From: David Sterba <dsterba@suse.cz>
To: dsterba@suse.cz, Josh Poimboeuf <jpoimboe@redhat.com>,
Randy Dunlap <rdunlap@infradead.org>,
Stephen Rothwell <sfr@canb.auug.org.au>,
Linux Next Mailing List <linux-next@vger.kernel.org>,
Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
Linux Btrfs <linux-btrfs@vger.kernel.org>,
Peter Zijlstra <peterz@infradead.org>
Subject: Re: linux-next: Tree for Dec 6 (objtool, lots in btrfs)
Date: Fri, 10 Jan 2020 20:46:22 +0100 [thread overview]
Message-ID: <20200110194622.GS3929@twin.jikos.cz> (raw)
In-Reply-To: <20191217152954.GH3929@suse.cz>
On Tue, Dec 17, 2019 at 04:29:54PM +0100, David Sterba wrote:
> Separating the definitions by #ifdef looks ok, I'd rather do separate
> definitions of ASSERT too, to avoid the ternary operator. I'll send the
> patch.
Subject: [PATCH] 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.
CC: Josh Poimboeuf <jpoimboe@redhat.com>
Reported-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: David Sterba <dsterba@suse.com>
---
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 569931dd0ce5..f90b82050d2d 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
--
next prev parent reply other threads:[~2020-01-10 19:46 UTC|newest]
Thread overview: 18+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <20191206135406.563336e7@canb.auug.org.au>
2019-12-06 16:17 ` linux-next: Tree for Dec 6 (objtool, lots in btrfs) Randy Dunlap
2019-12-11 13:49 ` David Sterba
2019-12-11 16:21 ` Randy Dunlap
2019-12-12 18:47 ` Josh Poimboeuf
2019-12-12 20:25 ` Randy Dunlap
[not found] ` <ba2a7a9b-933b-d4e4-8970-85b6c1291fca@infradead.org>
2019-12-13 23:50 ` Josh Poimboeuf
2019-12-14 0:04 ` Randy Dunlap
2019-12-14 5:45 ` Josh Poimboeuf
[not found] ` <fe1e0318-9b74-7ae0-07bd-d7a6c908e79a@infradead.org>
2019-12-17 15:25 ` David Sterba
2020-01-17 17:26 ` Josh Poimboeuf
2020-01-17 20:28 ` Marco Elver
2020-01-17 21:26 ` Josh Poimboeuf
2020-01-17 22:22 ` Josh Poimboeuf
2019-12-17 15:29 ` David Sterba
2020-01-10 19:46 ` David Sterba [this message]
2020-01-17 15:28 ` Josh Poimboeuf
2020-01-17 16:50 ` David Sterba
2020-01-17 17:03 ` Josh Poimboeuf
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