diff options
Diffstat (limited to 'kernel/trace/bpf_trace.c')
| -rw-r--r-- | kernel/trace/bpf_trace.c | 190 |
1 files changed, 146 insertions, 44 deletions
diff --git a/kernel/trace/bpf_trace.c b/kernel/trace/bpf_trace.c index 1ed08967fb97..e8da032bb6fc 100644 --- a/kernel/trace/bpf_trace.c +++ b/kernel/trace/bpf_trace.c @@ -6,6 +6,7 @@ #include <linux/types.h> #include <linux/slab.h> #include <linux/bpf.h> +#include <linux/bpf_verifier.h> #include <linux/bpf_perf_event.h> #include <linux/btf.h> #include <linux/filter.h> @@ -368,8 +369,6 @@ static const struct bpf_func_proto *bpf_get_probe_write_proto(void) return &bpf_probe_write_user_proto; } -static DEFINE_RAW_SPINLOCK(trace_printk_lock); - #define MAX_TRACE_PRINTK_VARARGS 3 #define BPF_TRACE_PRINTK_SIZE 1024 @@ -377,23 +376,22 @@ BPF_CALL_5(bpf_trace_printk, char *, fmt, u32, fmt_size, u64, arg1, u64, arg2, u64, arg3) { u64 args[MAX_TRACE_PRINTK_VARARGS] = { arg1, arg2, arg3 }; - u32 *bin_args; - static char buf[BPF_TRACE_PRINTK_SIZE]; - unsigned long flags; + struct bpf_bprintf_data data = { + .get_bin_args = true, + .get_buf = true, + }; int ret; - ret = bpf_bprintf_prepare(fmt, fmt_size, args, &bin_args, - MAX_TRACE_PRINTK_VARARGS); + ret = bpf_bprintf_prepare(fmt, fmt_size, args, + MAX_TRACE_PRINTK_VARARGS, &data); if (ret < 0) return ret; - raw_spin_lock_irqsave(&trace_printk_lock, flags); - ret = bstr_printf(buf, sizeof(buf), fmt, bin_args); + ret = bstr_printf(data.buf, MAX_BPRINTF_BUF, fmt, data.bin_args); - trace_bpf_trace_printk(buf); - raw_spin_unlock_irqrestore(&trace_printk_lock, flags); + trace_bpf_trace_printk(data.buf); - bpf_bprintf_cleanup(); + bpf_bprintf_cleanup(&data); return ret; } @@ -426,30 +424,29 @@ const struct bpf_func_proto *bpf_get_trace_printk_proto(void) return &bpf_trace_printk_proto; } -BPF_CALL_4(bpf_trace_vprintk, char *, fmt, u32, fmt_size, const void *, data, +BPF_CALL_4(bpf_trace_vprintk, char *, fmt, u32, fmt_size, const void *, args, u32, data_len) { - static char buf[BPF_TRACE_PRINTK_SIZE]; - unsigned long flags; + struct bpf_bprintf_data data = { + .get_bin_args = true, + .get_buf = true, + }; int ret, num_args; - u32 *bin_args; if (data_len & 7 || data_len > MAX_BPRINTF_VARARGS * 8 || - (data_len && !data)) + (data_len && !args)) return -EINVAL; num_args = data_len / 8; - ret = bpf_bprintf_prepare(fmt, fmt_size, data, &bin_args, num_args); + ret = bpf_bprintf_prepare(fmt, fmt_size, args, num_args, &data); if (ret < 0) return ret; - raw_spin_lock_irqsave(&trace_printk_lock, flags); - ret = bstr_printf(buf, sizeof(buf), fmt, bin_args); + ret = bstr_printf(data.buf, MAX_BPRINTF_BUF, fmt, data.bin_args); - trace_bpf_trace_printk(buf); - raw_spin_unlock_irqrestore(&trace_printk_lock, flags); + trace_bpf_trace_printk(data.buf); - bpf_bprintf_cleanup(); + bpf_bprintf_cleanup(&data); return ret; } @@ -471,23 +468,25 @@ const struct bpf_func_proto *bpf_get_trace_vprintk_proto(void) } BPF_CALL_5(bpf_seq_printf, struct seq_file *, m, char *, fmt, u32, fmt_size, - const void *, data, u32, data_len) + const void *, args, u32, data_len) { + struct bpf_bprintf_data data = { + .get_bin_args = true, + }; int err, num_args; - u32 *bin_args; if (data_len & 7 || data_len > MAX_BPRINTF_VARARGS * 8 || - (data_len && !data)) + (data_len && !args)) return -EINVAL; num_args = data_len / 8; - err = bpf_bprintf_prepare(fmt, fmt_size, data, &bin_args, num_args); + err = bpf_bprintf_prepare(fmt, fmt_size, args, num_args, &data); if (err < 0) return err; - seq_bprintf(m, fmt, bin_args); + seq_bprintf(m, fmt, data.bin_args); - bpf_bprintf_cleanup(); + bpf_bprintf_cleanup(&data); return seq_has_overflowed(m) ? -EOVERFLOW : 0; } @@ -686,8 +685,7 @@ BPF_CALL_5(bpf_perf_event_output, struct pt_regs *, regs, struct bpf_map *, map, } perf_sample_data_init(sd, 0, 0); - sd->raw = &raw; - sd->sample_flags |= PERF_SAMPLE_RAW; + perf_sample_save_raw_data(sd, &raw); err = __bpf_perf_event_output(regs, map, flags, sd); @@ -745,8 +743,7 @@ u64 bpf_event_output(struct bpf_map *map, u64 flags, void *meta, u64 meta_size, perf_fetch_caller_regs(regs); perf_sample_data_init(sd, 0, 0); - sd->raw = &raw; - sd->sample_flags |= PERF_SAMPLE_RAW; + perf_sample_save_raw_data(sd, &raw); ret = __bpf_perf_event_output(regs, map, flags, sd); out: @@ -773,7 +770,7 @@ BPF_CALL_0(bpf_get_current_task_btf) const struct bpf_func_proto bpf_get_current_task_btf_proto = { .func = bpf_get_current_task_btf, .gpl_only = true, - .ret_type = RET_PTR_TO_BTF_ID, + .ret_type = RET_PTR_TO_BTF_ID_TRUSTED, .ret_btf_id = &btf_tracing_ids[BTF_TRACING_TYPE_TASK], }; @@ -832,6 +829,7 @@ static void do_bpf_send_signal(struct irq_work *entry) work = container_of(entry, struct send_signal_irq_work, irq_work); group_send_sig_info(work->sig, SEND_SIG_PRIV, work->task, work->type); + put_task_struct(work->task); } static int bpf_send_signal_common(u32 sig, enum pid_type type) @@ -847,6 +845,9 @@ static int bpf_send_signal_common(u32 sig, enum pid_type type) return -EPERM; if (unlikely(!nmi_uaccess_okay())) return -EPERM; + /* Task should not be pid=1 to avoid kernel panic. */ + if (unlikely(is_global_init(current))) + return -EPERM; if (irqs_disabled()) { /* Do an early check on signal validity. Otherwise, @@ -863,7 +864,7 @@ static int bpf_send_signal_common(u32 sig, enum pid_type type) * to the irq_work. The current task may change when queued * irq works get executed. */ - work->task = current; + work->task = get_task_struct(current); work->sig = sig; work->type = type; irq_work_queue(&work->irq_work); @@ -1234,7 +1235,7 @@ __diag_ignore_all("-Wmissing-prototypes", * Return: a bpf_key pointer with a valid key pointer if the key is found, a * NULL pointer otherwise. */ -struct bpf_key *bpf_lookup_user_key(u32 serial, u64 flags) +__bpf_kfunc struct bpf_key *bpf_lookup_user_key(u32 serial, u64 flags) { key_ref_t key_ref; struct bpf_key *bkey; @@ -1283,7 +1284,7 @@ struct bpf_key *bpf_lookup_user_key(u32 serial, u64 flags) * Return: a bpf_key pointer with an invalid key pointer set from the * pre-determined ID on success, a NULL pointer otherwise */ -struct bpf_key *bpf_lookup_system_key(u64 id) +__bpf_kfunc struct bpf_key *bpf_lookup_system_key(u64 id) { struct bpf_key *bkey; @@ -1307,7 +1308,7 @@ struct bpf_key *bpf_lookup_system_key(u64 id) * Decrement the reference count of the key inside *bkey*, if the pointer * is valid, and free *bkey*. */ -void bpf_key_put(struct bpf_key *bkey) +__bpf_kfunc void bpf_key_put(struct bpf_key *bkey) { if (bkey->has_ref) key_put(bkey->key); @@ -1327,7 +1328,7 @@ void bpf_key_put(struct bpf_key *bkey) * * Return: 0 on success, a negative value on error. */ -int bpf_verify_pkcs7_signature(struct bpf_dynptr_kern *data_ptr, +__bpf_kfunc int bpf_verify_pkcs7_signature(struct bpf_dynptr_kern *data_ptr, struct bpf_dynptr_kern *sig_ptr, struct bpf_key *trusted_keyring) { @@ -1456,6 +1457,10 @@ bpf_tracing_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog) return &bpf_get_current_cgroup_id_proto; case BPF_FUNC_get_current_ancestor_cgroup_id: return &bpf_get_current_ancestor_cgroup_id_proto; + case BPF_FUNC_cgrp_storage_get: + return &bpf_cgrp_storage_get_proto; + case BPF_FUNC_cgrp_storage_delete: + return &bpf_cgrp_storage_delete_proto; #endif case BPF_FUNC_send_signal: return &bpf_send_signal_proto; @@ -1480,9 +1485,9 @@ bpf_tracing_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog) case BPF_FUNC_get_task_stack: return &bpf_get_task_stack_proto; case BPF_FUNC_copy_from_user: - return prog->aux->sleepable ? &bpf_copy_from_user_proto : NULL; + return &bpf_copy_from_user_proto; case BPF_FUNC_copy_from_user_task: - return prog->aux->sleepable ? &bpf_copy_from_user_task_proto : NULL; + return &bpf_copy_from_user_task_proto; case BPF_FUNC_snprintf_btf: return &bpf_snprintf_btf_proto; case BPF_FUNC_per_cpu_ptr: @@ -1490,8 +1495,12 @@ bpf_tracing_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog) case BPF_FUNC_this_cpu_ptr: return &bpf_this_cpu_ptr_proto; case BPF_FUNC_task_storage_get: + if (bpf_prog_check_recur(prog)) + return &bpf_task_storage_get_recur_proto; return &bpf_task_storage_get_proto; case BPF_FUNC_task_storage_delete: + if (bpf_prog_check_recur(prog)) + return &bpf_task_storage_delete_recur_proto; return &bpf_task_storage_delete_proto; case BPF_FUNC_for_each_map_elem: return &bpf_for_each_map_elem_proto; @@ -2452,6 +2461,8 @@ struct bpf_kprobe_multi_link { unsigned long *addrs; u64 *cookies; u32 cnt; + u32 mods_cnt; + struct module **mods; }; struct bpf_kprobe_multi_run_ctx { @@ -2507,6 +2518,14 @@ 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); @@ -2519,6 +2538,7 @@ 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) @@ -2528,6 +2548,7 @@ 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); } @@ -2550,7 +2571,7 @@ 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; @@ -2561,7 +2582,7 @@ 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) @@ -2579,7 +2600,7 @@ 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); @@ -2663,6 +2684,79 @@ 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++) { + struct module *mod; + + preempt_disable(); + mod = __module_address(addrs[i]); + /* Either no module or we it's already stored */ + if (!mod || has_module(&arr, mod)) { + preempt_enable(); + continue; + } + if (!try_module_get(mod)) + err = -EINVAL; + preempt_enable(); + 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; +} + int bpf_kprobe_multi_link_attach(const union bpf_attr *attr, struct bpf_prog *prog) { struct bpf_kprobe_multi_link *link = NULL; @@ -2775,8 +2869,16 @@ 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); + 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; } |