locking/lockdep: Avoid a Clang warning

arndb · Ingo Molnar · commit 3fe7522fb766 · 2019-03-09T14:15:51.000+01:00
Clang warns about a tentative array definition without a length: kernel/locking/lockdep.c:845:12: error: tentative array definition assumed to have one element [-Werror] There is no real reason to do this here, so just set the same length as in the real definition later in the same file. It has to be hidden in an #ifdef or annotated __maybe_unused though, to avoid the unused-variable warning if CONFIG_PROVE_LOCKING is disabled. Signed-off-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Andy Lutomirski <luto@kernel.org> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Bart Van Assche <bvanassche@acm.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Frederic Weisbecker <frederic@kernel.org> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Joel Fernandes (Google) <joel@joelfernandes.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rik van Riel <riel@surriel.com> Cc: Stephane Eranian <eranian@google.com> Cc: Steven Rostedt (VMware) <rostedt@goodmis.org> Cc: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vince Weaver <vincent.weaver@maine.edu> Cc: Waiman Long <longman@redhat.com> Cc: Will Deacon <will.deacon@arm.com> Link: https://lkml.kernel.org/r/20190307075222.3424524-1-arnd@arndb.de Signed-off-by: Ingo Molnar <mingo@kernel.org>
diff --git a/kernel/locking/lockdep.c b/kernel/locking/lockdep.c
@@ -842,7 +842,9 @@ static bool class_lock_list_valid(struct lock_class *c, struct list_head *h)
 	return true;
 }
 
-static u16 chain_hlocks[];
+#ifdef CONFIG_PROVE_LOCKING
+static u16 chain_hlocks[MAX_LOCKDEP_CHAIN_HLOCKS];
+#endif
 
 static bool check_lock_chain_key(struct lock_chain *chain)
 {

Original file line number	Diff line number	Diff line change
`@@ -842,7 +842,9 @@ static bool class_lock_list_valid(struct lock_class c, struct list_head h)`
`842`	`842`	`return true;`
`843`	`843`	`}`
`844`	`844`
`845`		`-static u16 chain_hlocks[];`
	`845`	`+#ifdef CONFIG_PROVE_LOCKING`
	`846`	`+static u16 chain_hlocks[MAX_LOCKDEP_CHAIN_HLOCKS];`
	`847`	`+#endif`
`846`	`848`
`847`	`849`	`static bool check_lock_chain_key(struct lock_chain *chain)`
`848`	`850`	`{`