Messages in this thread | | | Date | Tue, 15 Dec 1998 01:44:23 +0100 (CET) | From | Andrea Arcangeli <> | Subject | Re: [PATCH] i386 get_wchan() bugs (fs/proc/array.c) |
| |
On Thu, 10 Dec 1998, Jamie Lokier wrote:
>+ /* ebp isn't valid for newly created threads, but eip is. */ >+ eip = p->tss.eip; >+ if (eip < first_sched || eip >= last_sched) >+ return eip;
Right.
> stack_page = (unsigned long)p; > esp = p->tss.esp; >- if (!stack_page || esp < stack_page || esp >= 8188+stack_page) >+ if (!stack_page || esp < stack_page || esp > 8188+stack_page)
Wrong. Dereferencing esp will not fault if it will be equal to 8188+stack_page.
> return 0; > /* include/asm-i386/system.h:switch_to() pushes ebp last. */ > ebp = *(unsigned long *) esp; > do { >- if (ebp < stack_page || ebp >= 8188+stack_page) >+ if (ebp < stack_page || ebp > 8184+stack_page)
Also here the check can be `ebp >= 8184+stack_page'.
Tell me if it' s too late to thing to these issues ;)
Andrea Arcangeli
- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.rutgers.edu Please read the FAQ at http://www.tux.org/lkml/
| |