Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit 101b29a2 authored by Johannes Berg's avatar Johannes Berg Committed by Linus Torvalds
Browse files

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: 7322dd75 ("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: default avatarJohannes Berg <johannes.berg@intel.com>
Acked-by: default avatarArnd Bergmann <arnd@arndb.de>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 61c04572

include/linux/compiler-gcc.h

+6 −2
Original line number Diff line number Diff line
@@ -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