Merge tag 'qcom-arm64-defconfig-fixes-for-4.13-rc2' of git://git.kernel.org/pub/scm...

[sfrench/cifs-2.6.git] / kernel / trace / trace.c

diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index 948ec32e0c27f9197fda8ca500d584f259d5c217..42b9355033d45d5a7c27bf0606799772e70d7421 100644 (file)
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -1916,7 +1916,11 @@ static int trace_save_cmdline(struct task_struct *tsk)
 {
        unsigned pid, idx;
 
-       if (!tsk->pid || unlikely(tsk->pid > PID_MAX_DEFAULT))
+       /* treat recording of idle task as a success */
+       if (!tsk->pid)
+               return 1;
+
+       if (unlikely(tsk->pid > PID_MAX_DEFAULT))
                return 0;
 
        /*
@@ -2002,7 +2006,11 @@ int trace_find_tgid(int pid)
 
 static int trace_save_tgid(struct task_struct *tsk)
 {
-       if (unlikely(!tgid_map || !tsk->pid || tsk->pid > PID_MAX_DEFAULT))
+       /* treat recording of idle task as a success */
+       if (!tsk->pid)
+               return 1;
+
+       if (unlikely(!tgid_map || tsk->pid > PID_MAX_DEFAULT))
                return 0;
 
        tgid_map[tsk->pid] = tsk->tgid;
@@ -2029,11 +2037,20 @@ static bool tracing_record_taskinfo_skip(int flags)
  */
 void tracing_record_taskinfo(struct task_struct *task, int flags)
 {
+       bool done;
+
        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))
+
+       /*
+        * Record as much task information as possible. If some fail, continue
+        * to try to record the others.
+        */
+       done = !(flags & TRACE_RECORD_CMDLINE) || trace_save_cmdline(task);
+       done &= !(flags & TRACE_RECORD_TGID) || trace_save_tgid(task);
+
+       /* If recording any information failed, retry again soon. */
+       if (!done)
                return;
 
        __this_cpu_write(trace_taskinfo_save, false);
@@ -2050,15 +2067,22 @@ void tracing_record_taskinfo(struct task_struct *task, int flags)
 void tracing_record_taskinfo_sched_switch(struct task_struct *prev,
                                          struct task_struct *next, int flags)
 {
+       bool done;
+
        if (tracing_record_taskinfo_skip(flags))
                return;
 
-       if ((flags & TRACE_RECORD_CMDLINE) &&
-           (!trace_save_cmdline(prev) || !trace_save_cmdline(next)))
-               return;
+       /*
+        * Record as much task information as possible. If some fail, continue
+        * to try to record the others.
+        */
+       done  = !(flags & TRACE_RECORD_CMDLINE) || trace_save_cmdline(prev);
+       done &= !(flags & TRACE_RECORD_CMDLINE) || trace_save_cmdline(next);
+       done &= !(flags & TRACE_RECORD_TGID) || trace_save_tgid(prev);
+       done &= !(flags & TRACE_RECORD_TGID) || trace_save_tgid(next);
 
-       if ((flags & TRACE_RECORD_TGID) &&
-           (!trace_save_tgid(prev) || !trace_save_tgid(next)))
+       /* If recording any information failed, retry again soon. */
+       if (!done)
                return;
 
        __this_cpu_write(trace_taskinfo_save, false);
@@ -3334,14 +3358,23 @@ static void print_func_help_header_irq(struct trace_buffer *buf, struct seq_file
                                       unsigned int flags)
 {
        bool tgid = flags & TRACE_ITER_RECORD_TGID;
-
-       seq_printf(m, "#                          %s  _-----=> irqs-off\n",         tgid ? "          " : "");
-       seq_printf(m, "#                          %s / _----=> need-resched\n",     tgid ? "          " : "");
-       seq_printf(m, "#                          %s| / _---=> hardirq/softirq\n",  tgid ? "          " : "");
-       seq_printf(m, "#                          %s|| / _--=> preempt-depth\n",    tgid ? "          " : "");
-       seq_printf(m, "#                          %s||| /     delay\n",             tgid ? "          " : "");
-       seq_printf(m, "#           TASK-PID   CPU#%s||||    TIMESTAMP  FUNCTION\n", tgid ? "   TGID   " : "");
-       seq_printf(m, "#              | |       | %s||||       |         |\n",      tgid ? "     |    " : "");
+       const char tgid_space[] = "          ";
+       const char space[] = "  ";
+
+       seq_printf(m, "#                          %s  _-----=> irqs-off\n",
+                  tgid ? tgid_space : space);
+       seq_printf(m, "#                          %s / _----=> need-resched\n",
+                  tgid ? tgid_space : space);
+       seq_printf(m, "#                          %s| / _---=> hardirq/softirq\n",
+                  tgid ? tgid_space : space);
+       seq_printf(m, "#                          %s|| / _--=> preempt-depth\n",
+                  tgid ? tgid_space : space);
+       seq_printf(m, "#                          %s||| /     delay\n",
+                  tgid ? tgid_space : space);
+       seq_printf(m, "#           TASK-PID   CPU#%s||||    TIMESTAMP  FUNCTION\n",
+                  tgid ? "   TGID   " : space);
+       seq_printf(m, "#              | |       | %s||||       |         |\n",
+                  tgid ? "     |    " : space);
 }
 
 void
@@ -4689,6 +4722,76 @@ static const struct file_operations tracing_readme_fops = {
        .llseek         = generic_file_llseek,
 };
 
+static void *saved_tgids_next(struct seq_file *m, void *v, loff_t *pos)
+{
+       int *ptr = v;
+
+       if (*pos || m->count)
+               ptr++;
+
+       (*pos)++;
+
+       for (; ptr <= &tgid_map[PID_MAX_DEFAULT]; ptr++) {
+               if (trace_find_tgid(*ptr))
+                       return ptr;
+       }
+
+       return NULL;
+}
+
+static void *saved_tgids_start(struct seq_file *m, loff_t *pos)
+{
+       void *v;
+       loff_t l = 0;
+
+       if (!tgid_map)
+               return NULL;
+
+       v = &tgid_map[0];
+       while (l <= *pos) {
+               v = saved_tgids_next(m, v, &l);
+               if (!v)
+                       return NULL;
+       }
+
+       return v;
+}
+
+static void saved_tgids_stop(struct seq_file *m, void *v)
+{
+}
+
+static int saved_tgids_show(struct seq_file *m, void *v)
+{
+       int pid = (int *)v - tgid_map;
+
+       seq_printf(m, "%d %d\n", pid, trace_find_tgid(pid));
+       return 0;
+}
+
+static const struct seq_operations tracing_saved_tgids_seq_ops = {
+       .start          = saved_tgids_start,
+       .stop           = saved_tgids_stop,
+       .next           = saved_tgids_next,
+       .show           = saved_tgids_show,
+};
+
+static int tracing_saved_tgids_open(struct inode *inode, struct file *filp)
+{
+       if (tracing_disabled)
+               return -ENODEV;
+
+       return seq_open(filp, &tracing_saved_tgids_seq_ops);
+}
+
+
+static const struct file_operations tracing_saved_tgids_fops = {
+       .open           = tracing_saved_tgids_open,
+       .read           = seq_read,
+       .llseek         = seq_lseek,
+       .release        = seq_release,
+};
+
 static void *saved_cmdlines_next(struct seq_file *m, void *v, loff_t *pos)
 {
        unsigned int *ptr = v;
@@ -7671,6 +7774,7 @@ static int instance_rmdir(const char *name)
        }
        kfree(tr->topts);
 
+       free_cpumask_var(tr->tracing_cpumask);
        kfree(tr->name);
        kfree(tr);
 
@@ -7921,6 +8025,9 @@ static __init int tracer_init_tracefs(void)
        trace_create_file("saved_cmdlines_size", 0644, d_tracer,
                          NULL, &tracing_saved_cmdlines_size_fops);
 
+       trace_create_file("saved_tgids", 0444, d_tracer,
+                       NULL, &tracing_saved_tgids_fops);
+
        trace_eval_init();
 
        trace_create_eval_file(d_tracer);