diff options
| -rw-r--r-- | include/linux/module.h | 9 | ||||
| -rw-r--r-- | kernel/module/kallsyms.c | 2 | ||||
| -rw-r--r-- | kernel/trace/bpf_trace.c | 98 | ||||
| -rw-r--r-- | kernel/trace/ftrace.c | 16 | ||||
| -rw-r--r-- | tools/testing/selftests/bpf/bpf_testmod/bpf_testmod.c | 24 | ||||
| -rw-r--r-- | tools/testing/selftests/bpf/prog_tests/kprobe_multi_testmod_test.c | 89 | ||||
| -rw-r--r-- | tools/testing/selftests/bpf/prog_tests/module_attach.c | 7 | ||||
| -rw-r--r-- | tools/testing/selftests/bpf/progs/kprobe_multi.c | 50 | ||||
| -rw-r--r-- | tools/testing/selftests/bpf/progs/test_module_attach.c | 6 | ||||
| -rw-r--r-- | tools/testing/selftests/bpf/trace_helpers.c | 20 | ||||
| -rw-r--r-- | tools/testing/selftests/bpf/trace_helpers.h | 2 |
11 files changed, 306 insertions, 17 deletions
diff --git a/include/linux/module.h b/include/linux/module.h index ec61fb53979a..35876e89eb93 100644 --- a/include/linux/module.h +++ b/include/linux/module.h @@ -879,8 +879,17 @@ static inline bool module_sig_ok(struct module *module) } #endif /* CONFIG_MODULE_SIG */ +#if defined(CONFIG_MODULES) && defined(CONFIG_KALLSYMS) int module_kallsyms_on_each_symbol(int (*fn)(void *, const char *, struct module *, unsigned long), void *data); +#else +static inline int module_kallsyms_on_each_symbol(int (*fn)(void *, const char *, + struct module *, unsigned long), + void *data) +{ + return -EOPNOTSUPP; +} +#endif /* CONFIG_MODULES && CONFIG_KALLSYMS */ #endif /* _LINUX_MODULE_H */ diff --git a/kernel/module/kallsyms.c b/kernel/module/kallsyms.c index f5c5c9175333..4523f99b0358 100644 --- a/kernel/module/kallsyms.c +++ b/kernel/module/kallsyms.c @@ -494,7 +494,6 @@ unsigned long module_kallsyms_lookup_name(const char *name) return ret; } -#ifdef CONFIG_LIVEPATCH int module_kallsyms_on_each_symbol(int (*fn)(void *, const char *, struct module *, unsigned long), void *data) @@ -531,4 +530,3 @@ out: mutex_unlock(&module_mutex); return ret; } -#endif /* CONFIG_LIVEPATCH */ diff --git a/kernel/trace/bpf_trace.c b/kernel/trace/bpf_trace.c index 49fb9ec8366d..2460e38f75ff 100644 --- a/kernel/trace/bpf_trace.c +++ b/kernel/trace/bpf_trace.c @@ -2450,6 +2450,8 @@ struct bpf_kprobe_multi_link { unsigned long *addrs; u64 *cookies; u32 cnt; + u32 mods_cnt; + struct module **mods; }; struct bpf_kprobe_multi_run_ctx { @@ -2505,6 +2507,14 @@ error: return err; } +static void kprobe_multi_put_modules(struct module **mods, u32 cnt) +{ + u32 i; + + for (i = 0; i < cnt; i++) + module_put(mods[i]); +} + static void free_user_syms(struct user_syms *us) { kvfree(us->syms); @@ -2517,6 +2527,7 @@ static void bpf_kprobe_multi_link_release(struct bpf_link *link) kmulti_link = container_of(link, struct bpf_kprobe_multi_link, link); unregister_fprobe(&kmulti_link->fp); + kprobe_multi_put_modules(kmulti_link->mods, kmulti_link->mods_cnt); } static void bpf_kprobe_multi_link_dealloc(struct bpf_link *link) @@ -2526,6 +2537,7 @@ static void bpf_kprobe_multi_link_dealloc(struct bpf_link *link) kmulti_link = container_of(link, struct bpf_kprobe_multi_link, link); kvfree(kmulti_link->addrs); kvfree(kmulti_link->cookies); + kfree(kmulti_link->mods); kfree(kmulti_link); } @@ -2548,7 +2560,7 @@ static void bpf_kprobe_multi_cookie_swap(void *a, void *b, int size, const void swap(*cookie_a, *cookie_b); } -static int __bpf_kprobe_multi_cookie_cmp(const void *a, const void *b) +static int bpf_kprobe_multi_addrs_cmp(const void *a, const void *b) { const unsigned long *addr_a = a, *addr_b = b; @@ -2559,7 +2571,7 @@ static int __bpf_kprobe_multi_cookie_cmp(const void *a, const void *b) static int bpf_kprobe_multi_cookie_cmp(const void *a, const void *b, const void *priv) { - return __bpf_kprobe_multi_cookie_cmp(a, b); + return bpf_kprobe_multi_addrs_cmp(a, b); } static u64 bpf_kprobe_multi_cookie(struct bpf_run_ctx *ctx) @@ -2577,7 +2589,7 @@ static u64 bpf_kprobe_multi_cookie(struct bpf_run_ctx *ctx) return 0; entry_ip = run_ctx->entry_ip; addr = bsearch(&entry_ip, link->addrs, link->cnt, sizeof(entry_ip), - __bpf_kprobe_multi_cookie_cmp); + bpf_kprobe_multi_addrs_cmp); if (!addr) return 0; cookie = link->cookies + (addr - link->addrs); @@ -2661,6 +2673,71 @@ static void symbols_swap_r(void *a, void *b, int size, const void *priv) } } +struct module_addr_args { + unsigned long *addrs; + u32 addrs_cnt; + struct module **mods; + int mods_cnt; + int mods_cap; +}; + +static int module_callback(void *data, const char *name, + struct module *mod, unsigned long addr) +{ + struct module_addr_args *args = data; + struct module **mods; + + /* We iterate all modules symbols and for each we: + * - search for it in provided addresses array + * - if found we check if we already have the module pointer stored + * (we iterate modules sequentially, so we can check just the last + * module pointer) + * - take module reference and store it + */ + if (!bsearch(&addr, args->addrs, args->addrs_cnt, sizeof(addr), + bpf_kprobe_multi_addrs_cmp)) + return 0; + + if (args->mods && args->mods[args->mods_cnt - 1] == mod) + return 0; + + if (args->mods_cnt == args->mods_cap) { + args->mods_cap = max(16, args->mods_cap * 3 / 2); + mods = krealloc_array(args->mods, args->mods_cap, sizeof(*mods), GFP_KERNEL); + if (!mods) + return -ENOMEM; + args->mods = mods; + } + + if (!try_module_get(mod)) + return -EINVAL; + + args->mods[args->mods_cnt] = mod; + args->mods_cnt++; + return 0; +} + +static int get_modules_for_addrs(struct module ***mods, unsigned long *addrs, u32 addrs_cnt) +{ + struct module_addr_args args = { + .addrs = addrs, + .addrs_cnt = addrs_cnt, + }; + int err; + + /* We return either err < 0 in case of error, ... */ + err = module_kallsyms_on_each_symbol(module_callback, &args); + if (err) { + kprobe_multi_put_modules(args.mods, args.mods_cnt); + kfree(args.mods); + return err; + } + + /* or number of modules found if everything is ok. */ + *mods = args.mods; + return args.mods_cnt; +} + int bpf_kprobe_multi_link_attach(const union bpf_attr *attr, struct bpf_prog *prog) { struct bpf_kprobe_multi_link *link = NULL; @@ -2771,10 +2848,25 @@ int bpf_kprobe_multi_link_attach(const union bpf_attr *attr, struct bpf_prog *pr bpf_kprobe_multi_cookie_cmp, bpf_kprobe_multi_cookie_swap, link); + } else { + /* + * We need to sort addrs array even if there are no cookies + * provided, to allow bsearch in get_modules_for_addrs. + */ + sort(addrs, cnt, sizeof(*addrs), + bpf_kprobe_multi_addrs_cmp, NULL); + } + + err = get_modules_for_addrs(&link->mods, addrs, cnt); + if (err < 0) { + bpf_link_cleanup(&link_primer); + return err; } + link->mods_cnt = err; err = register_fprobe_ips(&link->fp, addrs, cnt); if (err) { + kprobe_multi_put_modules(link->mods, link->mods_cnt); bpf_link_cleanup(&link_primer); return err; } diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c index fbf2543111c0..72de9009a6a0 100644 --- a/kernel/trace/ftrace.c +++ b/kernel/trace/ftrace.c @@ -8267,6 +8267,10 @@ struct kallsyms_data { size_t found; }; +/* This function gets called for all kernel and module symbols + * and returns 1 in case we resolved all the requested symbols, + * 0 otherwise. + */ static int kallsyms_callback(void *data, const char *name, struct module *mod, unsigned long addr) { @@ -8309,17 +8313,19 @@ static int kallsyms_callback(void *data, const char *name, int ftrace_lookup_symbols(const char **sorted_syms, size_t cnt, unsigned long *addrs) { struct kallsyms_data args; - int err; + int found_all; memset(addrs, 0, sizeof(*addrs) * cnt); args.addrs = addrs; args.syms = sorted_syms; args.cnt = cnt; args.found = 0; - err = kallsyms_on_each_symbol(kallsyms_callback, &args); - if (err < 0) - return err; - return args.found == args.cnt ? 0 : -ESRCH; + + found_all = kallsyms_on_each_symbol(kallsyms_callback, &args); + if (found_all) + return 0; + found_all = module_kallsyms_on_each_symbol(kallsyms_callback, &args); + return found_all ? 0 : -ESRCH; } #ifdef CONFIG_SYSCTL diff --git a/tools/testing/selftests/bpf/bpf_testmod/bpf_testmod.c b/tools/testing/selftests/bpf/bpf_testmod/bpf_testmod.c index a6021d6117b5..5085fea3cac5 100644 --- a/tools/testing/selftests/bpf/bpf_testmod/bpf_testmod.c +++ b/tools/testing/selftests/bpf/bpf_testmod/bpf_testmod.c @@ -128,6 +128,23 @@ __weak noinline struct file *bpf_testmod_return_ptr(int arg) } } +noinline int bpf_testmod_fentry_test1(int a) +{ + return a + 1; +} + +noinline int bpf_testmod_fentry_test2(int a, u64 b) +{ + return a + b; +} + +noinline int bpf_testmod_fentry_test3(char a, int b, u64 c) +{ + return a + b + c; +} + +int bpf_testmod_fentry_ok; + noinline ssize_t bpf_testmod_test_read(struct file *file, struct kobject *kobj, struct bin_attribute *bin_attr, @@ -167,6 +184,13 @@ bpf_testmod_test_read(struct file *file, struct kobject *kobj, return snprintf(buf, len, "%d\n", writable.val); } + if (bpf_testmod_fentry_test1(1) != 2 || + bpf_testmod_fentry_test2(2, 3) != 5 || + bpf_testmod_fentry_test3(4, 5, 6) != 15) + goto out; + + bpf_testmod_fentry_ok = 1; +out: return -EIO; /* always fail */ } EXPORT_SYMBOL(bpf_testmod_test_read); diff --git a/tools/testing/selftests/bpf/prog_tests/kprobe_multi_testmod_test.c b/tools/testing/selftests/bpf/prog_tests/kprobe_multi_testmod_test.c new file mode 100644 index 000000000000..1fbe7e4ac00a --- /dev/null +++ b/tools/testing/selftests/bpf/prog_tests/kprobe_multi_testmod_test.c @@ -0,0 +1,89 @@ +// SPDX-License-Identifier: GPL-2.0 +#include <test_progs.h> +#include "kprobe_multi.skel.h" +#include "trace_helpers.h" +#include "bpf/libbpf_internal.h" + +static void kprobe_multi_testmod_check(struct kprobe_multi *skel) +{ + ASSERT_EQ(skel->bss->kprobe_testmod_test1_result, 1, "kprobe_test1_result"); + ASSERT_EQ(skel->bss->kprobe_testmod_test2_result, 1, "kprobe_test2_result"); + ASSERT_EQ(skel->bss->kprobe_testmod_test3_result, 1, "kprobe_test3_result"); + + ASSERT_EQ(skel->bss->kretprobe_testmod_test1_result, 1, "kretprobe_test1_result"); + ASSERT_EQ(skel->bss->kretprobe_testmod_test2_result, 1, "kretprobe_test2_result"); + ASSERT_EQ(skel->bss->kretprobe_testmod_test3_result, 1, "kretprobe_test3_result"); +} + +static void test_testmod_attach_api(struct bpf_kprobe_multi_opts *opts) +{ + struct kprobe_multi *skel = NULL; + + skel = kprobe_multi__open_and_load(); + if (!ASSERT_OK_PTR(skel, "fentry_raw_skel_load")) + return; + + skel->bss->pid = getpid(); + + skel->links.test_kprobe_testmod = bpf_program__attach_kprobe_multi_opts( + skel->progs.test_kprobe_testmod, + NULL, opts); + if (!skel->links.test_kprobe_testmod) + goto cleanup; + + opts->retprobe = true; + skel->links.test_kretprobe_testmod = bpf_program__attach_kprobe_multi_opts( + skel->progs.test_kretprobe_testmod, + NULL, opts); + if (!skel->links.test_kretprobe_testmod) + goto cleanup; + + ASSERT_OK(trigger_module_test_read(1), "trigger_read"); + kprobe_multi_testmod_check(skel); + +cleanup: + kprobe_multi__destroy(skel); +} + +static void test_testmod_attach_api_addrs(void) +{ + LIBBPF_OPTS(bpf_kprobe_multi_opts, opts); + unsigned long long addrs[3]; + + addrs[0] = ksym_get_addr("bpf_testmod_fentry_test1"); + ASSERT_NEQ(addrs[0], 0, "ksym_get_addr"); + addrs[1] = ksym_get_addr("bpf_testmod_fentry_test2"); + ASSERT_NEQ(addrs[1], 0, "ksym_get_addr"); + addrs[2] = ksym_get_addr("bpf_testmod_fentry_test3"); + ASSERT_NEQ(addrs[2], 0, "ksym_get_addr"); + + opts.addrs = (const unsigned long *) addrs; + opts.cnt = ARRAY_SIZE(addrs); + + test_testmod_attach_api(&opts); +} + +static void test_testmod_attach_api_syms(void) +{ + LIBBPF_OPTS(bpf_kprobe_multi_opts, opts); + const char *syms[3] = { + "bpf_testmod_fentry_test1", + "bpf_testmod_fentry_test2", + "bpf_testmod_fentry_test3", + }; + + opts.syms = syms; + opts.cnt = ARRAY_SIZE(syms); + test_testmod_attach_api(&opts); +} + +void serial_test_kprobe_multi_testmod_test(void) +{ + if (!ASSERT_OK(load_kallsyms_refresh(), "load_kallsyms_refresh")) + return; + + if (test__start_subtest("testmod_attach_api_syms")) + test_testmod_attach_api_syms(); + if (test__start_subtest("testmod_attach_api_addrs")) + test_testmod_attach_api_addrs(); +} diff --git a/tools/testing/selftests/bpf/prog_tests/module_attach.c b/tools/testing/selftests/bpf/prog_tests/module_attach.c index 6d0e50dcf47c..7fc01ff490db 100644 --- a/tools/testing/selftests/bpf/prog_tests/module_attach.c +++ b/tools/testing/selftests/bpf/prog_tests/module_attach.c @@ -103,6 +103,13 @@ void test_module_attach(void) ASSERT_ERR(delete_module("bpf_testmod", 0), "delete_module"); bpf_link__destroy(link); + link = bpf_program__attach(skel->progs.kprobe_multi); + if (!ASSERT_OK_PTR(link, "attach_kprobe_multi")) + goto cleanup; + + ASSERT_ERR(delete_module("bpf_testmod", 0), "delete_module"); + bpf_link__destroy(link); + cleanup: test_module_attach__destroy(skel); } diff --git a/tools/testing/selftests/bpf/progs/kprobe_multi.c b/tools/testing/selftests/bpf/progs/kprobe_multi.c index 98c3399e15c0..9e1ca8e34913 100644 --- a/tools/testing/selftests/bpf/progs/kprobe_multi.c +++ b/tools/testing/selftests/bpf/progs/kprobe_multi.c @@ -110,3 +110,53 @@ int test_kretprobe_manual(struct pt_regs *ctx) kprobe_multi_check(ctx, true); return 0; } + +extern const void bpf_testmod_fentry_test1 __ksym; +extern const void bpf_testmod_fentry_test2 __ksym; +extern const void bpf_testmod_fentry_test3 __ksym; + +__u64 kprobe_testmod_test1_result = 0; +__u64 kprobe_testmod_test2_result = 0; +__u64 kprobe_testmod_test3_result = 0; + +__u64 kretprobe_testmod_test1_result = 0; +__u64 kretprobe_testmod_test2_result = 0; +__u64 kretprobe_testmod_test3_result = 0; + +static void kprobe_multi_testmod_check(void *ctx, bool is_return) +{ + if (bpf_get_current_pid_tgid() >> 32 != pid) + return; + + __u64 addr = bpf_get_func_ip(ctx); + + if (is_return) { + if ((const void *) addr == &bpf_testmod_fentry_test1) + kretprobe_testmod_test1_result = 1; + if ((const void *) addr == &bpf_testmod_fentry_test2) + kretprobe_testmod_test2_result = 1; + if ((const void *) addr == &bpf_testmod_fentry_test3) + kretprobe_testmod_test3_result = 1; + } else { + if ((const void *) addr == &bpf_testmod_fentry_test1) + kprobe_testmod_test1_result = 1; + if ((const void *) addr == &bpf_testmod_fentry_test2) + kprobe_testmod_test2_result = 1; + if ((const void *) addr == &bpf_testmod_fentry_test3) + kprobe_testmod_test3_result = 1; + } +} + +SEC("kprobe.multi") +int test_kprobe_testmod(struct pt_regs *ctx) +{ + kprobe_multi_testmod_check(ctx, false); + return 0; +} + +SEC("kretprobe.multi") +int test_kretprobe_testmod(struct pt_regs *ctx) +{ + kprobe_multi_testmod_check(ctx, true); + return 0; +} diff --git a/tools/testing/selftests/bpf/progs/test_module_attach.c b/tools/testing/selftests/bpf/progs/test_module_attach.c index 08628afedb77..8a1b50f3a002 100644 --- a/tools/testing/selftests/bpf/progs/test_module_attach.c +++ b/tools/testing/selftests/bpf/progs/test_module_attach.c @@ -110,4 +110,10 @@ int BPF_PROG(handle_fmod_ret, return 0; /* don't override the exit code */ } +SEC("kprobe.multi/bpf_testmod_test_read") +int BPF_PROG(kprobe_multi) +{ + return 0; +} + char _license[] SEC("license") = "GPL"; diff --git a/tools/testing/selftests/bpf/trace_helpers.c b/tools/testing/selftests/bpf/trace_helpers.c index 9c4be2cdb21a..09a16a77bae4 100644 --- a/tools/testing/selftests/bpf/trace_helpers.c +++ b/tools/testing/selftests/bpf/trace_helpers.c @@ -23,7 +23,7 @@ static int ksym_cmp(const void *p1, const void *p2) return ((struct ksym *)p1)->addr - ((struct ksym *)p2)->addr; } -int load_kallsyms(void) +int load_kallsyms_refresh(void) { FILE *f; char func[256], buf[256]; @@ -31,12 +31,7 @@ int load_kallsyms(void) void *addr; int i = 0; - /* - * This is called/used from multiplace places, - * load symbols just once. - */ - if (sym_cnt) - return 0; + sym_cnt = 0; f = fopen("/proc/kallsyms", "r"); if (!f) @@ -57,6 +52,17 @@ int load_kallsyms(void) return 0; } +int load_kallsyms(void) +{ + /* + * This is called/used from multiplace places, + * load symbols just once. + */ + if (sym_cnt) + return 0; + return load_kallsyms_refresh(); +} + struct ksym *ksym_search(long key) { int start = 0, end = sym_cnt; diff --git a/tools/testing/selftests/bpf/trace_helpers.h b/tools/testing/selftests/bpf/trace_helpers.h index 238a9c98cde2..53efde0e2998 100644 --- a/tools/testing/selftests/bpf/trace_helpers.h +++ b/tools/testing/selftests/bpf/trace_helpers.h @@ -10,6 +10,8 @@ struct ksym { }; int load_kallsyms(void); +int load_kallsyms_refresh(void); + struct ksym *ksym_search(long key); long ksym_get_addr(const char *name); |