Re: [PATCH 05/12] Handle reinsert breakpoints for vforked child

[Pedro Alves <palves at redhat dot com>]

On 06/02/2016 10:30 AM, Yao Qi wrote:
> When a thread is doing step-over with reinsert breakpoint, and the
> instruction executed is a syscall doing vfork, both parent and child
> share the memory, so the reinsert breakpoint in the space is visible
> to both of them.  Also, removing the reinsert breakpoints from the
> child will effectively remove them from the parent.  We should
> carefully manipulate reinsert breakpoints for both processes.
> 
> What we are doing here is that
> 
>  - uninsert reinsert breakpoints from the parent before cloning the
>    breakpoint list.  We use "uninsert" instead of "remove", because
>    we need to "reinsert" them back after vfork is done.  In fact,
>    "uninsert" removes them from both child and parent process space.
>  - reinsert breakpoints in parent process are still copied to child's
>    breakpoint list,
>  - remove them from child's breakpoint list as what we did for fork,
>    at this point, reinsert breakpoints are removed from the child and
>    the parent, but they are still tracked by the parent's breakpoint
>    list,
>  - once vfork is done, "reinsert" them back to the parent,
> 
> gdb/gdbserver:
> 
> 2016-05-26  Yao Qi  <yao.qi@linaro.org>
> 
> 	* linux-low.c (handle_extended_wait): Call
> 	uninsert_reinsert_breakpoints for the parent process.  Remove
> 	reinsert breakpoints from the child process.  Reinsert them to
> 	the parent process when vfork is done.
> 	* mem-break.c (uninsert_reinsert_breakpoints): New function.
> 	(reinsert_reinsert_breakpoints): New function.
> 	* mem-break.h (uninsert_reinsert_breakpoints): Declare
> 	(reinsert_reinsert_breakpoints): Declare.
> 
> gdb/testsuite:
> 
> 2016-05-26  Yao Qi  <yao.qi@linaro.org>
> 
> 	* gdb.base/step-over-fork-1.exp: Extend the test for vfork.

OK.

Thanks,
Pedro Alves