[Bug gdb/13830] New: Can't cross-debug threads: arm target,gdbserver, gdb on cygwin

["richaw at gmail dot com" <sourceware-bugzilla at sourceware dot org>]

http://sourceware.org/bugzilla/show_bug.cgi?id=13830

             Bug #: 13830
           Summary: Can't cross-debug threads: arm target, gdbserver, gdb
                    on cygwin
           Product: gdb
           Version: 7.4
            Status: NEW
          Severity: normal
          Priority: P2
         Component: gdb
        AssignedTo: unassigned@sourceware.org
        ReportedBy: richaw@gmail.com
    Classification: Unclassified


I have just compiled gdb and gdbserver 7.4. I had the same problem with
7.1, and hoped 7.4 would work.
The host is cygwin, 64-bit win7.
I compiled gdb with --target=arm-unknown-linux
I compiled gdbserver with --host arm-unknown-linux (but see
Bug ID 13829)

I start gdbserver on the arm target

50:/mnt/home/rw # ./gdbserver74 x:12 nsrun xx
Process nsrun created; pid = 341
Listening on port 12

I start gdb on the host and run the program

rw@seven /cygdrive/c/local/artisan/cx/run
$ (cd arm; ./gdb74 nsrun)
GNU gdb (GDB) 7.4
Copyright (C) 2012 Free Software Foundation, Inc.
License GPLv3+: GNU GPL version 3 or later <http://gnu.org/licenses/gpl.html>
This is free software: you are free to change and redistribute it.
There is NO WARRANTY, to the extent permitted by law.  Type "show copying"
and "show warranty" for details.
This GDB was configured as "--host=i686-pc-cygwin --target=arm-unknown-linux".
For bug reporting instructions, please see:
<http://www.gnu.org/software/gdb/bugs/>...
Reading symbols from /cygdrive/c/local/artisan/cx/run/arm/nsrun...done.
(gdb) c
The program is not being run.
(gdb) tr0
warning: Unable to find dynamic linker breakpoint function.
GDB will be unable to debug shared library initializers
and track explicitly loaded dynamic code.
0x2aaaba70 in ?? ()
(gdb) c
Continuing.
Cannot access memory at address 0x0

Program received signal SIG32, Real-time event 32.
0x2acad9e8 in ?? ()
(gdb) c
Continuing.

I observe the target running. I take control and
set a breakpoint in the spawned thread. When the
breakpoint is hit, nothing makes sense.


Program received signal SIGINT, Interrupt.
0x00020b20 in std::vector<Coupler*, std::allocator<Coupler*> >::size (
    this=0x8561c)
    at
/opt/crosstool/gcc-3.3.4-glibc-2.3.2/arm-unknown-linux-gnu/include/c++/3.3.4/bits/stl_vector.h:415
415           size() const { return size_type(end() - begin()); }
(gdb) b network.cpp:165
Breakpoint 1 at 0x64090: file network.cpp, line 165.
(gdb) c
Continuing.

Program received signal SIGTRAP, Trace/breakpoint trap.
0x2aad3410 in ?? ()
(gdb) bt
#0  0x2aad3410 in ?? ()
#1  0x2aacc458 in ?? ()
#2  0x2aacc458 in ?? ()
#3  0x2aacc458 in ?? ()
#4  0x2aacc458 in ?? ()
#5  0x2aacc458 in ?? ()
#6  0x2aacc458 in ?? ()
#7  0x2aacc458 in ?? ()
#8  0x2aacc458 in ?? ()
#9  0x2aacc458 in ?? ()
#10 0x2aacc458 in ?? ()
#11 0x2aacc458 in ?? ()
#12 0x2aacc458 in ?? ()
#13 0x2aacc458 in ?? ()
#14 0x2aacc458 in ?? ()
#15 0x2aacc458 in ?? ()
#16 0x2aacc458 in ?? ()
#17 0x2aacc458 in ?? ()
#18 0x2aacc458 in ?? ()
#19 0x2aacc458 in ?? ()
#20 0x2aacc458 in ?? ()
#21 0x2aacc458 in ?? ()
#22 0x2aacc458 in ?? ()
---Type <return> to continue, or q <return> to quit---

If I just continue, I find that the thread is no
longer running. The mainline continues normally.

Note: The arm computer is a Cirrus EP9302 ARM9 CPU
Note: Breakpoints work fine on the mainline code.

Note: on target,
50:/mnt/home/rw # uname -a
Linux ts7200 2.4.26-ts9 #151 Mon Feb 13 16:01:46 MST 2006 armv4l unknown
50:/mnt/home/rw #

This is the kernel supplied by embeddedarm.com for the
ts-7250 embedded computer.

Response to threads commands, while there is definitely
a second thread running:

(gdb) info threads
  Id   Target Id         Frame
* 1    Thread 346        0x000358f4 in
iterator<std::random_access_iterator_tag, TimeEvent*, int, TimeEvent* const*,
TimeEvent* const&>::iterator (
    this=0x7ffffd98)
    at
/opt/crosstool/gcc-3.3.4-glibc-2.3.2/arm-unknown-linux-gnu/include/c++/3.3.4/bits/stl_iterator.h:593
(gdb) thread 1
[Switching to thread 1 (Thread 346)]
#0  0x000358f4 in iterator<std::random_access_iterator_tag, TimeEvent*, int,
TimeEvent* const*, TimeEvent* const&>::iterator (this=0x7ffffd98)
    at
/opt/crosstool/gcc-3.3.4-glibc-2.3.2/arm-unknown-linux-gnu/include/c++/3.3.4/bits/stl_iterator.h:593
593           __normal_iterator(const _Iterator& __i) : _M_current(__i) { }
(gdb)

-- 
Configure bugmail: http://sourceware.org/bugzilla/userprefs.cgi?tab=email
------- You are receiving this mail because: -------
You are on the CC list for the bug.