On Fri, Mar 02, 2018 at 08:44:27PM +0100, Andrey Konovalov wrote: > The krealloc function checks where the same buffer was reused or a new one > allocated by comparing kernel pointers. KHWASAN changes memory tag on the > krealloc'ed chunk of memory and therefore also changes the pointer tag of > the returned pointer. Therefore we need to perform comparison on untagged > (with tags reset) pointers to check whether it's the same memory region or > not. > --- > mm/slab_common.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/mm/slab_common.c b/mm/slab_common.c > index a33e61315ca6..7c829cbda1a5 100644 > --- a/mm/slab_common.c > +++ b/mm/slab_common.c > @@ -1494,7 +1494,7 @@ void *krealloc(const void *p, size_t new_size, gfp_t flags) > } > > ret = __do_krealloc(p, new_size, flags); > - if (ret && p != ret) > + if (ret && khwasan_reset_tag((void *)p) != khwasan_reset_tag(ret)) Why doesn't khwasan_reset_tag() take a const void *, like khwasan_set_tag() does? That way, this cast wouldn't be necessary. Thanks, Mark. -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>
