Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753578AbbFVDlz (ORCPT ); Sun, 21 Jun 2015 23:41:55 -0400 Received: from mail-pd0-f177.google.com ([209.85.192.177]:34718 "EHLO mail-pd0-f177.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751485AbbFVDlp (ORCPT ); Sun, 21 Jun 2015 23:41:45 -0400 From: Peng Fan To: ulf.hansson@linaro.org Cc: adrian.hunter@intel.com, tim.kryger@gmail.com, b29396@freescale.com, haibo.chen@freescale.com, linux-mmc@vger.kernel.org, linux-kernel@vger.kernel.org, van.freenix@gmail.com Subject: [PATCH] mmc: host: sdhci check parameters before call dma_free_coherent Date: Mon, 22 Jun 2015 11:41:23 +0800 Message-Id: <1434944483-4888-1-git-send-email-van.freenix@gmail.com> X-Mailer: git-send-email 1.8.4 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 6028 Lines: 120 We should not call dma_free_coherent if host->adma_table is NULL, otherwise may trigger panic. >From DMA-API.txt: " void dma_free_coherent(struct device *dev, size_t size, void *cpu_addr, dma_addr_t dma_handle) Free a region of consistent memory you previously allocated. dev, size and dma_handle must all be the same as those passed into dma_alloc_coherent(). cpu_addr must be the virtual address returned by the dma_alloc_coherent(). " So we should check cpu_addr, but not directly call dma_free_coherent. I met this when porting xen, log: " sdhci: Secure Digital Host Controller Interface driver sdhci: Copyright(c) Pierre Ossman sdhci-pltfm: SDHCI platform and OF driver helper Unable to handle kernel NULL pointer dereference at virtual address 00000000 pgd = 80004000 [00000000] *pgd=00000000 Internal error: Oops: 5 [#1] PREEMPT SMP ARM Modules linked in: CPU: 0 PID: 1 Comm: swapper/0 Not tainted 3.14.38-02383-g5ccf32b-dirty #22 task: 84074000 ti: 84078000 task.ti: 84078000 PC is at bitmap_clear+0xc0/0xdc LR is at bitmap_clear+0x54/0xdc pc : [<8029deb8>] lr : [<8029de4c>] psr: 20000193 sp : 84079d80 ip : 00000001 fp : 00000000 r10: 00077fff r9 : 00000404 r8 : 00000001 r7 : 00000001 r6 : 00000001 r5 : 00000000 r4 : ffffffff r3 : 00000001 r2 : 00000001 r1 : 20000193 r0 : 00000015 Flags: nzCv IRQs off FIQs on Mode SVC_32 ISA ARM Segment kernel Control: 10c53c7d Table: 8800406a DAC: 00000015 Process swapper/0 (pid: 1, stack limit = 0x84078238) Stack: (0x84079d80 to 0x8407a000) 9d80: 80000113 00000000 87efa000 81109918 00001000 800197f8 84128558 00080008 9da0: 84079dec 000000d0 84bfeac0 84126c10 84126c10 ffffffff 00000404 ffffffff 9dc0: 00000000 00000402 00000000 00000000 84126c10 80310ba8 ffffffff 00000000 9de0: 00000000 00000524 84078000 00000000 00000000 ffffffff ffffffff 84bfeac0 9e00: 84bfe800 8000b407 07eb0000 8116e0f8 00000000 804ee81c ffffffff ffffffff 9e20: 00000000 84126c10 84c92010 84bfeac0 00000000 84126c10 84126c00 84bfeac0 9e40: 84078030 804f08e4 804f03d8 84126c10 fffffdfb 8115401c 8115401c 00000000 9e60: 0000010f 80362330 803622ec 84126c10 811c8098 00000000 8115401c 80360b1c 9e80: 84126c10 8115401c 84126c44 00000000 80de1888 80360d28 00000000 8115401c 9ea0: 80360c9c 8035f10c 8406965c 84123634 8115401c 84c8bf80 8112f3c8 803602bc 9ec0: 80d08314 8115401c 00000006 8115401c 00000006 8116e080 8116e080 8036130c 9ee0: 00000000 80e00f78 00000006 800088dc 8400f900 80c94fe0 840bd480 80735184 9f00: 00000000 8116e080 0000150c 8012d430 00000000 811105b0 60000113 00000001 9f20: 87ffc576 8075ca38 0000010f 8004b0f0 80d66884 00000006 87ffc583 00000006 9f40: 811105a0 80e00f78 00000006 8116e080 8116e080 80da150c 0000010f 80df4154 9f60: 80df4148 80da1c4c 00000006 00000006 80da150c 9355553c 84079f9c 80731338 9f80: 00000000 00000000 80727254 00000000 00000000 00000000 00000000 00000000 9fa0: 00000000 8072725c 00000000 8000ecf8 00000000 00000000 00000000 00000000 9fc0: 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 9fe0: 00000000 00000000 00000000 00000000 00000013 00000000 9355553c 9355553c [<8029deb8>] (bitmap_clear) from [<800197f8>] (__arm_dma_free.isra.18+0xe4/0x228) [<800197f8>] (__arm_dma_free.isra.18) from [<80310ba8>] (xen_swiotlb_free_coherent+0xfc/0x140) [<80310ba8>] (xen_swiotlb_free_coherent) from [<804ee81c>] (sdhci_add_host+0xb34/0xe64) [<804ee81c>] (sdhci_add_host) from [<804f08e4>] (sdhci_esdhc_imx_probe+0x50c/0x808) [<804f08e4>] (sdhci_esdhc_imx_probe) from [<80362330>] (platform_drv_probe+0x44/0xa4) [<80362330>] (platform_drv_probe) from [<80360b1c>] (driver_probe_device+0x120/0x25c) [<80360b1c>] (driver_probe_device) from [<80360d28>] (__driver_attach+0x8c/0x90) [<80360d28>] (__driver_attach) from [<8035f10c>] (bus_for_each_dev+0x60/0x94) [<8035f10c>] (bus_for_each_dev) from [<803602bc>] (bus_add_driver+0x148/0x1f0) [<803602bc>] (bus_add_driver) from [<8036130c>] (driver_register+0x78/0xf8) [<8036130c>] (driver_register) from [<800088dc>] (do_one_initcall+0xf8/0x144) [<800088dc>] (do_one_initcall) from [<80da1c4c>] (kernel_init_freeable+0x138/0x1d8) [<80da1c4c>] (kernel_init_freeable) from [<8072725c>] (kernel_init+0x8/0xf0) [<8072725c>] (kernel_init) from [<8000ecf8>] (ret_from_fork+0x14/0x3c) Code: 10866003 1206601f 10633006 11e02312 (e5953000) ---[ end trace f6f103bb73cc0503 ]--- note: swapper/0[1] exited with preempt_count 1 Kernel panic - not syncing: Attempted to kill init! exitcode=0x0000000b" Because dma_alloc_coherent fail, it returns NULL, then "if (!host->adma_table || !host->align_buffer)" will return true, then dma_free_coherent trigger panic. After applying this patch, no panic and all work well, kernel log: " sdhci: Secure Digital Host Controller Interface driver sdhci: Copyright(c) Pierre Ossman sdhci-pltfm: SDHCI platform and OF driver helper mmc0: Unable to allocate ADMA buffers. Falling back to standard DMA. mmc0: no vqmmc regulator found mmc0: SDHCI controller on 30b40000.usdhc [30b40000.usdhc] using DMA " Signed-off-by: Peng Fan --- drivers/mmc/host/sdhci.c | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-) diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c index 706bb60..52e2327 100644 --- a/drivers/mmc/host/sdhci.c +++ b/drivers/mmc/host/sdhci.c @@ -2978,8 +2978,11 @@ int sdhci_add_host(struct sdhci_host *host) GFP_KERNEL); host->align_buffer = kmalloc(host->align_buffer_sz, GFP_KERNEL); if (!host->adma_table || !host->align_buffer) { - dma_free_coherent(mmc_dev(mmc), host->adma_table_sz, - host->adma_table, host->adma_addr); + if (host->adma_table) + dma_free_coherent(mmc_dev(mmc), + host->adma_table_sz, + host->adma_table, + host->adma_addr); kfree(host->align_buffer); pr_warn("%s: Unable to allocate ADMA buffers - falling back to standard DMA\n", mmc_hostname(mmc)); -- 1.8.4 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in Please read the FAQ at http://www.tux.org/lkml/