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[209.132.183.28]) by mx.google.com with ESMTPS id j55si6817765qvc.209.2019.08.06.02.26.52 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Tue, 06 Aug 2019 02:26:53 -0700 (PDT) Received-SPF: pass (google.com: domain of david@redhat.com designates 209.132.183.28 as permitted sender) client-ip=209.132.183.28; Authentication-Results: mx.google.com; spf=pass (google.com: domain of david@redhat.com designates 209.132.183.28 as permitted sender) smtp.mailfrom=david@redhat.com; dmarc=pass (p=NONE sp=NONE dis=NONE) header.from=redhat.com Received: from smtp.corp.redhat.com (int-mx05.intmail.prod.int.phx2.redhat.com [10.5.11.15]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 23E24C008621; Tue, 6 Aug 2019 09:26:52 +0000 (UTC) Received: from [10.36.117.71] (ovpn-117-71.ams2.redhat.com [10.36.117.71]) by smtp.corp.redhat.com (Postfix) with ESMTP id 5E2705D704; Tue, 6 Aug 2019 09:26:50 +0000 (UTC) Subject: Re: [PATCH v1] driver/base/memory.c: Validate memory block size early To: linux-kernel@vger.kernel.org Cc: linux-mm@kvack.org, Greg Kroah-Hartman , "Rafael J. Wysocki" , Andrew Morton , Pavel Tatashin , Michal Hocko , Dan Williams References: <20190806090142.22709-1-david@redhat.com> From: David Hildenbrand Openpgp: preference=signencrypt Autocrypt: addr=david@redhat.com; prefer-encrypt=mutual; keydata= xsFNBFXLn5EBEAC+zYvAFJxCBY9Tr1xZgcESmxVNI/0ffzE/ZQOiHJl6mGkmA1R7/uUpiCjJ dBrn+lhhOYjjNefFQou6478faXE6o2AhmebqT4KiQoUQFV4R7y1KMEKoSyy8hQaK1umALTdL QZLQMzNE74ap+GDK0wnacPQFpcG1AE9RMq3aeErY5tujekBS32jfC/7AnH7I0v1v1TbbK3Gp XNeiN4QroO+5qaSr0ID2sz5jtBLRb15RMre27E1ImpaIv2Jw8NJgW0k/D1RyKCwaTsgRdwuK Kx/Y91XuSBdz0uOyU/S8kM1+ag0wvsGlpBVxRR/xw/E8M7TEwuCZQArqqTCmkG6HGcXFT0V9 PXFNNgV5jXMQRwU0O/ztJIQqsE5LsUomE//bLwzj9IVsaQpKDqW6TAPjcdBDPLHvriq7kGjt WhVhdl0qEYB8lkBEU7V2Yb+SYhmhpDrti9Fq1EsmhiHSkxJcGREoMK/63r9WLZYI3+4W2rAc UucZa4OT27U5ZISjNg3Ev0rxU5UH2/pT4wJCfxwocmqaRr6UYmrtZmND89X0KigoFD/XSeVv jwBRNjPAubK9/k5NoRrYqztM9W6sJqrH8+UWZ1Idd/DdmogJh0gNC0+N42Za9yBRURfIdKSb B3JfpUqcWwE7vUaYrHG1nw54pLUoPG6sAA7Mehl3nd4pZUALHwARAQABzSREYXZpZCBIaWxk ZW5icmFuZCA8ZGF2aWRAcmVkaGF0LmNvbT7CwX4EEwECACgFAljj9eoCGwMFCQlmAYAGCwkI BwMCBhUIAgkKCwQWAgMBAh4BAheAAAoJEE3eEPcA/4Na5IIP/3T/FIQMxIfNzZshIq687qgG 8UbspuE/YSUDdv7r5szYTK6KPTlqN8NAcSfheywbuYD9A4ZeSBWD3/NAVUdrCaRP2IvFyELj xoMvfJccbq45BxzgEspg/bVahNbyuBpLBVjVWwRtFCUEXkyazksSv8pdTMAs9IucChvFmmq3 jJ2vlaz9lYt/lxN246fIVceckPMiUveimngvXZw21VOAhfQ+/sofXF8JCFv2mFcBDoa7eYob s0FLpmqFaeNRHAlzMWgSsP80qx5nWWEvRLdKWi533N2vC/EyunN3HcBwVrXH4hxRBMco3jvM m8VKLKao9wKj82qSivUnkPIwsAGNPdFoPbgghCQiBjBe6A75Z2xHFrzo7t1jg7nQfIyNC7ez MZBJ59sqA9EDMEJPlLNIeJmqslXPjmMFnE7Mby/+335WJYDulsRybN+W5rLT5aMvhC6x6POK z55fMNKrMASCzBJum2Fwjf/VnuGRYkhKCqqZ8gJ3OvmR50tInDV2jZ1DQgc3i550T5JDpToh dPBxZocIhzg+MBSRDXcJmHOx/7nQm3iQ6iLuwmXsRC6f5FbFefk9EjuTKcLMvBsEx+2DEx0E UnmJ4hVg7u1PQ+2Oy+Lh/opK/BDiqlQ8Pz2jiXv5xkECvr/3Sv59hlOCZMOaiLTTjtOIU7Tq 7ut6OL64oAq+zsFNBFXLn5EBEADn1959INH2cwYJv0tsxf5MUCghCj/CA/lc/LMthqQ773ga uB9mN+F1rE9cyyXb6jyOGn+GUjMbnq1o121Vm0+neKHUCBtHyseBfDXHA6m4B3mUTWo13nid 0e4AM71r0DS8+KYh6zvweLX/LL5kQS9GQeT+QNroXcC1NzWbitts6TZ+IrPOwT1hfB4WNC+X 2n4AzDqp3+ILiVST2DT4VBc11Gz6jijpC/KI5Al8ZDhRwG47LUiuQmt3yqrmN63V9wzaPhC+ xbwIsNZlLUvuRnmBPkTJwwrFRZvwu5GPHNndBjVpAfaSTOfppyKBTccu2AXJXWAE1Xjh6GOC 8mlFjZwLxWFqdPHR1n2aPVgoiTLk34LR/bXO+e0GpzFXT7enwyvFFFyAS0Nk1q/7EChPcbRb hJqEBpRNZemxmg55zC3GLvgLKd5A09MOM2BrMea+l0FUR+PuTenh2YmnmLRTro6eZ/qYwWkC u8FFIw4pT0OUDMyLgi+GI1aMpVogTZJ70FgV0pUAlpmrzk/bLbRkF3TwgucpyPtcpmQtTkWS gDS50QG9DR/1As3LLLcNkwJBZzBG6PWbvcOyrwMQUF1nl4SSPV0LLH63+BrrHasfJzxKXzqg rW28CTAE2x8qi7e/6M/+XXhrsMYG+uaViM7n2je3qKe7ofum3s4vq7oFCPsOgwARAQABwsFl BBgBAgAPBQJVy5+RAhsMBQkJZgGAAAoJEE3eEPcA/4NagOsP/jPoIBb/iXVbM+fmSHOjEshl KMwEl/m5iLj3iHnHPVLBUWrXPdS7iQijJA/VLxjnFknhaS60hkUNWexDMxVVP/6lbOrs4bDZ NEWDMktAeqJaFtxackPszlcpRVkAs6Msn9tu8hlvB517pyUgvuD7ZS9gGOMmYwFQDyytpepo YApVV00P0u3AaE0Cj/o71STqGJKZxcVhPaZ+LR+UCBZOyKfEyq+ZN311VpOJZ1IvTExf+S/5 lqnciDtbO3I4Wq0ArLX1gs1q1XlXLaVaA3yVqeC8E7kOchDNinD3hJS4OX0e1gdsx/e6COvy qNg5aL5n0Kl4fcVqM0LdIhsubVs4eiNCa5XMSYpXmVi3HAuFyg9dN+x8thSwI836FoMASwOl C7tHsTjnSGufB+D7F7ZBT61BffNBBIm1KdMxcxqLUVXpBQHHlGkbwI+3Ye+nE6HmZH7IwLwV W+Ajl7oYF+jeKaH4DZFtgLYGLtZ1LDwKPjX7VAsa4Yx7S5+EBAaZGxK510MjIx6SGrZWBrrV TEvdV00F2MnQoeXKzD7O4WFbL55hhyGgfWTHwZ457iN9SgYi1JLPqWkZB0JRXIEtjd4JEQcx +8Umfre0Xt4713VxMygW0PnQt5aSQdMD58jHFxTk092mU+yIHj5LeYgvwSgZN4airXk5yRXl SE+xAvmumFBY Organization: Red Hat GmbH Message-ID: <74d3653a-59cd-15c8-4a11-13f57060ad2c@redhat.com> Date: Tue, 6 Aug 2019 11:26:49 +0200 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.7.2 MIME-Version: 1.0 In-Reply-To: <20190806090142.22709-1-david@redhat.com> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit X-Scanned-By: MIMEDefang 2.79 on 10.5.11.15 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.32]); Tue, 06 Aug 2019 09:26:52 +0000 (UTC) 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: On 06.08.19 11:01, David Hildenbrand wrote: "s/driver/drivers/" in subject. I think long term, we should move the whole memory block size configuration (set_memory_block_size_order() and memory_block_size_bytes()) into drivers/base/memory.c. > Let's validate the memory block size early, when initializing the > memory device infrastructure. Fail hard in case the value is not > suitable. > > As nobody checks the return value of memory_dev_init(), turn it into a > void function and fail with a panic in all scenarios instead. Otherwise, > we'll crash later during boot when core/drivers expect that the memory > device infrastructure (including memory_block_size_bytes()) works as > expected. > > Cc: Greg Kroah-Hartman > Cc: "Rafael J. Wysocki" > Cc: Andrew Morton > Cc: Pavel Tatashin > Cc: Michal Hocko > Cc: Dan Williams > Signed-off-by: David Hildenbrand > --- > drivers/base/memory.c | 31 +++++++++---------------------- > include/linux/memory.h | 6 +++--- > 2 files changed, 12 insertions(+), 25 deletions(-) > > diff --git a/drivers/base/memory.c b/drivers/base/memory.c > index 790b3bcd63a6..6bea4f3f8040 100644 > --- a/drivers/base/memory.c > +++ b/drivers/base/memory.c > @@ -100,21 +100,6 @@ unsigned long __weak memory_block_size_bytes(void) > } > EXPORT_SYMBOL_GPL(memory_block_size_bytes); > > -static unsigned long get_memory_block_size(void) > -{ > - unsigned long block_sz; > - > - block_sz = memory_block_size_bytes(); > - > - /* Validate blk_sz is a power of 2 and not less than section size */ > - if ((block_sz & (block_sz - 1)) || (block_sz < MIN_MEMORY_BLOCK_SIZE)) { > - WARN_ON(1); > - block_sz = MIN_MEMORY_BLOCK_SIZE; > - } > - > - return block_sz; > -} > - > /* > * Show the first physical section index (number) of this memory block. > */ > @@ -461,7 +446,7 @@ static DEVICE_ATTR_RO(removable); > static ssize_t block_size_bytes_show(struct device *dev, > struct device_attribute *attr, char *buf) > { > - return sprintf(buf, "%lx\n", get_memory_block_size()); > + return sprintf(buf, "%lx\n", memory_block_size_bytes()); > } > > static DEVICE_ATTR_RO(block_size_bytes); > @@ -811,19 +796,22 @@ static const struct attribute_group *memory_root_attr_groups[] = { > /* > * Initialize the sysfs support for memory devices... > */ > -int __init memory_dev_init(void) > +void __init memory_dev_init(void) > { > int ret; > int err; > unsigned long block_sz, nr; > > + /* Validate the configured memory block size */ > + block_sz = memory_block_size_bytes(); > + if (!is_power_of_2(block_sz) || block_sz < MIN_MEMORY_BLOCK_SIZE) > + panic("Memory block size not suitable: 0x%lx\n", block_sz); > + sections_per_block = block_sz / MIN_MEMORY_BLOCK_SIZE; > + > ret = subsys_system_register(&memory_subsys, memory_root_attr_groups); > if (ret) > goto out; > > - block_sz = get_memory_block_size(); > - sections_per_block = block_sz / MIN_MEMORY_BLOCK_SIZE; > - > /* > * Create entries for memory sections that were found > * during boot and have been initialized > @@ -839,8 +827,7 @@ int __init memory_dev_init(void) > > out: > if (ret) > - printk(KERN_ERR "%s() failed: %d\n", __func__, ret); > - return ret; > + panic("%s() failed: %d\n", __func__, ret); > } > > /** > diff --git a/include/linux/memory.h b/include/linux/memory.h > index 704215d7258a..0ebb105eb261 100644 > --- a/include/linux/memory.h > +++ b/include/linux/memory.h > @@ -79,9 +79,9 @@ struct mem_section; > #define IPC_CALLBACK_PRI 10 > > #ifndef CONFIG_MEMORY_HOTPLUG_SPARSE > -static inline int memory_dev_init(void) > +static inline void memory_dev_init(void) > { > - return 0; > + return; > } > static inline int register_memory_notifier(struct notifier_block *nb) > { > @@ -112,7 +112,7 @@ extern int register_memory_isolate_notifier(struct notifier_block *nb); > extern void unregister_memory_isolate_notifier(struct notifier_block *nb); > int create_memory_block_devices(unsigned long start, unsigned long size); > void remove_memory_block_devices(unsigned long start, unsigned long size); > -extern int memory_dev_init(void); > +extern void memory_dev_init(void); > extern int memory_notify(unsigned long val, void *v); > extern int memory_isolate_notify(unsigned long val, void *v); > extern struct memory_block *find_memory_block(struct mem_section *); > -- Thanks, David / dhildenb