diff options
Diffstat (limited to 'kernel/trace/trace.c')
| -rw-r--r-- | kernel/trace/trace.c | 105 |
1 files changed, 95 insertions, 10 deletions
diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c index 14318ce92b13..ab9db750dd29 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -87,7 +87,7 @@ dummy_set_flag(struct trace_array *tr, u32 old_flags, u32 bit, int set) * tracing is active, only save the comm when a trace event * occurred. */ -static DEFINE_PER_CPU(bool, trace_cmdline_save); +static DEFINE_PER_CPU(bool, trace_taskinfo_save); /* * Kill all tracing for good (never come back). @@ -790,7 +790,7 @@ EXPORT_SYMBOL_GPL(tracing_on); static __always_inline void __buffer_unlock_commit(struct ring_buffer *buffer, struct ring_buffer_event *event) { - __this_cpu_write(trace_cmdline_save, true); + __this_cpu_write(trace_taskinfo_save, true); /* If this is the temp buffer, we need to commit fully */ if (this_cpu_read(trace_buffered_event) == event) { @@ -1709,6 +1709,8 @@ void tracing_reset_all_online_cpus(void) } } +static int *tgid_map; + #define SAVED_CMDLINES_DEFAULT 128 #define NO_CMDLINE_MAP UINT_MAX static arch_spinlock_t trace_cmdline_lock = __ARCH_SPIN_LOCK_UNLOCKED; @@ -1722,7 +1724,7 @@ struct saved_cmdlines_buffer { static struct saved_cmdlines_buffer *savedcmd; /* temporary disable recording */ -static atomic_t trace_record_cmdline_disabled __read_mostly; +static atomic_t trace_record_taskinfo_disabled __read_mostly; static inline char *get_saved_cmdlines(int idx) { @@ -1990,16 +1992,87 @@ void trace_find_cmdline(int pid, char comm[]) preempt_enable(); } -void tracing_record_cmdline(struct task_struct *tsk) +int trace_find_tgid(int pid) +{ + if (unlikely(!tgid_map || !pid || pid > PID_MAX_DEFAULT)) + return 0; + + return tgid_map[pid]; +} + +static int trace_save_tgid(struct task_struct *tsk) { - if (atomic_read(&trace_record_cmdline_disabled) || !tracing_is_on()) + if (unlikely(!tgid_map || !tsk->pid || tsk->pid > PID_MAX_DEFAULT)) + return 0; + + tgid_map[tsk->pid] = tsk->tgid; + return 1; +} + +static bool tracing_record_taskinfo_skip(int flags) +{ + if (unlikely(!(flags & (TRACE_RECORD_CMDLINE | TRACE_RECORD_TGID)))) + return true; + if (atomic_read(&trace_record_taskinfo_disabled) || !tracing_is_on()) + return true; + if (!__this_cpu_read(trace_taskinfo_save)) + return true; + return false; +} + +/** + * tracing_record_taskinfo - record the task info of a task + * + * @task - task to record + * @flags - TRACE_RECORD_CMDLINE for recording comm + * - TRACE_RECORD_TGID for recording tgid + */ +void tracing_record_taskinfo(struct task_struct *task, int flags) +{ + if (tracing_record_taskinfo_skip(flags)) + return; + if ((flags & TRACE_RECORD_CMDLINE) && !trace_save_cmdline(task)) + return; + if ((flags & TRACE_RECORD_TGID) && !trace_save_tgid(task)) return; - if (!__this_cpu_read(trace_cmdline_save)) + __this_cpu_write(trace_taskinfo_save, false); +} + +/** + * tracing_record_taskinfo_sched_switch - record task info for sched_switch + * + * @prev - previous task during sched_switch + * @next - next task during sched_switch + * @flags - TRACE_RECORD_CMDLINE for recording comm + * TRACE_RECORD_TGID for recording tgid + */ +void tracing_record_taskinfo_sched_switch(struct task_struct *prev, + struct task_struct *next, int flags) +{ + if (tracing_record_taskinfo_skip(flags)) return; - if (trace_save_cmdline(tsk)) - __this_cpu_write(trace_cmdline_save, false); + if ((flags & TRACE_RECORD_CMDLINE) && + (!trace_save_cmdline(prev) || !trace_save_cmdline(next))) + return; + + if ((flags & TRACE_RECORD_TGID) && + (!trace_save_tgid(prev) || !trace_save_tgid(next))) + return; + + __this_cpu_write(trace_taskinfo_save, false); +} + +/* Helpers to record a specific task information */ +void tracing_record_cmdline(struct task_struct *task) +{ + tracing_record_taskinfo(task, TRACE_RECORD_CMDLINE); +} + +void tracing_record_tgid(struct task_struct *task) +{ + tracing_record_taskinfo(task, TRACE_RECORD_TGID); } /* @@ -3144,7 +3217,7 @@ static void *s_start(struct seq_file *m, loff_t *pos) #endif if (!iter->snapshot) - atomic_inc(&trace_record_cmdline_disabled); + atomic_inc(&trace_record_taskinfo_disabled); if (*pos != iter->pos) { iter->ent = NULL; @@ -3189,7 +3262,7 @@ static void s_stop(struct seq_file *m, void *p) #endif if (!iter->snapshot) - atomic_dec(&trace_record_cmdline_disabled); + atomic_dec(&trace_record_taskinfo_disabled); trace_access_unlock(iter->cpu_file); trace_event_read_unlock(); @@ -4236,6 +4309,18 @@ int set_tracer_flag(struct trace_array *tr, unsigned int mask, int enabled) if (mask == TRACE_ITER_RECORD_CMD) trace_event_enable_cmd_record(enabled); + if (mask == TRACE_ITER_RECORD_TGID) { + if (!tgid_map) + tgid_map = kzalloc((PID_MAX_DEFAULT + 1) * sizeof(*tgid_map), + GFP_KERNEL); + if (!tgid_map) { + tr->trace_flags &= ~TRACE_ITER_RECORD_TGID; + return -ENOMEM; + } + + trace_event_enable_tgid_record(enabled); + } + if (mask == TRACE_ITER_EVENT_FORK) trace_event_follow_fork(tr, enabled); |