The patch titled Subject: kasan, page_alloc: rework kasan_unpoison_pages call site has been added to the -mm tree. Its filename is kasan-page_alloc-rework-kasan_unpoison_pages-call-site.patch This patch should soon appear at https://ozlabs.org/~akpm/mmots/broken-out/kasan-page_alloc-rework-kasan_unpoison_pages-call-site.patch and later at https://ozlabs.org/~akpm/mmotm/broken-out/kasan-page_alloc-rework-kasan_unpoison_pages-call-site.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: rework kasan_unpoison_pages call site Rework the checks around kasan_unpoison_pages() call in post_alloc_hook(). The logical condition for calling this function is: - If a software KASAN mode is enabled, we need to mark shadow memory. - Otherwise, HW_TAGS KASAN is enabled, and it only makes sense to set tags if they haven't already been cleared by tag_clear_highpage(), which is indicated by init_tags. This patch concludes the changes for post_alloc_hook(). Link: https://lkml.kernel.org/r/0ecebd0d7ccd79150e3620ea4185a32d3dfe912f.1643047180.git.andreyknvl@xxxxxxxxxx Signed-off-by: Andrey Konovalov <andreyknvl@xxxxxxxxxx> Acked-by: Marco Elver <elver@xxxxxxxxxx> Cc: Alexander Potapenko <glider@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 | 19 ++++++++++++------- 1 file changed, 12 insertions(+), 7 deletions(-) --- a/mm/page_alloc.c~kasan-page_alloc-rework-kasan_unpoison_pages-call-site +++ a/mm/page_alloc.c @@ -2434,15 +2434,20 @@ inline void post_alloc_hook(struct page /* Note that memory is already initialized by the loop above. */ init = false; } - if (kasan_has_integrated_init()) { - if (!init_tags) { - kasan_unpoison_pages(page, order, init); + /* + * If either a software KASAN mode is enabled, or, + * in the case of hardware tag-based KASAN, + * if memory tags have not been cleared via tag_clear_highpage(). + */ + if (IS_ENABLED(CONFIG_KASAN_GENERIC) || + IS_ENABLED(CONFIG_KASAN_SW_TAGS) || + kasan_hw_tags_enabled() && !init_tags) { + /* Mark shadow memory or set memory tags. */ + kasan_unpoison_pages(page, order, init); - /* Note that memory is already initialized by KASAN. */ + /* Note that memory is already initialized by KASAN. */ + if (kasan_has_integrated_init()) init = false; - } - } else { - kasan_unpoison_pages(page, order, init); } /* If memory is still not initialized, do it now. */ if (init) _ 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