From patchwork Mon Dec 6 21:31:07 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: 12659725 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 150EFC433F5 for ; Mon, 6 Dec 2021 21:32:08 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 7D3CF6B0072; Mon, 6 Dec 2021 16:31:57 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 75C386B0083; Mon, 6 Dec 2021 16:31:57 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 5D6956B0085; Mon, 6 Dec 2021 16:31:57 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0152.hostedemail.com [216.40.44.152]) by kanga.kvack.org (Postfix) with ESMTP id 4B3FD6B0072 for ; Mon, 6 Dec 2021 16:31:57 -0500 (EST) Received: from smtpin20.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay05.hostedemail.com (Postfix) with ESMTP id 142F3181B04B5 for ; Mon, 6 Dec 2021 21:31:47 +0000 (UTC) X-FDA: 78888666654.20.BC5027B Received: from out1.migadu.com (out1.migadu.com [91.121.223.63]) by imf07.hostedemail.com (Postfix) with ESMTP id 8746B10000A7 for ; Mon, 6 Dec 2021 21:31:46 +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=1638826304; 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=A+HW6k6OAcUIQ5pcvvYHE04liTPVazbrvXn/E55v5k4=; b=G8KjRNXo5Y05KabVgmRYMgc1kapn6FpN2ZKrG2QD5hDJGEDn7Tgi7gprNzRm620OoRUlWh fysL0arSZUir4OcxIwEJmUp1ixpSkbukKCOGx4X9E3Z8uoPUERQfMpDZ3RPzVpGLPrf91S UBLlmOt/Dw/nA9x6H4xAIem9Q/qthz0= From: andrey.konovalov@linux.dev To: Marco Elver , Alexander Potapenko , Vincenzo Frascino , Catalin Marinas , Peter Collingbourne Cc: Andrey Konovalov , Dmitry Vyukov , Andrey Ryabinin , kasan-dev@googlegroups.com, Andrew Morton , linux-mm@kvack.org, Will Deacon , Mark Rutland , linux-arm-kernel@lists.infradead.org, Evgenii Stepanov , linux-kernel@vger.kernel.org, Andrey Konovalov Subject: [PATCH v2 02/34] kasan, page_alloc: move tag_clear_highpage out of kernel_init_free_pages Date: Mon, 6 Dec 2021 22:31:07 +0100 Message-Id: <2ace94811bd1ce8c87519bf55bcc163c2a78d3cd.1638825394.git.andreyknvl@google.com> In-Reply-To: References: MIME-Version: 1.0 X-Migadu-Flow: FLOW_OUT X-Migadu-Auth-User: linux.dev X-Stat-Signature: 5dzsfufzox61nm8myytn88hbkjmre1jj Authentication-Results: imf07.hostedemail.com; dkim=pass header.d=linux.dev header.s=key1 header.b=G8KjRNXo; spf=pass (imf07.hostedemail.com: domain of andrey.konovalov@linux.dev designates 91.121.223.63 as permitted sender) smtp.mailfrom=andrey.konovalov@linux.dev; dmarc=pass (policy=none) header.from=linux.dev X-Rspamd-Server: rspam11 X-Rspamd-Queue-Id: 8746B10000A7 X-HE-Tag: 1638826306-400962 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, 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. This patch pulls 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. Signed-off-by: Andrey Konovalov Reviewed-by: Alexander Potapenko --- mm/page_alloc.c | 24 +++++++++++++----------- 1 file changed, 13 insertions(+), 11 deletions(-) diff --git a/mm/page_alloc.c b/mm/page_alloc.c index c99566a3b67e..3589333b5b77 100644 --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -1269,16 +1269,10 @@ static inline bool should_skip_kasan_poison(struct page *page, fpi_t fpi_flags) 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++) { @@ -1372,7 +1366,7 @@ static __always_inline bool free_pages_prepare(struct page *page, 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); } @@ -2415,9 +2409,17 @@ inline void post_alloc_hook(struct page *page, unsigned int order, 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);