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@decadent.org.uk>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-kernel@vger.kernel.org
Link: http://lkml.kernel.org/r/1443660043.2730.15.camel@decadent.org.uk
Signed-off-by: Ingo Molnar <mingo@kernel.org>

diff --git a/arch/x86/include/uapi/asm/bitsperlong.h b/arch/x86/include/uapi/asm/bitsperlong.h
index b0ae1c4dc79142d9284d14e76ac181f1c271ad64..217909b4d6f56d84892655f680f974eaf83ec78e 100644 (file)
--- 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