From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-pf1-f173.google.com (mail-pf1-f173.google.com [209.85.210.173]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 0CB7213D8A3 for ; Thu, 8 Aug 2024 17:35:03 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.210.173 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1723138505; cv=none; b=TGGXmOoOI3TjhEqxUZl2Muo9RFjc5z3SKUHy4NjCGiPO5zV0KsXELqUP1u/XpUSMPwPuIBgKewJ8wL9R4AZYB8xXShSSg8e64QHEj8wC5QWZgylzPwP4vHoYnx+3LHJzazj/+RzsCcZQggkKpvYX7NojPoRmsU1//0eWzn4lkaY= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1723138505; c=relaxed/simple; bh=8KYFidw8hrpQOyjPQf5i8Ok/To5dJrpwoNzBWE2dnNU=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=a4e6TZBB1TEP/m6vgw4hUjUK44gi/PNkrabeOFDXi5Hk8ezyhv6iZgxgfIU+RNtRuiQFAopSIYGL6u7H5FCgXbu+NqodpjcDdmA4nDy+5m34dUiC81KSMeqcIlj2tx/ciSpDmwqDOXBgtWhUe9UWDGP+Fdm1DCyiGm23fjcPHqg= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=gmail.com; spf=pass smtp.mailfrom=gmail.com; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b=Bn0+rqgC; arc=none smtp.client-ip=209.85.210.173 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=gmail.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=gmail.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="Bn0+rqgC" Received: by mail-pf1-f173.google.com with SMTP id d2e1a72fcca58-70d2b921cdfso1083743b3a.0 for ; Thu, 08 Aug 2024 10:35:03 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20230601; t=1723138503; x=1723743303; darn=vger.kernel.org; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:from:to:cc:subject:date:message-id:reply-to; bh=diwD1iCrpHXumZkgAMloBVGIf2kIwgitsF/BakIzCjE=; b=Bn0+rqgCrMjEC+RMKKvyCzH4PHQGUyZ+wYJk0phqp5F/LCqb5sh1lJ015wdfC+uKi2 90HLohzrpRN2TvHuky40PylAIppOScgsjI3uJ6G5OOpD5AU7Dh3v6A34yImKR0S1tDFu /HvsqogoBMmewykzdAbmoJZZZvXC71pOBhu7B/9g3CSNHvhaqbrZ3HyIVRkpbLY9ktfu hKJXFkGjYDO39MCzmp/C9q6CrrAoqZUIL+X/Fp1iAEf8dXk6tqpnI3h3fYv6DJoo6oPP Ce8rfYmTfalQd7t7m7iwDyq4UHTbq2Oadv7Rs/sCaRxc9nNRe+jfCQdb60v77uMbR58+ ilew== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1723138503; x=1723743303; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:x-gm-message-state:from:to:cc:subject:date :message-id:reply-to; bh=diwD1iCrpHXumZkgAMloBVGIf2kIwgitsF/BakIzCjE=; b=dMJrAChD9Vu3cB4GNpsDT1Ycihzi8KhAF38Xwb4vOneqU8BChXn0M1hoAxTp+MCbO1 7BaZbD7Da6cXQxUJD024JdKZHdkgrjTZqflVMB8wjtNlKEdMgJUdFdke0A5J8U7J6Uu3 JelxOQhg30UWLn9rUmGShEAXLAccvBYU6+1p4kVnowd5SWJrZrthKNlJsaGJ/Hs55WFR tgSQl9wevCfzBWvCjrUka4kTUznWNJyBFXihmQXHTrJd5hMsr5DzjZOyS7ZVDoIsUsvO 1aMQrN0B1EQ76FNQZpxUZcZYOSKa7ylvYwaLmEIjIfx51sQOsAzVL0RDY6K656cbAVFm jmhQ== X-Forwarded-Encrypted: i=1; AJvYcCWc8nKhAVA+lpN1y6iKmegGxFlhvVDn4ZEK4ZavuEX1yrUM0gXuAP+NjnELNrve7WP58KCuKTHHj3vqWSLg2graopswQj0msmtIFGWU X-Gm-Message-State: AOJu0YyRefHFjA829kw8Z5NXy63YceWZ+vdeU4H88KCYGcZ52vpRTd07 qLODIBx3ET0Zw+8Ot9uWPw5FAkG47nevE9p/n8pEetWqGPKsGUxT X-Google-Smtp-Source: AGHT+IE51YiR1kStYj12rpo+NUS09VqpSsVkvxnS3g7oMwKAgam1hLO0cnWbZ/U3GDmrQEv657ePjA== X-Received: by 2002:a05:6a00:2d95:b0:70b:cf1:8dc9 with SMTP id d2e1a72fcca58-710cae7174bmr3204310b3a.25.1723138503114; Thu, 08 Aug 2024 10:35:03 -0700 (PDT) Received: from localhost ([216.228.127.130]) by smtp.gmail.com with ESMTPSA id d2e1a72fcca58-710cb22f29asm1363716b3a.63.2024.08.08.10.35.01 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 08 Aug 2024 10:35:02 -0700 (PDT) Date: Thu, 8 Aug 2024 10:35:00 -0700 From: Yury Norov To: Gavin Shan Cc: linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, linux@rasmusvillemoes.dk, Jonathan.Cameron@huawei.com, salil.mehta@huawei.com, shan.gavin@gmail.com Subject: Re: [PATCH] cpumask: Fix crash on updating CPU enabled mask Message-ID: References: <20240808040808.647316-1-gshan@redhat.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20240808040808.647316-1-gshan@redhat.com> On Thu, Aug 08, 2024 at 02:08:08PM +1000, Gavin Shan wrote: > The CPU enabled mask instead of the CPU possible mask should be used > by set_cpu_enabled(). Otherwise, we run into crash due to write to > the read-only CPU possible mask when vCPU is hot added on ARM64. > > (qemu) device_add host-arm-cpu,id=cpu1,socket-id=1 > Unable to handle kernel write to read-only memory at virtual address ffff800080fa7190 > : > Call trace: > register_cpu+0x1a4/0x2e8 > arch_register_cpu+0x84/0xd8 > acpi_processor_add+0x480/0x5b0 > acpi_bus_attach+0x1c4/0x300 > acpi_dev_for_one_check+0x3c/0x50 > device_for_each_child+0x68/0xc8 > acpi_dev_for_each_child+0x48/0x80 > acpi_bus_attach+0x84/0x300 > acpi_bus_scan+0x74/0x220 > acpi_scan_rescan_bus+0x54/0x88 > acpi_device_hotplug+0x208/0x478 > acpi_hotplug_work_fn+0x2c/0x50 > process_one_work+0x15c/0x3c0 > worker_thread+0x2ec/0x400 > kthread+0x120/0x130 > ret_from_fork+0x10/0x20 > > Fix it by passing the CPU enabled mask instead of the CPU possible > mask to set_cpu_enabled(). > > Fixes: 51c4767503d5 ("Merge tag 'bitmap-6.11-rc1' of https://github.com:/norov/linux") > Signed-off-by: Gavin Shan > --- > include/linux/cpumask.h | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/include/linux/cpumask.h b/include/linux/cpumask.h > index 801a7e524113..53158de44b83 100644 > --- a/include/linux/cpumask.h > +++ b/include/linux/cpumask.h > @@ -1037,7 +1037,7 @@ void init_cpu_online(const struct cpumask *src); > assign_bit(cpumask_check(cpu), cpumask_bits(mask), (val)) > > #define set_cpu_possible(cpu, possible) assign_cpu((cpu), &__cpu_possible_mask, (possible)) > -#define set_cpu_enabled(cpu, enabled) assign_cpu((cpu), &__cpu_possible_mask, (enabled)) > +#define set_cpu_enabled(cpu, enabled) assign_cpu((cpu), &__cpu_enabled_mask, (enabled)) > #define set_cpu_present(cpu, present) assign_cpu((cpu), &__cpu_present_mask, (present)) > #define set_cpu_active(cpu, active) assign_cpu((cpu), &__cpu_active_mask, (active)) > #define set_cpu_dying(cpu, dying) assign_cpu((cpu), &__cpu_dying_mask, (dying)) > -- > 2.45.2 Thanks Gavin. I'll send a pull request withing this week. Thanks, Yury