[tip:x86/urgent] x86/headers/uapi: Fix __BITS_PER_LONG value for x32 builds

[tip-bot for Ben Hutchings]

Commit-ID:  f4b4aae1828855db761bf998ce37d3062b1d6446
Gitweb:     http://git.kernel.org/tip/f4b4aae1828855db761bf998ce37d3062b1d6446
Author:     Ben Hutchings <ben@xxxxxxxxxxxxxxx>
AuthorDate: Thu, 1 Oct 2015 01:40:43 +0100
Committer:  Ingo Molnar <mingo@xxxxxxxxxx>
CommitDate: Fri, 2 Oct 2015 09:43:21 +0200

x86/headers/uapi: Fix __BITS_PER_LONG value for x32 builds

On x32, gcc predefines __x86_64__ but long is only 32-bit.  Use
__ILP32__ to distinguish x32.

Fixes this compiler error in perf:

	tools/include/asm-generic/bitops/__ffs.h: In function '__ffs':
	tools/include/asm-generic/bitops/__ffs.h:19:8: error: right shift count >= width of type [-Werror=shift-count-overflow]
	  word >>= 32;
	       ^

This isn't sufficient to build perf for x32, though.

Signed-off-by: Ben Hutchings <ben@xxxxxxxxxxxxxxx>
Cc: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
Cc: Mike Galbraith <efault@xxxxxx>
Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Cc: linux-kernel@xxxxxxxxxxxxxxx
Link: http://lkml.kernel.org/r/1443660043.2730.15.camel@xxxxxxxxxxxxxxx
Signed-off-by: Ingo Molnar <mingo@xxxxxxxxxx>
---
 arch/x86/include/uapi/asm/bitsperlong.h | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/x86/include/uapi/asm/bitsperlong.h b/arch/x86/include/uapi/asm/bitsperlong.h
index b0ae1c4..217909b 100644
--- a/arch/x86/include/uapi/asm/bitsperlong.h
+++ b/arch/x86/include/uapi/asm/bitsperlong.h
@@ -1,7 +1,7 @@
 #ifndef __ASM_X86_BITSPERLONG_H
 #define __ASM_X86_BITSPERLONG_H
 
-#ifdef __x86_64__
+#if defined(__x86_64__) && !defined(__ILP32__)
 # define __BITS_PER_LONG 64
 #else
 # define __BITS_PER_LONG 32
--
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