lib, stackdepot: add helper to print stack entries

To print a stack entries, users of stackdepot, first use stack_depot_fetch
to get a list of stack entries and then use stack_trace_print to print
this list.  Provide a helper in stackdepot to print stack entries based on
stackdepot handle.  Also change above mentioned users to use this helper.

Link: https://lkml.kernel.org/r/20210915014806.3206938-3-imran.f.khan@oracle.com
Signed-off-by: Imran Khan <imran.f.khan@oracle.com>
Suggested-by: Vlastimil Babka <vbabka@suse.cz>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Reviewed-by: Alexander Potapenko <glider@google.com>
Cc: Andrey Konovalov <andreyknvl@gmail.com>
Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com>
Cc: Daniel Vetter <daniel@ffwll.ch>
Cc: David Airlie <airlied@linux.ie>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Cc: Maxime Ripard <mripard@kernel.org>
Cc: Thomas Zimmermann <tzimmermann@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 4 insertions, 9 deletions

diff --git a/mm/page_owner.c b/mm/page_owner.c
index 62402d22539b..eff29be1218b 100644
--- a/mm/page_owner.c
+++ b/mm/page_owner.c
@@ -394,8 +394,6 @@ void __dump_page_owner(const struct page *page)
 	struct page_ext *page_ext = lookup_page_ext(page);
 	struct page_owner *page_owner;
 	depot_stack_handle_t handle;
-	unsigned long *entries;
-	unsigned int nr_entries;
 	gfp_t gfp_mask;
 	int mt;
 
@@ -423,20 +421,17 @@ void __dump_page_owner(const struct page *page)
 		 page_owner->pid, page_owner->ts_nsec, page_owner->free_ts_nsec);
 
 	handle = READ_ONCE(page_owner->handle);
-	if (!handle) {
+	if (!handle)
 		pr_alert("page_owner allocation stack trace missing\n");
-	} else {
-		nr_entries = stack_depot_fetch(handle, &entries);
-		stack_trace_print(entries, nr_entries, 0);
-	}
+	else
+		stack_depot_print(handle);
 
 	handle = READ_ONCE(page_owner->free_handle);
 	if (!handle) {
 		pr_alert("page_owner free stack trace missing\n");
 	} else {
-		nr_entries = stack_depot_fetch(handle, &entries);
 		pr_alert("page last free stack trace:\n");
-		stack_trace_print(entries, nr_entries, 0);
+		stack_depot_print(handle);
 	}
 
 	if (page_owner->last_migrate_reason != -1)