Odd stacksize problem

[Adam Hoka <adam.hoka%gmail.com@localhost>]

Hello!

While making the webkit-gtk package, I have encountered an odd issue:

Using the login.conf below and running the example code (mostly taken from
WebKit, also in KDE) results in a segmentation fault (i386/4.99.72).

After some looking it seems increasing the stack size to 8M makes it overlap
with something else. So the area returned does not belong to the application,
only a part of it.

I am not aware of the details of how does and should it work,
but this seems a bug to me. Please correct me if I'm wrong.

=======
login.conf
=======

default:\
       :path=/usr/bin /bin /usr/sbin /sbin /usr/X11R6/bin /usr/pkg/bin 
/usr/pkg/sbin /usr/local/bin:\
       :umask=022:\
       :datasize-max=512M:\
       :datasize-cur=256M:\
       :maxproc-max=256:\
       :maxproc-cur=128:\
       :openfiles-cur=512:\
       :stacksize-cur=8M:\
       :memoryuse=256M:

=======
test.c
=======

#include <stdio.h>
#include <pthread.h>
 
int
main()
{
        static void* stackBase = 0;
        static size_t stackSize = 0;
        pthread_t thread = pthread_self();
        char    *p;
        pthread_attr_t sattr;
 
        pthread_attr_init(&sattr);
        pthread_attr_get_np(thread, &sattr);
        pthread_attr_getstack(&sattr, &stackBase, &stackSize);
        pthread_attr_destroy(&sattr);
 
        printf("stack base address: %x\n", stackBase);
        printf("stack size:         %d\n", stackSize);
        printf("stack+size address: %x\n", (char *)(stackBase) + stackSize);
        p = (char *)(stackBase) + stackSize - 1;
        printf("lets read the top:  %x\n", *p);
 
        return 0;
}

--
Adam

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