[PATCH 4/4] linux: Add pidfd_getpid
Adhemerval Zanella
adhemerval.zanella@linaro.org
Tue Apr 18 21:35:05 GMT 2023
This interface allows to obtain the associated pid ID from the
process file descriptor. It is done by parsing the procps fdinfo
information.
Checked on x86_64-linux-gnu on Linux 4.15 (no CLONE_PID or waitid
support), Linux 5.15 (only clone support), and Linux 5.19 (full
support including clone3).
---
NEWS | 4 +
sysdeps/unix/sysv/linux/Makefile | 2 +
sysdeps/unix/sysv/linux/Versions | 1 +
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/loongarch/lp64/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 +
sysdeps/unix/sysv/linux/pidfd_getpid.c | 70 +++++++++++++
.../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 +
sysdeps/unix/sysv/linux/procutils.c | 99 +++++++++++++++++++
sysdeps/unix/sysv/linux/procutils.h | 37 +++++++
.../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 | 4 +
sysdeps/unix/sysv/linux/tst-pidfd.c | 7 ++
.../unix/sysv/linux/x86_64/64/libc.abilist | 1 +
.../unix/sysv/linux/x86_64/x32/libc.abilist | 1 +
42 files changed, 258 insertions(+)
create mode 100644 sysdeps/unix/sysv/linux/pidfd_getpid.c
create mode 100644 sysdeps/unix/sysv/linux/procutils.c
create mode 100644 sysdeps/unix/sysv/linux/procutils.h
diff --git a/NEWS b/NEWS
index 2ac69a8a2c..39b5f8beb0 100644
--- a/NEWS
+++ b/NEWS
@@ -33,6 +33,10 @@ Major new features:
return a process ID, it returns a file descriptor that can be used along
other pidfd functions.
+* On Linux, the pidfd_getpid has been added. It allows to retrieve the
+ process ID associated with process file descriptor created with
+ pid_spawn or pidfd_fork.
+
Deprecated and removed features, and other changes affecting compatibility:
* In the Linux kernel for the hppa/parisc architecture some of the
diff --git a/sysdeps/unix/sysv/linux/Makefile b/sysdeps/unix/sysv/linux/Makefile
index 7f0233449f..ab309b13a9 100644
--- a/sysdeps/unix/sysv/linux/Makefile
+++ b/sysdeps/unix/sysv/linux/Makefile
@@ -441,8 +441,10 @@ sysdep_routines += \
oldglob \
sched_getcpu \
pidfd_fork \
+ pidfd_getpid \
pidfd_spawn \
pidfd_spawnp \
+ procutils \
# sysdep_routines
tests += \
diff --git a/sysdeps/unix/sysv/linux/Versions b/sysdeps/unix/sysv/linux/Versions
index 7e4109e9c5..047bc0c92a 100644
--- a/sysdeps/unix/sysv/linux/Versions
+++ b/sysdeps/unix/sysv/linux/Versions
@@ -323,6 +323,7 @@ libc {
}
GLIBC_2.38 {
pidfd_fork;
+ pidfd_getpid;
pidfd_spawn;
pidfd_spawnp;
}
diff --git a/sysdeps/unix/sysv/linux/aarch64/libc.abilist b/sysdeps/unix/sysv/linux/aarch64/libc.abilist
index dbf7c44319..febfc78f29 100644
--- a/sysdeps/unix/sysv/linux/aarch64/libc.abilist
+++ b/sysdeps/unix/sysv/linux/aarch64/libc.abilist
@@ -2666,5 +2666,6 @@ GLIBC_2.38 __isoc23_wcstoull_l F
GLIBC_2.38 __isoc23_wcstoumax F
GLIBC_2.38 __isoc23_wscanf F
GLIBC_2.38 pidfd_fork F
+GLIBC_2.38 pidfd_getpid F
GLIBC_2.38 pidfd_spawn F
GLIBC_2.38 pidfd_spawnp F
diff --git a/sysdeps/unix/sysv/linux/alpha/libc.abilist b/sysdeps/unix/sysv/linux/alpha/libc.abilist
index a9d6ffce14..87f93beeb8 100644
--- a/sysdeps/unix/sysv/linux/alpha/libc.abilist
+++ b/sysdeps/unix/sysv/linux/alpha/libc.abilist
@@ -2775,6 +2775,7 @@ GLIBC_2.38 __nldbl___isoc23_vswscanf F
GLIBC_2.38 __nldbl___isoc23_vwscanf F
GLIBC_2.38 __nldbl___isoc23_wscanf F
GLIBC_2.38 pidfd_fork F
+GLIBC_2.38 pidfd_getpid F
GLIBC_2.38 pidfd_spawn F
GLIBC_2.38 pidfd_spawnp F
GLIBC_2.4 _IO_fprintf F
diff --git a/sysdeps/unix/sysv/linux/arc/libc.abilist b/sysdeps/unix/sysv/linux/arc/libc.abilist
index c08d548556..dd33567a75 100644
--- a/sysdeps/unix/sysv/linux/arc/libc.abilist
+++ b/sysdeps/unix/sysv/linux/arc/libc.abilist
@@ -2427,5 +2427,6 @@ GLIBC_2.38 __isoc23_wcstoull_l F
GLIBC_2.38 __isoc23_wcstoumax F
GLIBC_2.38 __isoc23_wscanf F
GLIBC_2.38 pidfd_fork F
+GLIBC_2.38 pidfd_getpid F
GLIBC_2.38 pidfd_spawn F
GLIBC_2.38 pidfd_spawnp F
diff --git a/sysdeps/unix/sysv/linux/arm/be/libc.abilist b/sysdeps/unix/sysv/linux/arm/be/libc.abilist
index f348336ee7..2344b8ae48 100644
--- a/sysdeps/unix/sysv/linux/arm/be/libc.abilist
+++ b/sysdeps/unix/sysv/linux/arm/be/libc.abilist
@@ -547,6 +547,7 @@ GLIBC_2.38 __isoc23_wcstoull_l F
GLIBC_2.38 __isoc23_wcstoumax F
GLIBC_2.38 __isoc23_wscanf F
GLIBC_2.38 pidfd_fork F
+GLIBC_2.38 pidfd_getpid F
GLIBC_2.38 pidfd_spawn F
GLIBC_2.38 pidfd_spawnp F
GLIBC_2.4 _Exit F
diff --git a/sysdeps/unix/sysv/linux/arm/le/libc.abilist b/sysdeps/unix/sysv/linux/arm/le/libc.abilist
index 5aed593521..b34ec3e9cc 100644
--- a/sysdeps/unix/sysv/linux/arm/le/libc.abilist
+++ b/sysdeps/unix/sysv/linux/arm/le/libc.abilist
@@ -544,6 +544,7 @@ GLIBC_2.38 __isoc23_wcstoull_l F
GLIBC_2.38 __isoc23_wcstoumax F
GLIBC_2.38 __isoc23_wscanf F
GLIBC_2.38 pidfd_fork F
+GLIBC_2.38 pidfd_getpid F
GLIBC_2.38 pidfd_spawn F
GLIBC_2.38 pidfd_spawnp F
GLIBC_2.4 _Exit F
diff --git a/sysdeps/unix/sysv/linux/csky/libc.abilist b/sysdeps/unix/sysv/linux/csky/libc.abilist
index 8a7022aaa8..f59d84fdb0 100644
--- a/sysdeps/unix/sysv/linux/csky/libc.abilist
+++ b/sysdeps/unix/sysv/linux/csky/libc.abilist
@@ -2703,5 +2703,6 @@ GLIBC_2.38 __isoc23_wcstoull_l F
GLIBC_2.38 __isoc23_wcstoumax F
GLIBC_2.38 __isoc23_wscanf F
GLIBC_2.38 pidfd_fork F
+GLIBC_2.38 pidfd_getpid F
GLIBC_2.38 pidfd_spawn F
GLIBC_2.38 pidfd_spawnp F
diff --git a/sysdeps/unix/sysv/linux/hppa/libc.abilist b/sysdeps/unix/sysv/linux/hppa/libc.abilist
index e2ac6949df..f6527bb9db 100644
--- a/sysdeps/unix/sysv/linux/hppa/libc.abilist
+++ b/sysdeps/unix/sysv/linux/hppa/libc.abilist
@@ -2652,6 +2652,7 @@ GLIBC_2.38 __isoc23_wcstoull_l F
GLIBC_2.38 __isoc23_wcstoumax F
GLIBC_2.38 __isoc23_wscanf F
GLIBC_2.38 pidfd_fork F
+GLIBC_2.38 pidfd_getpid F
GLIBC_2.38 pidfd_spawn F
GLIBC_2.38 pidfd_spawnp F
GLIBC_2.4 __confstr_chk F
diff --git a/sysdeps/unix/sysv/linux/i386/libc.abilist b/sysdeps/unix/sysv/linux/i386/libc.abilist
index 5e8d49fc1f..28ccb54206 100644
--- a/sysdeps/unix/sysv/linux/i386/libc.abilist
+++ b/sysdeps/unix/sysv/linux/i386/libc.abilist
@@ -2836,6 +2836,7 @@ GLIBC_2.38 __isoc23_wcstoull_l F
GLIBC_2.38 __isoc23_wcstoumax F
GLIBC_2.38 __isoc23_wscanf F
GLIBC_2.38 pidfd_fork F
+GLIBC_2.38 pidfd_getpid F
GLIBC_2.38 pidfd_spawn F
GLIBC_2.38 pidfd_spawnp F
GLIBC_2.4 __confstr_chk F
diff --git a/sysdeps/unix/sysv/linux/ia64/libc.abilist b/sysdeps/unix/sysv/linux/ia64/libc.abilist
index 3cd3c80334..aabf217819 100644
--- a/sysdeps/unix/sysv/linux/ia64/libc.abilist
+++ b/sysdeps/unix/sysv/linux/ia64/libc.abilist
@@ -2601,6 +2601,7 @@ GLIBC_2.38 __isoc23_wcstoull_l F
GLIBC_2.38 __isoc23_wcstoumax F
GLIBC_2.38 __isoc23_wscanf F
GLIBC_2.38 pidfd_fork F
+GLIBC_2.38 pidfd_getpid F
GLIBC_2.38 pidfd_spawn F
GLIBC_2.38 pidfd_spawnp F
GLIBC_2.4 __confstr_chk F
diff --git a/sysdeps/unix/sysv/linux/loongarch/lp64/libc.abilist b/sysdeps/unix/sysv/linux/loongarch/lp64/libc.abilist
index 0965db2ff0..8b53d82e8c 100644
--- a/sysdeps/unix/sysv/linux/loongarch/lp64/libc.abilist
+++ b/sysdeps/unix/sysv/linux/loongarch/lp64/libc.abilist
@@ -2187,5 +2187,6 @@ GLIBC_2.38 __isoc23_wcstoull_l F
GLIBC_2.38 __isoc23_wcstoumax F
GLIBC_2.38 __isoc23_wscanf F
GLIBC_2.38 pidfd_fork F
+GLIBC_2.38 pidfd_getpid F
GLIBC_2.38 pidfd_spawn F
GLIBC_2.38 pidfd_spawnp F
diff --git a/sysdeps/unix/sysv/linux/m68k/coldfire/libc.abilist b/sysdeps/unix/sysv/linux/m68k/coldfire/libc.abilist
index 1ec24886a3..66bf4532ab 100644
--- a/sysdeps/unix/sysv/linux/m68k/coldfire/libc.abilist
+++ b/sysdeps/unix/sysv/linux/m68k/coldfire/libc.abilist
@@ -548,6 +548,7 @@ GLIBC_2.38 __isoc23_wcstoull_l F
GLIBC_2.38 __isoc23_wcstoumax F
GLIBC_2.38 __isoc23_wscanf F
GLIBC_2.38 pidfd_fork F
+GLIBC_2.38 pidfd_getpid F
GLIBC_2.38 pidfd_spawn F
GLIBC_2.38 pidfd_spawnp F
GLIBC_2.4 _Exit F
diff --git a/sysdeps/unix/sysv/linux/m68k/m680x0/libc.abilist b/sysdeps/unix/sysv/linux/m68k/m680x0/libc.abilist
index 239b1d70be..0ee9fef825 100644
--- a/sysdeps/unix/sysv/linux/m68k/m680x0/libc.abilist
+++ b/sysdeps/unix/sysv/linux/m68k/m680x0/libc.abilist
@@ -2779,6 +2779,7 @@ GLIBC_2.38 __isoc23_wcstoull_l F
GLIBC_2.38 __isoc23_wcstoumax F
GLIBC_2.38 __isoc23_wscanf F
GLIBC_2.38 pidfd_fork F
+GLIBC_2.38 pidfd_getpid F
GLIBC_2.38 pidfd_spawn F
GLIBC_2.38 pidfd_spawnp F
GLIBC_2.4 __confstr_chk F
diff --git a/sysdeps/unix/sysv/linux/microblaze/be/libc.abilist b/sysdeps/unix/sysv/linux/microblaze/be/libc.abilist
index dd41d63394..8861ebb4ca 100644
--- a/sysdeps/unix/sysv/linux/microblaze/be/libc.abilist
+++ b/sysdeps/unix/sysv/linux/microblaze/be/libc.abilist
@@ -2752,5 +2752,6 @@ GLIBC_2.38 __isoc23_wcstoull_l F
GLIBC_2.38 __isoc23_wcstoumax F
GLIBC_2.38 __isoc23_wscanf F
GLIBC_2.38 pidfd_fork F
+GLIBC_2.38 pidfd_getpid F
GLIBC_2.38 pidfd_spawn F
GLIBC_2.38 pidfd_spawnp F
diff --git a/sysdeps/unix/sysv/linux/microblaze/le/libc.abilist b/sysdeps/unix/sysv/linux/microblaze/le/libc.abilist
index 55c3dcd471..008dda3746 100644
--- a/sysdeps/unix/sysv/linux/microblaze/le/libc.abilist
+++ b/sysdeps/unix/sysv/linux/microblaze/le/libc.abilist
@@ -2749,5 +2749,6 @@ GLIBC_2.38 __isoc23_wcstoull_l F
GLIBC_2.38 __isoc23_wcstoumax F
GLIBC_2.38 __isoc23_wscanf F
GLIBC_2.38 pidfd_fork F
+GLIBC_2.38 pidfd_getpid F
GLIBC_2.38 pidfd_spawn F
GLIBC_2.38 pidfd_spawnp F
diff --git a/sysdeps/unix/sysv/linux/mips/mips32/fpu/libc.abilist b/sysdeps/unix/sysv/linux/mips/mips32/fpu/libc.abilist
index 295e4d8608..2d0af493ed 100644
--- a/sysdeps/unix/sysv/linux/mips/mips32/fpu/libc.abilist
+++ b/sysdeps/unix/sysv/linux/mips/mips32/fpu/libc.abilist
@@ -2744,6 +2744,7 @@ GLIBC_2.38 __isoc23_wcstoull_l F
GLIBC_2.38 __isoc23_wcstoumax F
GLIBC_2.38 __isoc23_wscanf F
GLIBC_2.38 pidfd_fork F
+GLIBC_2.38 pidfd_getpid F
GLIBC_2.38 pidfd_spawn F
GLIBC_2.38 pidfd_spawnp F
GLIBC_2.4 __confstr_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 19fb1aebe7..ae82d18edb 100644
--- a/sysdeps/unix/sysv/linux/mips/mips32/nofpu/libc.abilist
+++ b/sysdeps/unix/sysv/linux/mips/mips32/nofpu/libc.abilist
@@ -2742,6 +2742,7 @@ GLIBC_2.38 __isoc23_wcstoull_l F
GLIBC_2.38 __isoc23_wcstoumax F
GLIBC_2.38 __isoc23_wscanf F
GLIBC_2.38 pidfd_fork F
+GLIBC_2.38 pidfd_getpid F
GLIBC_2.38 pidfd_spawn F
GLIBC_2.38 pidfd_spawnp F
GLIBC_2.4 __confstr_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 2dd6ef5416..87aee7f86d 100644
--- a/sysdeps/unix/sysv/linux/mips/mips64/n32/libc.abilist
+++ b/sysdeps/unix/sysv/linux/mips/mips64/n32/libc.abilist
@@ -2750,6 +2750,7 @@ GLIBC_2.38 __isoc23_wcstoull_l F
GLIBC_2.38 __isoc23_wcstoumax F
GLIBC_2.38 __isoc23_wscanf F
GLIBC_2.38 pidfd_fork F
+GLIBC_2.38 pidfd_getpid F
GLIBC_2.38 pidfd_spawn F
GLIBC_2.38 pidfd_spawnp F
GLIBC_2.4 __confstr_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 6445d27220..c0d1fd370a 100644
--- a/sysdeps/unix/sysv/linux/mips/mips64/n64/libc.abilist
+++ b/sysdeps/unix/sysv/linux/mips/mips64/n64/libc.abilist
@@ -2652,6 +2652,7 @@ GLIBC_2.38 __isoc23_wcstoull_l F
GLIBC_2.38 __isoc23_wcstoumax F
GLIBC_2.38 __isoc23_wscanf F
GLIBC_2.38 pidfd_fork F
+GLIBC_2.38 pidfd_getpid F
GLIBC_2.38 pidfd_spawn F
GLIBC_2.38 pidfd_spawnp F
GLIBC_2.4 __confstr_chk F
diff --git a/sysdeps/unix/sysv/linux/nios2/libc.abilist b/sysdeps/unix/sysv/linux/nios2/libc.abilist
index c1cc5134c9..06092621b9 100644
--- a/sysdeps/unix/sysv/linux/nios2/libc.abilist
+++ b/sysdeps/unix/sysv/linux/nios2/libc.abilist
@@ -2791,5 +2791,6 @@ GLIBC_2.38 __isoc23_wcstoull_l F
GLIBC_2.38 __isoc23_wcstoumax F
GLIBC_2.38 __isoc23_wscanf F
GLIBC_2.38 pidfd_fork F
+GLIBC_2.38 pidfd_getpid F
GLIBC_2.38 pidfd_spawn F
GLIBC_2.38 pidfd_spawnp F
diff --git a/sysdeps/unix/sysv/linux/or1k/libc.abilist b/sysdeps/unix/sysv/linux/or1k/libc.abilist
index 293643346a..88dcdd8b98 100644
--- a/sysdeps/unix/sysv/linux/or1k/libc.abilist
+++ b/sysdeps/unix/sysv/linux/or1k/libc.abilist
@@ -2173,5 +2173,6 @@ GLIBC_2.38 __isoc23_wcstoull_l F
GLIBC_2.38 __isoc23_wcstoumax F
GLIBC_2.38 __isoc23_wscanf F
GLIBC_2.38 pidfd_fork F
+GLIBC_2.38 pidfd_getpid F
GLIBC_2.38 pidfd_spawn F
GLIBC_2.38 pidfd_spawnp F
diff --git a/sysdeps/unix/sysv/linux/pidfd_getpid.c b/sysdeps/unix/sysv/linux/pidfd_getpid.c
new file mode 100644
index 0000000000..09cd81f863
--- /dev/null
+++ b/sysdeps/unix/sysv/linux/pidfd_getpid.c
@@ -0,0 +1,70 @@
+/* pidfd_getpid - Get the associated pid from the pid file descriptor.
+ Copyright (C) 2023 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/>. */
+
+#include <_itoa.h>
+#include <errno.h>
+#include <intprops.h>
+#include <procutils.h>
+#include <string.h>
+#include <unistd.h>
+#include <stdlib.h>
+
+#define FDINFO_TO_FILENAME_PREFIX "/proc/self/fdinfo/"
+
+#define FDINFO_FILENAME_LEN \
+ (sizeof (FDINFO_TO_FILENAME_PREFIX) + INT_STRLEN_BOUND (int))
+
+static bool
+parse_fdinfo (const char *l, void *arg)
+{
+ enum { fieldlen = sizeof ("Pid:") - 1 };
+ if (strncmp (l, "Pid:", fieldlen) != 0)
+ return true;
+
+ l += fieldlen;
+
+ char *endp;
+ unsigned long int n = strtoul (l, &endp, 10);
+ if (l == endp || n > INT_MAX)
+ return true;
+
+ *(pid_t *)arg = n;
+ return false;
+}
+
+pid_t
+pidfd_getpid (int fd)
+{
+ if (__glibc_unlikely (fd < 0))
+ {
+ __set_errno (EINVAL);
+ return -1;
+ }
+
+ char fdinfoname[FDINFO_FILENAME_LEN];
+
+ char *p = mempcpy (fdinfoname, FDINFO_TO_FILENAME_PREFIX,
+ strlen (FDINFO_TO_FILENAME_PREFIX));
+ *_fitoa_word (fd, p, 10, 0) = '\0';
+
+ pid_t pid;
+ if (procutils_read_file (fdinfoname, parse_fdinfo, &pid) == -1)
+ return -1;
+
+ return pid;
+}
diff --git a/sysdeps/unix/sysv/linux/powerpc/powerpc32/fpu/libc.abilist b/sysdeps/unix/sysv/linux/powerpc/powerpc32/fpu/libc.abilist
index 03a35e860d..ce885f9136 100644
--- a/sysdeps/unix/sysv/linux/powerpc/powerpc32/fpu/libc.abilist
+++ b/sysdeps/unix/sysv/linux/powerpc/powerpc32/fpu/libc.abilist
@@ -2818,6 +2818,7 @@ GLIBC_2.38 __nldbl___isoc23_vswscanf F
GLIBC_2.38 __nldbl___isoc23_vwscanf F
GLIBC_2.38 __nldbl___isoc23_wscanf F
GLIBC_2.38 pidfd_fork F
+GLIBC_2.38 pidfd_getpid F
GLIBC_2.38 pidfd_spawn F
GLIBC_2.38 pidfd_spawnp F
GLIBC_2.4 _IO_fprintf F
diff --git a/sysdeps/unix/sysv/linux/powerpc/powerpc32/nofpu/libc.abilist b/sysdeps/unix/sysv/linux/powerpc/powerpc32/nofpu/libc.abilist
index a91af4245b..8063a0606e 100644
--- a/sysdeps/unix/sysv/linux/powerpc/powerpc32/nofpu/libc.abilist
+++ b/sysdeps/unix/sysv/linux/powerpc/powerpc32/nofpu/libc.abilist
@@ -2851,6 +2851,7 @@ GLIBC_2.38 __nldbl___isoc23_vswscanf F
GLIBC_2.38 __nldbl___isoc23_vwscanf F
GLIBC_2.38 __nldbl___isoc23_wscanf F
GLIBC_2.38 pidfd_fork F
+GLIBC_2.38 pidfd_getpid F
GLIBC_2.38 pidfd_spawn F
GLIBC_2.38 pidfd_spawnp F
GLIBC_2.4 _IO_fprintf F
diff --git a/sysdeps/unix/sysv/linux/powerpc/powerpc64/be/libc.abilist b/sysdeps/unix/sysv/linux/powerpc/powerpc64/be/libc.abilist
index c15137b9ad..21fb95a352 100644
--- a/sysdeps/unix/sysv/linux/powerpc/powerpc64/be/libc.abilist
+++ b/sysdeps/unix/sysv/linux/powerpc/powerpc64/be/libc.abilist
@@ -2572,6 +2572,7 @@ GLIBC_2.38 __nldbl___isoc23_vswscanf F
GLIBC_2.38 __nldbl___isoc23_vwscanf F
GLIBC_2.38 __nldbl___isoc23_wscanf F
GLIBC_2.38 pidfd_fork F
+GLIBC_2.38 pidfd_getpid F
GLIBC_2.38 pidfd_spawn F
GLIBC_2.38 pidfd_spawnp F
GLIBC_2.4 _IO_fprintf F
diff --git a/sysdeps/unix/sysv/linux/powerpc/powerpc64/le/libc.abilist b/sysdeps/unix/sysv/linux/powerpc/powerpc64/le/libc.abilist
index 12c0f4cfba..14bda5b5b8 100644
--- a/sysdeps/unix/sysv/linux/powerpc/powerpc64/le/libc.abilist
+++ b/sysdeps/unix/sysv/linux/powerpc/powerpc64/le/libc.abilist
@@ -2886,5 +2886,6 @@ GLIBC_2.38 __nldbl___isoc23_vswscanf F
GLIBC_2.38 __nldbl___isoc23_vwscanf F
GLIBC_2.38 __nldbl___isoc23_wscanf F
GLIBC_2.38 pidfd_fork F
+GLIBC_2.38 pidfd_getpid F
GLIBC_2.38 pidfd_spawn F
GLIBC_2.38 pidfd_spawnp F
diff --git a/sysdeps/unix/sysv/linux/procutils.c b/sysdeps/unix/sysv/linux/procutils.c
new file mode 100644
index 0000000000..4909afeae1
--- /dev/null
+++ b/sysdeps/unix/sysv/linux/procutils.c
@@ -0,0 +1,99 @@
+/* Utilities functions to read/parse Linux procfs and sysfs.
+ Copyright (C) 2023 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/>. */
+
+#include <assert.h>
+#include <not-cancel.h>
+#include <procutils.h>
+#include <string.h>
+
+static char *
+next_line (int fd, char *const buffer, char **cp, char **re,
+ char *const buffer_end)
+{
+ char *res = *cp;
+ char *nl = memchr (*cp, '\n', *re - *cp);
+ if (nl == NULL)
+ {
+ if (*cp != buffer)
+ {
+ if (*re == buffer_end)
+ {
+ memmove (buffer, *cp, *re - *cp);
+ *re = buffer + (*re - *cp);
+ *cp = buffer;
+
+ ssize_t n = __read_nocancel (fd, *re, buffer_end - *re);
+ if (n < 0)
+ return NULL;
+
+ *re += n;
+
+ nl = memchr (*cp, '\n', *re - *cp);
+ while (nl == NULL && *re == buffer_end)
+ {
+ /* Truncate too long lines. */
+ *re = buffer + 3 * (buffer_end - buffer) / 4;
+ n = __read_nocancel (fd, *re, buffer_end - *re);
+ if (n < 0)
+ return NULL;
+
+ nl = memchr (*re, '\n', n);
+ **re = '\0';
+ *re += n;
+ }
+ }
+ else
+ nl = memchr (*cp, '\n', *re - *cp);
+
+ res = *cp;
+ }
+
+ if (nl == NULL)
+ nl = *re - 1;
+ }
+
+ *nl = '\0';
+ *cp = nl + 1;
+ assert (*cp <= *re);
+
+ return res == *re ? NULL : res;
+}
+
+int
+procutils_read_file (const char *filename, procutils_closure_t closure,
+ void *arg)
+{
+ enum { buffer_size = 1024 };
+ char buffer[buffer_size];
+ char *buffer_end = buffer + buffer_size;
+ char *cp = buffer_end;
+ char *re = buffer_end;
+
+ int fd = __open64_nocancel (filename, O_RDONLY | O_CLOEXEC);
+ if (fd == -1)
+ return -1;
+
+ char *l;
+ while ((l = next_line (fd, buffer, &cp, &re, buffer_end)) != NULL)
+ if (!closure (l, arg))
+ break;
+
+ __close_nocancel_nostatus (fd);
+
+ return 0;
+}
diff --git a/sysdeps/unix/sysv/linux/procutils.h b/sysdeps/unix/sysv/linux/procutils.h
new file mode 100644
index 0000000000..afb2d43bed
--- /dev/null
+++ b/sysdeps/unix/sysv/linux/procutils.h
@@ -0,0 +1,37 @@
+/* Utilities functions to read/parse Linux procfs and sysfs.
+ Copyright (C) 2023 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 _PROCUTILS_H
+#define _PROCUTILS_H
+
+#include <stdbool.h>
+
+typedef bool (*procutils_closure_t)(const char *line, void *arg);
+
+/* Open and read the path FILENAME, line per line, and call CLOSURE with
+ argument ARG on each line. The read is done with a static buffer,
+ with non-cancellable calls, and the line is null terminated.
+
+ The CLOSURE should return false if the read should continue, or false
+ if the function should stop.
+
+ It returns 0 in case of success, or -1 otherwise. */
+int procutils_read_file (const char *filename, procutils_closure_t closure,
+ void *arg) attribute_hidden;
+
+#endif
diff --git a/sysdeps/unix/sysv/linux/riscv/rv32/libc.abilist b/sysdeps/unix/sysv/linux/riscv/rv32/libc.abilist
index 9537dac42d..b294ec1021 100644
--- a/sysdeps/unix/sysv/linux/riscv/rv32/libc.abilist
+++ b/sysdeps/unix/sysv/linux/riscv/rv32/libc.abilist
@@ -2429,5 +2429,6 @@ GLIBC_2.38 __isoc23_wcstoull_l F
GLIBC_2.38 __isoc23_wcstoumax F
GLIBC_2.38 __isoc23_wscanf F
GLIBC_2.38 pidfd_fork F
+GLIBC_2.38 pidfd_getpid F
GLIBC_2.38 pidfd_spawn F
GLIBC_2.38 pidfd_spawnp F
diff --git a/sysdeps/unix/sysv/linux/riscv/rv64/libc.abilist b/sysdeps/unix/sysv/linux/riscv/rv64/libc.abilist
index ea72e6b648..61921a02d4 100644
--- a/sysdeps/unix/sysv/linux/riscv/rv64/libc.abilist
+++ b/sysdeps/unix/sysv/linux/riscv/rv64/libc.abilist
@@ -2629,5 +2629,6 @@ GLIBC_2.38 __isoc23_wcstoull_l F
GLIBC_2.38 __isoc23_wcstoumax F
GLIBC_2.38 __isoc23_wscanf F
GLIBC_2.38 pidfd_fork F
+GLIBC_2.38 pidfd_getpid F
GLIBC_2.38 pidfd_spawn F
GLIBC_2.38 pidfd_spawnp F
diff --git a/sysdeps/unix/sysv/linux/s390/s390-32/libc.abilist b/sysdeps/unix/sysv/linux/s390/s390-32/libc.abilist
index d6c895b487..fbc2d5826f 100644
--- a/sysdeps/unix/sysv/linux/s390/s390-32/libc.abilist
+++ b/sysdeps/unix/sysv/linux/s390/s390-32/libc.abilist
@@ -2816,6 +2816,7 @@ GLIBC_2.38 __nldbl___isoc23_vswscanf F
GLIBC_2.38 __nldbl___isoc23_vwscanf F
GLIBC_2.38 __nldbl___isoc23_wscanf F
GLIBC_2.38 pidfd_fork F
+GLIBC_2.38 pidfd_getpid F
GLIBC_2.38 pidfd_spawn F
GLIBC_2.38 pidfd_spawnp F
GLIBC_2.4 _IO_fprintf F
diff --git a/sysdeps/unix/sysv/linux/s390/s390-64/libc.abilist b/sysdeps/unix/sysv/linux/s390/s390-64/libc.abilist
index b375f5a7ab..45ab26d7a7 100644
--- a/sysdeps/unix/sysv/linux/s390/s390-64/libc.abilist
+++ b/sysdeps/unix/sysv/linux/s390/s390-64/libc.abilist
@@ -2609,6 +2609,7 @@ GLIBC_2.38 __nldbl___isoc23_vswscanf F
GLIBC_2.38 __nldbl___isoc23_vwscanf F
GLIBC_2.38 __nldbl___isoc23_wscanf F
GLIBC_2.38 pidfd_fork F
+GLIBC_2.38 pidfd_getpid F
GLIBC_2.38 pidfd_spawn F
GLIBC_2.38 pidfd_spawnp F
GLIBC_2.4 _IO_fprintf F
diff --git a/sysdeps/unix/sysv/linux/sh/be/libc.abilist b/sysdeps/unix/sysv/linux/sh/be/libc.abilist
index 7b2266ecb3..8de69e0057 100644
--- a/sysdeps/unix/sysv/linux/sh/be/libc.abilist
+++ b/sysdeps/unix/sysv/linux/sh/be/libc.abilist
@@ -2659,6 +2659,7 @@ GLIBC_2.38 __isoc23_wcstoull_l F
GLIBC_2.38 __isoc23_wcstoumax F
GLIBC_2.38 __isoc23_wscanf F
GLIBC_2.38 pidfd_fork F
+GLIBC_2.38 pidfd_getpid F
GLIBC_2.38 pidfd_spawn F
GLIBC_2.38 pidfd_spawnp F
GLIBC_2.4 __confstr_chk F
diff --git a/sysdeps/unix/sysv/linux/sh/le/libc.abilist b/sysdeps/unix/sysv/linux/sh/le/libc.abilist
index 2f9f732044..3821ce3676 100644
--- a/sysdeps/unix/sysv/linux/sh/le/libc.abilist
+++ b/sysdeps/unix/sysv/linux/sh/le/libc.abilist
@@ -2656,6 +2656,7 @@ GLIBC_2.38 __isoc23_wcstoull_l F
GLIBC_2.38 __isoc23_wcstoumax F
GLIBC_2.38 __isoc23_wscanf F
GLIBC_2.38 pidfd_fork F
+GLIBC_2.38 pidfd_getpid F
GLIBC_2.38 pidfd_spawn F
GLIBC_2.38 pidfd_spawnp F
GLIBC_2.4 __confstr_chk F
diff --git a/sysdeps/unix/sysv/linux/sparc/sparc32/libc.abilist b/sysdeps/unix/sysv/linux/sparc/sparc32/libc.abilist
index 144d54ebf2..7be5b0c125 100644
--- a/sysdeps/unix/sysv/linux/sparc/sparc32/libc.abilist
+++ b/sysdeps/unix/sysv/linux/sparc/sparc32/libc.abilist
@@ -2811,6 +2811,7 @@ GLIBC_2.38 __nldbl___isoc23_vswscanf F
GLIBC_2.38 __nldbl___isoc23_vwscanf F
GLIBC_2.38 __nldbl___isoc23_wscanf F
GLIBC_2.38 pidfd_fork F
+GLIBC_2.38 pidfd_getpid F
GLIBC_2.38 pidfd_spawn F
GLIBC_2.38 pidfd_spawnp F
GLIBC_2.4 _IO_fprintf F
diff --git a/sysdeps/unix/sysv/linux/sparc/sparc64/libc.abilist b/sysdeps/unix/sysv/linux/sparc/sparc64/libc.abilist
index bc8bd8ff54..a09b2efc90 100644
--- a/sysdeps/unix/sysv/linux/sparc/sparc64/libc.abilist
+++ b/sysdeps/unix/sysv/linux/sparc/sparc64/libc.abilist
@@ -2624,6 +2624,7 @@ GLIBC_2.38 __isoc23_wcstoull_l F
GLIBC_2.38 __isoc23_wcstoumax F
GLIBC_2.38 __isoc23_wscanf F
GLIBC_2.38 pidfd_fork F
+GLIBC_2.38 pidfd_getpid F
GLIBC_2.38 pidfd_spawn F
GLIBC_2.38 pidfd_spawnp F
GLIBC_2.4 __confstr_chk F
diff --git a/sysdeps/unix/sysv/linux/sys/pidfd.h b/sysdeps/unix/sysv/linux/sys/pidfd.h
index ed1d3b0ab4..f111a7d8d6 100644
--- a/sysdeps/unix/sysv/linux/sys/pidfd.h
+++ b/sysdeps/unix/sysv/linux/sys/pidfd.h
@@ -59,4 +59,8 @@ extern int pidfd_send_signal (int __pidfd, int __sig, siginfo_t *__info,
of the new process to the parent process. */
extern int pidfd_fork (unsigned int __flags) __THROW;
+/* Query the process ID (PID) from process descriptor __FD. Return the PID
+ or -1 in case of an error. */
+extern pid_t pidfd_getpid (int __fd) __THROW;
+
#endif /* _PIDFD_H */
diff --git a/sysdeps/unix/sysv/linux/tst-pidfd.c b/sysdeps/unix/sysv/linux/tst-pidfd.c
index 64d8a2ef40..39d86fb668 100644
--- a/sysdeps/unix/sysv/linux/tst-pidfd.c
+++ b/sysdeps/unix/sysv/linux/tst-pidfd.c
@@ -18,6 +18,7 @@
#include <errno.h>
#include <fcntl.h>
+#include <limits.h>
#include <support/capture_subprocess.h>
#include <support/check.h>
#include <support/process_state.h>
@@ -118,6 +119,12 @@ do_test (void)
int pidfd = pidfd_open (pid, 0);
TEST_VERIFY (pidfd != -1);
+ TEST_COMPARE (pidfd_getpid (INT_MAX), -1);
+ {
+ pid_t querypid = pidfd_getpid (pidfd);
+ TEST_COMPARE (querypid, pid);
+ }
+
/* Wait for first sigtimedwait. */
support_process_state_wait (pid, support_process_state_sleeping);
TEST_COMPARE (pidfd_send_signal (pidfd, SIGUSR1, NULL, 0), 0);
diff --git a/sysdeps/unix/sysv/linux/x86_64/64/libc.abilist b/sysdeps/unix/sysv/linux/x86_64/64/libc.abilist
index 045205de0c..0726b6e8d0 100644
--- a/sysdeps/unix/sysv/linux/x86_64/64/libc.abilist
+++ b/sysdeps/unix/sysv/linux/x86_64/64/libc.abilist
@@ -2575,6 +2575,7 @@ GLIBC_2.38 __isoc23_wcstoull_l F
GLIBC_2.38 __isoc23_wcstoumax F
GLIBC_2.38 __isoc23_wscanf F
GLIBC_2.38 pidfd_fork F
+GLIBC_2.38 pidfd_getpid F
GLIBC_2.38 pidfd_spawn F
GLIBC_2.38 pidfd_spawnp F
GLIBC_2.4 __confstr_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 5a67604948..9c1f6830ba 100644
--- a/sysdeps/unix/sysv/linux/x86_64/x32/libc.abilist
+++ b/sysdeps/unix/sysv/linux/x86_64/x32/libc.abilist
@@ -2681,5 +2681,6 @@ GLIBC_2.38 __isoc23_wcstoull_l F
GLIBC_2.38 __isoc23_wcstoumax F
GLIBC_2.38 __isoc23_wscanf F
GLIBC_2.38 pidfd_fork F
+GLIBC_2.38 pidfd_getpid F
GLIBC_2.38 pidfd_spawn F
GLIBC_2.38 pidfd_spawnp F
--
2.34.1
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