[Libunwind-devel] Re: [PATCH 0/4] ARM enhancements

[Henrik Grindal Bakken]

Ken Werner <address@hidden>
writes:

> On Wednesday, March 23, 2011 9:50:05 am Henrik Grindal Bakken wrote:
>> Hi Ken,
>> 
>> This patch set works better for me, but I get a crash (SIGSEGV) when
>> trying to get backtrace from a signal handler.  I'll try to figure out
>> why...
>
> Hi Henrik
>
> I've hacked a small test but wasn't able to reproduce the segfault on my 
> system. Could you share your code or elaborate on what you did? Attached is 
> the test case I was using.

Hi again Ken,

Trying to reproduce it now, I don't see the same errors I used to.  As
long as I remember to add UNW_ARM_UNWIND_METHOD=4 (should this be the
default on arm?), I get a fairly good backtrace from signal handler.
It typically looks like this:

/tmp/libunwind-test(foo+0x40) [0xaab8]
/lib/libpthread.so.0(_pthread_cleanup_pop_restore+0x1c) [0x402497e4]
/tmp/libunwind-test(main+0x44) [0xabb4]
/lib/libc.so.6(__libc_start_main+0x120) [0x402705e0]
/tmp/libunwind-test() [0xa9e4]

Where I suppose _pthread_cleanup_pop_restore should've been bar() in
my code, but that's a) not critical, and b) possibly solvable in the
signal handler.


-- 
Henrik Grindal Bakken <address@hidden>
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