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]>
