From 01d92c7f358ce892279ca830cf6ccf2862a17d1c Mon Sep 17 00:00:00 2001 From: Andrey Konovalov Date: Thu, 24 Mar 2022 18:11:16 -0700 Subject: kasan, vmalloc, arm64: mark vmalloc mappings as pgprot_tagged HW_TAGS KASAN relies on ARM Memory Tagging Extension (MTE). With MTE, a memory region must be mapped as MT_NORMAL_TAGGED to allow setting memory tags via MTE-specific instructions. Add proper protection bits to vmalloc() allocations. These allocations are always backed by page_alloc pages, so the tags will actually be getting set on the corresponding physical memory. Link: https://lkml.kernel.org/r/983fc33542db2f6b1e77b34ca23448d4640bbb9e.1643047180.git.andreyknvl@google.com Signed-off-by: Andrey Konovalov Co-developed-by: Vincenzo Frascino Signed-off-by: Vincenzo Frascino Acked-by: Marco Elver Cc: Alexander Potapenko Cc: Andrey Ryabinin Cc: Catalin Marinas Cc: Dmitry Vyukov Cc: Evgenii Stepanov Cc: Mark Rutland Cc: Peter Collingbourne Cc: Will Deacon Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- mm/vmalloc.c | 9 +++++++++ 1 file changed, 9 insertions(+) (limited to 'mm/vmalloc.c') diff --git a/mm/vmalloc.c b/mm/vmalloc.c index 1ab1f1b2f5b7..8530d86c3e58 100644 --- a/mm/vmalloc.c +++ b/mm/vmalloc.c @@ -3128,6 +3128,15 @@ again: goto fail; } + /* + * Modify protection bits to allow tagging. + * This must be done before mapping by __vmalloc_area_node(). + */ + if (kasan_hw_tags_enabled() && + pgprot_val(prot) == pgprot_val(PAGE_KERNEL)) + prot = arch_vmap_pgprot_tagged(prot); + + /* Allocate physical pages and map them into vmalloc space. */ addr = __vmalloc_area_node(area, gfp_mask, prot, shift, node); if (!addr) goto fail; -- cgit v1.2.3