Re: stack overflow

[Andreas Dilger]

On Sep 12, 2003  18:53 +0100, Breno wrote:
> Hi ... this is my idea to check a stack overflow. What do you think ?
> 
> #define STACK_LIMIT (1024*8192)/PAGE_SIZE
> 
> int check_stack_overflow(struct task_struct *tsk)
> {
> 
>     unsigned long stack_size,stack_addr,stack_ptr;
>     int i;
> 
>          if(tsk->mm != NULL)
>          {
>                   stack_addr = tsk->mm->start_stack;
> 
>                   stack_ptr = tsk->thread.esp;
> 
>                   for(i=0; i < stack_ptr; i++)
>                   stack_addr++;
> 
>                   stack_size = (stack_addr - stack_ptr)/PAGE_SIZE;
> 
>                   if(stack_size > ( STACK_LIMIT - 1))

Well, with the exception of the fact that STACK_LIMIT is 8MB, and kernel
stacks are only 8kB (on i386)...

Also, see "do_IRQ()" (i386) for CONFIG_DEBUG_STACKOVERFLOW to see this already.

Cheers, Andreas
--
Andreas Dilger
http://sourceforge.net/projects/ext2resize/
http://www-mddsp.enel.ucalgary.ca/People/adilger/

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