From: David Sterba Date: Mon, 16 Dec 2019 19:00:48 +0000 (+0100) Subject: btrfs: separate definition of assertion failure handlers X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=68c467cbb2f389b6c933e235bce0d1756fc8cc34;p=linux.git btrfs: separate definition of assertion failure handlers 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 Signed-off-by: Josh Poimboeuf Reported-by: Randy Dunlap Signed-off-by: David Sterba --- diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h index 569931dd0ce55..f90b82050d2db 100644 --- a/fs/btrfs/ctree.h +++ b/fs/btrfs/ctree.h @@ -3157,17 +3157,21 @@ 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