[tip:x86/urgent] x86/cpu: Fix duplicated X86_BUG(9) macro

From: tip-bot for Dave Hansen
Date: Sat Jul 09 2016 - 13:56:16 EST


Commit-ID: 8709ed4d4b0eab04561c1ec9e6ea50fd1e3897ff
Gitweb: http://git.kernel.org/tip/8709ed4d4b0eab04561c1ec9e6ea50fd1e3897ff
Author: Dave Hansen <dave.hansen@xxxxxxxxxxxxxxx>
AuthorDate: Fri, 17 Jun 2016 17:15:03 -0700
Committer: Ingo Molnar <mingo@xxxxxxxxxx>
CommitDate: Sat, 9 Jul 2016 14:06:06 +0200

x86/cpu: Fix duplicated X86_BUG(9) macro

cpufeatures.h currently defines X86_BUG(9) twice on 32-bit:

#define X86_BUG_NULL_SEG X86_BUG(9) /* Nulling a selector preserves the base */
...
#ifdef CONFIG_X86_32
#define X86_BUG_ESPFIX X86_BUG(9) /* "" IRET to 16-bit SS corrupts ESP/RSP high bits */
#endif

I think what happened was that this added the X86_BUG_ESPFIX, but
in an #ifdef below most of the bugs:

58a5aac53313 x86/entry/32: Introduce and use X86_BUG_ESPFIX instead of paravirt_enabled

Then this came along and added X86_BUG_NULL_SEG, but collided
with the earlier one that did the bug below the main block
defining all the X86_BUG()s.

7a5d67048745 x86/cpu: Probe the behavior of nulling out a segment at boot time

Signed-off-by: Dave Hansen <dave.hansen@xxxxxxxxxxxxxxx>
Acked-by: Andy Lutomirski <luto@xxxxxxxxxx>
Cc: Andy Lutomirski <luto@xxxxxxxxxxxxxx>
Cc: Borislav Petkov <bp@xxxxxxxxx>
Cc: Brian Gerst <brgerst@xxxxxxxxx>
Cc: Dave Hansen <dave@xxxxxxxx>
Cc: Denys Vlasenko <dvlasenk@xxxxxxxxxx>
Cc: H. Peter Anvin <hpa@xxxxxxxxx>
Cc: Josh Poimboeuf <jpoimboe@xxxxxxxxxx>
Cc: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Cc: stable@xxxxxxxxxxxxxxx
Link: http://lkml.kernel.org/r/20160618001503.CEE1B141@xxxxxxxxxxxxxxxxxx
Signed-off-by: Ingo Molnar <mingo@xxxxxxxxxx>
---
arch/x86/include/asm/cpufeatures.h | 6 ++----
1 file changed, 2 insertions(+), 4 deletions(-)

diff --git a/arch/x86/include/asm/cpufeatures.h b/arch/x86/include/asm/cpufeatures.h
index 4a41348..c64b1e9 100644
--- a/arch/x86/include/asm/cpufeatures.h
+++ b/arch/x86/include/asm/cpufeatures.h
@@ -301,10 +301,6 @@
#define X86_BUG_FXSAVE_LEAK X86_BUG(6) /* FXSAVE leaks FOP/FIP/FOP */
#define X86_BUG_CLFLUSH_MONITOR X86_BUG(7) /* AAI65, CLFLUSH required before MONITOR */
#define X86_BUG_SYSRET_SS_ATTRS X86_BUG(8) /* SYSRET doesn't fix up SS attrs */
-#define X86_BUG_NULL_SEG X86_BUG(9) /* Nulling a selector preserves the base */
-#define X86_BUG_SWAPGS_FENCE X86_BUG(10) /* SWAPGS without input dep on GS */
-
-
#ifdef CONFIG_X86_32
/*
* 64-bit kernels don't use X86_BUG_ESPFIX. Make the define conditional
@@ -312,5 +308,7 @@
*/
#define X86_BUG_ESPFIX X86_BUG(9) /* "" IRET to 16-bit SS corrupts ESP/RSP high bits */
#endif
+#define X86_BUG_NULL_SEG X86_BUG(10) /* Nulling a selector preserves the base */
+#define X86_BUG_SWAPGS_FENCE X86_BUG(11) /* SWAPGS without input dep on GS */

#endif /* _ASM_X86_CPUFEATURES_H */