This moves some functions and structs around to make the following patch easier to read. Signed-off-by: Jing Liu --- kernel/trace/bpf_trace.c | 304 +++++++++++++++++++-------------------- 1 file changed, 152 insertions(+), 152 deletions(-) diff --git a/kernel/trace/bpf_trace.c b/kernel/trace/bpf_trace.c index fe28d86f7c35..1fd07c10378f 100644 --- a/kernel/trace/bpf_trace.c +++ b/kernel/trace/bpf_trace.c @@ -2291,67 +2291,6 @@ struct bpf_kprobe_multi_run_ctx { unsigned long entry_ip; }; -struct user_syms { - const char **syms; - char *buf; -}; - -#ifndef CONFIG_HAVE_FTRACE_REGS_HAVING_PT_REGS -static DEFINE_PER_CPU(struct pt_regs, bpf_kprobe_multi_pt_regs); -#define bpf_kprobe_multi_pt_regs_ptr() this_cpu_ptr(&bpf_kprobe_multi_pt_regs) -#else -#define bpf_kprobe_multi_pt_regs_ptr() (NULL) -#endif - -static unsigned long ftrace_get_entry_ip(unsigned long fentry_ip) -{ - unsigned long ip = ftrace_get_symaddr(fentry_ip); - - return ip ? : fentry_ip; -} - -static int copy_user_syms(struct user_syms *us, unsigned long __user *usyms, u32 cnt) -{ - unsigned long __user usymbol; - const char **syms = NULL; - char *buf = NULL, *p; - int err = -ENOMEM; - unsigned int i; - - syms = kvmalloc_array(cnt, sizeof(*syms), GFP_KERNEL); - if (!syms) - goto error; - - buf = kvmalloc_array(cnt, KSYM_NAME_LEN, GFP_KERNEL); - if (!buf) - goto error; - - for (p = buf, i = 0; i < cnt; i++) { - if (__get_user(usymbol, usyms + i)) { - err = -EFAULT; - goto error; - } - err = strncpy_from_user(p, (const char __user *) usymbol, KSYM_NAME_LEN); - if (err == KSYM_NAME_LEN) - err = -E2BIG; - if (err < 0) - goto error; - syms[i] = p; - p += err + 1; - } - - us->syms = syms; - us->buf = buf; - return 0; - -error: - if (err) { - kvfree(syms); - kvfree(buf); - } - return err; -} - static void kprobe_multi_put_modules(struct module **mods, u32 cnt) { u32 i; @@ -2360,12 +2299,6 @@ static void kprobe_multi_put_modules(struct module **mods, u32 cnt) module_put(mods[i]); } -static void free_user_syms(struct user_syms *us) -{ - kvfree(us->syms); - kvfree(us->buf); -} - static void bpf_kprobe_multi_link_release(struct bpf_link *link) { struct bpf_kprobe_multi_link *kmulti_link; @@ -2469,6 +2402,152 @@ static const struct bpf_link_ops bpf_kprobe_multi_link_lops = { #endif }; +static u64 bpf_kprobe_multi_entry_ip(struct bpf_run_ctx *ctx) +{ + struct bpf_kprobe_multi_run_ctx *run_ctx; + + run_ctx = container_of(current->bpf_ctx, struct bpf_kprobe_multi_run_ctx, + session_ctx.run_ctx); + return run_ctx->entry_ip; +} + +struct modules_array { + struct module **mods; + int mods_cnt; + int mods_cap; +}; + +static int add_module(struct modules_array *arr, struct module *mod) +{ + struct module **mods; + + if (arr->mods_cnt == arr->mods_cap) { + arr->mods_cap = max(16, arr->mods_cap * 3 / 2); + mods = krealloc_array(arr->mods, arr->mods_cap, sizeof(*mods), GFP_KERNEL); + if (!mods) + return -ENOMEM; + arr->mods = mods; + } + + arr->mods[arr->mods_cnt] = mod; + arr->mods_cnt++; + return 0; +} + +static bool has_module(struct modules_array *arr, struct module *mod) +{ + int i; + + for (i = arr->mods_cnt - 1; i >= 0; i--) { + if (arr->mods[i] == mod) + return true; + } + return false; +} + +static int get_modules_for_addrs(struct module ***mods, unsigned long *addrs, u32 addrs_cnt) +{ + struct modules_array arr = {}; + u32 i, err = 0; + + for (i = 0; i < addrs_cnt; i++) { + bool skip_add = false; + struct module *mod; + + scoped_guard(rcu) { + mod = __module_address(addrs[i]); + /* Either no module or it's already stored */ + if (!mod || has_module(&arr, mod)) { + skip_add = true; + break; /* scoped_guard */ + } + if (!try_module_get(mod)) + err = -EINVAL; + } + if (skip_add) + continue; + if (err) + break; + err = add_module(&arr, mod); + if (err) { + module_put(mod); + break; + } + } + + /* We return either err < 0 in case of error, ... */ + if (err) { + kprobe_multi_put_modules(arr.mods, arr.mods_cnt); + kfree(arr.mods); + return err; + } + + /* or number of modules found if everything is ok. */ + *mods = arr.mods; + return arr.mods_cnt; +} + +struct user_syms { + const char **syms; + char *buf; +}; + +#ifndef CONFIG_HAVE_FTRACE_REGS_HAVING_PT_REGS +static DEFINE_PER_CPU(struct pt_regs, bpf_kprobe_multi_pt_regs); +#define bpf_kprobe_multi_pt_regs_ptr() this_cpu_ptr(&bpf_kprobe_multi_pt_regs) +#else +#define bpf_kprobe_multi_pt_regs_ptr() (NULL) +#endif + +static unsigned long ftrace_get_entry_ip(unsigned long fentry_ip) +{ + unsigned long ip = ftrace_get_symaddr(fentry_ip); + + return ip ? : fentry_ip; +} + +static int copy_user_syms(struct user_syms *us, unsigned long __user *usyms, u32 cnt) +{ + unsigned long __user usymbol; + const char **syms = NULL; + char *buf = NULL, *p; + int err = -ENOMEM; + unsigned int i; + + syms = kvmalloc_array(cnt, sizeof(*syms), GFP_KERNEL); + if (!syms) + goto error; + + buf = kvmalloc_array(cnt, KSYM_NAME_LEN, GFP_KERNEL); + if (!buf) + goto error; + + for (p = buf, i = 0; i < cnt; i++) { + if (__get_user(usymbol, usyms + i)) { + err = -EFAULT; + goto error; + } + err = strncpy_from_user(p, (const char __user *) usymbol, KSYM_NAME_LEN); + if (err == KSYM_NAME_LEN) + err = -E2BIG; + if (err < 0) + goto error; + syms[i] = p; + p += err + 1; + } + + us->syms = syms; + us->buf = buf; + return 0; + +error: + if (err) { + kvfree(syms); + kvfree(buf); + } + return err; +} + static void bpf_kprobe_multi_cookie_swap(void *a, void *b, int size, const void *priv) { const struct bpf_kprobe_multi_link *link = priv; @@ -2520,15 +2599,6 @@ static u64 bpf_kprobe_multi_cookie(struct bpf_run_ctx *ctx) return *cookie; } -static u64 bpf_kprobe_multi_entry_ip(struct bpf_run_ctx *ctx) -{ - struct bpf_kprobe_multi_run_ctx *run_ctx; - - run_ctx = container_of(current->bpf_ctx, struct bpf_kprobe_multi_run_ctx, - session_ctx.run_ctx); - return run_ctx->entry_ip; -} - static __always_inline int kprobe_multi_link_prog_run(struct bpf_kprobe_multi_link *link, unsigned long entry_ip, struct ftrace_regs *fregs, @@ -2597,6 +2667,12 @@ kprobe_multi_link_exit_handler(struct fprobe *fp, unsigned long fentry_ip, fregs, true, data); } +static void free_user_syms(struct user_syms *us) +{ + kvfree(us->syms); + kvfree(us->buf); +} + static int symbols_cmp_r(const void *a, const void *b, const void *priv) { const char **str_a = (const char **) a; @@ -2627,82 +2703,6 @@ static void symbols_swap_r(void *a, void *b, int size, const void *priv) } } -struct modules_array { - struct module **mods; - int mods_cnt; - int mods_cap; -}; - -static int add_module(struct modules_array *arr, struct module *mod) -{ - struct module **mods; - - if (arr->mods_cnt == arr->mods_cap) { - arr->mods_cap = max(16, arr->mods_cap * 3 / 2); - mods = krealloc_array(arr->mods, arr->mods_cap, sizeof(*mods), GFP_KERNEL); - if (!mods) - return -ENOMEM; - arr->mods = mods; - } - - arr->mods[arr->mods_cnt] = mod; - arr->mods_cnt++; - return 0; -} - -static bool has_module(struct modules_array *arr, struct module *mod) -{ - int i; - - for (i = arr->mods_cnt - 1; i >= 0; i--) { - if (arr->mods[i] == mod) - return true; - } - return false; -} - -static int get_modules_for_addrs(struct module ***mods, unsigned long *addrs, u32 addrs_cnt) -{ - struct modules_array arr = {}; - u32 i, err = 0; - - for (i = 0; i < addrs_cnt; i++) { - bool skip_add = false; - struct module *mod; - - scoped_guard(rcu) { - mod = __module_address(addrs[i]); - /* Either no module or it's already stored */ - if (!mod || has_module(&arr, mod)) { - skip_add = true; - break; /* scoped_guard */ - } - if (!try_module_get(mod)) - err = -EINVAL; - } - if (skip_add) - continue; - if (err) - break; - err = add_module(&arr, mod); - if (err) { - module_put(mod); - break; - } - } - - /* We return either err < 0 in case of error, ... */ - if (err) { - kprobe_multi_put_modules(arr.mods, arr.mods_cnt); - kfree(arr.mods); - return err; - } - - /* or number of modules found if everything is ok. */ - *mods = arr.mods; - return arr.mods_cnt; -} - static int addrs_check_error_injection_list(unsigned long *addrs, u32 cnt) { u32 i; -- 2.25.1 When fprobe is not available, provide a fallback implementation of kprobe_multi using the traditional kretprobe API. Uses kretprobe's entry_handler and handler callbacks to simulate fprobe's entry/exit functionality. Signed-off-by: Jing Liu --- kernel/trace/bpf_trace.c | 307 +++++++++++++++++++++++++++++++++++++-- 1 file changed, 295 insertions(+), 12 deletions(-) diff --git a/kernel/trace/bpf_trace.c b/kernel/trace/bpf_trace.c index 1fd07c10378f..426a1c627508 100644 --- a/kernel/trace/bpf_trace.c +++ b/kernel/trace/bpf_trace.c @@ -2274,12 +2274,44 @@ struct bpf_session_run_ctx { void *data; }; -#ifdef CONFIG_FPROBE +#if defined(CONFIG_FPROBE) || defined(CONFIG_KRETPROBES) +#ifndef CONFIG_FPROBE +struct bpf_kprobe { + struct bpf_kprobe_multi_link *link; + u64 cookie; + struct kretprobe rp; +}; + +static void bpf_kprobe_unregister(struct bpf_kprobe *kps, u32 cnt) +{ + for (int i = 0; i < cnt; i++) + unregister_kretprobe(&kps[i].rp); +} + +static int bpf_kprobe_register(struct bpf_kprobe *kps, u32 cnt) +{ + int ret = 0, i; + + for (i = 0; i < cnt; i++) { + ret = register_kretprobe(&kps[i].rp); + if (ret < 0) { + bpf_kprobe_unregister(kps, i); + break; + } + } + return ret; +} +#endif + struct bpf_kprobe_multi_link { struct bpf_link link; +#ifdef CONFIG_FPROBE struct fprobe fp; unsigned long *addrs; u64 *cookies; +#else + struct bpf_kprobe *kprobes; +#endif u32 cnt; u32 mods_cnt; struct module **mods; @@ -2287,7 +2319,11 @@ struct bpf_kprobe_multi_link { struct bpf_kprobe_multi_run_ctx { struct bpf_session_run_ctx session_ctx; +#ifdef CONFIG_FPROBE struct bpf_kprobe_multi_link *link; +#else + struct bpf_kprobe *kprobe; +#endif unsigned long entry_ip; }; @@ -2304,7 +2340,11 @@ static void bpf_kprobe_multi_link_release(struct bpf_link *link) struct bpf_kprobe_multi_link *kmulti_link; kmulti_link = container_of(link, struct bpf_kprobe_multi_link, link); +#ifdef CONFIG_FPROBE unregister_fprobe(&kmulti_link->fp); +#else + bpf_kprobe_unregister(kmulti_link->kprobes, kmulti_link->cnt); +#endif kprobe_multi_put_modules(kmulti_link->mods, kmulti_link->mods_cnt); } @@ -2313,8 +2353,12 @@ static void bpf_kprobe_multi_link_dealloc(struct bpf_link *link) struct bpf_kprobe_multi_link *kmulti_link; kmulti_link = container_of(link, struct bpf_kprobe_multi_link, link); +#ifdef CONFIG_FPROBE kvfree(kmulti_link->addrs); kvfree(kmulti_link->cookies); +#else + kvfree(kmulti_link->kprobes); +#endif kfree(kmulti_link->mods); kfree(kmulti_link); } @@ -2326,6 +2370,7 @@ static int bpf_kprobe_multi_link_fill_link_info(const struct bpf_link *link, u64 __user *uaddrs = u64_to_user_ptr(info->kprobe_multi.addrs); struct bpf_kprobe_multi_link *kmulti_link; u32 ucount = info->kprobe_multi.count; + bool kallsyms_show = kallsyms_show_value(current_cred()); int err = 0, i; if (!uaddrs ^ !ucount) @@ -2336,7 +2381,12 @@ static int bpf_kprobe_multi_link_fill_link_info(const struct bpf_link *link, kmulti_link = container_of(link, struct bpf_kprobe_multi_link, link); info->kprobe_multi.count = kmulti_link->cnt; info->kprobe_multi.flags = kmulti_link->link.flags; +#ifdef CONFIG_FPROBE info->kprobe_multi.missed = kmulti_link->fp.nmissed; +#else + for (i = 0; i < kmulti_link->cnt; i++) + info->kprobe_multi.missed += kmulti_link->kprobes[i].rp.nmissed; +#endif if (!uaddrs) return 0; @@ -2345,6 +2395,7 @@ static int bpf_kprobe_multi_link_fill_link_info(const struct bpf_link *link, else ucount = kmulti_link->cnt; +#ifdef CONFIG_FPROBE if (ucookies) { if (kmulti_link->cookies) { if (copy_to_user(ucookies, kmulti_link->cookies, ucount * sizeof(u64))) @@ -2357,7 +2408,7 @@ static int bpf_kprobe_multi_link_fill_link_info(const struct bpf_link *link, } } - if (kallsyms_show_value(current_cred())) { + if (kallsyms_show) { if (copy_to_user(uaddrs, kmulti_link->addrs, ucount * sizeof(u64))) return -EFAULT; } else { @@ -2366,6 +2417,16 @@ static int bpf_kprobe_multi_link_fill_link_info(const struct bpf_link *link, return -EFAULT; } } +#else + for (i = 0; i < ucount; i++) { + if (ucookies && put_user(kmulti_link->kprobes[i].cookie, ucookies + i)) + return -EFAULT; + + if (put_user(kallsyms_show ? (uintptr_t)kmulti_link->kprobes[i].rp.kp.addr : 0, + uaddrs + i)) + return -EFAULT; + } +#endif return err; } @@ -2374,21 +2435,32 @@ static void bpf_kprobe_multi_show_fdinfo(const struct bpf_link *link, struct seq_file *seq) { struct bpf_kprobe_multi_link *kmulti_link; + unsigned long kprobe_multi_missed = 0; kmulti_link = container_of(link, struct bpf_kprobe_multi_link, link); +#ifdef CONFIG_FPROBE + kprobe_multi_missed = kmulti_link->fp.nmissed; +#else + for (int i = 0; i < kmulti_link->cnt; i++) + kprobe_multi_missed += kmulti_link->kprobes[i].rp.nmissed; +#endif seq_printf(seq, "kprobe_cnt:\t%u\n" "missed:\t%lu\n", kmulti_link->cnt, - kmulti_link->fp.nmissed); + kprobe_multi_missed); seq_printf(seq, "%s\t %s\n", "cookie", "func"); for (int i = 0; i < kmulti_link->cnt; i++) { - seq_printf(seq, - "%llu\t %pS\n", - kmulti_link->cookies[i], - (void *)kmulti_link->addrs[i]); +#ifdef CONFIG_FPROBE + u64 cookie = kmulti_link->cookies[i]; + void *addr = (void *)kmulti_link->addrs[i]; +#else + u64 cookie = kmulti_link->kprobes[i].cookie; + void *addr = (void *)kmulti_link->kprobes[i].rp.kp.addr; +#endif + seq_printf(seq, "%llu\t %pS\n", cookie, addr); } } #endif @@ -2445,17 +2517,22 @@ static bool has_module(struct modules_array *arr, struct module *mod) return false; } -static int get_modules_for_addrs(struct module ***mods, unsigned long *addrs, u32 addrs_cnt) +static int get_modules_for_addrs(struct bpf_kprobe_multi_link *link) { struct modules_array arr = {}; u32 i, err = 0; - for (i = 0; i < addrs_cnt; i++) { + for (i = 0; i < link->cnt; i++) { bool skip_add = false; struct module *mod; +#ifdef CONFIG_FPROBE + unsigned long addr = link->addrs[i]; +#else + unsigned long addr = (unsigned long)link->kprobes[i].rp.kp.addr; +#endif scoped_guard(rcu) { - mod = __module_address(addrs[i]); + mod = __module_address(addr); /* Either no module or it's already stored */ if (!mod || has_module(&arr, mod)) { skip_add = true; @@ -2483,10 +2560,11 @@ static int get_modules_for_addrs(struct module ***mods, unsigned long *addrs, u3 } /* or number of modules found if everything is ok. */ - *mods = arr.mods; + link->mods = arr.mods; return arr.mods_cnt; } +#ifdef CONFIG_FPROBE struct user_syms { const char **syms; char *buf; @@ -2843,7 +2921,7 @@ int bpf_kprobe_multi_link_attach(const union bpf_attr *attr, struct bpf_prog *pr link); } - err = get_modules_for_addrs(&link->mods, addrs, cnt); + err = get_modules_for_addrs(link); if (err < 0) { bpf_link_cleanup(&link_primer); return err; @@ -2866,6 +2944,211 @@ int bpf_kprobe_multi_link_attach(const union bpf_attr *attr, struct bpf_prog *pr return err; } #else /* !CONFIG_FPROBE */ +static u64 bpf_kprobe_multi_cookie(struct bpf_run_ctx *ctx) +{ + struct bpf_kprobe_multi_run_ctx *run_ctx; + + run_ctx = container_of(current->bpf_ctx, struct bpf_kprobe_multi_run_ctx, + session_ctx.run_ctx); + return run_ctx->kprobe->cookie; +} + +static __always_inline int +kprobe_multi_link_prog_run(struct bpf_kprobe *kprobe, unsigned long entry_ip, + struct pt_regs *regs, bool is_return, void *data) +{ + struct bpf_kprobe_multi_link *link = kprobe->link; + struct bpf_kprobe_multi_run_ctx run_ctx = { + .session_ctx = { + .is_return = is_return, + .data = data, + }, + .kprobe = kprobe, + .entry_ip = entry_ip, + }; + struct bpf_run_ctx *old_run_ctx; + int err; + + cant_sleep(); + + if (unlikely(__this_cpu_inc_return(bpf_prog_active) != 1)) { + bpf_prog_inc_misses_counter(link->link.prog); + err = 1; + goto out; + } + + rcu_read_lock(); + migrate_disable(); + old_run_ctx = bpf_set_run_ctx(&run_ctx.session_ctx.run_ctx); + err = bpf_prog_run(link->link.prog, regs); + bpf_reset_run_ctx(old_run_ctx); + migrate_enable(); + rcu_read_unlock(); + + out: + __this_cpu_dec(bpf_prog_active); + return err; +} + +static int +kprobe_multi_link_handler(struct kretprobe_instance *ri, struct pt_regs *regs) +{ + struct kretprobe *rp = get_kretprobe(ri); + struct bpf_kprobe *kprobe; + int err; + + if (unlikely(!rp)) + return 1; + + kprobe = container_of(rp, struct bpf_kprobe, rp); + err = kprobe_multi_link_prog_run(kprobe, get_entry_ip((uintptr_t)rp->kp.addr), + regs, false, ri->data); + return is_kprobe_session(kprobe->link->link.prog) ? err : 0; +} + +static int +kprobe_multi_link_exit_handler(struct kretprobe_instance *ri, struct pt_regs *regs) +{ + struct kretprobe *rp = get_kretprobe(ri); + struct bpf_kprobe *kprobe; + + if (unlikely(!rp)) + return 0; + + kprobe = container_of(rp, struct bpf_kprobe, rp); + kprobe_multi_link_prog_run(kprobe, get_entry_ip((uintptr_t)rp->kp.addr), + regs, true, ri->data); + return 0; +} + +int bpf_kprobe_multi_link_attach(const union bpf_attr *attr, struct bpf_prog *prog) +{ + struct bpf_kprobe_multi_link *link = NULL; + struct bpf_link_primer link_primer; + struct bpf_kprobe *kprobes = NULL; + u32 flags, cnt; + u64 __user *ucookies; + unsigned long __user *uaddrs; + unsigned long __user *usyms; + int err, i; + + /* no support for 32bit archs yet */ + if (sizeof(u64) != sizeof(void *)) + return -EOPNOTSUPP; + + if (attr->link_create.flags) + return -EINVAL; + + if (!is_kprobe_multi(prog)) + return -EINVAL; + + /* Writing to context is not allowed for kprobes. */ + if (prog->aux->kprobe_write_ctx) + return -EINVAL; + + flags = attr->link_create.kprobe_multi.flags; + if (flags & ~BPF_F_KPROBE_MULTI_RETURN) + return -EINVAL; + + uaddrs = u64_to_user_ptr(attr->link_create.kprobe_multi.addrs); + usyms = u64_to_user_ptr(attr->link_create.kprobe_multi.syms); + if (!!uaddrs == !!usyms) + return -EINVAL; + + cnt = attr->link_create.kprobe_multi.cnt; + if (!cnt) + return -EINVAL; + if (cnt > MAX_KPROBE_MULTI_CNT) + return -E2BIG; + + ucookies = u64_to_user_ptr(attr->link_create.kprobe_multi.cookies); + kprobes = kvcalloc(cnt, sizeof(*kprobes), GFP_KERNEL); + link = kzalloc(sizeof(*link), GFP_KERNEL); + if (!link || !kprobes) { + err = -ENOMEM; + goto error; + } + + for (i = 0; i < cnt; i++) { + unsigned long addr; + + if (uaddrs) { + if (__get_user(addr, uaddrs + i)) { + err = -EFAULT; + goto error; + } + } else { + unsigned long __user usymbol; + char buf[KSYM_NAME_LEN]; + + if (__get_user(usymbol, usyms + i)) { + err = -EFAULT; + goto error; + } + err = strncpy_from_user(buf, (const char __user *) usymbol, KSYM_NAME_LEN); + if (err == KSYM_NAME_LEN) + err = -E2BIG; + if (err < 0) + goto error; + + addr = kallsyms_lookup_name(buf); + if (!addr) + goto error; + } + if (prog->kprobe_override && !within_error_injection_list(addr)) { + err = -EINVAL; + goto error; + } + if (ucookies && __get_user(kprobes[i].cookie, ucookies + i)) { + err = -EFAULT; + goto error; + } + + kprobes[i].link = link; + kprobes[i].rp.kp.addr = (kprobe_opcode_t *)addr; + + if (!(flags & BPF_F_KPROBE_MULTI_RETURN)) + kprobes[i].rp.entry_handler = kprobe_multi_link_handler; + if ((flags & BPF_F_KPROBE_MULTI_RETURN) || is_kprobe_session(prog)) + kprobes[i].rp.handler = kprobe_multi_link_exit_handler; + if (is_kprobe_session(prog)) + kprobes[i].rp.data_size = sizeof(u64); + } + + bpf_link_init(&link->link, BPF_LINK_TYPE_KPROBE_MULTI, + &bpf_kprobe_multi_link_lops, prog, attr->link_create.attach_type); + + err = bpf_link_prime(&link->link, &link_primer); + if (err) + goto error; + + link->kprobes = kprobes; + link->cnt = cnt; + link->link.flags = flags; + + err = get_modules_for_addrs(link); + if (err < 0) { + bpf_link_cleanup(&link_primer); + return err; + } + link->mods_cnt = err; + + err = bpf_kprobe_register(kprobes, cnt); + if (err) { + kprobe_multi_put_modules(link->mods, link->mods_cnt); + bpf_link_cleanup(&link_primer); + return err; + } + + return bpf_link_settle(&link_primer); + +error: + kvfree(kprobes); + kfree(link); + return err; +} +#endif +#else /* !CONFIG_FPROBE && !CONFIG_KRETPROBES*/ int bpf_kprobe_multi_link_attach(const union bpf_attr *attr, struct bpf_prog *prog) { return -EOPNOTSUPP; -- 2.25.1