[PATCH v3 12/13] kprobes: remove dependency on CONFIG_MODULES
From: Mike Rapoport <rppt@kernel.org>
Date: 2023-09-18 07:33:28
Also in:
bpf, linux-arm-kernel, linux-mips, linux-mm, linux-modules, linux-riscv, linux-s390, linux-trace-kernel, lkml, loongarch, netdev, sparclinux
Subsystem:
kprobes, the rest, tracing · Maintainers:
Naveen N Rao, "David S. Miller", Masami Hiramatsu, Linus Torvalds, Steven Rostedt
From: "Mike Rapoport (IBM)" <rppt@kernel.org> 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) <rppt@kernel.org> --- arch/Kconfig | 2 +- kernel/kprobes.c | 43 +++++++++++++++++++++---------------- kernel/trace/trace_kprobe.c | 11 ++++++++++ 3 files changed, 37 insertions(+), 19 deletions(-)
diff --git a/arch/Kconfig b/arch/Kconfig
index 12d51495caec..c52a600b63ca 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/kernel/kprobes.c b/kernel/kprobes.c
index 0ccb4d2ec9a2..c95d0088f966 100644
--- a/kernel/kprobes.c
+++ b/kernel/kprobes.c@@ -1580,6 +1580,7 @@ static int check_kprobe_address_safe(struct kprobe *p, goto out; } +#ifdef CONFIG_MODULES /* Check if 'p' is probing a module. */ *probed_mod = __module_text_address((unsigned long) p->addr); if (*probed_mod) {
@@ -1603,6 +1604,8 @@ static int check_kprobe_address_safe(struct kprobe *p, ret = -ENOENT; } } +#endif + out: preempt_enable(); jump_label_unlock();
@@ -2495,24 +2498,6 @@ 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) {
@@ -2577,6 +2562,25 @@ 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;
@@ -2678,6 +2682,7 @@ static struct notifier_block kprobe_module_nb = { .notifier_call = kprobes_module_callback, .priority = 0 }; +#endif void kprobe_free_init_mem(void) {
@@ -2737,8 +2742,10 @@ static int __init init_kprobes(void) err = arch_init_kprobes(); if (!err) err = register_die_notifier(&kprobe_exceptions_nb); +#ifdef 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 3d7a180a8427..25a5293a80c0 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 +712,7 @@ static struct notifier_block trace_kprobe_module_nb = { .notifier_call = trace_kprobe_module_callback, .priority = 1 /* Invoked after kprobe module callback */ }; +#endif static int __trace_kprobe_create(int argc, const char *argv[]) {
@@ -1810,8 +1819,10 @@ static __init int init_kprobe_trace_early(void) if (ret) return ret; +#ifdef CONFIG_MODULES if (register_module_notifier(&trace_kprobe_module_nb)) return -EINVAL; +#endif return 0; }
--
2.39.2