From patchwork Mon Dec 13 21:51:20 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: andrey.konovalov@linux.dev X-Patchwork-Id: 12674629 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by smtp.lore.kernel.org (Postfix) with ESMTP id C3127C433EF for ; Mon, 13 Dec 2021 21:52:55 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 9B5096B0074; Mon, 13 Dec 2021 16:52:15 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 963806B0075; Mon, 13 Dec 2021 16:52:15 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 804CC6B0078; Mon, 13 Dec 2021 16:52:15 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0240.hostedemail.com [216.40.44.240]) by kanga.kvack.org (Postfix) with ESMTP id 72FA16B0074 for ; Mon, 13 Dec 2021 16:52:15 -0500 (EST) Received: from smtpin14.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay03.hostedemail.com (Postfix) with ESMTP id 2D8C882499B9 for ; Mon, 13 Dec 2021 21:52:05 +0000 (UTC) X-FDA: 78914119410.14.20058ED Received: from out2.migadu.com (out2.migadu.com [188.165.223.204]) by imf16.hostedemail.com (Postfix) with ESMTP id 94D86180007 for ; Mon, 13 Dec 2021 21:52:04 +0000 (UTC) X-Report-Abuse: Please report any abuse attempt to abuse@migadu.com and include these headers. DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.dev; s=key1; t=1639432323; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=HTPWk4VEgIiC15H1k53BSSNevm2/MKWkVZ7PL0Pz+og=; b=pO2y9wB96F+fpIxzOrZMGtpyaag8jAce/tp1qKAQvQi+v2sp/GxpPdyClZ3ocrVnuIvpDp gV5lRKj/X4XS6IXYQCiAhoc/uKcPLO40xTSMrD0clnpxkIwiXFWAXNmpoikMTZi0ofOhBH txnprvPfdXEB2ZsqFt0bPCRzaiHh67s= From: andrey.konovalov@linux.dev To: Marco Elver , Alexander Potapenko , Andrew Morton Cc: Andrey Konovalov , Dmitry Vyukov , Andrey Ryabinin , kasan-dev@googlegroups.com, linux-mm@kvack.org, Vincenzo Frascino , Catalin Marinas , Will Deacon , Mark Rutland , linux-arm-kernel@lists.infradead.org, Peter Collingbourne , Evgenii Stepanov , linux-kernel@vger.kernel.org, Andrey Konovalov Subject: [PATCH mm v3 01/38] kasan, page_alloc: deduplicate should_skip_kasan_poison Date: Mon, 13 Dec 2021 22:51:20 +0100 Message-Id: <3423b7a9e4ba814fc77df37267a3f7911490b1db.1639432170.git.andreyknvl@google.com> In-Reply-To: References: MIME-Version: 1.0 X-Migadu-Flow: FLOW_OUT X-Migadu-Auth-User: andrey.konovalov@linux.dev Authentication-Results: imf16.hostedemail.com; dkim=pass header.d=linux.dev header.s=key1 header.b=pO2y9wB9; dmarc=pass (policy=none) header.from=linux.dev; spf=pass (imf16.hostedemail.com: domain of andrey.konovalov@linux.dev designates 188.165.223.204 as permitted sender) smtp.mailfrom=andrey.konovalov@linux.dev X-Rspamd-Server: rspam08 X-Rspamd-Queue-Id: 94D86180007 X-Stat-Signature: ojzxtp7azwjpbokdwby4y7rxrwy5yz3h X-HE-Tag: 1639432324-112569 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: From: Andrey Konovalov Currently, should_skip_kasan_poison() has two definitions: one for when CONFIG_DEFERRED_STRUCT_PAGE_INIT is enabled, one for when it's not. Instead of duplicating the checks, add a deferred_pages_enabled() helper and use it in a single should_skip_kasan_poison() definition. Also move should_skip_kasan_poison() closer to its caller and clarify all conditions in the comment. Signed-off-by: Andrey Konovalov --- Changes v2->v3: - Update patch description. --- mm/page_alloc.c | 55 +++++++++++++++++++++++++++++-------------------- 1 file changed, 33 insertions(+), 22 deletions(-) diff --git a/mm/page_alloc.c b/mm/page_alloc.c index edfd6c81af82..f0bcecac19cd 100644 --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -377,25 +377,9 @@ int page_group_by_mobility_disabled __read_mostly; */ static DEFINE_STATIC_KEY_TRUE(deferred_pages); -/* - * Calling kasan_poison_pages() only after deferred memory initialization - * has completed. Poisoning pages during deferred memory init will greatly - * lengthen the process and cause problem in large memory systems as the - * deferred pages initialization is done with interrupt disabled. - * - * Assuming that there will be no reference to those newly initialized - * pages before they are ever allocated, this should have no effect on - * KASAN memory tracking as the poison will be properly inserted at page - * allocation time. The only corner case is when pages are allocated by - * on-demand allocation and then freed again before the deferred pages - * initialization is done, but this is not likely to happen. - */ -static inline bool should_skip_kasan_poison(struct page *page, fpi_t fpi_flags) +static inline bool deferred_pages_enabled(void) { - return static_branch_unlikely(&deferred_pages) || - (!IS_ENABLED(CONFIG_KASAN_GENERIC) && - (fpi_flags & FPI_SKIP_KASAN_POISON)) || - PageSkipKASanPoison(page); + return static_branch_unlikely(&deferred_pages); } /* Returns true if the struct page for the pfn is uninitialised */ @@ -446,11 +430,9 @@ defer_init(int nid, unsigned long pfn, unsigned long end_pfn) return false; } #else -static inline bool should_skip_kasan_poison(struct page *page, fpi_t fpi_flags) +static inline bool deferred_pages_enabled(void) { - return (!IS_ENABLED(CONFIG_KASAN_GENERIC) && - (fpi_flags & FPI_SKIP_KASAN_POISON)) || - PageSkipKASanPoison(page); + return false; } static inline bool early_page_uninitialised(unsigned long pfn) @@ -1270,6 +1252,35 @@ static int free_tail_pages_check(struct page *head_page, struct page *page) return ret; } +/* + * Skip KASAN memory poisoning when either: + * + * 1. Deferred memory initialization has not yet completed, + * see the explanation below. + * 2. Skipping poisoning is requested via FPI_SKIP_KASAN_POISON, + * see the comment next to it. + * 3. Skipping poisoning is requested via __GFP_SKIP_KASAN_POISON, + * see the comment next to it. + * + * Poisoning pages during deferred memory init will greatly lengthen the + * process and cause problem in large memory systems as the deferred pages + * initialization is done with interrupt disabled. + * + * Assuming that there will be no reference to those newly initialized + * pages before they are ever allocated, this should have no effect on + * KASAN memory tracking as the poison will be properly inserted at page + * allocation time. The only corner case is when pages are allocated by + * on-demand allocation and then freed again before the deferred pages + * initialization is done, but this is not likely to happen. + */ +static inline bool should_skip_kasan_poison(struct page *page, fpi_t fpi_flags) +{ + return deferred_pages_enabled() || + (!IS_ENABLED(CONFIG_KASAN_GENERIC) && + (fpi_flags & FPI_SKIP_KASAN_POISON)) || + PageSkipKASanPoison(page); +} + static void kernel_init_free_pages(struct page *page, int numpages, bool zero_tags) { int i;