Re: thread-debuging with gdbserver on ARM/NPTL

Luotao Fu
2006-10-26T09:55:38Z

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Hi,

On Wed, Oct 25, 2006 at 11:03:44AM -0400, Daniel Jacobowitz wrote:
> On Wed, Oct 25, 2006 at 04:45:29PM +0200, Robert Schwebel wrote:
> > Here are some more details about the problem. It turned out that it
> > works if you link against libpthread dynamically and doesn't with
> > -static.
>
> Oh, right. Thread debugging of static applications using NPTL is
> particularly problematic. Take a look at this, for starters:
>
> http://sourceware.org/bugzilla/show_bug.cgi?id=2696

We built a Toolchain with gcc4.1.1+glibc2.5+gdb-6.5.50.20061025 using
the patch posted on
http://sourceware.org/ml/libc-alpha/2006-03/msg00014.html and did the
same test as already described in robert's mail again. Unluckiely the
problems with static binary seems to still consist. On the host
side gdb would stuck at first continue, while on the target side
gdbserver prints something like "Cannot enable thread event reporting
for [PID of the testapp]: generic error".

I however noticed that the test can be run if there's no symboltable
given on the host side. (say gdb is started without any parameter or
arguments) In this case I can process between the continues sending
SIGINT.

I logged the outputs and used commands to a log file and enclose it in
the attachment.
>
> --
> Daniel Jacobowitz
> CodeSourcery

Regards
Luotao Fu
--
Dipl.-Ing. Luotao Fu | http://www.pengutronix.de
Pengutronix - Linux Solutions for Science and Industry
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gdb (host):

lfu@himalia:/ptx/work/mkl/sprecher/testcases/test_case_3 /opt/OSELAS.Toolchain-trunk/arm-ep93xx-linux-gnueabi/gcc-4.1.1-glibc-2.5-staticfix/bin/arm-ep93xx-linux-gnueabi-gdb gdb_test
GNU gdb 6.5.50.20061025
Copyright (C) 2006 Free Software Foundation, Inc.
GDB is free software, covered by the GNU General Public License, and you are
welcome to change it and/or distribute copies of it under certain conditions.
Type "show copying" to see the conditions.
There is absolutely no warranty for GDB. Type "show warranty" for details.
This GDB was configured as "--host=i686-host-linux-gnu --target=arm-ep93xx-linux-gnueabi"...
Breakpoint 1 at 0x8294: file gdb_test.c, line 32.
Breakpoint 2 at 0x8340: file gdb_test.c, line 49.
Breakpoint 3 at 0x83ec: file gdb_test.c, line 66.
Breakpoint 4 at 0x8498: file gdb_test.c, line 83.
Breakpoint 5 at 0x8550: file gdb_test.c, line 101.
Breakpoint 6 at 0x8568: file gdb_test.c, line 102.
Breakpoint 7 at 0x8580: file gdb_test.c, line 103.
Breakpoint 8 at 0x8598: file gdb_test.c, line 104.
0x00008110 in _start ()
Ignoring packet error, continuing...
warning: Invalid remote reply: qSymbol:5f5f6e70746c5f6c6173745f6576656e74
Interrupted while waiting for the program.
Give up (and stop debugging it)? (y or n) [answered Y; input not from terminal]

gdbserver (testboard):

root@testboard:~> gdbserver 192.168.23.1:2345 gdb_test
Process gdb_test created; pid = 365
Listening on port 2345
Remote debugging from host 192.168.23.1
Cannot enable thread event reporting for 365: generic error
input_interrupt, count = 0 c = 0 ('')
readchar: Got EOF
putpkt(read): Got EOF
thread getmsg err: debugger service failed
Segmentation fault

#############################################################################################

gdb(host)
malia:/ptx/work/mkl/sprecher/testcases/test_case_3 /opt/OSELAS.Toolchain-trunk/arm-ep93xx-linux-gnueabi/gcc-4.1.1-glibc-2.5-staticfix/bin/arm-ep93xx-linux-gnueabi-gdb
GNU gdb 6.5.50.20061025
Copyright (C) 2006 Free Software Foundation, Inc.
GDB is free software, covered by the GNU General Public License, and you are
welcome to change it and/or distribute copies of it under certain conditions.
Type "show copying" to see the conditions.
There is absolutely no warranty for GDB. Type "show warranty" for details.
This GDB was configured as "--host=i686-host-linux-gnu --target=arm-ep93xx-linux-gnueabi".
No symbol table is loaded. Use the "file" command.
No symbol table is loaded. Use the "file" command.
No symbol table is loaded. Use the "file" command.
No symbol table is loaded. Use the "file" command.
No symbol table is loaded. Use the "file" command.
No symbol table is loaded. Use the "file" command.
No symbol table is loaded. Use the "file" command.
No symbol table is loaded. Use the "file" command.
0x00008110 in ?? ()

Program received signal SIGINT, Interrupt.
0x00021774 in ?? ()
No shared libraries loaded at this time.

Program received signal SIGINT, Interrupt.
0xbeeaf9b4 in ?? ()

Program received signal SIGINT, Interrupt.
0x00021774 in ?? ()

Program received signal SIGINT, Interrupt.
0xbeeaf9b4 in ?? ()
1 Thread 367 0xbeeaf9b4 in ?? ()
warning: Couldn't restore frame in current thread, at frame 0
0xbeeaf9b4 in ?? ()

Program received signal SIGINT, Interrupt.
0x00021774 in ?? ()

Program received signal SIGINT, Interrupt.
0xbeeaf9b4 in ?? ()

Program received signal SIGINT, Interrupt.
0xbeeaf9a8 in ?? ()

Program received signal SIGINT, Interrupt.
0xbeeaf99c in ?? ()
The program is running. Exit anyway? (y or n) [answered Y; input not from terminal]

gdbserver (testboard):

root@phyCORE-PXA270:~> gdbserver 192.168.23.1:2345 gdb_test
Process gdb_test created; pid = 367
Listening on port 2345
Remote debugging from host 192.168.23.1
main
My name is 1. thread 1
My name is 2. thread 2
My name is 3. thread 3
My name is 4. thread 4
My name is 1. thread 1
My name is 2. thread 2
My name is 3. thread 3
My name is 4. thread 4
main
My name is 1. thread 1
My name is 2. thread 2
My name is 3. thread 3
My name is 4. thread 4
My name is 1. thread 1
My name is 2. thread 2
My name is 3. thread 3
My name is 4. thread 4
main
My name is 1. thread 1
My name is 2. thread 2
My name is 3. thread 3
My name is 4. thread 4
My name is 1. thread 1
My name is 2. thread 2
My name is 3. thread 3
My name is 4. thread 4
main
My name is 1. thread 1
My name is 2. thread 2
My name is 3. thread 3
My name is 4. thread 4
My name is 1. thread 1
My name is 2. thread 2
My name is 3. thread 3
My name is 4. thread 4
Killing inferior

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