Commit b8491b90 authored Mar 24, 2022 by Andrey Konovalov Committed by Linus Torvalds Mar 24, 2022

kasan, page_alloc: refactor init checks in post_alloc_hook

Separate code for zeroing memory from the code clearing tags in
post_alloc_hook().

This patch is not useful by itself but makes the simplifications in the
following patches easier to follow.

This patch does no functional changes.

Link: https://lkml.kernel.org/r/2283fde963adfd8a2b29a92066f106cc16661a3c.1643047180.git.andreyknvl@google.com


Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Reviewed-by: Alexander Potapenko <glider@google.com>
Acked-by: Marco Elver <elver@google.com>
Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Evgenii Stepanov <eugenis@google.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Peter Collingbourne <pcc@google.com>
Cc: Vincenzo Frascino <vincenzo.frascino@arm.com>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

parent 1c0e5b24

mm/page_alloc.c

+10 −8

Original line number	Diff line number	Diff line
		@@ -2368,19 +2368,21 @@ inline void post_alloc_hook(struct page *page, unsigned int order,
		kasan_alloc_pages(page, order, gfp_flags);
		} else {
		bool init = !want_init_on_free() && want_init_on_alloc(gfp_flags);
		bool init_tags = init && (gfp_flags & __GFP_ZEROTAGS);

		kasan_unpoison_pages(page, order, init);

		if (init) {
		if (gfp_flags & __GFP_ZEROTAGS) {
		if (init_tags) {
		int i;

		for (i = 0; i < 1 << order; i++)
		tag_clear_highpage(page + i);
		} else {
		kernel_init_free_pages(page, 1 << order);
		}

		init = false;
		}

		if (init)
		kernel_init_free_pages(page, 1 << order);
		}

		set_page_owner(page, order, gfp_flags);