/* * thread-stack.h: Synthesize a thread's stack using call / return events * Copyright (c) 2014, Intel Corporation. * * This program is free software; you can redistribute it and/or modify it * under the terms and conditions of the GNU General Public License, * version 2, as published by the Free Software Foundation. * * This program is distributed in the hope it will be useful, but WITHOUT * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for * more details. * */ #ifndef __PERF_THREAD_STACK_H #define __PERF_THREAD_STACK_H #include #include struct thread; struct comm; struct ip_callchain; struct symbol; struct dso; struct comm; struct perf_sample; struct addr_location; struct call_path; /* * Call/Return flags. * * CALL_RETURN_NO_CALL: 'return' but no matching 'call' * CALL_RETURN_NO_RETURN: 'call' but no matching 'return' */ enum { CALL_RETURN_NO_CALL = 1 << 0, CALL_RETURN_NO_RETURN = 1 << 1, }; /** * struct call_return - paired call/return information. * @thread: thread in which call/return occurred * @comm: comm in which call/return occurred * @cp: call path * @call_time: timestamp of call (if known) * @return_time: timestamp of return (if known) * @branch_count: number of branches seen between call and return * @call_ref: external reference to 'call' sample (e.g. db_id) * @return_ref: external reference to 'return' sample (e.g. db_id) * @db_id: id used for db-export * @flags: Call/Return flags */ struct call_return { struct thread *thread; struct comm *comm; struct call_path *cp; u64 call_time; u64 return_time; u64 branch_count; u64 call_ref; u64 return_ref; u64 db_id; u32 flags; }; /** * struct call_return_processor - provides a call-back to consume call-return * information. * @cpr: call path root * @process: call-back that accepts call/return information * @data: anonymous data for call-back */ struct call_return_processor { struct call_path_root *cpr; int (*process)(struct call_return *cr, void *data); void *data; }; int thread_stack__event(struct thread *thread, u32 flags, u64 from_ip, u64 to_ip, u16 insn_len, u64 trace_nr); void thread_stack__set_trace_nr(struct thread *thread, u64 trace_nr); void thread_stack__sample(struct thread *thread, struct ip_callchain *chain, size_t sz, u64 ip); int thread_stack__flush(struct thread *thread); void thread_stack__free(struct thread *thread); size_t thread_stack__depth(struct thread *thread); struct call_return_processor * call_return_processor__new(int (*process)(struct call_return *cr, void *data), void *data); void call_return_processor__free(struct call_return_processor *crp); int thread_stack__process(struct thread *thread, struct comm *comm, struct perf_sample *sample, struct addr_location *from_al, struct addr_location *to_al, u64 ref, struct call_return_processor *crp); #endif 9eb1fda2d530d3b268eef542c5414e54bf1a'>gus/gusmax.c
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authorIago Abal <mail@iagoabal.eu>2017-01-11 14:00:21 +0100
committerVinod Koul <vinod.koul@intel.com>2017-01-25 15:35:11 +0530
commit91539eb1fda2d530d3b268eef542c5414e54bf1a (patch)
tree960f5ca6342ad20837aff18aad6e8ecd7da32fd6 /sound/isa/gus/gusmax.c
parent6610d0edf6dc7ee97e46ab3a538a565c79d26199 (diff)
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>
Diffstat (limited to 'sound/isa/gus/gusmax.c')