From: Vlastimil Babka vbabka@suse.cz
[ Upstream commit 4b183dd9359d5772446cb634b12a383bed98c4fc ]
slab_err() has variadic printf arguments but instead of passing them to slab_bug() it does vsnprintf() to a buffer and passes %s, buf.
To allow passing them directly, turn slab_bug() to __slab_bug() with a va_list parameter, and slab_bug() a wrapper with fmt, ... parameters. Then slab_err() can call __slab_bug() without the intermediate buffer.
Also constify fmt everywhere, which also simplifies object_err()'s call to slab_bug().
Signed-off-by: Vlastimil Babka vbabka@suse.cz Reviewed-by: Harry Yoo harry.yoo@oracle.com Stable-dep-of: b4efccec8d06 ("mm/slub: avoid accessing metadata when pointer is invalid in object_err()") Signed-off-by: Sasha Levin sashal@kernel.org --- mm/slub.c | 28 ++++++++++++++++++---------- 1 file changed, 18 insertions(+), 10 deletions(-)
diff --git a/mm/slub.c b/mm/slub.c index f6323fac6a026..39fb2b930fdf7 100644 --- a/mm/slub.c +++ b/mm/slub.c @@ -1027,12 +1027,12 @@ void skip_orig_size_check(struct kmem_cache *s, const void *object) set_orig_size(s, (void *)object, s->object_size); }
-static void slab_bug(struct kmem_cache *s, char *fmt, ...) +static void __slab_bug(struct kmem_cache *s, const char *fmt, va_list argsp) { struct va_format vaf; va_list args;
- va_start(args, fmt); + va_copy(args, argsp); vaf.fmt = fmt; vaf.va = &args; pr_err("=============================================================================\n"); @@ -1041,8 +1041,17 @@ static void slab_bug(struct kmem_cache *s, char *fmt, ...) va_end(args); }
+static void slab_bug(struct kmem_cache *s, const char *fmt, ...) +{ + va_list args; + + va_start(args, fmt); + __slab_bug(s, fmt, args); + va_end(args); +} + __printf(2, 3) -static void slab_fix(struct kmem_cache *s, char *fmt, ...) +static void slab_fix(struct kmem_cache *s, const char *fmt, ...) { struct va_format vaf; va_list args; @@ -1098,12 +1107,12 @@ static void print_trailer(struct kmem_cache *s, struct slab *slab, u8 *p) }
static void object_err(struct kmem_cache *s, struct slab *slab, - u8 *object, char *reason) + u8 *object, const char *reason) { if (slab_add_kunit_errors()) return;
- slab_bug(s, "%s", reason); + slab_bug(s, reason); print_trailer(s, slab, object); add_taint(TAINT_BAD_PAGE, LOCKDEP_NOW_UNRELIABLE);
@@ -1139,15 +1148,14 @@ static __printf(3, 4) void slab_err(struct kmem_cache *s, struct slab *slab, const char *fmt, ...) { va_list args; - char buf[100];
if (slab_add_kunit_errors()) return;
va_start(args, fmt); - vsnprintf(buf, sizeof(buf), fmt, args); + __slab_bug(s, fmt, args); va_end(args); - slab_bug(s, "%s", buf); + __slab_err(slab); }
@@ -1185,7 +1193,7 @@ static void init_object(struct kmem_cache *s, void *object, u8 val) s->inuse - poison_size); }
-static void restore_bytes(struct kmem_cache *s, char *message, u8 data, +static void restore_bytes(struct kmem_cache *s, const char *message, u8 data, void *from, void *to) { slab_fix(s, "Restoring %s 0x%p-0x%p=0x%x", message, from, to - 1, data); @@ -1200,7 +1208,7 @@ static void restore_bytes(struct kmem_cache *s, char *message, u8 data,
static pad_check_attributes int check_bytes_and_report(struct kmem_cache *s, struct slab *slab, - u8 *object, char *what, u8 *start, unsigned int value, + u8 *object, const char *what, u8 *start, unsigned int value, unsigned int bytes, bool slab_obj_print) { u8 *fault;