From 9294b1281d0a212ef775a175b98ce71e6ac27b90 Mon Sep 17 00:00:00 2001 From: Andrey Konovalov Date: Thu, 24 Mar 2022 18:10:34 -0700 Subject: [PATCH] kasan, page_alloc: combine tag_clear_highpage calls in post_alloc_hook Move tag_clear_highpage() loops out of the kasan_has_integrated_init() clause as a code simplification. This patch does no functional changes. Link: https://lkml.kernel.org/r/587e3fc36358b88049320a89cc8dc6deaecb0cda.1643047180.git.andreyknvl@google.com Signed-off-by: Andrey Konovalov Reviewed-by: Alexander Potapenko Acked-by: Marco Elver Cc: Andrey Ryabinin Cc: Catalin Marinas Cc: Dmitry Vyukov Cc: Evgenii Stepanov Cc: Mark Rutland Cc: Peter Collingbourne Cc: Vincenzo Frascino Cc: Will Deacon Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- mm/page_alloc.c | 32 ++++++++++++++++---------------- 1 file changed, 16 insertions(+), 16 deletions(-) diff --git a/mm/page_alloc.c b/mm/page_alloc.c index db82fac..9d14ec3 100644 --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -2367,30 +2367,30 @@ inline void post_alloc_hook(struct page *page, unsigned int order, * KASAN unpoisoning and memory initializion code must be * kept together to avoid discrepancies in behavior. */ + + /* + * If memory tags should be zeroed (which happens only when memory + * should be initialized as well). + */ + if (init_tags) { + int i; + + /* Initialize both memory and tags. */ + for (i = 0; i != 1 << order; ++i) + tag_clear_highpage(page + i); + + /* Note that memory is already initialized by the loop above. */ + init = false; + } if (kasan_has_integrated_init()) { if (gfp_flags & __GFP_SKIP_KASAN_POISON) SetPageSkipKASanPoison(page); - if (init_tags) { - int i; - - for (i = 0; i != 1 << order; ++i) - tag_clear_highpage(page + i); - } else { + if (!init_tags) kasan_unpoison_pages(page, order, init); - } } else { kasan_unpoison_pages(page, order, init); - if (init_tags) { - int i; - - for (i = 0; i < 1 << order; i++) - tag_clear_highpage(page + i); - - init = false; - } - if (init) kernel_init_free_pages(page, 1 << order); } -- 2.7.4