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authorUlrich Drepper <drepper@gmail.com>2011-05-27 16:09:52 -0400
committerUlrich Drepper <drepper@gmail.com>2011-05-27 16:09:52 -0400
commita8509ca540427502bd955f35296ff7b727c7a8a1 (patch)
tree964578fc90ec1cdd1b6af5b04dc0a4dd12fa266e /sysdeps
parentfdc2fefe46db79f0a19f690531cd775fbbc2740f (diff)
downloadglibc-a8509ca540427502bd955f35296ff7b727c7a8a1.tar.gz
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Use getcpu definition from vDSO on x86-64
Diffstat (limited to 'sysdeps')
-rw-r--r--sysdeps/unix/sysv/linux/x86_64/init-first.c12
-rw-r--r--sysdeps/unix/sysv/linux/x86_64/sched_getcpu.S7
2 files changed, 17 insertions, 2 deletions
diff --git a/sysdeps/unix/sysv/linux/x86_64/init-first.c b/sysdeps/unix/sysv/linux/x86_64/init-first.c
index ead7dbcc38..23934fc857 100644
--- a/sysdeps/unix/sysv/linux/x86_64/init-first.c
+++ b/sysdeps/unix/sysv/linux/x86_64/init-first.c
@@ -1,4 +1,4 @@
-/* Copyright (C) 2007 Free Software Foundation, Inc.
+/* Copyright (C) 2007, 2011 Free Software Foundation, Inc.
    This file is part of the GNU C Library.
 
    The GNU C Library is free software; you can redistribute it and/or
@@ -26,6 +26,8 @@ long int (*__vdso_clock_gettime) (clockid_t, struct timespec *)
   __attribute__ ((nocommon));
 strong_alias (__vdso_clock_gettime, __GI___vdso_clock_gettime attribute_hidden)
 
+long int (*__vdso_getcpu) (unsigned *, unsigned *, void *);
+
 
 static inline void
 _libc_vdso_platform_setup (void)
@@ -43,6 +45,14 @@ _libc_vdso_platform_setup (void)
   p = _dl_vdso_vsym ("clock_gettime", &linux26);
   PTR_MANGLE (p);
   __GI___vdso_clock_gettime = p;
+
+  p = _dl_vdso_vsym ("getcpu", &linux26);
+  /* If the vDSO is not available we fall back on the old vsyscall.  */
+#define VSYSCALL_ADDR_vgetcpu	0xffffffffff600800
+  if (p == NULL)
+    p = (void *) VSYSCALL_ADDR_vgetcpu;
+  PTR_MANGLE (p);
+  __vdso_getcpu = p;
 }
 
 # define VDSO_SETUP _libc_vdso_platform_setup
diff --git a/sysdeps/unix/sysv/linux/x86_64/sched_getcpu.S b/sysdeps/unix/sysv/linux/x86_64/sched_getcpu.S
index a950990627..8ec7d3fcd2 100644
--- a/sysdeps/unix/sysv/linux/x86_64/sched_getcpu.S
+++ b/sysdeps/unix/sysv/linux/x86_64/sched_getcpu.S
@@ -1,4 +1,4 @@
-/* Copyright (C) 2007 Free Software Foundation, Inc.
+/* Copyright (C) 2007, 2011 Free Software Foundation, Inc.
    This file is part of the GNU C Library.
 
    The GNU C Library is free software; you can redistribute it and/or
@@ -35,7 +35,12 @@ ENTRY (sched_getcpu)
 	movl	$VGETCPU_CACHE_OFFSET, %edx
 	addq	%fs:0, %rdx
 
+#ifdef SHARED
+	movq	__vdso_getcpu(%rip), %rax
+	PTR_DEMANGLE (%rax)
+#else
 	movq	$VSYSCALL_ADDR_vgetcpu, %rax
+#endif
 	callq	*%rax
 
 	cmpq	$-4095, %rax