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

[Thomas Gleixner]

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

Signed-off-by: Thomas Gleixner <tglx at linutronix.de>
Reviewed-by: Alexey Dobriyan <adobriyan at gmail.com>
Cc: Andrew Morton <akpm at 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);