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;a=summary
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@xxxxxxxxxxxxxxx> know about it.
>From 104f268d439b3c21c83708e52946a4d8d37f3d0f Mon Sep 17 00:00:00 2001
From: Jason Gunthorpe <jgg@xxxxxxxxxxxx>
Date: Tue, 13 Feb 2018 12:18:38 +0200
Subject: IB/uverbs: Improve lockdep_check
From: Jason Gunthorpe <jgg@xxxxxxxxxxxx>
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@xxxxxxxxxx>
Signed-off-by: Jason Gunthorpe <jgg@xxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
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@xxxxxxxxxxxx are
queue-4.15/ib-uverbs-improve-lockdep_check.patch