From patchwork Mon Jan 24 18:02:10 2022 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: 12722749 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 bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 9E611C433EF for ; Mon, 24 Jan 2022 18:33:33 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:MIME-Version:References:In-Reply-To: Message-Id:Date:Subject:Cc:To:From:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=JWowsTRzvQLgpolqR2kHJ+gQXhiMMXojLx9Nw0QJRvQ=; b=VSAqY615S5IrAc okzHOp82RMFuDZvcTiH4mHGOY8viwFs7Nuw1tMMPdF0OoxVABIn6R6oYbhLt9PR44AXjH7A+FQP3g 2DtgGoyfy8ZKV8XhuDPJS9tlX339TL5Q6pdnr+2RQN4iXPlqEMi5CImMq0G9P+e5NgX6xsot1/NNM MsgttknATna5v/BPH8BIL1KmOTweM8XuNDSP8lNGtl4quH+1EcMEukIRaoAp47W+rSTMU5s01JU9T IuDf7e+jyX4V7C10DUt7pvVKFdHY7zoGQ/AqfLppO7ZheQkj7w8LxpWnPkjSB+6w14Cjdr4pWVMW3 HwtSAmo4qadxO4C4mESQ==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1nC48J-004WvD-Ju; Mon, 24 Jan 2022 18:32:04 +0000 Received: from out0.migadu.com ([2001:41d0:2:267::]) by bombadil.infradead.org with esmtps (Exim 4.94.2 #2 (Red Hat Linux)) id 1nC3gF-004LjS-1N for linux-arm-kernel@lists.infradead.org; Mon, 24 Jan 2022 18:03:07 +0000 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=1643047375; 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=NtjC8GJtWhPCzF1O+E8r8kpeY3QxluInaVM8vIRb3RM=; b=bKBbSy6fPym/MRrA09RJIXkFlYKAWKOMZ3FKz5LNI3x7DUkJ4ipRMk3eZQPDdGKQEIJ+Rn j3caDMhxpDJoFvlu8+abP1Q+12iYW+9yQZ9ALHbERTjD13CazkPOVr1esNMbanQHMt1ZYL /Tgi6BMH04tWMfhdG1YeU09jhv3m/Vc= From: andrey.konovalov@linux.dev To: Andrew Morton Cc: Andrey Konovalov , Marco Elver , Alexander Potapenko , 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 v6 02/39] kasan, page_alloc: move tag_clear_highpage out of kernel_init_free_pages Date: Mon, 24 Jan 2022 19:02:10 +0100 Message-Id: <7719874e68b23902629c7cf19f966c4fd5f57979.1643047180.git.andreyknvl@google.com> In-Reply-To: References: MIME-Version: 1.0 X-Migadu-Flow: FLOW_OUT X-Migadu-Auth-User: linux.dev X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20220124_100303_476583_32B62854 X-CRM114-Status: GOOD ( 15.20 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org 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. 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. Signed-off-by: Andrey Konovalov Reviewed-by: Alexander Potapenko --- Changes v2->v3: - Update patch description. --- 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 25d4f9ad3525..012170b1c47a 100644 --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -1282,16 +1282,10 @@ 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++) { @@ -1387,7 +1381,7 @@ 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); } @@ -2430,9 +2424,17 @@ 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);