dumpstack: x86: add "end" parameter to valid_stack_ptr and print_context_stack

- Add "end" parameter to valid_stack_ptr and print_context_stack
 - use sizeof(long) as the size of a word on the stack

Signed-off-by: Alexander van Heukelum <heukelum@fastmail.fm>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

1 files changed, 13 insertions, 6 deletions

diff --git a/arch/x86/kernel/dumpstack_32.c b/arch/x86/kernel/dumpstack_32.c
index 4e67a005c7a1..466d55dfeb87 100644
--- a/arch/x86/kernel/dumpstack_32.c
+++ b/arch/x86/kernel/dumpstack_32.c
@@ -28,10 +28,16 @@ void printk_address(unsigned long address, int reliable)
 }
 
 static inline int valid_stack_ptr(struct thread_info *tinfo,
-                        void *p, unsigned int size)
+                        void *p, unsigned int size, void *end)
 {
         void *t = tinfo;
-        return  p > t && p <= t + THREAD_SIZE - size;
+        if (end) {
+                if (p < end && p >= (end-THREAD_SIZE))
+                        return 1;
+                else
+                        return 0;
+        }
+        return p > t && p < t + THREAD_SIZE - size;
 }
 
 /* The form of the top of the frame on the stack */
@@ -43,16 +49,17 @@ struct stack_frame {
 static inline unsigned long
 print_context_stack(struct thread_info *tinfo,
                 unsigned long *stack, unsigned long bp,
-                const struct stacktrace_ops *ops, void *data)
+                const struct stacktrace_ops *ops, void *data,
+                unsigned long *end)
 {
         struct stack_frame *frame = (struct stack_frame *)bp;
 
-        while (valid_stack_ptr(tinfo, stack, sizeof(*stack))) {
+        while (valid_stack_ptr(tinfo, stack, sizeof(*stack), end)) {
                 unsigned long addr;
 
                 addr = *stack;
                 if (__kernel_text_address(addr)) {
-                        if ((unsigned long) stack == bp + 4) {
+                        if ((unsigned long) stack == bp + sizeof(long)) {
                                 ops->address(data, addr, 1);
                                 frame = frame->next_frame;
                                 bp = (unsigned long) frame;
@@ -96,7 +103,7 @@ void dump_trace(struct task_struct *task, struct pt_regs *regs,
 
                 context = (struct thread_info *)
                         ((unsigned long)stack & (~(THREAD_SIZE - 1)));
-                bp = print_context_stack(context, stack, bp, ops, data);
+                bp = print_context_stack(context, stack, bp, ops, data, NULL);
                 /*
                  * Should be after the line below, but somewhere
                  * in early boot context comes out corrupted and we