From patchwork Fri Apr 26 08:28:53 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Mike Rapoport X-Patchwork-Id: 13644299 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 9400A1482E6; Fri, 26 Apr 2024 08:32:01 +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=1714120321; cv=none; b=WE1Plc8Ygng3VCU3HFVDJH/OSkUk/9bnp13aLyx+CMRHSb/AWlH9uZ6StrHfKWOQjBCnhSBFnCwv2A6gsTLJi4lTYFC+On79GWxFb4IRq3RnMqhFf9HWbO/KSihxg/w3OrqA0Yva5j6XaE52osfxyoAs4roIwwnzSOJ+NhRTb2I= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1714120321; c=relaxed/simple; bh=D/LgKkA0Gob427zNusjsii4Fgukj7DrmwMiYlEjdnlY=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=FPBO1y1UeNoexb3lUnlu6XE2S3wpXXLOd5JlCiSihauputbothDYAiwgcJv35/1fIJce24RAkq7UiySANvd90pgYiUX7VtLlJpv8i4GHwKaUJ2+9M2ggiryf37vsoPF1zpsVOsS7f8rOrLc0qlFdPEbkU48pKb3ZRO41nt35Qzg= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=NtDywaXn; 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="NtDywaXn" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 9AC87C113CD; Fri, 26 Apr 2024 08:31:50 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1714120321; bh=D/LgKkA0Gob427zNusjsii4Fgukj7DrmwMiYlEjdnlY=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=NtDywaXnqnWhuljILjD8vmTh9geXka1YAKmrSFvlc56Zd5ODWg+iM6Unoh+n3wcxI L4E0HsSEB5v/LHXXRsLUtO0SO7LTmy+BAA3wAxIIVnvtSteMFuA2N3i/4UpIdklune EzfCeM98t8Hc1qm9JZ+1FkFhN1OPt8udZCnF0Wvh3xAotBdjwQf97lT3sW1NeMNYoP 81DpiOWgN5sVjGNNODQSpRT/Lhjj+goH6mo+AYRgO1Kg7HDrhMX16dopMv0So1vXA8 dkFDq+I+68+VjdW3ccTkzktM4kS9aT3Iz/97vDr7gBlrvzvihqzr3gKlC/HdPVeUlA USa/X+rEkZMSg== From: Mike Rapoport To: linux-kernel@vger.kernel.org Cc: Alexandre Ghiti , Andrew Morton , =?utf-8?b?QmrDtnJuIFTDtnBlbA==?= , Catalin Marinas , Christophe Leroy , "David S. Miller" , Dinh Nguyen , Donald Dutile , Eric Chanudet , Heiko Carstens , Helge Deller , Huacai Chen , Kent Overstreet , Luis Chamberlain , Mark Rutland , Masami Hiramatsu , Michael Ellerman , Mike Rapoport , Nadav Amit , Palmer Dabbelt , Peter Zijlstra , Rick Edgecombe , Russell King , Sam Ravnborg , Song Liu , Steven Rostedt , Thomas Bogendoerfer , Thomas Gleixner , Will Deacon , bpf@vger.kernel.org, linux-arch@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-mips@vger.kernel.org, linux-mm@kvack.org, linux-modules@vger.kernel.org, linux-parisc@vger.kernel.org, linux-riscv@lists.infradead.org, linux-s390@vger.kernel.org, linux-trace-kernel@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, loongarch@lists.linux.dev, netdev@vger.kernel.org, sparclinux@vger.kernel.org, x86@kernel.org Subject: [PATCH v6 15/16] kprobes: remove dependency on CONFIG_MODULES Date: Fri, 26 Apr 2024 11:28:53 +0300 Message-ID: <20240426082854.7355-16-rppt@kernel.org> X-Mailer: git-send-email 2.43.0 In-Reply-To: <20240426082854.7355-1-rppt@kernel.org> References: <20240426082854.7355-1-rppt@kernel.org> Precedence: bulk X-Mailing-List: bpf@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 From: "Mike Rapoport (IBM)" kprobes depended on CONFIG_MODULES because it has to allocate memory for code. Since code allocations are now implemented with execmem, kprobes can be enabled in non-modular kernels. Add #ifdef CONFIG_MODULE guards for the code dealing with kprobes inside modules, make CONFIG_KPROBES select CONFIG_EXECMEM and drop the dependency of CONFIG_KPROBES on CONFIG_MODULES. Signed-off-by: Mike Rapoport (IBM) --- arch/Kconfig | 2 +- include/linux/module.h | 9 ++++++ kernel/kprobes.c | 55 +++++++++++++++++++++++-------------- kernel/trace/trace_kprobe.c | 20 +++++++++++++- 4 files changed, 63 insertions(+), 23 deletions(-) diff --git a/arch/Kconfig b/arch/Kconfig index 4fd0daa54e6c..caa459964f09 100644 --- a/arch/Kconfig +++ b/arch/Kconfig @@ -52,9 +52,9 @@ config GENERIC_ENTRY config KPROBES bool "Kprobes" - depends on MODULES depends on HAVE_KPROBES select KALLSYMS + select EXECMEM select TASKS_RCU if PREEMPTION help Kprobes allows you to trap at almost any kernel address and diff --git a/include/linux/module.h b/include/linux/module.h index 1153b0d99a80..ffa1c603163c 100644 --- a/include/linux/module.h +++ b/include/linux/module.h @@ -605,6 +605,11 @@ static inline bool module_is_live(struct module *mod) return mod->state != MODULE_STATE_GOING; } +static inline bool module_is_coming(struct module *mod) +{ + return mod->state == MODULE_STATE_COMING; +} + struct module *__module_text_address(unsigned long addr); struct module *__module_address(unsigned long addr); bool is_module_address(unsigned long addr); @@ -857,6 +862,10 @@ void *dereference_module_function_descriptor(struct module *mod, void *ptr) return ptr; } +static inline bool module_is_coming(struct module *mod) +{ + return false; +} #endif /* CONFIG_MODULES */ #ifdef CONFIG_SYSFS diff --git a/kernel/kprobes.c b/kernel/kprobes.c index ddd7cdc16edf..ca2c6cbd42d2 100644 --- a/kernel/kprobes.c +++ b/kernel/kprobes.c @@ -1588,7 +1588,7 @@ static int check_kprobe_address_safe(struct kprobe *p, } /* Get module refcount and reject __init functions for loaded modules. */ - if (*probed_mod) { + if (IS_ENABLED(CONFIG_MODULES) && *probed_mod) { /* * We must hold a refcount of the probed module while updating * its code to prohibit unexpected unloading. @@ -1603,12 +1603,13 @@ static int check_kprobe_address_safe(struct kprobe *p, * kprobes in there. */ if (within_module_init((unsigned long)p->addr, *probed_mod) && - (*probed_mod)->state != MODULE_STATE_COMING) { + !module_is_coming(*probed_mod)) { module_put(*probed_mod); *probed_mod = NULL; ret = -ENOENT; } } + out: preempt_enable(); jump_label_unlock(); @@ -2488,24 +2489,6 @@ int kprobe_add_area_blacklist(unsigned long start, unsigned long end) return 0; } -/* Remove all symbols in given area from kprobe blacklist */ -static void kprobe_remove_area_blacklist(unsigned long start, unsigned long end) -{ - struct kprobe_blacklist_entry *ent, *n; - - list_for_each_entry_safe(ent, n, &kprobe_blacklist, list) { - if (ent->start_addr < start || ent->start_addr >= end) - continue; - list_del(&ent->list); - kfree(ent); - } -} - -static void kprobe_remove_ksym_blacklist(unsigned long entry) -{ - kprobe_remove_area_blacklist(entry, entry + 1); -} - int __weak arch_kprobe_get_kallsym(unsigned int *symnum, unsigned long *value, char *type, char *sym) { @@ -2570,6 +2553,25 @@ static int __init populate_kprobe_blacklist(unsigned long *start, return ret ? : arch_populate_kprobe_blacklist(); } +#ifdef CONFIG_MODULES +/* Remove all symbols in given area from kprobe blacklist */ +static void kprobe_remove_area_blacklist(unsigned long start, unsigned long end) +{ + struct kprobe_blacklist_entry *ent, *n; + + list_for_each_entry_safe(ent, n, &kprobe_blacklist, list) { + if (ent->start_addr < start || ent->start_addr >= end) + continue; + list_del(&ent->list); + kfree(ent); + } +} + +static void kprobe_remove_ksym_blacklist(unsigned long entry) +{ + kprobe_remove_area_blacklist(entry, entry + 1); +} + static void add_module_kprobe_blacklist(struct module *mod) { unsigned long start, end; @@ -2672,6 +2674,17 @@ static struct notifier_block kprobe_module_nb = { .priority = 0 }; +static int kprobe_register_module_notifier(void) +{ + return register_module_notifier(&kprobe_module_nb); +} +#else +static int kprobe_register_module_notifier(void) +{ + return 0; +} +#endif /* CONFIG_MODULES */ + void kprobe_free_init_mem(void) { void *start = (void *)(&__init_begin); @@ -2731,7 +2744,7 @@ static int __init init_kprobes(void) if (!err) err = register_die_notifier(&kprobe_exceptions_nb); if (!err) - err = register_module_notifier(&kprobe_module_nb); + err = kprobe_register_module_notifier(); kprobes_initialized = (err == 0); kprobe_sysctls_init(); diff --git a/kernel/trace/trace_kprobe.c b/kernel/trace/trace_kprobe.c index 14099cc17fc9..2cb2a3951b4f 100644 --- a/kernel/trace/trace_kprobe.c +++ b/kernel/trace/trace_kprobe.c @@ -111,6 +111,7 @@ static nokprobe_inline bool trace_kprobe_within_module(struct trace_kprobe *tk, return strncmp(module_name(mod), name, len) == 0 && name[len] == ':'; } +#ifdef CONFIG_MODULES static nokprobe_inline bool trace_kprobe_module_exist(struct trace_kprobe *tk) { char *p; @@ -129,6 +130,12 @@ static nokprobe_inline bool trace_kprobe_module_exist(struct trace_kprobe *tk) return ret; } +#else +static inline bool trace_kprobe_module_exist(struct trace_kprobe *tk) +{ + return false; +} +#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; } +#ifdef 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 +712,16 @@ static struct notifier_block trace_kprobe_module_nb = { .notifier_call = trace_kprobe_module_callback, .priority = 1 /* Invoked after kprobe module callback */ }; +static int trace_kprobe_register_module_notifier(void) +{ + return register_module_notifier(&trace_kprobe_module_nb); +} +#else +static int trace_kprobe_register_module_notifier(void) +{ + return 0; +} +#endif /* CONFIG_MODULES */ static int count_symbols(void *data, unsigned long unused) { @@ -1933,7 +1951,7 @@ static __init int init_kprobe_trace_early(void) if (ret) return ret; - if (register_module_notifier(&trace_kprobe_module_nb)) + if (trace_kprobe_register_module_notifier()) return -EINVAL; return 0;