{"id":810816,"url":"http://patchwork.ozlabs.org/api/1.2/patches/810816/?format=json","web_url":"http://patchwork.ozlabs.org/project/linux-mtd/patch/20170906214502.26748-1-cyrille.pitchen@wedev4u.fr/","project":{"id":3,"url":"http://patchwork.ozlabs.org/api/1.2/projects/3/?format=json","name":"Linux MTD development","link_name":"linux-mtd","list_id":"linux-mtd.lists.infradead.org","list_email":"linux-mtd@lists.infradead.org","web_url":null,"scm_url":null,"webscm_url":null,"list_archive_url":"","list_archive_url_format":"","commit_url_format":""},"msgid":"<20170906214502.26748-1-cyrille.pitchen@wedev4u.fr>","list_archive_url":null,"date":"2017-09-06T21:45:02","name":"mtd: spi-nor: fix DMA unsafe buffer issue in spi_nor_read_sfdp()","commit_ref":null,"pull_url":null,"state":"accepted","archived":false,"hash":"d176dc91fc64ea2476106eabe54f30f8a98cfeb4","submitter":{"id":70551,"url":"http://patchwork.ozlabs.org/api/1.2/people/70551/?format=json","name":"Cyrille Pitchen","email":"cyrille.pitchen@wedev4u.fr"},"delegate":{"id":58324,"url":"http://patchwork.ozlabs.org/api/1.2/users/58324/?format=json","username":"bbrezillon","first_name":"Boris","last_name":"Brezillon","email":"boris.brezillon@free-electrons.com"},"mbox":"http://patchwork.ozlabs.org/project/linux-mtd/patch/20170906214502.26748-1-cyrille.pitchen@wedev4u.fr/mbox/","series":[{"id":1890,"url":"http://patchwork.ozlabs.org/api/1.2/series/1890/?format=json","web_url":"http://patchwork.ozlabs.org/project/linux-mtd/list/?series=1890","date":"2017-09-06T21:45:02","name":"mtd: spi-nor: fix DMA unsafe buffer issue in spi_nor_read_sfdp()","version":1,"mbox":"http://patchwork.ozlabs.org/series/1890/mbox/"}],"comments":"http://patchwork.ozlabs.org/api/patches/810816/comments/","check":"pending","checks":"http://patchwork.ozlabs.org/api/patches/810816/checks/","tags":{},"related":[],"headers":{"Return-Path":"","X-Original-To":"incoming@patchwork.ozlabs.org","Delivered-To":"patchwork-incoming@bilbo.ozlabs.org","Authentication-Results":["ozlabs.org; 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Wed, 06 Sep 2017 21:45:40 +0000","from player732.ha.ovh.net (b6.ovh.net [213.186.33.56])\n\tby mo3.mail-out.ovh.net (Postfix) with ESMTP id 8F29A149189\n\tfor ;\n\tWed, 6 Sep 2017 23:45:13 +0200 (CEST)","from mountainer.wedev4u.int (cor13-1-82-232-94-13.fbx.proxad.net\n\t[82.232.94.13]) (Authenticated sender: cyrille.pitchen@wedev4u.fr)\n\tby player732.ha.ovh.net (Postfix) with ESMTPSA id AF5D820075;\n\tWed, 6 Sep 2017 23:45:03 +0200 (CEST)"],"DKIM-Signature":"v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed;\n\td=lists.infradead.org; s=bombadil.20170209; h=Sender:\n\tContent-Transfer-Encoding:Content-Type:MIME-Version:Cc:List-Subscribe:\n\tList-Help:List-Post:List-Archive:List-Unsubscribe:List-Id:Message-Id:Date:\n\tSubject:To:From:Reply-To:Content-ID:Content-Description:Resent-Date:\n\tResent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:In-Reply-To:\n\tReferences:List-Owner; bh=QtzUPdV39dIIEm1hUXq7l8duZ3EUuIALBOE/2P9/Xek=;\n\tb=agC\n\tAzWLbjOvbhoai2WYQdrzg5R+j+GzeqPudZEJGNu9aiXYeNSmhkooiZ8qygVXKH/lWnl8qsYdblqQh\n\tcZEILu4qdYb2wEDtwWvkFbAU4NN0yPdPp/pqCpGChmpPf5VT8+2037tMJk7DNvxyruLIHPFjKJP4/\n\td4nYPJ2NbxGA8TUga/xgTcjDbioxfdnbnndqoraGr9mNXHrNgj8X5u2uHMnG/ZUKwlHJXVmmRCHlZ\n\tvb1vbGK4NaYeyGM5EXng/IZXeBdma7XuBktAlCbdNUSmbaP7VjE7pmF4HEXKABlG5ucU7+bRL7WMB\n\trntpTaaU/fjB2P/zApqw7DS+5dP68wQ==;","From":"Cyrille Pitchen ","To":"marek.vasut@gmail.com, linux-mtd@lists.infradead.org,\n\tgeert@linux-m68k.org","Subject":"[PATCH] mtd: spi-nor: fix DMA unsafe buffer issue in\n\tspi_nor_read_sfdp()","Date":"Wed, 6 Sep 2017 23:45:02 +0200","Message-Id":"<20170906214502.26748-1-cyrille.pitchen@wedev4u.fr>","X-Mailer":"git-send-email 2.11.0","X-Ovh-Tracer-Id":"7811775029125011336","X-VR-SPAMSTATE":"OK","X-VR-SPAMSCORE":"0","X-VR-SPAMCAUSE":"gggruggvucftvghtrhhoucdtuddrfeelledrfedugddtlecutefuodetggdotefrodftvfcurfhrohhfihhlvgemucfqggfjpdevjffgvefmvefgnecuuegrihhlohhuthemuceftddtnecu","X-CRM114-Version":"20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 ","X-CRM114-CacheID":"sfid-20170906_144538_360140_3F364F8E ","X-CRM114-Status":"GOOD ( 13.22 )","X-Spam-Score":"-2.6 (--)","X-Spam-Report":"SpamAssassin version 3.4.1 on bombadil.infradead.org summary:\n\tContent analysis details: (-2.6 points)\n\tpts rule name description\n\t---- ----------------------\n\t--------------------------------------------------\n\t-0.7 RCVD_IN_DNSWL_LOW RBL: Sender listed at http://www.dnswl.org/,\n\tlow trust [46.105.75.36 listed in list.dnswl.org]\n\t-0.0 RCVD_IN_MSPIKE_H3 RBL: Good reputation (+3)\n\t[46.105.75.36 listed in wl.mailspike.net]\n\t-0.0 SPF_PASS SPF: sender matches SPF record\n\t-1.9 BAYES_00 BODY: Bayes spam probability is 0 to 1%\n\t[score: 0.0000]\n\t-0.0 RCVD_IN_MSPIKE_WL Mailspike good senders","X-BeenThere":"linux-mtd@lists.infradead.org","X-Mailman-Version":"2.1.21","Precedence":"list","List-Id":"Linux MTD discussion mailing list ","List-Unsubscribe":",\n\t","List-Archive":"","List-Post":"","List-Help":"","List-Subscribe":",\n\t","Cc":"boris.brezillon@free-electrons.com, richard@nod.at,\n\tlinux-kernel@vger.kernel.org,\n\tCyrille Pitchen , \n\tcomputersforpeace@gmail.com, dwmw2@infradead.org","MIME-Version":"1.0","Content-Type":"text/plain; charset=\"us-ascii\"","Content-Transfer-Encoding":"7bit","Sender":"\"linux-mtd\" ","Errors-To":"linux-mtd-bounces+incoming=patchwork.ozlabs.org@lists.infradead.org"},"content":"spi_nor_read_sfdp() calls nor->read() to read the SFDP data.\nWhen the m25p80 driver is used (pretty common case), nor->read() is then\nimplemented by the m25p80_read() function, which is likely to initialize a\n'struct spi_transfer' from its buf argument before appending this\nstructure inside the 'struct spi_message' argument of spi_sync().\n\nBesides the SPI sub-system states that both .tx_buf and .rx_buf members of\n'struct spi_transfer' must point into dma-safe memory. However, two of the\nthree calls of spi_nor_read_sfdp() were given pointers to stack allocated\nmemory as buf argument, hence not in a dma-safe area.\nHopefully, the third and last call of spi_nor_read_sfdp() was already\ngiven a kmalloc'ed buffer argument, hence dma-safe.\n\nSo this patch fixes this issue by introducing a\nspi_nor_read_sfdp_dma_unsafe() function which simply wraps the existing\nspi_nor_read_sfdp() function and uses some kmalloc'ed memory as a bounce\nbuffer.\n\nReported-by: Geert Uytterhoeven \nSigned-off-by: Cyrille Pitchen \n---\n\nCompiled but not tested yet!\n\n drivers/mtd/spi-nor/spi-nor.c | 36 +++++++++++++++++++++++++++++++++---\n 1 file changed, 33 insertions(+), 3 deletions(-)","diff":"diff --git a/drivers/mtd/spi-nor/spi-nor.c b/drivers/mtd/spi-nor/spi-nor.c\nindex cf1d4a15e10a..05254dd6a4a0 100644\n--- a/drivers/mtd/spi-nor/spi-nor.c\n+++ b/drivers/mtd/spi-nor/spi-nor.c\n@@ -1784,7 +1784,7 @@ spi_nor_set_pp_settings(struct spi_nor_pp_command *pp,\n * @nor:\tpointer to a 'struct spi_nor'\n * @addr:\toffset in the SFDP area to start reading data from\n * @len:\tnumber of bytes to read\n- * @buf:\tbuffer where the SFDP data are copied into\n+ * @buf:\tbuffer where the SFDP data are copied into (dma-safe memory)\n *\n * Whatever the actual numbers of bytes for address and dummy cycles are\n * for (Fast) Read commands, the Read SFDP (5Ah) instruction is always\n@@ -1829,6 +1829,36 @@ static int spi_nor_read_sfdp(struct spi_nor *nor, u32 addr,\n \treturn ret;\n }\n \n+/**\n+ * spi_nor_read_sfdp_dma_unsafe() - read Serial Flash Discoverable Parameters.\n+ * @nor:\tpointer to a 'struct spi_nor'\n+ * @addr:\toffset in the SFDP area to start reading data from\n+ * @len:\tnumber of bytes to read\n+ * @buf:\tbuffer where the SFDP data are copied into\n+ *\n+ * Wrap spi_nor_read_sfdp() using a kmalloc'ed bounce buffer as @buf is now not\n+ * guaranteed to be dma-safe.\n+ *\n+ * Return: -ENOMEM if kmalloc() fails, the return code of spi_nor_read_sfdp()\n+ * otherwise.\n+ */\n+static int spi_nor_read_sfdp_dma_unsafe(struct spi_nor *nor, u32 addr,\n+\t\t\t\t\tsize_t len, void *buf)\n+{\n+\tvoid *dma_safe_buf;\n+\tint ret;\n+\n+\tdma_safe_buf = kmalloc(len, GFP_KERNEL);\n+\tif (!dma_safe_buf)\n+\t\treturn -ENOMEM;\n+\n+\tret = spi_nor_read_sfdp(nor, addr, len, dma_safe_buf);\n+\tmemcpy(buf, dma_safe_buf, len);\n+\tkfree(dma_safe_buf);\n+\n+\treturn ret;\n+}\n+\n struct sfdp_parameter_header {\n \tu8\t\tid_lsb;\n \tu8\t\tminor;\n@@ -2101,7 +2131,7 @@ static int spi_nor_parse_bfpt(struct spi_nor *nor,\n \t\t bfpt_header->length * sizeof(u32));\n \taddr = SFDP_PARAM_HEADER_PTP(bfpt_header);\n \tmemset(&bfpt, 0, sizeof(bfpt));\n-\terr = spi_nor_read_sfdp(nor, addr, len, &bfpt);\n+\terr = spi_nor_read_sfdp_dma_unsafe(nor, addr, len, &bfpt);\n \tif (err < 0)\n \t\treturn err;\n \n@@ -2243,7 +2273,7 @@ static int spi_nor_parse_sfdp(struct spi_nor *nor,\n \tint i, err;\n \n \t/* Get the SFDP header. */\n-\terr = spi_nor_read_sfdp(nor, 0, sizeof(header), &header);\n+\terr = spi_nor_read_sfdp_dma_unsafe(nor, 0, sizeof(header), &header);\n \tif (err < 0)\n \t\treturn err;\n \n","prefixes":[]}