Re: Trying to debug segfault

[Orion Poplawski <orion@xxxxxxxx>]

On 01/25/2018 10:57 AM, Orion Poplawski wrote:
> I'm trying to debug a segfault in libssh used by x2goclient.

The actual segfault I'm seeing is here:

2018/01/25 11:29:49.974392, 3] ssh_socket_unbuffered_write:  Enabling POLLOUT
for socket

Program received signal SIGSEGV, Segmentation fault.
0x00007ffff7180f5b in ssh_poll_set_events (p=0x7fffdc00c1a0, events=4)
    at /usr/src/debug/master/src/poll.c:349
349         p->ctx->pollfds[p->x.idx].events = events;
(gdb) print *p
$1 = {ctx = 0x7fffdc00e410, session = 0x7fffdc003190, x = {fd = 18, idx = 18},
events = 4,
  lock = 0, cb = 0x7ffff7184700 <ssh_socket_pollcallback>, cb_data =
0x7fffdc003ae0}
(gdb) print *p->ctx
$2 = {pollptrs = 0x4d70aaec309957, pollfds = 0x45, polls_allocated =
140736884427952,
  polls_used = 0, chunk_size = 20}

So pollfds is obviously not a valid pointer here.


-- 
Orion Poplawski
Manager of NWRA Technical Systems          720-772-5637
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