From: Marco Elver <elver@google.com>
To: andrey.konovalov@linux.dev
Cc: Alexander Potapenko <glider@google.com>,
Vincenzo Frascino <vincenzo.frascino@arm.com>,
Catalin Marinas <catalin.marinas@arm.com>,
Peter Collingbourne <pcc@google.com>,
Andrey Konovalov <andreyknvl@gmail.com>,
Dmitry Vyukov <dvyukov@google.com>,
Andrey Ryabinin <aryabinin@virtuozzo.com>,
kasan-dev@googlegroups.com,
Andrew Morton <akpm@linux-foundation.org>,
linux-mm@kvack.org, Will Deacon <will@kernel.org>,
linux-arm-kernel@lists.infradead.org,
Evgenii Stepanov <eugenis@google.com>,
linux-kernel@vger.kernel.org,
Andrey Konovalov <andreyknvl@google.com>
Subject: Re: [PATCH 04/31] kasan, page_alloc: simplify kasan_poison_pages call site
Date: Wed, 1 Dec 2021 15:09:56 +0100 [thread overview]
Message-ID: <YaeCNIyblUAk5mmI@elver.google.com> (raw)
In-Reply-To: <b28f30ed5d662439fd2354b7a05e4d58a2889e5f.1638308023.git.andreyknvl@google.com>
On Tue, Nov 30, 2021 at 10:39PM +0100, andrey.konovalov@linux.dev wrote:
> From: Andrey Konovalov <andreyknvl@google.com>
>
> Simplify the code around calling kasan_poison_pages() in
> free_pages_prepare().
>
> Reording kasan_poison_pages() and kernel_init_free_pages() is OK,
> since kernel_init_free_pages() can handle poisoned memory.
Why did they have to be reordered?
> This patch does no functional changes besides reordering the calls.
>
> Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
> ---
> mm/page_alloc.c | 18 +++++-------------
> 1 file changed, 5 insertions(+), 13 deletions(-)
>
> diff --git a/mm/page_alloc.c b/mm/page_alloc.c
> index 3f3ea41f8c64..0673db27dd12 100644
> --- a/mm/page_alloc.c
> +++ b/mm/page_alloc.c
> @@ -1289,6 +1289,7 @@ static __always_inline bool free_pages_prepare(struct page *page,
> {
> int bad = 0;
> bool skip_kasan_poison = should_skip_kasan_poison(page, fpi_flags);
skip_kasan_poison is only used once now, so you could remove the
variable -- unless later code will use it in more than once place again.
> + bool init = want_init_on_free();
>
> VM_BUG_ON_PAGE(PageTail(page), page);
>
> @@ -1359,19 +1360,10 @@ static __always_inline bool free_pages_prepare(struct page *page,
> * With hardware tag-based KASAN, memory tags must be set before the
> * page becomes unavailable via debug_pagealloc or arch_free_page.
> */
> - if (kasan_has_integrated_init()) {
> - bool init = want_init_on_free();
> -
> - if (!skip_kasan_poison)
> - kasan_poison_pages(page, order, init);
> - } else {
> - bool init = want_init_on_free();
> -
> - if (init)
> - kernel_init_free_pages(page, 1 << order);
> - if (!skip_kasan_poison)
> - kasan_poison_pages(page, order, init);
> - }
> + if (!skip_kasan_poison)
> + kasan_poison_pages(page, order, init);
> + if (init && !kasan_has_integrated_init())
> + kernel_init_free_pages(page, 1 << order);
>
> /*
> * arch_free_page() can make the page's contents inaccessible. s390
> --
> 2.25.1
next prev parent reply other threads:[~2021-12-01 14:10 UTC|newest]
Thread overview: 56+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-11-30 21:39 [PATCH 00/31] kasan, vmalloc, arm64: add vmalloc tagging support for SW/HW_TAGS andrey.konovalov
2021-11-30 21:39 ` [PATCH 01/31] kasan, page_alloc: deduplicate should_skip_kasan_poison andrey.konovalov
2021-11-30 21:39 ` [PATCH 02/31] kasan, page_alloc: move tag_clear_highpage out of kernel_init_free_pages andrey.konovalov
2021-12-02 15:24 ` Alexander Potapenko
2021-11-30 21:39 ` [PATCH 03/31] kasan, page_alloc: merge kasan_free_pages into free_pages_prepare andrey.konovalov
2021-12-02 15:32 ` Alexander Potapenko
2021-11-30 21:39 ` [PATCH 04/31] kasan, page_alloc: simplify kasan_poison_pages call site andrey.konovalov
2021-12-01 14:09 ` Marco Elver [this message]
2021-12-06 21:07 ` Andrey Konovalov
2021-11-30 21:39 ` [PATCH 05/31] kasan, page_alloc: init memory of skipped pages on free andrey.konovalov
2021-11-30 21:41 ` [PATCH 06/31] mm: clarify __GFP_ZEROTAGS comment andrey.konovalov
2021-11-30 21:41 ` [PATCH 07/31] kasan: only apply __GFP_ZEROTAGS when memory is zeroed andrey.konovalov
2021-12-02 15:40 ` Alexander Potapenko
2021-11-30 21:41 ` [PATCH 08/31] kasan, page_alloc: refactor init checks in post_alloc_hook andrey.konovalov
2021-12-02 16:13 ` Alexander Potapenko
2021-12-06 21:09 ` Andrey Konovalov
2021-12-16 10:59 ` Alexander Potapenko
2021-11-30 21:42 ` [PATCH 09/31] kasan, page_alloc: merge kasan_alloc_pages into post_alloc_hook andrey.konovalov
2021-11-30 21:52 ` [PATCH 10/31] kasan, page_alloc: combine tag_clear_highpage calls in post_alloc_hook andrey.konovalov
2021-11-30 22:05 ` [PATCH 11/31] kasan, page_alloc: move SetPageSkipKASanPoison " andrey.konovalov
2021-11-30 22:05 ` [PATCH 12/31] kasan, page_alloc: move kernel_init_free_pages " andrey.konovalov
2021-11-30 22:05 ` [PATCH 13/31] kasan, page_alloc: simplify kasan_unpoison_pages call site andrey.konovalov
2021-11-30 22:06 ` [PATCH 14/31] kasan: clean up metadata byte definitions andrey.konovalov
2021-11-30 22:06 ` [PATCH 15/31] kasan: define KASAN_VMALLOC_INVALID for SW_TAGS andrey.konovalov
2021-11-30 22:06 ` [PATCH 16/31] kasan, x86, arm64, s390: rename functions for modules shadow andrey.konovalov
2021-11-30 22:06 ` [PATCH 17/31] kasan, vmalloc: drop outdated VM_KASAN comment andrey.konovalov
2021-11-30 22:07 ` [PATCH 18/31] kasan: reorder vmalloc hooks andrey.konovalov
2021-11-30 22:07 ` [PATCH 20/31] kasan, vmalloc: reset tags in vmalloc functions andrey.konovalov
2021-12-02 14:17 ` Marco Elver
2021-12-06 21:08 ` Andrey Konovalov
2021-11-30 22:07 ` [PATCH 19/31] kasan: add wrappers for vmalloc hooks andrey.konovalov
2021-11-30 22:07 ` [PATCH 21/31] kasan, fork: don't tag stacks allocated with vmalloc andrey.konovalov
2021-12-02 14:27 ` Marco Elver
2021-12-06 21:08 ` Andrey Konovalov
2021-11-30 22:07 ` [PATCH 22/31] kasan, vmalloc: add vmalloc support to SW_TAGS andrey.konovalov
2021-11-30 22:07 ` [PATCH 23/31] kasan, arm64: allow KASAN_VMALLOC with SW_TAGS andrey.konovalov
2021-12-03 12:37 ` Marco Elver
2021-12-06 21:10 ` Andrey Konovalov
2021-11-30 22:07 ` [PATCH 24/31] kasan, vmalloc, arm64: mark vmalloc mappings as pgprot_tagged andrey.konovalov
2021-12-03 12:42 ` Marco Elver
2021-12-06 21:12 ` Andrey Konovalov
2021-11-30 22:08 ` [PATCH 25/31] kasan, vmalloc: don't unpoison VM_ALLOC pages before mapping andrey.konovalov
2021-11-30 22:08 ` [PATCH 26/31] kasan, page_alloc: allow skipping unpoisoning for HW_TAGS andrey.konovalov
2021-11-30 22:08 ` [PATCH 27/31] kasan, vmalloc: add vmalloc support to HW_TAGS andrey.konovalov
2021-12-03 12:41 ` Marco Elver
2021-12-06 21:12 ` Andrey Konovalov
2021-11-30 22:08 ` [PATCH 28/31] kasan: add kasan.vmalloc command line flag andrey.konovalov
2021-12-03 12:09 ` Marco Elver
2021-12-06 21:09 ` Andrey Konovalov
2021-11-30 22:08 ` [PATCH 29/31] kasan, arm64: allow KASAN_VMALLOC with HW_TAGS andrey.konovalov
2021-12-01 11:35 ` Marco Elver
2021-12-06 21:10 ` Andrey Konovalov
2021-12-03 12:40 ` Marco Elver
2021-12-06 21:10 ` Andrey Konovalov
2021-11-30 22:08 ` [PATCH 30/31] kasan: documentation updates andrey.konovalov
2021-11-30 22:08 ` [PATCH 31/31] kasan: improve vmalloc tests andrey.konovalov
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