X-Git-Url: http://nsz.repo.hu/git/?a=blobdiff_plain;f=src%2Ftime%2Fclock_gettime.c;h=3e1d0975b1226548375a8403c2fa4161e1021951;hb=8274aaaaa1948c50c661aa32e21b3db27a5c0eab;hp=1572de0ef0029eb94b53a9928cd0a9fc57684d6a;hpb=56fbaa3bbe73f12af2bfbbcf2adb196e6f9fe264;p=musl

diff --git a/src/time/clock_gettime.c b/src/time/clock_gettime.c
index 1572de0e..3e1d0975 100644
--- a/src/time/clock_gettime.c
+++ b/src/time/clock_gettime.c
@@ -2,39 +2,105 @@
 #include <errno.h>
 #include <stdint.h>
 #include "syscall.h"
-#include "libc.h"
 #include "atomic.h"
 
-static int sc_clock_gettime(clockid_t clk, struct timespec *ts)
+#ifdef VDSO_CGT_SYM
+
+static void *volatile vdso_func;
+
+#ifdef VDSO_CGT32_SYM
+static void *volatile vdso_func_32;
+static int cgt_time32_wrap(clockid_t clk, struct timespec *ts)
 {
-	int r = __syscall(SYS_clock_gettime, clk, ts);
-	if (!r) return r;
-	if (r == -ENOSYS) {
-		if (clk == CLOCK_REALTIME) {
-			__syscall(SYS_gettimeofday, ts, 0);
-			ts->tv_nsec = (int)ts->tv_nsec * 1000;
-			return 0;
+	long ts32[2];
+	int (*f)(clockid_t, long[2]) =
+		(int (*)(clockid_t, long[2]))vdso_func_32;
+	int r = f(clk, ts32);
+	if (!r) {
+		/* Fallback to syscalls if time32 overflowed. Maybe
+		 * we lucked out and somehow migrated to a kernel with
+		 * time64 syscalls available. */
+		if (ts32[0] < 0) {
+			a_cas_p(&vdso_func, (void *)cgt_time32_wrap, 0);
+			return -ENOSYS;
+		}
+		ts->tv_sec = ts32[0];
+		ts->tv_nsec = ts32[1];
+	}
+	return r;
+}
+#endif
+
+static int cgt_init(clockid_t clk, struct timespec *ts)
+{
+	void *p = __vdsosym(VDSO_CGT_VER, VDSO_CGT_SYM);
+#ifdef VDSO_CGT32_SYM
+	if (!p) {
+		void *q = __vdsosym(VDSO_CGT32_VER, VDSO_CGT32_SYM);
+		if (q) {
+			a_cas_p(&vdso_func_32, 0, q);
+			p = cgt_time32_wrap;
 		}
-		r = -EINVAL;
 	}
-	errno = -r;
-	return -1;
+#endif
+	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;
 }
 
-void *__vdsosym(const char *, const char *);
+static void *volatile vdso_func = (void *)cgt_init;
+
+#endif
 
 int __clock_gettime(clockid_t clk, struct timespec *ts)
 {
+	int r;
+
 #ifdef VDSO_CGT_SYM
-	static int (*volatile cgt)(clockid_t, struct timespec *);
-	if (!cgt) {
-		void *f = __vdsosym(VDSO_CGT_VER, VDSO_CGT_SYM);
-		if (!f) f = (void *)sc_clock_gettime;
-		a_cas_p(&cgt, 0, f);
+	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
+
+#ifdef SYS_clock_gettime64
+	r = -ENOSYS;
+	if (sizeof(time_t) > 4)
+		r = __syscall(SYS_clock_gettime64, clk, ts);
+	if (SYS_clock_gettime == SYS_clock_gettime64 || r!=-ENOSYS)
+		return __syscall_ret(r);
+	long ts32[2];
+	r = __syscall(SYS_clock_gettime, clk, ts32);
+	if (r==-ENOSYS && clk==CLOCK_REALTIME) {
+		r = __syscall(SYS_gettimeofday, ts32, 0);
+		ts32[1] *= 1000;
 	}
-	return cgt(clk, ts);
+	if (!r) {
+		ts->tv_sec = ts32[0];
+		ts->tv_nsec = ts32[1];
+		return r;
+	}
+	return __syscall_ret(r);
 #else
-	return sc_clock_gettime(clk, ts);
+	r = __syscall(SYS_clock_gettime, clk, ts);
+	if (r == -ENOSYS) {
+		if (clk == CLOCK_REALTIME) {
+			__syscall(SYS_gettimeofday, ts, 0);
+			ts->tv_nsec = (int)ts->tv_nsec * 1000;
+			return 0;
+		}
+		r = -EINVAL;
+	}
+	return __syscall_ret(r);
 #endif
 }