| Message ID | 1412749679-27076-4-git-send-email-yao@codesourcery.com |
|---|---|
| State | New |
| Headers | show |
On 10/08/2014 07:27 AM, Yao Qi wrote: > Nowadays, we are using command "tstatus" to send a packet to GDBserver > in order to check the connection. However, on the target doesn't > support tracepoint, the following error is emitted before sending any > packet to GDBserver. > > tstatus^M > Trace can not be run on this target.^M > (gdb) FAIL: gdb.server/server-kill.exp: tstatus > > We have to choose other commands which exists on different targets, and > send a RSP packet to GDBserver. "monitor set debug 0" is a good one. > Hmm, are you sure GDB didn't really send any packet to GDBserver? That error is printed by trace_status_command, but only after calling target_get_trace_status, which seems to me should be sending a packet. remote_get_trace_status's exception swallowing should be letting TARGET_CLOSE_ERROR pass through. Is that not working? I'm a bit confused because it seems like if that didn't work, we should see a "qTStatus:..." error line in the logs. So what is preventing the packet from being sent? Thanks, Pedro Alves
Pedro Alves <palves@redhat.com> writes: > That error is printed by trace_status_command, but only after calling > target_get_trace_status, which seems to me should be sending a packet. > > remote_get_trace_status's exception swallowing should be > letting TARGET_CLOSE_ERROR pass through. Is that not working? > I'm a bit confused because it seems like if that didn't work, > we should see a "qTStatus:..." error line in the logs. > > So what is preventing the packet from being sent? qTStatus is disabled after receiving the empty reply during connecting to the remote target. (gdb) set debug remote 1 (gdb) target remote :4444 ... Sending packet: $qTStatus#49...Packet received: Packet qTStatus (trace-status) is NOT supported ... (gdb) show remote trace-status-packet Support for the `qTStatus' packet is auto-detected, currently disabled. When the test executes command "tstatus" again, remote_get_trace_status returns -1 at the very beginning, if (packet_support (PACKET_qTStatus) == PACKET_DISABLE) return -1; so no RSP packet is sent out. (gdb) set debug remote 1 (gdb) tstatus Trace can not be run on this target.
On 10/09/2014 04:01 AM, Yao Qi wrote: > Pedro Alves <palves@redhat.com> writes: > >> That error is printed by trace_status_command, but only after calling >> target_get_trace_status, which seems to me should be sending a packet. >> >> remote_get_trace_status's exception swallowing should be >> letting TARGET_CLOSE_ERROR pass through. Is that not working? >> I'm a bit confused because it seems like if that didn't work, >> we should see a "qTStatus:..." error line in the logs. >> >> So what is preventing the packet from being sent? > > qTStatus is disabled after receiving the empty reply during connecting > to the remote target. Ah, thanks. I missed that we request the trace status on connection. So I think we should do "set remote trace-status-packet on" before the "tstatus". I know that the test originally didn't use "tstatus", but it's really the packet we should be testing for exercising that remote_get_trace_status's exception swallowing code, which was very much related to the original bug this test covered, see: https://sourceware.org/bugzilla/show_bug.cgi?id=15275 https://sourceware.org/ml/gdb-patches/2013-03/msg00691.html Thanks, Pedro Alves
diff --git a/gdb/testsuite/gdb.server/server-kill.exp b/gdb/testsuite/gdb.server/server-kill.exp index 0f808a9..a2e65a4 100644 --- a/gdb/testsuite/gdb.server/server-kill.exp +++ b/gdb/testsuite/gdb.server/server-kill.exp @@ -53,4 +53,4 @@ remote_exec target "kill -9 $server_pid" # Force GDB to talk with GDBserver, so that we can get the # "connection closed" error. -gdb_test "tstatus" {Remote connection closed|Remote communication error\. Target disconnected\.: Connection reset by peer\.} +gdb_test "monitor set debug 0" {Remote connection closed|Remote communication error\. Target disconnected\.: Connection reset by peer\.}