| Message ID | 1409929466-29506-2-git-send-email-k.kozlowski@samsung.com (mailing list archive) |
|---|---|
| State | Superseded |
| Headers | show |
On 09/05/2014 05:04 PM, Krzysztof Kozlowski wrote: > If dma_async_device_register() returns error and probe should clean up > and return error, a NULL pointer exception happens because of > dereference of not allocated channel thread: > [...] > Signed-off-by: Krzysztof Kozlowski <k.kozlowski@samsung.com> Reviewed-by: Lars-Peter Clausen <lars@metafoo.de> -- To unsubscribe from this list: send the line "unsubscribe dmaengine" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/drivers/dma/pl330.c b/drivers/dma/pl330.c index 47d82070848d..04c2f39227f1 100644 --- a/drivers/dma/pl330.c +++ b/drivers/dma/pl330.c @@ -2756,8 +2756,10 @@ probe_err3: list_del(&pch->chan.device_node); /* Flush the channel */ - pl330_control(&pch->chan, DMA_TERMINATE_ALL, 0); - pl330_free_chan_resources(&pch->chan); + if (pch->thread) { + pl330_control(&pch->chan, DMA_TERMINATE_ALL, 0); + pl330_free_chan_resources(&pch->chan); + } } probe_err2: pl330_del(pl330);
If dma_async_device_register() returns error and probe should clean up and return error, a NULL pointer exception happens because of dereference of not allocated channel thread: Dmesg log (from early printk): dma-pl330 12680000.pdma: unable to register DMAC DMA pl330_control: removing pch: eeac4000, chan: eeac4014, thread: (null) Unable to handle kernel NULL pointer dereference at virtual address 0000000c pgd = c0004000 [0000000c] *pgd=00000000 Internal error: Oops: 5 [#1] PREEMPT SMP ARM Modules linked in: CPU: 2 PID: 1 Comm: swapper/0 Not tainted 3.17.0-rc3-next-20140904-00005-g6cc4c1937d90-dirty #427 task: ee80a800 ti: ee888000 task.ti: ee888000 PC is at _stop+0x8/0x2c8 LR is at pl330_control+0x70/0x2e8 pc : [<c0205dc8>] lr : [<c020623c>] psr: 60000193 sp : ee889df8 ip : 00000002 fp : 00000000 r10: eeac4014 r9 : ee0e62bc r8 : 00000000 r7 : eeac405c r6 : 60000113 r5 : ee0e6210 r4 : eeac4000 r3 : 00000002 r2 : 00000002 r1 : 00010000 r0 : 00000000 Flags: nZCv IRQs off FIQs on Mode SVC_32 ISA ARM Segment kernel Control: 10c5387d Table: 4000404a DAC: 00000015 Process swapper/0 (pid: 1, stack limit = 0xee888240) Stack: (0xee889df8 to 0xee88a000) 9de0: 00000002 eeac4000 9e00: ee0e6210 eeac4000 ee0e6210 60000113 eeac405c c020623c 00000000 c020725c 9e20: ee889e20 ee889e20 ee0e6210 eeac4080 00200200 00100100 eeac4014 00000020 9e40: ee0e6218 c0208374 00000000 ee9bb340 ee0e6210 00000000 00000000 c0605cd8 9e60: ee970000 c0605c84 ee9700f8 00000000 c05c4270 00000000 00000000 c0203b3c 9e80: ee970000 c06624a8 00000000 c0605c84 00000000 c023f890 ee970000 c0605c84 9ea0: ee970034 00000000 c05b23d0 c023fa3c 00000000 c0605c84 c023f9b0 c023e0d4 9ec0: ee947e78 ee9b9440 c0605c84 eea1e780 c0605acc c023f094 c0513b50 c0605c84 9ee0: c05ecbd8 c0605c84 c05ecbd8 ee11ba40 c0626500 c0240064 00000000 c05ecbd8 9f00: c05ecbd8 c0008964 c040f13c 0000009f c0626500 c057465c ee80a800 60000113 9f20: 00000000 c05efdb0 60000113 00000000 ef7fc89d c0421168 0000008f c003787c 9f40: c0573d6c 00000006 ef7fc8bb 00000006 c05efd50 ef7fc800 c05dfbc4 00000006 9f60: c05c4264 c0626500 0000008f c05c4270 c059b518 c059bcb4 00000006 00000006 9f80: c059b518 c003c08c 00000000 c040091c 00000000 00000000 00000000 00000000 9fa0: 00000000 c0400924 00000000 c000e7b8 00000000 00000000 00000000 00000000 9fc0: 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 9fe0: 00000000 00000000 00000000 00000000 00000013 00000000 c0c0c0c0 c0c0c0c0 [<c0205dc8>] (_stop) from [<c020623c>] (pl330_control+0x70/0x2e8) [<c020623c>] (pl330_control) from [<c0208374>] (pl330_probe+0x594/0x75c) [<c0208374>] (pl330_probe) from [<c0203b3c>] (amba_probe+0xb8/0x120) [<c0203b3c>] (amba_probe) from [<c023f890>] (driver_probe_device+0x10c/0x22c) [<c023f890>] (driver_probe_device) from [<c023fa3c>] (__driver_attach+0x8c/0x90) [<c023fa3c>] (__driver_attach) from [<c023e0d4>] (bus_for_each_dev+0x54/0x88) [<c023e0d4>] (bus_for_each_dev) from [<c023f094>] (bus_add_driver+0xd4/0x1d0) [<c023f094>] (bus_add_driver) from [<c0240064>] (driver_register+0x78/0xf4) [<c0240064>] (driver_register) from [<c0008964>] (do_one_initcall+0x80/0x1d0) [<c0008964>] (do_one_initcall) from [<c059bcb4>] (kernel_init_freeable+0x108/0x1d4) [<c059bcb4>] (kernel_init_freeable) from [<c0400924>] (kernel_init+0x8/0xec) [<c0400924>] (kernel_init) from [<c000e7b8>] (ret_from_fork+0x14/0x3c) Code: e5813010 e12fff1e e92d40f0 e24dd00c (e590200c) ---[ end trace c94b2f4f38dff3bf ]--- This happens because the necessary resources were not yet allocated - no call to pl330_alloc_chan_resources(). Terminate the thread and free channel resource only if channel thread is not NULL. Signed-off-by: Krzysztof Kozlowski <k.kozlowski@samsung.com> Cc: <stable@vger.kernel.org> Fixes: 0b94c5771705 ("DMA: PL330: Add check if device tree compatible") --- drivers/dma/pl330.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-)