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authorAndrey Konovalov <andreyknvl@google.com>2022-03-25 02:10:43 +0100
committerLinus Torvalds <torvalds@linux-foundation.org>2022-03-25 03:06:46 +0100
commite9d0ca9228162f5442b751edf8c9721b15dcfa1e (patch)
tree953a159a1d96cfa643f95c5e672cacd1c4533bdb /mm/page_alloc.c
parentkasan, page_alloc: move kernel_init_free_pages in post_alloc_hook (diff)
downloadlinux-e9d0ca9228162f5442b751edf8c9721b15dcfa1e.tar.xz
linux-e9d0ca9228162f5442b751edf8c9721b15dcfa1e.zip
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@google.com Signed-off-by: Andrey Konovalov <andreyknvl@google.com> Acked-by: Marco Elver <elver@google.com> Cc: Alexander Potapenko <glider@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>
Diffstat (limited to '')
-rw-r--r--mm/page_alloc.c19
1 files changed, 12 insertions, 7 deletions
diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index 386898f1a7c3..350bb27dc4bb 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -2382,15 +2382,20 @@ inline void post_alloc_hook(struct page *page, unsigned int order,
/* 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)