(gdb) bt
bt
Backtrace stopped: previous frame inner to this frame (corrupt stack?)
(gdb) frame 5
frame 5
293 if (PREDICT_FALSE (rxvq->last_avail_idx == rxvq->avail->idx))
(gdb) p *rxvq
p *rxvq
$3 = {cacheline0 = 0x7f290bcadd80 "\377\003", qsz_mask = 1023, last_avail_idx = 0, last_used_idx = 0, n_since_last_int = 0, desc = 0x0, avail = 0x0, used = 0x0, int_deadline = 0, started = 1 '\001', enabled = 1 '\001', log_used = 0 '\000', cacheline1 = 0x7f290bcaddc0 "\377\377\377\377\016", errfd = -1, callfd_idx = 14, kickfd_idx = 19, log_guest_addr =
5151049792, mode = 0}
The crash is because we access the null pointer rxvq->avail,
which is supposed to be derived from the mmap informed by the driver.
We fixed a similar issue before in
https://gerrit.fd.io/r/#/c/14545/
The reason was the driver ummaps the memory without doing the disconnect in
SR-IOV environment. The fixed was applied to the RX path. Now it happens in the
TX path. We just need to apply the same check in the TX path.
Change-Id: I7b1dfc96797cb5b52845bc6cec09a8c5d4325280
Signed-off-by: Steven <sluong@cisco.com>
VHOST_VRING_IDX_RX (*vec_elt_at_index
(vui->per_cpu_tx_qid, thread_index));
rxvq = &vui->vrings[qid];
+ if (PREDICT_FALSE (rxvq->avail == 0))
+ {
+ error = VHOST_USER_TX_FUNC_ERROR_MMAP_FAIL;
+ goto done3;
+ }
+
if (PREDICT_FALSE (vui->use_tx_spinlock))
vhost_user_vring_lock (vui, qid);