On Wed, Jul 15, 2020 at 05:35:24PM +0900, Masami Hiramatsu wrote: > Hi Jarkko, > > On Wed, 15 Jul 2020 01:32:29 +0300 > Jarkko Sakkinen <[email protected]> wrote: > > > Remove CONFIG_MODULES dependency by flagging out the dependent code. This > > allows to use kprobes in a kernel without support for loadable modules, > > which could be useful for a test kernel or perhaps an embedded kernel. > > > > OK, looks good, I just have 2 comments below. > > > Cc: Andi Kleen <[email protected]> > > Signed-off-by: Jarkko Sakkinen <[email protected]> > > --- > > include/linux/module.h | 14 +++++++------- > > kernel/kprobes.c | 7 +++++++ > > kernel/trace/trace_kprobe.c | 16 +++++++++++++++- > > 3 files changed, 29 insertions(+), 8 deletions(-) > > > > diff --git a/include/linux/module.h b/include/linux/module.h > > index 857b84bf9e90..eaa8ad02f75c 100644 > > --- a/include/linux/module.h > > +++ b/include/linux/module.h > > @@ -290,6 +290,13 @@ extern typeof(name) > > __mod_##type##__##name##_device_table \ > > > > struct notifier_block; > > > > +enum module_state { > > + MODULE_STATE_LIVE, /* Normal state. */ > > + MODULE_STATE_COMING, /* Full formed, running module_init. */ > > + MODULE_STATE_GOING, /* Going away. */ > > + MODULE_STATE_UNFORMED, /* Still setting it up. */ > > +}; > > + > > #ifdef CONFIG_MODULES > > > > extern int modules_disabled; /* for sysctl */ > > @@ -305,13 +312,6 @@ struct module_use { > > struct module *source, *target; > > }; > > > > -enum module_state { > > - MODULE_STATE_LIVE, /* Normal state. */ > > - MODULE_STATE_COMING, /* Full formed, running module_init. */ > > - MODULE_STATE_GOING, /* Going away. */ > > - MODULE_STATE_UNFORMED, /* Still setting it up. */ > > -}; > > - > > struct mod_tree_node { > > struct module *mod; > > struct latch_tree_node node; > > diff --git a/kernel/kprobes.c b/kernel/kprobes.c > > index b4f3c24cd2ef..3039df13d34e 100644 > > --- a/kernel/kprobes.c > > +++ b/kernel/kprobes.c > > @@ -2225,6 +2225,7 @@ int kprobe_add_area_blacklist(unsigned long start, > > unsigned long end) > > return 0; > > } > > > > +#ifdef CONFIG_MODULES > > /* Remove all symbols in given area from kprobe blacklist */ > > static void kprobe_remove_area_blacklist(unsigned long start, unsigned > > long end) > > { > > @@ -2242,6 +2243,7 @@ static void kprobe_remove_ksym_blacklist(unsigned > > long entry) > > { > > kprobe_remove_area_blacklist(entry, entry + 1); > > } > > +#endif > > > > int __init __weak arch_populate_kprobe_blacklist(void) > > { > > @@ -2285,6 +2287,7 @@ static int __init populate_kprobe_blacklist(unsigned > > long *start, > > return ret ? : arch_populate_kprobe_blacklist(); > > } > > > > +#ifdef CONFIG_MODULES > > static void add_module_kprobe_blacklist(struct module *mod) > > { > > unsigned long start, end; > > @@ -2330,6 +2333,10 @@ static void remove_module_kprobe_blacklist(struct > > module *mod) > > kprobe_remove_area_blacklist(start, end); > > } > > } > > +#else > > +static void add_module_kprobe_blacklist(struct module *mod) {} > > +static void remove_module_kprobe_blacklist(struct module *mod) {} > > +#endif /* CONFIG_MODULES */ > > Please feel free to move the function. I would like to see; > > #ifdef CONFIG_MODULES > /* Remove all symbols in given area from kprobe blacklist */ > static void kprobe_remove_area_blacklist(unsigned long start, unsigned long > end) > { > ... > } > static void add_module_kprobe_blacklist(struct module *mod) > { > ... > } > #else > static void add_module_kprobe_blacklist(struct module *mod) {} > static void remove_module_kprobe_blacklist(struct module *mod) {} > #endif /* CONFIG_MODULES */ > > Rather than split #ifdefs. > > > > > /* Module notifier call back, checking kprobes on the module */ > > static int kprobes_module_callback(struct notifier_block *nb, > > diff --git a/kernel/trace/trace_kprobe.c b/kernel/trace/trace_kprobe.c > > index 710ec6a6aa8f..7fcd1bf2d96e 100644 > > --- a/kernel/trace/trace_kprobe.c > > +++ b/kernel/trace/trace_kprobe.c > > @@ -103,8 +103,9 @@ static nokprobe_inline bool > > trace_kprobe_has_gone(struct trace_kprobe *tk) > > return !!(kprobe_gone(&tk->rp.kp)); > > } > > > > +#ifdef CONFIG_MODULES > > static nokprobe_inline bool trace_kprobe_within_module(struct trace_kprobe > > *tk, > > - struct module *mod) > > + struct module *mod) > > { > > int len = strlen(mod->name); > > const char *name = trace_kprobe_symbol(tk); > > @@ -129,6 +130,17 @@ static nokprobe_inline bool > > trace_kprobe_module_exist(struct trace_kprobe *tk) > > > > return ret; > > } > > +#else > > +static nokprobe_inline bool trace_kprobe_within_module(struct trace_kprobe > > *tk, > > + struct module *mod) > > +{ > > + return false; > > +} > > +static nokprobe_inline bool trace_kprobe_module_exist(struct trace_kprobe > > *tk) > > +{ > > + return false; > > +} > > +#endif > > > > static bool trace_kprobe_is_busy(struct dyn_event *ev) > > { > > @@ -685,10 +697,12 @@ static int trace_kprobe_module_callback(struct > > notifier_block *nb, > > /* Don't need to check busy - this should have gone. */ > > __unregister_trace_kprobe(tk); > > ret = __register_trace_kprobe(tk); > > +#ifdef CONFIG_MODULES > > if (ret) > > pr_warn("Failed to re-register probe %s on %s: > > %d\n", > > trace_probe_name(&tk->tp), > > mod->name, ret); > > +#endif > > I guess this CONFIG_MODULES is for avoiding build error according to > mod->name, > if so, please use module_name(mod) macro instead of this #ifdef. > > > } > > } > > mutex_unlock(&event_mutex); > > -- > > 2.25.1 > > > > > -- > Masami Hiramatsu <[email protected]>
Thanks, agree with the remarks. /Jarkko
