[v6,1/4] rcu/kasan: record and print call_rcu() call stack
diff mbox series

Message ID 20200522020059.22332-1-walter-zh.wu@mediatek.com
State New
Headers show
Series
  • kasan: memorize and print call_rcu stack
Related show

Commit Message

Walter Wu May 22, 2020, 2 a.m. UTC
This feature will record the last two call_rcu() call stacks and
prints up to 2 call_rcu() call stacks in KASAN report.

When call_rcu() is called, we store the call_rcu() call stack into
slub alloc meta-data, so that the KASAN report can print rcu stack.

[1]https://bugzilla.kernel.org/show_bug.cgi?id=198437
[2]https://groups.google.com/forum/#!searchin/kasan-dev/better$20stack$20traces$20for$20rcu%7Csort:date/kasan-dev/KQsjT_88hDE/7rNUZprRBgAJ

Signed-off-by: Walter Wu <walter-zh.wu@mediatek.com>
Suggested-by: Dmitry Vyukov <dvyukov@google.com>
Acked-by: Paul E. McKenney <paulmck@kernel.org>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Josh Triplett <josh@joshtriplett.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Lai Jiangshan <jiangshanlai@gmail.com>
Cc: Joel Fernandes <joel@joelfernandes.org>
Cc: Andrey Konovalov <andreyknvl@google.com>
---
 include/linux/kasan.h |  2 ++
 kernel/rcu/tree.c     |  2 ++
 mm/kasan/common.c     |  4 ++--
 mm/kasan/generic.c    | 21 +++++++++++++++++++++
 mm/kasan/kasan.h      | 10 ++++++++++
 mm/kasan/report.c     | 28 +++++++++++++++++++++++-----
 6 files changed, 60 insertions(+), 7 deletions(-)

Comments

Dmitry Vyukov May 25, 2020, 9:56 a.m. UTC | #1
On Fri, May 22, 2020 at 4:01 AM Walter Wu <walter-zh.wu@mediatek.com> wrote:
>
> This feature will record the last two call_rcu() call stacks and
> prints up to 2 call_rcu() call stacks in KASAN report.
>
> When call_rcu() is called, we store the call_rcu() call stack into
> slub alloc meta-data, so that the KASAN report can print rcu stack.
>
> [1]https://bugzilla.kernel.org/show_bug.cgi?id=198437
> [2]https://groups.google.com/forum/#!searchin/kasan-dev/better$20stack$20traces$20for$20rcu%7Csort:date/kasan-dev/KQsjT_88hDE/7rNUZprRBgAJ

Hi Walter,

The series look good to me. Thanks for bearing with me. I am eager to
see this in syzbot reports.

Reviewed-and-tested-by: Dmitry Vyukov <dvyukov@google.com>

> Signed-off-by: Walter Wu <walter-zh.wu@mediatek.com>
> Suggested-by: Dmitry Vyukov <dvyukov@google.com>
> Acked-by: Paul E. McKenney <paulmck@kernel.org>
> Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
> Cc: Dmitry Vyukov <dvyukov@google.com>
> Cc: Alexander Potapenko <glider@google.com>
> Cc: Andrew Morton <akpm@linux-foundation.org>
> Cc: Josh Triplett <josh@joshtriplett.org>
> Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
> Cc: Lai Jiangshan <jiangshanlai@gmail.com>
> Cc: Joel Fernandes <joel@joelfernandes.org>
> Cc: Andrey Konovalov <andreyknvl@google.com>
> ---
>  include/linux/kasan.h |  2 ++
>  kernel/rcu/tree.c     |  2 ++
>  mm/kasan/common.c     |  4 ++--
>  mm/kasan/generic.c    | 21 +++++++++++++++++++++
>  mm/kasan/kasan.h      | 10 ++++++++++
>  mm/kasan/report.c     | 28 +++++++++++++++++++++++-----
>  6 files changed, 60 insertions(+), 7 deletions(-)
>
> diff --git a/include/linux/kasan.h b/include/linux/kasan.h
> index 31314ca7c635..23b7ee00572d 100644
> --- a/include/linux/kasan.h
> +++ b/include/linux/kasan.h
> @@ -174,11 +174,13 @@ static inline size_t kasan_metadata_size(struct kmem_cache *cache) { return 0; }
>
>  void kasan_cache_shrink(struct kmem_cache *cache);
>  void kasan_cache_shutdown(struct kmem_cache *cache);
> +void kasan_record_aux_stack(void *ptr);
>
>  #else /* CONFIG_KASAN_GENERIC */
>
>  static inline void kasan_cache_shrink(struct kmem_cache *cache) {}
>  static inline void kasan_cache_shutdown(struct kmem_cache *cache) {}
> +static inline void kasan_record_aux_stack(void *ptr) {}
>
>  #endif /* CONFIG_KASAN_GENERIC */
>
> diff --git a/kernel/rcu/tree.c b/kernel/rcu/tree.c
> index 06548e2ebb72..36a4ff7f320b 100644
> --- a/kernel/rcu/tree.c
> +++ b/kernel/rcu/tree.c
> @@ -57,6 +57,7 @@
>  #include <linux/slab.h>
>  #include <linux/sched/isolation.h>
>  #include <linux/sched/clock.h>
> +#include <linux/kasan.h>
>  #include "../time/tick-internal.h"
>
>  #include "tree.h"
> @@ -2668,6 +2669,7 @@ __call_rcu(struct rcu_head *head, rcu_callback_t func)
>         head->func = func;
>         head->next = NULL;
>         local_irq_save(flags);
> +       kasan_record_aux_stack(head);
>         rdp = this_cpu_ptr(&rcu_data);
>
>         /* Add the callback to our list. */
> diff --git a/mm/kasan/common.c b/mm/kasan/common.c
> index 2906358e42f0..8bc618289bb1 100644
> --- a/mm/kasan/common.c
> +++ b/mm/kasan/common.c
> @@ -41,7 +41,7 @@
>  #include "kasan.h"
>  #include "../slab.h"
>
> -static inline depot_stack_handle_t save_stack(gfp_t flags)
> +depot_stack_handle_t kasan_save_stack(gfp_t flags)
>  {
>         unsigned long entries[KASAN_STACK_DEPTH];
>         unsigned int nr_entries;
> @@ -54,7 +54,7 @@ static inline depot_stack_handle_t save_stack(gfp_t flags)
>  static inline void set_track(struct kasan_track *track, gfp_t flags)
>  {
>         track->pid = current->pid;
> -       track->stack = save_stack(flags);
> +       track->stack = kasan_save_stack(flags);
>  }
>
>  void kasan_enable_current(void)
> diff --git a/mm/kasan/generic.c b/mm/kasan/generic.c
> index 56ff8885fe2e..8acf48882ba2 100644
> --- a/mm/kasan/generic.c
> +++ b/mm/kasan/generic.c
> @@ -325,3 +325,24 @@ DEFINE_ASAN_SET_SHADOW(f2);
>  DEFINE_ASAN_SET_SHADOW(f3);
>  DEFINE_ASAN_SET_SHADOW(f5);
>  DEFINE_ASAN_SET_SHADOW(f8);
> +
> +void kasan_record_aux_stack(void *addr)
> +{
> +       struct page *page = kasan_addr_to_page(addr);
> +       struct kmem_cache *cache;
> +       struct kasan_alloc_meta *alloc_info;
> +       void *object;
> +
> +       if (!(page && PageSlab(page)))
> +               return;
> +
> +       cache = page->slab_cache;
> +       object = nearest_obj(cache, page, addr);
> +       alloc_info = get_alloc_info(cache, object);
> +
> +       /*
> +        * record the last two call_rcu() call stacks.
> +        */
> +       alloc_info->aux_stack[1] = alloc_info->aux_stack[0];
> +       alloc_info->aux_stack[0] = kasan_save_stack(GFP_NOWAIT);
> +}
> diff --git a/mm/kasan/kasan.h b/mm/kasan/kasan.h
> index e8f37199d885..a7391bc83070 100644
> --- a/mm/kasan/kasan.h
> +++ b/mm/kasan/kasan.h
> @@ -104,7 +104,15 @@ struct kasan_track {
>
>  struct kasan_alloc_meta {
>         struct kasan_track alloc_track;
> +#ifdef CONFIG_KASAN_GENERIC
> +       /*
> +        * call_rcu() call stack is stored into struct kasan_alloc_meta.
> +        * The free stack is stored into struct kasan_free_meta.
> +        */
> +       depot_stack_handle_t aux_stack[2];
> +#else
>         struct kasan_track free_track[KASAN_NR_FREE_STACKS];
> +#endif
>  #ifdef CONFIG_KASAN_SW_TAGS_IDENTIFY
>         u8 free_pointer_tag[KASAN_NR_FREE_STACKS];
>         u8 free_track_idx;
> @@ -159,6 +167,8 @@ void kasan_report_invalid_free(void *object, unsigned long ip);
>
>  struct page *kasan_addr_to_page(const void *addr);
>
> +depot_stack_handle_t kasan_save_stack(gfp_t flags);
> +
>  #if defined(CONFIG_KASAN_GENERIC) && \
>         (defined(CONFIG_SLAB) || defined(CONFIG_SLUB))
>  void quarantine_put(struct kasan_free_meta *info, struct kmem_cache *cache);
> diff --git a/mm/kasan/report.c b/mm/kasan/report.c
> index 80f23c9da6b0..2421a4bd9227 100644
> --- a/mm/kasan/report.c
> +++ b/mm/kasan/report.c
> @@ -105,15 +105,20 @@ static void end_report(unsigned long *flags)
>         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) {
> -               unsigned long *entries;
> -               unsigned int nr_entries;
> -
> -               nr_entries = stack_depot_fetch(track->stack, &entries);
> -               stack_trace_print(entries, nr_entries, 0);
> +               print_stack(track->stack);
>         } else {
>                 pr_err("(stack is not available)\n");
>         }
> @@ -192,6 +197,19 @@ static void describe_object(struct kmem_cache *cache, void *object,
>                 free_track = kasan_get_free_track(cache, object, tag);
>                 print_track(free_track, "Freed");
>                 pr_err("\n");
> +
> +#ifdef CONFIG_KASAN_GENERIC
> +               if (alloc_info->aux_stack[0]) {
> +                       pr_err("Last call_rcu():\n");
> +                       print_stack(alloc_info->aux_stack[0]);
> +                       pr_err("\n");
> +               }
> +               if (alloc_info->aux_stack[1]) {
> +                       pr_err("Second to last call_rcu():\n");
> +                       print_stack(alloc_info->aux_stack[1]);
> +                       pr_err("\n");
> +               }
> +#endif
>         }
>
>         describe_object_addr(cache, object, addr);
> --
> 2.18.0
>
> --
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> To unsubscribe from this group and stop receiving emails from it, send an email to kasan-dev+unsubscribe@googlegroups.com.
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Walter Wu May 26, 2020, 1:34 a.m. UTC | #2
On Mon, 2020-05-25 at 11:56 +0200, Dmitry Vyukov wrote:
> On Fri, May 22, 2020 at 4:01 AM Walter Wu <walter-zh.wu@mediatek.com> wrote:
> >
> > This feature will record the last two call_rcu() call stacks and
> > prints up to 2 call_rcu() call stacks in KASAN report.
> >
> > When call_rcu() is called, we store the call_rcu() call stack into
> > slub alloc meta-data, so that the KASAN report can print rcu stack.
> >
> > [1]https://bugzilla.kernel.org/show_bug.cgi?id=198437
> > [2]https://groups.google.com/forum/#!searchin/kasan-dev/better$20stack$20traces$20for$20rcu%7Csort:date/kasan-dev/KQsjT_88hDE/7rNUZprRBgAJ
> 
> Hi Walter,
> 
> The series look good to me. Thanks for bearing with me. I am eager to
> see this in syzbot reports.
> 
> Reviewed-and-tested-by: Dmitry Vyukov <dvyukov@google.com>
> 

Hi Dmitry,

I appreciate for your response. This patches make KASAN report more
better and let me learn a lot. Thank you for good suggestion and
detailed explanation.

Walter

> > Signed-off-by: Walter Wu <walter-zh.wu@mediatek.com>
> > Suggested-by: Dmitry Vyukov <dvyukov@google.com>
> > Acked-by: Paul E. McKenney <paulmck@kernel.org>
> > Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
> > Cc: Dmitry Vyukov <dvyukov@google.com>
> > Cc: Alexander Potapenko <glider@google.com>
> > Cc: Andrew Morton <akpm@linux-foundation.org>
> > Cc: Josh Triplett <josh@joshtriplett.org>
> > Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
> > Cc: Lai Jiangshan <jiangshanlai@gmail.com>
> > Cc: Joel Fernandes <joel@joelfernandes.org>
> > Cc: Andrey Konovalov <andreyknvl@google.com>
> > ---
> >  include/linux/kasan.h |  2 ++
> >  kernel/rcu/tree.c     |  2 ++
> >  mm/kasan/common.c     |  4 ++--
> >  mm/kasan/generic.c    | 21 +++++++++++++++++++++
> >  mm/kasan/kasan.h      | 10 ++++++++++
> >  mm/kasan/report.c     | 28 +++++++++++++++++++++++-----
> >  6 files changed, 60 insertions(+), 7 deletions(-)
> >
> > diff --git a/include/linux/kasan.h b/include/linux/kasan.h
> > index 31314ca7c635..23b7ee00572d 100644
> > --- a/include/linux/kasan.h
> > +++ b/include/linux/kasan.h
> > @@ -174,11 +174,13 @@ static inline size_t kasan_metadata_size(struct kmem_cache *cache) { return 0; }
> >
> >  void kasan_cache_shrink(struct kmem_cache *cache);
> >  void kasan_cache_shutdown(struct kmem_cache *cache);
> > +void kasan_record_aux_stack(void *ptr);
> >
> >  #else /* CONFIG_KASAN_GENERIC */
> >
> >  static inline void kasan_cache_shrink(struct kmem_cache *cache) {}
> >  static inline void kasan_cache_shutdown(struct kmem_cache *cache) {}
> > +static inline void kasan_record_aux_stack(void *ptr) {}
> >
> >  #endif /* CONFIG_KASAN_GENERIC */
> >
> > diff --git a/kernel/rcu/tree.c b/kernel/rcu/tree.c
> > index 06548e2ebb72..36a4ff7f320b 100644
> > --- a/kernel/rcu/tree.c
> > +++ b/kernel/rcu/tree.c
> > @@ -57,6 +57,7 @@
> >  #include <linux/slab.h>
> >  #include <linux/sched/isolation.h>
> >  #include <linux/sched/clock.h>
> > +#include <linux/kasan.h>
> >  #include "../time/tick-internal.h"
> >
> >  #include "tree.h"
> > @@ -2668,6 +2669,7 @@ __call_rcu(struct rcu_head *head, rcu_callback_t func)
> >         head->func = func;
> >         head->next = NULL;
> >         local_irq_save(flags);
> > +       kasan_record_aux_stack(head);
> >         rdp = this_cpu_ptr(&rcu_data);
> >
> >         /* Add the callback to our list. */
> > diff --git a/mm/kasan/common.c b/mm/kasan/common.c
> > index 2906358e42f0..8bc618289bb1 100644
> > --- a/mm/kasan/common.c
> > +++ b/mm/kasan/common.c
> > @@ -41,7 +41,7 @@
> >  #include "kasan.h"
> >  #include "../slab.h"
> >
> > -static inline depot_stack_handle_t save_stack(gfp_t flags)
> > +depot_stack_handle_t kasan_save_stack(gfp_t flags)
> >  {
> >         unsigned long entries[KASAN_STACK_DEPTH];
> >         unsigned int nr_entries;
> > @@ -54,7 +54,7 @@ static inline depot_stack_handle_t save_stack(gfp_t flags)
> >  static inline void set_track(struct kasan_track *track, gfp_t flags)
> >  {
> >         track->pid = current->pid;
> > -       track->stack = save_stack(flags);
> > +       track->stack = kasan_save_stack(flags);
> >  }
> >
> >  void kasan_enable_current(void)
> > diff --git a/mm/kasan/generic.c b/mm/kasan/generic.c
> > index 56ff8885fe2e..8acf48882ba2 100644
> > --- a/mm/kasan/generic.c
> > +++ b/mm/kasan/generic.c
> > @@ -325,3 +325,24 @@ DEFINE_ASAN_SET_SHADOW(f2);
> >  DEFINE_ASAN_SET_SHADOW(f3);
> >  DEFINE_ASAN_SET_SHADOW(f5);
> >  DEFINE_ASAN_SET_SHADOW(f8);
> > +
> > +void kasan_record_aux_stack(void *addr)
> > +{
> > +       struct page *page = kasan_addr_to_page(addr);
> > +       struct kmem_cache *cache;
> > +       struct kasan_alloc_meta *alloc_info;
> > +       void *object;
> > +
> > +       if (!(page && PageSlab(page)))
> > +               return;
> > +
> > +       cache = page->slab_cache;
> > +       object = nearest_obj(cache, page, addr);
> > +       alloc_info = get_alloc_info(cache, object);
> > +
> > +       /*
> > +        * record the last two call_rcu() call stacks.
> > +        */
> > +       alloc_info->aux_stack[1] = alloc_info->aux_stack[0];
> > +       alloc_info->aux_stack[0] = kasan_save_stack(GFP_NOWAIT);
> > +}
> > diff --git a/mm/kasan/kasan.h b/mm/kasan/kasan.h
> > index e8f37199d885..a7391bc83070 100644
> > --- a/mm/kasan/kasan.h
> > +++ b/mm/kasan/kasan.h
> > @@ -104,7 +104,15 @@ struct kasan_track {
> >
> >  struct kasan_alloc_meta {
> >         struct kasan_track alloc_track;
> > +#ifdef CONFIG_KASAN_GENERIC
> > +       /*
> > +        * call_rcu() call stack is stored into struct kasan_alloc_meta.
> > +        * The free stack is stored into struct kasan_free_meta.
> > +        */
> > +       depot_stack_handle_t aux_stack[2];
> > +#else
> >         struct kasan_track free_track[KASAN_NR_FREE_STACKS];
> > +#endif
> >  #ifdef CONFIG_KASAN_SW_TAGS_IDENTIFY
> >         u8 free_pointer_tag[KASAN_NR_FREE_STACKS];
> >         u8 free_track_idx;
> > @@ -159,6 +167,8 @@ void kasan_report_invalid_free(void *object, unsigned long ip);
> >
> >  struct page *kasan_addr_to_page(const void *addr);
> >
> > +depot_stack_handle_t kasan_save_stack(gfp_t flags);
> > +
> >  #if defined(CONFIG_KASAN_GENERIC) && \
> >         (defined(CONFIG_SLAB) || defined(CONFIG_SLUB))
> >  void quarantine_put(struct kasan_free_meta *info, struct kmem_cache *cache);
> > diff --git a/mm/kasan/report.c b/mm/kasan/report.c
> > index 80f23c9da6b0..2421a4bd9227 100644
> > --- a/mm/kasan/report.c
> > +++ b/mm/kasan/report.c
> > @@ -105,15 +105,20 @@ static void end_report(unsigned long *flags)
> >         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) {
> > -               unsigned long *entries;
> > -               unsigned int nr_entries;
> > -
> > -               nr_entries = stack_depot_fetch(track->stack, &entries);
> > -               stack_trace_print(entries, nr_entries, 0);
> > +               print_stack(track->stack);
> >         } else {
> >                 pr_err("(stack is not available)\n");
> >         }
> > @@ -192,6 +197,19 @@ static void describe_object(struct kmem_cache *cache, void *object,
> >                 free_track = kasan_get_free_track(cache, object, tag);
> >                 print_track(free_track, "Freed");
> >                 pr_err("\n");
> > +
> > +#ifdef CONFIG_KASAN_GENERIC
> > +               if (alloc_info->aux_stack[0]) {
> > +                       pr_err("Last call_rcu():\n");
> > +                       print_stack(alloc_info->aux_stack[0]);
> > +                       pr_err("\n");
> > +               }
> > +               if (alloc_info->aux_stack[1]) {
> > +                       pr_err("Second to last call_rcu():\n");
> > +                       print_stack(alloc_info->aux_stack[1]);
> > +                       pr_err("\n");
> > +               }
> > +#endif
> >         }
> >
> >         describe_object_addr(cache, object, addr);
> > --
> > 2.18.0
> >
> > --
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> > To unsubscribe from this group and stop receiving emails from it, send an email to kasan-dev+unsubscribe@googlegroups.com.
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Patch
diff mbox series

diff --git a/include/linux/kasan.h b/include/linux/kasan.h
index 31314ca7c635..23b7ee00572d 100644
--- a/include/linux/kasan.h
+++ b/include/linux/kasan.h
@@ -174,11 +174,13 @@  static inline size_t kasan_metadata_size(struct kmem_cache *cache) { return 0; }
 
 void kasan_cache_shrink(struct kmem_cache *cache);
 void kasan_cache_shutdown(struct kmem_cache *cache);
+void kasan_record_aux_stack(void *ptr);
 
 #else /* CONFIG_KASAN_GENERIC */
 
 static inline void kasan_cache_shrink(struct kmem_cache *cache) {}
 static inline void kasan_cache_shutdown(struct kmem_cache *cache) {}
+static inline void kasan_record_aux_stack(void *ptr) {}
 
 #endif /* CONFIG_KASAN_GENERIC */
 
diff --git a/kernel/rcu/tree.c b/kernel/rcu/tree.c
index 06548e2ebb72..36a4ff7f320b 100644
--- a/kernel/rcu/tree.c
+++ b/kernel/rcu/tree.c
@@ -57,6 +57,7 @@ 
 #include <linux/slab.h>
 #include <linux/sched/isolation.h>
 #include <linux/sched/clock.h>
+#include <linux/kasan.h>
 #include "../time/tick-internal.h"
 
 #include "tree.h"
@@ -2668,6 +2669,7 @@  __call_rcu(struct rcu_head *head, rcu_callback_t func)
 	head->func = func;
 	head->next = NULL;
 	local_irq_save(flags);
+	kasan_record_aux_stack(head);
 	rdp = this_cpu_ptr(&rcu_data);
 
 	/* Add the callback to our list. */
diff --git a/mm/kasan/common.c b/mm/kasan/common.c
index 2906358e42f0..8bc618289bb1 100644
--- a/mm/kasan/common.c
+++ b/mm/kasan/common.c
@@ -41,7 +41,7 @@ 
 #include "kasan.h"
 #include "../slab.h"
 
-static inline depot_stack_handle_t save_stack(gfp_t flags)
+depot_stack_handle_t kasan_save_stack(gfp_t flags)
 {
 	unsigned long entries[KASAN_STACK_DEPTH];
 	unsigned int nr_entries;
@@ -54,7 +54,7 @@  static inline depot_stack_handle_t save_stack(gfp_t flags)
 static inline void set_track(struct kasan_track *track, gfp_t flags)
 {
 	track->pid = current->pid;
-	track->stack = save_stack(flags);
+	track->stack = kasan_save_stack(flags);
 }
 
 void kasan_enable_current(void)
diff --git a/mm/kasan/generic.c b/mm/kasan/generic.c
index 56ff8885fe2e..8acf48882ba2 100644
--- a/mm/kasan/generic.c
+++ b/mm/kasan/generic.c
@@ -325,3 +325,24 @@  DEFINE_ASAN_SET_SHADOW(f2);
 DEFINE_ASAN_SET_SHADOW(f3);
 DEFINE_ASAN_SET_SHADOW(f5);
 DEFINE_ASAN_SET_SHADOW(f8);
+
+void kasan_record_aux_stack(void *addr)
+{
+	struct page *page = kasan_addr_to_page(addr);
+	struct kmem_cache *cache;
+	struct kasan_alloc_meta *alloc_info;
+	void *object;
+
+	if (!(page && PageSlab(page)))
+		return;
+
+	cache = page->slab_cache;
+	object = nearest_obj(cache, page, addr);
+	alloc_info = get_alloc_info(cache, object);
+
+	/*
+	 * record the last two call_rcu() call stacks.
+	 */
+	alloc_info->aux_stack[1] = alloc_info->aux_stack[0];
+	alloc_info->aux_stack[0] = kasan_save_stack(GFP_NOWAIT);
+}
diff --git a/mm/kasan/kasan.h b/mm/kasan/kasan.h
index e8f37199d885..a7391bc83070 100644
--- a/mm/kasan/kasan.h
+++ b/mm/kasan/kasan.h
@@ -104,7 +104,15 @@  struct kasan_track {
 
 struct kasan_alloc_meta {
 	struct kasan_track alloc_track;
+#ifdef CONFIG_KASAN_GENERIC
+	/*
+	 * call_rcu() call stack is stored into struct kasan_alloc_meta.
+	 * The free stack is stored into struct kasan_free_meta.
+	 */
+	depot_stack_handle_t aux_stack[2];
+#else
 	struct kasan_track free_track[KASAN_NR_FREE_STACKS];
+#endif
 #ifdef CONFIG_KASAN_SW_TAGS_IDENTIFY
 	u8 free_pointer_tag[KASAN_NR_FREE_STACKS];
 	u8 free_track_idx;
@@ -159,6 +167,8 @@  void kasan_report_invalid_free(void *object, unsigned long ip);
 
 struct page *kasan_addr_to_page(const void *addr);
 
+depot_stack_handle_t kasan_save_stack(gfp_t flags);
+
 #if defined(CONFIG_KASAN_GENERIC) && \
 	(defined(CONFIG_SLAB) || defined(CONFIG_SLUB))
 void quarantine_put(struct kasan_free_meta *info, struct kmem_cache *cache);
diff --git a/mm/kasan/report.c b/mm/kasan/report.c
index 80f23c9da6b0..2421a4bd9227 100644
--- a/mm/kasan/report.c
+++ b/mm/kasan/report.c
@@ -105,15 +105,20 @@  static void end_report(unsigned long *flags)
 	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) {
-		unsigned long *entries;
-		unsigned int nr_entries;
-
-		nr_entries = stack_depot_fetch(track->stack, &entries);
-		stack_trace_print(entries, nr_entries, 0);
+		print_stack(track->stack);
 	} else {
 		pr_err("(stack is not available)\n");
 	}
@@ -192,6 +197,19 @@  static void describe_object(struct kmem_cache *cache, void *object,
 		free_track = kasan_get_free_track(cache, object, tag);
 		print_track(free_track, "Freed");
 		pr_err("\n");
+
+#ifdef CONFIG_KASAN_GENERIC
+		if (alloc_info->aux_stack[0]) {
+			pr_err("Last call_rcu():\n");
+			print_stack(alloc_info->aux_stack[0]);
+			pr_err("\n");
+		}
+		if (alloc_info->aux_stack[1]) {
+			pr_err("Second to last call_rcu():\n");
+			print_stack(alloc_info->aux_stack[1]);
+			pr_err("\n");
+		}
+#endif
 	}
 
 	describe_object_addr(cache, object, addr);