Hi,
Please find the patch inline.
>From ce326fd60f23f3de75ff7349bf84625cfc6e5378 Mon Sep 17 00:00:00 2001
From: Bhuvanesh Surachari <bhuvanesh_surachari@xxxxxxxxxx>
Date: Mon, 1 Dec 2014 02:23:02 -0500
Subject: [PATCH] mmc: queue:Improve error handling during allocation of
bounce buffers.
Allocation of previous bounce buffer in mmc_init_queue when the current
bounce buffer allocation fails was leading to a crash later in
__blk_segment_map_sg. Error handling is improved by allocating previous
bounce buffer only if the current bounce buffer allocation succeeds.
Signed-off-by: Bhuvanesh Surachari <bhuvanesh_surachari@xxxxxxxxxx>
---
drivers/mmc/card/queue.c | 17 ++++++++++-------
1 file changed, 10 insertions(+), 7 deletions(-)
diff --git a/drivers/mmc/card/queue.c b/drivers/mmc/card/queue.c
index cfa6110..631fc60 100644
--- a/drivers/mmc/card/queue.c
+++ b/drivers/mmc/card/queue.c
@@ -232,13 +232,16 @@ int mmc_init_queue(struct mmc_queue *mq, struct mmc_card *card,
if (!mqrq_cur->bounce_buf) {
pr_warn("%s: unable to allocate bounce cur buffer\n",
mmc_card_name(card));
- }
- mqrq_prev->bounce_buf = kmalloc(bouncesz, GFP_KERNEL);
- if (!mqrq_prev->bounce_buf) {
- pr_warn("%s: unable to allocate bounce prev buffer\n",
- mmc_card_name(card));
- kfree(mqrq_cur->bounce_buf);
- mqrq_cur->bounce_buf = NULL;
+ } else {
+ mqrq_prev->bounce_buf = kmalloc(bouncesz,
+ GFP_KERNEL);
+ if (!mqrq_prev->bounce_buf) {
+ pr_warn("%s: unable to "
+ "allocate bounce prev buffer\n",
+ mmc_card_name(card));
+ kfree(mqrq_cur->bounce_buf);
+ mqrq_cur->bounce_buf = NULL;
+ }
}
}
--
1.7.9.5
Thank you,
Regards,
Bhuvanesh
On 12/01/2014 05:41 AM, Ulf Hansson wrote:
> On 1 December 2014 at 11:24, Bhuvanesh <bhuvanesh_surachari@xxxxxxxxxx> wrote:
>> Hi,
>>
>> During our rigorous testing of inserting and removing SD card, we
>> found exception in the kernel. Please find the backtrace is as below:
>>
>> [ 1899.301985] Backtrace:
>> [ 1899.325461] [<800117c4>] (dump_backtrace+0x0/0x100) from [<803f2cf4>] (dump_stack+0x18/0x1c)
>> [ 1899.375000] [<803f2cdc>] (dump_stack+0x0/0x1c) from [<800b4038>] (warn_alloc_failed+0xec/0x10c)
>> [ 1899.415523] [<800b3f4c>] (warn_alloc_failed+0x0/0x10c) from [<800b6d10>] (__alloc_pages_nodemask+0x764/0x890)
>> [ 1899.452807] [<800b65ac>] (__alloc_pages_nodemask+0x0/0x890) from [<800b6e54>] (__get_free_pages+0x18/0x54)
>> [ 1899.474315] [<800b6e3c>] (__get_free_pages+0x0/0x54) from [<800e4504>] (kmalloc_order_trace+0x2c/0xe8)
>> [ 1899.496752] [<800e44d8>] (kmalloc_order_trace+0x0/0xe8) from [<800e5c4c>] (__kmalloc+0x38/0x1e4)
>> [ 1899.520215] [<800e5c14>] (__kmalloc+0x0/0x1e4) from [<8026ac50>] (mmc_init_queue+0x198/0x444)
>> [ 1899.543510] [<8026aab8>] (mmc_init_queue+0x0/0x444) from [<80268638>] (mmc_blk_alloc_req+0x184/0x354)
>> [ 1899.576244] [<802684b4>] (mmc_blk_alloc_req+0x0/0x354) from [<80268f54>] (mmc_blk_probe+0x7c/0x28c)
>> [ 1899.598040] [<80268ed8>] (mmc_blk_probe+0x0/0x28c) from [<8025e8f0>] (mmc_bus_probe+0x1c/0x20)
>> [ 1899.616881] [<8025e8d4>] (mmc_bus_probe+0x0/0x20) from [<802a0d2c>] (driver_probe_device+0xb4/0x204)
>> [ 1899.654133] [<802a0c78>] (driver_probe_device+0x0/0x204) from [<802a0eac>] (__device_attach+0x30/0x4c)
>> [ 1899.683947] [<802a0e7c>] (__device_attach+0x0/0x4c) from [<8029f3b4>] (bus_for_each_drv+0x80/0x94)
>> [ 1899.704480] [<8029f334>] (bus_for_each_drv+0x0/0x94) from [<802a0c2c>] (device_attach+0x70/0x94)
>> [ 1899.755221] [<802a0bbc>] (device_attach+0x0/0x94) from [<802a01e0>] (bus_probe_device+0x30/0xa0)
>> [ 1899.779171] [<802a01b0>] (bus_probe_device+0x0/0xa0) from [<8029e8bc>] (device_add+0x42c/0x570)
>> [ 1899.799454] [<8029e490>] (device_add+0x0/0x570) from [<8025eda0>] (mmc_add_card+0x188/0x1e4)
>> [ 1899.829667] [<8025ec18>] (mmc_add_card+0x0/0x1e4) from [<802637bc>] (mmc_attach_sd+0x188/0x210)
>> [ 1899.870286] [<80263634>] (mmc_attach_sd+0x0/0x210) from [<8025e508>] (mmc_rescan+0x240/0x2ac)
>> [ 1899.907069] [<8025e2c8>] (mmc_rescan+0x0/0x2ac) from [<8003cde0>] (process_one_work+0x2cc/0x460)
>> [ 1899.939740] [<8003cb14>] (process_one_work+0x0/0x460) from [<8003d240>] (worker_thread+0x298/0x3ec)
>> [ 1899.967170] [<8003cfa8>] (worker_thread+0x0/0x3ec) from [<80042490>] (kthread+0xb4/0xc0)
>> [ 1899.995888] [<800423dc>] (kthread+0x0/0xc0) from [<8000d9b8>] (ret_from_fork+0x14/0x3c)
>> [ 1902.728313] Unable to handle kernel NULL pointer dereference at virtual address 00000000
>> [ 1902.766137] pgd = 80004000
>> [ 1902.781650] [00000000] *pgd=00000000
>> [ 1902.790794] Internal error: Oops: 17 [#1] PREEMPT SMP ARM
>> [ 1902.796302] Modules linked in: nls_iso8859_1 nls_cp437 vfat fat rfcomm bnep hci_uart bluetooth mascassi sg scsi_mod pram asix usbnet mii zforce_ts caam unifi_sdio_v6 spidev mxc_asrc rtc_inc exchnd mousedev imx2_wdt inc_wdt adc_inc input_inc boardcfg snd_aloop i2c_dev imx_thermal thermal_sys evdev snd_soc_fsl_ssi snd_soc_imx_generic pwm_inc snd_soc_imx_audmux snd_soc_imx_pcm snd_soc_fsl_asrc_cpu snd_soc_fsl_asrc_dma snd_soc_fsl_esai snd_soc_fsl_asrc mxc_asrc_core snd_soc_skeleton snd_soc_core regmap_spi snd_pcm regmap_i2c gpio_inc snd_timer snd_compress snd_page_alloc pwm_bl backlight cpu_run ipv6 autofs4 adv7182 mx6_vout videobuf2_core videobuf2_dma_contig videobuf2_memops imx6_v4l2_capture v4l2_int_device v4l2_common videodev mxc_vpu galcore imx_parallel_display imx_hdmi imx_ldb imx_ipuv3_plane imx_ipuv3_crtc imx_ipu_v3 imx_fbdev imxdrm drm_kms_helper fb drm
>> [ 1902.873563] CPU: 0 Not tainted (3.8.13.27-03391-g4e6f494 #1)
>> [ 1902.879633] PC is at __blk_segment_map_sg+0xfc/0x140
>> [ 1902.884654] LR is at blk_rq_map_sg+0xa0/0x1d8
>> [ 1902.889069] pc : [<802240fc>] lr : [<802241e0>] psr: 60000013
>> [ 1902.889069] sp : 85f1ddb8 ip : 85f1ddf0 fp : 85f1ddec
>> [ 1902.900601] r10: 85f1de04 r9 : 00000000 r8 : 00000000
>> [ 1902.905880] r7 : 85f1de00 r6 : 00001000 r5 : 85f1de04 r4 : ad141944
>> [ 1902.912461] r3 : 00000000 r2 : 807757c0 r1 : 00000000 r0 : ac2872a0
>> [ 1902.919044] Flags: nZCv IRQs on FIQs on Mode SVC_32 ISA ARM Segment kernel
>> [ 1902.926408] Control: 10c5387d Table: 3de5404a DAC: 00000015
>> [ 1902.932209] Process mmcqd/0 (pid: 1687, stack limit = 0x85f1c238)
>> [ 1902.938356] Stack: (0x85f1ddb8 to 0x85f1e000)
>> [ 1902.942768] dda0: 9c61f238 00000000
>> [ 1902.951004] ddc0: 00000000 ac2872a0 ad07f1b0 ad141900 00000001 00000000 00000000 85f1de04
>> [ 1902.959240] dde0: 85f1de3c 85f1ddf0 802241e0 8022400c 85f1de04 85f1de08 85f1de0c 0000001c
>> [ 1902.967477] de00: 00000000 00000000 00000000 00000001 85f1de54 835e0430 835e2400 ad07f1b0
>> [ 1902.975713] de20: 00000008 835e0434 835e0408 835e0400 85f1de5c 85f1de40 8026b06c 8022414c
>> [ 1902.983951] de40: 835e0430 835e2400 ad07f1b0 00000008 85f1de94 85f1de60 80268c14 8026b04c
>> [ 1902.992188] de60: 803f90d8 00000000 85f1de8c 835e2400 ad07f1b0 835e0408 ac07f000 ad07f1b0
>> [ 1903.000426] de80: 835e0400 835e0434 85f1dedc 85f1de98 802699a8 80268994 85f1deb4 00000000
>> [ 1903.008665] dea0: 00000000 00000000 00100100 00200200 803f7f98 ad07f1b0 835e2400 835e0408
>> [ 1903.016903] dec0: ac07f000 835e0400 85f1c000 835e0400 85f1df24 85f1dee0 8026a210 80269920
>> [ 1903.025142] dee0: 00000000 ad07f1b0 85f1df0c 85f1def8 802204e0 120d0000 120d0000 835e0408
>> [ 1903.033381] df00: ad07f1b0 835e0410 ac2872a0 85f1c028 85f1c000 00000001 85f1df5c 85f1df28
>> [ 1903.041619] df20: 8026a89c 80269d4c 00000000 120d0000 8026a7bc ac099c28 00000000 835e0408
>> [ 1903.049857] df40: 8026a7bc 00000000 00000000 00000000 85f1dfac 85f1df60 80042490 8026a7c8
>> [ 1903.058094] df60: 803f9134 00000000 85f1df94 835e0408 00000000 00000000 85f1df78 85f1df78
>> [ 1903.066330] df80: 00000000 00000000 85f1df88 85f1df88 ac099c28 800423dc 00000000 00000000
>> [ 1903.074566] dfa0: 00000000 85f1dfb0 8000d9b8 800423e8 00000000 00000000 00000000 00000000
>> [ 1903.082801] dfc0: 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
>> [ 1903.091036] dfe0: 00000000 00000000 00000000 00000000 00000013 00000000 5ae06eda 0a6e879f
>> [ 1903.099264] Backtrace:
>> [ 1903.101793] [<80224000>] (__blk_segment_map_sg+0x0/0x140) from [<802241e0>] (blk_rq_map_sg+0xa0/0x1d8)
>> [ 1903.111168] [<80224140>] (blk_rq_map_sg+0x0/0x1d8) from [<8026b06c>] (mmc_queue_map_sg+0x2c/0x94)
>> [ 1903.120105] [<8026b040>] (mmc_queue_map_sg+0x0/0x94) from [<80268c14>] (mmc_blk_rw_rq_prep+0x28c/0x300)
>> [ 1903.129549] r7:00000008 r6:ad07f1b0 r5:835e2400 r4:835e0430
>> [ 1903.135284] [<80268988>] (mmc_blk_rw_rq_prep+0x0/0x300) from [<802699a8>] (mmc_blk_issue_rw_rq+0x94/0x42c)
>> [ 1903.145000] [<80269914>] (mmc_blk_issue_rw_rq+0x0/0x42c) from [<8026a210>] (mmc_blk_issue_rq+0x4d0/0x500)
>> [ 1903.154630] [<80269d40>] (mmc_blk_issue_rq+0x0/0x500) from [<8026a89c>] (mmc_queue_thread+0xe0/0x17c)
>> [ 1903.163918] [<8026a7bc>] (mmc_queue_thread+0x0/0x17c) from [<80042490>] (kthread+0xb4/0xc0)
>> [ 1903.172334] [<800423dc>] (kthread+0x0/0xc0) from [<8000d9b8>] (ret_from_fork+0x14/0x3c)
>> [ 1903.180391] r7:00000000 r6:00000000 r5:800423dc r4:ac099c28
>> [ 1903.186119] Code: e5850000 e5953000 e5942000 e5941008 (e5930000)
>> [ 1903.223378] ---[ end trace e1837878f627d738 ]---
>> [ 1903.249775] Kernel panic - not syncing: Fatal exception
>> [ 1903.255074] Rebooting in 1 seconds..
>>
>> On analysis i found that error handling in mmc_init_queue during
>> allocation of bounce buffers is incomplete. In the exception case the
>> allocation of current bounce buffer fails and the previous bounce
>> buffer allocation succeeds. This later leads to exception in,
>> __blk_segment_map_sg while trying to access the bounce buffer.
>>
>> The attached patch improves the error handling during allocation of
>> bounce buffers. The previous bounce buffer is allocated only if the
>> allocation of current bounce buffer succeeds.
>
> You shouldn't send patches as attachments. We need to be able to
> review them and we do that by replying to your email.
>
> Please have a look at Documentation/SubmittingPatches.
>
> Kind regards
> Uffe
>
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