PowerPC: Fix gettimeofday ifunc selection

The IFUNC selector for gettimeofday runs before _libc_vdso_platform_setup where
__vdso_gettimeofday is set. The selector then sets __gettimeofday (the internal
version used within GLIBC) to use the system call version instead of the vDSO one.
This patch changes the check if vDSO is available to get its value directly
instead of rely on __vdso_gettimeofday.

This patch changes it by getting the vDSO value directly.

It fixes BZ#16431.

2 files changed, 10 insertions, 4 deletions

diff --git a/sysdeps/unix/sysv/linux/powerpc/gettimeofday.c b/sysdeps/unix/sysv/linux/powerpc/gettimeofday.c
index 2085b68772..97ea2a4a70 100644
--- a/sysdeps/unix/sysv/linux/powerpc/gettimeofday.c
+++ b/sysdeps/unix/sysv/linux/powerpc/gettimeofday.c
@@ -35,9 +35,12 @@ __gettimeofday_syscall (struct timeval *tv, struct timezone *tz)
 void *
 gettimeofday_ifunc (void)
 {
+  PREPARE_VERSION (linux2615, "LINUX_2.6.15", 123718565);
+
   /* If the vDSO is not available we fall back syscall.  */
-  return (__vdso_gettimeofday ? VDSO_IFUNC_RET (__vdso_gettimeofday)
-	  : __gettimeofday_syscall);
+  void *vdso_gettimeofday = _dl_vdso_vsym ("__kernel_gettimeofday", &linux2615);
+  return (vdso_gettimeofday ? VDSO_IFUNC_RET (vdso_gettimeofday)
+	  : (void*)__gettimeofday_syscall);
 }
 asm (".type __gettimeofday, %gnu_indirect_function");
 
diff --git a/sysdeps/unix/sysv/linux/powerpc/time.c b/sysdeps/unix/sysv/linux/powerpc/time.c
index 023bc026be..9f54d97246 100644
--- a/sysdeps/unix/sysv/linux/powerpc/time.c
+++ b/sysdeps/unix/sysv/linux/powerpc/time.c
@@ -45,9 +45,12 @@ time_syscall (time_t *t)
 void *
 time_ifunc (void)
 {
+  PREPARE_VERSION (linux2615, "LINUX_2.6.15", 123718565);
+
   /* If the vDSO is not available we fall back to the syscall.  */
-  return (__vdso_time ? VDSO_IFUNC_RET (__vdso_time)
-	  : time_syscall);
+  void *vdso_time = _dl_vdso_vsym ("__kernel_time", &linux2615);
+  return (vdso_time ? VDSO_IFUNC_RET (vdso_time)
+	  : (void*)time_syscall);
 }
 asm (".type time, %gnu_indirect_function");