mm/slub.c: trace free objects at KERN_INFO

Currently when trace is enabled (e.g.  slub_debug=T,kmalloc-128 ) the
trace messages are mostly output at KERN_INFO.  However the trace code
also calls print_section() to hexdump the head of a free object.  This
is hard coded to use KERN_ERR, meaning the console is deluged with trace
messages even if we've asked for quiet.

Fix this the obvious way but adding a level parameter to
print_section(), allowing calls from the trace code to use the same
trace level as other trace messages.

Link: http://lkml.kernel.org/r/20170113154850.518-1-daniel.thompson@linaro.org
Signed-off-by: Daniel Thompson <daniel.thompson@linaro.org>
Acked-by: Christoph Lameter <cl@linux.com>
Acked-by: David Rientjes <rientjes@google.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 13 insertions, 10 deletions

diff --git a/mm/slub.c b/mm/slub.c
index 067598a00849..7aa6f433f4de 100644
--- a/mm/slub.c
+++ b/mm/slub.c
@@ -496,10 +496,11 @@ static inline int check_valid_pointer(struct kmem_cache *s,
         return 1;
 }
 
-static void print_section(char *text, u8 *addr, unsigned int length)
+static void print_section(char *level, char *text, u8 *addr,
+                          unsigned int length)
 {
         metadata_access_enable();
-        print_hex_dump(KERN_ERR, text, DUMP_PREFIX_ADDRESS, 16, 1, addr,
+        print_hex_dump(level, text, DUMP_PREFIX_ADDRESS, 16, 1, addr,
                         length, 1);
         metadata_access_disable();
 }
@@ -636,14 +637,15 @@ static void print_trailer(struct kmem_cache *s, struct page *page, u8 *p)
                p, p - addr, get_freepointer(s, p));
 
         if (s->flags & SLAB_RED_ZONE)
-                print_section("Redzone ", p - s->red_left_pad, s->red_left_pad);
+                print_section(KERN_ERR, "Redzone ", p - s->red_left_pad,
+                              s->red_left_pad);
         else if (p > addr + 16)
-                print_section("Bytes b4 ", p - 16, 16);
+                print_section(KERN_ERR, "Bytes b4 ", p - 16, 16);
 
-        print_section("Object ", p, min_t(unsigned long, s->object_size,
-                                PAGE_SIZE));
+        print_section(KERN_ERR, "Object ", p,
+                      min_t(unsigned long, s->object_size, PAGE_SIZE));
         if (s->flags & SLAB_RED_ZONE)
-                print_section("Redzone ", p + s->object_size,
+                print_section(KERN_ERR, "Redzone ", p + s->object_size,
                         s->inuse - s->object_size);
 
         if (s->offset)
@@ -658,7 +660,8 @@ static void print_trailer(struct kmem_cache *s, struct page *page, u8 *p)
 
         if (off != size_from_object(s))
                 /* Beginning of the filler is the free pointer */
-                print_section("Padding ", p + off, size_from_object(s) - off);
+                print_section(KERN_ERR, "Padding ", p + off,
+                              size_from_object(s) - off);
 
         dump_stack();
 }
@@ -820,7 +823,7 @@ static int slab_pad_check(struct kmem_cache *s, struct page *page)
                 end--;
 
         slab_err(s, page, "Padding overwritten. 0x%p-0x%p", fault, end - 1);
-        print_section("Padding ", end - remainder, remainder);
+        print_section(KERN_ERR, "Padding ", end - remainder, remainder);
 
         restore_bytes(s, "slab padding", POISON_INUSE, end - remainder, end);
         return 0;
@@ -973,7 +976,7 @@ static void trace(struct kmem_cache *s, struct page *page, void *object,
                         page->freelist);
 
                 if (!alloc)
-                        print_section("Object ", (void *)object,
+                        print_section(KERN_INFO, "Object ", (void *)object,
                                         s->object_size);
 
                 dump_stack();