sparc64: Convert NGcopy_{from,to}_user to accurate exception reporting. - net-next.git

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author	David S. Miller <davem@davemloft.net>	2016-10-24 19:32:12 -0700
committer	David S. Miller <davem@davemloft.net>	2016-10-24 19:32:12 -0700
commit	7ae3aaf53f1695877ccd5ebbc49ea65991e41f1e (patch)
tree	e8c03b1bf27e6822f2f5486b6211573fd17a0b94 /Documentation
parent	95707704800988093a9b9a27e0f2f67f5b4bf2fa (diff)

sparc64: Convert NGcopy_{from,to}_user to accurate exception reporting.

Report the exact number of bytes which have not been successfully copied when an exception occurs, using the running remaining length. Signed-off-by: David S. Miller <davem@davemloft.net>

Diffstat (limited to 'Documentation')

0 files changed, 0 insertions, 0 deletions

lock, flags) at pl330_free_chan_resources:2236; 2. call to function `pl330_release_channel' immediately after; 3. call to function `dma_pl330_rqcb' in line 1753; 4. spin_lock_irqsave(pch->lock, flags) at dma_pl330_rqcb:1505. I have fixed it as suggested by Marek Szyprowski. First, I have replaced `pch->lock' with `pl330->lock' in functions `pl330_alloc_chan_resources' and `pl330_free_chan_resources'. This avoids the double-lock by acquiring a different lock than `dma_pl330_rqcb'. NOTE that, as a result, `pl330_free_chan_resources' executes `list_splice_tail_init' on `pch->work_list' under lock `pl330->lock', whereas in the rest of the code `pch->work_list' is protected by `pch->lock'. I don't know if this may cause race conditions. Similarly `pch->cyclic' is written by `pl330_alloc_chan_resources' under `pl330->lock' but read by `pl330_tx_submit' under `pch->lock'. Second, I have removed locking from `pl330_request_channel' and `pl330_release_channel' functions. Function `pl330_request_channel' is only called from `pl330_alloc_chan_resources', so the lock is already held. Function `pl330_release_channel' is called from `pl330_free_chan_resources', which already holds the lock, and from `pl330_del'. Function `pl330_del' is called in an error path of `pl330_probe' and at the end of `pl330_remove', but I assume that there cannot be concurrent accesses to the protected data at those points. Signed-off-by: Iago Abal <mail@iagoabal.eu> Reviewed-by: Marek Szyprowski <m.szyprowski@samsung.com> Signed-off-by: Vinod Koul <vinod.koul@intel.com>

Diffstat (limited to 'include/soc/imx')


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