From 7d317ec29c587f76bbfa375ef3b832204f5bffe5 Mon Sep 17 00:00:00 2001 From: Linus Torvalds Date: Sun, 12 Jul 2009 11:25:04 -0700 Subject: Don't use '-fwrapv' compiler option: it's buggy in gcc-4.1.x commit a137802ee839ace40079bebde24cfb416f73208a upstream. This causes kernel images that don't run init to completion with certain broken gcc versions. This fixes kernel bugzilla entry: http://bugzilla.kernel.org/show_bug.cgi?id=13012 I suspect the gcc problem is this: http://gcc.gnu.org/bugzilla/show_bug.cgi?id=28230 Fix the problem by using the -fno-strict-overflow flag instead, which not only does not exist in the known-to-be-broken versions of gcc (it was introduced later than fwrapv), but seems to be much less disturbing to gcc too: the difference in the generated code by -fno-strict-overflow are smaller (compared to using neither flag) than when using -fwrapv. Reported-by: Barry K. Nathan Pushed-by: Frans Pop Cc: Andrew Morton Signed-off-by: Linus Torvalds Signed-off-by: Greg Kroah-Hartman --- Makefile | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/Makefile b/Makefile index 9cbe9a4e23ed..55d3c417f135 100644 --- a/Makefile +++ b/Makefile @@ -557,7 +557,7 @@ KBUILD_CFLAGS += $(call cc-option,-Wdeclaration-after-statement,) KBUILD_CFLAGS += $(call cc-option,-Wno-pointer-sign,) # disable invalid "can't wrap" optimzations for signed / pointers -KBUILD_CFLAGS += $(call cc-option,-fwrapv) +KBUILD_CFLAGS += $(call cc-option,-fno-strict-overflow) # Add user supplied CPPFLAGS, AFLAGS and CFLAGS as the last assignments # But warn user when we do so -- cgit v1.2.3