diff options
Diffstat (limited to 'arch/csky/kernel/ftrace.c')
| -rw-r--r-- | arch/csky/kernel/ftrace.c | 48 |
1 files changed, 37 insertions, 11 deletions
diff --git a/arch/csky/kernel/ftrace.c b/arch/csky/kernel/ftrace.c index ad054f7190f9..274c431f1810 100644 --- a/arch/csky/kernel/ftrace.c +++ b/arch/csky/kernel/ftrace.c @@ -4,21 +4,47 @@ #include <linux/ftrace.h> #include <linux/uaccess.h> -extern void (*ftrace_trace_function)(unsigned long, unsigned long, - struct ftrace_ops*, struct pt_regs*); +#ifdef CONFIG_FUNCTION_GRAPH_TRACER +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; + if (unlikely(atomic_read(¤t->tracing_graph_pause))) + return; -noinline void __naked ftrace_stub(unsigned long ip, unsigned long parent_ip, - struct ftrace_ops *op, struct pt_regs *regs) -{ - asm volatile ("\n"); -} + old = *parent; -noinline void csky_mcount(unsigned long from_pc, unsigned long self_pc) -{ - if (ftrace_trace_function != ftrace_stub) - ftrace_trace_function(self_pc, from_pc, NULL, NULL); + if (!function_graph_enter(old, self_addr, + *(unsigned long *)frame_pointer, parent)) { + /* + * For csky-gcc function has sub-call: + * subi sp, sp, 8 + * stw r8, (sp, 0) + * mov r8, sp + * st.w r15, (sp, 0x4) + * push r15 + * jl _mcount + * We only need set *parent for resume + * + * For csky-gcc function has no sub-call: + * subi sp, sp, 4 + * stw r8, (sp, 0) + * mov r8, sp + * push r15 + * jl _mcount + * We need set *parent and *(frame_pointer + 4) for resume, + * because lr is resumed twice. + */ + *parent = return_hooker; + frame_pointer += 4; + if (*(unsigned long *)frame_pointer == old) + *(unsigned long *)frame_pointer = return_hooker; + } } +#endif /* _mcount is defined in abi's mcount.S */ +extern void _mcount(void); EXPORT_SYMBOL(_mcount); |