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authorLinus Torvalds <torvalds@linux-foundation.org>2009-01-02 09:29:43 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2009-01-02 09:29:43 -0800
commitf9d14250071eda9972e4c9cea745a11185952114 (patch)
treea8839b522bf83b96a238bd6cb0e88093731a1e24
parentf153b82121b0366fe0e5f9553545cce237335175 (diff)
Disallow gcc versions 4.1.{0,1}
These compiler versions are known to miscompile __weak functions and thus generate kernels that don't necessarily work correctly. If a weak function is int he same compilation unit as a caller, gcc may end up inlining it, and thus binding the weak function too early. See http://gcc.gnu.org/bugzilla/show_bug.cgi?id=27781 for details. Cc: Adrian Bunk <bunk@kernel.org> Cc: Helge Deller <deller@gmx.de> Cc: Rusty Russell <rusty@rustcorp.com.au> Cc: Ingo Molnar <mingo@elte.hu> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
-rw-r--r--include/linux/compiler-gcc4.h5
1 files changed, 5 insertions, 0 deletions
diff --git a/include/linux/compiler-gcc4.h b/include/linux/compiler-gcc4.h
index aa426214331..09992718f9e 100644
--- a/include/linux/compiler-gcc4.h
+++ b/include/linux/compiler-gcc4.h
@@ -2,6 +2,11 @@
#error "Please don't include <linux/compiler-gcc4.h> directly, include <linux/compiler.h> instead."
#endif
+/* GCC 4.1.[01] miscompiles __weak */
+#if __GNUC_MINOR__ == 1 && __GNUC_PATCHLEVEL__ <= 1
+# error Your version of gcc miscompiles the __weak directive
+#endif
+
#define __used __attribute__((__used__))
#define __must_check __attribute__((warn_unused_result))
#define __compiler_offsetof(a,b) __builtin_offsetof(a,b)