powerpc: Check end of stack canary at oops time

Add a check for the stack canary when we oops, similar to x86. This should make
it clear that we overran our stack:

Unable to handle kernel paging request for data at address 0x24652f63700ac689
Faulting instruction address: 0xc000000000063d24
Thread overran stack, or stack corrupted

Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
This commit is contained in:
Anton Blanchard 2010-08-24 13:15:28 +00:00 committed by Benjamin Herrenschmidt
parent f89451fbd2
commit 28b549905b

View file

@ -30,6 +30,7 @@
#include <linux/kprobes.h>
#include <linux/kdebug.h>
#include <linux/perf_event.h>
#include <linux/magic.h>
#include <asm/firmware.h>
#include <asm/page.h>
@ -385,6 +386,7 @@ do_sigbus:
void bad_page_fault(struct pt_regs *regs, unsigned long address, int sig)
{
const struct exception_table_entry *entry;
unsigned long *stackend;
/* Are we prepared to handle this fault? */
if ((entry = search_exception_tables(regs->nip)) != NULL) {
@ -413,5 +415,9 @@ void bad_page_fault(struct pt_regs *regs, unsigned long address, int sig)
printk(KERN_ALERT "Faulting instruction address: 0x%08lx\n",
regs->nip);
stackend = end_of_stack(current);
if (current != &init_task && *stackend != STACK_END_MAGIC)
printk(KERN_ALERT "Thread overran stack, or stack corrupted\n");
die("Kernel access of bad area", regs, sig);
}