[PATCH] unwinder: more sanity checks in Dwarf2 unwinder
Tighten the requirements on both input to and output from the Dwarf2
unwinder.
Signed-off-by: Jan Beulich <jbeulich@novell.com>
Signed-off-by: Andi Kleen <ak@suse.de>
diff --git a/arch/i386/kernel/traps.c b/arch/i386/kernel/traps.c
index 86d8476..c447807 100644
--- a/arch/i386/kernel/traps.c
+++ b/arch/i386/kernel/traps.c
@@ -161,12 +161,19 @@
{
struct ops_and_data *oad = (struct ops_and_data *)data;
int n = 0;
+ unsigned long sp = UNW_SP(info);
+ if (arch_unw_user_mode(info))
+ return -1;
while (unwind(info) == 0 && UNW_PC(info)) {
n++;
oad->ops->address(oad->data, UNW_PC(info));
if (arch_unw_user_mode(info))
break;
+ if ((sp & ~(PAGE_SIZE - 1)) == (UNW_SP(info) & ~(PAGE_SIZE - 1))
+ && sp > UNW_SP(info))
+ break;
+ sp = UNW_SP(info);
}
return n;
}