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authorJohannes Berg <johannes.berg@intel.com>2016-08-25 15:16:45 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2016-08-26 17:39:34 -0700
commit101b29a204f87c99377faa53bd378f101ebb1824 (patch)
treec3cb59db61461cf85e05ed0daf6423148fb9ccb1
parent61c04572de404e52a655a36752e696bbcb483cf5 (diff)
downloadlinux-stericsson-101b29a204f87c99377faa53bd378f101ebb1824.tar.gz
byteswap: don't use __builtin_bswap*() with sparse
Although sparse declares __builtin_bswap*(), it can't actually do constant folding inside them (yet). As such, things like switch (protocol) { case htons(ETH_P_IP): break; } which we do all over the place cause sparse to warn that it expects a constant instead of a function call. Disable __HAVE_BUILTIN_BSWAP*__ if __CHECKER__ is defined to avoid this. Fixes: 7322dd755e7d ("byteswap: try to avoid __builtin_constant_p gcc bug") Link: http://lkml.kernel.org/r/1470914102-26389-1-git-send-email-johannes@sipsolutions.net Signed-off-by: Johannes Berg <johannes.berg@intel.com> Acked-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
-rw-r--r--include/linux/compiler-gcc.h8
1 files changed, 6 insertions, 2 deletions
diff --git a/include/linux/compiler-gcc.h b/include/linux/compiler-gcc.h
index e2949397c19b..8dbc8929a6a0 100644
--- a/include/linux/compiler-gcc.h
+++ b/include/linux/compiler-gcc.h
@@ -242,7 +242,11 @@
*/
#define asm_volatile_goto(x...) do { asm goto(x); asm (""); } while (0)
-#ifdef CONFIG_ARCH_USE_BUILTIN_BSWAP
+/*
+ * sparse (__CHECKER__) pretends to be gcc, but can't do constant
+ * folding in __builtin_bswap*() (yet), so don't set these for it.
+ */
+#if defined(CONFIG_ARCH_USE_BUILTIN_BSWAP) && !defined(__CHECKER__)
#if GCC_VERSION >= 40400
#define __HAVE_BUILTIN_BSWAP32__
#define __HAVE_BUILTIN_BSWAP64__
@@ -250,7 +254,7 @@
#if GCC_VERSION >= 40800
#define __HAVE_BUILTIN_BSWAP16__
#endif
-#endif /* CONFIG_ARCH_USE_BUILTIN_BSWAP */
+#endif /* CONFIG_ARCH_USE_BUILTIN_BSWAP && !__CHECKER__ */
#if GCC_VERSION >= 50000
#define KASAN_ABI_VERSION 4