> Hi List,
>
> Recently I got into the problem that I think relates to the small size
> of kernel stack. I had a function of the following form:
>
> void func()
> {
> ...
> //Block1
> {
> struct huge_var x;
> ....
> ....
> }
> ....
> //Block2
> {
> struct huge_var y;
> ....
> ....
> }
> ....
> }
>
> The above code resulted in stack overflow. I had an understanding that
> since the scope of variables x & y are limited to their blocks only,
> the space for them will be allocated and released when the block is
> entered and exited respectively. And hence the kernel stack will not
> overflow since both x and y will not occupy memory simultaneously (one
> instance of the variable can easily fit in the kernel stack).
>
This is wrong. Although the scope is at _block_ level, all variables are
allocated on the stack at _function_ level. So, when entering func() all
variables within it, including x and y, are allocated.
> I solved this problem by having a single instance of struct huge_var
> declared immediately at function begining and reusing it in both
> blocks. But my question is when (and where) are the block scope
> variable allocated? In my previous case, were the two variables
> occupying two sperate memory areas simultaneously?
>
> Ah, I understand that I should use kernel stack sparingly ... and will do so.
> Thanks,
>
> Rajat
>
> --
> To unsubscribe from this list: send an email with
> "unsubscribe kernelnewbies" to ecartis@xxxxxxxxxxxx
> Please read the FAQ at http://kernelnewbies.org/FAQ
>
-
To unsubscribe from this list: send the line "unsubscribe linux-newbie" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.linux-learn.org/faqs
