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@xxxxxxxxxxxxx>
Acked-by: Vlastimil Babka <vbabka@xxxxxxx>
---
v2: OR return values per Vlastimil, applied his Ack
v1: https://lore.kernel.org/linux-mm/20200930112612.76109-1-farman@xxxxxxxxxxxxx/T/#t
---
mm/slub.c | 6 +-----
1 file changed, 1 insertion(+), 5 deletions(-)
diff --git a/mm/slub.c b/mm/slub.c
index d4177aecedf6..6d3574013b2f 100644
--- a/mm/slub.c
+++ b/mm/slub.c
@@ -1413,10 +1413,6 @@ slab_flags_t kmem_cache_flags(unsigned int object_size,
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 */
@@ -1450,7 +1446,7 @@ slab_flags_t kmem_cache_flags(unsigned int object_size,
}
}
- return slub_debug;
+ return flags | slub_debug;
}
#else /* !CONFIG_SLUB_DEBUG */
static inline void setup_object_debug(struct kmem_cache *s,
--
2.17.1
