| Message ID | 2af01251ca21d79fa29092505d192f1f1b746cff.1709676663.git.jcalvinowens@gmail.com (mailing list archive) |
|---|---|
| State | RFC |
| Headers | show |
| Series | Make bpf_jit and kprobes work with CONFIG_MODULES=n | expand |
On Wed, Mar 06, 2024 at 12:05:10PM -0800, Calvin Owens wrote: > If something like this is merged down the road, it can go in at leisure > once the module_alloc change is in: it's a one-way dependency. > > Signed-off-by: Calvin Owens <jcalvinowens@gmail.com> > --- > arch/Kconfig | 2 +- > kernel/kprobes.c | 22 ++++++++++++++++++++++ > kernel/trace/trace_kprobe.c | 11 +++++++++++ > 3 files changed, 34 insertions(+), 1 deletion(-) When I did this in my last execmem posting, I think I've got slightly less ugly ifdery, you may want to take a look at that: https://lore.kernel.org/all/20230918072955.2507221-13-rppt@kernel.org > diff --git a/arch/Kconfig b/arch/Kconfig > index cfc24ced16dd..e60ce984d095 100644 > --- a/arch/Kconfig > +++ b/arch/Kconfig > @@ -52,8 +52,8 @@ config GENERIC_ENTRY > > config KPROBES > bool "Kprobes" > - depends on MODULES > depends on HAVE_KPROBES > + select MODULE_ALLOC > select KALLSYMS > select TASKS_RCU if PREEMPTION > help > diff --git a/kernel/kprobes.c b/kernel/kprobes.c > index 9d9095e81792..194270e17d57 100644 > --- a/kernel/kprobes.c > +++ b/kernel/kprobes.c > @@ -1556,8 +1556,12 @@ static bool is_cfi_preamble_symbol(unsigned long addr) > str_has_prefix("__pfx_", symbuf); > } > > +#if IS_ENABLED(CONFIG_MODULES) > static int check_kprobe_address_safe(struct kprobe *p, > struct module **probed_mod) > +#else > +static int check_kprobe_address_safe(struct kprobe *p) > +#endif > { > int ret; > > @@ -1580,6 +1584,7 @@ static int check_kprobe_address_safe(struct kprobe *p, > goto out; > } > > +#if IS_ENABLED(CONFIG_MODULES) Plain #ifdef will do here and below. IS_ENABLED is for usage withing the code, like if (IS_ENABLED(CONFIG_MODULES)) ; > /* Check if 'p' is probing a module. */ > *probed_mod = __module_text_address((unsigned long) p->addr); > if (*probed_mod) {
Le 06/03/2024 à 21:05, Calvin Owens a écrit : > [Vous ne recevez pas souvent de courriers de jcalvinowens@gmail.com. Découvrez pourquoi ceci est important à https://aka.ms/LearnAboutSenderIdentification ] > > If something like this is merged down the road, it can go in at leisure > once the module_alloc change is in: it's a one-way dependency. Too many #ifdef, please reorganise stuff to avoid that and avoid changing prototypes based of CONFIG_MODULES. Other few comments below. > > Signed-off-by: Calvin Owens <jcalvinowens@gmail.com> > --- > arch/Kconfig | 2 +- > kernel/kprobes.c | 22 ++++++++++++++++++++++ > kernel/trace/trace_kprobe.c | 11 +++++++++++ > 3 files changed, 34 insertions(+), 1 deletion(-) > > diff --git a/arch/Kconfig b/arch/Kconfig > index cfc24ced16dd..e60ce984d095 100644 > --- a/arch/Kconfig > +++ b/arch/Kconfig > @@ -52,8 +52,8 @@ config GENERIC_ENTRY > > config KPROBES > bool "Kprobes" > - depends on MODULES > depends on HAVE_KPROBES > + select MODULE_ALLOC > select KALLSYMS > select TASKS_RCU if PREEMPTION > help > diff --git a/kernel/kprobes.c b/kernel/kprobes.c > index 9d9095e81792..194270e17d57 100644 > --- a/kernel/kprobes.c > +++ b/kernel/kprobes.c > @@ -1556,8 +1556,12 @@ static bool is_cfi_preamble_symbol(unsigned long addr) > str_has_prefix("__pfx_", symbuf); > } > > +#if IS_ENABLED(CONFIG_MODULES) > static int check_kprobe_address_safe(struct kprobe *p, > struct module **probed_mod) > +#else > +static int check_kprobe_address_safe(struct kprobe *p) > +#endif A bit ugly to have to change the prototype, why not just keep probed_mod at all time ? When CONFIG_MODULES is not selected, __module_text_address() returns NULL so it should work without that many #ifdefs. > { > int ret; > > @@ -1580,6 +1584,7 @@ static int check_kprobe_address_safe(struct kprobe *p, > goto out; > } > > +#if IS_ENABLED(CONFIG_MODULES) > /* Check if 'p' is probing a module. */ > *probed_mod = __module_text_address((unsigned long) p->addr); > if (*probed_mod) { > @@ -1603,6 +1608,8 @@ static int check_kprobe_address_safe(struct kprobe *p, > ret = -ENOENT; > } > } > +#endif > + > out: > preempt_enable(); > jump_label_unlock(); > @@ -1614,7 +1621,9 @@ int register_kprobe(struct kprobe *p) > { > int ret; > struct kprobe *old_p; > +#if IS_ENABLED(CONFIG_MODULES) > struct module *probed_mod; > +#endif > kprobe_opcode_t *addr; > bool on_func_entry; > > @@ -1633,7 +1642,11 @@ int register_kprobe(struct kprobe *p) > p->nmissed = 0; > INIT_LIST_HEAD(&p->list); > > +#if IS_ENABLED(CONFIG_MODULES) > ret = check_kprobe_address_safe(p, &probed_mod); > +#else > + ret = check_kprobe_address_safe(p); > +#endif > if (ret) > return ret; > > @@ -1676,8 +1689,10 @@ int register_kprobe(struct kprobe *p) > out: > mutex_unlock(&kprobe_mutex); > > +#if IS_ENABLED(CONFIG_MODULES) > if (probed_mod) > module_put(probed_mod); > +#endif > > return ret; > } > @@ -2482,6 +2497,7 @@ int kprobe_add_area_blacklist(unsigned long start, unsigned long end) > return 0; > } > > +#if IS_ENABLED(CONFIG_MODULES) > /* Remove all symbols in given area from kprobe blacklist */ > static void kprobe_remove_area_blacklist(unsigned long start, unsigned long end) > { > @@ -2499,6 +2515,7 @@ static void kprobe_remove_ksym_blacklist(unsigned long entry) > { > kprobe_remove_area_blacklist(entry, entry + 1); > } > +#endif > > int __weak arch_kprobe_get_kallsym(unsigned int *symnum, unsigned long *value, > char *type, char *sym) > @@ -2564,6 +2581,7 @@ static int __init populate_kprobe_blacklist(unsigned long *start, > return ret ? : arch_populate_kprobe_blacklist(); > } > > +#if IS_ENABLED(CONFIG_MODULES) > static void add_module_kprobe_blacklist(struct module *mod) > { > unsigned long start, end; > @@ -2665,6 +2683,7 @@ static struct notifier_block kprobe_module_nb = { > .notifier_call = kprobes_module_callback, > .priority = 0 > }; > +#endif /* IS_ENABLED(CONFIG_MODULES) */ > > void kprobe_free_init_mem(void) > { > @@ -2724,8 +2743,11 @@ static int __init init_kprobes(void) > err = arch_init_kprobes(); > if (!err) > err = register_die_notifier(&kprobe_exceptions_nb); > + > +#if IS_ENABLED(CONFIG_MODULES) > if (!err) > err = register_module_notifier(&kprobe_module_nb); > +#endif > > kprobes_initialized = (err == 0); > kprobe_sysctls_init(); > diff --git a/kernel/trace/trace_kprobe.c b/kernel/trace/trace_kprobe.c > index c4c6e0e0068b..dd4598f775b9 100644 > --- a/kernel/trace/trace_kprobe.c > +++ b/kernel/trace/trace_kprobe.c > @@ -102,6 +102,7 @@ static nokprobe_inline bool trace_kprobe_has_gone(struct trace_kprobe *tk) > return kprobe_gone(&tk->rp.kp); > } > > +#if IS_ENABLED(CONFIG_MODULES) > static nokprobe_inline bool trace_kprobe_within_module(struct trace_kprobe *tk, > struct module *mod) > { > @@ -129,6 +130,12 @@ static nokprobe_inline bool trace_kprobe_module_exist(struct trace_kprobe *tk) > > return ret; > } > +#else > +static nokprobe_inline bool trace_kprobe_module_exist(struct trace_kprobe *tk) > +{ > + return true; > +} > +#endif > > static bool trace_kprobe_is_busy(struct dyn_event *ev) > { > @@ -670,6 +677,7 @@ static int register_trace_kprobe(struct trace_kprobe *tk) > return ret; > } > > +#if IS_ENABLED(CONFIG_MODULES) > /* Module notifier call back, checking event on the module */ > static int trace_kprobe_module_callback(struct notifier_block *nb, > unsigned long val, void *data) > @@ -704,6 +712,7 @@ static struct notifier_block trace_kprobe_module_nb = { > .notifier_call = trace_kprobe_module_callback, > .priority = 1 /* Invoked after kprobe module callback */ > }; > +#endif /* IS_ENABLED(CONFIG_MODULES) */ > > static int count_symbols(void *data, unsigned long unused) > { > @@ -1897,8 +1906,10 @@ static __init int init_kprobe_trace_early(void) > if (ret) > return ret; > > +#if IS_ENABLED(CONFIG_MODULES) > if (register_module_notifier(&trace_kprobe_module_nb)) > return -EINVAL; Why a #if here ? If CONFIG_MODULES is not selected, register_module_notifier() return always 0. > +#endif > > return 0; > } > -- > 2.43.0 > >
On Wed, 6 Mar 2024 12:05:10 -0800 Calvin Owens <jcalvinowens@gmail.com> wrote: > If something like this is merged down the road, it can go in at leisure > once the module_alloc change is in: it's a one-way dependency. > > Signed-off-by: Calvin Owens <jcalvinowens@gmail.com> > --- > arch/Kconfig | 2 +- > kernel/kprobes.c | 22 ++++++++++++++++++++++ > kernel/trace/trace_kprobe.c | 11 +++++++++++ > 3 files changed, 34 insertions(+), 1 deletion(-) > > diff --git a/arch/Kconfig b/arch/Kconfig > index cfc24ced16dd..e60ce984d095 100644 > --- a/arch/Kconfig > +++ b/arch/Kconfig > @@ -52,8 +52,8 @@ config GENERIC_ENTRY > > config KPROBES > bool "Kprobes" > - depends on MODULES > depends on HAVE_KPROBES > + select MODULE_ALLOC OK, if we use EXEC_ALLOC, config EXEC_ALLOC depends on HAVE_EXEC_ALLOC And config KPROBES bool "Kprobes" depends on MODULES || EXEC_ALLOC select EXEC_ALLOC if HAVE_EXEC_ALLOC then kprobes can be enabled either modules supported or exec_alloc is supported. (new arch does not need to implement exec_alloc) Maybe we also need something like #ifdef CONFIG_EXEC_ALLOC #define module_alloc(size) exec_alloc(size) #endif in kprobes.h, or just add `replacing module_alloc with exec_alloc` patch. Thank you, > select KALLSYMS > select TASKS_RCU if PREEMPTION > help > diff --git a/kernel/kprobes.c b/kernel/kprobes.c > index 9d9095e81792..194270e17d57 100644 > --- a/kernel/kprobes.c > +++ b/kernel/kprobes.c > @@ -1556,8 +1556,12 @@ static bool is_cfi_preamble_symbol(unsigned long addr) > str_has_prefix("__pfx_", symbuf); > } > > +#if IS_ENABLED(CONFIG_MODULES) > static int check_kprobe_address_safe(struct kprobe *p, > struct module **probed_mod) > +#else > +static int check_kprobe_address_safe(struct kprobe *p) > +#endif > { > int ret; > > @@ -1580,6 +1584,7 @@ static int check_kprobe_address_safe(struct kprobe *p, > goto out; > } > > +#if IS_ENABLED(CONFIG_MODULES) > /* Check if 'p' is probing a module. */ > *probed_mod = __module_text_address((unsigned long) p->addr); > if (*probed_mod) { > @@ -1603,6 +1608,8 @@ static int check_kprobe_address_safe(struct kprobe *p, > ret = -ENOENT; > } > } > +#endif > + > out: > preempt_enable(); > jump_label_unlock(); > @@ -1614,7 +1621,9 @@ int register_kprobe(struct kprobe *p) > { > int ret; > struct kprobe *old_p; > +#if IS_ENABLED(CONFIG_MODULES) > struct module *probed_mod; > +#endif > kprobe_opcode_t *addr; > bool on_func_entry; > > @@ -1633,7 +1642,11 @@ int register_kprobe(struct kprobe *p) > p->nmissed = 0; > INIT_LIST_HEAD(&p->list); > > +#if IS_ENABLED(CONFIG_MODULES) > ret = check_kprobe_address_safe(p, &probed_mod); > +#else > + ret = check_kprobe_address_safe(p); > +#endif > if (ret) > return ret; > > @@ -1676,8 +1689,10 @@ int register_kprobe(struct kprobe *p) > out: > mutex_unlock(&kprobe_mutex); > > +#if IS_ENABLED(CONFIG_MODULES) > if (probed_mod) > module_put(probed_mod); > +#endif > > return ret; > } > @@ -2482,6 +2497,7 @@ int kprobe_add_area_blacklist(unsigned long start, unsigned long end) > return 0; > } > > +#if IS_ENABLED(CONFIG_MODULES) > /* Remove all symbols in given area from kprobe blacklist */ > static void kprobe_remove_area_blacklist(unsigned long start, unsigned long end) > { > @@ -2499,6 +2515,7 @@ static void kprobe_remove_ksym_blacklist(unsigned long entry) > { > kprobe_remove_area_blacklist(entry, entry + 1); > } > +#endif > > int __weak arch_kprobe_get_kallsym(unsigned int *symnum, unsigned long *value, > char *type, char *sym) > @@ -2564,6 +2581,7 @@ static int __init populate_kprobe_blacklist(unsigned long *start, > return ret ? : arch_populate_kprobe_blacklist(); > } > > +#if IS_ENABLED(CONFIG_MODULES) > static void add_module_kprobe_blacklist(struct module *mod) > { > unsigned long start, end; > @@ -2665,6 +2683,7 @@ static struct notifier_block kprobe_module_nb = { > .notifier_call = kprobes_module_callback, > .priority = 0 > }; > +#endif /* IS_ENABLED(CONFIG_MODULES) */ > > void kprobe_free_init_mem(void) > { > @@ -2724,8 +2743,11 @@ static int __init init_kprobes(void) > err = arch_init_kprobes(); > if (!err) > err = register_die_notifier(&kprobe_exceptions_nb); > + > +#if IS_ENABLED(CONFIG_MODULES) > if (!err) > err = register_module_notifier(&kprobe_module_nb); > +#endif > > kprobes_initialized = (err == 0); > kprobe_sysctls_init(); > diff --git a/kernel/trace/trace_kprobe.c b/kernel/trace/trace_kprobe.c > index c4c6e0e0068b..dd4598f775b9 100644 > --- a/kernel/trace/trace_kprobe.c > +++ b/kernel/trace/trace_kprobe.c > @@ -102,6 +102,7 @@ static nokprobe_inline bool trace_kprobe_has_gone(struct trace_kprobe *tk) > return kprobe_gone(&tk->rp.kp); > } > > +#if IS_ENABLED(CONFIG_MODULES) > static nokprobe_inline bool trace_kprobe_within_module(struct trace_kprobe *tk, > struct module *mod) > { > @@ -129,6 +130,12 @@ static nokprobe_inline bool trace_kprobe_module_exist(struct trace_kprobe *tk) > > return ret; > } > +#else > +static nokprobe_inline bool trace_kprobe_module_exist(struct trace_kprobe *tk) > +{ > + return true; > +} > +#endif > > static bool trace_kprobe_is_busy(struct dyn_event *ev) > { > @@ -670,6 +677,7 @@ static int register_trace_kprobe(struct trace_kprobe *tk) > return ret; > } > > +#if IS_ENABLED(CONFIG_MODULES) > /* Module notifier call back, checking event on the module */ > static int trace_kprobe_module_callback(struct notifier_block *nb, > unsigned long val, void *data) > @@ -704,6 +712,7 @@ static struct notifier_block trace_kprobe_module_nb = { > .notifier_call = trace_kprobe_module_callback, > .priority = 1 /* Invoked after kprobe module callback */ > }; > +#endif /* IS_ENABLED(CONFIG_MODULES) */ > > static int count_symbols(void *data, unsigned long unused) > { > @@ -1897,8 +1906,10 @@ static __init int init_kprobe_trace_early(void) > if (ret) > return ret; > > +#if IS_ENABLED(CONFIG_MODULES) > if (register_module_notifier(&trace_kprobe_module_nb)) > return -EINVAL; > +#endif > > return 0; > } > -- > 2.43.0 >
On Thu, 7 Mar 2024 09:22:07 +0200 Mike Rapoport <rppt@kernel.org> wrote: > On Wed, Mar 06, 2024 at 12:05:10PM -0800, Calvin Owens wrote: > > If something like this is merged down the road, it can go in at leisure > > once the module_alloc change is in: it's a one-way dependency. > > > > Signed-off-by: Calvin Owens <jcalvinowens@gmail.com> > > --- > > arch/Kconfig | 2 +- > > kernel/kprobes.c | 22 ++++++++++++++++++++++ > > kernel/trace/trace_kprobe.c | 11 +++++++++++ > > 3 files changed, 34 insertions(+), 1 deletion(-) > > When I did this in my last execmem posting, I think I've got slightly less > ugly ifdery, you may want to take a look at that: > > https://lore.kernel.org/all/20230918072955.2507221-13-rppt@kernel.org Good catch, and sorry I missed that series last year. But it seems your patch seems less ugly. Calvin, can you follow his patch? Thank you, > > > diff --git a/arch/Kconfig b/arch/Kconfig > > index cfc24ced16dd..e60ce984d095 100644 > > --- a/arch/Kconfig > > +++ b/arch/Kconfig > > @@ -52,8 +52,8 @@ config GENERIC_ENTRY > > > > config KPROBES > > bool "Kprobes" > > - depends on MODULES > > depends on HAVE_KPROBES > > + select MODULE_ALLOC > > select KALLSYMS > > select TASKS_RCU if PREEMPTION > > help > > diff --git a/kernel/kprobes.c b/kernel/kprobes.c > > index 9d9095e81792..194270e17d57 100644 > > --- a/kernel/kprobes.c > > +++ b/kernel/kprobes.c > > @@ -1556,8 +1556,12 @@ static bool is_cfi_preamble_symbol(unsigned long addr) > > str_has_prefix("__pfx_", symbuf); > > } > > > > +#if IS_ENABLED(CONFIG_MODULES) > > static int check_kprobe_address_safe(struct kprobe *p, > > struct module **probed_mod) > > +#else > > +static int check_kprobe_address_safe(struct kprobe *p) > > +#endif > > { > > int ret; > > > > @@ -1580,6 +1584,7 @@ static int check_kprobe_address_safe(struct kprobe *p, > > goto out; > > } > > > > +#if IS_ENABLED(CONFIG_MODULES) > > Plain #ifdef will do here and below. IS_ENABLED is for usage withing the > code, like > > if (IS_ENABLED(CONFIG_MODULES)) > ; > > > /* Check if 'p' is probing a module. */ > > *probed_mod = __module_text_address((unsigned long) p->addr); > > if (*probed_mod) { > > -- > Sincerely yours, > Mike.
On Thursday 03/07 at 09:22 +0200, Mike Rapoport wrote: > On Wed, Mar 06, 2024 at 12:05:10PM -0800, Calvin Owens wrote: > > If something like this is merged down the road, it can go in at leisure > > once the module_alloc change is in: it's a one-way dependency. > > > > Signed-off-by: Calvin Owens <jcalvinowens@gmail.com> > > --- > > arch/Kconfig | 2 +- > > kernel/kprobes.c | 22 ++++++++++++++++++++++ > > kernel/trace/trace_kprobe.c | 11 +++++++++++ > > 3 files changed, 34 insertions(+), 1 deletion(-) > > When I did this in my last execmem posting, I think I've got slightly less > ugly ifdery, you may want to take a look at that: > > https://lore.kernel.org/all/20230918072955.2507221-13-rppt@kernel.org Thanks Mike, I definitely agree. I'm annoyed at myself for not finding your patches, I spent some time looking for prior work and I really don't know how I missed it... > > diff --git a/arch/Kconfig b/arch/Kconfig > > index cfc24ced16dd..e60ce984d095 100644 > > --- a/arch/Kconfig > > +++ b/arch/Kconfig > > @@ -52,8 +52,8 @@ config GENERIC_ENTRY > > > > config KPROBES > > bool "Kprobes" > > - depends on MODULES > > depends on HAVE_KPROBES > > + select MODULE_ALLOC > > select KALLSYMS > > select TASKS_RCU if PREEMPTION > > help > > diff --git a/kernel/kprobes.c b/kernel/kprobes.c > > index 9d9095e81792..194270e17d57 100644 > > --- a/kernel/kprobes.c > > +++ b/kernel/kprobes.c > > @@ -1556,8 +1556,12 @@ static bool is_cfi_preamble_symbol(unsigned long addr) > > str_has_prefix("__pfx_", symbuf); > > } > > > > +#if IS_ENABLED(CONFIG_MODULES) > > static int check_kprobe_address_safe(struct kprobe *p, > > struct module **probed_mod) > > +#else > > +static int check_kprobe_address_safe(struct kprobe *p) > > +#endif > > { > > int ret; > > > > @@ -1580,6 +1584,7 @@ static int check_kprobe_address_safe(struct kprobe *p, > > goto out; > > } > > > > +#if IS_ENABLED(CONFIG_MODULES) > > Plain #ifdef will do here and below. IS_ENABLED is for usage withing the > code, like > > if (IS_ENABLED(CONFIG_MODULES)) > ; > > > /* Check if 'p' is probing a module. */ > > *probed_mod = __module_text_address((unsigned long) p->addr); > > if (*probed_mod) { > > -- > Sincerely yours, > Mike.
On Friday 03/08 at 11:46 +0900, Masami Hiramatsu wrote: > On Wed, 6 Mar 2024 12:05:10 -0800 > Calvin Owens <jcalvinowens@gmail.com> wrote: > > > If something like this is merged down the road, it can go in at leisure > > once the module_alloc change is in: it's a one-way dependency. > > > > Signed-off-by: Calvin Owens <jcalvinowens@gmail.com> > > --- > > arch/Kconfig | 2 +- > > kernel/kprobes.c | 22 ++++++++++++++++++++++ > > kernel/trace/trace_kprobe.c | 11 +++++++++++ > > 3 files changed, 34 insertions(+), 1 deletion(-) > > > > diff --git a/arch/Kconfig b/arch/Kconfig > > index cfc24ced16dd..e60ce984d095 100644 > > --- a/arch/Kconfig > > +++ b/arch/Kconfig > > @@ -52,8 +52,8 @@ config GENERIC_ENTRY > > > > config KPROBES > > bool "Kprobes" > > - depends on MODULES > > depends on HAVE_KPROBES > > + select MODULE_ALLOC > > OK, if we use EXEC_ALLOC, > > config EXEC_ALLOC > depends on HAVE_EXEC_ALLOC > > And > > config KPROBES > bool "Kprobes" > depends on MODULES || EXEC_ALLOC > select EXEC_ALLOC if HAVE_EXEC_ALLOC > > then kprobes can be enabled either modules supported or exec_alloc is supported. > (new arch does not need to implement exec_alloc) > > Maybe we also need something like > > #ifdef CONFIG_EXEC_ALLOC > #define module_alloc(size) exec_alloc(size) > #endif > > in kprobes.h, or just add `replacing module_alloc with exec_alloc` patch. > > Thank you, The example was helpful, thanks. I see what you mean with HAVE_EXEC_ALLOC, I'll implement it like that in the next verison. > > select KALLSYMS > > select TASKS_RCU if PREEMPTION > > help > > diff --git a/kernel/kprobes.c b/kernel/kprobes.c > > index 9d9095e81792..194270e17d57 100644 > > --- a/kernel/kprobes.c > > +++ b/kernel/kprobes.c > > @@ -1556,8 +1556,12 @@ static bool is_cfi_preamble_symbol(unsigned long addr) > > str_has_prefix("__pfx_", symbuf); > > } > > > > +#if IS_ENABLED(CONFIG_MODULES) > > static int check_kprobe_address_safe(struct kprobe *p, > > struct module **probed_mod) > > +#else > > +static int check_kprobe_address_safe(struct kprobe *p) > > +#endif > > { > > int ret; > > > > @@ -1580,6 +1584,7 @@ static int check_kprobe_address_safe(struct kprobe *p, > > goto out; > > } > > > > +#if IS_ENABLED(CONFIG_MODULES) > > /* Check if 'p' is probing a module. */ > > *probed_mod = __module_text_address((unsigned long) p->addr); > > if (*probed_mod) { > > @@ -1603,6 +1608,8 @@ static int check_kprobe_address_safe(struct kprobe *p, > > ret = -ENOENT; > > } > > } > > +#endif > > + > > out: > > preempt_enable(); > > jump_label_unlock(); > > @@ -1614,7 +1621,9 @@ int register_kprobe(struct kprobe *p) > > { > > int ret; > > struct kprobe *old_p; > > +#if IS_ENABLED(CONFIG_MODULES) > > struct module *probed_mod; > > +#endif > > kprobe_opcode_t *addr; > > bool on_func_entry; > > > > @@ -1633,7 +1642,11 @@ int register_kprobe(struct kprobe *p) > > p->nmissed = 0; > > INIT_LIST_HEAD(&p->list); > > > > +#if IS_ENABLED(CONFIG_MODULES) > > ret = check_kprobe_address_safe(p, &probed_mod); > > +#else > > + ret = check_kprobe_address_safe(p); > > +#endif > > if (ret) > > return ret; > > > > @@ -1676,8 +1689,10 @@ int register_kprobe(struct kprobe *p) > > out: > > mutex_unlock(&kprobe_mutex); > > > > +#if IS_ENABLED(CONFIG_MODULES) > > if (probed_mod) > > module_put(probed_mod); > > +#endif > > > > return ret; > > } > > @@ -2482,6 +2497,7 @@ int kprobe_add_area_blacklist(unsigned long start, unsigned long end) > > return 0; > > } > > > > +#if IS_ENABLED(CONFIG_MODULES) > > /* Remove all symbols in given area from kprobe blacklist */ > > static void kprobe_remove_area_blacklist(unsigned long start, unsigned long end) > > { > > @@ -2499,6 +2515,7 @@ static void kprobe_remove_ksym_blacklist(unsigned long entry) > > { > > kprobe_remove_area_blacklist(entry, entry + 1); > > } > > +#endif > > > > int __weak arch_kprobe_get_kallsym(unsigned int *symnum, unsigned long *value, > > char *type, char *sym) > > @@ -2564,6 +2581,7 @@ static int __init populate_kprobe_blacklist(unsigned long *start, > > return ret ? : arch_populate_kprobe_blacklist(); > > } > > > > +#if IS_ENABLED(CONFIG_MODULES) > > static void add_module_kprobe_blacklist(struct module *mod) > > { > > unsigned long start, end; > > @@ -2665,6 +2683,7 @@ static struct notifier_block kprobe_module_nb = { > > .notifier_call = kprobes_module_callback, > > .priority = 0 > > }; > > +#endif /* IS_ENABLED(CONFIG_MODULES) */ > > > > void kprobe_free_init_mem(void) > > { > > @@ -2724,8 +2743,11 @@ static int __init init_kprobes(void) > > err = arch_init_kprobes(); > > if (!err) > > err = register_die_notifier(&kprobe_exceptions_nb); > > + > > +#if IS_ENABLED(CONFIG_MODULES) > > if (!err) > > err = register_module_notifier(&kprobe_module_nb); > > +#endif > > > > kprobes_initialized = (err == 0); > > kprobe_sysctls_init(); > > diff --git a/kernel/trace/trace_kprobe.c b/kernel/trace/trace_kprobe.c > > index c4c6e0e0068b..dd4598f775b9 100644 > > --- a/kernel/trace/trace_kprobe.c > > +++ b/kernel/trace/trace_kprobe.c > > @@ -102,6 +102,7 @@ static nokprobe_inline bool trace_kprobe_has_gone(struct trace_kprobe *tk) > > return kprobe_gone(&tk->rp.kp); > > } > > > > +#if IS_ENABLED(CONFIG_MODULES) > > static nokprobe_inline bool trace_kprobe_within_module(struct trace_kprobe *tk, > > struct module *mod) > > { > > @@ -129,6 +130,12 @@ static nokprobe_inline bool trace_kprobe_module_exist(struct trace_kprobe *tk) > > > > return ret; > > } > > +#else > > +static nokprobe_inline bool trace_kprobe_module_exist(struct trace_kprobe *tk) > > +{ > > + return true; > > +} > > +#endif > > > > static bool trace_kprobe_is_busy(struct dyn_event *ev) > > { > > @@ -670,6 +677,7 @@ static int register_trace_kprobe(struct trace_kprobe *tk) > > return ret; > > } > > > > +#if IS_ENABLED(CONFIG_MODULES) > > /* Module notifier call back, checking event on the module */ > > static int trace_kprobe_module_callback(struct notifier_block *nb, > > unsigned long val, void *data) > > @@ -704,6 +712,7 @@ static struct notifier_block trace_kprobe_module_nb = { > > .notifier_call = trace_kprobe_module_callback, > > .priority = 1 /* Invoked after kprobe module callback */ > > }; > > +#endif /* IS_ENABLED(CONFIG_MODULES) */ > > > > static int count_symbols(void *data, unsigned long unused) > > { > > @@ -1897,8 +1906,10 @@ static __init int init_kprobe_trace_early(void) > > if (ret) > > return ret; > > > > +#if IS_ENABLED(CONFIG_MODULES) > > if (register_module_notifier(&trace_kprobe_module_nb)) > > return -EINVAL; > > +#endif > > > > return 0; > > } > > -- > > 2.43.0 > > > > > -- > Masami Hiramatsu (Google) <mhiramat@kernel.org>
On Thursday 03/07 at 22:16 +0000, Christophe Leroy wrote: > > > Le 06/03/2024 à 21:05, Calvin Owens a écrit : > > [Vous ne recevez pas souvent de courriers de jcalvinowens@gmail.com. Découvrez pourquoi ceci est important à https://aka.ms/LearnAboutSenderIdentification ] > > > > If something like this is merged down the road, it can go in at leisure > > once the module_alloc change is in: it's a one-way dependency. > > Too many #ifdef, please reorganise stuff to avoid that and avoid > changing prototypes based of CONFIG_MODULES. > > Other few comments below. TBH the ugliness here was just me trying not to trigger -Wunused, but that was silly: as you point out below, it's unncessary. I'll clean it up. > > > > Signed-off-by: Calvin Owens <jcalvinowens@gmail.com> > > --- > > arch/Kconfig | 2 +- > > kernel/kprobes.c | 22 ++++++++++++++++++++++ > > kernel/trace/trace_kprobe.c | 11 +++++++++++ > > 3 files changed, 34 insertions(+), 1 deletion(-) > > > > diff --git a/arch/Kconfig b/arch/Kconfig > > index cfc24ced16dd..e60ce984d095 100644 > > --- a/arch/Kconfig > > +++ b/arch/Kconfig > > @@ -52,8 +52,8 @@ config GENERIC_ENTRY > > > > config KPROBES > > bool "Kprobes" > > - depends on MODULES > > depends on HAVE_KPROBES > > + select MODULE_ALLOC > > select KALLSYMS > > select TASKS_RCU if PREEMPTION > > help > > diff --git a/kernel/kprobes.c b/kernel/kprobes.c > > index 9d9095e81792..194270e17d57 100644 > > --- a/kernel/kprobes.c > > +++ b/kernel/kprobes.c > > @@ -1556,8 +1556,12 @@ static bool is_cfi_preamble_symbol(unsigned long addr) > > str_has_prefix("__pfx_", symbuf); > > } > > > > +#if IS_ENABLED(CONFIG_MODULES) > > static int check_kprobe_address_safe(struct kprobe *p, > > struct module **probed_mod) > > +#else > > +static int check_kprobe_address_safe(struct kprobe *p) > > +#endif > > A bit ugly to have to change the prototype, why not just keep probed_mod > at all time ? > > When CONFIG_MODULES is not selected, __module_text_address() returns > NULL so it should work without that many #ifdefs. > > > { > > int ret; > > > > @@ -1580,6 +1584,7 @@ static int check_kprobe_address_safe(struct kprobe *p, > > goto out; > > } > > > > +#if IS_ENABLED(CONFIG_MODULES) > > /* Check if 'p' is probing a module. */ > > *probed_mod = __module_text_address((unsigned long) p->addr); > > if (*probed_mod) { > > @@ -1603,6 +1608,8 @@ static int check_kprobe_address_safe(struct kprobe *p, > > ret = -ENOENT; > > } > > } > > +#endif > > + > > out: > > preempt_enable(); > > jump_label_unlock(); > > @@ -1614,7 +1621,9 @@ int register_kprobe(struct kprobe *p) > > { > > int ret; > > struct kprobe *old_p; > > +#if IS_ENABLED(CONFIG_MODULES) > > struct module *probed_mod; > > +#endif > > kprobe_opcode_t *addr; > > bool on_func_entry; > > > > @@ -1633,7 +1642,11 @@ int register_kprobe(struct kprobe *p) > > p->nmissed = 0; > > INIT_LIST_HEAD(&p->list); > > > > +#if IS_ENABLED(CONFIG_MODULES) > > ret = check_kprobe_address_safe(p, &probed_mod); > > +#else > > + ret = check_kprobe_address_safe(p); > > +#endif > > if (ret) > > return ret; > > > > @@ -1676,8 +1689,10 @@ int register_kprobe(struct kprobe *p) > > out: > > mutex_unlock(&kprobe_mutex); > > > > +#if IS_ENABLED(CONFIG_MODULES) > > if (probed_mod) > > module_put(probed_mod); > > +#endif > > > > return ret; > > } > > @@ -2482,6 +2497,7 @@ int kprobe_add_area_blacklist(unsigned long start, unsigned long end) > > return 0; > > } > > > > +#if IS_ENABLED(CONFIG_MODULES) > > /* Remove all symbols in given area from kprobe blacklist */ > > static void kprobe_remove_area_blacklist(unsigned long start, unsigned long end) > > { > > @@ -2499,6 +2515,7 @@ static void kprobe_remove_ksym_blacklist(unsigned long entry) > > { > > kprobe_remove_area_blacklist(entry, entry + 1); > > } > > +#endif > > > > int __weak arch_kprobe_get_kallsym(unsigned int *symnum, unsigned long *value, > > char *type, char *sym) > > @@ -2564,6 +2581,7 @@ static int __init populate_kprobe_blacklist(unsigned long *start, > > return ret ? : arch_populate_kprobe_blacklist(); > > } > > > > +#if IS_ENABLED(CONFIG_MODULES) > > static void add_module_kprobe_blacklist(struct module *mod) > > { > > unsigned long start, end; > > @@ -2665,6 +2683,7 @@ static struct notifier_block kprobe_module_nb = { > > .notifier_call = kprobes_module_callback, > > .priority = 0 > > }; > > +#endif /* IS_ENABLED(CONFIG_MODULES) */ > > > > void kprobe_free_init_mem(void) > > { > > @@ -2724,8 +2743,11 @@ static int __init init_kprobes(void) > > err = arch_init_kprobes(); > > if (!err) > > err = register_die_notifier(&kprobe_exceptions_nb); > > + > > +#if IS_ENABLED(CONFIG_MODULES) > > if (!err) > > err = register_module_notifier(&kprobe_module_nb); > > +#endif > > > > kprobes_initialized = (err == 0); > > kprobe_sysctls_init(); > > diff --git a/kernel/trace/trace_kprobe.c b/kernel/trace/trace_kprobe.c > > index c4c6e0e0068b..dd4598f775b9 100644 > > --- a/kernel/trace/trace_kprobe.c > > +++ b/kernel/trace/trace_kprobe.c > > @@ -102,6 +102,7 @@ static nokprobe_inline bool trace_kprobe_has_gone(struct trace_kprobe *tk) > > return kprobe_gone(&tk->rp.kp); > > } > > > > +#if IS_ENABLED(CONFIG_MODULES) > > static nokprobe_inline bool trace_kprobe_within_module(struct trace_kprobe *tk, > > struct module *mod) > > { > > @@ -129,6 +130,12 @@ static nokprobe_inline bool trace_kprobe_module_exist(struct trace_kprobe *tk) > > > > return ret; > > } > > +#else > > +static nokprobe_inline bool trace_kprobe_module_exist(struct trace_kprobe *tk) > > +{ > > + return true; > > +} > > +#endif > > > > static bool trace_kprobe_is_busy(struct dyn_event *ev) > > { > > @@ -670,6 +677,7 @@ static int register_trace_kprobe(struct trace_kprobe *tk) > > return ret; > > } > > > > +#if IS_ENABLED(CONFIG_MODULES) > > /* Module notifier call back, checking event on the module */ > > static int trace_kprobe_module_callback(struct notifier_block *nb, > > unsigned long val, void *data) > > @@ -704,6 +712,7 @@ static struct notifier_block trace_kprobe_module_nb = { > > .notifier_call = trace_kprobe_module_callback, > > .priority = 1 /* Invoked after kprobe module callback */ > > }; > > +#endif /* IS_ENABLED(CONFIG_MODULES) */ > > > > static int count_symbols(void *data, unsigned long unused) > > { > > @@ -1897,8 +1906,10 @@ static __init int init_kprobe_trace_early(void) > > if (ret) > > return ret; > > > > +#if IS_ENABLED(CONFIG_MODULES) > > if (register_module_notifier(&trace_kprobe_module_nb)) > > return -EINVAL; > Why a #if here ? > > If CONFIG_MODULES is not selected, register_module_notifier() return > always 0. > > > +#endif > > > > return 0; > > } > > -- > > 2.43.0 > > > >
diff --git a/arch/Kconfig b/arch/Kconfig index cfc24ced16dd..e60ce984d095 100644 --- a/arch/Kconfig +++ b/arch/Kconfig @@ -52,8 +52,8 @@ config GENERIC_ENTRY config KPROBES bool "Kprobes" - depends on MODULES depends on HAVE_KPROBES + select MODULE_ALLOC select KALLSYMS select TASKS_RCU if PREEMPTION help diff --git a/kernel/kprobes.c b/kernel/kprobes.c index 9d9095e81792..194270e17d57 100644 --- a/kernel/kprobes.c +++ b/kernel/kprobes.c @@ -1556,8 +1556,12 @@ static bool is_cfi_preamble_symbol(unsigned long addr) str_has_prefix("__pfx_", symbuf); } +#if IS_ENABLED(CONFIG_MODULES) static int check_kprobe_address_safe(struct kprobe *p, struct module **probed_mod) +#else +static int check_kprobe_address_safe(struct kprobe *p) +#endif { int ret; @@ -1580,6 +1584,7 @@ static int check_kprobe_address_safe(struct kprobe *p, goto out; } +#if IS_ENABLED(CONFIG_MODULES) /* Check if 'p' is probing a module. */ *probed_mod = __module_text_address((unsigned long) p->addr); if (*probed_mod) { @@ -1603,6 +1608,8 @@ static int check_kprobe_address_safe(struct kprobe *p, ret = -ENOENT; } } +#endif + out: preempt_enable(); jump_label_unlock(); @@ -1614,7 +1621,9 @@ int register_kprobe(struct kprobe *p) { int ret; struct kprobe *old_p; +#if IS_ENABLED(CONFIG_MODULES) struct module *probed_mod; +#endif kprobe_opcode_t *addr; bool on_func_entry; @@ -1633,7 +1642,11 @@ int register_kprobe(struct kprobe *p) p->nmissed = 0; INIT_LIST_HEAD(&p->list); +#if IS_ENABLED(CONFIG_MODULES) ret = check_kprobe_address_safe(p, &probed_mod); +#else + ret = check_kprobe_address_safe(p); +#endif if (ret) return ret; @@ -1676,8 +1689,10 @@ int register_kprobe(struct kprobe *p) out: mutex_unlock(&kprobe_mutex); +#if IS_ENABLED(CONFIG_MODULES) if (probed_mod) module_put(probed_mod); +#endif return ret; } @@ -2482,6 +2497,7 @@ int kprobe_add_area_blacklist(unsigned long start, unsigned long end) return 0; } +#if IS_ENABLED(CONFIG_MODULES) /* Remove all symbols in given area from kprobe blacklist */ static void kprobe_remove_area_blacklist(unsigned long start, unsigned long end) { @@ -2499,6 +2515,7 @@ static void kprobe_remove_ksym_blacklist(unsigned long entry) { kprobe_remove_area_blacklist(entry, entry + 1); } +#endif int __weak arch_kprobe_get_kallsym(unsigned int *symnum, unsigned long *value, char *type, char *sym) @@ -2564,6 +2581,7 @@ static int __init populate_kprobe_blacklist(unsigned long *start, return ret ? : arch_populate_kprobe_blacklist(); } +#if IS_ENABLED(CONFIG_MODULES) static void add_module_kprobe_blacklist(struct module *mod) { unsigned long start, end; @@ -2665,6 +2683,7 @@ static struct notifier_block kprobe_module_nb = { .notifier_call = kprobes_module_callback, .priority = 0 }; +#endif /* IS_ENABLED(CONFIG_MODULES) */ void kprobe_free_init_mem(void) { @@ -2724,8 +2743,11 @@ static int __init init_kprobes(void) err = arch_init_kprobes(); if (!err) err = register_die_notifier(&kprobe_exceptions_nb); + +#if IS_ENABLED(CONFIG_MODULES) if (!err) err = register_module_notifier(&kprobe_module_nb); +#endif kprobes_initialized = (err == 0); kprobe_sysctls_init(); diff --git a/kernel/trace/trace_kprobe.c b/kernel/trace/trace_kprobe.c index c4c6e0e0068b..dd4598f775b9 100644 --- a/kernel/trace/trace_kprobe.c +++ b/kernel/trace/trace_kprobe.c @@ -102,6 +102,7 @@ static nokprobe_inline bool trace_kprobe_has_gone(struct trace_kprobe *tk) return kprobe_gone(&tk->rp.kp); } +#if IS_ENABLED(CONFIG_MODULES) static nokprobe_inline bool trace_kprobe_within_module(struct trace_kprobe *tk, struct module *mod) { @@ -129,6 +130,12 @@ static nokprobe_inline bool trace_kprobe_module_exist(struct trace_kprobe *tk) return ret; } +#else +static nokprobe_inline bool trace_kprobe_module_exist(struct trace_kprobe *tk) +{ + return true; +} +#endif static bool trace_kprobe_is_busy(struct dyn_event *ev) { @@ -670,6 +677,7 @@ static int register_trace_kprobe(struct trace_kprobe *tk) return ret; } +#if IS_ENABLED(CONFIG_MODULES) /* Module notifier call back, checking event on the module */ static int trace_kprobe_module_callback(struct notifier_block *nb, unsigned long val, void *data) @@ -704,6 +712,7 @@ static struct notifier_block trace_kprobe_module_nb = { .notifier_call = trace_kprobe_module_callback, .priority = 1 /* Invoked after kprobe module callback */ }; +#endif /* IS_ENABLED(CONFIG_MODULES) */ static int count_symbols(void *data, unsigned long unused) { @@ -1897,8 +1906,10 @@ static __init int init_kprobe_trace_early(void) if (ret) return ret; +#if IS_ENABLED(CONFIG_MODULES) if (register_module_notifier(&trace_kprobe_module_nb)) return -EINVAL; +#endif return 0; }
If something like this is merged down the road, it can go in at leisure once the module_alloc change is in: it's a one-way dependency. Signed-off-by: Calvin Owens <jcalvinowens@gmail.com> --- arch/Kconfig | 2 +- kernel/kprobes.c | 22 ++++++++++++++++++++++ kernel/trace/trace_kprobe.c | 11 +++++++++++ 3 files changed, 34 insertions(+), 1 deletion(-)