1 // SPDX-License-Identifier: GPL-2.0-only
2 /* Copyright (c) 2011-2014 PLUMgrid, http://plumgrid.com
6 #include <linux/bpf-cgroup.h>
7 #include <linux/cgroup.h>
8 #include <linux/rcupdate.h>
9 #include <linux/random.h>
10 #include <linux/smp.h>
11 #include <linux/topology.h>
12 #include <linux/ktime.h>
13 #include <linux/sched.h>
14 #include <linux/uidgid.h>
15 #include <linux/filter.h>
16 #include <linux/ctype.h>
17 #include <linux/jiffies.h>
18 #include <linux/pid_namespace.h>
19 #include <linux/poison.h>
20 #include <linux/proc_ns.h>
21 #include <linux/security.h>
22 #include <linux/btf_ids.h>
23 #include <linux/bpf_mem_alloc.h>
25 #include "../../lib/kstrtox.h"
27 /* If kernel subsystem is allowing eBPF programs to call this function,
28 * inside its own verifier_ops->get_func_proto() callback it should return
29 * bpf_map_lookup_elem_proto, so that verifier can properly check the arguments
31 * Different map implementations will rely on rcu in map methods
32 * lookup/update/delete, therefore eBPF programs must run under rcu lock
33 * if program is allowed to access maps, so check rcu_read_lock_held in
34 * all three functions.
36 BPF_CALL_2(bpf_map_lookup_elem, struct bpf_map *, map, void *, key)
38 WARN_ON_ONCE(!rcu_read_lock_held() && !rcu_read_lock_bh_held());
39 return (unsigned long) map->ops->map_lookup_elem(map, key);
42 const struct bpf_func_proto bpf_map_lookup_elem_proto = {
43 .func = bpf_map_lookup_elem,
46 .ret_type = RET_PTR_TO_MAP_VALUE_OR_NULL,
47 .arg1_type = ARG_CONST_MAP_PTR,
48 .arg2_type = ARG_PTR_TO_MAP_KEY,
51 BPF_CALL_4(bpf_map_update_elem, struct bpf_map *, map, void *, key,
52 void *, value, u64, flags)
54 WARN_ON_ONCE(!rcu_read_lock_held() && !rcu_read_lock_bh_held());
55 return map->ops->map_update_elem(map, key, value, flags);
58 const struct bpf_func_proto bpf_map_update_elem_proto = {
59 .func = bpf_map_update_elem,
62 .ret_type = RET_INTEGER,
63 .arg1_type = ARG_CONST_MAP_PTR,
64 .arg2_type = ARG_PTR_TO_MAP_KEY,
65 .arg3_type = ARG_PTR_TO_MAP_VALUE,
66 .arg4_type = ARG_ANYTHING,
69 BPF_CALL_2(bpf_map_delete_elem, struct bpf_map *, map, void *, key)
71 WARN_ON_ONCE(!rcu_read_lock_held() && !rcu_read_lock_bh_held());
72 return map->ops->map_delete_elem(map, key);
75 const struct bpf_func_proto bpf_map_delete_elem_proto = {
76 .func = bpf_map_delete_elem,
79 .ret_type = RET_INTEGER,
80 .arg1_type = ARG_CONST_MAP_PTR,
81 .arg2_type = ARG_PTR_TO_MAP_KEY,
84 BPF_CALL_3(bpf_map_push_elem, struct bpf_map *, map, void *, value, u64, flags)
86 return map->ops->map_push_elem(map, value, flags);
89 const struct bpf_func_proto bpf_map_push_elem_proto = {
90 .func = bpf_map_push_elem,
93 .ret_type = RET_INTEGER,
94 .arg1_type = ARG_CONST_MAP_PTR,
95 .arg2_type = ARG_PTR_TO_MAP_VALUE,
96 .arg3_type = ARG_ANYTHING,
99 BPF_CALL_2(bpf_map_pop_elem, struct bpf_map *, map, void *, value)
101 return map->ops->map_pop_elem(map, value);
104 const struct bpf_func_proto bpf_map_pop_elem_proto = {
105 .func = bpf_map_pop_elem,
107 .ret_type = RET_INTEGER,
108 .arg1_type = ARG_CONST_MAP_PTR,
109 .arg2_type = ARG_PTR_TO_MAP_VALUE | MEM_UNINIT,
112 BPF_CALL_2(bpf_map_peek_elem, struct bpf_map *, map, void *, value)
114 return map->ops->map_peek_elem(map, value);
117 const struct bpf_func_proto bpf_map_peek_elem_proto = {
118 .func = bpf_map_peek_elem,
120 .ret_type = RET_INTEGER,
121 .arg1_type = ARG_CONST_MAP_PTR,
122 .arg2_type = ARG_PTR_TO_MAP_VALUE | MEM_UNINIT,
125 BPF_CALL_3(bpf_map_lookup_percpu_elem, struct bpf_map *, map, void *, key, u32, cpu)
127 WARN_ON_ONCE(!rcu_read_lock_held() && !rcu_read_lock_bh_held());
128 return (unsigned long) map->ops->map_lookup_percpu_elem(map, key, cpu);
131 const struct bpf_func_proto bpf_map_lookup_percpu_elem_proto = {
132 .func = bpf_map_lookup_percpu_elem,
135 .ret_type = RET_PTR_TO_MAP_VALUE_OR_NULL,
136 .arg1_type = ARG_CONST_MAP_PTR,
137 .arg2_type = ARG_PTR_TO_MAP_KEY,
138 .arg3_type = ARG_ANYTHING,
141 const struct bpf_func_proto bpf_get_prandom_u32_proto = {
142 .func = bpf_user_rnd_u32,
144 .ret_type = RET_INTEGER,
147 BPF_CALL_0(bpf_get_smp_processor_id)
149 return smp_processor_id();
152 const struct bpf_func_proto bpf_get_smp_processor_id_proto = {
153 .func = bpf_get_smp_processor_id,
155 .ret_type = RET_INTEGER,
158 BPF_CALL_0(bpf_get_numa_node_id)
160 return numa_node_id();
163 const struct bpf_func_proto bpf_get_numa_node_id_proto = {
164 .func = bpf_get_numa_node_id,
166 .ret_type = RET_INTEGER,
169 BPF_CALL_0(bpf_ktime_get_ns)
171 /* NMI safe access to clock monotonic */
172 return ktime_get_mono_fast_ns();
175 const struct bpf_func_proto bpf_ktime_get_ns_proto = {
176 .func = bpf_ktime_get_ns,
178 .ret_type = RET_INTEGER,
181 BPF_CALL_0(bpf_ktime_get_boot_ns)
183 /* NMI safe access to clock boottime */
184 return ktime_get_boot_fast_ns();
187 const struct bpf_func_proto bpf_ktime_get_boot_ns_proto = {
188 .func = bpf_ktime_get_boot_ns,
190 .ret_type = RET_INTEGER,
193 BPF_CALL_0(bpf_ktime_get_coarse_ns)
195 return ktime_get_coarse_ns();
198 const struct bpf_func_proto bpf_ktime_get_coarse_ns_proto = {
199 .func = bpf_ktime_get_coarse_ns,
201 .ret_type = RET_INTEGER,
204 BPF_CALL_0(bpf_ktime_get_tai_ns)
206 /* NMI safe access to clock tai */
207 return ktime_get_tai_fast_ns();
210 const struct bpf_func_proto bpf_ktime_get_tai_ns_proto = {
211 .func = bpf_ktime_get_tai_ns,
213 .ret_type = RET_INTEGER,
216 BPF_CALL_0(bpf_get_current_pid_tgid)
218 struct task_struct *task = current;
223 return (u64) task->tgid << 32 | task->pid;
226 const struct bpf_func_proto bpf_get_current_pid_tgid_proto = {
227 .func = bpf_get_current_pid_tgid,
229 .ret_type = RET_INTEGER,
232 BPF_CALL_0(bpf_get_current_uid_gid)
234 struct task_struct *task = current;
241 current_uid_gid(&uid, &gid);
242 return (u64) from_kgid(&init_user_ns, gid) << 32 |
243 from_kuid(&init_user_ns, uid);
246 const struct bpf_func_proto bpf_get_current_uid_gid_proto = {
247 .func = bpf_get_current_uid_gid,
249 .ret_type = RET_INTEGER,
252 BPF_CALL_2(bpf_get_current_comm, char *, buf, u32, size)
254 struct task_struct *task = current;
259 /* Verifier guarantees that size > 0 */
260 strscpy(buf, task->comm, size);
263 memset(buf, 0, size);
267 const struct bpf_func_proto bpf_get_current_comm_proto = {
268 .func = bpf_get_current_comm,
270 .ret_type = RET_INTEGER,
271 .arg1_type = ARG_PTR_TO_UNINIT_MEM,
272 .arg2_type = ARG_CONST_SIZE,
275 #if defined(CONFIG_QUEUED_SPINLOCKS) || defined(CONFIG_BPF_ARCH_SPINLOCK)
277 static inline void __bpf_spin_lock(struct bpf_spin_lock *lock)
279 arch_spinlock_t *l = (void *)lock;
282 arch_spinlock_t lock;
283 } u = { .lock = __ARCH_SPIN_LOCK_UNLOCKED };
285 compiletime_assert(u.val == 0, "__ARCH_SPIN_LOCK_UNLOCKED not 0");
286 BUILD_BUG_ON(sizeof(*l) != sizeof(__u32));
287 BUILD_BUG_ON(sizeof(*lock) != sizeof(__u32));
291 static inline void __bpf_spin_unlock(struct bpf_spin_lock *lock)
293 arch_spinlock_t *l = (void *)lock;
300 static inline void __bpf_spin_lock(struct bpf_spin_lock *lock)
302 atomic_t *l = (void *)lock;
304 BUILD_BUG_ON(sizeof(*l) != sizeof(*lock));
306 atomic_cond_read_relaxed(l, !VAL);
307 } while (atomic_xchg(l, 1));
310 static inline void __bpf_spin_unlock(struct bpf_spin_lock *lock)
312 atomic_t *l = (void *)lock;
314 atomic_set_release(l, 0);
319 static DEFINE_PER_CPU(unsigned long, irqsave_flags);
321 static inline void __bpf_spin_lock_irqsave(struct bpf_spin_lock *lock)
325 local_irq_save(flags);
326 __bpf_spin_lock(lock);
327 __this_cpu_write(irqsave_flags, flags);
330 notrace BPF_CALL_1(bpf_spin_lock, struct bpf_spin_lock *, lock)
332 __bpf_spin_lock_irqsave(lock);
336 const struct bpf_func_proto bpf_spin_lock_proto = {
337 .func = bpf_spin_lock,
339 .ret_type = RET_VOID,
340 .arg1_type = ARG_PTR_TO_SPIN_LOCK,
341 .arg1_btf_id = BPF_PTR_POISON,
344 static inline void __bpf_spin_unlock_irqrestore(struct bpf_spin_lock *lock)
348 flags = __this_cpu_read(irqsave_flags);
349 __bpf_spin_unlock(lock);
350 local_irq_restore(flags);
353 notrace BPF_CALL_1(bpf_spin_unlock, struct bpf_spin_lock *, lock)
355 __bpf_spin_unlock_irqrestore(lock);
359 const struct bpf_func_proto bpf_spin_unlock_proto = {
360 .func = bpf_spin_unlock,
362 .ret_type = RET_VOID,
363 .arg1_type = ARG_PTR_TO_SPIN_LOCK,
364 .arg1_btf_id = BPF_PTR_POISON,
367 void copy_map_value_locked(struct bpf_map *map, void *dst, void *src,
370 struct bpf_spin_lock *lock;
373 lock = src + map->record->spin_lock_off;
375 lock = dst + map->record->spin_lock_off;
377 __bpf_spin_lock_irqsave(lock);
378 copy_map_value(map, dst, src);
379 __bpf_spin_unlock_irqrestore(lock);
383 BPF_CALL_0(bpf_jiffies64)
385 return get_jiffies_64();
388 const struct bpf_func_proto bpf_jiffies64_proto = {
389 .func = bpf_jiffies64,
391 .ret_type = RET_INTEGER,
394 #ifdef CONFIG_CGROUPS
395 BPF_CALL_0(bpf_get_current_cgroup_id)
401 cgrp = task_dfl_cgroup(current);
402 cgrp_id = cgroup_id(cgrp);
408 const struct bpf_func_proto bpf_get_current_cgroup_id_proto = {
409 .func = bpf_get_current_cgroup_id,
411 .ret_type = RET_INTEGER,
414 BPF_CALL_1(bpf_get_current_ancestor_cgroup_id, int, ancestor_level)
417 struct cgroup *ancestor;
421 cgrp = task_dfl_cgroup(current);
422 ancestor = cgroup_ancestor(cgrp, ancestor_level);
423 cgrp_id = ancestor ? cgroup_id(ancestor) : 0;
429 const struct bpf_func_proto bpf_get_current_ancestor_cgroup_id_proto = {
430 .func = bpf_get_current_ancestor_cgroup_id,
432 .ret_type = RET_INTEGER,
433 .arg1_type = ARG_ANYTHING,
435 #endif /* CONFIG_CGROUPS */
437 #define BPF_STRTOX_BASE_MASK 0x1F
439 static int __bpf_strtoull(const char *buf, size_t buf_len, u64 flags,
440 unsigned long long *res, bool *is_negative)
442 unsigned int base = flags & BPF_STRTOX_BASE_MASK;
443 const char *cur_buf = buf;
444 size_t cur_len = buf_len;
445 unsigned int consumed;
449 if (!buf || !buf_len || !res || !is_negative)
452 if (base != 0 && base != 8 && base != 10 && base != 16)
455 if (flags & ~BPF_STRTOX_BASE_MASK)
458 while (cur_buf < buf + buf_len && isspace(*cur_buf))
461 *is_negative = (cur_buf < buf + buf_len && *cur_buf == '-');
465 consumed = cur_buf - buf;
470 cur_len = min(cur_len, sizeof(str) - 1);
471 memcpy(str, cur_buf, cur_len);
475 cur_buf = _parse_integer_fixup_radix(cur_buf, &base);
476 val_len = _parse_integer(cur_buf, base, res);
478 if (val_len & KSTRTOX_OVERFLOW)
485 consumed += cur_buf - str;
490 static int __bpf_strtoll(const char *buf, size_t buf_len, u64 flags,
493 unsigned long long _res;
497 err = __bpf_strtoull(buf, buf_len, flags, &_res, &is_negative);
501 if ((long long)-_res > 0)
505 if ((long long)_res < 0)
512 BPF_CALL_4(bpf_strtol, const char *, buf, size_t, buf_len, u64, flags,
518 err = __bpf_strtoll(buf, buf_len, flags, &_res);
521 if (_res != (long)_res)
527 const struct bpf_func_proto bpf_strtol_proto = {
530 .ret_type = RET_INTEGER,
531 .arg1_type = ARG_PTR_TO_MEM | MEM_RDONLY,
532 .arg2_type = ARG_CONST_SIZE,
533 .arg3_type = ARG_ANYTHING,
534 .arg4_type = ARG_PTR_TO_LONG,
537 BPF_CALL_4(bpf_strtoul, const char *, buf, size_t, buf_len, u64, flags,
538 unsigned long *, res)
540 unsigned long long _res;
544 err = __bpf_strtoull(buf, buf_len, flags, &_res, &is_negative);
549 if (_res != (unsigned long)_res)
555 const struct bpf_func_proto bpf_strtoul_proto = {
558 .ret_type = RET_INTEGER,
559 .arg1_type = ARG_PTR_TO_MEM | MEM_RDONLY,
560 .arg2_type = ARG_CONST_SIZE,
561 .arg3_type = ARG_ANYTHING,
562 .arg4_type = ARG_PTR_TO_LONG,
565 BPF_CALL_3(bpf_strncmp, const char *, s1, u32, s1_sz, const char *, s2)
567 return strncmp(s1, s2, s1_sz);
570 static const struct bpf_func_proto bpf_strncmp_proto = {
573 .ret_type = RET_INTEGER,
574 .arg1_type = ARG_PTR_TO_MEM,
575 .arg2_type = ARG_CONST_SIZE,
576 .arg3_type = ARG_PTR_TO_CONST_STR,
579 BPF_CALL_4(bpf_get_ns_current_pid_tgid, u64, dev, u64, ino,
580 struct bpf_pidns_info *, nsdata, u32, size)
582 struct task_struct *task = current;
583 struct pid_namespace *pidns;
586 if (unlikely(size != sizeof(struct bpf_pidns_info)))
589 if (unlikely((u64)(dev_t)dev != dev))
595 pidns = task_active_pid_ns(task);
596 if (unlikely(!pidns)) {
601 if (!ns_match(&pidns->ns, (dev_t)dev, ino))
604 nsdata->pid = task_pid_nr_ns(task, pidns);
605 nsdata->tgid = task_tgid_nr_ns(task, pidns);
608 memset((void *)nsdata, 0, (size_t) size);
612 const struct bpf_func_proto bpf_get_ns_current_pid_tgid_proto = {
613 .func = bpf_get_ns_current_pid_tgid,
615 .ret_type = RET_INTEGER,
616 .arg1_type = ARG_ANYTHING,
617 .arg2_type = ARG_ANYTHING,
618 .arg3_type = ARG_PTR_TO_UNINIT_MEM,
619 .arg4_type = ARG_CONST_SIZE,
622 static const struct bpf_func_proto bpf_get_raw_smp_processor_id_proto = {
623 .func = bpf_get_raw_cpu_id,
625 .ret_type = RET_INTEGER,
628 BPF_CALL_5(bpf_event_output_data, void *, ctx, struct bpf_map *, map,
629 u64, flags, void *, data, u64, size)
631 if (unlikely(flags & ~(BPF_F_INDEX_MASK)))
634 return bpf_event_output(map, flags, data, size, NULL, 0, NULL);
637 const struct bpf_func_proto bpf_event_output_data_proto = {
638 .func = bpf_event_output_data,
640 .ret_type = RET_INTEGER,
641 .arg1_type = ARG_PTR_TO_CTX,
642 .arg2_type = ARG_CONST_MAP_PTR,
643 .arg3_type = ARG_ANYTHING,
644 .arg4_type = ARG_PTR_TO_MEM | MEM_RDONLY,
645 .arg5_type = ARG_CONST_SIZE_OR_ZERO,
648 BPF_CALL_3(bpf_copy_from_user, void *, dst, u32, size,
649 const void __user *, user_ptr)
651 int ret = copy_from_user(dst, user_ptr, size);
654 memset(dst, 0, size);
661 const struct bpf_func_proto bpf_copy_from_user_proto = {
662 .func = bpf_copy_from_user,
665 .ret_type = RET_INTEGER,
666 .arg1_type = ARG_PTR_TO_UNINIT_MEM,
667 .arg2_type = ARG_CONST_SIZE_OR_ZERO,
668 .arg3_type = ARG_ANYTHING,
671 BPF_CALL_5(bpf_copy_from_user_task, void *, dst, u32, size,
672 const void __user *, user_ptr, struct task_struct *, tsk, u64, flags)
676 /* flags is not used yet */
683 ret = access_process_vm(tsk, (unsigned long)user_ptr, dst, size, 0);
687 memset(dst, 0, size);
688 /* Return -EFAULT for partial read */
689 return ret < 0 ? ret : -EFAULT;
692 const struct bpf_func_proto bpf_copy_from_user_task_proto = {
693 .func = bpf_copy_from_user_task,
696 .ret_type = RET_INTEGER,
697 .arg1_type = ARG_PTR_TO_UNINIT_MEM,
698 .arg2_type = ARG_CONST_SIZE_OR_ZERO,
699 .arg3_type = ARG_ANYTHING,
700 .arg4_type = ARG_PTR_TO_BTF_ID,
701 .arg4_btf_id = &btf_tracing_ids[BTF_TRACING_TYPE_TASK],
702 .arg5_type = ARG_ANYTHING
705 BPF_CALL_2(bpf_per_cpu_ptr, const void *, ptr, u32, cpu)
707 if (cpu >= nr_cpu_ids)
708 return (unsigned long)NULL;
710 return (unsigned long)per_cpu_ptr((const void __percpu *)ptr, cpu);
713 const struct bpf_func_proto bpf_per_cpu_ptr_proto = {
714 .func = bpf_per_cpu_ptr,
716 .ret_type = RET_PTR_TO_MEM_OR_BTF_ID | PTR_MAYBE_NULL | MEM_RDONLY,
717 .arg1_type = ARG_PTR_TO_PERCPU_BTF_ID,
718 .arg2_type = ARG_ANYTHING,
721 BPF_CALL_1(bpf_this_cpu_ptr, const void *, percpu_ptr)
723 return (unsigned long)this_cpu_ptr((const void __percpu *)percpu_ptr);
726 const struct bpf_func_proto bpf_this_cpu_ptr_proto = {
727 .func = bpf_this_cpu_ptr,
729 .ret_type = RET_PTR_TO_MEM_OR_BTF_ID | MEM_RDONLY,
730 .arg1_type = ARG_PTR_TO_PERCPU_BTF_ID,
733 static int bpf_trace_copy_string(char *buf, void *unsafe_ptr, char fmt_ptype,
736 void __user *user_ptr = (__force void __user *)unsafe_ptr;
742 #ifdef CONFIG_ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE
743 if ((unsigned long)unsafe_ptr < TASK_SIZE)
744 return strncpy_from_user_nofault(buf, user_ptr, bufsz);
748 return strncpy_from_kernel_nofault(buf, unsafe_ptr, bufsz);
750 return strncpy_from_user_nofault(buf, user_ptr, bufsz);
756 /* Per-cpu temp buffers used by printf-like helpers to store the bprintf binary
757 * arguments representation.
759 #define MAX_BPRINTF_BUF_LEN 512
761 /* Support executing three nested bprintf helper calls on a given CPU */
762 #define MAX_BPRINTF_NEST_LEVEL 3
763 struct bpf_bprintf_buffers {
764 char tmp_bufs[MAX_BPRINTF_NEST_LEVEL][MAX_BPRINTF_BUF_LEN];
766 static DEFINE_PER_CPU(struct bpf_bprintf_buffers, bpf_bprintf_bufs);
767 static DEFINE_PER_CPU(int, bpf_bprintf_nest_level);
769 static int try_get_fmt_tmp_buf(char **tmp_buf)
771 struct bpf_bprintf_buffers *bufs;
775 nest_level = this_cpu_inc_return(bpf_bprintf_nest_level);
776 if (WARN_ON_ONCE(nest_level > MAX_BPRINTF_NEST_LEVEL)) {
777 this_cpu_dec(bpf_bprintf_nest_level);
781 bufs = this_cpu_ptr(&bpf_bprintf_bufs);
782 *tmp_buf = bufs->tmp_bufs[nest_level - 1];
787 void bpf_bprintf_cleanup(void)
789 if (this_cpu_read(bpf_bprintf_nest_level)) {
790 this_cpu_dec(bpf_bprintf_nest_level);
796 * bpf_bprintf_prepare - Generic pass on format strings for bprintf-like helpers
798 * Returns a negative value if fmt is an invalid format string or 0 otherwise.
800 * This can be used in two ways:
801 * - Format string verification only: when bin_args is NULL
802 * - Arguments preparation: in addition to the above verification, it writes in
803 * bin_args a binary representation of arguments usable by bstr_printf where
804 * pointers from BPF have been sanitized.
806 * In argument preparation mode, if 0 is returned, safe temporary buffers are
807 * allocated and bpf_bprintf_cleanup should be called to free them after use.
809 int bpf_bprintf_prepare(char *fmt, u32 fmt_size, const u64 *raw_args,
810 u32 **bin_args, u32 num_args)
812 char *unsafe_ptr = NULL, *tmp_buf = NULL, *tmp_buf_end, *fmt_end;
813 size_t sizeof_cur_arg, sizeof_cur_ip;
814 int err, i, num_spec = 0;
816 char fmt_ptype, cur_ip[16], ip_spec[] = "%pXX";
818 fmt_end = strnchr(fmt, fmt_size, 0);
821 fmt_size = fmt_end - fmt;
824 if (num_args && try_get_fmt_tmp_buf(&tmp_buf))
827 tmp_buf_end = tmp_buf + MAX_BPRINTF_BUF_LEN;
828 *bin_args = (u32 *)tmp_buf;
831 for (i = 0; i < fmt_size; i++) {
832 if ((!isprint(fmt[i]) && !isspace(fmt[i])) || !isascii(fmt[i])) {
840 if (fmt[i + 1] == '%') {
845 if (num_spec >= num_args) {
850 /* The string is zero-terminated so if fmt[i] != 0, we can
851 * always access fmt[i + 1], in the worst case it will be a 0
855 /* skip optional "[0 +-][num]" width formatting field */
856 while (fmt[i] == '0' || fmt[i] == '+' || fmt[i] == '-' ||
859 if (fmt[i] >= '1' && fmt[i] <= '9') {
861 while (fmt[i] >= '0' && fmt[i] <= '9')
866 sizeof_cur_arg = sizeof(long);
868 if ((fmt[i + 1] == 'k' || fmt[i + 1] == 'u') &&
870 fmt_ptype = fmt[i + 1];
875 if (fmt[i + 1] == 0 || isspace(fmt[i + 1]) ||
876 ispunct(fmt[i + 1]) || fmt[i + 1] == 'K' ||
877 fmt[i + 1] == 'x' || fmt[i + 1] == 's' ||
879 /* just kernel pointers */
881 cur_arg = raw_args[num_spec];
886 if (fmt[i + 1] == 'B') {
888 err = snprintf(tmp_buf,
889 (tmp_buf_end - tmp_buf),
891 (void *)(long)raw_args[num_spec]);
892 tmp_buf += (err + 1);
900 /* only support "%pI4", "%pi4", "%pI6" and "%pi6". */
901 if ((fmt[i + 1] != 'i' && fmt[i + 1] != 'I') ||
902 (fmt[i + 2] != '4' && fmt[i + 2] != '6')) {
911 sizeof_cur_ip = (fmt[i] == '4') ? 4 : 16;
912 if (tmp_buf_end - tmp_buf < sizeof_cur_ip) {
917 unsafe_ptr = (char *)(long)raw_args[num_spec];
918 err = copy_from_kernel_nofault(cur_ip, unsafe_ptr,
921 memset(cur_ip, 0, sizeof_cur_ip);
923 /* hack: bstr_printf expects IP addresses to be
924 * pre-formatted as strings, ironically, the easiest way
925 * to do that is to call snprintf.
927 ip_spec[2] = fmt[i - 1];
929 err = snprintf(tmp_buf, tmp_buf_end - tmp_buf,
936 } else if (fmt[i] == 's') {
939 if (fmt[i + 1] != 0 &&
940 !isspace(fmt[i + 1]) &&
941 !ispunct(fmt[i + 1])) {
949 if (tmp_buf_end == tmp_buf) {
954 unsafe_ptr = (char *)(long)raw_args[num_spec];
955 err = bpf_trace_copy_string(tmp_buf, unsafe_ptr,
957 tmp_buf_end - tmp_buf);
967 } else if (fmt[i] == 'c') {
971 if (tmp_buf_end == tmp_buf) {
976 *tmp_buf = raw_args[num_spec];
983 sizeof_cur_arg = sizeof(int);
986 sizeof_cur_arg = sizeof(long);
990 sizeof_cur_arg = sizeof(long long);
994 if (fmt[i] != 'i' && fmt[i] != 'd' && fmt[i] != 'u' &&
995 fmt[i] != 'x' && fmt[i] != 'X') {
1001 cur_arg = raw_args[num_spec];
1004 tmp_buf = PTR_ALIGN(tmp_buf, sizeof(u32));
1005 if (tmp_buf_end - tmp_buf < sizeof_cur_arg) {
1010 if (sizeof_cur_arg == 8) {
1011 *(u32 *)tmp_buf = *(u32 *)&cur_arg;
1012 *(u32 *)(tmp_buf + 4) = *((u32 *)&cur_arg + 1);
1014 *(u32 *)tmp_buf = (u32)(long)cur_arg;
1016 tmp_buf += sizeof_cur_arg;
1024 bpf_bprintf_cleanup();
1028 BPF_CALL_5(bpf_snprintf, char *, str, u32, str_size, char *, fmt,
1029 const void *, data, u32, data_len)
1034 if (data_len % 8 || data_len > MAX_BPRINTF_VARARGS * 8 ||
1035 (data_len && !data))
1037 num_args = data_len / 8;
1039 /* ARG_PTR_TO_CONST_STR guarantees that fmt is zero-terminated so we
1040 * can safely give an unbounded size.
1042 err = bpf_bprintf_prepare(fmt, UINT_MAX, data, &bin_args, num_args);
1046 err = bstr_printf(str, str_size, fmt, bin_args);
1048 bpf_bprintf_cleanup();
1053 const struct bpf_func_proto bpf_snprintf_proto = {
1054 .func = bpf_snprintf,
1056 .ret_type = RET_INTEGER,
1057 .arg1_type = ARG_PTR_TO_MEM_OR_NULL,
1058 .arg2_type = ARG_CONST_SIZE_OR_ZERO,
1059 .arg3_type = ARG_PTR_TO_CONST_STR,
1060 .arg4_type = ARG_PTR_TO_MEM | PTR_MAYBE_NULL | MEM_RDONLY,
1061 .arg5_type = ARG_CONST_SIZE_OR_ZERO,
1064 /* BPF map elements can contain 'struct bpf_timer'.
1065 * Such map owns all of its BPF timers.
1066 * 'struct bpf_timer' is allocated as part of map element allocation
1067 * and it's zero initialized.
1068 * That space is used to keep 'struct bpf_timer_kern'.
1069 * bpf_timer_init() allocates 'struct bpf_hrtimer', inits hrtimer, and
1070 * remembers 'struct bpf_map *' pointer it's part of.
1071 * bpf_timer_set_callback() increments prog refcnt and assign bpf callback_fn.
1072 * bpf_timer_start() arms the timer.
1073 * If user space reference to a map goes to zero at this point
1074 * ops->map_release_uref callback is responsible for cancelling the timers,
1075 * freeing their memory, and decrementing prog's refcnts.
1076 * bpf_timer_cancel() cancels the timer and decrements prog's refcnt.
1077 * Inner maps can contain bpf timers as well. ops->map_release_uref is
1078 * freeing the timers when inner map is replaced or deleted by user space.
1080 struct bpf_hrtimer {
1081 struct hrtimer timer;
1082 struct bpf_map *map;
1083 struct bpf_prog *prog;
1084 void __rcu *callback_fn;
1088 /* the actual struct hidden inside uapi struct bpf_timer */
1089 struct bpf_timer_kern {
1090 struct bpf_hrtimer *timer;
1091 /* bpf_spin_lock is used here instead of spinlock_t to make
1092 * sure that it always fits into space reserved by struct bpf_timer
1093 * regardless of LOCKDEP and spinlock debug flags.
1095 struct bpf_spin_lock lock;
1096 } __attribute__((aligned(8)));
1098 static DEFINE_PER_CPU(struct bpf_hrtimer *, hrtimer_running);
1100 static enum hrtimer_restart bpf_timer_cb(struct hrtimer *hrtimer)
1102 struct bpf_hrtimer *t = container_of(hrtimer, struct bpf_hrtimer, timer);
1103 struct bpf_map *map = t->map;
1104 void *value = t->value;
1105 bpf_callback_t callback_fn;
1109 BTF_TYPE_EMIT(struct bpf_timer);
1110 callback_fn = rcu_dereference_check(t->callback_fn, rcu_read_lock_bh_held());
1114 /* bpf_timer_cb() runs in hrtimer_run_softirq. It doesn't migrate and
1115 * cannot be preempted by another bpf_timer_cb() on the same cpu.
1116 * Remember the timer this callback is servicing to prevent
1117 * deadlock if callback_fn() calls bpf_timer_cancel() or
1118 * bpf_map_delete_elem() on the same timer.
1120 this_cpu_write(hrtimer_running, t);
1121 if (map->map_type == BPF_MAP_TYPE_ARRAY) {
1122 struct bpf_array *array = container_of(map, struct bpf_array, map);
1124 /* compute the key */
1125 idx = ((char *)value - array->value) / array->elem_size;
1127 } else { /* hash or lru */
1128 key = value - round_up(map->key_size, 8);
1131 callback_fn((u64)(long)map, (u64)(long)key, (u64)(long)value, 0, 0);
1132 /* The verifier checked that return value is zero. */
1134 this_cpu_write(hrtimer_running, NULL);
1136 return HRTIMER_NORESTART;
1139 BPF_CALL_3(bpf_timer_init, struct bpf_timer_kern *, timer, struct bpf_map *, map,
1142 clockid_t clockid = flags & (MAX_CLOCKS - 1);
1143 struct bpf_hrtimer *t;
1146 BUILD_BUG_ON(MAX_CLOCKS != 16);
1147 BUILD_BUG_ON(sizeof(struct bpf_timer_kern) > sizeof(struct bpf_timer));
1148 BUILD_BUG_ON(__alignof__(struct bpf_timer_kern) != __alignof__(struct bpf_timer));
1153 if (flags >= MAX_CLOCKS ||
1154 /* similar to timerfd except _ALARM variants are not supported */
1155 (clockid != CLOCK_MONOTONIC &&
1156 clockid != CLOCK_REALTIME &&
1157 clockid != CLOCK_BOOTTIME))
1159 __bpf_spin_lock_irqsave(&timer->lock);
1165 if (!atomic64_read(&map->usercnt)) {
1166 /* maps with timers must be either held by user space
1167 * or pinned in bpffs.
1172 /* allocate hrtimer via map_kmalloc to use memcg accounting */
1173 t = bpf_map_kmalloc_node(map, sizeof(*t), GFP_ATOMIC, map->numa_node);
1178 t->value = (void *)timer - map->record->timer_off;
1181 rcu_assign_pointer(t->callback_fn, NULL);
1182 hrtimer_init(&t->timer, clockid, HRTIMER_MODE_REL_SOFT);
1183 t->timer.function = bpf_timer_cb;
1186 __bpf_spin_unlock_irqrestore(&timer->lock);
1190 static const struct bpf_func_proto bpf_timer_init_proto = {
1191 .func = bpf_timer_init,
1193 .ret_type = RET_INTEGER,
1194 .arg1_type = ARG_PTR_TO_TIMER,
1195 .arg2_type = ARG_CONST_MAP_PTR,
1196 .arg3_type = ARG_ANYTHING,
1199 BPF_CALL_3(bpf_timer_set_callback, struct bpf_timer_kern *, timer, void *, callback_fn,
1200 struct bpf_prog_aux *, aux)
1202 struct bpf_prog *prev, *prog = aux->prog;
1203 struct bpf_hrtimer *t;
1208 __bpf_spin_lock_irqsave(&timer->lock);
1214 if (!atomic64_read(&t->map->usercnt)) {
1215 /* maps with timers must be either held by user space
1216 * or pinned in bpffs. Otherwise timer might still be
1217 * running even when bpf prog is detached and user space
1218 * is gone, since map_release_uref won't ever be called.
1225 /* Bump prog refcnt once. Every bpf_timer_set_callback()
1226 * can pick different callback_fn-s within the same prog.
1228 prog = bpf_prog_inc_not_zero(prog);
1230 ret = PTR_ERR(prog);
1234 /* Drop prev prog refcnt when swapping with new prog */
1238 rcu_assign_pointer(t->callback_fn, callback_fn);
1240 __bpf_spin_unlock_irqrestore(&timer->lock);
1244 static const struct bpf_func_proto bpf_timer_set_callback_proto = {
1245 .func = bpf_timer_set_callback,
1247 .ret_type = RET_INTEGER,
1248 .arg1_type = ARG_PTR_TO_TIMER,
1249 .arg2_type = ARG_PTR_TO_FUNC,
1252 BPF_CALL_3(bpf_timer_start, struct bpf_timer_kern *, timer, u64, nsecs, u64, flags)
1254 struct bpf_hrtimer *t;
1261 __bpf_spin_lock_irqsave(&timer->lock);
1263 if (!t || !t->prog) {
1267 hrtimer_start(&t->timer, ns_to_ktime(nsecs), HRTIMER_MODE_REL_SOFT);
1269 __bpf_spin_unlock_irqrestore(&timer->lock);
1273 static const struct bpf_func_proto bpf_timer_start_proto = {
1274 .func = bpf_timer_start,
1276 .ret_type = RET_INTEGER,
1277 .arg1_type = ARG_PTR_TO_TIMER,
1278 .arg2_type = ARG_ANYTHING,
1279 .arg3_type = ARG_ANYTHING,
1282 static void drop_prog_refcnt(struct bpf_hrtimer *t)
1284 struct bpf_prog *prog = t->prog;
1289 rcu_assign_pointer(t->callback_fn, NULL);
1293 BPF_CALL_1(bpf_timer_cancel, struct bpf_timer_kern *, timer)
1295 struct bpf_hrtimer *t;
1300 __bpf_spin_lock_irqsave(&timer->lock);
1306 if (this_cpu_read(hrtimer_running) == t) {
1307 /* If bpf callback_fn is trying to bpf_timer_cancel()
1308 * its own timer the hrtimer_cancel() will deadlock
1309 * since it waits for callback_fn to finish
1314 drop_prog_refcnt(t);
1316 __bpf_spin_unlock_irqrestore(&timer->lock);
1317 /* Cancel the timer and wait for associated callback to finish
1318 * if it was running.
1320 ret = ret ?: hrtimer_cancel(&t->timer);
1324 static const struct bpf_func_proto bpf_timer_cancel_proto = {
1325 .func = bpf_timer_cancel,
1327 .ret_type = RET_INTEGER,
1328 .arg1_type = ARG_PTR_TO_TIMER,
1331 /* This function is called by map_delete/update_elem for individual element and
1332 * by ops->map_release_uref when the user space reference to a map reaches zero.
1334 void bpf_timer_cancel_and_free(void *val)
1336 struct bpf_timer_kern *timer = val;
1337 struct bpf_hrtimer *t;
1339 /* Performance optimization: read timer->timer without lock first. */
1340 if (!READ_ONCE(timer->timer))
1343 __bpf_spin_lock_irqsave(&timer->lock);
1344 /* re-read it under lock */
1348 drop_prog_refcnt(t);
1349 /* The subsequent bpf_timer_start/cancel() helpers won't be able to use
1350 * this timer, since it won't be initialized.
1352 timer->timer = NULL;
1354 __bpf_spin_unlock_irqrestore(&timer->lock);
1357 /* Cancel the timer and wait for callback to complete if it was running.
1358 * If hrtimer_cancel() can be safely called it's safe to call kfree(t)
1359 * right after for both preallocated and non-preallocated maps.
1360 * The timer->timer = NULL was already done and no code path can
1361 * see address 't' anymore.
1363 * Check that bpf_map_delete/update_elem() wasn't called from timer
1364 * callback_fn. In such case don't call hrtimer_cancel() (since it will
1365 * deadlock) and don't call hrtimer_try_to_cancel() (since it will just
1366 * return -1). Though callback_fn is still running on this cpu it's
1367 * safe to do kfree(t) because bpf_timer_cb() read everything it needed
1368 * from 't'. The bpf subprog callback_fn won't be able to access 't',
1369 * since timer->timer = NULL was already done. The timer will be
1370 * effectively cancelled because bpf_timer_cb() will return
1371 * HRTIMER_NORESTART.
1373 if (this_cpu_read(hrtimer_running) != t)
1374 hrtimer_cancel(&t->timer);
1378 BPF_CALL_2(bpf_kptr_xchg, void *, map_value, void *, ptr)
1380 unsigned long *kptr = map_value;
1382 return xchg(kptr, (unsigned long)ptr);
1385 /* Unlike other PTR_TO_BTF_ID helpers the btf_id in bpf_kptr_xchg()
1386 * helper is determined dynamically by the verifier. Use BPF_PTR_POISON to
1387 * denote type that verifier will determine.
1389 static const struct bpf_func_proto bpf_kptr_xchg_proto = {
1390 .func = bpf_kptr_xchg,
1392 .ret_type = RET_PTR_TO_BTF_ID_OR_NULL,
1393 .ret_btf_id = BPF_PTR_POISON,
1394 .arg1_type = ARG_PTR_TO_KPTR,
1395 .arg2_type = ARG_PTR_TO_BTF_ID_OR_NULL | OBJ_RELEASE,
1396 .arg2_btf_id = BPF_PTR_POISON,
1399 /* Since the upper 8 bits of dynptr->size is reserved, the
1400 * maximum supported size is 2^24 - 1.
1402 #define DYNPTR_MAX_SIZE ((1UL << 24) - 1)
1403 #define DYNPTR_TYPE_SHIFT 28
1404 #define DYNPTR_SIZE_MASK 0xFFFFFF
1405 #define DYNPTR_RDONLY_BIT BIT(31)
1407 static bool bpf_dynptr_is_rdonly(const struct bpf_dynptr_kern *ptr)
1409 return ptr->size & DYNPTR_RDONLY_BIT;
1412 static void bpf_dynptr_set_type(struct bpf_dynptr_kern *ptr, enum bpf_dynptr_type type)
1414 ptr->size |= type << DYNPTR_TYPE_SHIFT;
1417 u32 bpf_dynptr_get_size(const struct bpf_dynptr_kern *ptr)
1419 return ptr->size & DYNPTR_SIZE_MASK;
1422 int bpf_dynptr_check_size(u32 size)
1424 return size > DYNPTR_MAX_SIZE ? -E2BIG : 0;
1427 void bpf_dynptr_init(struct bpf_dynptr_kern *ptr, void *data,
1428 enum bpf_dynptr_type type, u32 offset, u32 size)
1431 ptr->offset = offset;
1433 bpf_dynptr_set_type(ptr, type);
1436 void bpf_dynptr_set_null(struct bpf_dynptr_kern *ptr)
1438 memset(ptr, 0, sizeof(*ptr));
1441 static int bpf_dynptr_check_off_len(const struct bpf_dynptr_kern *ptr, u32 offset, u32 len)
1443 u32 size = bpf_dynptr_get_size(ptr);
1445 if (len > size || offset > size - len)
1451 BPF_CALL_4(bpf_dynptr_from_mem, void *, data, u32, size, u64, flags, struct bpf_dynptr_kern *, ptr)
1455 BTF_TYPE_EMIT(struct bpf_dynptr);
1457 err = bpf_dynptr_check_size(size);
1461 /* flags is currently unsupported */
1467 bpf_dynptr_init(ptr, data, BPF_DYNPTR_TYPE_LOCAL, 0, size);
1472 bpf_dynptr_set_null(ptr);
1476 static const struct bpf_func_proto bpf_dynptr_from_mem_proto = {
1477 .func = bpf_dynptr_from_mem,
1479 .ret_type = RET_INTEGER,
1480 .arg1_type = ARG_PTR_TO_UNINIT_MEM,
1481 .arg2_type = ARG_CONST_SIZE_OR_ZERO,
1482 .arg3_type = ARG_ANYTHING,
1483 .arg4_type = ARG_PTR_TO_DYNPTR | DYNPTR_TYPE_LOCAL | MEM_UNINIT,
1486 BPF_CALL_5(bpf_dynptr_read, void *, dst, u32, len, const struct bpf_dynptr_kern *, src,
1487 u32, offset, u64, flags)
1491 if (!src->data || flags)
1494 err = bpf_dynptr_check_off_len(src, offset, len);
1498 /* Source and destination may possibly overlap, hence use memmove to
1499 * copy the data. E.g. bpf_dynptr_from_mem may create two dynptr
1500 * pointing to overlapping PTR_TO_MAP_VALUE regions.
1502 memmove(dst, src->data + src->offset + offset, len);
1507 static const struct bpf_func_proto bpf_dynptr_read_proto = {
1508 .func = bpf_dynptr_read,
1510 .ret_type = RET_INTEGER,
1511 .arg1_type = ARG_PTR_TO_UNINIT_MEM,
1512 .arg2_type = ARG_CONST_SIZE_OR_ZERO,
1513 .arg3_type = ARG_PTR_TO_DYNPTR | MEM_RDONLY,
1514 .arg4_type = ARG_ANYTHING,
1515 .arg5_type = ARG_ANYTHING,
1518 BPF_CALL_5(bpf_dynptr_write, const struct bpf_dynptr_kern *, dst, u32, offset, void *, src,
1519 u32, len, u64, flags)
1523 if (!dst->data || flags || bpf_dynptr_is_rdonly(dst))
1526 err = bpf_dynptr_check_off_len(dst, offset, len);
1530 /* Source and destination may possibly overlap, hence use memmove to
1531 * copy the data. E.g. bpf_dynptr_from_mem may create two dynptr
1532 * pointing to overlapping PTR_TO_MAP_VALUE regions.
1534 memmove(dst->data + dst->offset + offset, src, len);
1539 static const struct bpf_func_proto bpf_dynptr_write_proto = {
1540 .func = bpf_dynptr_write,
1542 .ret_type = RET_INTEGER,
1543 .arg1_type = ARG_PTR_TO_DYNPTR | MEM_RDONLY,
1544 .arg2_type = ARG_ANYTHING,
1545 .arg3_type = ARG_PTR_TO_MEM | MEM_RDONLY,
1546 .arg4_type = ARG_CONST_SIZE_OR_ZERO,
1547 .arg5_type = ARG_ANYTHING,
1550 BPF_CALL_3(bpf_dynptr_data, const struct bpf_dynptr_kern *, ptr, u32, offset, u32, len)
1557 err = bpf_dynptr_check_off_len(ptr, offset, len);
1561 if (bpf_dynptr_is_rdonly(ptr))
1564 return (unsigned long)(ptr->data + ptr->offset + offset);
1567 static const struct bpf_func_proto bpf_dynptr_data_proto = {
1568 .func = bpf_dynptr_data,
1570 .ret_type = RET_PTR_TO_DYNPTR_MEM_OR_NULL,
1571 .arg1_type = ARG_PTR_TO_DYNPTR | MEM_RDONLY,
1572 .arg2_type = ARG_ANYTHING,
1573 .arg3_type = ARG_CONST_ALLOC_SIZE_OR_ZERO,
1576 const struct bpf_func_proto bpf_get_current_task_proto __weak;
1577 const struct bpf_func_proto bpf_get_current_task_btf_proto __weak;
1578 const struct bpf_func_proto bpf_probe_read_user_proto __weak;
1579 const struct bpf_func_proto bpf_probe_read_user_str_proto __weak;
1580 const struct bpf_func_proto bpf_probe_read_kernel_proto __weak;
1581 const struct bpf_func_proto bpf_probe_read_kernel_str_proto __weak;
1582 const struct bpf_func_proto bpf_task_pt_regs_proto __weak;
1584 const struct bpf_func_proto *
1585 bpf_base_func_proto(enum bpf_func_id func_id)
1588 case BPF_FUNC_map_lookup_elem:
1589 return &bpf_map_lookup_elem_proto;
1590 case BPF_FUNC_map_update_elem:
1591 return &bpf_map_update_elem_proto;
1592 case BPF_FUNC_map_delete_elem:
1593 return &bpf_map_delete_elem_proto;
1594 case BPF_FUNC_map_push_elem:
1595 return &bpf_map_push_elem_proto;
1596 case BPF_FUNC_map_pop_elem:
1597 return &bpf_map_pop_elem_proto;
1598 case BPF_FUNC_map_peek_elem:
1599 return &bpf_map_peek_elem_proto;
1600 case BPF_FUNC_map_lookup_percpu_elem:
1601 return &bpf_map_lookup_percpu_elem_proto;
1602 case BPF_FUNC_get_prandom_u32:
1603 return &bpf_get_prandom_u32_proto;
1604 case BPF_FUNC_get_smp_processor_id:
1605 return &bpf_get_raw_smp_processor_id_proto;
1606 case BPF_FUNC_get_numa_node_id:
1607 return &bpf_get_numa_node_id_proto;
1608 case BPF_FUNC_tail_call:
1609 return &bpf_tail_call_proto;
1610 case BPF_FUNC_ktime_get_ns:
1611 return &bpf_ktime_get_ns_proto;
1612 case BPF_FUNC_ktime_get_boot_ns:
1613 return &bpf_ktime_get_boot_ns_proto;
1614 case BPF_FUNC_ktime_get_tai_ns:
1615 return &bpf_ktime_get_tai_ns_proto;
1616 case BPF_FUNC_ringbuf_output:
1617 return &bpf_ringbuf_output_proto;
1618 case BPF_FUNC_ringbuf_reserve:
1619 return &bpf_ringbuf_reserve_proto;
1620 case BPF_FUNC_ringbuf_submit:
1621 return &bpf_ringbuf_submit_proto;
1622 case BPF_FUNC_ringbuf_discard:
1623 return &bpf_ringbuf_discard_proto;
1624 case BPF_FUNC_ringbuf_query:
1625 return &bpf_ringbuf_query_proto;
1626 case BPF_FUNC_strncmp:
1627 return &bpf_strncmp_proto;
1628 case BPF_FUNC_strtol:
1629 return &bpf_strtol_proto;
1630 case BPF_FUNC_strtoul:
1631 return &bpf_strtoul_proto;
1640 case BPF_FUNC_spin_lock:
1641 return &bpf_spin_lock_proto;
1642 case BPF_FUNC_spin_unlock:
1643 return &bpf_spin_unlock_proto;
1644 case BPF_FUNC_jiffies64:
1645 return &bpf_jiffies64_proto;
1646 case BPF_FUNC_per_cpu_ptr:
1647 return &bpf_per_cpu_ptr_proto;
1648 case BPF_FUNC_this_cpu_ptr:
1649 return &bpf_this_cpu_ptr_proto;
1650 case BPF_FUNC_timer_init:
1651 return &bpf_timer_init_proto;
1652 case BPF_FUNC_timer_set_callback:
1653 return &bpf_timer_set_callback_proto;
1654 case BPF_FUNC_timer_start:
1655 return &bpf_timer_start_proto;
1656 case BPF_FUNC_timer_cancel:
1657 return &bpf_timer_cancel_proto;
1658 case BPF_FUNC_kptr_xchg:
1659 return &bpf_kptr_xchg_proto;
1660 case BPF_FUNC_for_each_map_elem:
1661 return &bpf_for_each_map_elem_proto;
1663 return &bpf_loop_proto;
1664 case BPF_FUNC_user_ringbuf_drain:
1665 return &bpf_user_ringbuf_drain_proto;
1666 case BPF_FUNC_ringbuf_reserve_dynptr:
1667 return &bpf_ringbuf_reserve_dynptr_proto;
1668 case BPF_FUNC_ringbuf_submit_dynptr:
1669 return &bpf_ringbuf_submit_dynptr_proto;
1670 case BPF_FUNC_ringbuf_discard_dynptr:
1671 return &bpf_ringbuf_discard_dynptr_proto;
1672 case BPF_FUNC_dynptr_from_mem:
1673 return &bpf_dynptr_from_mem_proto;
1674 case BPF_FUNC_dynptr_read:
1675 return &bpf_dynptr_read_proto;
1676 case BPF_FUNC_dynptr_write:
1677 return &bpf_dynptr_write_proto;
1678 case BPF_FUNC_dynptr_data:
1679 return &bpf_dynptr_data_proto;
1680 #ifdef CONFIG_CGROUPS
1681 case BPF_FUNC_cgrp_storage_get:
1682 return &bpf_cgrp_storage_get_proto;
1683 case BPF_FUNC_cgrp_storage_delete:
1684 return &bpf_cgrp_storage_delete_proto;
1690 if (!perfmon_capable())
1694 case BPF_FUNC_trace_printk:
1695 return bpf_get_trace_printk_proto();
1696 case BPF_FUNC_get_current_task:
1697 return &bpf_get_current_task_proto;
1698 case BPF_FUNC_get_current_task_btf:
1699 return &bpf_get_current_task_btf_proto;
1700 case BPF_FUNC_probe_read_user:
1701 return &bpf_probe_read_user_proto;
1702 case BPF_FUNC_probe_read_kernel:
1703 return security_locked_down(LOCKDOWN_BPF_READ_KERNEL) < 0 ?
1704 NULL : &bpf_probe_read_kernel_proto;
1705 case BPF_FUNC_probe_read_user_str:
1706 return &bpf_probe_read_user_str_proto;
1707 case BPF_FUNC_probe_read_kernel_str:
1708 return security_locked_down(LOCKDOWN_BPF_READ_KERNEL) < 0 ?
1709 NULL : &bpf_probe_read_kernel_str_proto;
1710 case BPF_FUNC_snprintf_btf:
1711 return &bpf_snprintf_btf_proto;
1712 case BPF_FUNC_snprintf:
1713 return &bpf_snprintf_proto;
1714 case BPF_FUNC_task_pt_regs:
1715 return &bpf_task_pt_regs_proto;
1716 case BPF_FUNC_trace_vprintk:
1717 return bpf_get_trace_vprintk_proto();
1723 void bpf_list_head_free(const struct btf_field *field, void *list_head,
1724 struct bpf_spin_lock *spin_lock)
1726 struct list_head *head = list_head, *orig_head = list_head;
1728 BUILD_BUG_ON(sizeof(struct list_head) > sizeof(struct bpf_list_head));
1729 BUILD_BUG_ON(__alignof__(struct list_head) > __alignof__(struct bpf_list_head));
1731 /* Do the actual list draining outside the lock to not hold the lock for
1732 * too long, and also prevent deadlocks if tracing programs end up
1733 * executing on entry/exit of functions called inside the critical
1734 * section, and end up doing map ops that call bpf_list_head_free for
1735 * the same map value again.
1737 __bpf_spin_lock_irqsave(spin_lock);
1738 if (!head->next || list_empty(head))
1742 INIT_LIST_HEAD(orig_head);
1743 __bpf_spin_unlock_irqrestore(spin_lock);
1745 while (head != orig_head) {
1748 obj -= field->list_head.node_offset;
1750 /* The contained type can also have resources, including a
1751 * bpf_list_head which needs to be freed.
1753 bpf_obj_free_fields(field->list_head.value_rec, obj);
1754 /* bpf_mem_free requires migrate_disable(), since we can be
1755 * called from map free path as well apart from BPF program (as
1756 * part of map ops doing bpf_obj_free_fields).
1759 bpf_mem_free(&bpf_global_ma, obj);
1765 __diag_ignore_all("-Wmissing-prototypes",
1766 "Global functions as their definitions will be in vmlinux BTF");
1768 void *bpf_obj_new_impl(u64 local_type_id__k, void *meta__ign)
1770 struct btf_struct_meta *meta = meta__ign;
1771 u64 size = local_type_id__k;
1774 p = bpf_mem_alloc(&bpf_global_ma, size);
1778 bpf_obj_init(meta->field_offs, p);
1782 void bpf_obj_drop_impl(void *p__alloc, void *meta__ign)
1784 struct btf_struct_meta *meta = meta__ign;
1788 bpf_obj_free_fields(meta->record, p);
1789 bpf_mem_free(&bpf_global_ma, p);
1792 static void __bpf_list_add(struct bpf_list_node *node, struct bpf_list_head *head, bool tail)
1794 struct list_head *n = (void *)node, *h = (void *)head;
1796 if (unlikely(!h->next))
1798 if (unlikely(!n->next))
1800 tail ? list_add_tail(n, h) : list_add(n, h);
1803 void bpf_list_push_front(struct bpf_list_head *head, struct bpf_list_node *node)
1805 return __bpf_list_add(node, head, false);
1808 void bpf_list_push_back(struct bpf_list_head *head, struct bpf_list_node *node)
1810 return __bpf_list_add(node, head, true);
1813 static struct bpf_list_node *__bpf_list_del(struct bpf_list_head *head, bool tail)
1815 struct list_head *n, *h = (void *)head;
1817 if (unlikely(!h->next))
1821 n = tail ? h->prev : h->next;
1823 return (struct bpf_list_node *)n;
1826 struct bpf_list_node *bpf_list_pop_front(struct bpf_list_head *head)
1828 return __bpf_list_del(head, false);
1831 struct bpf_list_node *bpf_list_pop_back(struct bpf_list_head *head)
1833 return __bpf_list_del(head, true);
1837 * bpf_task_acquire - Acquire a reference to a task. A task acquired by this
1838 * kfunc which is not stored in a map as a kptr, must be released by calling
1839 * bpf_task_release().
1840 * @p: The task on which a reference is being acquired.
1842 struct task_struct *bpf_task_acquire(struct task_struct *p)
1844 return get_task_struct(p);
1848 * bpf_task_acquire_not_zero - Acquire a reference to a rcu task object. A task
1849 * acquired by this kfunc which is not stored in a map as a kptr, must be
1850 * released by calling bpf_task_release().
1851 * @p: The task on which a reference is being acquired.
1853 struct task_struct *bpf_task_acquire_not_zero(struct task_struct *p)
1855 /* For the time being this function returns NULL, as it's not currently
1856 * possible to safely acquire a reference to a task with RCU protection
1857 * using get_task_struct() and put_task_struct(). This is due to the
1858 * slightly odd mechanics of p->rcu_users, and how task RCU protection
1861 * A struct task_struct is refcounted by two different refcount_t
1864 * 1. p->usage: The "true" refcount field which tracks a task's
1865 * lifetime. The task is freed as soon as this
1866 * refcount drops to 0.
1868 * 2. p->rcu_users: An "RCU users" refcount field which is statically
1869 * initialized to 2, and is co-located in a union with
1870 * a struct rcu_head field (p->rcu). p->rcu_users
1871 * essentially encapsulates a single p->usage
1872 * refcount, and when p->rcu_users goes to 0, an RCU
1873 * callback is scheduled on the struct rcu_head which
1874 * decrements the p->usage refcount.
1876 * There are two important implications to this task refcounting logic
1877 * described above. The first is that
1878 * refcount_inc_not_zero(&p->rcu_users) cannot be used anywhere, as
1879 * after the refcount goes to 0, the RCU callback being scheduled will
1880 * cause the memory backing the refcount to again be nonzero due to the
1881 * fields sharing a union. The other is that we can't rely on RCU to
1882 * guarantee that a task is valid in a BPF program. This is because a
1883 * task could have already transitioned to being in the TASK_DEAD
1884 * state, had its rcu_users refcount go to 0, and its rcu callback
1885 * invoked in which it drops its single p->usage reference. At this
1886 * point the task will be freed as soon as the last p->usage reference
1887 * goes to 0, without waiting for another RCU gp to elapse. The only
1888 * way that a BPF program can guarantee that a task is valid is in this
1889 * scenario is to hold a p->usage refcount itself.
1891 * Until we're able to resolve this issue, either by pulling
1892 * p->rcu_users and p->rcu out of the union, or by getting rid of
1893 * p->usage and just using p->rcu_users for refcounting, we'll just
1900 * bpf_task_kptr_get - Acquire a reference on a struct task_struct kptr. A task
1901 * kptr acquired by this kfunc which is not subsequently stored in a map, must
1902 * be released by calling bpf_task_release().
1903 * @pp: A pointer to a task kptr on which a reference is being acquired.
1905 struct task_struct *bpf_task_kptr_get(struct task_struct **pp)
1907 /* We must return NULL here until we have clarity on how to properly
1908 * leverage RCU for ensuring a task's lifetime. See the comment above
1909 * in bpf_task_acquire_not_zero() for more details.
1915 * bpf_task_release - Release the reference acquired on a task.
1916 * @p: The task on which a reference is being released.
1918 void bpf_task_release(struct task_struct *p)
1926 #ifdef CONFIG_CGROUPS
1928 * bpf_cgroup_acquire - Acquire a reference to a cgroup. A cgroup acquired by
1929 * this kfunc which is not stored in a map as a kptr, must be released by
1930 * calling bpf_cgroup_release().
1931 * @cgrp: The cgroup on which a reference is being acquired.
1933 struct cgroup *bpf_cgroup_acquire(struct cgroup *cgrp)
1940 * bpf_cgroup_kptr_get - Acquire a reference on a struct cgroup kptr. A cgroup
1941 * kptr acquired by this kfunc which is not subsequently stored in a map, must
1942 * be released by calling bpf_cgroup_release().
1943 * @cgrpp: A pointer to a cgroup kptr on which a reference is being acquired.
1945 struct cgroup *bpf_cgroup_kptr_get(struct cgroup **cgrpp)
1947 struct cgroup *cgrp;
1950 /* Another context could remove the cgroup from the map and release it
1951 * at any time, including after we've done the lookup above. This is
1952 * safe because we're in an RCU read region, so the cgroup is
1953 * guaranteed to remain valid until at least the rcu_read_unlock()
1956 cgrp = READ_ONCE(*cgrpp);
1958 if (cgrp && !cgroup_tryget(cgrp))
1959 /* If the cgroup had been removed from the map and freed as
1960 * described above, cgroup_tryget() will return false. The
1961 * cgroup will be freed at some point after the current RCU gp
1962 * has ended, so just return NULL to the user.
1971 * bpf_cgroup_release - Release the reference acquired on a cgroup.
1972 * If this kfunc is invoked in an RCU read region, the cgroup is guaranteed to
1973 * not be freed until the current grace period has ended, even if its refcount
1975 * @cgrp: The cgroup on which a reference is being released.
1977 void bpf_cgroup_release(struct cgroup *cgrp)
1986 * bpf_cgroup_ancestor - Perform a lookup on an entry in a cgroup's ancestor
1987 * array. A cgroup returned by this kfunc which is not subsequently stored in a
1988 * map, must be released by calling bpf_cgroup_release().
1989 * @cgrp: The cgroup for which we're performing a lookup.
1990 * @level: The level of ancestor to look up.
1992 struct cgroup *bpf_cgroup_ancestor(struct cgroup *cgrp, int level)
1994 struct cgroup *ancestor;
1996 if (level > cgrp->level || level < 0)
1999 ancestor = cgrp->ancestors[level];
2000 cgroup_get(ancestor);
2003 #endif /* CONFIG_CGROUPS */
2006 * bpf_task_from_pid - Find a struct task_struct from its pid by looking it up
2007 * in the root pid namespace idr. If a task is returned, it must either be
2008 * stored in a map, or released with bpf_task_release().
2009 * @pid: The pid of the task being looked up.
2011 struct task_struct *bpf_task_from_pid(s32 pid)
2013 struct task_struct *p;
2016 p = find_task_by_pid_ns(pid, &init_pid_ns);
2018 bpf_task_acquire(p);
2024 void *bpf_cast_to_kern_ctx(void *obj)
2029 void *bpf_rdonly_cast(void *obj__ign, u32 btf_id__k)
2034 void bpf_rcu_read_lock(void)
2039 void bpf_rcu_read_unlock(void)
2046 BTF_SET8_START(generic_btf_ids)
2047 #ifdef CONFIG_KEXEC_CORE
2048 BTF_ID_FLAGS(func, crash_kexec, KF_DESTRUCTIVE)
2050 BTF_ID_FLAGS(func, bpf_obj_new_impl, KF_ACQUIRE | KF_RET_NULL)
2051 BTF_ID_FLAGS(func, bpf_obj_drop_impl, KF_RELEASE)
2052 BTF_ID_FLAGS(func, bpf_list_push_front)
2053 BTF_ID_FLAGS(func, bpf_list_push_back)
2054 BTF_ID_FLAGS(func, bpf_list_pop_front, KF_ACQUIRE | KF_RET_NULL)
2055 BTF_ID_FLAGS(func, bpf_list_pop_back, KF_ACQUIRE | KF_RET_NULL)
2056 BTF_ID_FLAGS(func, bpf_task_acquire, KF_ACQUIRE | KF_TRUSTED_ARGS)
2057 BTF_ID_FLAGS(func, bpf_task_acquire_not_zero, KF_ACQUIRE | KF_RCU | KF_RET_NULL)
2058 BTF_ID_FLAGS(func, bpf_task_kptr_get, KF_ACQUIRE | KF_KPTR_GET | KF_RET_NULL)
2059 BTF_ID_FLAGS(func, bpf_task_release, KF_RELEASE)
2060 #ifdef CONFIG_CGROUPS
2061 BTF_ID_FLAGS(func, bpf_cgroup_acquire, KF_ACQUIRE | KF_TRUSTED_ARGS)
2062 BTF_ID_FLAGS(func, bpf_cgroup_kptr_get, KF_ACQUIRE | KF_KPTR_GET | KF_RET_NULL)
2063 BTF_ID_FLAGS(func, bpf_cgroup_release, KF_RELEASE)
2064 BTF_ID_FLAGS(func, bpf_cgroup_ancestor, KF_ACQUIRE | KF_TRUSTED_ARGS | KF_RET_NULL)
2066 BTF_ID_FLAGS(func, bpf_task_from_pid, KF_ACQUIRE | KF_RET_NULL)
2067 BTF_SET8_END(generic_btf_ids)
2069 static const struct btf_kfunc_id_set generic_kfunc_set = {
2070 .owner = THIS_MODULE,
2071 .set = &generic_btf_ids,
2075 BTF_ID_LIST(generic_dtor_ids)
2076 BTF_ID(struct, task_struct)
2077 BTF_ID(func, bpf_task_release)
2078 #ifdef CONFIG_CGROUPS
2079 BTF_ID(struct, cgroup)
2080 BTF_ID(func, bpf_cgroup_release)
2083 BTF_SET8_START(common_btf_ids)
2084 BTF_ID_FLAGS(func, bpf_cast_to_kern_ctx)
2085 BTF_ID_FLAGS(func, bpf_rdonly_cast)
2086 BTF_ID_FLAGS(func, bpf_rcu_read_lock)
2087 BTF_ID_FLAGS(func, bpf_rcu_read_unlock)
2088 BTF_SET8_END(common_btf_ids)
2090 static const struct btf_kfunc_id_set common_kfunc_set = {
2091 .owner = THIS_MODULE,
2092 .set = &common_btf_ids,
2095 static int __init kfunc_init(void)
2098 const struct btf_id_dtor_kfunc generic_dtors[] = {
2100 .btf_id = generic_dtor_ids[0],
2101 .kfunc_btf_id = generic_dtor_ids[1]
2103 #ifdef CONFIG_CGROUPS
2105 .btf_id = generic_dtor_ids[2],
2106 .kfunc_btf_id = generic_dtor_ids[3]
2111 ret = register_btf_kfunc_id_set(BPF_PROG_TYPE_TRACING, &generic_kfunc_set);
2112 ret = ret ?: register_btf_kfunc_id_set(BPF_PROG_TYPE_SCHED_CLS, &generic_kfunc_set);
2113 ret = ret ?: register_btf_kfunc_id_set(BPF_PROG_TYPE_STRUCT_OPS, &generic_kfunc_set);
2114 ret = ret ?: register_btf_id_dtor_kfuncs(generic_dtors,
2115 ARRAY_SIZE(generic_dtors),
2117 return ret ?: register_btf_kfunc_id_set(BPF_PROG_TYPE_UNSPEC, &common_kfunc_set);
2120 late_initcall(kfunc_init);