5 files changed, 89 insertions, 3 deletions

diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index 0842b1127684..45c86fb94132 100644
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -29,7 +29,7 @@ config X86
         select HAVE_FTRACE_MCOUNT_RECORD
         select HAVE_DYNAMIC_FTRACE
         select HAVE_FUNCTION_TRACER
-        select HAVE_FUNCTION_GRAPH_TRACER if X86_32
+        select HAVE_FUNCTION_GRAPH_TRACER
         select HAVE_FUNCTION_TRACE_MCOUNT_TEST
         select HAVE_KVM if ((X86_32 && !X86_VOYAGER && !X86_VISWS && !X86_NUMAQ) || X86_64)
         select HAVE_ARCH_KGDB if !X86_VOYAGER
diff --git a/arch/x86/kernel/Makefile b/arch/x86/kernel/Makefile
index 64939a0c3986..d274425fb076 100644
--- a/arch/x86/kernel/Makefile
+++ b/arch/x86/kernel/Makefile
@@ -17,6 +17,7 @@ endif
 ifdef CONFIG_FUNCTION_GRAPH_TRACER
 # Don't trace __switch_to() but let it for function tracer
 CFLAGS_REMOVE_process_32.o = -pg
+CFLAGS_REMOVE_process_64.o = -pg
 endif
 
 #
diff --git a/arch/x86/kernel/entry_64.S b/arch/x86/kernel/entry_64.S
index 08aa6b10933c..2aa0526ac30e 100644
--- a/arch/x86/kernel/entry_64.S
+++ b/arch/x86/kernel/entry_64.S
@@ -98,6 +98,12 @@ ftrace_call:
         movq (%rsp), %rax
         addq $0x38, %rsp
 
+#ifdef CONFIG_FUNCTION_GRAPH_TRACER
+.globl ftrace_graph_call
+ftrace_graph_call:
+        jmp ftrace_stub
+#endif
+
 .globl ftrace_stub
 ftrace_stub:
         retq
@@ -110,6 +116,12 @@ ENTRY(mcount)
 
         cmpq $ftrace_stub, ftrace_trace_function
         jnz trace
+
+#ifdef CONFIG_FUNCTION_GRAPH_TRACER
+        cmpq $ftrace_stub, ftrace_graph_return
+        jnz ftrace_graph_caller
+#endif
+
 .globl ftrace_stub
 ftrace_stub:
         retq
@@ -145,6 +157,68 @@ END(mcount)
 #endif /* CONFIG_DYNAMIC_FTRACE */
 #endif /* CONFIG_FUNCTION_TRACER */
 
+#ifdef CONFIG_FUNCTION_GRAPH_TRACER
+ENTRY(ftrace_graph_caller)
+        cmpl $0, function_trace_stop
+        jne ftrace_stub
+
+        subq $0x38, %rsp
+        movq %rax, (%rsp)
+        movq %rcx, 8(%rsp)
+        movq %rdx, 16(%rsp)
+        movq %rsi, 24(%rsp)
+        movq %rdi, 32(%rsp)
+        movq %r8, 40(%rsp)
+        movq %r9, 48(%rsp)
+
+        leaq 8(%rbp), %rdi
+        movq 0x38(%rsp), %rsi
+
+        call    prepare_ftrace_return
+
+        movq 48(%rsp), %r9
+        movq 40(%rsp), %r8
+        movq 32(%rsp), %rdi
+        movq 24(%rsp), %rsi
+        movq 16(%rsp), %rdx
+        movq 8(%rsp), %rcx
+        movq (%rsp), %rax
+        addq $0x38, %rsp
+        retq
+END(ftrace_graph_caller)
+
+
+.globl return_to_handler
+return_to_handler:
+        subq  $80, %rsp
+
+        movq %rax, (%rsp)
+        movq %rcx, 8(%rsp)
+        movq %rdx, 16(%rsp)
+        movq %rsi, 24(%rsp)
+        movq %rdi, 32(%rsp)
+        movq %r8, 40(%rsp)
+        movq %r9, 48(%rsp)
+        movq %r10, 56(%rsp)
+        movq %r11, 64(%rsp)
+
+        call ftrace_return_to_handler
+
+        movq %rax, 72(%rsp)
+        movq 64(%rsp), %r11
+        movq 56(%rsp), %r10
+        movq 48(%rsp), %r9
+        movq 40(%rsp), %r8
+        movq 32(%rsp), %rdi
+        movq 24(%rsp), %rsi
+        movq 16(%rsp), %rdx
+        movq 8(%rsp), %rcx
+        movq (%rsp), %rax
+        addq $72, %rsp
+        retq
+#endif
+
+
 #ifndef CONFIG_PREEMPT
 #define retint_kernel retint_restore_args
 #endif  
diff --git a/arch/x86/kernel/ftrace.c b/arch/x86/kernel/ftrace.c
index 7ef914e6a2f6..58832478b94e 100644
--- a/arch/x86/kernel/ftrace.c
+++ b/arch/x86/kernel/ftrace.c
@@ -467,8 +467,13 @@ void prepare_ftrace_return(unsigned long *parent, unsigned long self_addr)
          * ignore such a protection.
          */
         asm volatile(
+#ifdef CONFIG_X86_64
+                "1: movq (%[parent_old]), %[old]\n"
+                "2: movq %[return_hooker], (%[parent_replaced])\n"
+#else
                 "1: movl (%[parent_old]), %[old]\n"
                 "2: movl %[return_hooker], (%[parent_replaced])\n"
+#endif
                 "   movl $0, %[faulted]\n"
 
                 ".section .fixup, \"ax\"\n"
@@ -476,8 +481,13 @@ void prepare_ftrace_return(unsigned long *parent, unsigned long self_addr)
                 ".previous\n"
 
                 ".section __ex_table, \"a\"\n"
+#ifdef CONFIG_X86_64
+                "   .quad 1b, 3b\n"
+                "   .quad 2b, 3b\n"
+#else
                 "   .long 1b, 3b\n"
                 "   .long 2b, 3b\n"
+#endif
                 ".previous\n"
 
                 : [parent_replaced] "=r" (parent), [old] "=r" (old),
@@ -509,5 +519,4 @@ void prepare_ftrace_return(unsigned long *parent, unsigned long self_addr)
         ftrace_graph_entry(&trace);
 
 }
-
 #endif /* CONFIG_FUNCTION_GRAPH_TRACER */
diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c
index 08b536a2614e..f72499627525 100644
--- a/kernel/trace/ftrace.c
+++ b/kernel/trace/ftrace.c
@@ -1673,8 +1673,10 @@ static int alloc_retstack_tasklist(struct ftrace_ret_stack **ret_stack_list)
                 }
 
                 if (t->ret_stack == NULL) {
-                        t->ret_stack = ret_stack_list[start++];
                         t->curr_ret_stack = -1;
+                        /* Make sure IRQs see the -1 first: */
+                        barrier();
+                        t->ret_stack = ret_stack_list[start++];
                         atomic_set(&t->trace_overrun, 0);
                 }
         } while_each_thread(g, t);