On 7/25/24 2:54 PM, Danilo Krummrich wrote: > Document that concurrent calls to vrealloc() with itself or vfree() for > the same memory allocation are not permitted, since it leads to undefined > behavior. > > Consequently, the same applies for kvrealloc(), hence also document it > for kvrealloc(). > > Suggested-by: Christoph Hellwig <hch@xxxxxxxxxxxxx> > Suggested-by: Uladzislau Rezki <urezki@xxxxxxxxx> > Signed-off-by: Danilo Krummrich <dakr@xxxxxxxxxx> Huh, did anyone ever assume otherwise and why? > --- > mm/util.c | 3 +++ > mm/vmalloc.c | 3 +++ > 2 files changed, 6 insertions(+) > > diff --git a/mm/util.c b/mm/util.c > index 0ff5898cc6de..29ae93f6344f 100644 > --- a/mm/util.c > +++ b/mm/util.c > @@ -732,6 +732,9 @@ EXPORT_SYMBOL(kvfree_sensitive); > * If @p is %NULL, kvrealloc() behaves exactly like kvmalloc(). If @size is 0 > * and @p is not a %NULL pointer, the object pointed to is freed. > * > + * This function must not be called concurrently with itself or kvfree() for the > + * same memory allocation. > + * > * Return: pointer to the allocated memory or %NULL in case of error > */ > void *kvrealloc_noprof(const void *p, size_t size, gfp_t flags) > diff --git a/mm/vmalloc.c b/mm/vmalloc.c > index caf032f0bd69..2a6d4ce57b73 100644 > --- a/mm/vmalloc.c > +++ b/mm/vmalloc.c > @@ -4049,6 +4049,9 @@ EXPORT_SYMBOL(vzalloc_node_noprof); > * If @p is %NULL, vrealloc() behaves exactly like vmalloc(). If @size is 0 and > * @p is not a %NULL pointer, the object pointed to is freed. > * > + * This function must not be called concurrently with itself or vfree() for the > + * same memory allocation. > + * > * Return: pointer to the allocated memory; %NULL if @size is zero or in case of > * failure > */ > > base-commit: d270beaca6818349b2aed7e6034b800a777087cc
