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authorJosh Poimboeuf <jpoimboe@redhat.com>2018-02-09 02:09:26 +0300
committerIngo Molnar <mingo@kernel.org>2018-02-15 03:15:49 +0300
commit2b5db66862b95532cb6cca8165ae6eb73633cf85 (patch)
tree4215ccf5a9f380f0031a9baee50d80b9fff42038
parentfe24e27128252c230a34a6c628da2bf1676781ea (diff)
downloadlinux-2b5db66862b95532cb6cca8165ae6eb73633cf85.tar.xz
x86/debug, objtool: Annotate WARN()-related UD2 as reachable
By default, objtool assumes that a UD2 is a dead end. This is mainly because GCC 7+ sometimes inserts a UD2 when it detects a divide-by-zero condition. Now that WARN() is moving back to UD2, annotate the code after it as reachable so objtool can follow the code flow. Reported-by: Borislav Petkov <bp@alien8.de> Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Andy Lutomirski <luto@kernel.org> Cc: Arjan van de Ven <arjan@linux.intel.com> Cc: Brian Gerst <brgerst@gmail.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: kbuild test robot <fengguang.wu@intel.com> Link: http://lkml.kernel.org/r/0e483379275a42626ba8898117f918e1bf661e40.1518130694.git.jpoimboe@redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
-rw-r--r--arch/x86/include/asm/bug.h6
1 files changed, 5 insertions, 1 deletions
diff --git a/arch/x86/include/asm/bug.h b/arch/x86/include/asm/bug.h
index 34d99af43994..71e6f4bf9161 100644
--- a/arch/x86/include/asm/bug.h
+++ b/arch/x86/include/asm/bug.h
@@ -77,7 +77,11 @@ do { \
unreachable(); \
} while (0)
-#define __WARN_FLAGS(flags) _BUG_FLAGS(ASM_UD0, BUGFLAG_WARNING|(flags))
+#define __WARN_FLAGS(flags) \
+do { \
+ _BUG_FLAGS(ASM_UD0, BUGFLAG_WARNING|(flags)); \
+ annotate_reachable(); \
+} while (0)
#include <asm-generic/bug.h>