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Message-Id: <20180115064742.25324-7-alankao@andestech.com>
Date: Mon, 15 Jan 2018 14:47:42 +0800
From: Alan Kao <nonerkao@...il.com>
To: Palmer Dabbelt <palmer@...ive.com>, Albert Ou <albert@...ive.com>,
Christoph Hellwig <hch@....de>,
Steven Rostedt <rostedt@...dmis.org>,
Ingo Molnar <mingo@...hat.com>,
Masahiro Yamada <yamada.masahiro@...ionext.com>,
Kamil Rytarowski <n54@....com>,
Andrew Morton <akpm@...ux-foundation.org>,
patches@...ups.riscv.org, linux-kernel@...r.kernel.org
Cc: Alan Kao <alankao@...estech.com>,
Greentime Hu <greentime@...estech.com>
Subject: [PATCH v2 6/6] riscv/ftrace: Add HAVE_FUNCTION_GRAPH_RET_ADDR_PTR support
In walk_stackframe, the pc now receives the address from calling
ftrace_graph_ret_addr instead of manual calculation.
Note that the original calculation,
pc = frame->ra - 4
is buggy when the instruction at the return address happened to be a
compressed inst. But since it is not a critical part of ftrace, it is
ignored for now to ease the review process.
Cc: Greentime Hu <greentime@...estech.com>
Signed-off-by: Alan Kao <alankao@...estech.com>
---
arch/riscv/include/asm/ftrace.h | 1 +
arch/riscv/kernel/ftrace.c | 2 +-
arch/riscv/kernel/stacktrace.c | 6 ++++++
3 files changed, 8 insertions(+), 1 deletion(-)
diff --git a/arch/riscv/include/asm/ftrace.h b/arch/riscv/include/asm/ftrace.h
index 429a6a156645..6e4b4c96b63e 100644
--- a/arch/riscv/include/asm/ftrace.h
+++ b/arch/riscv/include/asm/ftrace.h
@@ -8,6 +8,7 @@
#if defined(CONFIG_FUNCTION_GRAPH_TRACER) && defined(CONFIG_FRAME_POINTER)
#define HAVE_FUNCTION_GRAPH_FP_TEST
#endif
+#define HAVE_FUNCTION_GRAPH_RET_ADDR_PTR
#define ARCH_SUPPORTS_FTRACE_OPS 1
#ifndef __ASSEMBLY__
diff --git a/arch/riscv/kernel/ftrace.c b/arch/riscv/kernel/ftrace.c
index 3922b29c107b..ded8ab25f4ad 100644
--- a/arch/riscv/kernel/ftrace.c
+++ b/arch/riscv/kernel/ftrace.c
@@ -150,7 +150,7 @@ void prepare_ftrace_return(unsigned long *parent, unsigned long self_addr,
return;
err = ftrace_push_return_trace(old, self_addr, &trace.depth,
- frame_pointer, NULL);
+ frame_pointer, parent);
if (err == -EBUSY)
return;
*parent = return_hooker;
diff --git a/arch/riscv/kernel/stacktrace.c b/arch/riscv/kernel/stacktrace.c
index 559aae781154..a4b1d94371a0 100644
--- a/arch/riscv/kernel/stacktrace.c
+++ b/arch/riscv/kernel/stacktrace.c
@@ -18,6 +18,7 @@
#include <linux/sched/debug.h>
#include <linux/sched/task_stack.h>
#include <linux/stacktrace.h>
+#include <linux/ftrace.h>
#ifdef CONFIG_FRAME_POINTER
@@ -63,7 +64,12 @@ static void notrace walk_stackframe(struct task_struct *task,
frame = (struct stackframe *)fp - 1;
sp = fp;
fp = frame->fp;
+#ifdef HAVE_FUNCTION_GRAPH_RET_ADDR_PTR
+ pc = ftrace_graph_ret_addr(current, NULL, frame->ra,
+ (unsigned long *)(fp - 8));
+#else
pc = frame->ra - 0x4;
+#endif
}
}
--
2.15.1
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