[tip:x86/asm] x86/asm: Make objtool unreachable macros independent from GCC version

[tip-bot for Josh Poimboeuf]

Commit-ID:  1ee6f00d1164955b7bdadd36fc0f2736754784d9
Gitweb: http://git.kernel.org/tip/1ee6f00d1164955b7bdadd36fc0f2736754784d9
Author: Josh Poimboeuf 
AuthorDate: Tue, 25 Jul 2017 09:44:51 -0500
Committer:  Ingo Molnar 
CommitDate: Tue, 25 Jul 2017 16:54:07 +0200

x86/asm: Make objtool unreachable macros independent from GCC version

The ASM_UNREACHABLE macro isn't GCC version-specific, so move it outside
the GCC 4.5+ check.  Otherwise the 0-day robot will report objtool
warnings for uses of ASM_UNREACHABLE with GCC 4.4.

Also move the annotate_unreachable() macro so the related macros can
stay together.

Reported-by: kbuild test robot 
Signed-off-by: Josh Poimboeuf 
Cc: Kees Cook 
Cc: Linus Torvalds 
Cc: Peter Zijlstra 
Cc: Thomas Gleixner 
Fixes: aa5d1b81500e ("x86/asm: Add ASM_UNREACHABLE")
Link: 
http://lkml.kernel.org/r/fb18337dbf230fd36450d9faf19a2b2533dbcba1.1500993873.git.jpoim...@redhat.com
Signed-off-by: Ingo Molnar 
---
 include/linux/compiler-gcc.h | 32 
 1 file changed, 16 insertions(+), 16 deletions(-)

diff --git a/include/linux/compiler-gcc.h b/include/linux/compiler-gcc.h
index 179375b..17cbe3c 100644
--- a/include/linux/compiler-gcc.h
+++ b/include/linux/compiler-gcc.h
@@ -128,6 +128,22 @@
 #define __always_unused__attribute__((unused))
 #define __mode(x)   __attribute__((mode(x)))
 
+#ifdef CONFIG_STACK_VALIDATION
+#define annotate_unreachable() ({  \
+   asm("%c0:\n\t"  \
+   ".pushsection .discard.unreachable\n\t" \
+   ".long %c0b - .\n\t"\
+   ".popsection\n\t" : : "i" (__LINE__));  \
+})
+#define ASM_UNREACHABLE
\
+   "999:\n\t"  \
+   ".pushsection .discard.unreachable\n\t" \
+   ".long 999b - .\n\t"\
+   ".popsection\n\t"
+#else
+#define annotate_unreachable()
+#endif
+
 /* gcc version specific checks */
 
 #if GCC_VERSION < 30200
@@ -201,22 +217,6 @@
 #endif
 #endif
 
-#ifdef CONFIG_STACK_VALIDATION
-#define annotate_unreachable() ({  \
-   asm("%c0:\n\t"  \
-   ".pushsection .discard.unreachable\n\t" \
-   ".long %c0b - .\n\t"\
-   ".popsection\n\t" : : "i" (__LINE__));  \
-})
-#define ASM_UNREACHABLE
\
-   "999:\n\t"  \
-   ".pushsection .discard.unreachable\n\t" \
-   ".long 999b - .\n\t"\
-   ".popsection\n\t"
-#else
-#define annotate_unreachable()
-#endif
-
 /*
  * Mark a position in code as unreachable.  This can be used to
  * suppress control flow warnings after asm blocks that transfer

[tip:x86/asm] x86/asm: Make objtool unreachable macros independent from GCC version

[tip-bot for Josh Poimboeuf]

Commit-ID:  1ee6f00d1164955b7bdadd36fc0f2736754784d9
Gitweb: http://git.kernel.org/tip/1ee6f00d1164955b7bdadd36fc0f2736754784d9
Author: Josh Poimboeuf 
AuthorDate: Tue, 25 Jul 2017 09:44:51 -0500
Committer:  Ingo Molnar 
CommitDate: Tue, 25 Jul 2017 16:54:07 +0200

x86/asm: Make objtool unreachable macros independent from GCC version

The ASM_UNREACHABLE macro isn't GCC version-specific, so move it outside
the GCC 4.5+ check.  Otherwise the 0-day robot will report objtool
warnings for uses of ASM_UNREACHABLE with GCC 4.4.

Also move the annotate_unreachable() macro so the related macros can
stay together.

Reported-by: kbuild test robot 
Signed-off-by: Josh Poimboeuf 
Cc: Kees Cook 
Cc: Linus Torvalds 
Cc: Peter Zijlstra 
Cc: Thomas Gleixner 
Fixes: aa5d1b81500e ("x86/asm: Add ASM_UNREACHABLE")
Link: 
http://lkml.kernel.org/r/fb18337dbf230fd36450d9faf19a2b2533dbcba1.1500993873.git.jpoim...@redhat.com
Signed-off-by: Ingo Molnar 
---
 include/linux/compiler-gcc.h | 32 
 1 file changed, 16 insertions(+), 16 deletions(-)

diff --git a/include/linux/compiler-gcc.h b/include/linux/compiler-gcc.h
index 179375b..17cbe3c 100644
--- a/include/linux/compiler-gcc.h
+++ b/include/linux/compiler-gcc.h
@@ -128,6 +128,22 @@
 #define __always_unused__attribute__((unused))
 #define __mode(x)   __attribute__((mode(x)))
 
+#ifdef CONFIG_STACK_VALIDATION
+#define annotate_unreachable() ({  \
+   asm("%c0:\n\t"  \
+   ".pushsection .discard.unreachable\n\t" \
+   ".long %c0b - .\n\t"\
+   ".popsection\n\t" : : "i" (__LINE__));  \
+})
+#define ASM_UNREACHABLE
\
+   "999:\n\t"  \
+   ".pushsection .discard.unreachable\n\t" \
+   ".long 999b - .\n\t"\
+   ".popsection\n\t"
+#else
+#define annotate_unreachable()
+#endif
+
 /* gcc version specific checks */
 
 #if GCC_VERSION < 30200
@@ -201,22 +217,6 @@
 #endif
 #endif
 
-#ifdef CONFIG_STACK_VALIDATION
-#define annotate_unreachable() ({  \
-   asm("%c0:\n\t"  \
-   ".pushsection .discard.unreachable\n\t" \
-   ".long %c0b - .\n\t"\
-   ".popsection\n\t" : : "i" (__LINE__));  \
-})
-#define ASM_UNREACHABLE
\
-   "999:\n\t"  \
-   ".pushsection .discard.unreachable\n\t" \
-   ".long 999b - .\n\t"\
-   ".popsection\n\t"
-#else
-#define annotate_unreachable()
-#endif
-
 /*
  * Mark a position in code as unreachable.  This can be used to
  * suppress control flow warnings after asm blocks that transfer