From b785ec129bd9498ecd6e221e45820b00c6ed4adf Mon Sep 17 00:00:00 2001 From: Alan Kao Date: Tue, 13 Feb 2018 13:13:21 +0800 Subject: [PATCH] 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 Signed-off-by: Alan Kao Signed-off-by: Palmer Dabbelt --- arch/riscv/kernel/ftrace.c | 2 +- arch/riscv/kernel/stacktrace.c | 6 ++++++ 2 files changed, 7 insertions(+), 1 deletion(-) diff --git a/arch/riscv/kernel/ftrace.c b/arch/riscv/kernel/ftrace.c index 48b5353..1157b6b 100644 --- a/arch/riscv/kernel/ftrace.c +++ b/arch/riscv/kernel/ftrace.c @@ -151,7 +151,7 @@ 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 559aae7..a4b1d94 100644 --- a/arch/riscv/kernel/stacktrace.c +++ b/arch/riscv/kernel/stacktrace.c @@ -18,6 +18,7 @@ #include #include #include +#include #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 } } -- 2.7.4