Blackfin arch: Add one more check on `fp' to prevent double fault

Signed-off-by: Jie Zhang <jie.zhang@analog.com>
Signed-off-by: Bryan Wu <cooloney@kernel.org>

diff --git a/arch/blackfin/kernel/traps.c b/arch/blackfin/kernel/traps.c
index f18c248..7992641 100644 (file)
--- a/arch/blackfin/kernel/traps.c
+++ b/arch/blackfin/kernel/traps.c
@@ -820,11 +820,8 @@ void show_stack(struct task_struct *task, unsigned long *stack)
        decode_address(buf, (unsigned int)stack);
        printk(KERN_NOTICE " SP: [0x%p] %s\n", stack, buf);
 
-       addr = (unsigned int *)((unsigned int)stack & ~0x3F);
-
        /* First thing is to look for a frame pointer */
-       for (addr = (unsigned int *)((unsigned int)stack & ~0xF), i = 0;
-               addr < endstack; addr++, i++) {
+       for (addr = (unsigned int *)((unsigned int)stack & ~0xF); addr < endstack; addr++) {
                if (*addr & 0x1)
                        continue;
                ins_addr = (unsigned short *)*addr;
@@ -834,7 +831,8 @@ void show_stack(struct task_struct *task, unsigned long *stack)
 
                if (fp) {
                        /* Let's check to see if it is a frame pointer */
-                       while (fp >= (addr - 1) && fp < endstack && fp)
+                       while (fp >= (addr - 1) && fp < endstack
+                              && fp && ((unsigned int) fp & 0x3) == 0)
                                fp = (unsigned int *)*fp;
                        if (fp == 0 || fp == endstack) {
                                fp = addr - 1;