/* * tsacct.c - System accounting over taskstats interface * * Copyright (C) Jay Lan, * * * 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 /* * fill in basic accounting fields */ void bacct_add_tsk(struct user_namespace *user_ns, struct pid_namespace *pid_ns, struct taskstats *stats, struct task_struct *tsk) { const struct cred *tcred; cputime_t utime, stime, utimescaled, stimescaled; u64 delta; BUILD_BUG_ON(TS_COMM_LEN < TASK_COMM_LEN); /* calculate task elapsed time in nsec */ delta = ktime_get_ns() - tsk->start_time; /* Convert to micro seconds */ do_div(delta, NSEC_PER_USEC); stats->ac_etime = delta; /* Convert to seconds for btime */ do_div(delta, USEC_PER_SEC); stats->ac_btime = get_seconds() - delta; if (thread_group_leader(tsk)) { stats->ac_exitcode = tsk->exit_code; if (tsk->flags & PF_FORKNOEXEC) stats->ac_flag |= AFORK; } if (tsk->flags & PF_SUPERPRIV) stats->ac_flag |= ASU; if (tsk->flags & PF_DUMPCORE) stats->ac_flag |= ACORE; if (tsk->flags & PF_SIGNALED) stats->ac_flag |= AXSIG; stats->ac_nice = task_nice(tsk); stats->ac_sched = tsk->policy; stats->ac_pid = task_pid_nr_ns(tsk, pid_ns); rcu_read_lock(); tcred = __task_cred(tsk); stats->ac_uid = from_kuid_munged(user_ns, tcred->uid); stats->ac_gid = from_kgid_munged(user_ns, tcred->gid); stats->ac_ppid = pid_alive(tsk) ? task_tgid_nr_ns(rcu_dereference(tsk->real_parent), pid_ns) : 0; rcu_read_unlock(); task_cputime(tsk, &utime, &stime); stats->ac_utime = cputime_to_usecs(utime); stats->ac_stime = cputime_to_usecs(stime); task_cputime_scaled(tsk, &utimescaled, &stimescaled); stats->ac_utimescaled = cputime_to_usecs(utimescaled); stats->ac_stimescaled = cputime_to_usecs(stimescaled); stats->ac_minflt = tsk->min_flt; stats->ac_majflt = tsk->maj_flt; strncpy(stats->ac_comm, tsk->comm, sizeof(stats->ac_comm)); } #ifdef CONFIG_TASK_XACCT #define KB 1024 #define MB (1024*KB) #define KB_MASK (~(KB-1)) /* * fill in extended accounting fields */ void xacct_add_tsk(struct taskstats *stats, struct task_struct *p) { struct mm_struct *mm; /* convert pages-nsec/1024 to Mbyte-usec, see __acct_update_integrals */ stats->coremem = p->acct_rss_mem1 * PAGE_SIZE; do_div(stats->coremem, 1000 * KB); stats->virtmem = p->acct_vm_mem1 * PAGE_SIZE; do_div(stats->virtmem, 1000 * KB); mm = get_task_mm(p); if (mm) { /* adjust to KB unit */ stats->hiwater_rss = get_mm_hiwater_rss(mm) * PAGE_SIZE / KB; stats->hiwater_vm = get_mm_hiwater_vm(mm) * PAGE_SIZE / KB; mmput(mm); } stats->read_char = p->ioac.rchar & KB_MASK; stats->write_char = p->ioac.wchar & KB_MASK; stats->read_syscalls = p->ioac.syscr & KB_MASK; stats->write_syscalls = p->ioac.syscw & KB_MASK; #ifdef CONFIG_TASK_IO_ACCOUNTING stats->read_bytes = p->ioac.read_bytes & KB_MASK; stats->write_bytes = p->ioac.write_bytes & KB_MASK; stats->cancelled_write_bytes = p->ioac.cancelled_write_bytes & KB_MASK; #else stats->read_bytes = 0; stats->write_bytes = 0; stats->cancelled_write_bytes = 0; #endif } #undef KB #undef MB static void __acct_update_integrals(struct task_struct *tsk, cputime_t utime, cputime_t stime) { cputime_t time, dtime; u64 delta; if (!likely(tsk->mm)) return; time = stime + utime; dtime = time - tsk->acct_timexpd; /* Avoid division: cputime_t is often in nanoseconds already. */ delta = cputime_to_nsecs(dtime); if (delta < TICK_NSEC) return; tsk->acct_timexpd = time; /* * Divide by 1024 to avoid overflow, and to avoid division. * The final unit reported to userspace is Mbyte-usecs, * the rest of the math is done in xacct_add_tsk. */ tsk->acct_rss_mem1 += delta * get_mm_rss(tsk->mm) >> 10; tsk->acct_vm_mem1 += delta * tsk->mm->total_vm >> 10; } /** * acct_update_integrals - update mm integral fields in task_struct * @tsk: task_struct for accounting */ void acct_update_integrals(struct task_struct *tsk) { cputime_t utime, stime; unsigned long flags; local_irq_save(flags); task_cputime(tsk, &utime, &stime); __acct_update_integrals(tsk, utime, stime); local_irq_restore(flags); } /** * acct_account_cputime - update mm integral after cputime update * @tsk: task_struct for accounting */ void acct_account_cputime(struct task_struct *tsk) { __acct_update_integrals(tsk, tsk->utime, tsk->stime); } /** * acct_clear_integrals - clear the mm integral fields in task_struct * @tsk: task_struct whose accounting fields are cleared */ void acct_clear_integrals(struct task_struct *tsk) { tsk->acct_timexpd = 0; tsk->acct_rss_mem1 = 0; tsk->acct_vm_mem1 = 0; } #endif ext.git/commit/net/rxrpc/call_accept.c?h=nds-private-remove&id=91539eb1fda2d530d3b268eef542c5414e54bf1a'>91539eb1fda2d530d3b268eef542c5414e54bf1a (patch) tree960f5ca6342ad20837aff18aad6e8ecd7da32fd6 /net/rxrpc/call_accept.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 'net/rxrpc/call_accept.c')