btrfs: separate definition of assertion failure handlers

[ Upstream commit 68c467cbb2 ]

There's a report where objtool detects unreachable instructions, eg.:

  fs/btrfs/ctree.o: warning: objtool: btrfs_search_slot()+0x2d4: unreachable instruction

This seems to be a false positive due to compiler version. The cause is
in the ASSERT macro implementation that does the conditional check as
IS_DEFINED(CONFIG_BTRFS_ASSERT) and not an #ifdef.

To avoid that, use the ifdefs directly.

There are still 2 reports that aren't fixed:

  fs/btrfs/extent_io.o: warning: objtool: __set_extent_bit()+0x71f: unreachable instruction
  fs/btrfs/relocation.o: warning: objtool: find_data_references()+0x4e0: unreachable instruction

Co-developed-by: Josh Poimboeuf <jpoimboe@redhat.com>
Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
Reported-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
This commit is contained in:
David Sterba 2019-12-16 20:00:48 +01:00 committed by Greg Kroah-Hartman
parent 3420f1b304
commit dc22bc8a86

View file

@ -3107,17 +3107,21 @@ do { \
rcu_read_unlock(); \
} while (0)
__cold
static inline void assfail(const char *expr, const char *file, int line)
#ifdef CONFIG_BTRFS_ASSERT
__cold __noreturn
static inline void assertfail(const char *expr, const char *file, int line)
{
if (IS_ENABLED(CONFIG_BTRFS_ASSERT)) {
pr_err("assertion failed: %s, in %s:%d\n", expr, file, line);
BUG();
}
pr_err("assertion failed: %s, in %s:%d\n", expr, file, line);
BUG();
}
#define ASSERT(expr) \
(likely(expr) ? (void)0 : assfail(#expr, __FILE__, __LINE__))
#define ASSERT(expr) \
(likely(expr) ? (void)0 : assertfail(#expr, __FILE__, __LINE__))
#else
static inline void assertfail(const char *expr, const char* file, int line) { }
#define ASSERT(expr) (void)(expr)
#endif
/*
* Use that for functions that are conditionally exported for sanity tests but