From patchwork Tue Nov 24 15:50:33 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Will Deacon X-Patchwork-Id: 11929271 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-17.0 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id AFFBCC2D0E4 for ; Tue, 24 Nov 2020 15:52:39 +0000 (UTC) Received: from merlin.infradead.org (merlin.infradead.org [205.233.59.134]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 35243206F7 for ; Tue, 24 Nov 2020 15:52:39 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="mIVJWgnB"; dkim=fail reason="signature verification failed" (1024-bit key) header.d=kernel.org header.i=@kernel.org header.b="CHScSSwS" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 35243206F7 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=kernel.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=merlin.20170209; h=Sender:Content-Transfer-Encoding: Content-Type:Cc:List-Subscribe:List-Help:List-Post:List-Archive: List-Unsubscribe:List-Id:MIME-Version:References:In-Reply-To:Message-Id:Date: Subject:To:From:Reply-To:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=7EvJ8AWk49M+D3ERo99gExES9uiB0FCe2q25EMpt/pc=; b=mIVJWgnBqvf2zDS+fIGo0rqMk 4l8fofi7gYG/hpa9j/3kjJQ8O+YKbKlhDjfNnPKVlKrPYST7M5dM9ik9MD9pX+Wu/yluxQwPBMVN4 1EWvyq/uSZsURHHXlnX5t0M2ZcCOwTHZeeFINKF3GSDfzHaZnVHPr4mO98c/5LLe1a91xOGjqguvm O5+IvS1yZzuez6l/JLfuDxtOa5lY/5aAkWQx9g7fuZDFNwtSosFyLhohqj+ufeY4uDaIL7/87I/ft 52XhVPEfSIn4gS3NTIGXqqbG9baYwehTg0UUKet1iG7HPdlUyF1f5PtTCR9FyToPSj7MtSDT7BpcX JnercgTVg==; Received: from localhost ([::1] helo=merlin.infradead.org) by merlin.infradead.org with esmtp (Exim 4.92.3 #3 (Red Hat Linux)) id 1khabl-0005G2-8I; Tue, 24 Nov 2020 15:51:57 +0000 Received: from mail.kernel.org ([198.145.29.99]) by merlin.infradead.org with esmtps (Exim 4.92.3 #3 (Red Hat Linux)) id 1khabC-00050z-F9 for linux-arm-kernel@lists.infradead.org; Tue, 24 Nov 2020 15:51:24 +0000 Received: from localhost.localdomain (236.31.169.217.in-addr.arpa [217.169.31.236]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 6B7DF206F7; Tue, 24 Nov 2020 15:51:17 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1606233081; bh=IhklJrTc98DlHw/NyV/h2FIqQqwEhiczqa0G/8pyr58=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=CHScSSwSemAKbOAQx6v20ZhR5errvNkNA+8HyRcRf9iVWL/9OgE46NIL5zwd+7MSg uNrVsM99EO2F2A5lQWBNWnpLX4kggtQCJSJv+kYUYRunhGHkS2AlNnD1upNtoCD/Hm aRN0Fs1QmvsTYGnPiEutGKaY4lwpHMQIVrqPS7rQ= From: Will Deacon To: linux-arm-kernel@lists.infradead.org Subject: [PATCH v4 08/14] arm64: exec: Adjust affinity for compat tasks with mismatched 32-bit EL0 Date: Tue, 24 Nov 2020 15:50:33 +0000 Message-Id: <20201124155039.13804-9-will@kernel.org> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20201124155039.13804-1-will@kernel.org> References: <20201124155039.13804-1-will@kernel.org> MIME-Version: 1.0 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20201124_105122_731424_01AD6309 X-CRM114-Status: GOOD ( 21.30 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: linux-arch@vger.kernel.org, Marc Zyngier , kernel-team@android.com, Vincent Guittot , Juri Lelli , Quentin Perret , Peter Zijlstra , Catalin Marinas , Johannes Weiner , linux-kernel@vger.kernel.org, Qais Yousef , Suren Baghdasaryan , Ingo Molnar , Li Zefan , Greg Kroah-Hartman , Tejun Heo , Will Deacon , Morten Rasmussen Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org When exec'ing a 32-bit task on a system with mismatched support for 32-bit EL0, try to ensure that it starts life on a CPU that can actually run it. Signed-off-by: Will Deacon Reviewed-by: Quentin Perret --- arch/arm64/kernel/process.c | 42 ++++++++++++++++++++++++++++++++++++- 1 file changed, 41 insertions(+), 1 deletion(-) diff --git a/arch/arm64/kernel/process.c b/arch/arm64/kernel/process.c index 1540ab0fbf23..72116b0c7c73 100644 --- a/arch/arm64/kernel/process.c +++ b/arch/arm64/kernel/process.c @@ -31,6 +31,7 @@ #include #include #include +#include #include #include #include @@ -625,6 +626,45 @@ unsigned long arch_align_stack(unsigned long sp) return sp & ~0xf; } +static void adjust_compat_task_affinity(struct task_struct *p) +{ + cpumask_var_t cpuset_mask; + const struct cpumask *possible_mask = system_32bit_el0_cpumask(); + const struct cpumask *newmask = possible_mask; + + /* + * Restrict the CPU affinity mask for a 32-bit task so that it contains + * only the 32-bit-capable subset of its original CPU mask. If this is + * empty, then try again with the cpuset allowed mask. If that fails, + * forcefully override it with the set of all 32-bit-capable CPUs that + * we know about. + * + * From the perspective of the task, this looks similar to what would + * happen if the 64-bit-only CPUs were hot-unplugged at the point of + * execve(). + */ + if (!restrict_cpus_allowed_ptr(p, possible_mask)) + goto out; + + if (alloc_cpumask_var(&cpuset_mask, GFP_KERNEL)) { + cpuset_cpus_allowed(p, cpuset_mask); + if (cpumask_and(cpuset_mask, cpuset_mask, possible_mask)) { + newmask = cpuset_mask; + goto out_set_mask; + } + } + + if (printk_ratelimit()) { + printk_deferred("Overriding affinity for 32-bit process %d (%s) to CPUs %*pbl\n", + task_pid_nr(p), p->comm, cpumask_pr_args(newmask)); + } +out_set_mask: + set_cpus_allowed_ptr(p, newmask); + free_cpumask_var(cpuset_mask); +out: + set_tsk_thread_flag(current, TIF_NOTIFY_RESUME); +} + /* * Called from setup_new_exec() after (COMPAT_)SET_PERSONALITY. */ @@ -635,7 +675,7 @@ void arch_setup_new_exec(void) if (is_compat_task()) { mmflags = MMCF_AARCH32; if (static_branch_unlikely(&arm64_mismatched_32bit_el0)) - set_tsk_thread_flag(current, TIF_NOTIFY_RESUME); + adjust_compat_task_affinity(current); } current->mm->context.flags = mmflags;