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Subject[PATCH v2 3/8] x86/fsgsbase/64: Use FS/GS base helpers in core dump
Date
When new FSGSBASE instructions enabled, this read will
become faster.

Based-on-code-from: Andy Lutomirski <luto@kernel.org>
Signed-off-by: Chang S. Bae <chang.seok.bae@intel.com>
Reviewed-by: Andi Kleen <ak@linux.intel.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@kernel.org>
Reviewed-by: Andy Lutomirski <luto@kernel.org>
---
arch/x86/include/asm/elf.h | 6 +++---
1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/arch/x86/include/asm/elf.h b/arch/x86/include/asm/elf.h
index 0d157d2..49acefb 100644
--- a/arch/x86/include/asm/elf.h
+++ b/arch/x86/include/asm/elf.h
@@ -10,6 +10,7 @@
#include <asm/ptrace.h>
#include <asm/user.h>
#include <asm/auxvec.h>
+#include <asm/fsgsbase.h>

typedef unsigned long elf_greg_t;

@@ -205,7 +206,6 @@ void set_personality_ia32(bool);

#define ELF_CORE_COPY_REGS(pr_reg, regs) \
do { \
- unsigned long base; \
unsigned v; \
(pr_reg)[0] = (regs)->r15; \
(pr_reg)[1] = (regs)->r14; \
@@ -228,8 +228,8 @@ do { \
(pr_reg)[18] = (regs)->flags; \
(pr_reg)[19] = (regs)->sp; \
(pr_reg)[20] = (regs)->ss; \
- rdmsrl(MSR_FS_BASE, base); (pr_reg)[21] = base; \
- rdmsrl(MSR_KERNEL_GS_BASE, base); (pr_reg)[22] = base; \
+ (pr_reg)[21] = read_fsbase(); \
+ (pr_reg)[22] = read_inactive_gsbase(); \
asm("movl %%ds,%0" : "=r" (v)); (pr_reg)[23] = v; \
asm("movl %%es,%0" : "=r" (v)); (pr_reg)[24] = v; \
asm("movl %%fs,%0" : "=r" (v)); (pr_reg)[25] = v; \
--
2.7.4
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