Re: linux-next: Tree for Dec 6 (objtool, lots in btrfs)

[Josh Poimboeuf]

On Fri, Dec 13, 2019 at 04:04:58PM -0800, Randy Dunlap wrote:
> > diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h
> > index b2e8fd8a8e59..bbd68520f5f1 100644
> > --- a/fs/btrfs/ctree.h
> > +++ b/fs/btrfs/ctree.h
> > @@ -3110,14 +3110,16 @@ do {								\
> >  	rcu_read_unlock();					\
> >  } while (0)
> >  
> > -__cold
> > +#ifdef CONFIG_BTRFS_ASSERT
> > +__cold __unlikely
> 
> what provides __unlikely?  It is causing build errors.
> 
> and if I remove the "__unlikely", I still see the objtool warnings
> (unreachable instructions).

Ha, not sure how that happened... Should be __noreturn instead of
__unlikely.  Cheers...

diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h
index b2e8fd8a8e59..398bd010dfc5 100644
--- a/fs/btrfs/ctree.h
+++ b/fs/btrfs/ctree.h
@@ -3110,14 +3110,16 @@ do {								\
 	rcu_read_unlock();					\
 } while (0)
 
-__cold
+#ifdef CONFIG_BTRFS_ASSERT
+__cold __noreturn
 static inline void assfail(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();
 }
+#else
+static inline void assfail(const char *expr, const char *file, int line) {}
+#endif
 
 #define ASSERT(expr)	\
 	(likely(expr) ? (void)0 : assfail(#expr, __FILE__, __LINE__))