/* * debugfs file to track time spent in suspend * * Copyright (c) 2011, Google, Inc. * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by * the Free Software Foundation; either version 2 of the License, or * (at your option) any later version. * * This program is distributed in the hope that 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. */ #include #include #include #include #include #include #include "timekeeping_internal.h" #define NUM_BINS 32 static unsigned int sleep_time_bin[NUM_BINS] = {0}; static int tk_debug_show_sleep_time(struct seq_file *s, void *data) { unsigned int bin; seq_puts(s, " time (secs) count\n"); seq_puts(s, "------------------------------\n"); for (bin = 0; bin < 32; bin++) { if (sleep_time_bin[bin] == 0) continue; seq_printf(s, "%10u - %-10u %4u\n", bin ? 1 << (bin - 1) : 0, 1 << bin, sleep_time_bin[bin]); } return 0; } static int tk_debug_sleep_time_open(struct inode *inode, struct file *file) { return single_open(file, tk_debug_show_sleep_time, NULL); } static const struct file_operations tk_debug_sleep_time_fops = { .open = tk_debug_sleep_time_open, .read = seq_read, .llseek = seq_lseek, .release = single_release, }; static int __init tk_debug_sleep_time_init(void) { struct dentry *d; d = debugfs_create_file("sleep_time", 0444, NULL, NULL, &tk_debug_sleep_time_fops); if (!d) { pr_err("Failed to create sleep_time debug file\n"); return -ENOMEM; } return 0; } late_initcall(tk_debug_sleep_time_init); void tk_debug_account_sleep_time(struct timespec64 *t) { /* Cap bin index so we don't overflow the array */ int bin = min(fls(t->tv_sec), NUM_BINS-1); sleep_time_bin[bin]++; pr_info("Suspended for %lld.%03lu seconds\n", (s64)t->tv_sec, t->tv_nsec / NSEC_PER_MSEC); } 5414e54bf1a'>commitdiff
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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 /include/net/net_namespace.h
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 'include/net/net_namespace.h')