On Fri, 31 Oct 2025 10:40:38 +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]> > --- > v2: > - remove the definition of FPROBE_USE_FTRACE > --- > kernel/trace/fprobe.c | 30 +++++++++++++++++++----------- > 1 file changed, 19 insertions(+), 11 deletions(-) > > diff --git a/kernel/trace/fprobe.c b/kernel/trace/fprobe.c > index ecd623eef68b..742ad5a61d46 100644 > --- a/kernel/trace/fprobe.c > +++ b/kernel/trace/fprobe.c > @@ -44,6 +44,7 @@ > static struct hlist_head fprobe_table[FPROBE_TABLE_SIZE]; > static struct rhltable fprobe_ip_table; > static DEFINE_MUTEX(fprobe_mutex); > +static struct fgraph_ops fprobe_graph_ops; > > static u32 fprobe_node_hashfn(const void *data, u32 len, u32 seed) > { > @@ -254,7 +255,7 @@ 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) > /* 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 +296,7 @@ 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; > > @@ -335,6 +336,13 @@ static bool fprobe_is_ftrace(struct fprobe *fp) > { > return !fp->exit_handler; > } > + Ah, the new function depends on MODULES. #ifdef CONFIG_MODULES > +static void fprobe_set_ips(unsigned long *ips, unsigned int cnt, int remove, > + int reset) > +{ > + ftrace_set_filter_ips(&fprobe_graph_ops.ops, ips, cnt, remove, reset); > + ftrace_set_filter_ips(&fprobe_ftrace_ops, ips, cnt, remove, reset); > +} #endif /* CONFIG_MODULES */ > #else #ifdef CONFIG_MODULES > static int fprobe_ftrace_add_ips(unsigned long *addrs, int num) > { > @@ -349,7 +357,13 @@ static bool fprobe_is_ftrace(struct fprobe *fp) > { > return false; > } #endif /* CONFIG_MODULES */ are needed. Thank you, > -#endif > + > +static void fprobe_set_ips(unsigned long *ips, unsigned int cnt, int remove, > + int reset) > +{ > + ftrace_set_filter_ips(&fprobe_graph_ops.ops, ips, cnt, remove, reset); > +} > +#endif /* !CONFIG_DYNAMIC_FTRACE_WITH_ARGS && > !CONFIG_DYNAMIC_FTRACE_WITH_REGS */ > > /* fgraph_ops callback, this processes fprobes which have exit_handler. */ > static int fprobe_fgraph_entry(struct ftrace_graph_ent *trace, struct > fgraph_ops *gops, > @@ -596,14 +610,8 @@ static int fprobe_module_callback(struct notifier_block > *nb, > } while (node == ERR_PTR(-EAGAIN)); > rhashtable_walk_exit(&iter); > > - if (alist.index > 0) { > - ftrace_set_filter_ips(&fprobe_graph_ops.ops, > - alist.addrs, alist.index, 1, 0); > -#ifdef CONFIG_DYNAMIC_FTRACE_WITH_REGS > - ftrace_set_filter_ips(&fprobe_ftrace_ops, > - alist.addrs, alist.index, 1, 0); > -#endif > - } > + if (alist.index > 0) > + fprobe_set_ips(alist.addrs, alist.index, 1, 0); > mutex_unlock(&fprobe_mutex); > > kfree(alist.addrs); > -- > 2.51.2 > -- Masami Hiramatsu (Google) <[email protected]>
