From: David Sterba dsterba@suse.com
[ Upstream commit 68c467cbb2f389b6c933e235bce0d1756fc8cc34 ]
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 --- fs/btrfs/ctree.h | 20 ++++++++++++-------- 1 file changed, 12 insertions(+), 8 deletions(-)
diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h index 290ca193c6c0f..169075550a5a2 100644 --- a/fs/btrfs/ctree.h +++ b/fs/btrfs/ctree.h @@ -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