From patchwork Wed Jul 2 02:03:27 2014 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Laura Abbott X-Patchwork-Id: 4463111 Return-Path: X-Original-To: patchwork-linux-arm@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork2.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.19.201]) by patchwork2.web.kernel.org (Postfix) with ESMTP id 368EABEEAA for ; Wed, 2 Jul 2014 02:06:52 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id 4FA4420353 for ; Wed, 2 Jul 2014 02:06:51 +0000 (UTC) Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.9]) (using TLSv1.2 with cipher DHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 724E120304 for ; Wed, 2 Jul 2014 02:06:50 +0000 (UTC) Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.80.1 #2 (Red Hat Linux)) id 1X29u3-0000q5-09; Wed, 02 Jul 2014 02:04:07 +0000 Received: from smtp.codeaurora.org ([198.145.11.231]) by bombadil.infradead.org with esmtps (Exim 4.80.1 #2 (Red Hat Linux)) id 1X29tu-0000mx-MV for linux-arm-kernel@lists.infradead.org; Wed, 02 Jul 2014 02:03:59 +0000 Received: from smtp.codeaurora.org (localhost [127.0.0.1]) by smtp.codeaurora.org (Postfix) with ESMTP id 8DA0613F9EF; Wed, 2 Jul 2014 02:03:35 +0000 (UTC) Received: by smtp.codeaurora.org (Postfix, from userid 486) id 7DF2E13F9F1; Wed, 2 Jul 2014 02:03:35 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on mail.kernel.org X-Spam-Level: X-Spam-Status: No, score=-1.9 required=5.0 tests=BAYES_00, T_RP_MATCHES_RCVD, UNPARSEABLE_RELAY autolearn=unavailable version=3.3.1 Received: from lauraa-linux1.qualcomm.com (i-global254.qualcomm.com [199.106.103.254]) (using TLSv1.1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) (Authenticated sender: lauraa@smtp.codeaurora.org) by smtp.codeaurora.org (Postfix) with ESMTPSA id CFB3513F9EF; Wed, 2 Jul 2014 02:03:34 +0000 (UTC) From: Laura Abbott To: Tushar Behera , Russell King , Kevin Hilman , Grant Likely , Rob Herring Subject: [PATCHv2 2/3] of: Add memory limiting function for flattened devicetrees Date: Tue, 1 Jul 2014 19:03:27 -0700 Message-Id: <1404266608-3274-2-git-send-email-lauraa@codeaurora.org> X-Mailer: git-send-email 1.8.2.1 In-Reply-To: <1404266608-3274-1-git-send-email-lauraa@codeaurora.org> References: <1404266608-3274-1-git-send-email-lauraa@codeaurora.org> X-Virus-Scanned: ClamAV using ClamSMTP X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20140701_190358_826462_44751DC1 X-CRM114-Status: GOOD ( 17.97 ) X-Spam-Score: -0.0 (/) Cc: devicetree@vger.kernel.org, linux-samsung-soc@vger.kernel.org, Laura Abbott , linaro-kernel@lists.linaro.org, afaerber@suse.de, linux-arm-kernel@lists.infradead.org X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.18-1 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , MIME-Version: 1.0 Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org X-Virus-Scanned: ClamAV using ClamSMTP Buggy bootloaders may pass bogus memory entries in the devicetree. Add of_fdt_limit_memory to add an upper bound on the number of entries that can be present in the devicetree. Signed-off-by: Laura Abbott --- drivers/of/fdt.c | 48 ++++++++++++++++++++++++++++++++++++++++++++++++ include/linux/of_fdt.h | 1 + 2 files changed, 49 insertions(+) diff --git a/drivers/of/fdt.c b/drivers/of/fdt.c index 55bfca9..fd5db5a 100644 --- a/drivers/of/fdt.c +++ b/drivers/of/fdt.c @@ -26,6 +26,54 @@ #include /* for COMMAND_LINE_SIZE */ #include +/* + * of_fdt_limit_memory - limit the number of regions in the /memory node + * @limit: maximum entries + * + * Adjust the flattened device tree to have at most 'limit' number of + * memory entries in the /memory node. This function may be called + * any time after initial_boot_param is set. + */ +void of_fdt_limit_memory(int limit) +{ + int memory; + int len; + const void *val; + int nr_address_cells = OF_ROOT_NODE_ADDR_CELLS_DEFAULT; + int nr_size_cells = OF_ROOT_NODE_SIZE_CELLS_DEFAULT; + const uint32_t *addr_prop; + const uint32_t *size_prop; + int root_offset; + int cell_size; + + root_offset = fdt_path_offset(initial_boot_params, "/"); + if (root_offset < 0) + return; + + addr_prop = fdt_getprop(initial_boot_params, root_offset, + "#address-cells", NULL); + if (addr_prop) + nr_address_cells = fdt32_to_cpu(*addr_prop); + + size_prop = fdt_getprop(initial_boot_params, root_offset, + "#size-cells", NULL); + if (size_prop) + nr_size_cells = fdt32_to_cpu(*size_prop); + + cell_size = sizeof(uint32_t)*(nr_address_cells + nr_size_cells); + + memory = fdt_path_offset(initial_boot_params, "/memory"); + if (memory > 0) { + val = fdt_getprop(initial_boot_params, memory, "reg", &len); + if (len > limit*cell_size) { + len = limit*cell_size; + pr_debug("Limiting number of entries to %d\n", limit); + fdt_setprop(initial_boot_params, memory, "reg", val, + len); + } + } +} + /** * of_fdt_is_compatible - Return true if given node from the given blob has * compat in its compatible list diff --git a/include/linux/of_fdt.h b/include/linux/of_fdt.h index d600993..1aea25c 100644 --- a/include/linux/of_fdt.h +++ b/include/linux/of_fdt.h @@ -86,6 +86,7 @@ extern void unflatten_and_copy_device_tree(void); extern void early_init_devtree(void *); extern void early_get_first_memblock_info(void *, phys_addr_t *); extern u64 fdt_translate_address(const void *blob, int node_offset); +extern void of_fdt_limit_memory(int limit); #else /* CONFIG_OF_FLATTREE */ static inline void early_init_fdt_scan_reserved_mem(void) {} static inline const char *of_flat_dt_get_machine_name(void) { return NULL; }