From mboxrd@z Thu Jan 1 00:00:00 1970 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 D5AA1C54E76 for ; Sun, 19 Nov 2023 16:59:48 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 703E46B03A1; Sun, 19 Nov 2023 11:59:48 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 6A79E6B03A3; Sun, 19 Nov 2023 11:59:48 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 571A96B03A4; Sun, 19 Nov 2023 11:59:48 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0016.hostedemail.com [216.40.44.16]) by kanga.kvack.org (Postfix) with ESMTP id 45D6D6B03A1 for ; Sun, 19 Nov 2023 11:59:48 -0500 (EST) Received: from smtpin21.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay08.hostedemail.com (Postfix) with ESMTP id 2389314033B for ; Sun, 19 Nov 2023 16:59:48 +0000 (UTC) X-FDA: 81475315656.21.DC282F4 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by imf26.hostedemail.com (Postfix) with ESMTP id 84410140010 for ; Sun, 19 Nov 2023 16:59:46 +0000 (UTC) Authentication-Results: imf26.hostedemail.com; dkim=none; spf=pass (imf26.hostedemail.com: domain of alexandru.elisei@arm.com designates 217.140.110.172 as permitted sender) smtp.mailfrom=alexandru.elisei@arm.com; dmarc=pass (policy=none) header.from=arm.com ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1700413186; a=rsa-sha256; cv=none; b=mm+KUa1feQJQH7k32fcMVCppnQ2q8qdMP318wSIWhUZ3vSSRyJmn1S8N2faUlMxFW1YRxN 8Cpe75jI63CYp/ChfouxVuTZkXXNcLp/Em56GIcnPM0IRqRIMkRB7ENiynGz8qytrJbzqS yd/yKEgGLs2oIFeKoYFmFZG5mtFRZAY= ARC-Authentication-Results: i=1; imf26.hostedemail.com; dkim=none; spf=pass (imf26.hostedemail.com: domain of alexandru.elisei@arm.com designates 217.140.110.172 as permitted sender) smtp.mailfrom=alexandru.elisei@arm.com; dmarc=pass (policy=none) header.from=arm.com ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1700413186; h=from:from:sender:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=5VJSuOR5nwPM4kRlFje7nh/AMUnlivOQlbnl38/y3r0=; b=gNuhU3nKHw2cOsrlIMCO8mIGx6rTSTIYi7EsdTO1NMaxI9CVTuwBDhDL3pz9WtAww8+vrq 3fID0c2DQzwv8cKje9oxan3NDPLv2IrQETab15rwopjHw+l6GLhgNH/lPVjZ2ts17S9XPk ejyLgogBuUaJLmp0gdhpz3Nt8UyHA2g= Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 2B3AD14BF; Sun, 19 Nov 2023 09:00:32 -0800 (PST) Received: from e121798.cable.virginm.net (unknown [172.31.20.19]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 00E483F6C4; Sun, 19 Nov 2023 08:59:40 -0800 (PST) From: Alexandru Elisei To: catalin.marinas@arm.com, will@kernel.org, oliver.upton@linux.dev, maz@kernel.org, james.morse@arm.com, suzuki.poulose@arm.com, yuzenghui@huawei.com, arnd@arndb.de, akpm@linux-foundation.org, mingo@redhat.com, peterz@infradead.org, juri.lelli@redhat.com, vincent.guittot@linaro.org, dietmar.eggemann@arm.com, rostedt@goodmis.org, bsegall@google.com, mgorman@suse.de, bristot@redhat.com, vschneid@redhat.com, mhiramat@kernel.org, rppt@kernel.org, hughd@google.com Cc: pcc@google.com, steven.price@arm.com, anshuman.khandual@arm.com, vincenzo.frascino@arm.com, david@redhat.com, eugenis@google.com, kcc@google.com, hyesoo.yu@samsung.com, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, kvmarm@lists.linux.dev, linux-fsdevel@vger.kernel.org, linux-arch@vger.kernel.org, linux-mm@kvack.org, linux-trace-kernel@vger.kernel.org Subject: [PATCH RFC v2 24/27] arm64: mte: Handle fatal signal in reserve_tag_storage() Date: Sun, 19 Nov 2023 16:57:18 +0000 Message-Id: <20231119165721.9849-25-alexandru.elisei@arm.com> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20231119165721.9849-1-alexandru.elisei@arm.com> References: <20231119165721.9849-1-alexandru.elisei@arm.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Rspam-User: X-Rspamd-Server: rspam06 X-Rspamd-Queue-Id: 84410140010 X-Stat-Signature: q9t8kztoynha9gjhkjzkfeuimy4ichkw X-HE-Tag: 1700413186-855956 X-HE-Meta: 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 BiebT83H HzCrZN6ZNujUhCYLSWB46gmmTGeZl16049frJOFNd52pugRmPwUF3dwK4AkzZGBnDGLSoleclw7m1QBLLMIjQHZSgqZ200Bt2apAljDyi8nZRBosAt9x1DmCpkol6e83vYHpoKai5K/xTz650Wtk4O3XwAuRY85MVuzTC+eiucRyQq1pr3RqKEHfLZKeAsPzhjXmbihkn7Ty7ASSBMHUSZBLP9w== 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: List-Subscribe: List-Unsubscribe: As long as a fatal signal is pending, alloc_contig_range() will fail with -EINTR. This makes it impossible for tag storage allocation to succeed, and the page allocator will print an OOM splat. The process is going to be killed, so return 0 (success) from reserve_tag_storage() to allow the page allocator to make progress. set_pte_at() will map it with PAGE_FAULT_ON_ACCESS and subsequent accesses from different threads will cause a fault until the signal is delivered. Signed-off-by: Alexandru Elisei --- arch/arm64/kernel/mte_tag_storage.c | 17 +++++++++++++++++ arch/arm64/mm/fault.c | 5 +++++ 2 files changed, 22 insertions(+) diff --git a/arch/arm64/kernel/mte_tag_storage.c b/arch/arm64/kernel/mte_tag_storage.c index 6b11bb408b51..602fdc70db1c 100644 --- a/arch/arm64/kernel/mte_tag_storage.c +++ b/arch/arm64/kernel/mte_tag_storage.c @@ -572,6 +572,23 @@ int reserve_tag_storage(struct page *page, int order, gfp_t gfp) break; } + /* + * alloc_contig_range() returns -EINTR from + * __alloc_contig_migrate_range() if a fatal signal is pending. + * As long as the signal hasn't been handled, it is impossible + * to reserve tag storage for any page. Stop trying to reserve + * tag storage, but return 0 so the page allocator can make + * forward progress, instead of printing an OOM splat. + * + * The tagged page with missing tag storage will be mapped with + * PAGE_FAULT_ON_ACCESS in set_pte_at(), which means accesses + * until the signal is delivered will cause a fault. + */ + if (ret == -EINTR) { + ret = 0; + goto out_error; + } + if (ret) goto out_error; diff --git a/arch/arm64/mm/fault.c b/arch/arm64/mm/fault.c index 964c5ae161a3..fdc98c5828bf 100644 --- a/arch/arm64/mm/fault.c +++ b/arch/arm64/mm/fault.c @@ -950,6 +950,11 @@ gfp_t arch_calc_vma_gfp(struct vm_area_struct *vma, gfp_t gfp) void tag_clear_highpage(struct page *page) { + if (tag_storage_enabled() && unlikely(!page_tag_storage_reserved(page))) { + clear_page(page_address(page)); + return; + } + /* Newly allocated page, shouldn't have been tagged yet */ WARN_ON_ONCE(!try_page_mte_tagging(page)); mte_zero_clear_page_tags(page_address(page)); -- 2.42.1