[glibc] sysdeps: Add clock_gettime64 vDSO

[glibc] sysdeps: Add clock_gettime64 vDSO

[Alistair Francis]

https://sourceware.org/git/gitweb.cgi?p=glibc.git;h=f6fbce7dd72145ed9272ac8ef3ea6123c390a72b

commit f6fbce7dd72145ed9272ac8ef3ea6123c390a72b
Author: Alistair Francis <alistair.francis@wdc.com>
Date:   Wed Sep 18 08:37:58 2019 -0700

    sysdeps: Add clock_gettime64 vDSO
    
    Add support for the clock_gettim64 vDSO calls. These are protected by
    the HAVE_CLOCK_GETTIME64_VSYSCALL define.
    
    HAVE_CLOCK_GETTIME64_VSYSCALL should be defined for 32-bit platforms
    (WORDSIZE == 32) that only run on the 5.1 kernel or later. WORDSIZE ==
    64 platforms can use #define __vdso_clock_gettime64 __vdso_clock_gettime
    and use the __vdso_clock_gettime syscall as they don't have a
    __vdso_clock_gettime64 call.
    
    Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>

Diff:
---
 sysdeps/unix/sysv/linux/init-first.c | 10 ++++++++++
 sysdeps/unix/sysv/linux/libc-vdso.h  |  4 ++++
 2 files changed, 14 insertions(+)

diff --git a/sysdeps/unix/sysv/linux/init-first.c b/sysdeps/unix/sysv/linux/init-first.c
index d90ca82..d005d13 100644
--- a/sysdeps/unix/sysv/linux/init-first.c
+++ b/sysdeps/unix/sysv/linux/init-first.c
@@ -24,6 +24,11 @@
 int (*VDSO_SYMBOL(clock_gettime)) (clockid_t, struct timespec *)
   attribute_hidden;
 #endif
+/* vDSO symbol used on clock_gettime64 implementation.  */
+#ifdef HAVE_CLOCK_GETTIME64_VSYSCALL
+int (*VDSO_SYMBOL(clock_gettime64)) (clockid_t, struct __timespec64 *)
+  attribute_hidden;
+#endif
 /* vDSO symbol used on clock_getres implementation.  */
 #ifdef HAVE_CLOCK_GETRES_VSYSCALL
 int (*VDSO_SYMBOL(clock_getres)) (clockid_t, struct timespec *)
@@ -52,6 +57,11 @@ __libc_vdso_platform_setup (void)
     = get_vdso_mangle_symbol (HAVE_CLOCK_GETTIME_VSYSCALL);
 #endif
 
+#ifdef HAVE_CLOCK_GETTIME64_VSYSCALL
+  VDSO_SYMBOL(clock_gettime64)
+    = get_vdso_mangle_symbol (HAVE_CLOCK_GETTIME64_VSYSCALL);
+#endif
+
 #ifdef HAVE_CLOCK_GETRES_VSYSCALL
   VDSO_SYMBOL(clock_getres)
     = get_vdso_mangle_symbol (HAVE_CLOCK_GETRES_VSYSCALL);
diff --git a/sysdeps/unix/sysv/linux/libc-vdso.h b/sysdeps/unix/sysv/linux/libc-vdso.h
index 792ac39..c6d505b 100644
--- a/sysdeps/unix/sysv/linux/libc-vdso.h
+++ b/sysdeps/unix/sysv/linux/libc-vdso.h
@@ -32,6 +32,10 @@
 extern int (*VDSO_SYMBOL(clock_gettime)) (clockid_t, struct timespec *)
   attribute_hidden;
 #endif
+#ifdef HAVE_CLOCK_GETTIME64_VSYSCALL
+extern int (*VDSO_SYMBOL(clock_gettime64)) (clockid_t, struct __timespec64 *)
+  attribute_hidden;
+#endif
 #ifdef HAVE_CLOCK_GETRES_VSYSCALL
 extern int (*VDSO_SYMBOL(clock_getres)) (clockid_t, struct timespec *)
   attribute_hidden;