#define NFS4_MAXTAGLEN 20
#define NFS4_enc_cb_null_sz 0
#define NFS4_dec_cb_null_sz 0
#define cb_compound_enc_hdr_sz 4
#define cb_compound_dec_hdr_sz (3 + (NFS4_MAXTAGLEN >> 2))
#define sessionid_sz (NFS4_MAX_SESSIONID_LEN >> 2)
#define cb_sequence_enc_sz (sessionid_sz + 4 + \
1 /* no referring calls list yet */)
#define cb_sequence_dec_sz (op_dec_sz + sessionid_sz + 4)
#define op_enc_sz 1
#define op_dec_sz 2
#define enc_nfs4_fh_sz (1 + (NFS4_FHSIZE >> 2))
#define enc_stateid_sz (NFS4_STATEID_SIZE >> 2)
#define NFS4_enc_cb_recall_sz (cb_compound_enc_hdr_sz + \
cb_sequence_enc_sz + \
1 + enc_stateid_sz + \
enc_nfs4_fh_sz)
#define NFS4_dec_cb_recall_sz (cb_compound_dec_hdr_sz + \
cb_sequence_dec_sz + \
op_dec_sz)
#define NFS4_enc_cb_layout_sz (cb_compound_enc_hdr_sz + \
cb_sequence_enc_sz + \
1 + 3 + \
enc_nfs4_fh_sz + 4)
#define NFS4_dec_cb_layout_sz (cb_compound_dec_hdr_sz + \
cb_sequence_dec_sz + \
op_dec_sz)
#define NFS4_enc_cb_notify_lock_sz (cb_compound_enc_hdr_sz + \
cb_sequence_enc_sz + \
2 + 1 + \
XDR_QUADLEN(NFS4_OPAQUE_LIMIT) + \
enc_nfs4_fh_sz)
#define NFS4_dec_cb_notify_lock_sz (cb_compound_dec_hdr_sz + \
cb_sequence_dec_sz + \
op_dec_sz)
| Tobias Klauser |
dmaengine: pl330: fix double lock
The static bug finder EBA (http://www.iagoabal.eu/eba/) reported the
following double-lock bug:
Double lock:
1. spin_lock_irqsave(pch->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>