For now, we will use ftrace for the fprobe if fp->exit_handler not exists and CONFIG_DYNAMIC_FTRACE_WITH_REGS is enabled.
However, CONFIG_DYNAMIC_FTRACE_WITH_REGS is not supported by some arch, such as arm. What we need in the fprobe is the function arguments, so we can use ftrace for fprobe if CONFIG_DYNAMIC_FTRACE_WITH_ARGS is enabled. Therefore, use ftrace if CONFIG_DYNAMIC_FTRACE_WITH_REGS or CONFIG_DYNAMIC_FTRACE_WITH_ARGS enabled. Signed-off-by: Menglong Dong <[email protected]> --- kernel/trace/fprobe.c | 12 ++++++++---- 1 file changed, 8 insertions(+), 4 deletions(-) diff --git a/kernel/trace/fprobe.c b/kernel/trace/fprobe.c index ecd623eef68b..9fad0569f521 100644 --- a/kernel/trace/fprobe.c +++ b/kernel/trace/fprobe.c @@ -254,7 +254,11 @@ static inline int __fprobe_kprobe_handler(unsigned long ip, unsigned long parent return ret; } -#ifdef CONFIG_DYNAMIC_FTRACE_WITH_REGS +#if defined(CONFIG_DYNAMIC_FTRACE_WITH_ARGS) || defined(CONFIG_DYNAMIC_FTRACE_WITH_REGS) +#define FPROBE_USE_FTRACE +#endif + +#ifdef FPROBE_USE_FTRACE /* ftrace_ops callback, this processes fprobes which have only entry_handler. */ static void fprobe_ftrace_entry(unsigned long ip, unsigned long parent_ip, struct ftrace_ops *ops, struct ftrace_regs *fregs) @@ -295,7 +299,7 @@ NOKPROBE_SYMBOL(fprobe_ftrace_entry); static struct ftrace_ops fprobe_ftrace_ops = { .func = fprobe_ftrace_entry, - .flags = FTRACE_OPS_FL_SAVE_REGS, + .flags = FTRACE_OPS_FL_SAVE_ARGS, }; static int fprobe_ftrace_active; @@ -349,7 +353,7 @@ static bool fprobe_is_ftrace(struct fprobe *fp) { return false; } -#endif +#endif /* !FPROBE_USE_FTRACE */ /* fgraph_ops callback, this processes fprobes which have exit_handler. */ static int fprobe_fgraph_entry(struct ftrace_graph_ent *trace, struct fgraph_ops *gops, @@ -599,7 +603,7 @@ static int fprobe_module_callback(struct notifier_block *nb, if (alist.index > 0) { ftrace_set_filter_ips(&fprobe_graph_ops.ops, alist.addrs, alist.index, 1, 0); -#ifdef CONFIG_DYNAMIC_FTRACE_WITH_REGS +#ifdef FPROBE_USE_FTRACE ftrace_set_filter_ips(&fprobe_ftrace_ops, alist.addrs, alist.index, 1, 0); #endif -- 2.51.1
