The patch titled
Subject: kasan, page_alloc: move tag_clear_highpage out of kernel_init_free_pages
has been added to the -mm tree. Its filename is
kasan-page_alloc-move-tag_clear_highpage-out-of-kernel_init_free_pages.patch
This patch should soon appear at
https://ozlabs.org/~akpm/mmots/broken-out/kasan-page_alloc-move-tag_clear_highpage-out-of-kernel_init_free_pages.patch
and later at
https://ozlabs.org/~akpm/mmotm/broken-out/kasan-page_alloc-move-tag_clear_highpage-out-of-kernel_init_free_pages.patch
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------------------------------------------------------
From: Andrey Konovalov <andreyknvl@xxxxxxxxxx>
Subject: kasan, page_alloc: move tag_clear_highpage out of kernel_init_free_pages
Currently, kernel_init_free_pages() serves two purposes: it either only
zeroes memory or zeroes both memory and memory tags via a different code
path. As this function has only two callers, each using only one code
path, this behaviour is confusing.
Pull the code that zeroes both memory and tags out of
kernel_init_free_pages().
As a result of this change, the code in free_pages_prepare() starts to
look complicated, but this is improved in the few following patches.
Those improvements are not integrated into this patch to make diffs easier
to read.
This patch does no functional changes.
Link: https://lkml.kernel.org/r/7719874e68b23902629c7cf19f966c4fd5f57979.1643047180.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 | 24 +++++++++++++-----------
1 file changed, 13 insertions(+), 11 deletions(-)
--- a/mm/page_alloc.c~kasan-page_alloc-move-tag_clear_highpage-out-of-kernel_init_free_pages
+++ a/mm/page_alloc.c
@@ -1282,16 +1282,10 @@ static inline bool should_skip_kasan_poi
PageSkipKASanPoison(page);
}
-static void kernel_init_free_pages(struct page *page, int numpages, bool zero_tags)
+static void kernel_init_free_pages(struct page *page, int numpages)
{
int i;
- if (zero_tags) {
- for (i = 0; i < numpages; i++)
- tag_clear_highpage(page + i);
- return;
- }
-
/* s390's use of memset() could override KASAN redzones. */
kasan_disable_current();
for (i = 0; i < numpages; i++) {
@@ -1387,7 +1381,7 @@ static __always_inline bool free_pages_p
bool init = want_init_on_free();
if (init)
- kernel_init_free_pages(page, 1 << order, false);
+ kernel_init_free_pages(page, 1 << order);
if (!skip_kasan_poison)
kasan_poison_pages(page, order, init);
}
@@ -2430,9 +2424,17 @@ inline void post_alloc_hook(struct page
bool init = !want_init_on_free() && want_init_on_alloc(gfp_flags);
kasan_unpoison_pages(page, order, init);
- if (init)
- kernel_init_free_pages(page, 1 << order,
- gfp_flags & __GFP_ZEROTAGS);
+
+ 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);
+ }
+ }
}
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
