein.w.n@gmail.com>
2023-04-05 14:46:10 -07:00
H.J. Lu
09cc5fee21 <sys/platform/x86.h>: Add BUS_LOCK_DETECT support
Add Bus lock debug exceptions (BUS_LOCK_DETECT) support to
<sys/platform/x86.h>.
Reviewed-by: Noah Goldstein <goldstein.w.n@gmail.com>
2023-04-05 14:46:10 -07:00
H.J. Lu
8c8e391166 <sys/platform/x86.h>: Add LA57 support
Add 57-bit linear addresses and five-level paging (LA57) support to
<sys/platform/x86.h>.
Reviewed-by: Noah Goldstein <goldstein.w.n@gmail.com>
2023-04-05 14:46:10 -07:00
H.J. Lu
2d8c590a5e <bits/platform/x86.h>: Rename to x86_cpu_INDEX_7_ECX_15
Rename x86_cpu_INDEX_7_ECX_1 to x86_cpu_INDEX_7_ECX_15 for the unused bit
15 in ECX from CPUID with EAX == 0x7 and ECX == 0.
Reviewed-by: Noah Goldstein <goldstein.w.n@gmail.com>
2023-04-05 14:46:10 -07:00
John David Anglin
c4468cd399 hppa: Update struct __pthread_rwlock_arch_t comment.
Signed-off-by: John David Anglin <dave.anglin@bell.net>
2023-04-05 18:54:47 +00:00
John David Anglin
e9327e8584 hppa: Revise __TIMESIZE define to use __WORDSIZE
Handle both 32 and 64-bit ABIs.

Signed-off-by: John David Anglin <dave.anglin@bell.net>
2023-04-05 18:35:38 +00:00
Guy-Fleury Iteriteka
5476f8cd2e htl: move pthread_self info libc.
Signed-off-by: Guy-Fleury Iteriteka <gfleury@disroot.org>
Message-Id: <20230318095826.1125734-4-gfleury@disroot.org>
2023-04-05 01:26:36 +02:00
Guy-Fleury Iteriteka
f987e9b7a3 htl: move ___pthread_self into libc.
sysdeps/mach/hurd/htl/pt-pthread_self.c: New file.
htl/Makefile: .. Add it to libc routine.
sysdeps/mach/hurd/htl/pt-sysdep.c(__pthread_self): Remove it.
sysdeps/mach/hurd/htl/pt-sysdep.h(__pthread_self): Add hidden propertie.
htl/Versions(__pthread_self) Version it as private symbol.

Signed-off-by: Guy-Fleury Iteriteka <gfleury@disroot.org>
Message-Id: <20230318095826.1125734-3-gfleury@disroot.org>
2023-04-05 01:26:34 +02:00
Andreas Schwab
856bab7717 x86/dl-cacheinfo: remove unsused parameter from handle_amd
Also replace an unreachable assert with __builtin_unreachable.
2023-04-04 16:16:21 +02:00
Adhemerval Zanella
59db5735e6 powerpc: Disable stack protector in early static initialization
Similar to fb95c31638, also disable
for string-ppc64.c (pulled on rltd as the default string
implementation).

Checked on powerpc64-linux-gnu.
2023-04-03 17:42:08 -03:00
Adhemerval Zanella
370da8a121 nptl: Fix tst-cancel30 on sparc64
As indicated by sparc kernel-features.h, even though sparc64 defines
__NR_pause,  it is not supported (ENOSYS).  Always use ppoll or the
64 bit time_t variant instead.
2023-04-03 17:41:59 -03:00
Adhemerval Zanella Netto
16439f419b math: Remove the error handling wrapper from fmod and fmodf
The error handling is moved to sysdeps/ieee754 version with no SVID
support.  The compatibility symbol versions still use the wrapper
with SVID error handling around the new code.  There is no new symbol
version nor compatibility code on !LIBM_SVID_COMPAT targets
(e.g. riscv).

The ia64 is unchanged, since it still uses the arch specific
__libm_error_region on its implementation.  For both i686 and m68k,
which provive arch specific implementation, wrappers are added so
no new symbol are added (which would require to change the
implementations).

It shows an small improvement, the results for fmod:

  Architecture     | Input           | master   | patch
  -----------------|-----------------|----------|--------
  x86_64 (Ryzen 9) | subnormals      | 12.5049  | 9.40992
  x86_64 (Ryzen 9) | normal          | 296.939  | 296.738
  x86_64 (Ryzen 9) | close-exponents | 16.0244  | 13.119
  aarch64 (N1)     | subnormal       | 6.81778  | 4.33313
  aarch64 (N1)     | normal          | 155.620  | 152.915
  aarch64 (N1)     | close-exponents | 8.21306  | 5.76138
  armhf (N1)       | subnormal       | 15.1083  | 14.5746
  armhf (N1)       | normal          | 244.833  | 241.738
  armhf (N1)       | close-exponents | 21.8182  | 22.457

Checked on x86_64-linux-gnu, i686-linux-gnu, and aarch64-linux-gnu.
Reviewed-by: Wilco Dijkstra  <Wilco.Dijkstra@arm.com>
2023-04-03 16:45:27 -03:00
Adhemerval Zanella Netto
cf9cf33199 math: Improve fmodf
This uses a new algorithm similar to already proposed earlier [1].
With x = mx * 2^ex and y = my * 2^ey (mx, my, ex, ey being integers),
the simplest implementation is:

   mx * 2^ex == 2 * mx * 2^(ex - 1)

   while (ex > ey)
     {
       mx *= 2;
       --ex;
       mx %= my;
     }

With mx/my being mantissa of double floating pointer, on each step the
argument reduction can be improved 8 (which is sizeof of uint32_t minus
MANTISSA_WIDTH plus the signal bit):

   while (ex > ey)
     {
       mx << 8;
       ex -= 8;
       mx %= my;
     }  */

The implementation uses builtin clz and ctz, along with shifts to
convert hx/hy back to doubles.  Different than the original patch,
this path assume modulo/divide operation is slow, so use multiplication
with invert values.

I see the following performance improvements using fmod benchtests
(result only show the 'mean' result):

  Architecture     | Input           | master   | patch
  -----------------|-----------------|----------|--------
  x86_64 (Ryzen 9) | subnormals      | 17.2549  | 12.0318
  x86_64 (Ryzen 9) | normal          | 85.4096  | 49.9641
  x86_64 (Ryzen 9) | close-exponents | 19.1072  | 15.8224
  aarch64 (N1)     | subnormal       | 10.2182  | 6.81778
  aarch64 (N1)     | normal          | 60.0616  | 20.3667
  aarch64 (N1)     | close-exponents | 11.5256  | 8.39685

I also see similar improvements on arm-linux-gnueabihf when running on
the N1 aarch64 chips, where it a lot of soft-fp implementation (for
modulo, and multiplication):

  Architecture     | Input           | master   | patch
  -----------------|-----------------|----------|--------
  armhf (N1)       | subnormal       | 11.6662  | 10.8955
  armhf (N1)       | normal          | 69.2759  | 34.1524
  armhf (N1)       | close-exponents | 13.6472  | 18.2131

Instead of using the math_private.h definitions, I used the
math_config.h instead which is used on newer math implementations.

Co-authored-by: kirill <kirill.okhotnikov@gmail.com>

[1] https://sourceware.org/pipermail/libc-alpha/2020-November/119794.html
Reviewed-by: Wilco Dijkstra  <Wilco.Dijkstra@arm.com>
2023-04-03 16:45:18 -03:00
Adhemerval Zanella Netto
34b9f8bc17 math: Improve fmod
This uses a new algorithm similar to already proposed earlier [1].
With x = mx * 2^ex and y = my * 2^ey (mx, my, ex, ey being integers),
the simplest implementation is:

   mx * 2^ex == 2 * mx * 2^(ex - 1)

   while (ex > ey)
     {
       mx *= 2;
       --ex;
       mx %= my;
     }

With mx/my being mantissa of double floating pointer, on each step the
argument reduction can be improved 11 (which is sizeo of uint64_t minus
MANTISSA_WIDTH plus the signal bit):

   while (ex > ey)
     {
       mx << 11;
       ex -= 11;
       mx %= my;
     }  */

The implementation uses builtin clz and ctz, along with shifts to
convert hx/hy back to doubles.  Different than the original patch,
this path assume modulo/divide operation is slow, so use multiplication
with invert values.

I see the following performance improvements using fmod benchtests
(result only show the 'mean' result):

  Architecture     | Input           | master   | patch
  -----------------|-----------------|----------|--------
  x86_64 (Ryzen 9) | subnormals      | 19.1584  | 12.5049
  x86_64 (Ryzen 9) | normal          | 1016.51  | 296.939
  x86_64 (Ryzen 9) | close-exponents | 18.4428  | 16.0244
  aarch64 (N1)     | subnormal       | 11.153   | 6.81778
  aarch64 (N1)     | normal          | 528.649  | 155.62
  aarch64 (N1)     | close-exponents | 11.4517  | 8.21306

I also see similar improvements on arm-linux-gnueabihf when running on
the N1 aarch64 chips, where it a lot of soft-fp implementation (for
modulo, clz, ctz, and multiplication):

  Architecture     | Input           | master   | patch
  -----------------|-----------------|----------|--------
  armhf (N1)       | subnormal       | 15.908   | 15.1083
  armhf (N1)       | normal          | 837.525  | 244.833
  armhf (N1)       | close-exponents | 16.2111  | 21.8182

Instead of using the math_private.h definitions, I used the
math_config.h instead which is used on newer math implementations.

Co-authored-by: kirill <kirill.okhotnikov@gmail.com>

[1] https://sourceware.org/pipermail/libc-alpha/2020-November/119794.html
Reviewed-by: Wilco Dijkstra  <Wilco.Dijkstra@arm.com>
2023-04-03 16:36:24 -03:00
H.J. Lu
743113d42e x86: Set FSGSBASE to active if enabled by kernel
Linux kernel uses AT_HWCAP2 to indicate if FSGSBASE instructions are
enabled.  If the HWCAP2_FSGSBASE bit in AT_HWCAP2 is set, FSGSBASE
instructions can be used in user space.  Define dl_check_hwcap2 to set
the FSGSBASE feature to active on Linux when the HWCAP2_FSGSBASE bit is
set.

Add a test to verify that FSGSBASE is active on current kernels.
NB: This test will fail if the kernel doesn't set the HWCAP2_FSGSBASE
bit in AT_HWCAP2 while fsgsbase shows up in /proc/cpuinfo.
Reviewed-by: Florian Weimer <fweimer@redhat.com>
2023-04-03 11:36:48 -07:00
Florian Weimer
5d1ccdda7b x86_64: Fix asm constraints in feraiseexcept (bug 30305)
The divss instruction clobbers its first argument, and the constraints
need to reflect that.  Fortunately, with GCC 12, generated code does
not actually change, so there is no externally visible bug.

Suggested-by: Jakub Jelinek <jakub@redhat.com>
Reviewed-by: Noah Goldstein <goldstein.w.n@gmail.com>
2023-04-03 18:40:52 +02:00
Sergey Bugaev
17841fa7d4 hurd: Add vm_param.h for x86_64
Signed-off-by: Sergey Bugaev <bugaevc@gmail.com>
Message-Id: <20230319151017.531737-30-bugaevc@gmail.com>
2023-04-03 01:24:13 +02:00
Sergey Bugaev
20427b8f23 hurd: Implement _hurd_longjmp_thread_state for x86_64
Signed-off-by: Sergey Bugaev <bugaevc@gmail.com>
Message-Id: <20230319151017.531737-29-bugaevc@gmail.com>
2023-04-03 01:23:30 +02:00
Sergey Bugaev
e0bbae0062 htl: Implement thread_set_pcsptp for x86_64
Signed-off-by: Sergey Bugaev <bugaevc@gmail.com>
Message-Id: <20230319151017.531737-23-bugaevc@gmail.com>
2023-04-03 01:18:27 +02:00
Sergey Bugaev
8d873a4904 x86_64: Add rtld-stpncpy & rtld-strncpy
Just like the other existing rtld-str* files, this provides rtld with
usable versions of stpncpy and strncpy.

Signed-off-by: Sergey Bugaev <bugaevc@gmail.com>
Message-Id: <20230319151017.531737-22-bugaevc@gmail.com>
2023-04-03 01:17:56 +02:00
Sergey Bugaev
fb9e7f6732 htl: Add tcb-offsets.sym for x86_64
The source code is the same as sysdeps/i386/htl/tcb-offsets.sym, but of
course the produced tcb-offsets.h will be different.

Signed-off-by: Sergey Bugaev <bugaevc@gmail.com>
Message-Id: <20230319151017.531737-21-bugaevc@gmail.com>
2023-04-03 01:15:30 +02:00
Sergey Bugaev
d8b69e89d8 hurd: Move a couple of signal-related files to x86
These do not need any changes to be used on x86_64.

Signed-off-by: Sergey Bugaev <bugaevc@gmail.com>
Message-Id: <20230319151017.531737-20-bugaevc@gmail.com>
2023-04-03 01:14:51 +02:00
Sergey Bugaev
a1fbae7527 hurd: Use uintptr_t for register values in trampoline.c
This is more correct, if only because these fields are defined as having
the type unsigned int in the Mach headers, so casting them to a signed
int and then back is suboptimal.

Also, remove an extra reassignment of uesp -- this is another remnant of
the ecx kludge.

Signed-off-by: Sergey Bugaev <bugaevc@gmail.com>
Message-Id: <20230319151017.531737-16-bugaevc@gmail.com>
2023-04-03 01:13:28 +02:00
Sergey Bugaev
b43cb67457 hurd: Move rtld-strncpy-c.c out of mach/hurd/
There's nothing Mach- or Hurd-specific about it; any port that ends
up with rtld pulling in strncpy will need this.

Signed-off-by: Sergey Bugaev <bugaevc@gmail.com>
Message-Id: <20230319151017.531737-15-bugaevc@gmail.com>
2023-04-03 01:10:23 +02:00
Sergey Bugaev
0001a23f7a hurd: More 64-bit integer casting fixes
Signed-off-by: Sergey Bugaev <bugaevc@gmail.com>
Message-Id: <20230319151017.531737-13-bugaevc@gmail.com>
2023-04-03 01:03:06 +02:00
Sergey Bugaev
af2942cc62 mach, hurd: Drop __libc_lock_self0
This was used for the value of libc-lock's owner when TLS is not yet set
up, so THREAD_SELF can not be used. Since the value need not be anything
specific -- it just has to be non-NULL -- we can just use a plain
constant, such as (void *) 1, for this. This avoids accessing the symbol
through GOT, and exporting it from libc.so in the first place.

Signed-off-by: Sergey Bugaev <bugaevc@gmail.com>
Message-Id: <20230319151017.531737-12-bugaevc@gmail.com>
2023-04-03 01:02:44 +02:00
Sergey Bugaev
71232da3b3 hurd: Remove __hurd_threadvar_stack_{offset,mask}
Noone is or should be using __hurd_threadvar_stack_{offset,mask}, we
have proper TLS now. These two remaining variables are never set to
anything other than zero, so any code that would try to use them as
described would just dereference a zero pointer and crash. So remove
them entirely.

Signed-off-by: Sergey Bugaev <bugaevc@gmail.com>
Message-Id: <20230319151017.531737-6-bugaevc@gmail.com>
2023-04-03 00:53:25 +02:00
Adhemerval Zanella
113549d9fd Update arm libm-tests-ulps
For the next test from cf7ffdd8a5.
2023-03-30 10:50:50 -03:00
Andreas Schwab
0d83b349fa getlogin_r: fix missing fallback if loginuid is unset (bug 30235)
When /proc/self/loginuid is not set, we should still fall back to using
the traditional utmp lookup, instead of failing right away.
2023-03-30 13:58:27 +02:00
Adhemerval Zanella Netto
33237fe83d Remove --enable-tunables configure option
And make always supported.  The configure option was added on glibc 2.25
and some features require it (such as hwcap mask, huge pages support, and
lock elisition tuning).  It also simplifies the build permutations.

Changes from v1:
 * Remove glibc.rtld.dynamic_sort changes, it is orthogonal and needs
   more discussion.
 * Cleanup more code.
Reviewed-by: Siddhesh Poyarekar <siddhesh@sourceware.org>
2023-03-29 14:33:06 -03:00
Joe Simmons-Talbott
868506eb42 system: Add "--" after "-c" for sh (BZ #28519)
Prevent sh from interpreting a user string as shell options if it
starts with '-' or '+'.  Since the version of /bin/sh used for testing
system() is different from the full-fledged system /bin/sh add support
to it for handling "--" after "-c".  Add a testcase to ensure the
expected behavior.

Signed-off-by: Joe Simmons-Talbott <josimmon@redhat.com>
Reviewed-by: Adhemerval Zanella  <adhemerval.zanella@linaro.org>
2023-03-28 10:12:30 -03:00
caiyinyu
07dd75589e LoongArch: ldconfig: Add comments for using EF_LARCH_OBJABI_V1
We added Adhemerval Zanella's comment to explain the reason for
using EF_LARCH_OBJABI_V1.
2023-03-28 09:55:48 +08:00
Adhemerval Zanella Netto
f65ca70dea libio: Do not autogenerate stdio_lim.h
Instead define the required fields in system dependend files.  The only
system dependent definition is FILENAME_MAX, which should match POSIX
PATH_MAX, and it is obtained from either kernel UAPI or mach headers.
Currently set pre-defined value from current kernels.

It avoids a circular dependendy when including stdio.h in
gen-as-const-headers files.

Checked on x86_64-linux-gnu and i686-linux-gnu
Reviewed-by: Carlos O'Donell <carlos@redhat.com>
2023-03-27 13:57:55 -03:00
Adhemerval Zanella Netto
88677348b4 Move libc_freeres_ptrs and libc_subfreeres to hidden/weak functions
They are both used by __libc_freeres to free all library malloc
allocated resources to help tooling like mtrace or valgrind with
memory leak tracking.

The current scheme uses assembly markers and linker script entries
to consolidate the free routine function pointers in the RELRO segment
and to be freed buffers in BSS.

This patch changes it to use specific free functions for
libc_freeres_ptrs buffers and call the function pointer array directly
with call_function_static_weak.

It allows the removal of both the internal macros and the linker
script sections.

Checked on x86_64-linux-gnu, i686-linux-gnu, and aarch64-linux-gnu.
Reviewed-by: Carlos O'Donell <carlos@redhat.com>
2023-03-27 13:57:55 -03:00
Joe Ramsay
e4d336f1ac benchtests: Move libmvec benchtest inputs to benchtests directory
This allows other targets to use the same inputs for their own libmvec
microbenchmarks without having to duplicate them in their own
subdirectory.
Reviewed-by: Szabolcs Nagy <szabolcs.nagy@arm.com>
2023-03-27 17:04:03 +01:00
Xi Ruoyao
952b7630c7 LoongArch: ldconfig: Ignore EF_LARCH_OBJABI_V1 in shared objects
Binutils 2.40 sets EF_LARCH_OBJABI_V1 for shared objects:

    $ ld --version | head -n1
    GNU ld (GNU Binutils) 2.40
    $ echo 'int dummy;' > dummy.c
    $ cc dummy.c -shared
    $ readelf -h a.out | grep Flags
    Flags:                             0x43, DOUBLE-FLOAT, OBJ-v1

We need to ignore it in ldconfig or ldconfig will consider all shared
objects linked by Binutils 2.40 "unsupported".  Maybe we should stop
setting EF_LARCH_OBJABI_V1 for shared objects, but Binutils 2.40 is
already released and we cannot change it.
2023-03-27 16:57:56 +08:00
John David Anglin
ab991a3d1b hppa: Drop 16-byte pthread lock alignment
Linux threads were removed about 12 years ago and the current
nptl implementation only requires 4-byte alignment for pthread
locks.

The 16-byte alignment causes various issues. For example in
building ignition-msgs, we have:

/usr/include/google/protobuf/map.h:124:37: error: static assertion failed
  124 |   static_assert(alignof(value_type) <= 8, "");
      |                 ~~~~~~~~~~~~~~~~~~~~^~~~

This is caused by the 16-byte pthread lock alignment.

Signed-off-by: John David Anglin <dave.anglin@bell.net>
2023-03-26 21:16:22 +00:00
DJ Delorie
db9b47e9f9 x86: Don't check PREFETCHWT1 in tst-cpu-features-cpuinfo.c
Don't check PREFETCHWT1 against /proc/cpuinfo since kernel doesn't report
PREFETCHWT1 in /proc/cpuinfo.

Reviewed-by: Noah Goldstein <goldstein.w.n@gmail.com>
2023-03-21 17:49:49 -04:00
Pavel Kozlov
447273e0bf ARC: run child from the separate start block in __clone
For better debug experience use separate code block with extra
cfi_* directives to run child (same as in __clone3).

Reviewed-by: Adhemerval Zanella  <adhemerval.zanella@linaro.org>
2023-03-13 18:12:32 +04:00
Pavel Kozlov
3681cdb8f8 ARC: Add the clone3 wrapper
Use the clone3 wrapper on ARC. It doesn't care about stack alignment.
All callers should provide an aligned stack.
It follows the internal signature:

extern int clone3 (struct clone_args *__cl_args, size_t __size,
 int (*__func) (void *__arg), void *__arg);

Reviewed-by: Adhemerval Zanella  <adhemerval.zanella@linaro.org>
2023-03-13 18:12:32 +04:00
caiyinyu
90233f113c LoongArch: Add get_rounding_mode. 2023-03-13 09:20:42 +08:00
caiyinyu
f0d33cbdce LoongArch: Add support for ldconfig. 2023-03-13 09:20:28 +08:00
Kacper Piwiński
e78c4c4983 linux: fix ntp_gettime abi break (BZ# 30156)
Between versions v2.11 and v2.12 struct ntptimeval got new fields.
That wasn't a problem because new function ntp_gettimex was created
(and made default) to support new struct.  Old ntp_gettime was not
using new fields so it was safe to call with old struct
definition.  Then commits 5613afe9e3 and b6ad64b907 (added for
64 bit time_t support), ntp_gettime start setting new fields.

Sets fields manually to maintain compatibility with v2.11 struct
definition.

Resolves #30156

Reviewed-by: Adhemerval Zanella  <adhemerval.zanella@linaro.org>
2023-03-10 15:07:55 -03:00
abushwang
0b7bf0e0a4 rt: fix shm_open not set ENAMETOOLONG when name exceeds {_POSIX_PATH_MAX}
according to man-pages-posix-2017, shm_open() function may fail if the length
of the name argument exceeds {_POSIX_PATH_MAX} and set ENAMETOOLONG

Signed-off-by: abushwang <abushwangs@gmail.com>
Reviewed-by: Adhemerval Zanella  <adhemerval.zanella@linaro.org>
2023-03-08 10:11:54 -03:00
caiyinyu
4c721f24fc x86: Fix bug about glibc.cpu.hwcaps.
Recorded in [BZ #30183]:

1. export GLIBC_TUNABLES=glibc.cpu.hwcaps=-AVX512
2. Add  _dl_printf("p -- %s\n", p); just before switch(nl) in
   sysdeps/x86/cpu-tunables.c
3. compiled and run ./testrun.sh /usr/bin/ls
you will get:

p -- -AVX512
p -- LC_ADDRESS=en_US.UTF-8
p -- LC_NUMERIC=C
...

The function, TUNABLE_CALLBACK (set_hwcaps)
(tunable_val_t *valp), checks far more than it should and it
should stop at end of "-AVX512".
2023-03-07 21:42:25 +08:00
Adam Yi
436a604b7d posix: Fix system blocks SIGCHLD erroneously [BZ #30163]
Fix bug that SIGCHLD is erroneously blocked forever in the following
scenario:

1. Thread A calls system but hasn't returned yet
2. Thread B calls another system but returns

SIGCHLD would be blocked forever in thread B after its system() returns,
even after the system() in thread A returns.

Although POSIX does not require, glibc system implementation aims to be
thread and cancellation safe. This bug was introduced in
5fb7fc9635 when we moved reverting signal
mask to happen when the last concurrently running system returns,
despite that signal mask is per thread. This commit reverts this logic
and adds a test.

Signed-off-by: Adam Yi <ayi@janestreet.com>
Reviewed-by: Adhemerval Zanella  <adhemerval.zanella@linaro.org>
2023-03-07 09:54:50 -03:00