backtracing threaded ARM core

[Nickolay Vinogradov <nickolay@protei.ru>]

Hi,

I'm having trouble with backtracing threaded ARM applications.
My simple application create thread, which call func1() -> func2() -> 
func3() and then sleep();

If I kill this thread(with SEGV) while sleep, and look with gdb, I see 
only last function nanosleep(), and unknown __pthread_enable_asynccancel().

(gdb) bt
#0  0x01d4cde4 in nanosleep ()
#1  0x01d4be5c in __pthread_enable_asynccancel () at cancellation.c:42
#2  0xbee4d9b4 in ?? ()
Current language:  auto; currently asm

When sleep() replaced in the code with while(1), then I can see the full 
backtrace:
#0  0x00008260 in func3 (a=<value optimized out>) at core_test.cpp:66
#1  0x0000826c in func2 (a=0x492edfa7) at core_test.cpp:57
#2  0x0000828c in func1 (a=0x492edfa7) at core_test.cpp:49
#3  0x000082c4 in ThreadFunction () at core_test.cpp:45
#4  0x00008908 in start_thread (arg=<value optimized out>) at 
pthread_create.c:300
#5  0x00026770 in clone ()
Backtrace stopped: frame did not save the PC

Repeated with:
gcc-4.2.1(armv5b-softfloat-linux) + glibc-2.5
gcc-4.3.2(armeb-none-linux-gnueabi) + glibc-2.8

Could you please help me out ?

-- 
Nickolay VInogradov