[for-next][PATCH 07/24] sh: ftrace: Use ftrace_graph_get_ret_stack() instead of curr_ret_stack

Steven Rostedt
2018-12-21T17:58:39Z

From: "Steven Rostedt (VMware)" <rostedt@goodmis.org>

The structure of the ret_stack array on the task struct is going to
change, and accessing it directly via the curr_ret_stack index will no
longer give the ret_stack entry that holds the return address. To access
that, architectures must now use ftrace_graph_get_ret_stack() to get the
associated ret_stack that matches the saved return address.

Cc: linux-sh@vger.kernel.org
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Cc: Rich Felker <dalias@libc.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
---
arch/sh/kernel/dumpstack.c | 11 +++++++----
arch/sh/kernel/dwarf.c | 9 +++++----
2 files changed, 12 insertions(+), 8 deletions(-)

diff --git a/arch/sh/kernel/dumpstack.c b/arch/sh/kernel/dumpstack.c
index b564b1eae4ae..2c2e151bf39e 100644
--- a/arch/sh/kernel/dumpstack.c
+++ b/arch/sh/kernel/dumpstack.c
@@ -59,17 +59,20 @@ print_ftrace_graph_addr(unsigned long addr, void *data,
struct thread_info *tinfo, int *graph)
{
struct task_struct *task = tinfo->task;
+ struct ftrace_ret_stack *ret_stack;
unsigned long ret_addr;
- int index = task->curr_ret_stack;

if (addr != (unsigned long)return_to_handler)
return;

- if (!task->ret_stack || index < *graph)
+ if (!task->ret_stack)
return;

- index -= *graph;
- ret_addr = task->ret_stack[index].ret;
+ ret_stack = ftrace_graph_get_ret_stack(task, *graph);
+ if (!ret_stack)
+ return;
+
+ ret_addr = ret_stack->ret;

ops->address(data, ret_addr, 1);

diff --git a/arch/sh/kernel/dwarf.c b/arch/sh/kernel/dwarf.c
index bb511e2d9d68..df0fd6efe758 100644
--- a/arch/sh/kernel/dwarf.c
+++ b/arch/sh/kernel/dwarf.c
@@ -608,17 +608,18 @@ struct dwarf_frame *dwarf_unwind_stack(unsigned long pc,
* expected to find the real return address.
*/
if (pc == (unsigned long)&return_to_handler) {
- int index = current->curr_ret_stack;
+ struct ftrace_ret_stack *ret_stack;

+ ret_stack = ftrace_graph_get_ret_stack(current, 0);
+ if (ret_stack)
+ pc = ret_stack->ret;
/*
* We currently have no way of tracking how many
* return_to_handler()'s we've seen. If there is more
* than one patched return address on our stack,
* complain loudly.
*/
- WARN_ON(index > 0);
-
- pc = current->ret_stack[index].ret;
+ WARN_ON(ftrace_graph_get_ret_stack(current, 1);
}
#endif

--
2.19.2