From 28b549905b239357db7c249e261857c1716db05a Mon Sep 17 00:00:00 2001 From: Anton Blanchard Date: Tue, 24 Aug 2010 13:15:28 +0000 Subject: [PATCH] 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 Signed-off-by: Benjamin Herrenschmidt --- arch/powerpc/mm/fault.c | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/arch/powerpc/mm/fault.c b/arch/powerpc/mm/fault.c index 1bd712c..54f4fb9 100644 --- a/arch/powerpc/mm/fault.c +++ b/arch/powerpc/mm/fault.c @@ -30,6 +30,7 @@ #include #include #include +#include #include #include @@ -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); } -- 2.7.4