This is a note to let you know that I've just added the patch titled
IB/uverbs: Improve lockdep_check
to the 4.15-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git%3Ba=su...
The filename of the patch is: ib-uverbs-improve-lockdep_check.patch and it can be found in the queue-4.15 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree, please let stable@vger.kernel.org know about it.
From 104f268d439b3c21c83708e52946a4d8d37f3d0f Mon Sep 17 00:00:00 2001
From: Jason Gunthorpe jgg@mellanox.com Date: Tue, 13 Feb 2018 12:18:38 +0200 Subject: IB/uverbs: Improve lockdep_check
From: Jason Gunthorpe jgg@mellanox.com
commit 104f268d439b3c21c83708e52946a4d8d37f3d0f upstream.
This is really being used as an assert that the expected usecnt is being held and implicitly that the usecnt is valid. Rename it to assert_uverbs_usecnt and tighten the checks to only accept valid values of usecnt (eg 0 and < -1 are invalid).
The tigher checkes make the assertion cover more cases and is more likely to find bugs via syzkaller/etc.
Fixes: 3832125624b7 ("IB/core: Add support for idr types") Signed-off-by: Leon Romanovsky leon@kernel.org Signed-off-by: Jason Gunthorpe jgg@mellanox.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- drivers/infiniband/core/rdma_core.c | 12 ++++++------ 1 file changed, 6 insertions(+), 6 deletions(-)
--- a/drivers/infiniband/core/rdma_core.c +++ b/drivers/infiniband/core/rdma_core.c @@ -407,13 +407,13 @@ static int __must_check remove_commit_fd return ret; }
-static void lockdep_check(struct ib_uobject *uobj, bool exclusive) +static void assert_uverbs_usecnt(struct ib_uobject *uobj, bool exclusive) { #ifdef CONFIG_LOCKDEP if (exclusive) - WARN_ON(atomic_read(&uobj->usecnt) > 0); + WARN_ON(atomic_read(&uobj->usecnt) != -1); else - WARN_ON(atomic_read(&uobj->usecnt) == -1); + WARN_ON(atomic_read(&uobj->usecnt) <= 0); #endif }
@@ -452,7 +452,7 @@ int __must_check rdma_remove_commit_uobj WARN(true, "ib_uverbs: Cleanup is running while removing an uobject\n"); return 0; } - lockdep_check(uobj, true); + assert_uverbs_usecnt(uobj, true); ret = _rdma_remove_commit_uobject(uobj, RDMA_REMOVE_DESTROY);
up_read(&ucontext->cleanup_rwsem); @@ -482,7 +482,7 @@ int rdma_explicit_destroy(struct ib_uobj WARN(true, "ib_uverbs: Cleanup is running while removing an uobject\n"); return 0; } - lockdep_check(uobject, true); + assert_uverbs_usecnt(uobject, true); ret = uobject->type->type_class->remove_commit(uobject, RDMA_REMOVE_DESTROY); if (ret) @@ -569,7 +569,7 @@ static void lookup_put_fd_uobject(struct
void rdma_lookup_put_uobject(struct ib_uobject *uobj, bool exclusive) { - lockdep_check(uobj, exclusive); + assert_uverbs_usecnt(uobj, exclusive); uobj->type->type_class->lookup_put(uobj, exclusive); /* * In order to unlock an object, either decrease its usecnt for
Patches currently in stable-queue which might be from jgg@mellanox.com are
queue-4.15/ib-uverbs-improve-lockdep_check.patch