From 4c39529663b93165953ecf9b1a9ea817358dcd06 Mon Sep 17 00:00:00 2001 From: Pedro Falcato Date: Wed, 7 Aug 2024 10:07:46 +0100 Subject: slab: Warn on duplicate cache names when DEBUG_VM=y Duplicate slab cache names can create havoc for userspace tooling that expects slab cache names to be unique [1]. This is a reasonable expectation. Sadly, too many duplicate name problems are out there in the wild, so simply warn instead of pr_err() + failing the sanity check. [ vbabka@suse.cz: change to WARN_ON(), see the discussion at [2] ] Link: https://lore.kernel.org/linux-fsdevel/2d1d053da1cafb3e7940c4f25952da4f0af34e38.1722293276.git.osandov@fb.com/ [1] Link: https://lore.kernel.org/all/20240807090746.2146479-1-pedro.falcato@gmail.com/ [2] Signed-off-by: Pedro Falcato Acked-by: Christoph Lameter Signed-off-by: Vlastimil Babka --- mm/slab_common.c | 17 +++++++++++++++++ 1 file changed, 17 insertions(+) (limited to 'mm/slab_common.c') diff --git a/mm/slab_common.c b/mm/slab_common.c index 40b582a014b8..dea2b05c0e3f 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 +108,10 @@ static int kmem_cache_sanity_check(const char *name, unsigned int size) return -EINVAL; } + /* Duplicate names will confuse slabtop, et al */ + WARN(kmem_cache_is_duplicate_name(name), + "kmem_cache of name '%s' already exists\n", name); + WARN_ON(strchr(name, ' ')); /* It confuses parsers */ return 0; } -- cgit v1.2.3