Duplicate slab cache names can create havoc for userspace tooling that expects slab cache names to be unique. This is a reasonable expectation. Sadly, too many duplicate name problems are out there in the wild, so simply pr_warn instead of pr_err() + failing the sanity check. Link: https://lore.kernel.org/linux-fsdevel/2d1d053da1cafb3e7940c4f25952da4f0af34e38.1722293276.git.osandov@xxxxxx/ Signed-off-by: Pedro Falcato <pedro.falcato@xxxxxxxxx> --- v2: - Replace the pr_err() + failure with a simple pr_warn Contrary to Vlastimil's suggestion, we don't seem to require a refcount == 0 check, because shutdown_cache already synchronously deletes the cache from the list (even reusing the same list_head for TYPESAFE_BY_RCU). mm/slab_common.c | 18 ++++++++++++++++++ 1 file changed, 18 insertions(+) diff --git a/mm/slab_common.c b/mm/slab_common.c index 40b582a014b..1abe6a577d5 100644 --- a/mm/slab_common.c +++ b/mm/slab_common.c @@ -88,6 +88,19 @@ unsigned int kmem_cache_size(struct kmem_cache *s) EXPORT_SYMBOL(kmem_cache_size); #ifdef CONFIG_DEBUG_VM + +static bool kmem_cache_is_duplicate_name(const char *name) +{ + struct kmem_cache *s; + + list_for_each_entry(s, &slab_caches, list) { + if (!strcmp(s->name, name)) + return true; + } + + return false; +} + static int kmem_cache_sanity_check(const char *name, unsigned int size) { if (!name || in_interrupt() || size > KMALLOC_MAX_SIZE) { @@ -95,6 +108,11 @@ static int kmem_cache_sanity_check(const char *name, unsigned int size) return -EINVAL; } + if (kmem_cache_is_duplicate_name(name)) { + /* Duplicate names will confuse slabtop, et al */ + pr_warn("%s: name %s already exists as a cache\n", __func__, name); + } + WARN_ON(strchr(name, ' ')); /* It confuses parsers */ return 0; } -- 2.46.0
