X-Git-Url: http://nsz.repo.hu/git/?a=blobdiff_plain;f=src%2Fthread%2F__timedwait.c;h=666093be98516a1c84b2997f075a8dbfcb797b2c;hb=377218cb963aa20c6eb91781b0c79ad606631e6f;hp=229db31302451939c2fab4401fd9bcdb2a77128c;hpb=13d1afa46f8098df290008c681816c9eb89ffbdb;p=musl

diff --git a/src/thread/__timedwait.c b/src/thread/__timedwait.c
index 229db313..666093be 100644
--- a/src/thread/__timedwait.c
+++ b/src/thread/__timedwait.c
@@ -5,6 +5,30 @@
 #include "syscall.h"
 #include "pthread_impl.h"
 
+#define IS32BIT(x) !((x)+0x80000000ULL>>32)
+#define CLAMP(x) (int)(IS32BIT(x) ? (x) : 0x7fffffffU+((0ULL+(x))>>63))
+
+static int __futex4_cp(volatile void *addr, int op, int val, const struct timespec *to)
+{
+	int r;
+#ifdef SYS_futex_time64
+	time_t s = to ? to->tv_sec : 0;
+	long ns = to ? to->tv_nsec : 0;
+	r = -ENOSYS;
+	if (SYS_futex == SYS_futex_time64 || !IS32BIT(s))
+		r = __syscall_cp(SYS_futex_time64, addr, op, val,
+			to ? ((long long[]){s, ns}) : 0);
+	if (SYS_futex == SYS_futex_time64 || r!=-ENOSYS) return r;
+	to = to ? (void *)(long[]){CLAMP(s), ns} : 0;
+#endif
+	r = __syscall_cp(SYS_futex, addr, op, val, to);
+	if (r != -ENOSYS) return r;
+	return __syscall_cp(SYS_futex, addr, op & ~FUTEX_PRIVATE, val, to);
+}
+
+static volatile int dummy = 0;
+weak_alias(dummy, __eintr_valid_flag);
+
 int __timedwait_cp(volatile int *addr, int val,
 	clockid_t clk, const struct timespec *at, int priv)
 {
@@ -25,9 +49,13 @@ int __timedwait_cp(volatile int *addr, int val,
 		top = &to;
 	}
 
-	r = -__syscall_cp(SYS_futex, addr, FUTEX_WAIT|priv, val, top);
-	if (r == ENOSYS) r = -__syscall_cp(SYS_futex, addr, FUTEX_WAIT, val, top);
+	r = -__futex4_cp(addr, FUTEX_WAIT|priv, val, top);
 	if (r != EINTR && r != ETIMEDOUT && r != ECANCELED) r = 0;
+	/* Mitigate bug in old kernels wrongly reporting EINTR for non-
+	 * interrupting (SA_RESTART) signal handlers. This is only practical
+	 * when NO interrupting signal handlers have been installed, and
+	 * works by sigaction tracking whether that's the case. */
+	if (r == EINTR && !__eintr_valid_flag) r = 0;
 
 	return r;
 }