Re: [gdbserver] Problems trying to resume dead threads

["Ulrich Weigand" <uweigand at de dot ibm dot com>]

Daniel Jacobowitz wrote:

> I can reproduce this problem by using the binary from killed.exp and
> running strace on gdbserver.  I can also reproduce it on an embedded
> ARM target by running killed.exp.  I can't reproduce it on my desktop
> running killed.exp, which suggests this is normally hidden by
> scheduler decisions - you need a long enough gap between the two
> PTRACE_CONT's.
> 
> What do you think of this change?  Ideally, we could wait with WNOHANG
> at this point to check for the exit case, but we'd have to restructure
> a bit of the event loop to handle pending status == exited.

Hmm, still fails with my Cell test case like this:
writing register 25: No such process
ptrace(regsets_fetch_inferior_registers) PID=14241: No such process
reading register 0: No such process

The initial error happens in usr_store_inferior_registers called via
the regcache_invalidate_one call in linux_resume_one_process, just 
before the location you modified.  Whether this writes anything 
probably depends on target properties like decr_pc_after_break ...
Ignoring ESRCH in usr_store_inferior_registers as well seems to 
fix the problem for me.

In any case, I'm not sure why usr_store_inferior_registers errors
out ... the parallel regsets_store_inferior_registers only gives
a warning in this case.

Bye,
Ulrich

-- 
  Dr. Ulrich Weigand
  GNU Toolchain for Linux on System z and Cell BE
  Ulrich.Weigand@de.ibm.com