Bug in dumper

[Egor Duda]

Ronald Landheer-Cieslak wrote:
>>Does dumper.exe work?

Well, i should have answered this, but unfortunately, i have no access 
to windows machine right now to debug, or even verify this.

>>Upon execution I see the following in the cygwin console:
>>  $ ./div.exe
>>        7 [main] div 2296 handle_exceptions: Error while dumping state (probably corrupted stack)
>>  Arithmetic exception (core dumped)
>>
>>In the cmd.exe console window that dumper.bat starts I see the following:
>>  C:\cygwin\home\jlambert>dumper.exe -d C:/cygwin/home/jlambert/div.exe 1884
>>  dumping process #1884 to div.exe.core
>>  setting bfd architecture: No error

Well, this is a strange line. This last line of dumper's output 
indicates than call to bfd_set_arch_mach(abfd, bfd_arch_i386, 0) havs 
returned non-zero status, which should indicate an error (if i 
understand things correctly), yet bfd_perror called immediately 
afterwards has printed "No error" message.

This means that either i'm wrong about my assumptions about 
bfd_set_arch_mach() and its return, or there's a bug in binutils. It 
should be quite easy to debug, though, for those who have a cygwin 
toolchain installed. Just build dumper with debug info (this will 
require building bfd alongside), start any innocent process, say, bash, 
get its pid and then run 'dumper -d c:/cygwin/bin/bash.exe <bash_pid>' 
under gdb. This should reveal what status is returned by 
bfd_set_arch_mach, and why.

egor.