On 01/31/2012 10:04 AM, Hui Zhu wrote:
#9 0x00000000006cc8e5 in post_create_inferior (target=0x1d1e860,
from_tty=1) at ../../src/gdb/infcmd.c:431
#10 0x00000000006d479d in start_remote (from_tty=1) at
../../src/gdb/infrun.c:2309
#11 0x00000000005d80c9 in remote_start_remote (from_tty=1,
target=0x1cefce0, extended_p=0)
at ../../src/gdb/remote.c:3367
About this patch, what I do is:
1. If we try to connect an new stub, reset current_trace_status to unknown.
2. Change remote_can_download_tracepoint to if the current_trace_status
is unknown, return false.
After this patch, the tracepoint insered after:
/* Possibly the target has been engaged in a trace run started
previously; find out where things are at. */
if (remote_get_trace_status (current_trace_status ()) != -1)
{
I think that will make us handle tracepoint issue more easy.
It is caused by setting `inserted' flag improperly, but I have some
different understanding on the cause of improper-set-of-inserted-flag.
As you posted, the call stack is,
remote_start_remote
|
+--> start_remote
| |
| `--> .... [1]
`--> merge_uploaded_tracepoints
Error occurs in the callees of [1]. In fact, the `inserted' flag will
be set in merge_uploaded_tracepoints, if it has been in remote target
(See merge_uploaded_tracepoints). The intention of these bits is to
mark tracepoint bp_locations as `inserted' to avoid inserting them
again. The root cause is that we use the `inserted' flag (in calleees
of [1]) prior to setting it properly (in merge_uploaded_tracepoints), so
the fix to this problem is moving merge_uploaded_tracepoints prior to
start_remote. I drafted a patch in this way, and fixed the problem you
posted.
Patch attached is used to illustrate my thought to fix this problem. I
am not confident on it because I don't know it is correct to change the
order of function calls in remote_start_remote. The "non stop" path in
remote_start_remote is not affected by this patch. In the "stop" path,
the order of some functions call is changed, but don't know they are
equivalent.
Original Patched
start_remote merge_uploaded_tracepoints
remote_check_symbols start_remote
merge_uploaded_tracepoints remote_check_symbols