Commit 32818c2e authored Aug 26, 2005 by Anton Blanchard Committed by Linus Torvalds Aug 26, 2005

[PATCH] ppc64: Fix issue with gcc 4.0 compiled kernels

I recently had a BUG_ON() go off spuriously on a gcc 4.0 compiled kernel.
It turns out gcc-4.0 was removing a sign extension while earlier gcc
versions would not.  Thinking this to be a compiler bug, I submitted a
report:

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=23422



It turns out we need to cast the input in order to tell gcc to sign extend
it.

Thanks to Andrew Pinski for his help on this bug.

Signed-off-by: Anton Blanchard <anton@samba.org>
Cc: Paul Mackerras <paulus@samba.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

parent 212d6d22

include/asm-ppc64/bug.h

+4 −3

Original line number	Diff line number	Diff line
		@@ -43,8 +43,8 @@ struct bug_entry *find_bug(unsigned long bugaddr);
		".section __bug_table,\"a\"\n\t" \
		" .llong 1b,%1,%2,%3\n" \
		".previous" \
		: : "r" (x), "i" (__LINE__), "i" (__FILE__), \
		"i" (__FUNCTION__)); \
		: : "r" ((long long)(x)), "i" (__LINE__), \
		"i" (__FILE__), "i" (__FUNCTION__)); \
		} while (0)

		#define WARN_ON(x) do { \
		@@ -53,7 +53,8 @@ struct bug_entry *find_bug(unsigned long bugaddr);
		".section __bug_table,\"a\"\n\t" \
		" .llong 1b,%1,%2,%3\n" \
		".previous" \
		: : "r" (x), "i" (__LINE__ + BUG_WARNING_TRAP), \
		: : "r" ((long long)(x)), \
		"i" (__LINE__ + BUG_WARNING_TRAP), \
		"i" (__FILE__), "i" (__FUNCTION__)); \
		} while (0)

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