[patch V3 09/29] mm/kasan: Simplify stacktrace handling

Thomas Gleixner
2019-04-25T09:45:02Z

Replace the indirection through struct stack_trace by using the storage
array based interfaces.

Signed-off-by: Thomas Gleixner <tglx-hfZtesqFncYOwBW4kG4KsQ@public.gmane.org>
Acked-by: Dmitry Vyukov <dvyukov-hpIqsD4AKlfQT0dZR+AlfA@public.gmane.org>
Acked-by: Andrey Ryabinin <aryabinin-5HdwGun5lf+gSpxsJD1C4w@public.gmane.org>
Cc: Alexander Potapenko <glider-hpIqsD4AKlfQT0dZR+AlfA@public.gmane.org>
Cc: kasan-dev-/JYPxA39Uh5TLH3MbocFFw@public.gmane.org
Cc: linux-mm-Bw31MaZKKs3YtjvyW6yDsg@public.gmane.org
---
mm/kasan/common.c | 30 ++++++++++++------------------
mm/kasan/report.c | 7 ++++---
2 files changed, 16 insertions(+), 21 deletions(-)

--- a/mm/kasan/common.c
+++ b/mm/kasan/common.c
@@ -48,34 +48,28 @@ static inline int in_irqentry_text(unsig
ptr < (unsigned long)&__softirqentry_text_end);
}

-static inline void filter_irq_stacks(struct stack_trace *trace)
+static inline unsigned int filter_irq_stacks(unsigned long *entries,
+ unsigned int nr_entries)
{
- int i;
+ unsigned int i;

- if (!trace->nr_entries)
- return;
- for (i = 0; i < trace->nr_entries; i++)
- if (in_irqentry_text(trace->entries[i])) {
+ for (i = 0; i < nr_entries; i++) {
+ if (in_irqentry_text(entries[i])) {
/* Include the irqentry function into the stack. */
- trace->nr_entries = i + 1;
- break;
+ return i + 1;
}
+ }
+ return nr_entries;
}

static inline depot_stack_handle_t save_stack(gfp_t flags)
{
unsigned long entries[KASAN_STACK_DEPTH];
- struct stack_trace trace = {
- .nr_entries = 0,
- .entries = entries,
- .max_entries = KASAN_STACK_DEPTH,
- .skip = 0
- };
+ unsigned int nr_entries;

- save_stack_trace(&trace);
- filter_irq_stacks(&trace);
-
- return depot_save_stack(&trace, flags);
+ nr_entries = stack_trace_save(entries, ARRAY_SIZE(entries), 0);
+ nr_entries = filter_irq_stacks(entries, nr_entries);
+ return stack_depot_save(entries, nr_entries, flags);
}

static inline void set_track(struct kasan_track *track, gfp_t flags)
--- a/mm/kasan/report.c
+++ b/mm/kasan/report.c
@@ -100,10 +100,11 @@ static void print_track(struct kasan_tra
{
pr_err("%s by task %u:\n", prefix, track->pid);
if (track->stack) {
- struct stack_trace trace;
+ unsigned long *entries;
+ unsigned int nr_entries;

- depot_fetch_stack(track->stack, &trace);
- print_stack_trace(&trace, 0);
+ nr_entries = stack_depot_fetch(track->stack, &entries);
+ stack_trace_print(entries, nr_entries, 0);
} else {
pr_err("(stack is not available)\n");
}