From d19ad0775dcd64b49eecf4fa79c17959ebfbd26b Mon Sep 17 00:00:00 2001
From: "Steven Rostedt (VMware)" <rostedt@goodmis.org>
Date: Wed, 28 Oct 2020 17:42:17 -0400
Subject: ftrace: Have the callbacks receive a struct ftrace_regs instead of
pt_regs
In preparation to have arguments of a function passed to callbacks attached
to functions as default, change the default callback prototype to receive a
struct ftrace_regs as the forth parameter instead of a pt_regs.
For callbacks that set the FL_SAVE_REGS flag in their ftrace_ops flags, they
will now need to get the pt_regs via a ftrace_get_regs() helper call. If
this is called by a callback that their ftrace_ops did not have a
FL_SAVE_REGS flag set, it that helper function will return NULL.
This will allow the ftrace_regs to hold enough just to get the parameters
and stack pointer, but without the worry that callbacks may have a pt_regs
that is not completely filled.
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
---
kernel/livepatch/patch.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
(limited to 'kernel/livepatch/patch.c')
diff --git a/kernel/livepatch/patch.c b/kernel/livepatch/patch.c
index 875c5dbbdd33..f89f9e7e9b07 100644
--- a/kernel/livepatch/patch.c
+++ b/kernel/livepatch/patch.c
@@ -40,8 +40,9 @@ struct klp_ops *klp_find_ops(void *old_func)
static void notrace klp_ftrace_handler(unsigned long ip,
unsigned long parent_ip,
struct ftrace_ops *fops,
- struct pt_regs *regs)
+ struct ftrace_regs *fregs)
{
+ struct pt_regs *regs = ftrace_get_regs(fregs);
struct klp_ops *ops;
struct klp_func *func;
int patch_state;
--
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