Merge branch 'perf/stacktrace' of git://git.kernel.org/pub/scm/linux/kernel/git/frede...

diff --git a/arch/x86/include/asm/perf_event.h b/arch/x86/include/asm/perf_event.h
index d9d4dae..094fb30 100644 (file)
--- a/arch/x86/include/asm/perf_event.h
+++ b/arch/x86/include/asm/perf_event.h
@@ -152,6 +152,11 @@ extern unsigned long perf_misc_flags(struct pt_regs *regs);
        (regs)->bp = caller_frame_pointer();                    \
        (regs)->cs = __KERNEL_CS;                               \
        regs->flags = 0;                                        \
+       asm volatile(                                           \
+               _ASM_MOV "%%"_ASM_SP ", %0\n"                   \
+               : "=m" ((regs)->sp)                             \
+               :: "memory"                                     \
+       );                                                      \
 }
 
 #else

diff --git a/arch/x86/kernel/dumpstack_64.c b/arch/x86/kernel/dumpstack_64.c
index e71c98d..19853ad 100644 (file)
--- a/arch/x86/kernel/dumpstack_64.c
+++ b/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
@@ -155,9 +127,12 @@ void dump_trace(struct task_struct *task, struct pt_regs *regs,
                task = current;
 
        if (!stack) {
-               stack = &dummy;
-               if (task && task != current)
+               if (regs)
+                       stack = (unsigned long *)regs->sp;
+               else if (task && task != current)
                        stack = (unsigned long *)task->thread.sp;
+               else
+                       stack = &dummy;
        }
 
        if (!bp)
@@ -205,8 +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;

diff --git a/arch/x86/kernel/entry_64.S b/arch/x86/kernel/entry_64.S
index 8a445a0..d656f68 100644 (file)
--- a/arch/x86/kernel/entry_64.S
+++ b/arch/x86/kernel/entry_64.S
@@ -297,27 +297,26 @@ ENDPROC(native_usergs_sysret64)
        .endm
 
 /* save partial stack frame */
-       .pushsection .kprobes.text, "ax"
-ENTRY(save_args)
-       XCPT_FRAME
+       .macro SAVE_ARGS_IRQ
        cld
-       /*
-        * start from rbp in pt_regs and jump over
-        * return address.
-        */
-       movq_cfi rdi, RDI+8-RBP
-       movq_cfi rsi, RSI+8-RBP
-       movq_cfi rdx, RDX+8-RBP
-       movq_cfi rcx, RCX+8-RBP
-       movq_cfi rax, RAX+8-RBP
-       movq_cfi  r8,  R8+8-RBP
-       movq_cfi  r9,  R9+8-RBP
-       movq_cfi r10, R10+8-RBP
-       movq_cfi r11, R11+8-RBP
-
-       leaq -RBP+8(%rsp),%rdi  /* arg1 for handler */
-       movq_cfi rbp, 8         /* push %rbp */
-       leaq 8(%rsp), %rbp              /* mov %rsp, %ebp */
+       /* start from rbp in pt_regs and jump over */
+       movq_cfi rdi, RDI-RBP
+       movq_cfi rsi, RSI-RBP
+       movq_cfi rdx, RDX-RBP
+       movq_cfi rcx, RCX-RBP
+       movq_cfi rax, RAX-RBP
+       movq_cfi  r8,  R8-RBP
+       movq_cfi  r9,  R9-RBP
+       movq_cfi r10, R10-RBP
+       movq_cfi r11, R11-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)
        je 1f
        SWAPGS
@@ -329,19 +328,14 @@ ENTRY(save_args)
         */
 1:     incl PER_CPU_VAR(irq_count)
        jne 2f
-       popq_cfi %rax                   /* move return address... */
        mov PER_CPU_VAR(irq_stack_ptr),%rsp
        EMPTY_FRAME 0
-       pushq_cfi %rbp                  /* backlink for unwinder */
-       pushq_cfi %rax                  /* ... to the new stack */
-       /*
-        * We entered an interrupt context - irqs are off:
-        */
-2:     TRACE_IRQS_OFF
-       ret
-       CFI_ENDPROC
-END(save_args)
-       .popsection
+
+2:     /* Store previous stack value */
+       pushq %rsi
+       /* We entered an interrupt context - irqs are off: */
+       TRACE_IRQS_OFF
+       .endm
 
 ENTRY(save_rest)
        PARTIAL_FRAME 1 REST_SKIP+8
@@ -791,7 +785,7 @@ END(interrupt)
        /* reserve pt_regs for scratch regs and rbp */
        subq $ORIG_RAX-RBP, %rsp
        CFI_ADJUST_CFA_OFFSET ORIG_RAX-RBP
-       call save_args
+       SAVE_ARGS_IRQ
        PARTIAL_FRAME 0
        call \func
        .endm
@@ -814,15 +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)