Simplify Linux sig{timed}wait{info} implementations

This patch simplifies sig{timed}wait{info} by:

  - Assuming __NR_rt_sigtimedwait existence on all architectures due minimum
    kernel version requirement (it pre-dates Linux git inclusion for Linux
    2.6.12).

  - Call __sigtimedwait on both sigwait and sigwaitinfo.

  - Now that sigwait is based on an internal sigtimedwait call and it is
    present of both libc.so and libpthread.so we need to add an external
    private definition of __sigtimedwait for libpthread.so call.

Checked on x86_64-linux-gnu.

	* sysdeps/unix/sysv/linux/Versions (libc) [GLIBC_PRIVATE]: Add
	__sigtimedwait.
	* sysdeps/unix/sysv/linux/sigtimedwait.c: Simplify includes and
	assume __NR_rt_sigtimedwait.
	* sysdeps/unix/sysv/linux/sigwait.c (__sigwait): Call __sigtimedwait
	and add LIBC_CANCEL_HANDLED for cancellation marking.
	* sysdeps/unix/sysv/linux/sigwaitinfo.c (__sigwaitinfo): Likewise.

Signed-off-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
Reviewed-by: Zack Weinberg <zackw@panix.com>

1 files changed, 4 insertions, 37 deletions

diff --git a/sysdeps/unix/sysv/linux/sigwaitinfo.c b/sysdeps/unix/sysv/linux/sigwaitinfo.c
index 0062d3ea86..75ddd52283 100644
--- a/sysdeps/unix/sysv/linux/sigwaitinfo.c
+++ b/sysdeps/unix/sysv/linux/sigwaitinfo.c
@@ -15,52 +15,19 @@
    License along with the GNU C Library; if not, see
    <http://www.gnu.org/licenses/>.  */
 
-#include <errno.h>
 #include <signal.h>
-#define __need_NULL
-#include <stddef.h>
-#include <string.h>
-
-#include <nptl/pthreadP.h>
 #include <sysdep-cancel.h>
-#include <sys/syscall.h>
-
-#ifdef __NR_rt_sigtimedwait
 
 /* Return any pending signal or wait for one for the given time.  */
 int
 __sigwaitinfo (const sigset_t *set, siginfo_t *info)
 {
-  sigset_t tmpset;
-  if (set != NULL
-      && (__builtin_expect (__sigismember (set, SIGCANCEL), 0)
-	  || __builtin_expect (__sigismember (set, SIGSETXID), 0)))
-    {
-      /* Create a temporary mask without the bit for SIGCANCEL set.  */
-      // We are not copying more than we have to.
-      memcpy (&tmpset, set, _NSIG / 8);
-      __sigdelset (&tmpset, SIGCANCEL);
-      __sigdelset (&tmpset, SIGSETXID);
-      set = &tmpset;
-    }
-
-  /* XXX The size argument hopefully will have to be changed to the
-     real size of the user-level sigset_t.  */
-  int result = SYSCALL_CANCEL (rt_sigtimedwait, set, info, NULL, _NSIG / 8);
-
-  /* The kernel generates a SI_TKILL code in si_code in case tkill is
-     used.  tkill is transparently used in raise().  Since having
-     SI_TKILL as a code is useful in general we fold the results
-     here.  */
-  if (result != -1 && info != NULL && info->si_code == SI_TKILL)
-    info->si_code = SI_USER;
-
-  return result;
+  return __sigtimedwait (set, info, 0);
 }
 
 libc_hidden_def (__sigwaitinfo)
 weak_alias (__sigwaitinfo, sigwaitinfo)
-#else
-# include <signal/sigwaitinfo.c>
-#endif
 strong_alias (__sigwaitinfo, __libc_sigwaitinfo)
+
+/* __sigtimedwait handles cancellation.  */
+LIBC_CANCEL_HANDLED ();