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author | Mauro Carvalho Chehab <mchehab@redhat.com> | 2012-07-30 00:09:39 (GMT) |
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committer | Mauro Carvalho Chehab <mchehab@redhat.com> | 2012-07-30 00:09:39 (GMT) |
commit | 73bcc49959e4e40911dd0dd634bf1b353827df66 (patch) | |
tree | 6b0c1d440c490a65c51ab5cf5aee7095cb4089d3 /drivers/rpmsg | |
parent | 8447c4d15e357a458c9051ddc84aa6c8b9c27000 (diff) | |
parent | 28a33cbc24e4256c143dce96c7d93bf423229f92 (diff) | |
download | linux-fsl-qoriq-73bcc49959e4e40911dd0dd634bf1b353827df66.tar.xz |
Merge tag 'v3.5'
Linux 3.5
* tag 'v3.5': (1242 commits)
Linux 3.5
Remove SYSTEM_SUSPEND_DISK system state
kdb: Switch to nolock variants of kmsg_dump functions
printk: Implement some unlocked kmsg_dump functions
printk: Remove kdb_syslog_data
kdb: Revive dmesg command
dm raid1: set discard_zeroes_data_unsupported
dm thin: do not send discards to shared blocks
dm raid1: fix crash with mirror recovery and discard
pnfs-obj: Fix __r4w_get_page when offset is beyond i_size
pnfs-obj: don't leak objio_state if ore_write/read fails
ore: Unlock r4w pages in exact reverse order of locking
ore: Remove support of partial IO request (NFS crash)
ore: Fix NFS crash by supporting any unaligned RAID IO
UBIFS: fix a bug in empty space fix-up
cx25821: Remove bad strcpy to read-only char*
HID: hid-multitouch: add support for Zytronic panels
MIPS: PCI: Move fixups from __init to __devinit.
MIPS: Fix bug.h MIPS build regression
MIPS: sync-r4k: remove redundant irq operation
...
Diffstat (limited to 'drivers/rpmsg')
-rw-r--r-- | drivers/rpmsg/virtio_rpmsg_bus.c | 57 |
1 files changed, 51 insertions, 6 deletions
diff --git a/drivers/rpmsg/virtio_rpmsg_bus.c b/drivers/rpmsg/virtio_rpmsg_bus.c index 75506ec..f56c8ba 100644 --- a/drivers/rpmsg/virtio_rpmsg_bus.c +++ b/drivers/rpmsg/virtio_rpmsg_bus.c @@ -188,6 +188,26 @@ static int rpmsg_uevent(struct device *dev, struct kobj_uevent_env *env) rpdev->id.name); } +/** + * __ept_release() - deallocate an rpmsg endpoint + * @kref: the ept's reference count + * + * This function deallocates an ept, and is invoked when its @kref refcount + * drops to zero. + * + * Never invoke this function directly! + */ +static void __ept_release(struct kref *kref) +{ + struct rpmsg_endpoint *ept = container_of(kref, struct rpmsg_endpoint, + refcount); + /* + * At this point no one holds a reference to ept anymore, + * so we can directly free it + */ + kfree(ept); +} + /* for more info, see below documentation of rpmsg_create_ept() */ static struct rpmsg_endpoint *__rpmsg_create_ept(struct virtproc_info *vrp, struct rpmsg_channel *rpdev, rpmsg_rx_cb_t cb, @@ -206,6 +226,9 @@ static struct rpmsg_endpoint *__rpmsg_create_ept(struct virtproc_info *vrp, return NULL; } + kref_init(&ept->refcount); + mutex_init(&ept->cb_lock); + ept->rpdev = rpdev; ept->cb = cb; ept->priv = priv; @@ -238,7 +261,7 @@ rem_idr: idr_remove(&vrp->endpoints, request); free_ept: mutex_unlock(&vrp->endpoints_lock); - kfree(ept); + kref_put(&ept->refcount, __ept_release); return NULL; } @@ -302,11 +325,17 @@ EXPORT_SYMBOL(rpmsg_create_ept); static void __rpmsg_destroy_ept(struct virtproc_info *vrp, struct rpmsg_endpoint *ept) { + /* make sure new inbound messages can't find this ept anymore */ mutex_lock(&vrp->endpoints_lock); idr_remove(&vrp->endpoints, ept->addr); mutex_unlock(&vrp->endpoints_lock); - kfree(ept); + /* make sure in-flight inbound messages won't invoke cb anymore */ + mutex_lock(&ept->cb_lock); + ept->cb = NULL; + mutex_unlock(&ept->cb_lock); + + kref_put(&ept->refcount, __ept_release); } /** @@ -790,12 +819,28 @@ static void rpmsg_recv_done(struct virtqueue *rvq) /* use the dst addr to fetch the callback of the appropriate user */ mutex_lock(&vrp->endpoints_lock); + ept = idr_find(&vrp->endpoints, msg->dst); + + /* let's make sure no one deallocates ept while we use it */ + if (ept) + kref_get(&ept->refcount); + mutex_unlock(&vrp->endpoints_lock); - if (ept && ept->cb) - ept->cb(ept->rpdev, msg->data, msg->len, ept->priv, msg->src); - else + if (ept) { + /* make sure ept->cb doesn't go away while we use it */ + mutex_lock(&ept->cb_lock); + + if (ept->cb) + ept->cb(ept->rpdev, msg->data, msg->len, ept->priv, + msg->src); + + mutex_unlock(&ept->cb_lock); + + /* farewell, ept, we don't need you anymore */ + kref_put(&ept->refcount, __ept_release); + } else dev_warn(dev, "msg received with no recepient\n"); /* publish the real size of the buffer */ @@ -1040,7 +1085,7 @@ static int __init rpmsg_init(void) return ret; } -module_init(rpmsg_init); +subsys_initcall(rpmsg_init); static void __exit rpmsg_fini(void) { |