mm, notifier: Fix early return case for new lockdep annotations
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Message ID 20190906174730.22462-1-daniel.vetter@ffwll.ch
State New
Headers show
Series
  • mm, notifier: Fix early return case for new lockdep annotations
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Commit Message

Daniel Vetter Sept. 6, 2019, 5:47 p.m. UTC
I missed that when extending the lockdep annotations to the
nonblocking case.

I missed this while testing since in the i915 mmu notifiers is hitting
a nice lockdep splat already before the point of going into oom killer
mode :-/

Reported-by: syzbot+aaedc50d99a03250fe1f@syzkaller.appspotmail.com
Fixes: d2b219ed03d4 ("mm/mmu_notifiers: add a lockdep map for invalidate_range_start/end")
Cc: Jason Gunthorpe <jgg@mellanox.com>
Cc: Daniel Vetter <daniel.vetter@intel.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: "Jérôme Glisse" <jglisse@redhat.com>
Cc: Ralph Campbell <rcampbell@nvidia.com>
Cc: Jason Gunthorpe <jgg@ziepe.ca>
Cc: Ira Weiny <ira.weiny@intel.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: Sean Christopherson <sean.j.christopherson@intel.com>
Cc: Jean-Philippe Brucker <jean-philippe@linaro.org>
Cc: linux-mm@kvack.org
Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
---
 include/linux/mmu_notifier.h | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

Comments

John Hubbard Sept. 6, 2019, 10:31 p.m. UTC | #1
On 9/6/19 10:47 AM, Daniel Vetter wrote:
> I missed that when extending the lockdep annotations to the
> nonblocking case.
> 
> I missed this while testing since in the i915 mmu notifiers is hitting
> a nice lockdep splat already before the point of going into oom killer
> mode :-/
> 
> Reported-by: syzbot+aaedc50d99a03250fe1f@syzkaller.appspotmail.com
> Fixes: d2b219ed03d4 ("mm/mmu_notifiers: add a lockdep map for invalidate_range_start/end")
> Cc: Jason Gunthorpe <jgg@mellanox.com>
> Cc: Daniel Vetter <daniel.vetter@intel.com>
> Cc: Andrew Morton <akpm@linux-foundation.org>
> Cc: "Jérôme Glisse" <jglisse@redhat.com>
> Cc: Ralph Campbell <rcampbell@nvidia.com>
> Cc: Jason Gunthorpe <jgg@ziepe.ca>
> Cc: Ira Weiny <ira.weiny@intel.com>
> Cc: Michal Hocko <mhocko@suse.com>
> Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
> Cc: Sean Christopherson <sean.j.christopherson@intel.com>
> Cc: Jean-Philippe Brucker <jean-philippe@linaro.org>
> Cc: linux-mm@kvack.org
> Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
> ---
>  include/linux/mmu_notifier.h | 5 +++--
>  1 file changed, 3 insertions(+), 2 deletions(-)
> 
> diff --git a/include/linux/mmu_notifier.h b/include/linux/mmu_notifier.h
> index 5a03417e5bf7..4edd98b06834 100644
> --- a/include/linux/mmu_notifier.h
> +++ b/include/linux/mmu_notifier.h
> @@ -356,13 +356,14 @@ mmu_notifier_invalidate_range_start(struct mmu_notifier_range *range)
>  static inline int
>  mmu_notifier_invalidate_range_start_nonblock(struct mmu_notifier_range *range)
>  {
> +	int ret = 0;
>  	lock_map_acquire(&__mmu_notifier_invalidate_range_start_map);
>  	if (mm_has_notifiers(range->mm)) {
>  		range->flags &= ~MMU_NOTIFIER_RANGE_BLOCKABLE;
> -		return __mmu_notifier_invalidate_range_start(range);
> +		ret = __mmu_notifier_invalidate_range_start(range);
>  	}
>  	lock_map_release(&__mmu_notifier_invalidate_range_start_map);
> -	return 0;
> +	return ret;
>  }
>  
>  static inline void
> 

Reviewed-by: John Hubbard <jhubbard@nvidia.com>


thanks,
Jason Gunthorpe Sept. 7, 2019, 7:33 a.m. UTC | #2
On Fri, Sep 06, 2019 at 07:47:30PM +0200, Daniel Vetter wrote:

> diff --git a/include/linux/mmu_notifier.h b/include/linux/mmu_notifier.h
> index 5a03417e5bf7..4edd98b06834 100644
> +++ b/include/linux/mmu_notifier.h
> @@ -356,13 +356,14 @@ mmu_notifier_invalidate_range_start(struct mmu_notifier_range *range)
>  static inline int
>  mmu_notifier_invalidate_range_start_nonblock(struct mmu_notifier_range *range)
>  {
> +	int ret = 0;
>  	lock_map_acquire(&__mmu_notifier_invalidate_range_start_map);
>  	if (mm_has_notifiers(range->mm)) {
>  		range->flags &= ~MMU_NOTIFIER_RANGE_BLOCKABLE;
> -		return __mmu_notifier_invalidate_range_start(range);
> +		ret = __mmu_notifier_invalidate_range_start(range);
>  	}
>  	lock_map_release(&__mmu_notifier_invalidate_range_start_map);
> -	return 0;
> +	return ret;

Gar, yes. Since nobody has grabbed hmm.git I've squashed this into the
original patch and fixed the checkpatch warning about missing line
after the ret

Everything should be in linux-next the next time it builds

Thanks,
Jason
David Hildenbrand Sept. 9, 2019, 8:22 a.m. UTC | #3
On 06.09.19 19:47, Daniel Vetter wrote:
> I missed that when extending the lockdep annotations to the
> nonblocking case.
> 
> I missed this while testing since in the i915 mmu notifiers is hitting
> a nice lockdep splat already before the point of going into oom killer
> mode :-/
> 
> Reported-by: syzbot+aaedc50d99a03250fe1f@syzkaller.appspotmail.com
> Fixes: d2b219ed03d4 ("mm/mmu_notifiers: add a lockdep map for invalidate_range_start/end")
> Cc: Jason Gunthorpe <jgg@mellanox.com>
> Cc: Daniel Vetter <daniel.vetter@intel.com>
> Cc: Andrew Morton <akpm@linux-foundation.org>
> Cc: "Jérôme Glisse" <jglisse@redhat.com>
> Cc: Ralph Campbell <rcampbell@nvidia.com>
> Cc: Jason Gunthorpe <jgg@ziepe.ca>
> Cc: Ira Weiny <ira.weiny@intel.com>
> Cc: Michal Hocko <mhocko@suse.com>
> Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
> Cc: Sean Christopherson <sean.j.christopherson@intel.com>
> Cc: Jean-Philippe Brucker <jean-philippe@linaro.org>
> Cc: linux-mm@kvack.org
> Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
> ---
>  include/linux/mmu_notifier.h | 5 +++--
>  1 file changed, 3 insertions(+), 2 deletions(-)
> 
> diff --git a/include/linux/mmu_notifier.h b/include/linux/mmu_notifier.h
> index 5a03417e5bf7..4edd98b06834 100644
> --- a/include/linux/mmu_notifier.h
> +++ b/include/linux/mmu_notifier.h
> @@ -356,13 +356,14 @@ mmu_notifier_invalidate_range_start(struct mmu_notifier_range *range)
>  static inline int
>  mmu_notifier_invalidate_range_start_nonblock(struct mmu_notifier_range *range)
>  {
> +	int ret = 0;
>  	lock_map_acquire(&__mmu_notifier_invalidate_range_start_map);
>  	if (mm_has_notifiers(range->mm)) {
>  		range->flags &= ~MMU_NOTIFIER_RANGE_BLOCKABLE;
> -		return __mmu_notifier_invalidate_range_start(range);
> +		ret = __mmu_notifier_invalidate_range_start(range);
>  	}
>  	lock_map_release(&__mmu_notifier_invalidate_range_start_map);
> -	return 0;
> +	return ret;
>  }
>  
>  static inline void
> 

Reviewed-by: David Hildenbrand <david@redhat.com>

Patch
diff mbox series

diff --git a/include/linux/mmu_notifier.h b/include/linux/mmu_notifier.h
index 5a03417e5bf7..4edd98b06834 100644
--- a/include/linux/mmu_notifier.h
+++ b/include/linux/mmu_notifier.h
@@ -356,13 +356,14 @@  mmu_notifier_invalidate_range_start(struct mmu_notifier_range *range)
 static inline int
 mmu_notifier_invalidate_range_start_nonblock(struct mmu_notifier_range *range)
 {
+	int ret = 0;
 	lock_map_acquire(&__mmu_notifier_invalidate_range_start_map);
 	if (mm_has_notifiers(range->mm)) {
 		range->flags &= ~MMU_NOTIFIER_RANGE_BLOCKABLE;
-		return __mmu_notifier_invalidate_range_start(range);
+		ret = __mmu_notifier_invalidate_range_start(range);
 	}
 	lock_map_release(&__mmu_notifier_invalidate_range_start_map);
-	return 0;
+	return ret;
 }
 
 static inline void