Functions that work on a pointer to virtual memory such as virt_to_pfn() and users of that function such as virt_to_page() are supposed to pass a pointer to virtual memory, ideally a (void *) or other pointer. However since many architectures implement virt_to_pfn() as a macro, this function becomes polymorphic and accepts both a (unsigned long) and a (void *). If we instead implement a proper virt_to_pfn(void *addr) function the following happens (occurred on arch/arm): mm/kfence/core.c:558:30: warning: passing argument 1 of 'virt_to_pfn' makes pointer from integer without a cast [-Wint-conversion] In one case we can refer to __kfence_pool directly (and that is a proper (char *) pointer) and in the other call site we use an explicit cast. Cc: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> Cc: Alexander Potapenko <glider@xxxxxxxxxx> Cc: Marco Elver <elver@xxxxxxxxxx> Cc: Dmitry Vyukov <dvyukov@xxxxxxxxxx> Cc: kasan-dev@xxxxxxxxxxxxxxxx Cc: linux-mm@xxxxxxxxx Signed-off-by: Linus Walleij <linus.walleij@xxxxxxxxxx> --- mm/kfence/core.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/mm/kfence/core.c b/mm/kfence/core.c index 4e7cd4c8e687..153cde62ad72 100644 --- a/mm/kfence/core.c +++ b/mm/kfence/core.c @@ -543,7 +543,7 @@ static unsigned long kfence_init_pool(void) if (!arch_kfence_init_pool()) return addr; - pages = virt_to_page(addr); + pages = virt_to_page(__kfence_pool); /* * Set up object pages: they must have PG_slab set, to avoid freeing @@ -657,7 +657,7 @@ static bool kfence_init_pool_late(void) /* Same as above. */ free_size = KFENCE_POOL_SIZE - (addr - (unsigned long)__kfence_pool); #ifdef CONFIG_CONTIG_ALLOC - free_contig_range(page_to_pfn(virt_to_page(addr)), free_size / PAGE_SIZE); + free_contig_range(page_to_pfn(virt_to_page((void *)addr)), free_size / PAGE_SIZE); #else free_pages_exact((void *)addr, free_size); #endif -- 2.36.1
