The patch titled Subject: kasan, page_alloc: refactor init checks in post_alloc_hook has been added to the -mm tree. Its filename is kasan-page_alloc-refactor-init-checks-in-post_alloc_hook.patch This patch should soon appear at https://ozlabs.org/~akpm/mmots/broken-out/kasan-page_alloc-refactor-init-checks-in-post_alloc_hook.patch and later at https://ozlabs.org/~akpm/mmotm/broken-out/kasan-page_alloc-refactor-init-checks-in-post_alloc_hook.patch Before you just go and hit "reply", please: a) Consider who else should be cc'ed b) Prefer to cc a suitable mailing list as well c) Ideally: find the original patch on the mailing list and do a reply-to-all to that, adding suitable additional cc's *** Remember to use Documentation/process/submit-checklist.rst when testing your code *** The -mm tree is included into linux-next and is updated there every 3-4 working days ------------------------------------------------------ From: Andrey Konovalov <andreyknvl@xxxxxxxxxx> Subject: 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@xxxxxxxxxx Signed-off-by: Andrey Konovalov <andreyknvl@xxxxxxxxxx> Reviewed-by: Alexander Potapenko <glider@xxxxxxxxxx> Acked-by: Marco Elver <elver@xxxxxxxxxx> Cc: Andrey Ryabinin <ryabinin.a.a@xxxxxxxxx> Cc: Catalin Marinas <catalin.marinas@xxxxxxx> Cc: Dmitry Vyukov <dvyukov@xxxxxxxxxx> Cc: Evgenii Stepanov <eugenis@xxxxxxxxxx> Cc: Mark Rutland <mark.rutland@xxxxxxx> Cc: Peter Collingbourne <pcc@xxxxxxxxxx> Cc: Vincenzo Frascino <vincenzo.frascino@xxxxxxx> Cc: Will Deacon <will@xxxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- mm/page_alloc.c | 20 +++++++++++--------- 1 file changed, 11 insertions(+), 9 deletions(-) --- a/mm/page_alloc.c~kasan-page_alloc-refactor-init-checks-in-post_alloc_hook +++ a/mm/page_alloc.c @@ -2420,19 +2420,21 @@ inline void post_alloc_hook(struct page 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) { - int i; - - for (i = 0; i < 1 << order; i++) - tag_clear_highpage(page + i); - } else { - kernel_init_free_pages(page, 1 << order); - } + 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); } set_page_owner(page, order, gfp_flags); _ Patches currently in -mm which might be from andreyknvl@xxxxxxxxxx are kasan-page_alloc-deduplicate-should_skip_kasan_poison.patch kasan-page_alloc-move-tag_clear_highpage-out-of-kernel_init_free_pages.patch kasan-page_alloc-merge-kasan_free_pages-into-free_pages_prepare.patch kasan-page_alloc-simplify-kasan_poison_pages-call-site.patch kasan-page_alloc-init-memory-of-skipped-pages-on-free.patch kasan-drop-skip_kasan_poison-variable-in-free_pages_prepare.patch mm-clarify-__gfp_zerotags-comment.patch kasan-only-apply-__gfp_zerotags-when-memory-is-zeroed.patch kasan-page_alloc-refactor-init-checks-in-post_alloc_hook.patch kasan-page_alloc-merge-kasan_alloc_pages-into-post_alloc_hook.patch kasan-page_alloc-combine-tag_clear_highpage-calls-in-post_alloc_hook.patch kasan-page_alloc-move-setpageskipkasanpoison-in-post_alloc_hook.patch kasan-page_alloc-move-kernel_init_free_pages-in-post_alloc_hook.patch kasan-page_alloc-rework-kasan_unpoison_pages-call-site.patch kasan-clean-up-metadata-byte-definitions.patch kasan-define-kasan_vmalloc_invalid-for-sw_tags.patch kasan-x86-arm64-s390-rename-functions-for-modules-shadow.patch kasan-vmalloc-drop-outdated-vm_kasan-comment.patch kasan-reorder-vmalloc-hooks.patch kasan-add-wrappers-for-vmalloc-hooks.patch kasan-vmalloc-reset-tags-in-vmalloc-functions.patch kasan-fork-reset-pointer-tags-of-vmapped-stacks.patch kasan-arm64-reset-pointer-tags-of-vmapped-stacks.patch kasan-vmalloc-add-vmalloc-tagging-for-sw_tags.patch kasan-vmalloc-arm64-mark-vmalloc-mappings-as-pgprot_tagged.patch kasan-vmalloc-unpoison-vm_alloc-pages-after-mapping.patch kasan-mm-only-define-___gfp_skip_kasan_poison-with-hw_tags.patch kasan-page_alloc-allow-skipping-unpoisoning-for-hw_tags.patch kasan-page_alloc-allow-skipping-memory-init-for-hw_tags.patch kasan-vmalloc-add-vmalloc-tagging-for-hw_tags.patch kasan-vmalloc-only-tag-normal-vmalloc-allocations.patch kasan-arm64-dont-tag-executable-vmalloc-allocations.patch kasan-mark-kasan_arg_stacktrace-as-__initdata.patch kasan-clean-up-feature-flags-for-hw_tags-mode.patch kasan-add-kasanvmalloc-command-line-flag.patch kasan-allow-enabling-kasan_vmalloc-and-sw-hw_tags.patch arm64-select-kasan_vmalloc-for-sw-hw_tags-modes.patch kasan-documentation-updates.patch kasan-improve-vmalloc-tests.patch