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author | Dmitry Torokhov <dmitry.torokhov@gmail.com> | 2016-03-16 02:54:45 +0300 |
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committer | Dmitry Torokhov <dmitry.torokhov@gmail.com> | 2016-03-16 02:54:45 +0300 |
commit | 245f0db0de926601353776085e6f6a4c974c5615 (patch) | |
tree | b493e9e726f4a898041f7861d0df328aa1a348a1 /drivers/hv/hv_utils_transport.c | |
parent | 24672bdfb357b91bed0ea8d432241bf7bdefc8a8 (diff) | |
parent | b562e44f507e863c6792946e4e1b1449fbbac85d (diff) | |
download | linux-245f0db0de926601353776085e6f6a4c974c5615.tar.xz |
Merge tag 'v4.5' into next
Merge with Linux 4.5 to get PROPERTY_ENTRY_INTEGER() that is needed to
fix pxa/raumfeld rotary encoder properties.
Diffstat (limited to 'drivers/hv/hv_utils_transport.c')
-rw-r--r-- | drivers/hv/hv_utils_transport.c | 130 |
1 files changed, 97 insertions, 33 deletions
diff --git a/drivers/hv/hv_utils_transport.c b/drivers/hv/hv_utils_transport.c index 6a9d80a5332d..4f42c0e20c20 100644 --- a/drivers/hv/hv_utils_transport.c +++ b/drivers/hv/hv_utils_transport.c @@ -27,11 +27,9 @@ static struct list_head hvt_list = LIST_HEAD_INIT(hvt_list); static void hvt_reset(struct hvutil_transport *hvt) { - mutex_lock(&hvt->outmsg_lock); kfree(hvt->outmsg); hvt->outmsg = NULL; hvt->outmsg_len = 0; - mutex_unlock(&hvt->outmsg_lock); if (hvt->on_reset) hvt->on_reset(); } @@ -44,10 +42,17 @@ static ssize_t hvt_op_read(struct file *file, char __user *buf, hvt = container_of(file->f_op, struct hvutil_transport, fops); - if (wait_event_interruptible(hvt->outmsg_q, hvt->outmsg_len > 0)) + if (wait_event_interruptible(hvt->outmsg_q, hvt->outmsg_len > 0 || + hvt->mode != HVUTIL_TRANSPORT_CHARDEV)) return -EINTR; - mutex_lock(&hvt->outmsg_lock); + mutex_lock(&hvt->lock); + + if (hvt->mode == HVUTIL_TRANSPORT_DESTROY) { + ret = -EBADF; + goto out_unlock; + } + if (!hvt->outmsg) { ret = -EAGAIN; goto out_unlock; @@ -68,7 +73,7 @@ static ssize_t hvt_op_read(struct file *file, char __user *buf, hvt->outmsg_len = 0; out_unlock: - mutex_unlock(&hvt->outmsg_lock); + mutex_unlock(&hvt->lock); return ret; } @@ -77,19 +82,22 @@ static ssize_t hvt_op_write(struct file *file, const char __user *buf, { struct hvutil_transport *hvt; u8 *inmsg; + int ret; hvt = container_of(file->f_op, struct hvutil_transport, fops); - inmsg = kzalloc(count, GFP_KERNEL); - if (copy_from_user(inmsg, buf, count)) { - kfree(inmsg); - return -EFAULT; - } - if (hvt->on_msg(inmsg, count)) - return -EFAULT; + inmsg = memdup_user(buf, count); + if (IS_ERR(inmsg)) + return PTR_ERR(inmsg); + + if (hvt->mode == HVUTIL_TRANSPORT_DESTROY) + ret = -EBADF; + else + ret = hvt->on_msg(inmsg, count); + kfree(inmsg); - return count; + return ret ? ret : count; } static unsigned int hvt_op_poll(struct file *file, poll_table *wait) @@ -99,6 +107,10 @@ static unsigned int hvt_op_poll(struct file *file, poll_table *wait) hvt = container_of(file->f_op, struct hvutil_transport, fops); poll_wait(file, &hvt->outmsg_q, wait); + + if (hvt->mode == HVUTIL_TRANSPORT_DESTROY) + return POLLERR | POLLHUP; + if (hvt->outmsg_len > 0) return POLLIN | POLLRDNORM; @@ -108,40 +120,68 @@ static unsigned int hvt_op_poll(struct file *file, poll_table *wait) static int hvt_op_open(struct inode *inode, struct file *file) { struct hvutil_transport *hvt; + int ret = 0; + bool issue_reset = false; hvt = container_of(file->f_op, struct hvutil_transport, fops); - /* - * Switching to CHARDEV mode. We switch bach to INIT when device - * gets released. - */ - if (hvt->mode == HVUTIL_TRANSPORT_INIT) + mutex_lock(&hvt->lock); + + if (hvt->mode == HVUTIL_TRANSPORT_DESTROY) { + ret = -EBADF; + } else if (hvt->mode == HVUTIL_TRANSPORT_INIT) { + /* + * Switching to CHARDEV mode. We switch bach to INIT when + * device gets released. + */ hvt->mode = HVUTIL_TRANSPORT_CHARDEV; + } else if (hvt->mode == HVUTIL_TRANSPORT_NETLINK) { /* * We're switching from netlink communication to using char * device. Issue the reset first. */ - hvt_reset(hvt); + issue_reset = true; hvt->mode = HVUTIL_TRANSPORT_CHARDEV; - } else - return -EBUSY; + } else { + ret = -EBUSY; + } - return 0; + if (issue_reset) + hvt_reset(hvt); + + mutex_unlock(&hvt->lock); + + return ret; +} + +static void hvt_transport_free(struct hvutil_transport *hvt) +{ + misc_deregister(&hvt->mdev); + kfree(hvt->outmsg); + kfree(hvt); } static int hvt_op_release(struct inode *inode, struct file *file) { struct hvutil_transport *hvt; + int mode_old; hvt = container_of(file->f_op, struct hvutil_transport, fops); - hvt->mode = HVUTIL_TRANSPORT_INIT; + mutex_lock(&hvt->lock); + mode_old = hvt->mode; + if (hvt->mode != HVUTIL_TRANSPORT_DESTROY) + hvt->mode = HVUTIL_TRANSPORT_INIT; /* * Cleanup message buffers to avoid spurious messages when the daemon * connects back. */ hvt_reset(hvt); + mutex_unlock(&hvt->lock); + + if (mode_old == HVUTIL_TRANSPORT_DESTROY) + hvt_transport_free(hvt); return 0; } @@ -168,6 +208,7 @@ static void hvt_cn_callback(struct cn_msg *msg, struct netlink_skb_parms *nsp) * Switching to NETLINK mode. Switching to CHARDEV happens when someone * opens the device. */ + mutex_lock(&hvt->lock); if (hvt->mode == HVUTIL_TRANSPORT_INIT) hvt->mode = HVUTIL_TRANSPORT_NETLINK; @@ -175,6 +216,7 @@ static void hvt_cn_callback(struct cn_msg *msg, struct netlink_skb_parms *nsp) hvt_found->on_msg(msg->data, msg->len); else pr_warn("hvt_cn_callback: unexpected netlink message!\n"); + mutex_unlock(&hvt->lock); } int hvutil_transport_send(struct hvutil_transport *hvt, void *msg, int len) @@ -182,7 +224,8 @@ int hvutil_transport_send(struct hvutil_transport *hvt, void *msg, int len) struct cn_msg *cn_msg; int ret = 0; - if (hvt->mode == HVUTIL_TRANSPORT_INIT) { + if (hvt->mode == HVUTIL_TRANSPORT_INIT || + hvt->mode == HVUTIL_TRANSPORT_DESTROY) { return -EINVAL; } else if (hvt->mode == HVUTIL_TRANSPORT_NETLINK) { cn_msg = kzalloc(sizeof(*cn_msg) + len, GFP_ATOMIC); @@ -197,18 +240,26 @@ int hvutil_transport_send(struct hvutil_transport *hvt, void *msg, int len) return ret; } /* HVUTIL_TRANSPORT_CHARDEV */ - mutex_lock(&hvt->outmsg_lock); + mutex_lock(&hvt->lock); + if (hvt->mode != HVUTIL_TRANSPORT_CHARDEV) { + ret = -EINVAL; + goto out_unlock; + } + if (hvt->outmsg) { /* Previous message wasn't received */ ret = -EFAULT; goto out_unlock; } hvt->outmsg = kzalloc(len, GFP_KERNEL); - memcpy(hvt->outmsg, msg, len); - hvt->outmsg_len = len; - wake_up_interruptible(&hvt->outmsg_q); + if (hvt->outmsg) { + memcpy(hvt->outmsg, msg, len); + hvt->outmsg_len = len; + wake_up_interruptible(&hvt->outmsg_q); + } else + ret = -ENOMEM; out_unlock: - mutex_unlock(&hvt->outmsg_lock); + mutex_unlock(&hvt->lock); return ret; } @@ -239,7 +290,7 @@ struct hvutil_transport *hvutil_transport_init(const char *name, hvt->mdev.fops = &hvt->fops; init_waitqueue_head(&hvt->outmsg_q); - mutex_init(&hvt->outmsg_lock); + mutex_init(&hvt->lock); spin_lock(&hvt_list_lock); list_add(&hvt->list, &hvt_list); @@ -265,12 +316,25 @@ err_free_hvt: void hvutil_transport_destroy(struct hvutil_transport *hvt) { + int mode_old; + + mutex_lock(&hvt->lock); + mode_old = hvt->mode; + hvt->mode = HVUTIL_TRANSPORT_DESTROY; + wake_up_interruptible(&hvt->outmsg_q); + mutex_unlock(&hvt->lock); + + /* + * In case we were in 'chardev' mode we still have an open fd so we + * have to defer freeing the device. Netlink interface can be freed + * now. + */ spin_lock(&hvt_list_lock); list_del(&hvt->list); spin_unlock(&hvt_list_lock); if (hvt->cn_id.idx > 0 && hvt->cn_id.val > 0) cn_del_callback(&hvt->cn_id); - misc_deregister(&hvt->mdev); - kfree(hvt->outmsg); - kfree(hvt); + + if (mode_old != HVUTIL_TRANSPORT_CHARDEV) + hvt_transport_free(hvt); } |