[Buildroot] Can't debug threaded app on ARM920 (SIG32)
grant.b.edwards at gmail.com
Mon Jun 22 16:31:06 UTC 2009
I'm trying to debug a threaded application using gdbserver on
an ARM920T platform (Atmel AT91RM9200 eval board), and I'm not
having much luck. Whenver a new thread is started, I see a
Here's a typical session:
GNU gdb 6.8
This GDB was configured as "--host=i386-pc-linux-gnu --target=arm-linux-uclibc".
[New Thread 797]
0x40000930 in _start ()
(gdb) break 62
Breakpoint 1 at 0x8dc8: file hello.c, line 62.
Breakpoint 1, main () at hello.c:62
62 s = pthread_create(tid+i, attrp, thread, (void*)i); abort_if_error(s);
Program received signal SIG32, Real-time event 32.
0x400445d4 in ?? ()
(gdb) info thread
[New Thread 798]
[New Thread 799]
3 Thread 799 0x40065700 in ?? ()
2 Thread 798 0x40043918 in ?? ()
* 1 Thread 797 0x400445d4 in ?? ()
warning: Couldn't restore frame in current thread, at frame 0
0x400445d4 in ?? ()
I've tried both NPTL and Linuxthreads, both act the same.
I've verifed using strace that target gdbserver is finding
libthread_db.so and that the dev-host gdb is finding the
target-arch .so files. I've verified that the target-arch
libpthread .so files aren't stripped.
Here are config items contains the string "thread" in my
.config files (using NPTL):
$ find . -name .config | xargs grep -i thread
./toolchain_build_arm/uClibc-0.9.30.1/.config:# HAS_NO_THREADS is not set
./.config:# BR2_PTHREADS_NONE is not set
./.config:# BR2_PTHREADS is not set
./.config:# BR2_PTHREADS_OLD is not set
I've spent hours reading mailing-list postings and can't find
_any_ real information on how multi-threaded debugging is
supposed to work or what causes the SIG32. All I found is
people complaining about it as early as 2002 and as recently as
a couple weeks ago. Some of them eventually get it to work,
So far, I haven't even been able to narrow down which gdb
(server or client) is broken. I've posted questions to the gdb
mailing list, and haven't gotten any response there.
[I've also tried the same exercise on a PPC platform (using
LTIB/glibc instead of buildroot), and those results were even
worse: gdb seemed to be completely unaware of threads.]
Can somebody point me to _any_ hard information on how to get
thread debugging working using gdbserver?
Grant Edwards grante Yow! Do you have exactly
at what I want in a plaid
visi.com poindexter bar bat??
More information about the buildroot