Re: [Mjpeg-users] [linux-next:master] BUILD REGRESSION 6cc11d2a1759275b856e464265823d94aabd5eaf

[Roman G. <rom...@li...>]

esOn Fri, Jul 01, 2022 at 07:49:42AM +0800, kbuild test robot wrote:
> tree/branch: https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git master
> branch HEAD: 6cc11d2a1759275b856e464265823d94aabd5eaf  Add linux-next specific files for 20220630
> 
> Error/Warning reports:
> 
> https://lore.kernel.org/linux-mm/202...@in...
> 
> Error/Warning: (recently discovered and may have been fixed)
> 
> arch/powerpc/kernel/interrupt.c:542:55: error: suggest braces around empty body in an 'if' statement [-Werror=empty-body]
> arch/powerpc/kernel/interrupt.c:542:55: warning: suggest braces around empty body in an 'if' statement [-Wempty-body]
> drivers/pci/endpoint/functions/pci-epf-vntb.c:975:5: warning: no previous prototype for 'pci_read' [-Wmissing-prototypes]
> drivers/pci/endpoint/functions/pci-epf-vntb.c:984:5: warning: no previous prototype for 'pci_write' [-Wmissing-prototypes]
> mm/shrinker_debug.c:143:9: warning: function 'shrinker_debugfs_rename' might be a candidate for 'gnu_printf' format attribute [-Wsuggest-attribute=format]
> mm/shrinker_debug.c:217:9: warning: function 'shrinker_debugfs_rename' might be a candidate for 'gnu_printf' format attribute [-Wsuggest-attribute=format]
> mm/vmscan.c:637:9: warning: function 'prealloc_shrinker' might be a candidate for 'gnu_printf' format attribute [-Wsuggest-attribute=format]
> mm/vmscan.c:642:9: warning: function 'prealloc_shrinker' might be a candidate for 'gnu_printf' format attribute [-Wsuggest-attribute=format]
> mm/vmscan.c:697:9: warning: function 'register_shrinker' might be a candidate for 'gnu_printf' format attribute [-Wsuggest-attribute=format]
> mm/vmscan.c:702:9: warning: function 'register_shrinker' might be a candidate for 'gnu_printf' format attribute [-Wsuggest-attribute=format]

Shrinker-related warnings should be fixed by the following patch.

Thanks!

--

>From c399aff65c7745a209397a531c5b28fd404d83c2 Mon Sep 17 00:00:00 2001
From: Roman Gushchin <rom...@li...v>
Date: Fri, 1 Jul 2022 17:38:31 -0700
Subject: [PATCH] mm:shrinkers: fix build warnings

Add __printf(a, b) attributes to shrinker functions taking shrinker
name as an argument to avoid compiler warnings like:

mm/shrinker_debug.c:143:9: warning: function 'shrinker_debugfs_rename'
  might be a candidate for 'gnu_printf' format attribute [-Wsuggest-attribute=format]
mm/shrinker_debug.c:217:9: warning: function 'shrinker_debugfs_rename'
  might be a candidate for 'gnu_printf' format attribute [-Wsuggest-attribute=format]
mm/vmscan.c:637:9: warning: function 'prealloc_shrinker' might be a
  candidate for 'gnu_printf' format attribute [-Wsuggest-attribute=format]
mm/vmscan.c:642:9: warning: function 'prealloc_shrinker' might be a
  candidate for 'gnu_printf' format attribute [-Wsuggest-attribute=format]
mm/vmscan.c:697:9: warning: function 'register_shrinker' might be a
  candidate for 'gnu_printf' format attribute [-Wsuggest-attribute=format]
mm/vmscan.c:702:9: warning: function 'register_shrinker' might be a
  candidate for 'gnu_printf' format attribute [-Wsuggest-attribute=format]

Signed-off-by: Roman Gushchin <rom...@li...v>
---
 include/linux/shrinker.h | 14 ++++++++------
 1 file changed, 8 insertions(+), 6 deletions(-)

diff --git a/include/linux/shrinker.h b/include/linux/shrinker.h
index 64416f3e0a1f..08e6054e061f 100644
--- a/include/linux/shrinker.h
+++ b/include/linux/shrinker.h
@@ -93,9 +93,11 @@ struct shrinker {
  */
 #define SHRINKER_NONSLAB	(1 << 3)
 
-extern int prealloc_shrinker(struct shrinker *shrinker, const char *fmt, ...);
+extern int __printf(2, 3) prealloc_shrinker(struct shrinker *shrinker,
+					    const char *fmt, ...);
 extern void register_shrinker_prepared(struct shrinker *shrinker);
-extern int register_shrinker(struct shrinker *shrinker, const char *fmt, ...);
+extern int __printf(2, 3) register_shrinker(struct shrinker *shrinker,
+					    const char *fmt, ...);
 extern void unregister_shrinker(struct shrinker *shrinker);
 extern void free_prealloced_shrinker(struct shrinker *shrinker);
 extern void synchronize_shrinkers(void);
@@ -103,8 +105,8 @@ extern void synchronize_shrinkers(void);
 #ifdef CONFIG_SHRINKER_DEBUG
 extern int shrinker_debugfs_add(struct shrinker *shrinker);
 extern void shrinker_debugfs_remove(struct shrinker *shrinker);
-extern int shrinker_debugfs_rename(struct shrinker *shrinker,
-				   const char *fmt, ...);
+extern int __printf(2, 3) shrinker_debugfs_rename(struct shrinker *shrinker,
+						  const char *fmt, ...);
 #else /* CONFIG_SHRINKER_DEBUG */
 static inline int shrinker_debugfs_add(struct shrinker *shrinker)
 {
@@ -113,8 +115,8 @@ static inline int shrinker_debugfs_add(struct shrinker *shrinker)
 static inline void shrinker_debugfs_remove(struct shrinker *shrinker)
 {
 }
-static inline int shrinker_debugfs_rename(struct shrinker *shrinker,
-					  const char *fmt, ...)
+static inline __printf(2, 3)
+int shrinker_debugfs_rename(struct shrinker *shrinker, const char *fmt, ...)
 {
 	return 0;
 }
-- 
2.36.1