x86/dumpstack/ftrace: Convert dump_trace() callbacks to use ftrace_graph_ret_addr()

Convert print_context_stack() and print_context_stack_bp() to use the
arch-independent ftrace_graph_ret_addr() helper.

Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
Acked-by: Steven Rostedt <rostedt@goodmis.org>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Byungchul Park <byungchul.park@lge.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Nilay Vaish <nilayvaish@gmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/56ec97cafc1bf2e34d1119e6443d897db406da86.1471607358.git.jpoimboe@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>

diff --git a/arch/x86/kernel/dumpstack.c b/arch/x86/kernel/dumpstack.c
index 5f49c04..9bf3d02 100644 (file)
--- a/arch/x86/kernel/dumpstack.c
+++ b/arch/x86/kernel/dumpstack.c
@@ -38,38 +38,6 @@ void printk_address(unsigned long address)
        pr_cont(" [<%p>] %pS\n", (void *)address, (void *)address);
 }
 
-#ifdef CONFIG_FUNCTION_GRAPH_TRACER
-static void
-print_ftrace_graph_addr(unsigned long addr, void *data,
-                       const struct stacktrace_ops *ops,
-                       struct task_struct *task, int *graph)
-{
-       unsigned long ret_addr;
-       int index;
-
-       if (addr != (unsigned long)return_to_handler)
-               return;
-
-       index = task->curr_ret_stack;
-
-       if (!task->ret_stack || index < *graph)
-               return;
-
-       index -= *graph;
-       ret_addr = task->ret_stack[index].ret;
-
-       ops->address(data, ret_addr, 1);
-
-       (*graph)++;
-}
-#else
-static inline void
-print_ftrace_graph_addr(unsigned long addr, void *data,
-                       const struct stacktrace_ops *ops,
-                       struct task_struct *task, int *graph)
-{ }
-#endif
-
 /*
  * x86-64 can have up to three kernel stacks:
  * process stack
@@ -107,18 +75,24 @@ print_context_stack(struct task_struct *task,
                stack = (unsigned long *)task_stack_page(task);
 
        while (valid_stack_ptr(task, stack, sizeof(*stack), end)) {
-               unsigned long addr;
+               unsigned long addr = *stack;
 
-               addr = *stack;
                if (__kernel_text_address(addr)) {
+                       unsigned long real_addr;
+                       int reliable = 0;
+
                        if ((unsigned long) stack == bp + sizeof(long)) {
-                               ops->address(data, addr, 1);
+                               reliable = 1;
                                frame = frame->next_frame;
                                bp = (unsigned long) frame;
-                       } else {
-                               ops->address(data, addr, 0);
                        }
-                       print_ftrace_graph_addr(addr, data, ops, task, graph);
+
+                       ops->address(data, addr, reliable);
+
+                       real_addr = ftrace_graph_ret_addr(task, graph, addr,
+                                                         stack);
+                       if (real_addr != addr)
+                               ops->address(data, real_addr, 1);
                }
                stack++;
        }
@@ -133,19 +107,24 @@ print_context_stack_bp(struct task_struct *task,
                       unsigned long *end, int *graph)
 {
        struct stack_frame *frame = (struct stack_frame *)bp;
-       unsigned long *ret_addr = &frame->return_address;
+       unsigned long *retp = &frame->return_address;
 
-       while (valid_stack_ptr(task, ret_addr, sizeof(*ret_addr), end)) {
-               unsigned long addr = *ret_addr;
+       while (valid_stack_ptr(task, retp, sizeof(*retp), end)) {
+               unsigned long addr = *retp;
+               unsigned long real_addr;
 
                if (!__kernel_text_address(addr))
                        break;
 
                if (ops->address(data, addr, 1))
                        break;
+
+               real_addr = ftrace_graph_ret_addr(task, graph, addr, retp);
+               if (real_addr != addr)
+                       ops->address(data, real_addr, 1);
+
                frame = frame->next_frame;
-               ret_addr = &frame->return_address;
-               print_ftrace_graph_addr(addr, data, ops, task, graph);
+               retp = &frame->return_address;
        }
 
        return (unsigned long)frame;