Commit 68c467cb authored Dec 16, 2019 by David Sterba

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 <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>

parent a69976bc

fs/btrfs/ctree.h

+12 −8

Original line number	Diff line number	Diff line
		@@ -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();
		}
		}

		#define ASSERT(expr) \
		(likely(expr) ? (void)0 : assfail(#expr, __FILE__, __LINE__))
		(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

Admin message