---

yaml
---
r: 257088
b: refs/heads/master
c: a2bbe75
h: refs/heads/master
v: v3

[refs]

@@ -1,2 +1,2 @@
 ---
-refs/heads/master: 48ffee7d9e6df51b4957bed64115b7beed671374
+refs/heads/master: a2bbe75089d5eb9a3a46d50dd5c215e213790288

trunk/arch/x86/kernel/dumpstack_64.c

@@ -104,34 +104,6 @@ in_irq_stack(unsigned long *stack, unsigned long *irq_stack,
 	return (stack >= irq_stack && stack < irq_stack_end);
 }
 
-/*
- * We are returning from the irq stack and go to the previous one.
- * If the previous stack is also in the irq stack, then bp in the first
- * frame of the irq stack points to the previous, interrupted one.
- * Otherwise we have another level of indirection: We first save
- * the bp of the previous stack, then we switch the stack to the irq one
- * and save a new bp that links to the previous one.
- * (See save_args())
- */
-static inline unsigned long
-fixup_bp_irq_link(unsigned long bp, unsigned long *stack,
-		  unsigned long *irq_stack, unsigned long *irq_stack_end)
-{
-#ifdef CONFIG_FRAME_POINTER
-	struct stack_frame *frame = (struct stack_frame *)bp;
-	unsigned long next;
-
-	if (!in_irq_stack(stack, irq_stack, irq_stack_end)) {
-		if (!probe_kernel_address(&frame->next_frame, next))
-			return next;
-		else
-			WARN_ONCE(1, "Perf: bad frame pointer = %p in "
-				  "callchain\n", &frame->next_frame);
-	}
-#endif
-	return bp;
-}
-
 /*
  * x86-64 can have up to three kernel stacks:
  * process stack
@@ -208,8 +180,6 @@ void dump_trace(struct task_struct *task, struct pt_regs *regs,
 				 * pointer (index -1 to end) in the IRQ stack:
 				 */
 				stack = (unsigned long *) (irq_stack_end[-1]);
-				bp = fixup_bp_irq_link(bp, stack, irq_stack,
-						       irq_stack_end);
 				irq_stack_end = NULL;
 				ops->stack(data, "EOI");
 				continue;

trunk/arch/x86/kernel/entry_64.S

@@ -310,8 +310,11 @@ ENDPROC(native_usergs_sysret64)
 	movq_cfi r10, R10-RBP
 	movq_cfi r11, R11-RBP
 
-	movq_cfi rbp, 0		/* push %rbp */
-	movq %rsp, %rbp
+	/* Save rbp so that we can unwind from get_irq_regs() */
+	movq_cfi rbp, 0
+
+	/* Save previous stack value */
+	movq %rsp, %rsi
 
 	leaq -RBP(%rsp),%rdi	/* arg1 for handler */
 	testl $3, CS(%rdi)
@@ -327,10 +330,11 @@ ENDPROC(native_usergs_sysret64)
 	jne 2f
 	mov PER_CPU_VAR(irq_stack_ptr),%rsp
 	EMPTY_FRAME 0
-	/*
-	 * We entered an interrupt context - irqs are off:
-	 */
-2:	TRACE_IRQS_OFF
+
+2:	/* Store previous stack value */
+	pushq %rsi
+	/* We entered an interrupt context - irqs are off: */
+	TRACE_IRQS_OFF
 	.endm
 
 ENTRY(save_rest)
@@ -804,15 +808,14 @@ ret_from_intr:
 	DISABLE_INTERRUPTS(CLBR_NONE)
 	TRACE_IRQS_OFF
 	decl PER_CPU_VAR(irq_count)
-	leaveq
 
-	CFI_RESTORE		rbp
+	/* Restore saved previous stack */
+	popq %rsi
+	leaq 16(%rsi), %rsp
+
 	CFI_DEF_CFA_REGISTER	rsp
-	CFI_ADJUST_CFA_OFFSET	-8
+	CFI_ADJUST_CFA_OFFSET	-16
 
-	/* we did not save rbx, restore only from ARGOFFSET */
-	addq $8, %rsp
-	CFI_ADJUST_CFA_OFFSET	-8
 exit_intr:
 	GET_THREAD_INFO(%rcx)
 	testl $3,CS-ARGOFFSET(%rsp)