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| author | Maninder Singh <maninder1.s@samsung.com> | 2018-03-29 02:01:05 +0300 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2018-03-29 02:42:05 +0300 |
| commit | 299815a4fba9f3c7a81434dba0072148f1690608 (patch) | |
| tree | 3475fab8b3c15a02296315de07f13ff16f09da50 /mm | |
| parent | 3d942ee079b917b24e2a0c5f18d35ac8ec9fee48 (diff) | |
| download | linux-299815a4fba9f3c7a81434dba0072148f1690608.tar.xz | |
mm/page_owner: fix recursion bug after changing skip entries
This patch fixes commit 5f48f0bd4e36 ("mm, page_owner: skip unnecessary
stack_trace entries").
Because if we skip first two entries then logic of checking count value
as 2 for recursion is broken and code will go in one depth recursion.
so we need to check only one call of _RET_IP(__set_page_owner) while
checking for recursion.
Current Backtrace while checking for recursion:-
(save_stack) from (__set_page_owner) // (But recursion returns true here)
(__set_page_owner) from (get_page_from_freelist)
(get_page_from_freelist) from (__alloc_pages_nodemask)
(__alloc_pages_nodemask) from (depot_save_stack)
(depot_save_stack) from (save_stack) // recursion should return true here
(save_stack) from (__set_page_owner)
(__set_page_owner) from (get_page_from_freelist)
(get_page_from_freelist) from (__alloc_pages_nodemask+)
(__alloc_pages_nodemask) from (depot_save_stack)
(depot_save_stack) from (save_stack)
(save_stack) from (__set_page_owner)
(__set_page_owner) from (get_page_from_freelist)
Correct Backtrace with fix:
(save_stack) from (__set_page_owner) // recursion returned true here
(__set_page_owner) from (get_page_from_freelist)
(get_page_from_freelist) from (__alloc_pages_nodemask+)
(__alloc_pages_nodemask) from (depot_save_stack)
(depot_save_stack) from (save_stack)
(save_stack) from (__set_page_owner)
(__set_page_owner) from (get_page_from_freelist)
Link: http://lkml.kernel.org/r/1521607043-34670-1-git-send-email-maninder1.s@samsung.com
Fixes: 5f48f0bd4e36 ("mm, page_owner: skip unnecessary stack_trace entries")
Signed-off-by: Maninder Singh <maninder1.s@samsung.com>
Signed-off-by: Vaneet Narang <v.narang@samsung.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Oscar Salvador <osalvador@techadventures.net>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Ayush Mittal <ayush.m@samsung.com>
Cc: Prakash Gupta <guptap@codeaurora.org>
Cc: Vinayak Menon <vinmenon@codeaurora.org>
Cc: Vasyl Gomonovych <gomonovych@gmail.com>
Cc: Amit Sahrawat <a.sahrawat@samsung.com>
Cc: <pankaj.m@samsung.com>
Cc: Vaneet Narang <v.narang@samsung.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'mm')
| -rw-r--r-- | mm/page_owner.c | 6 |
1 files changed, 3 insertions, 3 deletions
diff --git a/mm/page_owner.c b/mm/page_owner.c index 9886c6073828..7172e0a80e13 100644 --- a/mm/page_owner.c +++ b/mm/page_owner.c @@ -123,13 +123,13 @@ void __reset_page_owner(struct page *page, unsigned int order) static inline bool check_recursive_alloc(struct stack_trace *trace, unsigned long ip) { - int i, count; + int i; if (!trace->nr_entries) return false; - for (i = 0, count = 0; i < trace->nr_entries; i++) { - if (trace->entries[i] == ip && ++count == 2) + for (i = 0; i < trace->nr_entries; i++) { + if (trace->entries[i] == ip) return true; } |