diff options
| author | Uladzislau Rezki (Sony) <urezki@gmail.com> | 2026-04-28 18:14:18 +0200 |
|---|---|---|
| committer | Herbert Xu <herbert@gondor.apana.org.au> | 2026-05-05 16:12:07 +0800 |
| commit | dad0d91cc2c3e6b6fb285ccfe7ddf71525797198 (patch) | |
| tree | c79f99c2bea8980aa044feab8bf3baedb7c3619a | |
| parent | 09ae540e1d5c02210795911bf5459282d7af04e9 (diff) | |
mm/slab: Add kvfree_atomic() helper
kvmalloc() now supports non-sleeping GFP flags, including
the vmalloc fallback path. This means it may return vmalloc
memory even for GFP_ATOMIC and GFP_NOWAIT allocations.
Freeing such memory with kvfree() may then end up calling
vfree(), which is not safe for non-sleeping contexts.
Introduce kvfree_atomic() helper for such cases. It mirrors
kvfree(), but uses vfree_atomic() for vmalloced memory.
Signed-off-by: Uladzislau Rezki (Sony) <urezki@gmail.com>
Acked-by: Vlastimil Babka (SUSE) <vbabka@kernel.org>
Acked-by: Harry Yoo (Oracle) <harry@kernel.org>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
| -rw-r--r-- | include/linux/slab.h | 3 | ||||
| -rw-r--r-- | mm/slub.c | 16 |
2 files changed, 19 insertions, 0 deletions
diff --git a/include/linux/slab.h b/include/linux/slab.h index 15a60b501b95..2b5ab488e96b 100644 --- a/include/linux/slab.h +++ b/include/linux/slab.h @@ -1234,6 +1234,9 @@ void *kvrealloc_node_align_noprof(const void *p, size_t size, unsigned long alig extern void kvfree(const void *addr); DEFINE_FREE(kvfree, void *, if (!IS_ERR_OR_NULL(_T)) kvfree(_T)) +extern void kvfree_atomic(const void *addr); +DEFINE_FREE(kvfree_atomic, void *, if (!IS_ERR_OR_NULL(_T)) kvfree_atomic(_T)) + extern void kvfree_sensitive(const void *addr, size_t len); unsigned int kmem_cache_size(struct kmem_cache *s); diff --git a/mm/slub.c b/mm/slub.c index 0baa906f39ab..8f9004536729 100644 --- a/mm/slub.c +++ b/mm/slub.c @@ -6883,6 +6883,22 @@ void kvfree(const void *addr) EXPORT_SYMBOL(kvfree); /** + * kvfree_atomic() - Free memory. + * @addr: Pointer to allocated memory. + * + * Same as kvfree(), but uses vfree_atomic() for vmalloc + * backed memory. Must not be called from NMI context. + */ +void kvfree_atomic(const void *addr) +{ + if (is_vmalloc_addr(addr)) + vfree_atomic(addr); + else + kfree(addr); +} +EXPORT_SYMBOL(kvfree_atomic); + +/** * kvfree_sensitive - Free a data object containing sensitive information. * @addr: address of the data object to be freed. * @len: length of the data object. |