Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67;
From:   Daniel Vetter <daniel.vetter@ffwll.ch>
To:     LKML <linux-kernel@vger.kernel.org>
Cc:     DRI Development <dri-devel@lists.freedesktop.org>,
        Daniel Vetter <daniel.vetter@ffwll.ch>,
        syzbot+aaedc50d99a03250fe1f@syzkaller.appspotmail.com,
        Jason Gunthorpe <jgg@mellanox.com>,
        Daniel Vetter <daniel.vetter@intel.com>,
        Andrew Morton <akpm@linux-foundation.org>,
        =?UTF-8?q?J=C3=A9r=C3=B4me=20Glisse?= <jglisse@redhat.com>,
        Ralph Campbell <rcampbell@nvidia.com>,
        Jason Gunthorpe <jgg@ziepe.ca>,
        Ira Weiny <ira.weiny@intel.com>,
        Michal Hocko <mhocko@suse.com>,
        Sean Christopherson <sean.j.christopherson@intel.com>,
        Jean-Philippe Brucker <jean-philippe@linaro.org>,
        linux-mm@kvack.org
Subject: [PATCH] mm, notifier: Fix early return case for new lockdep annotations
Date:   Fri,  6 Sep 2019 19:47:30 +0200
Message-Id: <20190906174730.22462-1-daniel.vetter@ffwll.ch>
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk

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
-- 
2.23.0