Re: [PATCH] kdump: Fix gdb macros work work with newer and 64-bit kernels

From: Baoquan He
Date: Mon May 09 2016 - 21:37:36 EST


On 05/09/16 at 10:40am, Corey Minyard wrote:
> >>>>> define bttnobp
> >>>>> set $tasks_off=((size_t)&((struct task_struct *)0)->tasks)
> >>>>>- set $pid_off=((size_t)&((struct task_struct *)0)->pids[1].pid_list.next)
> >>>>>+ set $pid_off=((size_t)&((struct task_struct *)0)->thread_group.next)
> >>>This is a quite nice fix.
> >>>
> >>>>> set $init_t=&init_task
> >>>>> set $next_t=(((char *)($init_t->tasks).next) - $tasks_off)
> >>>>> while ($next_t != $init_t)
> >>>>> set $next_t=(struct task_struct *)$next_t
> >>>>> printf "\npid %d; comm %s:\n", $next_t.pid, $next_t.comm
> >>>>> printf "===================\n"
> >>>>>- set var $stackp = $next_t.thread.esp
> >>>>>+ set var $stackp = $next_t.thread.sp
> >>>>> set var $stack_top = ($stackp & ~4095) + 4096
> >Missed one place here. Currently the kernel stack is decided by
> >THREAD_SIZE since the definition:
> >
> >union thread_union {
> > struct thread_info thread_info;
> > unsigned long stack[THREAD_SIZE/sizeof(long)];
> >};
> >
> >Should we get the top and bottom of stack according to this now?
> >
> >Correct me if I was wrong.
>
> I think you are correct. We should use something like:
>
> set var $stack_top = ($stackp & ~(sizeof(thread_union) - 1)) +
> sizeof(thread_union)
>
> Is this what you are suggesting?

Exactly, it's cool. Thanks!