nptl: Implement raise in terms of pthread_kill

Now that pthread_kill is provided by libc.so it is possible to
implement the generic POSIX implementation as
'pthread_kill(pthread_self(), sig)'.

For Linux implementation, pthread_kill read the targeting TID from
the TCB.  For raise, this it not possible because it would make raise
fail when issue after vfork (where creates the resulting process
has a different TID from the parent, but its TCB is not updated as
for pthread_create).  To make raise use pthread_kill, it is make
usable from vfork by getting the target thread id through gettid
syscall.

Checked on x86_64-linux-gnu and aarch64-linux-gnu.

1 files changed, 9 insertions, 2 deletions

diff --git a/sysdeps/posix/raise.c b/sysdeps/posix/raise.c
index 9fdb4d538b..4806c0cc63 100644
--- a/sysdeps/posix/raise.c
+++ b/sysdeps/posix/raise.c
@@ -16,13 +16,20 @@
    <https://www.gnu.org/licenses/>.  */
 
 #include <signal.h>
-#include <unistd.h>
+#include <errno.h>
+#include <pthread.h>
 
 /* Raise the signal SIG.  */
 int
 raise (int sig)
 {
-  return __kill (__getpid (), sig);
+  int ret = __pthread_kill (__pthread_self (), sig);
+  if (ret != 0)
+    {
+      __set_errno (ret);
+      ret = -1;
+    }
+  return ret;
 }
 libc_hidden_def (raise)
 weak_alias (raise, gsignal)