diff options
Diffstat (limited to 'arch/riscv/kernel/ftrace.c')
-rw-r--r-- | arch/riscv/kernel/ftrace.c | 41 |
1 files changed, 41 insertions, 0 deletions
diff --git a/arch/riscv/kernel/ftrace.c b/arch/riscv/kernel/ftrace.c new file mode 100644 index 0000000..d0de68d --- /dev/null +++ b/arch/riscv/kernel/ftrace.c @@ -0,0 +1,41 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +/* + * Copyright (C) 2013 Linaro Limited + * Author: AKASHI Takahiro <takahiro.akashi@linaro.org> + * Copyright (C) 2017 Andes Technology Corporation + */ + +#include <linux/ftrace.h> + +/* + * Most of this file is copied from arm64. + */ +void prepare_ftrace_return(unsigned long *parent, unsigned long self_addr, + unsigned long frame_pointer) +{ + unsigned long return_hooker = (unsigned long)&return_to_handler; + unsigned long old; + struct ftrace_graph_ent trace; + int err; + + if (unlikely(atomic_read(¤t->tracing_graph_pause))) + return; + + /* + * We don't suffer access faults, so no extra fault-recovery assembly + * is needed here. + */ + old = *parent; + + trace.func = self_addr; + trace.depth = current->curr_ret_stack + 1; + + if (!ftrace_graph_entry(&trace)) + return; + + err = ftrace_push_return_trace(old, self_addr, &trace.depth, + frame_pointer, NULL); + if (err == -EBUSY) + return; + *parent = return_hooker; +} |