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Message-ID: <bb3c4bdb-158c-0aa4-9b4f-401da2a1ed61@redhat.com>
Date: Mon, 16 May 2022 17:12:43 -0400
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Subject: Re: [PATCH v2 01/15] linux: Add pidfd_open
To: Adhemerval Zanella <adhemerval.zanella@linaro.org>,
 libc-alpha@sourceware.org
References: <20220207174431.360355-1-adhemerval.zanella@linaro.org>
 <20220207174431.360355-2-adhemerval.zanella@linaro.org>
From: Carlos O'Donell <carlos@redhat.com>
Organization: Red Hat
In-Reply-To: <20220207174431.360355-2-adhemerval.zanella@linaro.org>
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On 2/7/22 12:44, Adhemerval Zanella via Libc-alpha wrote:
> This was added on Linux 5.3 (32fcb426ec001cb6d5a4a195091a8486ea77e2df)
> as a way to retrieve a pid file descriptors for process that has not
> been created CLONE_PIDFD (by usual fork/clone).

The only ABI parts are: the function name, pid_t (already exposed),
unsigned int flags, the constant used in the flags. I checked each of
those matches the kernel.

OK with updated NEWS entry.

Reviewed-by: Carlos O'Donell <carlos@redhat.com>
Tested-by: Carlos O'Donell <carlos@redhat.com>


> ---
> v2: Add kernel version check on compare_macro_consts.
> ---
>  NEWS                                          |  3 +-
>  sysdeps/unix/sysv/linux/Makefile              | 11 ++++-
>  sysdeps/unix/sysv/linux/Versions              |  3 ++
>  sysdeps/unix/sysv/linux/aarch64/libc.abilist  |  1 +
>  sysdeps/unix/sysv/linux/alpha/libc.abilist    |  1 +
>  sysdeps/unix/sysv/linux/arc/libc.abilist      |  1 +
>  sysdeps/unix/sysv/linux/arm/be/libc.abilist   |  1 +
>  sysdeps/unix/sysv/linux/arm/le/libc.abilist   |  1 +
>  sysdeps/unix/sysv/linux/csky/libc.abilist     |  1 +
>  sysdeps/unix/sysv/linux/hppa/libc.abilist     |  1 +
>  sysdeps/unix/sysv/linux/i386/libc.abilist     |  1 +
>  sysdeps/unix/sysv/linux/ia64/libc.abilist     |  1 +
>  .../sysv/linux/m68k/coldfire/libc.abilist     |  1 +
>  .../unix/sysv/linux/m68k/m680x0/libc.abilist  |  1 +
>  .../sysv/linux/microblaze/be/libc.abilist     |  1 +
>  .../sysv/linux/microblaze/le/libc.abilist     |  1 +
>  .../sysv/linux/mips/mips32/fpu/libc.abilist   |  1 +
>  .../sysv/linux/mips/mips32/nofpu/libc.abilist |  1 +
>  .../sysv/linux/mips/mips64/n32/libc.abilist   |  1 +
>  .../sysv/linux/mips/mips64/n64/libc.abilist   |  1 +
>  sysdeps/unix/sysv/linux/nios2/libc.abilist    |  1 +
>  sysdeps/unix/sysv/linux/or1k/libc.abilist     |  1 +
>  .../linux/powerpc/powerpc32/fpu/libc.abilist  |  1 +
>  .../powerpc/powerpc32/nofpu/libc.abilist      |  1 +
>  .../linux/powerpc/powerpc64/be/libc.abilist   |  1 +
>  .../linux/powerpc/powerpc64/le/libc.abilist   |  1 +
>  .../unix/sysv/linux/riscv/rv32/libc.abilist   |  1 +
>  .../unix/sysv/linux/riscv/rv64/libc.abilist   |  1 +
>  .../unix/sysv/linux/s390/s390-32/libc.abilist |  1 +
>  .../unix/sysv/linux/s390/s390-64/libc.abilist |  1 +
>  sysdeps/unix/sysv/linux/sh/be/libc.abilist    |  1 +
>  sysdeps/unix/sysv/linux/sh/le/libc.abilist    |  1 +
>  .../sysv/linux/sparc/sparc32/libc.abilist     |  1 +
>  .../sysv/linux/sparc/sparc64/libc.abilist     |  1 +
>  sysdeps/unix/sysv/linux/sys/pidfd.h           | 33 +++++++++++++
>  sysdeps/unix/sysv/linux/syscalls.list         |  1 +
>  sysdeps/unix/sysv/linux/tst-pidfd-consts.py   | 49 +++++++++++++++++++
>  .../unix/sysv/linux/x86_64/64/libc.abilist    |  1 +
>  .../unix/sysv/linux/x86_64/x32/libc.abilist   |  1 +
>  39 files changed, 131 insertions(+), 2 deletions(-)
>  create mode 100644 sysdeps/unix/sysv/linux/sys/pidfd.h
>  create mode 100644 sysdeps/unix/sysv/linux/tst-pidfd-consts.py
> 
> diff --git a/NEWS b/NEWS
> index 7b8febcb72..daae9a9646 100644
> --- a/NEWS
> +++ b/NEWS
> @@ -9,7 +9,8 @@ Version 2.36
>  
>  Major new features:
>  
> -  [Add new features here]
> +* On Linux, the pidfd_open function has been added.  The pidfd functionality
> +  to solve the issue of PID reuse in Unix systems.

Suggest:

"The pidfd functionality provides access to a process while avoiding the issue of
 PID reuse on tranditional Unix systems."


>  
>  Deprecated and removed features, and other changes affecting compatibility:
>  
> diff --git a/sysdeps/unix/sysv/linux/Makefile b/sysdeps/unix/sysv/linux/Makefile
> index 7122f55975..1c08f0918f 100644
> --- a/sysdeps/unix/sysv/linux/Makefile
> +++ b/sysdeps/unix/sysv/linux/Makefile
> @@ -113,7 +113,8 @@ sysdep_headers += sys/mount.h sys/acct.h \
>  		  bits/types/struct_shmid64_ds.h \
>  		  bits/types/struct_shmid64_ds_helper.h \
>  		  bits/pthread_stack_min.h bits/pthread_stack_min-dynamic.h \
> -		  sys/rseq.h bits/rseq.h
> +		  sys/rseq.h bits/rseq.h \
> +		  sys/pidfd.h

OK. New public header.

>  
>  tests += tst-clone tst-clone2 tst-clone3 tst-fanotify tst-personality \
>  	 tst-quota tst-sync_file_range tst-sysconf-iov_max tst-ttyname \
> @@ -236,6 +237,14 @@ $(objpfx)tst-mman-consts.out: ../sysdeps/unix/sysv/linux/tst-mman-consts.py
>  	  < /dev/null > $@ 2>&1; $(evaluate-test)
>  $(objpfx)tst-mman-consts.out: $(sysdeps-linux-python-deps)
>  
> +tests-special += $(objpfx)tst-pidfd-consts.out
> +$(objpfx)tst-pidfd-consts.out: ../sysdeps/unix/sysv/linux/tst-pidfd-consts.py
> +	$(sysdeps-linux-python) \
> +	  ../sysdeps/unix/sysv/linux/tst-pidfd-consts.py \
> +	    $(sysdeps-linux-python-cc) \
> +	  < /dev/null > $@ 2>&1; $(evaluate-test)
> +$(objpfx)tst-pidfd-consts.out: $(sysdeps-linux-python-deps)

OK. Test is always run because it's python.

> +
>  tst-rseq-disable-ENV = GLIBC_TUNABLES=glibc.pthread.rseq=0
>  
>  endif # $(subdir) == misc
> diff --git a/sysdeps/unix/sysv/linux/Versions b/sysdeps/unix/sysv/linux/Versions
> index ded087f30e..4516a8f8f4 100644
> --- a/sysdeps/unix/sysv/linux/Versions
> +++ b/sysdeps/unix/sysv/linux/Versions
> @@ -299,6 +299,9 @@ libc {
>  %endif
>      epoll_pwait2;
>    }
> +  GLIBC_2.36 {
> +    pidfd_open;
> +  }

OK.

>    GLIBC_PRIVATE {
>      # functions used in other libraries
>      __syscall_rt_sigqueueinfo;
> diff --git a/sysdeps/unix/sysv/linux/aarch64/libc.abilist b/sysdeps/unix/sysv/linux/aarch64/libc.abilist
> index 1b63d9e447..771d580bd9 100644
> --- a/sysdeps/unix/sysv/linux/aarch64/libc.abilist
> +++ b/sysdeps/unix/sysv/linux/aarch64/libc.abilist
> @@ -2616,3 +2616,4 @@ GLIBC_2.35 __memcmpeq F
>  GLIBC_2.35 _dl_find_object F
>  GLIBC_2.35 epoll_pwait2 F
>  GLIBC_2.35 posix_spawn_file_actions_addtcsetpgrp_np F
> +GLIBC_2.36 pidfd_open F
> diff --git a/sysdeps/unix/sysv/linux/alpha/libc.abilist b/sysdeps/unix/sysv/linux/alpha/libc.abilist
> index e7e4cf7d2a..a9c4e5b1d2 100644
> --- a/sysdeps/unix/sysv/linux/alpha/libc.abilist
> +++ b/sysdeps/unix/sysv/linux/alpha/libc.abilist
> @@ -2713,6 +2713,7 @@ GLIBC_2.35 __memcmpeq F
>  GLIBC_2.35 _dl_find_object F
>  GLIBC_2.35 epoll_pwait2 F
>  GLIBC_2.35 posix_spawn_file_actions_addtcsetpgrp_np F
> +GLIBC_2.36 pidfd_open F
>  GLIBC_2.4 _IO_fprintf F
>  GLIBC_2.4 _IO_printf F
>  GLIBC_2.4 _IO_sprintf F
> diff --git a/sysdeps/unix/sysv/linux/arc/libc.abilist b/sysdeps/unix/sysv/linux/arc/libc.abilist
> index bc3d228e31..e147803167 100644
> --- a/sysdeps/unix/sysv/linux/arc/libc.abilist
> +++ b/sysdeps/unix/sysv/linux/arc/libc.abilist
> @@ -2377,3 +2377,4 @@ GLIBC_2.35 __memcmpeq F
>  GLIBC_2.35 _dl_find_object F
>  GLIBC_2.35 epoll_pwait2 F
>  GLIBC_2.35 posix_spawn_file_actions_addtcsetpgrp_np F
> +GLIBC_2.36 pidfd_open F
> diff --git a/sysdeps/unix/sysv/linux/arm/be/libc.abilist b/sysdeps/unix/sysv/linux/arm/be/libc.abilist
> index db7039c4ab..4d1695e4a4 100644
> --- a/sysdeps/unix/sysv/linux/arm/be/libc.abilist
> +++ b/sysdeps/unix/sysv/linux/arm/be/libc.abilist
> @@ -496,6 +496,7 @@ GLIBC_2.35 __memcmpeq F
>  GLIBC_2.35 _dl_find_object F
>  GLIBC_2.35 epoll_pwait2 F
>  GLIBC_2.35 posix_spawn_file_actions_addtcsetpgrp_np F
> +GLIBC_2.36 pidfd_open F
>  GLIBC_2.4 _Exit F
>  GLIBC_2.4 _IO_2_1_stderr_ D 0xa0
>  GLIBC_2.4 _IO_2_1_stdin_ D 0xa0
> diff --git a/sysdeps/unix/sysv/linux/arm/le/libc.abilist b/sysdeps/unix/sysv/linux/arm/le/libc.abilist
> index d2add4fb49..600e8a977a 100644
> --- a/sysdeps/unix/sysv/linux/arm/le/libc.abilist
> +++ b/sysdeps/unix/sysv/linux/arm/le/libc.abilist
> @@ -493,6 +493,7 @@ GLIBC_2.35 __memcmpeq F
>  GLIBC_2.35 _dl_find_object F
>  GLIBC_2.35 epoll_pwait2 F
>  GLIBC_2.35 posix_spawn_file_actions_addtcsetpgrp_np F
> +GLIBC_2.36 pidfd_open F
>  GLIBC_2.4 _Exit F
>  GLIBC_2.4 _IO_2_1_stderr_ D 0xa0
>  GLIBC_2.4 _IO_2_1_stdin_ D 0xa0
> diff --git a/sysdeps/unix/sysv/linux/csky/libc.abilist b/sysdeps/unix/sysv/linux/csky/libc.abilist
> index 355d72a30c..be1671372a 100644
> --- a/sysdeps/unix/sysv/linux/csky/libc.abilist
> +++ b/sysdeps/unix/sysv/linux/csky/libc.abilist
> @@ -2652,3 +2652,4 @@ GLIBC_2.35 __memcmpeq F
>  GLIBC_2.35 _dl_find_object F
>  GLIBC_2.35 epoll_pwait2 F
>  GLIBC_2.35 posix_spawn_file_actions_addtcsetpgrp_np F
> +GLIBC_2.36 pidfd_open F
> diff --git a/sysdeps/unix/sysv/linux/hppa/libc.abilist b/sysdeps/unix/sysv/linux/hppa/libc.abilist
> index 3df39bb28c..7d09b909cd 100644
> --- a/sysdeps/unix/sysv/linux/hppa/libc.abilist
> +++ b/sysdeps/unix/sysv/linux/hppa/libc.abilist
> @@ -2601,6 +2601,7 @@ GLIBC_2.35 __memcmpeq F
>  GLIBC_2.35 _dl_find_object F
>  GLIBC_2.35 epoll_pwait2 F
>  GLIBC_2.35 posix_spawn_file_actions_addtcsetpgrp_np F
> +GLIBC_2.36 pidfd_open F
>  GLIBC_2.4 __confstr_chk F
>  GLIBC_2.4 __fgets_chk F
>  GLIBC_2.4 __fgets_unlocked_chk F
> diff --git a/sysdeps/unix/sysv/linux/i386/libc.abilist b/sysdeps/unix/sysv/linux/i386/libc.abilist
> index c4da358f80..89da416c37 100644
> --- a/sysdeps/unix/sysv/linux/i386/libc.abilist
> +++ b/sysdeps/unix/sysv/linux/i386/libc.abilist
> @@ -2785,6 +2785,7 @@ GLIBC_2.35 __memcmpeq F
>  GLIBC_2.35 _dl_find_object F
>  GLIBC_2.35 epoll_pwait2 F
>  GLIBC_2.35 posix_spawn_file_actions_addtcsetpgrp_np F
> +GLIBC_2.36 pidfd_open F
>  GLIBC_2.4 __confstr_chk F
>  GLIBC_2.4 __fgets_chk F
>  GLIBC_2.4 __fgets_unlocked_chk F
> diff --git a/sysdeps/unix/sysv/linux/ia64/libc.abilist b/sysdeps/unix/sysv/linux/ia64/libc.abilist
> index 241bac70ea..4e4faed24b 100644
> --- a/sysdeps/unix/sysv/linux/ia64/libc.abilist
> +++ b/sysdeps/unix/sysv/linux/ia64/libc.abilist
> @@ -2551,6 +2551,7 @@ GLIBC_2.35 __memcmpeq F
>  GLIBC_2.35 _dl_find_object F
>  GLIBC_2.35 epoll_pwait2 F
>  GLIBC_2.35 posix_spawn_file_actions_addtcsetpgrp_np F
> +GLIBC_2.36 pidfd_open F
>  GLIBC_2.4 __confstr_chk F
>  GLIBC_2.4 __fgets_chk F
>  GLIBC_2.4 __fgets_unlocked_chk F
> diff --git a/sysdeps/unix/sysv/linux/m68k/coldfire/libc.abilist b/sysdeps/unix/sysv/linux/m68k/coldfire/libc.abilist
> index 78bf372b72..83f61f95fd 100644
> --- a/sysdeps/unix/sysv/linux/m68k/coldfire/libc.abilist
> +++ b/sysdeps/unix/sysv/linux/m68k/coldfire/libc.abilist
> @@ -497,6 +497,7 @@ GLIBC_2.35 __memcmpeq F
>  GLIBC_2.35 _dl_find_object F
>  GLIBC_2.35 epoll_pwait2 F
>  GLIBC_2.35 posix_spawn_file_actions_addtcsetpgrp_np F
> +GLIBC_2.36 pidfd_open F
>  GLIBC_2.4 _Exit F
>  GLIBC_2.4 _IO_2_1_stderr_ D 0x98
>  GLIBC_2.4 _IO_2_1_stdin_ D 0x98
> diff --git a/sysdeps/unix/sysv/linux/m68k/m680x0/libc.abilist b/sysdeps/unix/sysv/linux/m68k/m680x0/libc.abilist
> index 00df5c901f..9f815f8b99 100644
> --- a/sysdeps/unix/sysv/linux/m68k/m680x0/libc.abilist
> +++ b/sysdeps/unix/sysv/linux/m68k/m680x0/libc.abilist
> @@ -2728,6 +2728,7 @@ GLIBC_2.35 __memcmpeq F
>  GLIBC_2.35 _dl_find_object F
>  GLIBC_2.35 epoll_pwait2 F
>  GLIBC_2.35 posix_spawn_file_actions_addtcsetpgrp_np F
> +GLIBC_2.36 pidfd_open F
>  GLIBC_2.4 __confstr_chk F
>  GLIBC_2.4 __fgets_chk F
>  GLIBC_2.4 __fgets_unlocked_chk F
> diff --git a/sysdeps/unix/sysv/linux/microblaze/be/libc.abilist b/sysdeps/unix/sysv/linux/microblaze/be/libc.abilist
> index e8118569c3..d758594032 100644
> --- a/sysdeps/unix/sysv/linux/microblaze/be/libc.abilist
> +++ b/sysdeps/unix/sysv/linux/microblaze/be/libc.abilist
> @@ -2701,3 +2701,4 @@ GLIBC_2.35 __memcmpeq F
>  GLIBC_2.35 _dl_find_object F
>  GLIBC_2.35 epoll_pwait2 F
>  GLIBC_2.35 posix_spawn_file_actions_addtcsetpgrp_np F
> +GLIBC_2.36 pidfd_open F
> diff --git a/sysdeps/unix/sysv/linux/microblaze/le/libc.abilist b/sysdeps/unix/sysv/linux/microblaze/le/libc.abilist
> index c0d2373e64..6d9d415936 100644
> --- a/sysdeps/unix/sysv/linux/microblaze/le/libc.abilist
> +++ b/sysdeps/unix/sysv/linux/microblaze/le/libc.abilist
> @@ -2698,3 +2698,4 @@ GLIBC_2.35 __memcmpeq F
>  GLIBC_2.35 _dl_find_object F
>  GLIBC_2.35 epoll_pwait2 F
>  GLIBC_2.35 posix_spawn_file_actions_addtcsetpgrp_np F
> +GLIBC_2.36 pidfd_open F
> diff --git a/sysdeps/unix/sysv/linux/mips/mips32/fpu/libc.abilist b/sysdeps/unix/sysv/linux/mips/mips32/fpu/libc.abilist
> index 2d0fd04f54..b31f7b88cd 100644
> --- a/sysdeps/unix/sysv/linux/mips/mips32/fpu/libc.abilist
> +++ b/sysdeps/unix/sysv/linux/mips/mips32/fpu/libc.abilist
> @@ -2693,6 +2693,7 @@ GLIBC_2.35 __memcmpeq F
>  GLIBC_2.35 _dl_find_object F
>  GLIBC_2.35 epoll_pwait2 F
>  GLIBC_2.35 posix_spawn_file_actions_addtcsetpgrp_np F
> +GLIBC_2.36 pidfd_open F
>  GLIBC_2.4 __confstr_chk F
>  GLIBC_2.4 __fgets_chk F
>  GLIBC_2.4 __fgets_unlocked_chk F
> diff --git a/sysdeps/unix/sysv/linux/mips/mips32/nofpu/libc.abilist b/sysdeps/unix/sysv/linux/mips/mips32/nofpu/libc.abilist
> index e39ccfb312..98ebcbdcbc 100644
> --- a/sysdeps/unix/sysv/linux/mips/mips32/nofpu/libc.abilist
> +++ b/sysdeps/unix/sysv/linux/mips/mips32/nofpu/libc.abilist
> @@ -2691,6 +2691,7 @@ GLIBC_2.35 __memcmpeq F
>  GLIBC_2.35 _dl_find_object F
>  GLIBC_2.35 epoll_pwait2 F
>  GLIBC_2.35 posix_spawn_file_actions_addtcsetpgrp_np F
> +GLIBC_2.36 pidfd_open F
>  GLIBC_2.4 __confstr_chk F
>  GLIBC_2.4 __fgets_chk F
>  GLIBC_2.4 __fgets_unlocked_chk F
> diff --git a/sysdeps/unix/sysv/linux/mips/mips64/n32/libc.abilist b/sysdeps/unix/sysv/linux/mips/mips64/n32/libc.abilist
> index 1e900f86e4..e6bae7d52d 100644
> --- a/sysdeps/unix/sysv/linux/mips/mips64/n32/libc.abilist
> +++ b/sysdeps/unix/sysv/linux/mips/mips64/n32/libc.abilist
> @@ -2699,6 +2699,7 @@ GLIBC_2.35 __memcmpeq F
>  GLIBC_2.35 _dl_find_object F
>  GLIBC_2.35 epoll_pwait2 F
>  GLIBC_2.35 posix_spawn_file_actions_addtcsetpgrp_np F
> +GLIBC_2.36 pidfd_open F
>  GLIBC_2.4 __confstr_chk F
>  GLIBC_2.4 __fgets_chk F
>  GLIBC_2.4 __fgets_unlocked_chk F
> diff --git a/sysdeps/unix/sysv/linux/mips/mips64/n64/libc.abilist b/sysdeps/unix/sysv/linux/mips/mips64/n64/libc.abilist
> index 9145ba7931..19f575d22d 100644
> --- a/sysdeps/unix/sysv/linux/mips/mips64/n64/libc.abilist
> +++ b/sysdeps/unix/sysv/linux/mips/mips64/n64/libc.abilist
> @@ -2602,6 +2602,7 @@ GLIBC_2.35 __memcmpeq F
>  GLIBC_2.35 _dl_find_object F
>  GLIBC_2.35 epoll_pwait2 F
>  GLIBC_2.35 posix_spawn_file_actions_addtcsetpgrp_np F
> +GLIBC_2.36 pidfd_open F
>  GLIBC_2.4 __confstr_chk F
>  GLIBC_2.4 __fgets_chk F
>  GLIBC_2.4 __fgets_unlocked_chk F
> diff --git a/sysdeps/unix/sysv/linux/nios2/libc.abilist b/sysdeps/unix/sysv/linux/nios2/libc.abilist
> index e95d60d926..04779199c2 100644
> --- a/sysdeps/unix/sysv/linux/nios2/libc.abilist
> +++ b/sysdeps/unix/sysv/linux/nios2/libc.abilist
> @@ -2740,3 +2740,4 @@ GLIBC_2.35 __memcmpeq F
>  GLIBC_2.35 _dl_find_object F
>  GLIBC_2.35 epoll_pwait2 F
>  GLIBC_2.35 posix_spawn_file_actions_addtcsetpgrp_np F
> +GLIBC_2.36 pidfd_open F
> diff --git a/sysdeps/unix/sysv/linux/or1k/libc.abilist b/sysdeps/unix/sysv/linux/or1k/libc.abilist
> index ca934e374b..df6ecdec8b 100644
> --- a/sysdeps/unix/sysv/linux/or1k/libc.abilist
> +++ b/sysdeps/unix/sysv/linux/or1k/libc.abilist
> @@ -2123,3 +2123,4 @@ GLIBC_2.35 wprintf F
>  GLIBC_2.35 write F
>  GLIBC_2.35 writev F
>  GLIBC_2.35 wscanf F
> +GLIBC_2.36 pidfd_open F
> diff --git a/sysdeps/unix/sysv/linux/powerpc/powerpc32/fpu/libc.abilist b/sysdeps/unix/sysv/linux/powerpc/powerpc32/fpu/libc.abilist
> index 3820b9f235..b618808e13 100644
> --- a/sysdeps/unix/sysv/linux/powerpc/powerpc32/fpu/libc.abilist
> +++ b/sysdeps/unix/sysv/linux/powerpc/powerpc32/fpu/libc.abilist
> @@ -2755,6 +2755,7 @@ GLIBC_2.35 __memcmpeq F
>  GLIBC_2.35 _dl_find_object F
>  GLIBC_2.35 epoll_pwait2 F
>  GLIBC_2.35 posix_spawn_file_actions_addtcsetpgrp_np F
> +GLIBC_2.36 pidfd_open F
>  GLIBC_2.4 _IO_fprintf F
>  GLIBC_2.4 _IO_printf F
>  GLIBC_2.4 _IO_sprintf F
> diff --git a/sysdeps/unix/sysv/linux/powerpc/powerpc32/nofpu/libc.abilist b/sysdeps/unix/sysv/linux/powerpc/powerpc32/nofpu/libc.abilist
> index 464dc27fcd..19eb5c4576 100644
> --- a/sysdeps/unix/sysv/linux/powerpc/powerpc32/nofpu/libc.abilist
> +++ b/sysdeps/unix/sysv/linux/powerpc/powerpc32/nofpu/libc.abilist
> @@ -2788,6 +2788,7 @@ GLIBC_2.35 __memcmpeq F
>  GLIBC_2.35 _dl_find_object F
>  GLIBC_2.35 epoll_pwait2 F
>  GLIBC_2.35 posix_spawn_file_actions_addtcsetpgrp_np F
> +GLIBC_2.36 pidfd_open F
>  GLIBC_2.4 _IO_fprintf F
>  GLIBC_2.4 _IO_printf F
>  GLIBC_2.4 _IO_sprintf F
> diff --git a/sysdeps/unix/sysv/linux/powerpc/powerpc64/be/libc.abilist b/sysdeps/unix/sysv/linux/powerpc/powerpc64/be/libc.abilist
> index 2f7e58747f..a54d3a16a2 100644
> --- a/sysdeps/unix/sysv/linux/powerpc/powerpc64/be/libc.abilist
> +++ b/sysdeps/unix/sysv/linux/powerpc/powerpc64/be/libc.abilist
> @@ -2510,6 +2510,7 @@ GLIBC_2.35 __memcmpeq F
>  GLIBC_2.35 _dl_find_object F
>  GLIBC_2.35 epoll_pwait2 F
>  GLIBC_2.35 posix_spawn_file_actions_addtcsetpgrp_np F
> +GLIBC_2.36 pidfd_open F
>  GLIBC_2.4 _IO_fprintf F
>  GLIBC_2.4 _IO_printf F
>  GLIBC_2.4 _IO_sprintf F
> diff --git a/sysdeps/unix/sysv/linux/powerpc/powerpc64/le/libc.abilist b/sysdeps/unix/sysv/linux/powerpc/powerpc64/le/libc.abilist
> index 4f3043d913..e829f4fb42 100644
> --- a/sysdeps/unix/sysv/linux/powerpc/powerpc64/le/libc.abilist
> +++ b/sysdeps/unix/sysv/linux/powerpc/powerpc64/le/libc.abilist
> @@ -2812,3 +2812,4 @@ GLIBC_2.35 __memcmpeq F
>  GLIBC_2.35 _dl_find_object F
>  GLIBC_2.35 epoll_pwait2 F
>  GLIBC_2.35 posix_spawn_file_actions_addtcsetpgrp_np F
> +GLIBC_2.36 pidfd_open F
> diff --git a/sysdeps/unix/sysv/linux/riscv/rv32/libc.abilist b/sysdeps/unix/sysv/linux/riscv/rv32/libc.abilist
> index 84b6ac815a..2f0c9a81d2 100644
> --- a/sysdeps/unix/sysv/linux/riscv/rv32/libc.abilist
> +++ b/sysdeps/unix/sysv/linux/riscv/rv32/libc.abilist
> @@ -2379,3 +2379,4 @@ GLIBC_2.35 __memcmpeq F
>  GLIBC_2.35 _dl_find_object F
>  GLIBC_2.35 epoll_pwait2 F
>  GLIBC_2.35 posix_spawn_file_actions_addtcsetpgrp_np F
> +GLIBC_2.36 pidfd_open F
> diff --git a/sysdeps/unix/sysv/linux/riscv/rv64/libc.abilist b/sysdeps/unix/sysv/linux/riscv/rv64/libc.abilist
> index 4d5c19c56a..e4b61e880a 100644
> --- a/sysdeps/unix/sysv/linux/riscv/rv64/libc.abilist
> +++ b/sysdeps/unix/sysv/linux/riscv/rv64/libc.abilist
> @@ -2579,3 +2579,4 @@ GLIBC_2.35 __memcmpeq F
>  GLIBC_2.35 _dl_find_object F
>  GLIBC_2.35 epoll_pwait2 F
>  GLIBC_2.35 posix_spawn_file_actions_addtcsetpgrp_np F
> +GLIBC_2.36 pidfd_open F
> diff --git a/sysdeps/unix/sysv/linux/s390/s390-32/libc.abilist b/sysdeps/unix/sysv/linux/s390/s390-32/libc.abilist
> index 7c5ee8d569..b7ee961dd6 100644
> --- a/sysdeps/unix/sysv/linux/s390/s390-32/libc.abilist
> +++ b/sysdeps/unix/sysv/linux/s390/s390-32/libc.abilist
> @@ -2753,6 +2753,7 @@ GLIBC_2.35 __memcmpeq F
>  GLIBC_2.35 _dl_find_object F
>  GLIBC_2.35 epoll_pwait2 F
>  GLIBC_2.35 posix_spawn_file_actions_addtcsetpgrp_np F
> +GLIBC_2.36 pidfd_open F
>  GLIBC_2.4 _IO_fprintf F
>  GLIBC_2.4 _IO_printf F
>  GLIBC_2.4 _IO_sprintf F
> diff --git a/sysdeps/unix/sysv/linux/s390/s390-64/libc.abilist b/sysdeps/unix/sysv/linux/s390/s390-64/libc.abilist
> index 50de0b46cf..53d49565b3 100644
> --- a/sysdeps/unix/sysv/linux/s390/s390-64/libc.abilist
> +++ b/sysdeps/unix/sysv/linux/s390/s390-64/libc.abilist
> @@ -2547,6 +2547,7 @@ GLIBC_2.35 __memcmpeq F
>  GLIBC_2.35 _dl_find_object F
>  GLIBC_2.35 epoll_pwait2 F
>  GLIBC_2.35 posix_spawn_file_actions_addtcsetpgrp_np F
> +GLIBC_2.36 pidfd_open F
>  GLIBC_2.4 _IO_fprintf F
>  GLIBC_2.4 _IO_printf F
>  GLIBC_2.4 _IO_sprintf F
> diff --git a/sysdeps/unix/sysv/linux/sh/be/libc.abilist b/sysdeps/unix/sysv/linux/sh/be/libc.abilist
> index 66fba013ca..2179df05fa 100644
> --- a/sysdeps/unix/sysv/linux/sh/be/libc.abilist
> +++ b/sysdeps/unix/sysv/linux/sh/be/libc.abilist
> @@ -2608,6 +2608,7 @@ GLIBC_2.35 __memcmpeq F
>  GLIBC_2.35 _dl_find_object F
>  GLIBC_2.35 epoll_pwait2 F
>  GLIBC_2.35 posix_spawn_file_actions_addtcsetpgrp_np F
> +GLIBC_2.36 pidfd_open F
>  GLIBC_2.4 __confstr_chk F
>  GLIBC_2.4 __fgets_chk F
>  GLIBC_2.4 __fgets_unlocked_chk F
> diff --git a/sysdeps/unix/sysv/linux/sh/le/libc.abilist b/sysdeps/unix/sysv/linux/sh/le/libc.abilist
> index 38703f8aa0..bbf00df5eb 100644
> --- a/sysdeps/unix/sysv/linux/sh/le/libc.abilist
> +++ b/sysdeps/unix/sysv/linux/sh/le/libc.abilist
> @@ -2605,6 +2605,7 @@ GLIBC_2.35 __memcmpeq F
>  GLIBC_2.35 _dl_find_object F
>  GLIBC_2.35 epoll_pwait2 F
>  GLIBC_2.35 posix_spawn_file_actions_addtcsetpgrp_np F
> +GLIBC_2.36 pidfd_open F
>  GLIBC_2.4 __confstr_chk F
>  GLIBC_2.4 __fgets_chk F
>  GLIBC_2.4 __fgets_unlocked_chk F
> diff --git a/sysdeps/unix/sysv/linux/sparc/sparc32/libc.abilist b/sysdeps/unix/sysv/linux/sparc/sparc32/libc.abilist
> index 6df55eb765..e452cf8c88 100644
> --- a/sysdeps/unix/sysv/linux/sparc/sparc32/libc.abilist
> +++ b/sysdeps/unix/sysv/linux/sparc/sparc32/libc.abilist
> @@ -2748,6 +2748,7 @@ GLIBC_2.35 __memcmpeq F
>  GLIBC_2.35 _dl_find_object F
>  GLIBC_2.35 epoll_pwait2 F
>  GLIBC_2.35 posix_spawn_file_actions_addtcsetpgrp_np F
> +GLIBC_2.36 pidfd_open F
>  GLIBC_2.4 _IO_fprintf F
>  GLIBC_2.4 _IO_printf F
>  GLIBC_2.4 _IO_sprintf F
> diff --git a/sysdeps/unix/sysv/linux/sparc/sparc64/libc.abilist b/sysdeps/unix/sysv/linux/sparc/sparc64/libc.abilist
> index b90569d881..0c401996f8 100644
> --- a/sysdeps/unix/sysv/linux/sparc/sparc64/libc.abilist
> +++ b/sysdeps/unix/sysv/linux/sparc/sparc64/libc.abilist
> @@ -2574,6 +2574,7 @@ GLIBC_2.35 __memcmpeq F
>  GLIBC_2.35 _dl_find_object F
>  GLIBC_2.35 epoll_pwait2 F
>  GLIBC_2.35 posix_spawn_file_actions_addtcsetpgrp_np F
> +GLIBC_2.36 pidfd_open F
>  GLIBC_2.4 __confstr_chk F
>  GLIBC_2.4 __fgets_chk F
>  GLIBC_2.4 __fgets_unlocked_chk F
> diff --git a/sysdeps/unix/sysv/linux/sys/pidfd.h b/sysdeps/unix/sysv/linux/sys/pidfd.h
> new file mode 100644
> index 0000000000..dab2710a91
> --- /dev/null
> +++ b/sysdeps/unix/sysv/linux/sys/pidfd.h
> @@ -0,0 +1,33 @@
> +/* Wrapper for file descriptors that refers to a process functions.
> +   Copyright (C) 2022 Free Software Foundation, Inc.
> +   This file is part of the GNU C Library.
> +
> +   The GNU C Library is free software; you can redistribute it and/or
> +   modify it under the terms of the GNU Lesser General Public
> +   License as published by the Free Software Foundation; either
> +   version 2.1 of the License, or (at your option) any later version.
> +
> +   The GNU C Library is distributed in the hope that it will be useful,
> +   but WITHOUT ANY WARRANTY; without even the implied warranty of
> +   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
> +   Lesser General Public License for more details.
> +
> +   You should have received a copy of the GNU Lesser General Public
> +   License along with the GNU C Library; if not, see
> +   <https://www.gnu.org/licenses/>.  */
> +
> +#ifndef _PIDFD_H
> +
> +#include <fcntl.h>
> +#include <bits/types/siginfo_t.h>
> +
> +#define PIDFD_NONBLOCK O_NONBLOCK

OK. Confirmed with upstream kernel, PIDFD_NONBLOCK is defined as O_NONBLOCK.

> +
> +/* Returns a file descriptor that refers to the process PID.  The
> +   close-on-exec is set on the file descriptor.
> +
> +   The FLAGS argument is reserved for future use, it must be specified
> +   as 0.  */
> +extern int pidfd_open (__pid_t __pid, unsigned int __flags) __THROW;

OK.

> +
> +#endif /* _PIDFD_H  */
> diff --git a/sysdeps/unix/sysv/linux/syscalls.list b/sysdeps/unix/sysv/linux/syscalls.list
> index c93c0d8193..296dccbcb0 100644
> --- a/sysdeps/unix/sysv/linux/syscalls.list
> +++ b/sysdeps/unix/sysv/linux/syscalls.list
> @@ -39,6 +39,7 @@ munlock		-	munlock		i:aU	munlock
>  munlockall	-	munlockall	i:	munlockall
>  nfsservctl	EXTRA	nfsservctl	i:ipp	__compat_nfsservctl	nfsservctl@GLIBC_2.0:GLIBC_2.28
>  pipe2		-	pipe2		i:fi	__pipe2		pipe2
> +pidfd_open	EXTRA	pidfd_open	i:iU	pidfd_open

OK.

>  pivot_root	EXTRA	pivot_root	i:ss	pivot_root
>  query_module	EXTRA	query_module	i:sipip	__compat_query_module	query_module@GLIBC_2.0:GLIBC_2.23
>  quotactl	EXTRA	quotactl	i:isip	quotactl
> diff --git a/sysdeps/unix/sysv/linux/tst-pidfd-consts.py b/sysdeps/unix/sysv/linux/tst-pidfd-consts.py
> new file mode 100644
> index 0000000000..795621bbd9
> --- /dev/null
> +++ b/sysdeps/unix/sysv/linux/tst-pidfd-consts.py
> @@ -0,0 +1,49 @@
> +#!/usr/bin/python3
> +# Test that glibc's sys/pidfd.h constants match the kernel's.
> +# Copyright (C) 2022 Free Software Foundation, Inc.
> +# This file is part of the GNU C Library.
> +#
> +# The GNU C Library is free software; you can redistribute it and/or
> +# modify it under the terms of the GNU Lesser General Public
> +# License as published by the Free Software Foundation; either
> +# version 2.1 of the License, or (at your option) any later version.
> +#
> +# The GNU C Library is distributed in the hope that it will be useful,
> +# but WITHOUT ANY WARRANTY; without even the implied warranty of
> +# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
> +# Lesser General Public License for more details.
> +#
> +# You should have received a copy of the GNU Lesser General Public
> +# License along with the GNU C Library; if not, see
> +# <https://www.gnu.org/licenses/>.
> +
> +import argparse
> +import sys
> +
> +import glibcextract
> +import glibcsyscalls
> +
> +
> +def main():
> +    """The main entry point."""
> +    parser = argparse.ArgumentParser(
> +        description="Test that glibc's sys/pidfd.h constants "
> +        "match the kernel's.")
> +    parser.add_argument('--cc', metavar='CC',
> +                        help='C compiler (including options) to use')
> +    args = parser.parse_args()
> +
> +    linux_version_headers = glibcsyscalls.linux_kernel_version(args.cc)
> +    linux_version_glibc = (5, 16)
> +    sys.exit(glibcextract.compare_macro_consts(
> +                '#include <sys/pidfd.h>\n',
> +                '#include <asm/fcntl.h>\n'
> +                '#include <linux/pidfd.h>\n',
> +                args.cc,
> +                'PIDFD_.*',

OK.

> +                None,
> +                linux_version_glibc > linux_version_headers,
> +                linux_version_headers > linux_version_glibc))
> +
> +if __name__ == '__main__':
> +    main()

OK. Adds new test to make sure constants stay matching.

> diff --git a/sysdeps/unix/sysv/linux/x86_64/64/libc.abilist b/sysdeps/unix/sysv/linux/x86_64/64/libc.abilist
> index e88b0f101f..0148a68853 100644
> --- a/sysdeps/unix/sysv/linux/x86_64/64/libc.abilist
> +++ b/sysdeps/unix/sysv/linux/x86_64/64/libc.abilist
> @@ -2525,6 +2525,7 @@ GLIBC_2.35 __memcmpeq F
>  GLIBC_2.35 _dl_find_object F
>  GLIBC_2.35 epoll_pwait2 F
>  GLIBC_2.35 posix_spawn_file_actions_addtcsetpgrp_np F
> +GLIBC_2.36 pidfd_open F
>  GLIBC_2.4 __confstr_chk F
>  GLIBC_2.4 __fgets_chk F
>  GLIBC_2.4 __fgets_unlocked_chk F
> diff --git a/sysdeps/unix/sysv/linux/x86_64/x32/libc.abilist b/sysdeps/unix/sysv/linux/x86_64/x32/libc.abilist
> index e0755272eb..0efc2676c3 100644
> --- a/sysdeps/unix/sysv/linux/x86_64/x32/libc.abilist
> +++ b/sysdeps/unix/sysv/linux/x86_64/x32/libc.abilist
> @@ -2631,3 +2631,4 @@ GLIBC_2.35 __memcmpeq F
>  GLIBC_2.35 _dl_find_object F
>  GLIBC_2.35 epoll_pwait2 F
>  GLIBC_2.35 posix_spawn_file_actions_addtcsetpgrp_np F
> +GLIBC_2.36 pidfd_open F


-- 
Cheers,
Carlos.