d/freebsd-skq
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

hyperv/vmbus: Return EISCONN if the bufring GPADL can't be disconnected.

Browse Source 
So that the callers of vmbus_chan_open_br() could handle the passed in
bufring memory properly.

MFC after:	1 week
Sponsored by:	Microsoft
Differential Revision:	https://reviews.freebsd.org/D8569
This commit is contained in:
Sepherosa Ziehau 2016-11-25 07:24:11 +00:00
parent 12fbfdab73
commit 32ab625a61
2 changed files with 37 additions and 2 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

11
sys/dev/hyperv/include/vmbus.h
View File

@ -129,6 +129,17 @@ vmbus_get_channel(device_t dev)
return device_get_ivars(dev);
}
/*
* vmbus_chan_open_br()
* Return values:
* 0 Succeeded.
* EISCONN Failed, and the memory passed through 'br' is still
* connected. Callers must _not_ free the the memory
* passed through 'br', if this error happens.
* other values Failed. The memory passed through 'br' is no longer
* connected. Callers are free to do anything with the
* memory passed through 'br'.
*/
int vmbus_chan_open(struct vmbus_channel *chan,
int txbr_size, int rxbr_size, const void *udata, int udlen,
vmbus_chan_callback_t cb, void *cbarg);

28
sys/dev/hyperv/vmbus/vmbus_chan.c
View File

@ -324,7 +324,21 @@ vmbus_chan_open(struct vmbus_channel *chan, int txbr_size, int rxbr_size,
error = vmbus_chan_open_br(chan, &cbr, udata, udlen, cb, cbarg);
if (error) {
hyperv_dmamem_free(&chan->ch_bufring_dma, chan->ch_bufring);
if (error == EISCONN) {
/*
* XXX
* The bufring GPADL is still connected; abandon
* this bufring, instead of having mysterious
* crash or trashed data later on.
*/
vmbus_chan_printf(chan, "chan%u bufring GPADL "
"is still connected upon channel open error; "
"leak %d bytes memory\n", chan->ch_id,
txbr_size + rxbr_size);
} else {
hyperv_dmamem_free(&chan->ch_bufring_dma,
chan->ch_bufring);
}
chan->ch_bufring = NULL;
}
return (error);
@ -458,7 +472,17 @@ failed:
sysctl_ctx_free(&chan->ch_sysctl_ctx);
vmbus_chan_clear_chmap(chan);
if (chan->ch_bufring_gpadl != 0) {
vmbus_chan_gpadl_disconnect(chan, chan->ch_bufring_gpadl);
int error1;
error1 = vmbus_chan_gpadl_disconnect(chan,
chan->ch_bufring_gpadl);
if (error1) {
/*
* Give caller a hint that the bufring GPADL is still
* connected.
*/
error = EISCONN;
}
chan->ch_bufring_gpadl = 0;
}
atomic_clear_int(&chan->ch_stflags, VMBUS_CHAN_ST_OPENED);