nptl: Replace pthread_sigqueue implementation with Linux one

Reviewed-by: Adhemerval Zanella  <adhemerval.zanella@linaro.org>

1 files changed, 38 insertions, 4 deletions

diff --git a/nptl/pthread_sigqueue.c b/nptl/pthread_sigqueue.c
index 7d60e2b98d..64bacfe41b 100644
--- a/nptl/pthread_sigqueue.c
+++ b/nptl/pthread_sigqueue.c
@@ -1,6 +1,6 @@
-/* Queue a signal (with value) for a specific pthread.  Stub version.
-   Copyright (C) 2014-2021 Free Software Foundation, Inc.
+/* Copyright (C) 2009-2021 Free Software Foundation, Inc.
    This file is part of the GNU C Library.
+   Contributed by Ulrich Drepper <drepper@redhat.com>, 2009.
 
    The GNU C Library is free software; you can redistribute it and/or
    modify it under the terms of the GNU Lesser General Public
@@ -18,12 +18,17 @@
 
 #include <errno.h>
 #include <signal.h>
+#include <string.h>
+#include <unistd.h>
 #include <pthreadP.h>
+#include <tls.h>
+#include <sysdep.h>
 
 
 int
 pthread_sigqueue (pthread_t threadid, int signo, const union sigval value)
 {
+#ifdef __NR_rt_tgsigqueueinfo
   struct pthread *pd = (struct pthread *) threadid;
 
   /* Make sure the descriptor is valid.  */
@@ -31,7 +36,36 @@ pthread_sigqueue (pthread_t threadid, int signo, const union sigval value)
     /* Not a valid thread handle.  */
     return ESRCH;
 
+  /* Force load of pd->tid into local variable or register.  Otherwise
+     if a thread exits between ESRCH test and tgkill, we might return
+     EINVAL, because pd->tid would be cleared by the kernel.  */
+  pid_t tid = atomic_forced_read (pd->tid);
+  if (__glibc_unlikely (tid <= 0))
+    /* Not a valid thread handle.  */
+    return ESRCH;
+
+  /* Disallow sending the signal we use for cancellation, timers,
+     for the setxid implementation.  */
+  if (signo == SIGCANCEL || signo == SIGTIMER || signo == SIGSETXID)
+    return EINVAL;
+
+  pid_t pid = getpid ();
+
+  /* Set up the siginfo_t structure.  */
+  siginfo_t info;
+  memset (&info, '\0', sizeof (siginfo_t));
+  info.si_signo = signo;
+  info.si_code = SI_QUEUE;
+  info.si_pid = pid;
+  info.si_uid = getuid ();
+  info.si_value = value;
+
+  /* We have a special syscall to do the work.  */
+  int val = INTERNAL_SYSCALL_CALL (rt_tgsigqueueinfo, pid, tid, signo,
+				   &info);
+  return (INTERNAL_SYSCALL_ERROR_P (val)
+	  ? INTERNAL_SYSCALL_ERRNO (val) : 0);
+#else
   return ENOSYS;
+#endif
 }
-
-stub_warning (pthread_sigqueue)