[patch V3 05/29] proc: Simplify task stack retrieval

Thomas Gleixner
2019-04-25T10:01:01Z

Replace the indirection through struct stack_trace with an invocation of
the storage array based interface.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
---
fs/proc/base.c | 14 +++++---------
1 file changed, 5 insertions(+), 9 deletions(-)

--- a/fs/proc/base.c
+++ b/fs/proc/base.c
@@ -407,7 +407,6 @@ static void unlock_trace(struct task_str
static int proc_pid_stack(struct seq_file *m, struct pid_namespace *ns,
struct pid *pid, struct task_struct *task)
{
- struct stack_trace trace;
unsigned long *entries;
int err;

@@ -430,20 +429,17 @@ static int proc_pid_stack(struct seq_fil
if (!entries)
return -ENOMEM;

- trace.nr_entries = 0;
- trace.max_entries = MAX_STACK_TRACE_DEPTH;
- trace.entries = entries;
- trace.skip = 0;
-
err = lock_trace(task);
if (!err) {
- unsigned int i;
+ unsigned int i, nr_entries;

- save_stack_trace_tsk(task, &trace);
+ nr_entries = stack_trace_save_tsk(task, entries,
+ MAX_STACK_TRACE_DEPTH, 0);

- for (i = 0; i < trace.nr_entries; i++) {
+ for (i = 0; i < nr_entries; i++) {
seq_printf(m, "[<0>] %pB\n", (void *)entries[i]);
}
+
unlock_trace(task);
}
kfree(entries);