Linux: Add epoll_pwait2

Message ID 20220112193702.2901382-1-adhemerval.zanella@linaro.org
State Committed
Headers
Series Linux: Add epoll_pwait2 |

Checks

Context Check Description
dj/TryBot-apply_patch success Patch applied to master at the time it was sent
dj/TryBot-32bit success Build for i686

Commit Message

Adhemerval Zanella Jan. 12, 2022, 7:37 p.m. UTC
  It is similar to epoll_wait, with the difference the timeout has
nanosecond resoluting by using struct timespec instead of int.

Although Linux interface only provides 64 bit time_t support, old
32 bit interface is also provided (so keep in sync with current
practice and to no force opt-in on 64 bit time_t).

Checked on x86_64-linux-gnu and i686-linux-gnu.
---
 NEWS                                          |   3 +
 include/sys/epoll.h                           |   8 +
 sysdeps/unix/sysv/linux/Makefile              |   4 +-
 sysdeps/unix/sysv/linux/Versions              |   6 +
 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   |   2 +
 sysdeps/unix/sysv/linux/arm/le/libc.abilist   |   2 +
 sysdeps/unix/sysv/linux/csky/libc.abilist     |   2 +
 sysdeps/unix/sysv/linux/epoll_pwait2.c        |  44 ++++
 sysdeps/unix/sysv/linux/hppa/libc.abilist     |   2 +
 sysdeps/unix/sysv/linux/i386/libc.abilist     |   2 +
 sysdeps/unix/sysv/linux/ia64/libc.abilist     |   1 +
 .../sysv/linux/m68k/coldfire/libc.abilist     |   2 +
 .../unix/sysv/linux/m68k/m680x0/libc.abilist  |   2 +
 .../sysv/linux/microblaze/be/libc.abilist     |   2 +
 .../sysv/linux/microblaze/le/libc.abilist     |   2 +
 .../sysv/linux/mips/mips32/fpu/libc.abilist   |   2 +
 .../sysv/linux/mips/mips32/nofpu/libc.abilist |   2 +
 .../sysv/linux/mips/mips64/n32/libc.abilist   |   2 +
 .../sysv/linux/mips/mips64/n64/libc.abilist   |   1 +
 sysdeps/unix/sysv/linux/nios2/libc.abilist    |   2 +
 sysdeps/unix/sysv/linux/or1k/libc.abilist     |   1 +
 .../linux/powerpc/powerpc32/fpu/libc.abilist  |   2 +
 .../powerpc/powerpc32/nofpu/libc.abilist      |   2 +
 .../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 |   2 +
 .../unix/sysv/linux/s390/s390-64/libc.abilist |   1 +
 sysdeps/unix/sysv/linux/sh/be/libc.abilist    |   2 +
 sysdeps/unix/sysv/linux/sh/le/libc.abilist    |   2 +
 .../sysv/linux/sparc/sparc32/libc.abilist     |   2 +
 .../sysv/linux/sparc/sparc64/libc.abilist     |   1 +
 sysdeps/unix/sysv/linux/sys/epoll.h           |  21 ++
 sysdeps/unix/sysv/linux/tst-epoll-time64.c    |   1 +
 sysdeps/unix/sysv/linux/tst-epoll.c           | 217 ++++++++++++++++++
 .../unix/sysv/linux/x86_64/64/libc.abilist    |   1 +
 .../unix/sysv/linux/x86_64/x32/libc.abilist   |   1 +
 41 files changed, 355 insertions(+), 1 deletion(-)
 create mode 100644 sysdeps/unix/sysv/linux/epoll_pwait2.c
 create mode 100644 sysdeps/unix/sysv/linux/tst-epoll-time64.c
 create mode 100644 sysdeps/unix/sysv/linux/tst-epoll.c
  

Comments

Florian Weimer Jan. 13, 2022, 10:07 a.m. UTC | #1
* Adhemerval Zanella via Libc-alpha:

> It is similar to epoll_wait, with the difference the timeout has
> nanosecond resoluting by using struct timespec instead of int.
>
> Although Linux interface only provides 64 bit time_t support, old
> 32 bit interface is also provided (so keep in sync with current
> practice and to no force opt-in on 64 bit time_t).
>
> Checked on x86_64-linux-gnu and i686-linux-gnu.

Patch looks okay to me, but this probably needs RM approval.

Reviewed-by: Florian Weimer <fweimer@redhat.com>

Carlos?

Thanks,
Florian
  
Carlos O'Donell Jan. 17, 2022, 2:30 p.m. UTC | #2
On 1/13/22 05:07, Florian Weimer wrote:
> * Adhemerval Zanella via Libc-alpha:
> 
>> It is similar to epoll_wait, with the difference the timeout has
>> nanosecond resoluting by using struct timespec instead of int.
>>
>> Although Linux interface only provides 64 bit time_t support, old
>> 32 bit interface is also provided (so keep in sync with current
>> practice and to no force opt-in on 64 bit time_t).
>>
>> Checked on x86_64-linux-gnu and i686-linux-gnu.
> 
> Patch looks okay to me, but this probably needs RM approval.
> 
> Reviewed-by: Florian Weimer <fweimer@redhat.com>
> 
> Carlos?

Approved for glibc 2.35.

Syscall wrappers are very narrow ABI additions and enabling new syscalls
is important enough.
  

Patch

diff --git a/NEWS b/NEWS
index a957b19fdc..5e670afbbf 100644
--- a/NEWS
+++ b/NEWS
@@ -120,6 +120,9 @@  Major new features:
   The OpenRISC ABI is 32-bit big-endian and uses 64-bit time (y2038 safe) and
   64-bit file offsets (LFS default).
 
+* On Linux, the epoll_pwait2 function has been added.  It is similar to
+  epoll_wait with the difference the timeout has nanoseconds resolution.
+
 Deprecated and removed features, and other changes affecting compatibility:
 
 * On x86-64, the LD_PREFER_MAP_32BIT_EXEC environment variable support
diff --git a/include/sys/epoll.h b/include/sys/epoll.h
index 86e0a54e62..8049381a26 100644
--- a/include/sys/epoll.h
+++ b/include/sys/epoll.h
@@ -4,6 +4,14 @@ 
 # ifndef _ISOMAC
 
 libc_hidden_proto (epoll_pwait)
+#if __TIMESIZE == 64
+# define __epoll_pwait2_time64 epoll_pwait2
+#else
+extern int __epoll_pwait2_time64 (int fd, struct epoll_event *ev, int maxev,
+				  const struct __timespec64 *tmo,
+				  const sigset_t *s);
+libc_hidden_proto (__epoll_pwait2_time64)
+#endif
 
 # endif /* !_ISOMAC */
 #endif
diff --git a/sysdeps/unix/sysv/linux/Makefile b/sysdeps/unix/sysv/linux/Makefile
index 61acc1987d..85fc8cbf75 100644
--- a/sysdeps/unix/sysv/linux/Makefile
+++ b/sysdeps/unix/sysv/linux/Makefile
@@ -55,7 +55,7 @@  endif
 
 ifeq ($(subdir),misc)
 sysdep_routines += adjtimex clone umount umount2 readahead sysctl \
-		   setfsuid setfsgid epoll_pwait signalfd \
+		   setfsuid setfsgid epoll_pwait epoll_pwait2 signalfd \
 		   eventfd eventfd_read eventfd_write prlimit prlimit64 \
 		   personality epoll_wait tee vmsplice splice \
 		   open_by_handle_at mlock2 pkey_mprotect pkey_set pkey_get \
@@ -125,6 +125,7 @@  tests += tst-clone tst-clone2 tst-clone3 tst-fanotify tst-personality \
 	 tst-ntp_gettimex tst-sigtimedwait tst-misalign-clone \
   tst-prctl \
   tst-scm_rights \
+  tst-epoll \
   # tests
 
 # Test for the symbol version of fcntl that was replaced in glibc 2.28.
@@ -146,6 +147,7 @@  endif
 tests-time64 += \
   tst-adjtimex-time64 \
   tst-clock_adjtime-time64 \
+  tst-epoll-time64 \
   tst-ntp_adjtime-time64 \
   tst-ntp_gettime-time64 \
   tst-ntp_gettimex-time64 \
diff --git a/sysdeps/unix/sysv/linux/Versions b/sysdeps/unix/sysv/linux/Versions
index 3f8809a158..ded087f30e 100644
--- a/sysdeps/unix/sysv/linux/Versions
+++ b/sysdeps/unix/sysv/linux/Versions
@@ -293,6 +293,12 @@  libc {
 %endif
     close_range;
   }
+  GLIBC_2.35 {
+%ifdef TIME64_NON_DEFAULT
+    __epoll_pwait2_time64;
+%endif
+    epoll_pwait2;
+  }
   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 fed942ed4b..c1a5ee90e6 100644
--- a/sysdeps/unix/sysv/linux/aarch64/libc.abilist
+++ b/sysdeps/unix/sysv/linux/aarch64/libc.abilist
@@ -2614,3 +2614,4 @@  GLIBC_2.34 tss_get F
 GLIBC_2.34 tss_set F
 GLIBC_2.35 __memcmpeq F
 GLIBC_2.35 _dl_find_object F
+GLIBC_2.35 epoll_pwait2 F
diff --git a/sysdeps/unix/sysv/linux/alpha/libc.abilist b/sysdeps/unix/sysv/linux/alpha/libc.abilist
index 2867932704..1a30d0666b 100644
--- a/sysdeps/unix/sysv/linux/alpha/libc.abilist
+++ b/sysdeps/unix/sysv/linux/alpha/libc.abilist
@@ -2711,6 +2711,7 @@  GLIBC_2.34 tss_get F
 GLIBC_2.34 tss_set F
 GLIBC_2.35 __memcmpeq F
 GLIBC_2.35 _dl_find_object F
+GLIBC_2.35 epoll_pwait2 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 239db7bab0..e5dfdab357 100644
--- a/sysdeps/unix/sysv/linux/arc/libc.abilist
+++ b/sysdeps/unix/sysv/linux/arc/libc.abilist
@@ -2375,3 +2375,4 @@  GLIBC_2.34 tss_get F
 GLIBC_2.34 tss_set F
 GLIBC_2.35 __memcmpeq F
 GLIBC_2.35 _dl_find_object F
+GLIBC_2.35 epoll_pwait2 F
diff --git a/sysdeps/unix/sysv/linux/arm/be/libc.abilist b/sysdeps/unix/sysv/linux/arm/be/libc.abilist
index bc79dcfe8a..4d3fd87278 100644
--- a/sysdeps/unix/sysv/linux/arm/be/libc.abilist
+++ b/sysdeps/unix/sysv/linux/arm/be/libc.abilist
@@ -491,8 +491,10 @@  GLIBC_2.34 tss_create F
 GLIBC_2.34 tss_delete F
 GLIBC_2.34 tss_get F
 GLIBC_2.34 tss_set F
+GLIBC_2.35 __epoll_pwait2_time64 F
 GLIBC_2.35 __memcmpeq F
 GLIBC_2.35 _dl_find_object F
+GLIBC_2.35 epoll_pwait2 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 614607fd6b..009dc9da14 100644
--- a/sysdeps/unix/sysv/linux/arm/le/libc.abilist
+++ b/sysdeps/unix/sysv/linux/arm/le/libc.abilist
@@ -488,8 +488,10 @@  GLIBC_2.34 tss_create F
 GLIBC_2.34 tss_delete F
 GLIBC_2.34 tss_get F
 GLIBC_2.34 tss_set F
+GLIBC_2.35 __epoll_pwait2_time64 F
 GLIBC_2.35 __memcmpeq F
 GLIBC_2.35 _dl_find_object F
+GLIBC_2.35 epoll_pwait2 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 2b61543f0d..df8da506cd 100644
--- a/sysdeps/unix/sysv/linux/csky/libc.abilist
+++ b/sysdeps/unix/sysv/linux/csky/libc.abilist
@@ -2647,5 +2647,7 @@  GLIBC_2.34 tss_create F
 GLIBC_2.34 tss_delete F
 GLIBC_2.34 tss_get F
 GLIBC_2.34 tss_set F
+GLIBC_2.35 __epoll_pwait2_time64 F
 GLIBC_2.35 __memcmpeq F
 GLIBC_2.35 _dl_find_object F
+GLIBC_2.35 epoll_pwait2 F
diff --git a/sysdeps/unix/sysv/linux/epoll_pwait2.c b/sysdeps/unix/sysv/linux/epoll_pwait2.c
new file mode 100644
index 0000000000..e38a1b2349
--- /dev/null
+++ b/sysdeps/unix/sysv/linux/epoll_pwait2.c
@@ -0,0 +1,44 @@ 
+/* Implementation of epoll_pwait2 syscall wrapper.
+   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/>.  */
+
+#include <sys/epoll.h>
+#include <sysdep.h>
+
+int
+__epoll_pwait2_time64 (int fd, struct epoll_event *ev, int maxev,
+		       const struct __timespec64 *tmo, const sigset_t *s)
+{
+  /* The syscall only supports 64-bit time_t.  */
+  return SYSCALL_CANCEL (epoll_pwait2, fd, ev, maxev, tmo, s, __NSIG_BYTES);
+}
+#if __TIMESIZE != 64
+libc_hidden_def (__epoll_pwait2_time64)
+
+int
+epoll_pwait2 (int fd, struct epoll_event *ev, int maxev,
+	      const struct timespec *tmo, const sigset_t *s)
+{
+  struct __timespec64 tmo64, *ptmo64 = NULL;
+  if (tmo != NULL)
+    {
+      tmo64 = valid_timespec_to_timespec64 (*tmo);
+      ptmo64 = &tmo64;
+    }
+  return __epoll_pwait2_time64 (fd, ev, maxev, ptmo64, s);
+}
+#endif
diff --git a/sysdeps/unix/sysv/linux/hppa/libc.abilist b/sysdeps/unix/sysv/linux/hppa/libc.abilist
index 6b3cb1adb4..7ea1b017d0 100644
--- a/sysdeps/unix/sysv/linux/hppa/libc.abilist
+++ b/sysdeps/unix/sysv/linux/hppa/libc.abilist
@@ -2596,8 +2596,10 @@  GLIBC_2.34 tss_create F
 GLIBC_2.34 tss_delete F
 GLIBC_2.34 tss_get F
 GLIBC_2.34 tss_set F
+GLIBC_2.35 __epoll_pwait2_time64 F
 GLIBC_2.35 __memcmpeq F
 GLIBC_2.35 _dl_find_object F
+GLIBC_2.35 epoll_pwait2 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 7f608c1b64..99ccf354b3 100644
--- a/sysdeps/unix/sysv/linux/i386/libc.abilist
+++ b/sysdeps/unix/sysv/linux/i386/libc.abilist
@@ -2780,8 +2780,10 @@  GLIBC_2.34 tss_create F
 GLIBC_2.34 tss_delete F
 GLIBC_2.34 tss_get F
 GLIBC_2.34 tss_set F
+GLIBC_2.35 __epoll_pwait2_time64 F
 GLIBC_2.35 __memcmpeq F
 GLIBC_2.35 _dl_find_object F
+GLIBC_2.35 epoll_pwait2 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 865deec43f..201542d1e7 100644
--- a/sysdeps/unix/sysv/linux/ia64/libc.abilist
+++ b/sysdeps/unix/sysv/linux/ia64/libc.abilist
@@ -2549,6 +2549,7 @@  GLIBC_2.34 tss_get F
 GLIBC_2.34 tss_set F
 GLIBC_2.35 __memcmpeq F
 GLIBC_2.35 _dl_find_object F
+GLIBC_2.35 epoll_pwait2 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 a172d74632..32fd72a78d 100644
--- a/sysdeps/unix/sysv/linux/m68k/coldfire/libc.abilist
+++ b/sysdeps/unix/sysv/linux/m68k/coldfire/libc.abilist
@@ -492,8 +492,10 @@  GLIBC_2.34 tss_create F
 GLIBC_2.34 tss_delete F
 GLIBC_2.34 tss_get F
 GLIBC_2.34 tss_set F
+GLIBC_2.35 __epoll_pwait2_time64 F
 GLIBC_2.35 __memcmpeq F
 GLIBC_2.35 _dl_find_object F
+GLIBC_2.35 epoll_pwait2 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 174e9c7739..d26f0ae6c2 100644
--- a/sysdeps/unix/sysv/linux/m68k/m680x0/libc.abilist
+++ b/sysdeps/unix/sysv/linux/m68k/m680x0/libc.abilist
@@ -2723,8 +2723,10 @@  GLIBC_2.34 tss_create F
 GLIBC_2.34 tss_delete F
 GLIBC_2.34 tss_get F
 GLIBC_2.34 tss_set F
+GLIBC_2.35 __epoll_pwait2_time64 F
 GLIBC_2.35 __memcmpeq F
 GLIBC_2.35 _dl_find_object F
+GLIBC_2.35 epoll_pwait2 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 d042be1369..520ca0882d 100644
--- a/sysdeps/unix/sysv/linux/microblaze/be/libc.abilist
+++ b/sysdeps/unix/sysv/linux/microblaze/be/libc.abilist
@@ -2696,5 +2696,7 @@  GLIBC_2.34 tss_create F
 GLIBC_2.34 tss_delete F
 GLIBC_2.34 tss_get F
 GLIBC_2.34 tss_set F
+GLIBC_2.35 __epoll_pwait2_time64 F
 GLIBC_2.35 __memcmpeq F
 GLIBC_2.35 _dl_find_object F
+GLIBC_2.35 epoll_pwait2 F
diff --git a/sysdeps/unix/sysv/linux/microblaze/le/libc.abilist b/sysdeps/unix/sysv/linux/microblaze/le/libc.abilist
index 332da62de2..9162c31396 100644
--- a/sysdeps/unix/sysv/linux/microblaze/le/libc.abilist
+++ b/sysdeps/unix/sysv/linux/microblaze/le/libc.abilist
@@ -2693,5 +2693,7 @@  GLIBC_2.34 tss_create F
 GLIBC_2.34 tss_delete F
 GLIBC_2.34 tss_get F
 GLIBC_2.34 tss_set F
+GLIBC_2.35 __epoll_pwait2_time64 F
 GLIBC_2.35 __memcmpeq F
 GLIBC_2.35 _dl_find_object F
+GLIBC_2.35 epoll_pwait2 F
diff --git a/sysdeps/unix/sysv/linux/mips/mips32/fpu/libc.abilist b/sysdeps/unix/sysv/linux/mips/mips32/fpu/libc.abilist
index 2d6ec0d0e8..656fdbdcaa 100644
--- a/sysdeps/unix/sysv/linux/mips/mips32/fpu/libc.abilist
+++ b/sysdeps/unix/sysv/linux/mips/mips32/fpu/libc.abilist
@@ -2688,8 +2688,10 @@  GLIBC_2.34 tss_create F
 GLIBC_2.34 tss_delete F
 GLIBC_2.34 tss_get F
 GLIBC_2.34 tss_set F
+GLIBC_2.35 __epoll_pwait2_time64 F
 GLIBC_2.35 __memcmpeq F
 GLIBC_2.35 _dl_find_object F
+GLIBC_2.35 epoll_pwait2 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 6c5befa72b..5f0b90d318 100644
--- a/sysdeps/unix/sysv/linux/mips/mips32/nofpu/libc.abilist
+++ b/sysdeps/unix/sysv/linux/mips/mips32/nofpu/libc.abilist
@@ -2686,8 +2686,10 @@  GLIBC_2.34 tss_create F
 GLIBC_2.34 tss_delete F
 GLIBC_2.34 tss_get F
 GLIBC_2.34 tss_set F
+GLIBC_2.35 __epoll_pwait2_time64 F
 GLIBC_2.35 __memcmpeq F
 GLIBC_2.35 _dl_find_object F
+GLIBC_2.35 epoll_pwait2 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 5fb24c97e1..9f4891fc08 100644
--- a/sysdeps/unix/sysv/linux/mips/mips64/n32/libc.abilist
+++ b/sysdeps/unix/sysv/linux/mips/mips64/n32/libc.abilist
@@ -2694,8 +2694,10 @@  GLIBC_2.34 tss_create F
 GLIBC_2.34 tss_delete F
 GLIBC_2.34 tss_get F
 GLIBC_2.34 tss_set F
+GLIBC_2.35 __epoll_pwait2_time64 F
 GLIBC_2.35 __memcmpeq F
 GLIBC_2.35 _dl_find_object F
+GLIBC_2.35 epoll_pwait2 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 f4f29fc15e..f1b0644bc3 100644
--- a/sysdeps/unix/sysv/linux/mips/mips64/n64/libc.abilist
+++ b/sysdeps/unix/sysv/linux/mips/mips64/n64/libc.abilist
@@ -2600,6 +2600,7 @@  GLIBC_2.34 tss_get F
 GLIBC_2.34 tss_set F
 GLIBC_2.35 __memcmpeq F
 GLIBC_2.35 _dl_find_object F
+GLIBC_2.35 epoll_pwait2 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 2e7300cd05..1cf88e38b9 100644
--- a/sysdeps/unix/sysv/linux/nios2/libc.abilist
+++ b/sysdeps/unix/sysv/linux/nios2/libc.abilist
@@ -2735,5 +2735,7 @@  GLIBC_2.34 tss_create F
 GLIBC_2.34 tss_delete F
 GLIBC_2.34 tss_get F
 GLIBC_2.34 tss_set F
+GLIBC_2.35 __epoll_pwait2_time64 F
 GLIBC_2.35 __memcmpeq F
 GLIBC_2.35 _dl_find_object F
+GLIBC_2.35 epoll_pwait2 F
diff --git a/sysdeps/unix/sysv/linux/or1k/libc.abilist b/sysdeps/unix/sysv/linux/or1k/libc.abilist
index eea4e3dc3f..ac2a8284ce 100644
--- a/sysdeps/unix/sysv/linux/or1k/libc.abilist
+++ b/sysdeps/unix/sysv/linux/or1k/libc.abilist
@@ -697,6 +697,7 @@  GLIBC_2.35 epoll_create F
 GLIBC_2.35 epoll_create1 F
 GLIBC_2.35 epoll_ctl F
 GLIBC_2.35 epoll_pwait F
+GLIBC_2.35 epoll_pwait2 F
 GLIBC_2.35 epoll_wait F
 GLIBC_2.35 erand48 F
 GLIBC_2.35 erand48_r F
diff --git a/sysdeps/unix/sysv/linux/powerpc/powerpc32/fpu/libc.abilist b/sysdeps/unix/sysv/linux/powerpc/powerpc32/fpu/libc.abilist
index 129a2f16a7..9692335d10 100644
--- a/sysdeps/unix/sysv/linux/powerpc/powerpc32/fpu/libc.abilist
+++ b/sysdeps/unix/sysv/linux/powerpc/powerpc32/fpu/libc.abilist
@@ -2750,8 +2750,10 @@  GLIBC_2.34 tss_create F
 GLIBC_2.34 tss_delete F
 GLIBC_2.34 tss_get F
 GLIBC_2.34 tss_set F
+GLIBC_2.35 __epoll_pwait2_time64 F
 GLIBC_2.35 __memcmpeq F
 GLIBC_2.35 _dl_find_object F
+GLIBC_2.35 epoll_pwait2 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 7e23226779..7da0ed59f2 100644
--- a/sysdeps/unix/sysv/linux/powerpc/powerpc32/nofpu/libc.abilist
+++ b/sysdeps/unix/sysv/linux/powerpc/powerpc32/nofpu/libc.abilist
@@ -2783,8 +2783,10 @@  GLIBC_2.34 tss_create F
 GLIBC_2.34 tss_delete F
 GLIBC_2.34 tss_get F
 GLIBC_2.34 tss_set F
+GLIBC_2.35 __epoll_pwait2_time64 F
 GLIBC_2.35 __memcmpeq F
 GLIBC_2.35 _dl_find_object F
+GLIBC_2.35 epoll_pwait2 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 6f97392b70..72cf685198 100644
--- a/sysdeps/unix/sysv/linux/powerpc/powerpc64/be/libc.abilist
+++ b/sysdeps/unix/sysv/linux/powerpc/powerpc64/be/libc.abilist
@@ -2508,6 +2508,7 @@  GLIBC_2.34 tss_get F
 GLIBC_2.34 tss_set F
 GLIBC_2.35 __memcmpeq F
 GLIBC_2.35 _dl_find_object F
+GLIBC_2.35 epoll_pwait2 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 29058a041a..ee7f67f4d0 100644
--- a/sysdeps/unix/sysv/linux/powerpc/powerpc64/le/libc.abilist
+++ b/sysdeps/unix/sysv/linux/powerpc/powerpc64/le/libc.abilist
@@ -2810,3 +2810,4 @@  GLIBC_2.34 tss_get F
 GLIBC_2.34 tss_set F
 GLIBC_2.35 __memcmpeq F
 GLIBC_2.35 _dl_find_object F
+GLIBC_2.35 epoll_pwait2 F
diff --git a/sysdeps/unix/sysv/linux/riscv/rv32/libc.abilist b/sysdeps/unix/sysv/linux/riscv/rv32/libc.abilist
index d2924766d2..b8c0854508 100644
--- a/sysdeps/unix/sysv/linux/riscv/rv32/libc.abilist
+++ b/sysdeps/unix/sysv/linux/riscv/rv32/libc.abilist
@@ -2377,3 +2377,4 @@  GLIBC_2.34 tss_get F
 GLIBC_2.34 tss_set F
 GLIBC_2.35 __memcmpeq F
 GLIBC_2.35 _dl_find_object F
+GLIBC_2.35 epoll_pwait2 F
diff --git a/sysdeps/unix/sysv/linux/riscv/rv64/libc.abilist b/sysdeps/unix/sysv/linux/riscv/rv64/libc.abilist
index b770e05da3..90f331fc0b 100644
--- a/sysdeps/unix/sysv/linux/riscv/rv64/libc.abilist
+++ b/sysdeps/unix/sysv/linux/riscv/rv64/libc.abilist
@@ -2577,3 +2577,4 @@  GLIBC_2.34 tss_get F
 GLIBC_2.34 tss_set F
 GLIBC_2.35 __memcmpeq F
 GLIBC_2.35 _dl_find_object F
+GLIBC_2.35 epoll_pwait2 F
diff --git a/sysdeps/unix/sysv/linux/s390/s390-32/libc.abilist b/sysdeps/unix/sysv/linux/s390/s390-32/libc.abilist
index bed3433a2b..ded5e3c0ce 100644
--- a/sysdeps/unix/sysv/linux/s390/s390-32/libc.abilist
+++ b/sysdeps/unix/sysv/linux/s390/s390-32/libc.abilist
@@ -2748,8 +2748,10 @@  GLIBC_2.34 tss_create F
 GLIBC_2.34 tss_delete F
 GLIBC_2.34 tss_get F
 GLIBC_2.34 tss_set F
+GLIBC_2.35 __epoll_pwait2_time64 F
 GLIBC_2.35 __memcmpeq F
 GLIBC_2.35 _dl_find_object F
+GLIBC_2.35 epoll_pwait2 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 4f1a143da5..4b26299254 100644
--- a/sysdeps/unix/sysv/linux/s390/s390-64/libc.abilist
+++ b/sysdeps/unix/sysv/linux/s390/s390-64/libc.abilist
@@ -2545,6 +2545,7 @@  GLIBC_2.34 tss_get F
 GLIBC_2.34 tss_set F
 GLIBC_2.35 __memcmpeq F
 GLIBC_2.35 _dl_find_object F
+GLIBC_2.35 epoll_pwait2 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 92c8dec8ec..8bfd716fd2 100644
--- a/sysdeps/unix/sysv/linux/sh/be/libc.abilist
+++ b/sysdeps/unix/sysv/linux/sh/be/libc.abilist
@@ -2603,8 +2603,10 @@  GLIBC_2.34 tss_create F
 GLIBC_2.34 tss_delete F
 GLIBC_2.34 tss_get F
 GLIBC_2.34 tss_set F
+GLIBC_2.35 __epoll_pwait2_time64 F
 GLIBC_2.35 __memcmpeq F
 GLIBC_2.35 _dl_find_object F
+GLIBC_2.35 epoll_pwait2 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 263da58cb7..47fd204d84 100644
--- a/sysdeps/unix/sysv/linux/sh/le/libc.abilist
+++ b/sysdeps/unix/sysv/linux/sh/le/libc.abilist
@@ -2600,8 +2600,10 @@  GLIBC_2.34 tss_create F
 GLIBC_2.34 tss_delete F
 GLIBC_2.34 tss_get F
 GLIBC_2.34 tss_set F
+GLIBC_2.35 __epoll_pwait2_time64 F
 GLIBC_2.35 __memcmpeq F
 GLIBC_2.35 _dl_find_object F
+GLIBC_2.35 epoll_pwait2 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 0171efe7db..9b82f15109 100644
--- a/sysdeps/unix/sysv/linux/sparc/sparc32/libc.abilist
+++ b/sysdeps/unix/sysv/linux/sparc/sparc32/libc.abilist
@@ -2743,8 +2743,10 @@  GLIBC_2.34 tss_create F
 GLIBC_2.34 tss_delete F
 GLIBC_2.34 tss_get F
 GLIBC_2.34 tss_set F
+GLIBC_2.35 __epoll_pwait2_time64 F
 GLIBC_2.35 __memcmpeq F
 GLIBC_2.35 _dl_find_object F
+GLIBC_2.35 epoll_pwait2 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 7f8d45f362..94caf012a7 100644
--- a/sysdeps/unix/sysv/linux/sparc/sparc64/libc.abilist
+++ b/sysdeps/unix/sysv/linux/sparc/sparc64/libc.abilist
@@ -2572,6 +2572,7 @@  GLIBC_2.34 tss_get F
 GLIBC_2.34 tss_set F
 GLIBC_2.35 __memcmpeq F
 GLIBC_2.35 _dl_find_object F
+GLIBC_2.35 epoll_pwait2 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/epoll.h b/sysdeps/unix/sysv/linux/sys/epoll.h
index 0d013c3e20..b95ca68749 100644
--- a/sysdeps/unix/sysv/linux/sys/epoll.h
+++ b/sysdeps/unix/sysv/linux/sys/epoll.h
@@ -22,6 +22,7 @@ 
 #include <sys/types.h>
 
 #include <bits/types/sigset_t.h>
+#include <bits/types/struct_timespec.h>
 
 /* Get the platform-dependent flags.  */
 #include <bits/epoll.h>
@@ -133,6 +134,26 @@  extern int epoll_pwait (int __epfd, struct epoll_event *__events,
 			int __maxevents, int __timeout,
 			const __sigset_t *__ss);
 
+/* Same as epoll_pwait, but the timeout as a timespec.
+
+   This function is a cancellation point and therefore not marked with
+   __THROW.  */
+#ifndef __USE_TIME_BITS64
+extern int epoll_pwait2 (int __epfd, struct epoll_event *__events,
+			 int __maxevents, const struct timespec *__timeout,
+			 const __sigset_t *__ss);
+#else
+# ifdef __REDIRECT
+extern int __REDIRECT (epoll_pwait2, (int __epfd, struct epoll_event *__ev,
+				      int __maxevs,
+				      const struct timespec *__timeout,
+				      const __sigset_t *__ss),
+		       __epoll_pwait2_time64);
+# else
+#  define epoll_pwait2 __epoll_pwait2_time64
+# endif
+#endif
+
 __END_DECLS
 
 #endif /* sys/epoll.h */
diff --git a/sysdeps/unix/sysv/linux/tst-epoll-time64.c b/sysdeps/unix/sysv/linux/tst-epoll-time64.c
new file mode 100644
index 0000000000..2e0236792e
--- /dev/null
+++ b/sysdeps/unix/sysv/linux/tst-epoll-time64.c
@@ -0,0 +1 @@ 
+#include "tst-epoll.c"
diff --git a/sysdeps/unix/sysv/linux/tst-epoll.c b/sysdeps/unix/sysv/linux/tst-epoll.c
new file mode 100644
index 0000000000..e3fe642da8
--- /dev/null
+++ b/sysdeps/unix/sysv/linux/tst-epoll.c
@@ -0,0 +1,217 @@ 
+/* Basic tests for Linux epoll_* wrappers.
+   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/>.  */
+
+#include <errno.h>
+#include <intprops.h>
+#include <support/check.h>
+#include <support/support.h>
+#include <support/xsignal.h>
+#include <support/xunistd.h>
+#include <support/xtime.h>
+#include <stdlib.h>
+#include <sys/epoll.h>
+
+/* The test focus on checking if the timeout argument is correctly handled
+   by glibc wrappers.  */
+
+static sig_atomic_t handler_called;
+
+static void
+handler (int sig)
+{
+  handler_called = 1;
+}
+
+typedef int (*epoll_wait_check_t) (int, struct epoll_event *, int,
+				   int, const sigset_t *);
+
+static void
+test_epoll_basic (epoll_wait_check_t epoll_wait_check)
+{
+  {
+    sigset_t ss_usr1;
+    sigemptyset (&ss_usr1);
+    sigaddset (&ss_usr1, SIGUSR1);
+    TEST_COMPARE (sigprocmask (SIG_BLOCK, &ss_usr1, NULL), 0);
+  }
+
+  int fds[2][2];
+  xpipe (fds[0]);
+  xpipe (fds[1]);
+
+  sigset_t ss;
+  TEST_COMPARE (sigprocmask (SIG_SETMASK, NULL, &ss), 0);
+  sigdelset (&ss, SIGUSR1);
+
+  int efd = epoll_create1 (0);
+  TEST_VERIFY_EXIT (efd != -1);
+
+  struct epoll_event event;
+
+  event.data.fd = fds[1][0];
+  event.events = EPOLLIN | EPOLLET;
+  TEST_COMPARE (epoll_ctl (efd, EPOLL_CTL_ADD, fds[1][0], &event), 0);
+
+  pid_t parent = getpid ();
+  pid_t p = xfork ();
+  if (p == 0)
+    {
+      xclose (fds[0][1]);
+      xclose (fds[1][0]);
+
+      event.data.fd = fds[0][0];
+      event.events = EPOLLIN | EPOLLET;
+      TEST_COMPARE (epoll_ctl (efd, EPOLL_CTL_ADD, fds[0][0], &event), 0);
+
+      int e;
+      do
+	{
+	  if (getppid () != parent)
+	    FAIL_EXIT1 ("getppid()=%d != parent=%d", getppid(), parent);
+
+	  errno = 0;
+	  e = epoll_wait_check (efd, &event, 1, 500, &ss);
+	}
+      while (e == 0);
+
+      TEST_COMPARE (e, -1);
+      TEST_COMPARE (errno, EINTR);
+
+      TEMP_FAILURE_RETRY (write (fds[1][1], "foo", 3));
+
+      exit (0);
+    }
+
+  xclose (fds[0][0]);
+  xclose (fds[1][1]);
+
+  /* Wait some time so child is blocked on the syscall.  */
+  nanosleep (&(struct timespec) {0, 10000000}, NULL);
+  TEST_COMPARE (kill (p, SIGUSR1), 0);
+
+  int e = epoll_wait_check (efd, &event, 1, 500000000, &ss);
+  TEST_COMPARE (e, 1);
+  TEST_VERIFY (event.events & EPOLLIN);
+
+  xclose (fds[0][1]);
+  xclose (fds[1][0]);
+  xclose (efd);
+}
+
+
+static void
+test_epoll_large_timeout (epoll_wait_check_t epoll_wait_check)
+{
+  timer_t t = support_create_timer (0, 100000000, true, NULL);
+
+  int fds[2];
+  xpipe (fds);
+
+  fd_set rfds;
+  FD_ZERO (&rfds);
+  FD_SET (fds[0], &rfds);
+
+  sigset_t ss;
+  TEST_COMPARE (sigprocmask (SIG_SETMASK, NULL, &ss), 0);
+  sigdelset (&ss, SIGALRM);
+
+  int efd = epoll_create1 (0);
+  TEST_VERIFY_EXIT (efd != -1);
+
+  struct epoll_event event;
+  event.data.fd = fds[0];
+  event.events = EPOLLIN | EPOLLET;
+  TEST_COMPARE (epoll_ctl (efd, EPOLL_CTL_ADD, fds[0], &event), 0);
+
+  int tmo = TYPE_MAXIMUM (int);
+#if 0
+  TEST_COMPARE (epoll_pwait (efd, &event, 1, tmo, &ss), -1);
+#endif
+  TEST_COMPARE (epoll_wait_check (efd, &event, 1, tmo, &ss), -1);
+  TEST_VERIFY (errno == EINTR || errno == EOVERFLOW);
+
+  TEST_COMPARE (epoll_wait_check (efd, &event, 1, -1, &ss), -1);
+  TEST_VERIFY (errno == EINTR || errno == EOVERFLOW);
+
+  support_delete_timer (t);
+
+  xclose (fds[0]);
+  xclose (fds[1]);
+  xclose (efd);
+}
+
+
+static int
+epoll_wait_check (int epfd, struct epoll_event *ev, int maxev, int tmo,
+		  const sigset_t *ss)
+{
+  sigset_t orig;
+  TEST_COMPARE (sigprocmask (SIG_SETMASK, ss, &orig), 0);
+  int r = epoll_wait (epfd, ev, maxev, tmo);
+  TEST_COMPARE (sigprocmask (SIG_SETMASK, &orig, NULL), 0);
+  return r;
+}
+
+static int
+epoll_pwait_check (int epfd, struct epoll_event *ev, int maxev, int tmo,
+		   const sigset_t *ss)
+{
+  return epoll_pwait (epfd, ev, maxev, tmo, ss);
+}
+
+static int
+epoll_pwait2_check (int epfd, struct epoll_event *ev, int maxev, int tmo,
+		    const sigset_t *ss)
+{
+  time_t s = tmo == -1 ? TYPE_MAXIMUM (time_t) : tmo / 1000;
+  long int ns = tmo == -1 ? 0 : (tmo % 1000) * 1000000;
+  return epoll_pwait2 (epfd, ev, maxev, &(struct timespec) { s, ns }, ss);
+}
+
+static int
+do_test (void)
+{
+  {
+    struct sigaction sa;
+    sa.sa_handler = handler;
+    sa.sa_flags = 0;
+    sigemptyset (&sa.sa_mask);
+    xsigaction (SIGUSR1, &sa, NULL);
+
+    sa.sa_handler = SIG_IGN;
+    xsigaction (SIGCHLD, &sa, NULL);
+  }
+
+  int r = epoll_pwait2 (-1, NULL, 0, NULL, NULL);
+  TEST_COMPARE (r, -1);
+  bool pwait2_supported = errno != ENOSYS;
+
+  test_epoll_basic (epoll_wait_check);
+  test_epoll_basic (epoll_pwait_check);
+  if (pwait2_supported)
+    test_epoll_basic (epoll_pwait2_check);
+
+  test_epoll_large_timeout (epoll_wait_check);
+  test_epoll_large_timeout (epoll_pwait_check);
+  if (pwait2_supported)
+    test_epoll_large_timeout (epoll_pwait2_check);
+
+  return 0;
+}
+
+#include <support/test-driver.c>
diff --git a/sysdeps/unix/sysv/linux/x86_64/64/libc.abilist b/sysdeps/unix/sysv/linux/x86_64/64/libc.abilist
index c2f1a8ecc6..140e9e8c1c 100644
--- a/sysdeps/unix/sysv/linux/x86_64/64/libc.abilist
+++ b/sysdeps/unix/sysv/linux/x86_64/64/libc.abilist
@@ -2523,6 +2523,7 @@  GLIBC_2.34 tss_get F
 GLIBC_2.34 tss_set F
 GLIBC_2.35 __memcmpeq F
 GLIBC_2.35 _dl_find_object F
+GLIBC_2.35 epoll_pwait2 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 8b43acf100..04d13ce27e 100644
--- a/sysdeps/unix/sysv/linux/x86_64/x32/libc.abilist
+++ b/sysdeps/unix/sysv/linux/x86_64/x32/libc.abilist
@@ -2629,3 +2629,4 @@  GLIBC_2.34 tss_get F
 GLIBC_2.34 tss_set F
 GLIBC_2.35 __memcmpeq F
 GLIBC_2.35 _dl_find_object F
+GLIBC_2.35 epoll_pwait2 F