Patchwork [v3,1/2] sysdeps: Add clock_gettime64 vDSO

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Submitter Alistair Francis
Date Nov. 23, 2019, 10:27 p.m.
Message ID <20191123222708.17021-1-alistair.francis@wdc.com>
Download mbox | patch
Permalink /patch/36158/
State New
Headers show

Comments

Alistair Francis - Nov. 23, 2019, 10:27 p.m.
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>
---
 sysdeps/unix/sysv/linux/init-first.c | 10 ++++++++++
 sysdeps/unix/sysv/linux/libc-vdso.h  |  4 ++++
 2 files changed, 14 insertions(+)

Patch

diff --git a/sysdeps/unix/sysv/linux/init-first.c b/sysdeps/unix/sysv/linux/init-first.c
index d90ca820be..d005d13322 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 792ac39d85..c6d505bab3 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;