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authorJeremy Fitzhardinge <jeremy@goop.org>2009-09-03 14:31:44 -0700
committerIngo Molnar <mingo@elte.hu>2009-09-04 07:10:31 +0200
commit53f824520b6d84ca5b4a8fd71addc91dbf64357e (patch)
treefc62733de8040f13cf450b6cae967976da31827b
parentx86/i386: Make sure stack-protector segment base is cache aligned (diff)
downloadlinux-dev-53f824520b6d84ca5b4a8fd71addc91dbf64357e.tar.xz
linux-dev-53f824520b6d84ca5b4a8fd71addc91dbf64357e.zip
x86/i386: Put aligned stack-canary in percpu shared_aligned section
Pack aligned things together into a special section to minimize padding holes. Suggested-by: Eric Dumazet <eric.dumazet@gmail.com> Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com> Cc: Tejun Heo <tj@kernel.org> LKML-Reference: <4AA035C0.9070202@goop.org> [ queued up in tip:x86/asm because it depends on this commit: x86/i386: Make sure stack-protector segment base is cache aligned ] Signed-off-by: Ingo Molnar <mingo@elte.hu>
-rw-r--r--arch/x86/include/asm/processor.h2
-rw-r--r--arch/x86/kernel/cpu/common.c2
-rw-r--r--include/asm-generic/percpu.h3
-rw-r--r--include/linux/percpu-defs.h8
4 files changed, 13 insertions, 2 deletions
diff --git a/arch/x86/include/asm/processor.h b/arch/x86/include/asm/processor.h
index e597ecc8753c..ac7e79654f3a 100644
--- a/arch/x86/include/asm/processor.h
+++ b/arch/x86/include/asm/processor.h
@@ -413,7 +413,7 @@ struct stack_canary {
char __pad[20]; /* canary at %gs:20 */
unsigned long canary;
};
-DECLARE_PER_CPU(struct stack_canary, stack_canary) ____cacheline_aligned;
+DECLARE_PER_CPU_ALIGNED(struct stack_canary, stack_canary);
#endif
#endif /* X86_64 */
diff --git a/arch/x86/kernel/cpu/common.c b/arch/x86/kernel/cpu/common.c
index 7d84bc4c1188..f23e236391a3 100644
--- a/arch/x86/kernel/cpu/common.c
+++ b/arch/x86/kernel/cpu/common.c
@@ -1043,7 +1043,7 @@ DEFINE_PER_CPU(struct orig_ist, orig_ist);
#else /* CONFIG_X86_64 */
#ifdef CONFIG_CC_STACKPROTECTOR
-DEFINE_PER_CPU(struct stack_canary, stack_canary) ____cacheline_aligned;
+DEFINE_PER_CPU_ALIGNED(struct stack_canary, stack_canary);
#endif
/* Make sure %fs and %gs are initialized properly in idle threads */
diff --git a/include/asm-generic/percpu.h b/include/asm-generic/percpu.h
index aa00800adacc..90079c373f1c 100644
--- a/include/asm-generic/percpu.h
+++ b/include/asm-generic/percpu.h
@@ -81,14 +81,17 @@ extern void setup_per_cpu_areas(void);
#ifdef MODULE
#define PER_CPU_SHARED_ALIGNED_SECTION ""
+#define PER_CPU_ALIGNED_SECTION ""
#else
#define PER_CPU_SHARED_ALIGNED_SECTION ".shared_aligned"
+#define PER_CPU_ALIGNED_SECTION ".shared_aligned"
#endif
#define PER_CPU_FIRST_SECTION ".first"
#else
#define PER_CPU_SHARED_ALIGNED_SECTION ""
+#define PER_CPU_ALIGNED_SECTION ".shared_aligned"
#define PER_CPU_FIRST_SECTION ""
#endif
diff --git a/include/linux/percpu-defs.h b/include/linux/percpu-defs.h
index 68438e18fff4..3058cf9dd3d4 100644
--- a/include/linux/percpu-defs.h
+++ b/include/linux/percpu-defs.h
@@ -66,6 +66,14 @@
DEFINE_PER_CPU_SECTION(type, name, PER_CPU_SHARED_ALIGNED_SECTION) \
____cacheline_aligned_in_smp
+#define DECLARE_PER_CPU_ALIGNED(type, name) \
+ DECLARE_PER_CPU_SECTION(type, name, PER_CPU_ALIGNED_SECTION) \
+ ____cacheline_aligned
+
+#define DEFINE_PER_CPU_ALIGNED(type, name) \
+ DEFINE_PER_CPU_SECTION(type, name, PER_CPU_ALIGNED_SECTION) \
+ ____cacheline_aligned
+
/*
* Declaration/definition used for per-CPU variables that must be page aligned.
*/