From: Imran Khan <imran.f.khan@xxxxxxxxxx> Subject: 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@xxxxxxxxxx Signed-off-by: Imran Khan <imran.f.khan@xxxxxxxxxx> Suggested-by: Vlastimil Babka <vbabka@xxxxxxx> Acked-by: Vlastimil Babka <vbabka@xxxxxxx> Reviewed-by: Alexander Potapenko <glider@xxxxxxxxxx> Cc: Andrey Konovalov <andreyknvl@xxxxxxxxx> Cc: Andrey Ryabinin <ryabinin.a.a@xxxxxxxxx> Cc: Daniel Vetter <daniel@xxxxxxxx> Cc: David Airlie <airlied@xxxxxxxx> Cc: Dmitry Vyukov <dvyukov@xxxxxxxxxx> Cc: Geert Uytterhoeven <geert@xxxxxxxxxxxxxx> Cc: Maarten Lankhorst <maarten.lankhorst@xxxxxxxxxxxxxxx> Cc: Maxime Ripard <mripard@xxxxxxxxxx> Cc: Thomas Zimmermann <tzimmermann@xxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- include/linux/stackdepot.h | 2 ++ lib/stackdepot.c | 18 ++++++++++++++++++ mm/kasan/report.c | 15 +++------------ mm/page_owner.c | 13 ++++--------- 4 files changed, 27 insertions(+), 21 deletions(-) --- a/include/linux/stackdepot.h~lib-stackdepot-add-helper-to-print-stack-entries +++ a/include/linux/stackdepot.h @@ -25,6 +25,8 @@ depot_stack_handle_t stack_depot_save(un unsigned int stack_depot_fetch(depot_stack_handle_t handle, unsigned long **entries); +void stack_depot_print(depot_stack_handle_t stack); + #ifdef CONFIG_STACKDEPOT int stack_depot_init(void); #else --- a/lib/stackdepot.c~lib-stackdepot-add-helper-to-print-stack-entries +++ a/lib/stackdepot.c @@ -214,6 +214,24 @@ static inline struct stack_record *find_ } /** + * stack_depot_print - print stack entries from a depot + * + * @stack: Stack depot handle which was returned from + * stack_depot_save(). + * + */ +void stack_depot_print(depot_stack_handle_t stack) +{ + unsigned long *entries; + unsigned int nr_entries; + + nr_entries = stack_depot_fetch(stack, &entries); + if (nr_entries > 0) + stack_trace_print(entries, nr_entries, 0); +} +EXPORT_SYMBOL_GPL(stack_depot_print); + +/** * stack_depot_fetch - Fetch stack entries from a depot * * @handle: Stack depot handle which was returned from --- a/mm/kasan/report.c~lib-stackdepot-add-helper-to-print-stack-entries +++ a/mm/kasan/report.c @@ -132,20 +132,11 @@ static void end_report(unsigned long *fl kasan_enable_current(); } -static void print_stack(depot_stack_handle_t stack) -{ - unsigned long *entries; - unsigned int nr_entries; - - nr_entries = stack_depot_fetch(stack, &entries); - stack_trace_print(entries, nr_entries, 0); -} - static void print_track(struct kasan_track *track, const char *prefix) { pr_err("%s by task %u:\n", prefix, track->pid); if (track->stack) { - print_stack(track->stack); + stack_depot_print(track->stack); } else { pr_err("(stack is not available)\n"); } @@ -214,12 +205,12 @@ static void describe_object_stacks(struc return; if (alloc_meta->aux_stack[0]) { pr_err("Last potentially related work creation:\n"); - print_stack(alloc_meta->aux_stack[0]); + stack_depot_print(alloc_meta->aux_stack[0]); pr_err("\n"); } if (alloc_meta->aux_stack[1]) { pr_err("Second to last potentially related work creation:\n"); - print_stack(alloc_meta->aux_stack[1]); + stack_depot_print(alloc_meta->aux_stack[1]); pr_err("\n"); } #endif --- a/mm/page_owner.c~lib-stackdepot-add-helper-to-print-stack-entries +++ a/mm/page_owner.c @@ -394,8 +394,6 @@ void __dump_page_owner(const struct 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_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) _
