From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 4609B2E642; Fri, 8 Mar 2024 02:46:08 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1709865968; cv=none; b=E+qEPuqHLMCEdoma/t6PFwyOdwx4dZZvKDVPa2QSanQtcFoA+sw1ZwsDbwDhrOr/194Ah9S36xxVgzTJ5PSAJvtJ+jqxzQuy7BLBT7ln2yM6tlmUUEBMkoR9McxpIcW4UolfLHSCR9cC8yfXd7b5QXJrqiw0BkcferTWSXA0fAo= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1709865968; c=relaxed/simple; bh=8xrRZwXZcCuvmbC8TREQJ90MQaawTnhPh+5bykKMT4s=; h=Date:From:To:Cc:Subject:Message-Id:In-Reply-To:References: Mime-Version:Content-Type; b=NLhw/vcfUPS5aKBLswON+rnKxEDnY38aKoDbWt+DKB19pUyo82zkGJMSaoVQzaOjNB3jiCsBz5YGtkgb/UHM6txgYZO5bN9OJnQITebKdt2VojKZnvspkRkyeU2RONHX9+YoUeDzjN7wxAFOHp3Elmcy2YCSEks8dgc6dXmZRFs= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=PoB4ofvK; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="PoB4ofvK" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 70C0BC43390; Fri, 8 Mar 2024 02:46:05 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1709865968; bh=8xrRZwXZcCuvmbC8TREQJ90MQaawTnhPh+5bykKMT4s=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=PoB4ofvK0pJw6o5nobGJf6x57aRoErEoJSsWC3MjNHbYAQy32GqJXAN56xAX5wcat lhB9/6UnCah6TSrrdaw0FBEcTKqxNNu4wmjfURezpuTkx7wAHCpxWb534ERHcqLeVN ME1grFJcV1ZedM3IiDpZoqUQEWbWwyZGvDpeityGO5zvJkdZz4oEtSOCvGCQ9d1qq8 lxj7eDm6IJwcol3JoDSgpc/WycAWn/lrm9D0rSfdWSh7HXZtSdONZ6PJIchllUYwGg v9wr3BI4mdWmG/T4NrGmguYtyylR6DwiFqXzyBhtjqseHmIzYRoCQ6yFiV0kNdxgY4 rJUPf4/5bw6Jw== Date: Fri, 8 Mar 2024 11:46:03 +0900 From: Masami Hiramatsu (Google) To: Calvin Owens Cc: Luis Chamberlain , Andrew Morton , Alexei Starovoitov , Steven Rostedt , Daniel Borkmann , Andrii Nakryiko , Naveen N Rao , Anil S Keshavamurthy , David S Miller , Thomas Gleixner , bpf@vger.kernel.org, linux-modules@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [RFC][PATCH 3/4] kprobes: Allow kprobes with CONFIG_MODULES=n Message-Id: <20240308114603.289720cf17ed75ba7bce8779@kernel.org> In-Reply-To: <2af01251ca21d79fa29092505d192f1f1b746cff.1709676663.git.jcalvinowens@gmail.com> References: <2af01251ca21d79fa29092505d192f1f1b746cff.1709676663.git.jcalvinowens@gmail.com> X-Mailer: Sylpheed 3.8.0beta1 (GTK+ 2.24.33; x86_64-pc-linux-gnu) Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit On Wed, 6 Mar 2024 12:05:10 -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 > --- > 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 > -- Masami Hiramatsu (Google)