On Fri, Apr 03, 2015 at 02:05:17PM +0200, Borislav Petkov wrote:
> Let me do a patch.

---
From: Borislav Petkov <[email protected]>
Date: Fri, 3 Apr 2015 14:22:00 +0200
Subject: [PATCH] x86/asm/entry/64: Use a define for an invalid segment
 selector

... instead of a naked number, for better readability.

Signed-off-by: Borislav Petkov <[email protected]>
---
 arch/x86/include/asm/segment.h | 2 ++
 arch/x86/kernel/cpu/common.c   | 2 +-
 2 files changed, 3 insertions(+), 1 deletion(-)

diff --git a/arch/x86/include/asm/segment.h b/arch/x86/include/asm/segment.h
index d394899e055c..5a9856eb12ba 100644
--- a/arch/x86/include/asm/segment.h
+++ b/arch/x86/include/asm/segment.h
@@ -39,6 +39,8 @@
 /* ... GDT has it cleared */
 #define SEGMENT_GDT            0x0
 
+#define GDT_ENTRY_INVALID_SEG  0
+
 #ifdef CONFIG_X86_32
 /*
  * The layout of the per-CPU GDT under Linux:
diff --git a/arch/x86/kernel/cpu/common.c b/arch/x86/kernel/cpu/common.c
index 2c249b57e4b5..a62cf04dac8a 100644
--- a/arch/x86/kernel/cpu/common.c
+++ b/arch/x86/kernel/cpu/common.c
@@ -1223,7 +1223,7 @@ void syscall_init(void)
        wrmsrl_safe(MSR_IA32_SYSENTER_EIP, (u64)ia32_sysenter_target);
 #else
        wrmsrl(MSR_CSTAR, ignore_sysret);
-       wrmsrl_safe(MSR_IA32_SYSENTER_CS, 0ULL);
+       wrmsrl_safe(MSR_IA32_SYSENTER_CS, (u64)GDT_ENTRY_INVALID_SEG);
        wrmsrl_safe(MSR_IA32_SYSENTER_ESP, 0ULL);
        wrmsrl_safe(MSR_IA32_SYSENTER_EIP, 0ULL);
 #endif
-- 
2.3.3

-- 
Regards/Gruss,
    Boris.

ECO tip #101: Trim your mails when you reply.
--
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to [email protected]
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/

Reply via email to