From: Eric Farman <farman@linux.ibm.com>
Date: Fri, 2 Oct 2020 22:21:41 -0700
Subject: mm, slub: restore initial kmem_cache flags
Git-commit: 484cfaca95925f1a38ded6d0561de06a70409a32
Patch-mainline: v5.9-rc8
References: mm/slub bsc#1165692
The routine that applies debug flags to the kmem_cache slabs
inadvertantly prevents non-debug flags from being applied to those
same objects. That is, if slub_debug=<flag>,<slab> is specified,
non-debugged slabs will end up having flags of zero, and the slabs
may be unusable.
Fix this by including the input flags for non-matching slabs with the
contents of slub_debug, so that the caches are created as expected
alongside any debugging options that may be requested. With this, we
can remove the check for a NULL slub_debug_string, since it's covered
by the loop itself.
Fixes: e17f1dfba37b ("mm, slub: extend slub_debug syntax for multiple blocks")
Signed-off-by: Eric Farman <farman@linux.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Kees Cook <keescook@chromium.org>
Cc: Christoph Lameter <cl@linux.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: David Rientjes <rientjes@google.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Link: https://lkml.kernel.org/r/20200930161931.28575-1-farman@linux.ibm.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
---
mm/slub.c | 6 +-----
1 file changed, 1 insertion(+), 5 deletions(-)
--- a/mm/slub.c
+++ b/mm/slub.c
@@ -1381,10 +1381,6 @@ slab_flags_t kmem_cache_flags(unsigned i
char *next_block;
slab_flags_t block_flags;
- /* If slub_debug = 0, it folds into the if conditional. */
- if (!slub_debug_string)
- return flags | slub_debug;
-
len = strlen(name);
next_block = slub_debug_string;
/* Go through all blocks of debug options, see if any matches our slab's name */
@@ -1418,7 +1414,7 @@ slab_flags_t kmem_cache_flags(unsigned i
}
}
- return slub_debug;
+ return flags | slub_debug;
}
#else /* !CONFIG_SLUB_DEBUG */
static inline void setup_object_debug(struct kmem_cache *s,