On Wed, 29 Oct 2025 10:15:14 +0800 Menglong Dong <[email protected]> wrote:
> 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 Instead of introducing FPROBE_USE_FTRACE, I think it is better to add another wrapper to be called here. #if defined(CONFIG_DYNAMIC_FTRACE_WITH_ARGS) || defined(CONFIG_DYNAMIC_FTRACE_WITH_REGS) static void fprobe_set_ips(unsigned long *ips, unsigned int cnt, int remove, int reset) { ftrace_set_filter_ips(&fprobe_graph_ops.ops, alist.addrs, alist.index, 1, 0); ftrace_set_filter_ips(&fprobe_ftrace_ops, alist.addrs, alist.index, 1, 0); } ... #else static void fprobe_set_ips(unsigned long *ips, unsigned int cnt, int remove, int reset) { ftrace_set_filter_ips(&fprobe_graph_ops.ops, alist.addrs, alist.index, 1, 0); } #endif Thank you, -- Masami Hiramatsu (Google) <[email protected]>
