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, 5 insertions, 0 deletions

diff --git a/include/pthread.h b/include/pthread.h
index a3e1cf51b0..1158919247 100644
--- a/include/pthread.h
+++ b/include/pthread.h
@@ -16,4 +16,9 @@ extern int __pthread_barrier_wait (pthread_barrier_t *__barrier)
 
 /* This function is called to initialize the pthread library.  */
 extern void __pthread_initialize (void) __attribute__ ((weak));
+
+extern int __pthread_kill (pthread_t threadid, int signo);
+
+extern pthread_t __pthread_self (void);
+
 #endif