Re: stack overflow?

[Christian Widmer]

On Wednesday 26 September 2001 15:29, you wrote:
> Christian Widmer wrote:
> > hi
> >
> > i saw very strange behaviour when debuging my modules and i start to
> > think about stack overflow. i know that the kernel stack of eache process
> > is some what smaller than 8KB. but how big is the kernelstack during
> > interrupt time when executing tasklets?
>
> Depends on the architecture, but on the x86 there is no stack switch
> when you receive an interrupt in kernel mode.  Thus, if too many
> interrupts occur you could potentially overflow the stack.  If
> interrupted from user mode the stack switches to the top of the kernel
> stack.

thanks
i could verify that it was a stackoverflow. but this was due to an 
unexpected behaviour of gcc not because of too may interrupts :) 
i realiesd that when i had a look at the assemby output of my code. 
i had a macro that defined its local variables (256 byte). this macro 
was used n times and gcc allocates n * 256 bytes at the function entry 
point also it actualy only needs 256 byte. is his allocation strategy 
not silly?

chris