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Message-Id: <20190418084253.903603121@linutronix.de>
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Date:   Thu, 18 Apr 2019 10:41:28 +0200
From:   Thomas Gleixner <tglx@linutronix.de>
To:     LKML <linux-kernel@vger.kernel.org>
Cc:     Josh Poimboeuf <jpoimboe@redhat.com>, x86@kernel.org,
        Andy Lutomirski <luto@kernel.org>,
        Steven Rostedt <rostedt@goodmis.org>,
        Alexander Potapenko <glider@google.com>,
        Dmitry Vyukov <dvyukov@google.com>,
        Andrey Ryabinin <aryabinin@virtuozzo.com>,
        kasan-dev@googlegroups.com, linux-mm@kvack.org,
        Alexey Dobriyan <adobriyan@gmail.com>,
        Andrew Morton <akpm@linux-foundation.org>,
        Pekka Enberg <penberg@kernel.org>,
        David Rientjes <rientjes@google.com>,
        Christoph Lameter <cl@linux.com>,
        Catalin Marinas <catalin.marinas@arm.com>,
        Mike Rapoport <rppt@linux.vnet.ibm.com>,
        Akinobu Mita <akinobu.mita@gmail.com>,
        iommu@lists.linux-foundation.org,
        Robin Murphy <robin.murphy@arm.com>,
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        Marek Szyprowski <m.szyprowski@samsung.com>,
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        David Sterba <dsterba@suse.com>, Chris Mason <clm@fb.com>,
        Josef Bacik <josef@toxicpanda.com>,
        linux-btrfs@vger.kernel.org, dm-devel@redhat.com,
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        Alasdair Kergon <agk@redhat.com>,
        intel-gfx@lists.freedesktop.org,
        Joonas Lahtinen <joonas.lahtinen@linux.intel.com>,
        Maarten Lankhorst <maarten.lankhorst@linux.intel.com>,
        dri-devel@lists.freedesktop.org, David Airlie <airlied@linux.ie>,
        Jani Nikula <jani.nikula@linux.intel.com>,
        Daniel Vetter <daniel@ffwll.ch>,
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        linux-arch@vger.kernel.org
Subject: [patch V2 09/29] mm/kasan: Simplify stacktrace handling
References: <20190418084119.056416939@linutronix.de>
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Sender: linux-kernel-owner@vger.kernel.org
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Replace the indirection through struct stack_trace by using the storage
array based interfaces.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Dmitry Vyukov <dvyukov@google.com>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: kasan-dev@googlegroups.com
Cc: linux-mm@kvack.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");
 	}