X-Git-Url: http://nsz.repo.hu/git/?a=blobdiff_plain;f=src%2Ftime%2Fclock_gettime.c;h=241288042d64c36ce13f4506a5d0f5a8695a7ac1;hb=cfa0a54c082d41db6446638eed1d57f163434092;hp=9fef54a497b980e1ea121b584e1ed0c6fe83e044;hpb=e91c375fd027a485bd7415afbaf059d429e11e11;p=musl

diff --git a/src/time/clock_gettime.c b/src/time/clock_gettime.c
index 9fef54a4..24128804 100644
--- a/src/time/clock_gettime.c
+++ b/src/time/clock_gettime.c
@@ -3,27 +3,56 @@
 #include <stdint.h>
 #include "syscall.h"
 #include "libc.h"
+#include "atomic.h"
 
-int __vdso_clock_gettime(clockid_t, struct timespec *) __attribute__((weak));
-static int (*cgt)(clockid_t, struct timespec *) = __vdso_clock_gettime;
+#ifdef VDSO_CGT_SYM
+
+void *__vdsosym(const char *, const char *);
+
+static void *volatile vdso_func;
+
+static int cgt_init(clockid_t clk, struct timespec *ts)
+{
+	void *p = __vdsosym(VDSO_CGT_VER, VDSO_CGT_SYM);
+	int (*f)(clockid_t, struct timespec *) =
+		(int (*)(clockid_t, struct timespec *))p;
+	a_cas_p(&vdso_func, (void *)cgt_init, p);
+	return f ? f(clk, ts) : -ENOSYS;
+}
+
+static void *volatile vdso_func = (void *)cgt_init;
+
+#endif
 
 int __clock_gettime(clockid_t clk, struct timespec *ts)
 {
 	int r;
-	if (cgt) return cgt(clk, ts);
+
+#ifdef VDSO_CGT_SYM
+	int (*f)(clockid_t, struct timespec *) =
+		(int (*)(clockid_t, struct timespec *))vdso_func;
+	if (f) {
+		r = f(clk, ts);
+		if (!r) return r;
+		if (r == -EINVAL) return __syscall_ret(r);
+		/* Fall through on errors other than EINVAL. Some buggy
+		 * vdso implementations return ENOSYS for clocks they
+		 * can't handle, rather than making the syscall. This
+		 * also handles the case where cgt_init fails to find
+		 * a vdso function to use. */
+	}
+#endif
+
 	r = __syscall(SYS_clock_gettime, clk, ts);
-	if (!r) return r;
 	if (r == -ENOSYS) {
-		cgt = 0;
 		if (clk == CLOCK_REALTIME) {
-			__syscall(SYS_gettimeofday, clk, ts, 0);
+			__syscall(SYS_gettimeofday, ts, 0);
 			ts->tv_nsec = (int)ts->tv_nsec * 1000;
 			return 0;
 		}
 		r = -EINVAL;
 	}
-	errno = -r;
-	return -1;
+	return __syscall_ret(r);
 }
 
 weak_alias(__clock_gettime, clock_gettime);