From d0b2f91bede3bd5e3d24dd6803e56eee959c1797 Mon Sep 17 00:00:00 2001 From: André Fabian Silva Delgado Date: Thu, 20 Oct 2016 00:10:27 -0300 Subject: Linux-libre 4.8.2-gnu --- kernel/trace/trace_events.c | 219 ++++++-------------------------------------- 1 file changed, 28 insertions(+), 191 deletions(-) (limited to 'kernel/trace/trace_events.c') diff --git a/kernel/trace/trace_events.c b/kernel/trace/trace_events.c index 3d4155892..03c0a48c3 100644 --- a/kernel/trace/trace_events.c +++ b/kernel/trace/trace_events.c @@ -15,7 +15,6 @@ #include #include #include -#include #include #include #include @@ -262,6 +261,14 @@ void *trace_event_buffer_reserve(struct trace_event_buffer *fbuffer, local_save_flags(fbuffer->flags); fbuffer->pc = preempt_count(); + /* + * If CONFIG_PREEMPT is enabled, then the tracepoint itself disables + * preemption (adding one to the preempt_count). Since we are + * interested in the preempt_count at the time the tracepoint was + * hit, we need to subtract one to offset the increment. + */ + if (IS_ENABLED(CONFIG_PREEMPT)) + fbuffer->pc--; fbuffer->trace_file = trace_file; fbuffer->event = @@ -499,60 +506,6 @@ static void ftrace_clear_events(struct trace_array *tr) mutex_unlock(&event_mutex); } -/* Shouldn't this be in a header? */ -extern int pid_max; - -/* Returns true if found in filter */ -static bool -find_filtered_pid(struct trace_pid_list *filtered_pids, pid_t search_pid) -{ - /* - * If pid_max changed after filtered_pids was created, we - * by default ignore all pids greater than the previous pid_max. - */ - if (search_pid >= filtered_pids->pid_max) - return false; - - return test_bit(search_pid, filtered_pids->pids); -} - -static bool -ignore_this_task(struct trace_pid_list *filtered_pids, struct task_struct *task) -{ - /* - * Return false, because if filtered_pids does not exist, - * all pids are good to trace. - */ - if (!filtered_pids) - return false; - - return !find_filtered_pid(filtered_pids, task->pid); -} - -static void filter_add_remove_task(struct trace_pid_list *pid_list, - struct task_struct *self, - struct task_struct *task) -{ - if (!pid_list) - return; - - /* For forks, we only add if the forking task is listed */ - if (self) { - if (!find_filtered_pid(pid_list, self->pid)) - return; - } - - /* Sorry, but we don't support pid_max changing after setting */ - if (task->pid >= pid_list->pid_max) - return; - - /* "self" is set for forks, and NULL for exits */ - if (self) - set_bit(task->pid, pid_list->pids); - else - clear_bit(task->pid, pid_list->pids); -} - static void event_filter_pid_sched_process_exit(void *data, struct task_struct *task) { @@ -560,7 +513,7 @@ event_filter_pid_sched_process_exit(void *data, struct task_struct *task) struct trace_array *tr = data; pid_list = rcu_dereference_sched(tr->filtered_pids); - filter_add_remove_task(pid_list, NULL, task); + trace_filter_add_remove_task(pid_list, NULL, task); } static void @@ -572,7 +525,7 @@ event_filter_pid_sched_process_fork(void *data, struct trace_array *tr = data; pid_list = rcu_dereference_sched(tr->filtered_pids); - filter_add_remove_task(pid_list, self, task); + trace_filter_add_remove_task(pid_list, self, task); } void trace_event_follow_fork(struct trace_array *tr, bool enable) @@ -600,8 +553,8 @@ event_filter_pid_sched_switch_probe_pre(void *data, bool preempt, pid_list = rcu_dereference_sched(tr->filtered_pids); this_cpu_write(tr->trace_buffer.data->ignore_pid, - ignore_this_task(pid_list, prev) && - ignore_this_task(pid_list, next)); + trace_ignore_this_task(pid_list, prev) && + trace_ignore_this_task(pid_list, next)); } static void @@ -614,7 +567,7 @@ event_filter_pid_sched_switch_probe_post(void *data, bool preempt, pid_list = rcu_dereference_sched(tr->filtered_pids); this_cpu_write(tr->trace_buffer.data->ignore_pid, - ignore_this_task(pid_list, next)); + trace_ignore_this_task(pid_list, next)); } static void @@ -630,7 +583,7 @@ event_filter_pid_sched_wakeup_probe_pre(void *data, struct task_struct *task) pid_list = rcu_dereference_sched(tr->filtered_pids); this_cpu_write(tr->trace_buffer.data->ignore_pid, - ignore_this_task(pid_list, task)); + trace_ignore_this_task(pid_list, task)); } static void @@ -647,7 +600,7 @@ event_filter_pid_sched_wakeup_probe_post(void *data, struct task_struct *task) /* Set tracing if current is enabled */ this_cpu_write(tr->trace_buffer.data->ignore_pid, - ignore_this_task(pid_list, current)); + trace_ignore_this_task(pid_list, current)); } static void __ftrace_clear_event_pids(struct trace_array *tr) @@ -685,8 +638,7 @@ static void __ftrace_clear_event_pids(struct trace_array *tr) /* Wait till all users are no longer using pid filtering */ synchronize_sched(); - vfree(pid_list->pids); - kfree(pid_list); + trace_free_pid_list(pid_list); } static void ftrace_clear_event_pids(struct trace_array *tr) @@ -1034,18 +986,8 @@ p_next(struct seq_file *m, void *v, loff_t *pos) { struct trace_array *tr = m->private; struct trace_pid_list *pid_list = rcu_dereference_sched(tr->filtered_pids); - unsigned long pid = (unsigned long)v; - - (*pos)++; - - /* pid already is +1 of the actual prevous bit */ - pid = find_next_bit(pid_list->pids, pid_list->pid_max, pid); - /* Return pid + 1 to allow zero to be represented */ - if (pid < pid_list->pid_max) - return (void *)(pid + 1); - - return NULL; + return trace_pid_next(pid_list, v, pos); } static void *p_start(struct seq_file *m, loff_t *pos) @@ -1053,8 +995,6 @@ static void *p_start(struct seq_file *m, loff_t *pos) { struct trace_pid_list *pid_list; struct trace_array *tr = m->private; - unsigned long pid; - loff_t l = 0; /* * Grab the mutex, to keep calls to p_next() having the same @@ -1070,15 +1010,7 @@ static void *p_start(struct seq_file *m, loff_t *pos) if (!pid_list) return NULL; - pid = find_first_bit(pid_list->pids, pid_list->pid_max); - if (pid >= pid_list->pid_max) - return NULL; - - /* Return pid + 1 so that zero can be the exit value */ - for (pid++; pid && l < *pos; - pid = (unsigned long)p_next(m, (void *)pid, &l)) - ; - return (void *)pid; + return trace_pid_start(pid_list, pos); } static void p_stop(struct seq_file *m, void *p) @@ -1088,14 +1020,6 @@ static void p_stop(struct seq_file *m, void *p) mutex_unlock(&event_mutex); } -static int p_show(struct seq_file *m, void *v) -{ - unsigned long pid = (unsigned long)v - 1; - - seq_printf(m, "%lu\n", pid); - return 0; -} - static ssize_t event_enable_read(struct file *filp, char __user *ubuf, size_t cnt, loff_t *ppos) @@ -1654,7 +1578,7 @@ static void ignore_task_cpu(void *data) mutex_is_locked(&event_mutex)); this_cpu_write(tr->trace_buffer.data->ignore_pid, - ignore_this_task(pid_list, current)); + trace_ignore_this_task(pid_list, current)); } static ssize_t @@ -1666,13 +1590,7 @@ ftrace_event_pid_write(struct file *filp, const char __user *ubuf, struct trace_pid_list *filtered_pids = NULL; struct trace_pid_list *pid_list; struct trace_event_file *file; - struct trace_parser parser; - unsigned long val; - loff_t this_pos; - ssize_t read = 0; - ssize_t ret = 0; - pid_t pid; - int nr_pids = 0; + ssize_t ret; if (!cnt) return 0; @@ -1681,93 +1599,15 @@ ftrace_event_pid_write(struct file *filp, const char __user *ubuf, if (ret < 0) return ret; - if (trace_parser_get_init(&parser, EVENT_BUF_SIZE + 1)) - return -ENOMEM; - mutex_lock(&event_mutex); + filtered_pids = rcu_dereference_protected(tr->filtered_pids, lockdep_is_held(&event_mutex)); - /* - * Always recreate a new array. The write is an all or nothing - * operation. Always create a new array when adding new pids by - * the user. If the operation fails, then the current list is - * not modified. - */ - pid_list = kmalloc(sizeof(*pid_list), GFP_KERNEL); - if (!pid_list) { - read = -ENOMEM; - goto out; - } - pid_list->pid_max = READ_ONCE(pid_max); - /* Only truncating will shrink pid_max */ - if (filtered_pids && filtered_pids->pid_max > pid_list->pid_max) - pid_list->pid_max = filtered_pids->pid_max; - pid_list->pids = vzalloc((pid_list->pid_max + 7) >> 3); - if (!pid_list->pids) { - kfree(pid_list); - read = -ENOMEM; - goto out; - } - if (filtered_pids) { - /* copy the current bits to the new max */ - pid = find_first_bit(filtered_pids->pids, - filtered_pids->pid_max); - while (pid < filtered_pids->pid_max) { - set_bit(pid, pid_list->pids); - pid = find_next_bit(filtered_pids->pids, - filtered_pids->pid_max, - pid + 1); - nr_pids++; - } - } - - while (cnt > 0) { - - this_pos = 0; - - ret = trace_get_user(&parser, ubuf, cnt, &this_pos); - if (ret < 0 || !trace_parser_loaded(&parser)) - break; - - read += ret; - ubuf += ret; - cnt -= ret; - - parser.buffer[parser.idx] = 0; - - ret = -EINVAL; - if (kstrtoul(parser.buffer, 0, &val)) - break; - if (val >= pid_list->pid_max) - break; - - pid = (pid_t)val; - - set_bit(pid, pid_list->pids); - nr_pids++; - - trace_parser_clear(&parser); - ret = 0; - } - trace_parser_put(&parser); - - if (ret < 0) { - vfree(pid_list->pids); - kfree(pid_list); - read = ret; + ret = trace_pid_write(filtered_pids, &pid_list, ubuf, cnt); + if (ret < 0) goto out; - } - if (!nr_pids) { - /* Cleared the list of pids */ - vfree(pid_list->pids); - kfree(pid_list); - read = ret; - if (!filtered_pids) - goto out; - pid_list = NULL; - } rcu_assign_pointer(tr->filtered_pids, pid_list); list_for_each_entry(file, &tr->events, list) { @@ -1776,10 +1616,8 @@ ftrace_event_pid_write(struct file *filp, const char __user *ubuf, if (filtered_pids) { synchronize_sched(); - - vfree(filtered_pids->pids); - kfree(filtered_pids); - } else { + trace_free_pid_list(filtered_pids); + } else if (pid_list) { /* * Register a probe that is called before all other probes * to set ignore_pid if next or prev do not match. @@ -1817,9 +1655,8 @@ ftrace_event_pid_write(struct file *filp, const char __user *ubuf, out: mutex_unlock(&event_mutex); - ret = read; - if (read > 0) - *ppos += read; + if (ret > 0) + *ppos += ret; return ret; } @@ -1846,7 +1683,7 @@ static const struct seq_operations show_set_event_seq_ops = { static const struct seq_operations show_set_pid_seq_ops = { .start = p_start, .next = p_next, - .show = p_show, + .show = trace_pid_show, .stop = p_stop, }; -- cgit v1.2.3-54-g00ecf