From 9e7ee421ac1f8d7fe350d2dee87e31919e9cba84 Mon Sep 17 00:00:00 2001 From: Linus Walleij <linus.walleij@linaro.org> Date: Thu, 30 Jun 2022 10:41:22 +0200 Subject: [PATCH] mm: kfence: pass a pointer to virt_to_page() 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. Link: https://lkml.kernel.org/r/20220630084124.691207-4-linus.walleij@linaro.org Signed-off-by: Linus Walleij <linus.walleij@linaro.org> Reviewed-by: Marco Elver <elver@google.com> Cc: Alexander Potapenko <glider@google.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Jason Gunthorpe <jgg@nvidia.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> --- 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 4b5e5a3d3a638..d39ffb0583548 100644 --- a/mm/kfence/core.c +++ b/mm/kfence/core.c @@ -546,7 +546,7 @@ 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 @@ -660,7 +660,7 @@ 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 -- GitLab