diff options
author | Ohad Ben-Cohen <ohad@wizery.com> | 2012-06-06 03:09:25 -0400 |
---|---|---|
committer | Ohad Ben-Cohen <ohad@wizery.com> | 2012-07-04 04:51:42 -0400 |
commit | 5a081caa0414b9bbb82c17ffab9d6fe66edbb72f (patch) | |
tree | de3c3d2044db5843e836690732a4f688985e35af /include | |
parent | 6887a4131da3adaab011613776d865f4bcfb5678 (diff) |
rpmsg: avoid premature deallocation of endpoints
When an inbound message arrives, the rpmsg core looks up its
associated endpoint and invokes the registered callback.
If a message arrives while its endpoint is being removed (because
the rpmsg driver was removed, or a recovery of a remote processor
has kicked in) we must ensure atomicity, i.e.:
- Either the ept is removed before it is found
or
- The ept is found but will not be freed until the callback returns
This is achieved by maintaining a per-ept reference count, which,
when drops to zero, will trigger deallocation of the ept.
With this in hand, it is now forbidden to directly deallocate
epts once they have been added to the endpoints idr.
Cc: stable <stable@vger.kernel.org>
Reported-by: Fernando Guzman Lugo <fernando.lugo@ti.com>
Signed-off-by: Ohad Ben-Cohen <ohad@wizery.com>
Diffstat (limited to 'include')
-rw-r--r-- | include/linux/rpmsg.h | 3 |
1 files changed, 3 insertions, 0 deletions
diff --git a/include/linux/rpmsg.h b/include/linux/rpmsg.h index a8e50e44203c..195f373590b8 100644 --- a/include/linux/rpmsg.h +++ b/include/linux/rpmsg.h | |||
@@ -38,6 +38,7 @@ | |||
38 | #include <linux/types.h> | 38 | #include <linux/types.h> |
39 | #include <linux/device.h> | 39 | #include <linux/device.h> |
40 | #include <linux/mod_devicetable.h> | 40 | #include <linux/mod_devicetable.h> |
41 | #include <linux/kref.h> | ||
41 | 42 | ||
42 | /* The feature bitmap for virtio rpmsg */ | 43 | /* The feature bitmap for virtio rpmsg */ |
43 | #define VIRTIO_RPMSG_F_NS 0 /* RP supports name service notifications */ | 44 | #define VIRTIO_RPMSG_F_NS 0 /* RP supports name service notifications */ |
@@ -120,6 +121,7 @@ typedef void (*rpmsg_rx_cb_t)(struct rpmsg_channel *, void *, int, void *, u32); | |||
120 | /** | 121 | /** |
121 | * struct rpmsg_endpoint - binds a local rpmsg address to its user | 122 | * struct rpmsg_endpoint - binds a local rpmsg address to its user |
122 | * @rpdev: rpmsg channel device | 123 | * @rpdev: rpmsg channel device |
124 | * @refcount: when this drops to zero, the ept is deallocated | ||
123 | * @cb: rx callback handler | 125 | * @cb: rx callback handler |
124 | * @addr: local rpmsg address | 126 | * @addr: local rpmsg address |
125 | * @priv: private data for the driver's use | 127 | * @priv: private data for the driver's use |
@@ -140,6 +142,7 @@ typedef void (*rpmsg_rx_cb_t)(struct rpmsg_channel *, void *, int, void *, u32); | |||
140 | */ | 142 | */ |
141 | struct rpmsg_endpoint { | 143 | struct rpmsg_endpoint { |
142 | struct rpmsg_channel *rpdev; | 144 | struct rpmsg_channel *rpdev; |
145 | struct kref refcount; | ||
143 | rpmsg_rx_cb_t cb; | 146 | rpmsg_rx_cb_t cb; |
144 | u32 addr; | 147 | u32 addr; |
145 | void *priv; | 148 | void *priv; |