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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) --- include/linux/slab.h | 3 +++ mm/slub.c | 16 ++++++++++++++++ 2 files changed, 19 insertions(+) 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 2b2d33cc735c..b096677c8152 100644 --- a/mm/slub.c +++ b/mm/slub.c @@ -6802,6 +6802,22 @@ 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. -- 2.47.3