mm/kasan: Simplify stacktrace handling

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

Signed-off-by: Thomas Gleixner <[email protected]>
Reviewed-by: Josh Poimboeuf <[email protected]>
Acked-by: Dmitry Vyukov <[email protected]>
Acked-by: Andrey Ryabinin <[email protected]>
Cc: Andy Lutomirski <[email protected]>
Cc: Alexander Potapenko <[email protected]>
Cc: [email protected]
Cc: [email protected]
Cc: Steven Rostedt <[email protected]>
Cc: Alexey Dobriyan <[email protected]>
Cc: Andrew Morton <[email protected]>
Cc: Christoph Lameter <[email protected]>
Cc: Pekka Enberg <[email protected]>
Cc: David Rientjes <[email protected]>
Cc: Catalin Marinas <[email protected]>
Cc: Mike Rapoport <[email protected]>
Cc: Akinobu Mita <[email protected]>
Cc: Christoph Hellwig <[email protected]>
Cc: [email protected]
Cc: Robin Murphy <[email protected]>
Cc: Marek Szyprowski <[email protected]>
Cc: Johannes Thumshirn <[email protected]>
Cc: David Sterba <[email protected]>
Cc: Chris Mason <[email protected]>
Cc: Josef Bacik <[email protected]>
Cc: [email protected]
Cc: [email protected]
Cc: Mike Snitzer <[email protected]>
Cc: Alasdair Kergon <[email protected]>
Cc: Daniel Vetter <[email protected]>
Cc: [email protected]
Cc: Joonas Lahtinen <[email protected]>
Cc: Maarten Lankhorst <[email protected]>
Cc: [email protected]
Cc: David Airlie <[email protected]>
Cc: Jani Nikula <[email protected]>
Cc: Rodrigo Vivi <[email protected]>
Cc: Tom Zanussi <[email protected]>
Cc: Miroslav Benes <[email protected]>
Cc: [email protected]
Link: https://lkml.kernel.org/r/[email protected]

mm/kasan/common.c

@@ -48,34 +48,28 @@ static inline int in_irqentry_text(unsigned long ptr)
 		 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
-	};
-
-	save_stack_trace(&trace);
-	filter_irq_stacks(&trace);
+	unsigned int nr_entries;
 
-	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)

mm/kasan/report.c

@@ -100,10 +100,11 @@ static void print_track(struct kasan_track *track, const char *prefix)
 {
 	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");
 	}