rework cancellation for sigwait, sigtimedwait and sigwaitinfo

sigtimedwait:
- provide __sigtimedwait_nocancel
- use __SYSCALL_SIGSET_T_SIZE instead of _NSIG / 8
- do not provide __sigtimedwait
- guard a section to avoid failure on archs if SI_TKILL/SI_USER are not defined
sigwaitinfo:
- simply use sigtimedwait since that handles cancellation already
sigwait:
- use non-cancellable functions (sigtimedwait, sigsuspend)
- get rid of code already done in __sigtimedwait_nocancel

Signed-off-by: Peter S. Mazinger <ps.m@gmx.net>
Signed-off-by: Bernhard Reutner-Fischer <rep.dot.nop@gmail.com>

2 files changed, 36 insertions, 117 deletions

diff --git a/libc/sysdeps/linux/common/__rt_sigtimedwait.c b/libc/sysdeps/linux/common/__rt_sigtimedwait.c
index 168e38071..962ccb04b 100644
--- a/libc/sysdeps/linux/common/__rt_sigtimedwait.c
+++ b/libc/sysdeps/linux/common/__rt_sigtimedwait.c
@@ -9,41 +9,46 @@
  */
 
 #include <sys/syscall.h>
-#include <signal.h>
-#include <string.h>
 
 #ifdef __NR_rt_sigtimedwait
+# include <signal.h>
+# include <cancel.h>
+# ifdef SIGCANCEL /* defined only in NPTL's pthreadP.h */
+#  define __need_NULL
+#  include <stddef.h>
+#  include <string.h>
+# endif
 
-# ifdef __UCLIBC_HAS_THREADS_NATIVE__
-#  include <sysdep-cancel.h>
-
-static int do_sigtimedwait(const sigset_t *set, siginfo_t *info,
-						   const struct timespec *timeout)
+int __NC(sigtimedwait)(const sigset_t *set, siginfo_t *info,
+		       const struct timespec *timeout)
 {
-#  ifdef SIGCANCEL
+# ifdef SIGCANCEL
 	sigset_t tmpset;
 
 	if (set != NULL && (__builtin_expect (__sigismember (set, SIGCANCEL), 0)
-#   ifdef SIGSETXID
+#  ifdef SIGSETXID
 		|| __builtin_expect (__sigismember (set, SIGSETXID), 0)
-#   endif
+#  endif
 		))
 	{
 		/* 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);
-#   ifdef SIGSETXID
+#  ifdef SIGSETXID
 		__sigdelset (&tmpset, SIGSETXID);
-#   endif
+#  endif
 		set = &tmpset;
 	}
-#  endif
+# endif
 
+/* if this is enabled, enable the disabled section in sigwait.c */
+# if defined SI_TKILL && defined SI_USER
 	/* XXX The size argument hopefully will have to be changed to the
 	   real size of the user-level sigset_t.  */
-	int result = INLINE_SYSCALL (rt_sigtimedwait, 4, set, info,
-								 timeout, _NSIG / 8);
+	/* on uClibc we use the kernel sigset_t size */
+	int result = INLINE_SYSCALL(rt_sigtimedwait, 4, set, info,
+				    timeout, __SYSCALL_SIGSET_T_SIZE);
 
 	/* The kernel generates a SI_TKILL code in si_code in case tkill is
 	   used.  tkill is transparently used in raise().  Since having
@@ -53,38 +58,14 @@ static int do_sigtimedwait(const sigset_t *set, siginfo_t *info,
 		info->si_code = SI_USER;
 
 	return result;
-}
-
-/* Return any pending signal or wait for one for the given time.  */
-int __sigtimedwait(const sigset_t *set, siginfo_t *info,
-		   const struct timespec *timeout)
-{
-	if(SINGLE_THREAD_P)
-		return do_sigtimedwait(set, info, timeout);
-
-	int oldtype = LIBC_CANCEL_ASYNC();
-
-	/* XXX The size argument hopefully will have to be changed to the
-	   real size of the user-level sigset_t.  */
-	int result = do_sigtimedwait(set, info, timeout);
-
-	LIBC_CANCEL_RESET(oldtype);
-
-	return result;
-}
 # else
-#  define __need_NULL
-#  include <stddef.h>
-#  define __NR___rt_sigtimedwait __NR_rt_sigtimedwait
-static _syscall4(int, __rt_sigtimedwait, const sigset_t *, set,
-		 siginfo_t *, info, const struct timespec *, timeout,
-		 size_t, setsize);
-
-int __sigtimedwait(const sigset_t * set, siginfo_t * info,
-		   const struct timespec *timeout)
-{
-	return __rt_sigtimedwait(set, info, timeout, _NSIG / 8);
+	/* on uClibc we use the kernel sigset_t size */
+	return INLINE_SYSCALL(rt_sigtimedwait, 4, set, info,
+			      timeout, __SYSCALL_SIGSET_T_SIZE);
+# endif
 }
-# endif /* !__UCLIBC_HAS_THREADS_NATIVE__ */
-weak_alias(__sigtimedwait,sigtimedwait)
+CANCELLABLE_SYSCALL(int, sigtimedwait,
+		    (const sigset_t *set, siginfo_t *info, const struct timespec *timeout),
+		    (set, info, timeout))
+lt_libc_hidden(sigtimedwait)
 #endif
diff --git a/libc/sysdeps/linux/common/__rt_sigwaitinfo.c b/libc/sysdeps/linux/common/__rt_sigwaitinfo.c
index 74db6d6f9..ad1a7a890 100644
--- a/libc/sysdeps/linux/common/__rt_sigwaitinfo.c
+++ b/libc/sysdeps/linux/common/__rt_sigwaitinfo.c
@@ -9,79 +9,17 @@
  */
 
 #include <sys/syscall.h>
-#include <signal.h>
-#include <string.h>
 
 #ifdef __NR_rt_sigtimedwait
+# define __need_NULL
+# include <stddef.h>
+# include <signal.h>
+# include <cancel.h>
 
-# ifdef __UCLIBC_HAS_THREADS_NATIVE__
-#  include <sysdep-cancel.h>
-
-static int do_sigwaitinfo(const sigset_t *set, siginfo_t *info)
-{
-#  ifdef SIGCANCEL
-	sigset_t tmpset;
-
-	if (set != NULL && (__builtin_expect (__sigismember (set, SIGCANCEL), 0)
-#   ifdef SIGSETXID
-		|| __builtin_expect (__sigismember (set, SIGSETXID), 0)
-#   endif
-		))
-	{
-		/* 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);
-#   ifdef SIGSETXID
-		__sigdelset (&tmpset, SIGSETXID);
-#   endif
-		set = &tmpset;
-	}
-#  endif
-
-	/* XXX The size argument hopefully will have to be changed to the
-	   real size of the user-level sigset_t.  */
-	int result = INLINE_SYSCALL (rt_sigtimedwait, 4, 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 any pending signal or wait for one for the given time.  */
-int __sigwaitinfo(const sigset_t *set, siginfo_t *info)
-{
-	if(SINGLE_THREAD_P)
-		return do_sigwaitinfo(set, info);
-
-	int oldtype = LIBC_CANCEL_ASYNC();
-
-	/* XXX The size argument hopefully will have to be changed to the
-	   real size of the user-level sigset_t.  */
-	int result = do_sigwaitinfo(set, info);
-
-	LIBC_CANCEL_RESET(oldtype);
-
-	return result;
-}
-# else
-#  define __need_NULL
-#  include <stddef.h>
-#  define __NR___rt_sigwaitinfo __NR_rt_sigtimedwait
-static _syscall4(int, __rt_sigwaitinfo, const sigset_t *, set,
-		 siginfo_t *, info, const struct timespec *, timeout,
-		 size_t, setsize);
-
-int __sigwaitinfo(const sigset_t * set, siginfo_t * info)
+int sigwaitinfo(const sigset_t *set, siginfo_t *info)
 {
-	return __rt_sigwaitinfo(set, info, NULL, _NSIG / 8);
+	return sigtimedwait(set, info, NULL);
 }
-# endif
-weak_alias (__sigwaitinfo, sigwaitinfo)
+/* cancellation handled by sigtimedwait, noop on uClibc */
+LIBC_CANCEL_HANDLED();
 #endif