diff options
Diffstat (limited to 'kernel')
| -rw-r--r-- | kernel/bpf/Kconfig | 2 | ||||
| -rw-r--r-- | kernel/bpf/core.c | 6 | ||||
| -rw-r--r-- | kernel/kprobes.c | 63 | ||||
| -rw-r--r-- | kernel/module/Kconfig | 3 | ||||
| -rw-r--r-- | kernel/module/kallsyms.c | 2 | ||||
| -rw-r--r-- | kernel/module/main.c | 105 | ||||
| -rw-r--r-- | kernel/trace/trace_kprobe.c | 20 |
7 files changed, 112 insertions, 89 deletions
diff --git a/kernel/bpf/Kconfig b/kernel/bpf/Kconfig index 4100df44c665..17067dcb4386 100644 --- a/kernel/bpf/Kconfig +++ b/kernel/bpf/Kconfig @@ -43,7 +43,7 @@ config BPF_JIT bool "Enable BPF Just In Time compiler" depends on BPF depends on HAVE_CBPF_JIT || HAVE_EBPF_JIT - depends on MODULES + select EXECMEM help BPF programs are normally handled by a BPF interpreter. This option allows the kernel to generate native code when a program is loaded diff --git a/kernel/bpf/core.c b/kernel/bpf/core.c index 733fca2634b7..1a6c3faa6e4a 100644 --- a/kernel/bpf/core.c +++ b/kernel/bpf/core.c @@ -22,7 +22,6 @@ #include <linux/skbuff.h> #include <linux/vmalloc.h> #include <linux/random.h> -#include <linux/moduleloader.h> #include <linux/bpf.h> #include <linux/btf.h> #include <linux/objtool.h> @@ -38,6 +37,7 @@ #include <linux/nospec.h> #include <linux/bpf_mem_alloc.h> #include <linux/memcontrol.h> +#include <linux/execmem.h> #include <asm/barrier.h> #include <asm/unaligned.h> @@ -1065,12 +1065,12 @@ void bpf_jit_uncharge_modmem(u32 size) void *__weak bpf_jit_alloc_exec(unsigned long size) { - return module_alloc(size); + return execmem_alloc(EXECMEM_BPF, size); } void __weak bpf_jit_free_exec(void *addr) { - module_memfree(addr); + execmem_free(addr); } struct bpf_binary_header * diff --git a/kernel/kprobes.c b/kernel/kprobes.c index 65adc815fc6e..ca2c6cbd42d2 100644 --- a/kernel/kprobes.c +++ b/kernel/kprobes.c @@ -26,7 +26,6 @@ #include <linux/slab.h> #include <linux/stddef.h> #include <linux/export.h> -#include <linux/moduleloader.h> #include <linux/kallsyms.h> #include <linux/freezer.h> #include <linux/seq_file.h> @@ -39,6 +38,7 @@ #include <linux/jump_label.h> #include <linux/static_call.h> #include <linux/perf_event.h> +#include <linux/execmem.h> #include <asm/sections.h> #include <asm/cacheflush.h> @@ -113,17 +113,17 @@ enum kprobe_slot_state { void __weak *alloc_insn_page(void) { /* - * Use module_alloc() so this page is within +/- 2GB of where the + * Use execmem_alloc() so this page is within +/- 2GB of where the * kernel image and loaded module images reside. This is required * for most of the architectures. * (e.g. x86-64 needs this to handle the %rip-relative fixups.) */ - return module_alloc(PAGE_SIZE); + return execmem_alloc(EXECMEM_KPROBES, PAGE_SIZE); } static void free_insn_page(void *page) { - module_memfree(page); + execmem_free(page); } struct kprobe_insn_cache kprobe_insn_slots = { @@ -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/module/Kconfig b/kernel/module/Kconfig index f3e0329337f6..4047b6d48255 100644 --- a/kernel/module/Kconfig +++ b/kernel/module/Kconfig @@ -2,6 +2,7 @@ menuconfig MODULES bool "Enable loadable module support" modules + select EXECMEM help Kernel modules are small pieces of compiled code which can be inserted in the running kernel, rather than being @@ -392,7 +393,7 @@ config UNUSED_KSYMS_WHITELIST exported at all times, even in absence of in-tree users. The value to set here is the path to a text file containing the list of symbols, one per line. The path can be absolute, or relative to the kernel - source tree. + source or obj tree. config MODULES_TREE_LOOKUP def_bool y diff --git a/kernel/module/kallsyms.c b/kernel/module/kallsyms.c index ef73ae7c8909..62fb57bb9f16 100644 --- a/kernel/module/kallsyms.c +++ b/kernel/module/kallsyms.c @@ -348,7 +348,7 @@ const char *module_address_lookup(unsigned long addr, } /* Make a copy in here where it's safe */ if (ret) { - strncpy(namebuf, ret, KSYM_NAME_LEN - 1); + strscpy(namebuf, ret, KSYM_NAME_LEN); ret = namebuf; } preempt_enable(); diff --git a/kernel/module/main.c b/kernel/module/main.c index e1e8a7a9d6c1..91e185607d4b 100644 --- a/kernel/module/main.c +++ b/kernel/module/main.c @@ -57,6 +57,7 @@ #include <linux/audit.h> #include <linux/cfi.h> #include <linux/debugfs.h> +#include <linux/execmem.h> #include <uapi/linux/module.h> #include "internal.h" @@ -1179,16 +1180,6 @@ resolve_symbol_wait(struct module *mod, return ksym; } -void __weak module_memfree(void *module_region) -{ - /* - * This memory may be RO, and freeing RO memory in an interrupt is not - * supported by vmalloc. - */ - WARN_ON(in_interrupt()); - vfree(module_region); -} - void __weak module_arch_cleanup(struct module *mod) { } @@ -1197,25 +1188,47 @@ void __weak module_arch_freeing_init(struct module *mod) { } -static bool mod_mem_use_vmalloc(enum mod_mem_type type) +static int module_memory_alloc(struct module *mod, enum mod_mem_type type) { - return IS_ENABLED(CONFIG_ARCH_WANTS_MODULES_DATA_IN_VMALLOC) && - mod_mem_type_is_core_data(type); -} + unsigned int size = PAGE_ALIGN(mod->mem[type].size); + enum execmem_type execmem_type; + void *ptr; -static void *module_memory_alloc(unsigned int size, enum mod_mem_type type) -{ - if (mod_mem_use_vmalloc(type)) - return vzalloc(size); - return module_alloc(size); + mod->mem[type].size = size; + + if (mod_mem_type_is_data(type)) + execmem_type = EXECMEM_MODULE_DATA; + else + execmem_type = EXECMEM_MODULE_TEXT; + + ptr = execmem_alloc(execmem_type, size); + if (!ptr) + return -ENOMEM; + + /* + * The pointer to these blocks of memory are stored on the module + * structure and we keep that around so long as the module is + * around. We only free that memory when we unload the module. + * Just mark them as not being a leak then. The .init* ELF + * sections *do* get freed after boot so we *could* treat them + * slightly differently with kmemleak_ignore() and only grey + * them out as they work as typical memory allocations which + * *do* eventually get freed, but let's just keep things simple + * and avoid *any* false positives. + */ + kmemleak_not_leak(ptr); + + memset(ptr, 0, size); + mod->mem[type].base = ptr; + + return 0; } -static void module_memory_free(void *ptr, enum mod_mem_type type) +static void module_memory_free(struct module *mod, enum mod_mem_type type) { - if (mod_mem_use_vmalloc(type)) - vfree(ptr); - else - module_memfree(ptr); + void *ptr = mod->mem[type].base; + + execmem_free(ptr); } static void free_mod_mem(struct module *mod) @@ -1229,12 +1242,12 @@ static void free_mod_mem(struct module *mod) /* Free lock-classes; relies on the preceding sync_rcu(). */ lockdep_free_key_range(mod_mem->base, mod_mem->size); if (mod_mem->size) - module_memory_free(mod_mem->base, type); + module_memory_free(mod, type); } /* MOD_DATA hosts mod, so free it at last */ lockdep_free_key_range(mod->mem[MOD_DATA].base, mod->mem[MOD_DATA].size); - module_memory_free(mod->mem[MOD_DATA].base, MOD_DATA); + module_memory_free(mod, MOD_DATA); } /* Free a module, remove from lists, etc. */ @@ -1610,13 +1623,6 @@ static void free_modinfo(struct module *mod) } } -void * __weak module_alloc(unsigned long size) -{ - return __vmalloc_node_range(size, 1, VMALLOC_START, VMALLOC_END, - GFP_KERNEL, PAGE_KERNEL_EXEC, VM_FLUSH_RESET_PERMS, - NUMA_NO_NODE, __builtin_return_address(0)); -} - bool __weak module_init_section(const char *name) { return strstarts(name, ".init"); @@ -2225,7 +2231,6 @@ static int find_module_sections(struct module *mod, struct load_info *info) static int move_module(struct module *mod, struct load_info *info) { int i; - void *ptr; enum mod_mem_type t = 0; int ret = -ENOMEM; @@ -2234,26 +2239,12 @@ static int move_module(struct module *mod, struct load_info *info) mod->mem[type].base = NULL; continue; } - mod->mem[type].size = PAGE_ALIGN(mod->mem[type].size); - ptr = module_memory_alloc(mod->mem[type].size, type); - /* - * The pointer to these blocks of memory are stored on the module - * structure and we keep that around so long as the module is - * around. We only free that memory when we unload the module. - * Just mark them as not being a leak then. The .init* ELF - * sections *do* get freed after boot so we *could* treat them - * slightly differently with kmemleak_ignore() and only grey - * them out as they work as typical memory allocations which - * *do* eventually get freed, but let's just keep things simple - * and avoid *any* false positives. - */ - kmemleak_not_leak(ptr); - if (!ptr) { + + ret = module_memory_alloc(mod, type); + if (ret) { t = type; goto out_enomem; } - memset(ptr, 0, mod->mem[type].size); - mod->mem[type].base = ptr; } /* Transfer each section which specifies SHF_ALLOC */ @@ -2296,7 +2287,7 @@ static int move_module(struct module *mod, struct load_info *info) return 0; out_enomem: for (t--; t >= 0; t--) - module_memory_free(mod->mem[t].base, t); + module_memory_free(mod, t); return ret; } @@ -2482,9 +2473,9 @@ static void do_free_init(struct work_struct *w) llist_for_each_safe(pos, n, list) { initfree = container_of(pos, struct mod_initfree, node); - module_memfree(initfree->init_text); - module_memfree(initfree->init_data); - module_memfree(initfree->init_rodata); + execmem_free(initfree->init_text); + execmem_free(initfree->init_data); + execmem_free(initfree->init_rodata); kfree(initfree); } } @@ -2594,10 +2585,10 @@ static noinline int do_init_module(struct module *mod) * We want to free module_init, but be aware that kallsyms may be * walking this with preempt disabled. In all the failure paths, we * call synchronize_rcu(), but we don't want to slow down the success - * path. module_memfree() cannot be called in an interrupt, so do the + * path. execmem_free() cannot be called in an interrupt, so do the * work and call synchronize_rcu() in a work queue. * - * Note that module_alloc() on most architectures creates W+X page + * Note that execmem_alloc() on most architectures creates W+X page * mappings which won't be cleaned up until do_free_init() runs. Any * code such as mark_rodata_ro() which depends on those mappings to * be cleaned up needs to sync with the queued work by invoking 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 @@ end: 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; |