diff options
Diffstat (limited to 'kernel/bpf')
| -rw-r--r-- | kernel/bpf/Makefile | 2 | ||||
| -rw-r--r-- | kernel/bpf/arraymap.c | 38 | ||||
| -rw-r--r-- | kernel/bpf/bpf_insn_array.c | 304 | ||||
| -rw-r--r-- | kernel/bpf/bpf_local_storage.c | 235 | ||||
| -rw-r--r-- | kernel/bpf/bpf_lsm.c | 1 | ||||
| -rw-r--r-- | kernel/bpf/core.c | 26 | ||||
| -rw-r--r-- | kernel/bpf/disasm.c | 3 | ||||
| -rw-r--r-- | kernel/bpf/hashtab.c | 67 | ||||
| -rw-r--r-- | kernel/bpf/helpers.c | 296 | ||||
| -rw-r--r-- | kernel/bpf/liveness.c | 42 | ||||
| -rw-r--r-- | kernel/bpf/log.c | 3 | ||||
| -rw-r--r-- | kernel/bpf/range_tree.c | 21 | ||||
| -rw-r--r-- | kernel/bpf/ringbuf.c | 114 | ||||
| -rw-r--r-- | kernel/bpf/rqspinlock.c | 90 | ||||
| -rw-r--r-- | kernel/bpf/stackmap.c | 62 | ||||
| -rw-r--r-- | kernel/bpf/stream.c | 159 | ||||
| -rw-r--r-- | kernel/bpf/syscall.c | 86 | ||||
| -rw-r--r-- | kernel/bpf/trampoline.c | 83 | ||||
| -rw-r--r-- | kernel/bpf/verifier.c | 983 |
19 files changed, 1819 insertions, 796 deletions
diff --git a/kernel/bpf/Makefile b/kernel/bpf/Makefile index 7fd0badfacb1..232cbc97434d 100644 --- a/kernel/bpf/Makefile +++ b/kernel/bpf/Makefile @@ -9,7 +9,7 @@ CFLAGS_core.o += -Wno-override-init $(cflags-nogcse-yy) obj-$(CONFIG_BPF_SYSCALL) += syscall.o verifier.o inode.o helpers.o tnum.o log.o token.o liveness.o obj-$(CONFIG_BPF_SYSCALL) += bpf_iter.o map_iter.o task_iter.o prog_iter.o link_iter.o obj-$(CONFIG_BPF_SYSCALL) += hashtab.o arraymap.o percpu_freelist.o bpf_lru_list.o lpm_trie.o map_in_map.o bloom_filter.o -obj-$(CONFIG_BPF_SYSCALL) += local_storage.o queue_stack_maps.o ringbuf.o +obj-$(CONFIG_BPF_SYSCALL) += local_storage.o queue_stack_maps.o ringbuf.o bpf_insn_array.o obj-$(CONFIG_BPF_SYSCALL) += bpf_local_storage.o bpf_task_storage.o obj-${CONFIG_BPF_LSM} += bpf_inode_storage.o obj-$(CONFIG_BPF_SYSCALL) += disasm.o mprog.o diff --git a/kernel/bpf/arraymap.c b/kernel/bpf/arraymap.c index 80b1765a3159..1eeb31c5b317 100644 --- a/kernel/bpf/arraymap.c +++ b/kernel/bpf/arraymap.c @@ -335,18 +335,17 @@ int bpf_percpu_array_copy(struct bpf_map *map, void *key, void *value) } /* Called from syscall */ -static int array_map_get_next_key(struct bpf_map *map, void *key, void *next_key) +int bpf_array_get_next_key(struct bpf_map *map, void *key, void *next_key) { - struct bpf_array *array = container_of(map, struct bpf_array, map); u32 index = key ? *(u32 *)key : U32_MAX; u32 *next = (u32 *)next_key; - if (index >= array->map.max_entries) { + if (index >= map->max_entries) { *next = 0; return 0; } - if (index == array->map.max_entries - 1) + if (index == map->max_entries - 1) return -ENOENT; *next = index + 1; @@ -448,19 +447,12 @@ static void array_map_free_internal_structs(struct bpf_map *map) struct bpf_array *array = container_of(map, struct bpf_array, map); int i; - /* We don't reset or free fields other than timer and workqueue - * on uref dropping to zero. - */ - if (btf_record_has_field(map->record, BPF_TIMER | BPF_WORKQUEUE | BPF_TASK_WORK)) { - for (i = 0; i < array->map.max_entries; i++) { - if (btf_record_has_field(map->record, BPF_TIMER)) - bpf_obj_free_timer(map->record, array_map_elem_ptr(array, i)); - if (btf_record_has_field(map->record, BPF_WORKQUEUE)) - bpf_obj_free_workqueue(map->record, array_map_elem_ptr(array, i)); - if (btf_record_has_field(map->record, BPF_TASK_WORK)) - bpf_obj_free_task_work(map->record, array_map_elem_ptr(array, i)); - } - } + /* We only free internal structs on uref dropping to zero */ + if (!bpf_map_has_internal_structs(map)) + return; + + for (i = 0; i < array->map.max_entries; i++) + bpf_map_free_internal_structs(map, array_map_elem_ptr(array, i)); } /* Called when map->refcnt goes to zero, either from workqueue or from syscall */ @@ -796,7 +788,7 @@ const struct bpf_map_ops array_map_ops = { .map_alloc_check = array_map_alloc_check, .map_alloc = array_map_alloc, .map_free = array_map_free, - .map_get_next_key = array_map_get_next_key, + .map_get_next_key = bpf_array_get_next_key, .map_release_uref = array_map_free_internal_structs, .map_lookup_elem = array_map_lookup_elem, .map_update_elem = array_map_update_elem, @@ -822,7 +814,7 @@ const struct bpf_map_ops percpu_array_map_ops = { .map_alloc_check = array_map_alloc_check, .map_alloc = array_map_alloc, .map_free = array_map_free, - .map_get_next_key = array_map_get_next_key, + .map_get_next_key = bpf_array_get_next_key, .map_lookup_elem = percpu_array_map_lookup_elem, .map_gen_lookup = percpu_array_map_gen_lookup, .map_update_elem = array_map_update_elem, @@ -1211,7 +1203,7 @@ const struct bpf_map_ops prog_array_map_ops = { .map_poke_track = prog_array_map_poke_track, .map_poke_untrack = prog_array_map_poke_untrack, .map_poke_run = prog_array_map_poke_run, - .map_get_next_key = array_map_get_next_key, + .map_get_next_key = bpf_array_get_next_key, .map_lookup_elem = fd_array_map_lookup_elem, .map_delete_elem = fd_array_map_delete_elem, .map_fd_get_ptr = prog_fd_array_get_ptr, @@ -1315,7 +1307,7 @@ const struct bpf_map_ops perf_event_array_map_ops = { .map_alloc_check = fd_array_map_alloc_check, .map_alloc = array_map_alloc, .map_free = perf_event_fd_array_map_free, - .map_get_next_key = array_map_get_next_key, + .map_get_next_key = bpf_array_get_next_key, .map_lookup_elem = fd_array_map_lookup_elem, .map_delete_elem = fd_array_map_delete_elem, .map_fd_get_ptr = perf_event_fd_array_get_ptr, @@ -1351,7 +1343,7 @@ const struct bpf_map_ops cgroup_array_map_ops = { .map_alloc_check = fd_array_map_alloc_check, .map_alloc = array_map_alloc, .map_free = cgroup_fd_array_free, - .map_get_next_key = array_map_get_next_key, + .map_get_next_key = bpf_array_get_next_key, .map_lookup_elem = fd_array_map_lookup_elem, .map_delete_elem = fd_array_map_delete_elem, .map_fd_get_ptr = cgroup_fd_array_get_ptr, @@ -1436,7 +1428,7 @@ const struct bpf_map_ops array_of_maps_map_ops = { .map_alloc_check = fd_array_map_alloc_check, .map_alloc = array_of_map_alloc, .map_free = array_of_map_free, - .map_get_next_key = array_map_get_next_key, + .map_get_next_key = bpf_array_get_next_key, .map_lookup_elem = array_of_map_lookup_elem, .map_delete_elem = fd_array_map_delete_elem, .map_fd_get_ptr = bpf_map_fd_get_ptr, diff --git a/kernel/bpf/bpf_insn_array.c b/kernel/bpf/bpf_insn_array.c new file mode 100644 index 000000000000..c96630cb75bf --- /dev/null +++ b/kernel/bpf/bpf_insn_array.c @@ -0,0 +1,304 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* Copyright (c) 2025 Isovalent */ + +#include <linux/bpf.h> + +struct bpf_insn_array { + struct bpf_map map; + atomic_t used; + long *ips; + DECLARE_FLEX_ARRAY(struct bpf_insn_array_value, values); +}; + +#define cast_insn_array(MAP_PTR) \ + container_of((MAP_PTR), struct bpf_insn_array, map) + +#define INSN_DELETED ((u32)-1) + +static inline u64 insn_array_alloc_size(u32 max_entries) +{ + const u64 base_size = sizeof(struct bpf_insn_array); + const u64 entry_size = sizeof(struct bpf_insn_array_value); + + return base_size + max_entries * (entry_size + sizeof(long)); +} + +static int insn_array_alloc_check(union bpf_attr *attr) +{ + u32 value_size = sizeof(struct bpf_insn_array_value); + + if (attr->max_entries == 0 || attr->key_size != 4 || + attr->value_size != value_size || attr->map_flags != 0) + return -EINVAL; + + return 0; +} + +static void insn_array_free(struct bpf_map *map) +{ + struct bpf_insn_array *insn_array = cast_insn_array(map); + + bpf_map_area_free(insn_array); +} + +static struct bpf_map *insn_array_alloc(union bpf_attr *attr) +{ + u64 size = insn_array_alloc_size(attr->max_entries); + struct bpf_insn_array *insn_array; + + insn_array = bpf_map_area_alloc(size, NUMA_NO_NODE); + if (!insn_array) + return ERR_PTR(-ENOMEM); + + /* ips are allocated right after the insn_array->values[] array */ + insn_array->ips = (void *)&insn_array->values[attr->max_entries]; + + bpf_map_init_from_attr(&insn_array->map, attr); + + /* BPF programs aren't allowed to write to the map */ + insn_array->map.map_flags |= BPF_F_RDONLY_PROG; + + return &insn_array->map; +} + +static void *insn_array_lookup_elem(struct bpf_map *map, void *key) +{ + struct bpf_insn_array *insn_array = cast_insn_array(map); + u32 index = *(u32 *)key; + + if (unlikely(index >= insn_array->map.max_entries)) + return NULL; + + return &insn_array->values[index]; +} + +static long insn_array_update_elem(struct bpf_map *map, void *key, void *value, u64 map_flags) +{ + struct bpf_insn_array *insn_array = cast_insn_array(map); + u32 index = *(u32 *)key; + struct bpf_insn_array_value val = {}; + + if (unlikely(index >= insn_array->map.max_entries)) + return -E2BIG; + + if (unlikely(map_flags & BPF_NOEXIST)) + return -EEXIST; + + copy_map_value(map, &val, value); + if (val.jitted_off || val.xlated_off) + return -EINVAL; + + insn_array->values[index].orig_off = val.orig_off; + + return 0; +} + +static long insn_array_delete_elem(struct bpf_map *map, void *key) +{ + return -EINVAL; +} + +static int insn_array_check_btf(const struct bpf_map *map, + const struct btf *btf, + const struct btf_type *key_type, + const struct btf_type *value_type) +{ + if (!btf_type_is_i32(key_type)) + return -EINVAL; + + if (!btf_type_is_i64(value_type)) + return -EINVAL; + + return 0; +} + +static u64 insn_array_mem_usage(const struct bpf_map *map) +{ + return insn_array_alloc_size(map->max_entries); +} + +static int insn_array_map_direct_value_addr(const struct bpf_map *map, u64 *imm, u32 off) +{ + struct bpf_insn_array *insn_array = cast_insn_array(map); + + if ((off % sizeof(long)) != 0 || + (off / sizeof(long)) >= map->max_entries) + return -EINVAL; + + /* from BPF's point of view, this map is a jump table */ + *imm = (unsigned long)insn_array->ips + off; + + return 0; +} + +BTF_ID_LIST_SINGLE(insn_array_btf_ids, struct, bpf_insn_array) + +const struct bpf_map_ops insn_array_map_ops = { + .map_alloc_check = insn_array_alloc_check, + .map_alloc = insn_array_alloc, + .map_free = insn_array_free, + .map_get_next_key = bpf_array_get_next_key, + .map_lookup_elem = insn_array_lookup_elem, + .map_update_elem = insn_array_update_elem, + .map_delete_elem = insn_array_delete_elem, + .map_check_btf = insn_array_check_btf, + .map_mem_usage = insn_array_mem_usage, + .map_direct_value_addr = insn_array_map_direct_value_addr, + .map_btf_id = &insn_array_btf_ids[0], +}; + +static inline bool is_frozen(struct bpf_map *map) +{ + guard(mutex)(&map->freeze_mutex); + + return map->frozen; +} + +static bool is_insn_array(const struct bpf_map *map) +{ + return map->map_type == BPF_MAP_TYPE_INSN_ARRAY; +} + +static inline bool valid_offsets(const struct bpf_insn_array *insn_array, + const struct bpf_prog *prog) +{ + u32 off; + int i; + + for (i = 0; i < insn_array->map.max_entries; i++) { + off = insn_array->values[i].orig_off; + + if (off >= prog->len) + return false; + + if (off > 0) { + if (prog->insnsi[off-1].code == (BPF_LD | BPF_DW | BPF_IMM)) + return false; + } + } + + return true; +} + +int bpf_insn_array_init(struct bpf_map *map, const struct bpf_prog *prog) +{ + struct bpf_insn_array *insn_array = cast_insn_array(map); + struct bpf_insn_array_value *values = insn_array->values; + int i; + + if (!is_frozen(map)) + return -EINVAL; + + if (!valid_offsets(insn_array, prog)) + return -EINVAL; + + /* + * There can be only one program using the map + */ + if (atomic_xchg(&insn_array->used, 1)) + return -EBUSY; + + /* + * Reset all the map indexes to the original values. This is needed, + * e.g., when a replay of verification with different log level should + * be performed. + */ + for (i = 0; i < map->max_entries; i++) + values[i].xlated_off = values[i].orig_off; + + return 0; +} + +int bpf_insn_array_ready(struct bpf_map *map) +{ + struct bpf_insn_array *insn_array = cast_insn_array(map); + int i; + + for (i = 0; i < map->max_entries; i++) { + if (insn_array->values[i].xlated_off == INSN_DELETED) + continue; + if (!insn_array->ips[i]) + return -EFAULT; + } + + return 0; +} + +void bpf_insn_array_release(struct bpf_map *map) +{ + struct bpf_insn_array *insn_array = cast_insn_array(map); + + atomic_set(&insn_array->used, 0); +} + +void bpf_insn_array_adjust(struct bpf_map *map, u32 off, u32 len) +{ + struct bpf_insn_array *insn_array = cast_insn_array(map); + int i; + + if (len <= 1) + return; + + for (i = 0; i < map->max_entries; i++) { + if (insn_array->values[i].xlated_off <= off) + continue; + if (insn_array->values[i].xlated_off == INSN_DELETED) + continue; + insn_array->values[i].xlated_off += len - 1; + } +} + +void bpf_insn_array_adjust_after_remove(struct bpf_map *map, u32 off, u32 len) +{ + struct bpf_insn_array *insn_array = cast_insn_array(map); + int i; + + for (i = 0; i < map->max_entries; i++) { + if (insn_array->values[i].xlated_off < off) + continue; + if (insn_array->values[i].xlated_off == INSN_DELETED) + continue; + if (insn_array->values[i].xlated_off < off + len) + insn_array->values[i].xlated_off = INSN_DELETED; + else + insn_array->values[i].xlated_off -= len; + } +} + +/* + * This function is called by JITs. The image is the real program + * image, the offsets array set up the xlated -> jitted mapping. + * The offsets[xlated] offset should point to the beginning of + * the jitted instruction. + */ +void bpf_prog_update_insn_ptrs(struct bpf_prog *prog, u32 *offsets, void *image) +{ + struct bpf_insn_array *insn_array; + struct bpf_map *map; + u32 xlated_off; + int i, j; + + if (!offsets || !image) + return; + + for (i = 0; i < prog->aux->used_map_cnt; i++) { + map = prog->aux->used_maps[i]; + if (!is_insn_array(map)) + continue; + + insn_array = cast_insn_array(map); + for (j = 0; j < map->max_entries; j++) { + xlated_off = insn_array->values[j].xlated_off; + if (xlated_off == INSN_DELETED) + continue; + if (xlated_off < prog->aux->subprog_start) + continue; + xlated_off -= prog->aux->subprog_start; + if (xlated_off >= prog->len) + continue; + + insn_array->values[j].jitted_off = offsets[xlated_off]; + insn_array->ips[j] = (long)(image + offsets[xlated_off]); + } + } +} diff --git a/kernel/bpf/bpf_local_storage.c b/kernel/bpf/bpf_local_storage.c index b931fbceb54d..e2fe6c32822b 100644 --- a/kernel/bpf/bpf_local_storage.c +++ b/kernel/bpf/bpf_local_storage.c @@ -73,30 +73,24 @@ static bool selem_linked_to_map(const struct bpf_local_storage_elem *selem) struct bpf_local_storage_elem * bpf_selem_alloc(struct bpf_local_storage_map *smap, void *owner, - void *value, bool charge_mem, bool swap_uptrs, gfp_t gfp_flags) + void *value, bool swap_uptrs, gfp_t gfp_flags) { struct bpf_local_storage_elem *selem; - if (charge_mem && mem_charge(smap, owner, smap->elem_size)) + if (mem_charge(smap, owner, smap->elem_size)) return NULL; - if (smap->bpf_ma) { - selem = bpf_mem_cache_alloc_flags(&smap->selem_ma, gfp_flags); - if (selem) - /* Keep the original bpf_map_kzalloc behavior - * before started using the bpf_mem_cache_alloc. - * - * No need to use zero_map_value. The bpf_selem_free() - * only does bpf_mem_cache_free when there is - * no other bpf prog is using the selem. - */ - memset(SDATA(selem)->data, 0, smap->map.value_size); + if (smap->use_kmalloc_nolock) { + selem = bpf_map_kmalloc_nolock(&smap->map, smap->elem_size, + __GFP_ZERO, NUMA_NO_NODE); } else { selem = bpf_map_kzalloc(&smap->map, smap->elem_size, gfp_flags | __GFP_NOWARN); } if (selem) { + RCU_INIT_POINTER(SDATA(selem)->smap, smap); + if (value) { /* No need to call check_and_init_map_value as memory is zero init */ copy_map_value(&smap->map, SDATA(selem)->data, value); @@ -106,13 +100,12 @@ bpf_selem_alloc(struct bpf_local_storage_map *smap, void *owner, return selem; } - if (charge_mem) - mem_uncharge(smap, owner, smap->elem_size); + mem_uncharge(smap, owner, smap->elem_size); return NULL; } -/* rcu tasks trace callback for bpf_ma == false */ +/* rcu tasks trace callback for use_kmalloc_nolock == false */ static void __bpf_local_storage_free_trace_rcu(struct rcu_head *rcu) { struct bpf_local_storage *local_storage; @@ -127,12 +120,23 @@ static void __bpf_local_storage_free_trace_rcu(struct rcu_head *rcu) kfree_rcu(local_storage, rcu); } +/* Handle use_kmalloc_nolock == false */ +static void __bpf_local_storage_free(struct bpf_local_storage *local_storage, + bool vanilla_rcu) +{ + if (vanilla_rcu) + kfree_rcu(local_storage, rcu); + else + call_rcu_tasks_trace(&local_storage->rcu, + __bpf_local_storage_free_trace_rcu); +} + static void bpf_local_storage_free_rcu(struct rcu_head *rcu) { struct bpf_local_storage *local_storage; local_storage = container_of(rcu, struct bpf_local_storage, rcu); - bpf_mem_cache_raw_free(local_storage); + kfree_nolock(local_storage); } static void bpf_local_storage_free_trace_rcu(struct rcu_head *rcu) @@ -143,46 +147,27 @@ static void bpf_local_storage_free_trace_rcu(struct rcu_head *rcu) call_rcu(rcu, bpf_local_storage_free_rcu); } -/* Handle bpf_ma == false */ -static void __bpf_local_storage_free(struct bpf_local_storage *local_storage, - bool vanilla_rcu) -{ - if (vanilla_rcu) - kfree_rcu(local_storage, rcu); - else - call_rcu_tasks_trace(&local_storage->rcu, - __bpf_local_storage_free_trace_rcu); -} - static void bpf_local_storage_free(struct bpf_local_storage *local_storage, - struct bpf_local_storage_map *smap, - bool bpf_ma, bool reuse_now) + bool reuse_now) { if (!local_storage) return; - if (!bpf_ma) { + if (!local_storage->use_kmalloc_nolock) { __bpf_local_storage_free(local_storage, reuse_now); return; } - if (!reuse_now) { - call_rcu_tasks_trace(&local_storage->rcu, - bpf_local_storage_free_trace_rcu); + if (reuse_now) { + call_rcu(&local_storage->rcu, bpf_local_storage_free_rcu); return; } - if (smap) - bpf_mem_cache_free(&smap->storage_ma, local_storage); - else - /* smap could be NULL if the selem that triggered - * this 'local_storage' creation had been long gone. - * In this case, directly do call_rcu(). - */ - call_rcu(&local_storage->rcu, bpf_local_storage_free_rcu); + call_rcu_tasks_trace(&local_storage->rcu, + bpf_local_storage_free_trace_rcu); } -/* rcu tasks trace callback for bpf_ma == false */ +/* rcu tasks trace callback for use_kmalloc_nolock == false */ static void __bpf_selem_free_trace_rcu(struct rcu_head *rcu) { struct bpf_local_storage_elem *selem; @@ -194,7 +179,7 @@ static void __bpf_selem_free_trace_rcu(struct rcu_head *rcu) kfree_rcu(selem, rcu); } -/* Handle bpf_ma == false */ +/* Handle use_kmalloc_nolock == false */ static void __bpf_selem_free(struct bpf_local_storage_elem *selem, bool vanilla_rcu) { @@ -216,7 +201,7 @@ static void bpf_selem_free_rcu(struct rcu_head *rcu) migrate_disable(); bpf_obj_free_fields(smap->map.record, SDATA(selem)->data); migrate_enable(); - bpf_mem_cache_raw_free(selem); + kfree_nolock(selem); } static void bpf_selem_free_trace_rcu(struct rcu_head *rcu) @@ -228,14 +213,17 @@ static void bpf_selem_free_trace_rcu(struct rcu_head *rcu) } void bpf_selem_free(struct bpf_local_storage_elem *selem, - struct bpf_local_storage_map *smap, bool reuse_now) { - if (!smap->bpf_ma) { - /* Only task storage has uptrs and task storage - * has moved to bpf_mem_alloc. Meaning smap->bpf_ma == true - * for task storage, so this bpf_obj_free_fields() won't unpin - * any uptr. + struct bpf_local_storage_map *smap; + + smap = rcu_dereference_check(SDATA(selem)->smap, bpf_rcu_lock_held()); + + if (!smap->use_kmalloc_nolock) { + /* + * No uptr will be unpin even when reuse_now == false since uptr + * is only supported in task local storage, where + * smap->use_kmalloc_nolock == true. */ bpf_obj_free_fields(smap->map.record, SDATA(selem)->data); __bpf_selem_free(selem, reuse_now); @@ -243,18 +231,11 @@ void bpf_selem_free(struct bpf_local_storage_elem *selem, } if (reuse_now) { - /* reuse_now == true only happens when the storage owner - * (e.g. task_struct) is being destructed or the map itself - * is being destructed (ie map_free). In both cases, - * no bpf prog can have a hold on the selem. It is - * safe to unpin the uptrs and free the selem now. - */ - bpf_obj_free_fields(smap->map.record, SDATA(selem)->data); - /* Instead of using the vanilla call_rcu(), - * bpf_mem_cache_free will be able to reuse selem - * immediately. + /* + * While it is okay to call bpf_obj_free_fields() that unpins uptr when + * reuse_now == true, keep it in bpf_selem_free_rcu() for simplicity. */ - bpf_mem_cache_free(&smap->selem_ma, selem); + call_rcu(&selem->rcu, bpf_selem_free_rcu); return; } @@ -264,7 +245,6 @@ void bpf_selem_free(struct bpf_local_storage_elem *selem, static void bpf_selem_free_list(struct hlist_head *list, bool reuse_now) { struct bpf_local_storage_elem *selem; - struct bpf_local_storage_map *smap; struct hlist_node *n; /* The "_safe" iteration is needed. @@ -272,10 +252,8 @@ static void bpf_selem_free_list(struct hlist_head *list, bool reuse_now) * but bpf_selem_free will use the selem->rcu_head * which is union-ized with the selem->free_node. */ - hlist_for_each_entry_safe(selem, n, list, free_node) { - smap = rcu_dereference_check(SDATA(selem)->smap, bpf_rcu_lock_held()); - bpf_selem_free(selem, smap, reuse_now); - } + hlist_for_each_entry_safe(selem, n, list, free_node) + bpf_selem_free(selem, reuse_now); } /* local_storage->lock must be held and selem->local_storage == local_storage. @@ -284,7 +262,7 @@ static void bpf_selem_free_list(struct hlist_head *list, bool reuse_now) */ static bool bpf_selem_unlink_storage_nolock(struct bpf_local_storage *local_storage, struct bpf_local_storage_elem *selem, - bool uncharge_mem, struct hlist_head *free_selem_list) + struct hlist_head *free_selem_list) { struct bpf_local_storage_map *smap; bool free_local_storage; @@ -297,8 +275,7 @@ static bool bpf_selem_unlink_storage_nolock(struct bpf_local_storage *local_stor * The owner may be freed once the last selem is unlinked * from local_storage. */ - if (uncharge_mem) - mem_uncharge(smap, owner, smap->elem_size); + mem_uncharge(smap, owner, smap->elem_size); free_local_storage = hlist_is_singular_node(&selem->snode, &local_storage->list); @@ -336,47 +313,11 @@ static bool bpf_selem_unlink_storage_nolock(struct bpf_local_storage *local_stor return free_local_storage; } -static bool check_storage_bpf_ma(struct bpf_local_storage *local_storage, - struct bpf_local_storage_map *storage_smap, - struct bpf_local_storage_elem *selem) -{ - - struct bpf_local_storage_map *selem_smap; - - /* local_storage->smap may be NULL. If it is, get the bpf_ma - * from any selem in the local_storage->list. The bpf_ma of all - * local_storage and selem should have the same value - * for the same map type. - * - * If the local_storage->list is already empty, the caller will not - * care about the bpf_ma value also because the caller is not - * responsible to free the local_storage. - */ - - if (storage_smap) - return storage_smap->bpf_ma; - - if (!selem) { - struct hlist_node *n; - - n = rcu_dereference_check(hlist_first_rcu(&local_storage->list), - bpf_rcu_lock_held()); - if (!n) - return false; - - selem = hlist_entry(n, struct bpf_local_storage_elem, snode); - } - selem_smap = rcu_dereference_check(SDATA(selem)->smap, bpf_rcu_lock_held()); - - return selem_smap->bpf_ma; -} - static void bpf_selem_unlink_storage(struct bpf_local_storage_elem *selem, bool reuse_now) { - struct bpf_local_storage_map *storage_smap; struct bpf_local_storage *local_storage; - bool bpf_ma, free_local_storage = false; + bool free_local_storage = false; HLIST_HEAD(selem_free_list); unsigned long flags; @@ -386,20 +327,17 @@ static void bpf_selem_unlink_storage(struct bpf_local_storage_elem *selem, local_storage = rcu_dereference_check(selem->local_storage, bpf_rcu_lock_held()); - storage_smap = rcu_dereference_check(local_storage->smap, - bpf_rcu_lock_held()); - bpf_ma = check_storage_bpf_ma(local_storage, storage_smap, selem); raw_spin_lock_irqsave(&local_storage->lock, flags); if (likely(selem_linked_to_storage(selem))) free_local_storage = bpf_selem_unlink_storage_nolock( - local_storage, selem, true, &selem_free_list); + local_storage, selem, &selem_free_list); raw_spin_unlock_irqrestore(&local_storage->lock, flags); bpf_selem_free_list(&selem_free_list, reuse_now); if (free_local_storage) - bpf_local_storage_free(local_storage, storage_smap, bpf_ma, reuse_now); + bpf_local_storage_free(local_storage, reuse_now); } void bpf_selem_link_storage_nolock(struct bpf_local_storage *local_storage, @@ -434,7 +372,6 @@ void bpf_selem_link_map(struct bpf_local_storage_map *smap, unsigned long flags; raw_spin_lock_irqsave(&b->lock, flags); - RCU_INIT_POINTER(SDATA(selem)->smap, smap); hlist_add_head_rcu(&selem->map_node, &b->list); raw_spin_unlock_irqrestore(&b->lock, flags); } @@ -493,8 +430,9 @@ int bpf_local_storage_alloc(void *owner, if (err) return err; - if (smap->bpf_ma) - storage = bpf_mem_cache_alloc_flags(&smap->storage_ma, gfp_flags); + if (smap->use_kmalloc_nolock) + storage = bpf_map_kmalloc_nolock(&smap->map, sizeof(*storage), + __GFP_ZERO, NUMA_NO_NODE); else storage = bpf_map_kzalloc(&smap->map, sizeof(*storage), gfp_flags | __GFP_NOWARN); @@ -507,6 +445,7 @@ int bpf_local_storage_alloc(void *owner, INIT_HLIST_HEAD(&storage->list); raw_spin_lock_init(&storage->lock); storage->owner = owner; + storage->use_kmalloc_nolock = smap->use_kmalloc_nolock; bpf_selem_link_storage_nolock(storage, first_selem); bpf_selem_link_map(smap, first_selem); @@ -528,22 +467,12 @@ int bpf_local_storage_alloc(void *owner, bpf_selem_unlink_map(first_selem); err = -EAGAIN; goto uncharge; - - /* Note that even first_selem was linked to smap's - * bucket->list, first_selem can be freed immediately - * (instead of kfree_rcu) because - * bpf_local_storage_map_free() does a - * synchronize_rcu_mult (waiting for both sleepable and - * normal programs) before walking the bucket->list. - * Hence, no one is accessing selem from the - * bucket->list under rcu_read_lock(). - */ } return 0; uncharge: - bpf_local_storage_free(storage, smap, smap->bpf_ma, true); + bpf_local_storage_free(storage, true); mem_uncharge(smap, owner, sizeof(*storage)); return err; } @@ -582,13 +511,13 @@ bpf_local_storage_update(void *owner, struct bpf_local_storage_map *smap, if (err) return ERR_PTR(err); - selem = bpf_selem_alloc(smap, owner, value, true, swap_uptrs, gfp_flags); + selem = bpf_selem_alloc(smap, owner, value, swap_uptrs, gfp_flags); if (!selem) return ERR_PTR(-ENOMEM); err = bpf_local_storage_alloc(owner, smap, selem, gfp_flags); if (err) { - bpf_selem_free(selem, smap, true); + bpf_selem_free(selem, true); mem_uncharge(smap, owner, smap->elem_size); return ERR_PTR(err); } @@ -616,7 +545,7 @@ bpf_local_storage_update(void *owner, struct bpf_local_storage_map *smap, /* A lookup has just been done before and concluded a new selem is * needed. The chance of an unnecessary alloc is unlikely. */ - alloc_selem = selem = bpf_selem_alloc(smap, owner, value, true, swap_uptrs, gfp_flags); + alloc_selem = selem = bpf_selem_alloc(smap, owner, value, swap_uptrs, gfp_flags); if (!alloc_selem) return ERR_PTR(-ENOMEM); @@ -656,7 +585,7 @@ bpf_local_storage_update(void *owner, struct bpf_local_storage_map *smap, if (old_sdata) { bpf_selem_unlink_map(SELEM(old_sdata)); bpf_selem_unlink_storage_nolock(local_storage, SELEM(old_sdata), - true, &old_selem_free_list); + &old_selem_free_list); } unlock: @@ -664,7 +593,7 @@ unlock: bpf_selem_free_list(&old_selem_free_list, false); if (alloc_selem) { mem_uncharge(smap, owner, smap->elem_size); - bpf_selem_free(alloc_selem, smap, true); + bpf_selem_free(alloc_selem, true); } return err ? ERR_PTR(err) : SDATA(selem); } @@ -730,16 +659,12 @@ int bpf_local_storage_map_check_btf(const struct bpf_map *map, void bpf_local_storage_destroy(struct bpf_local_storage *local_storage) { - struct bpf_local_storage_map *storage_smap; struct bpf_local_storage_elem *selem; - bool bpf_ma, free_storage = false; + bool free_storage = false; HLIST_HEAD(free_selem_list); struct hlist_node *n; unsigned long flags; - storage_smap = rcu_dereference_check(local_storage->smap, bpf_rcu_lock_held()); - bpf_ma = check_storage_bpf_ma(local_storage, storage_smap, NULL); - /* Neither the bpf_prog nor the bpf_map's syscall * could be modifying the local_storage->list now. * Thus, no elem can be added to or deleted from the @@ -762,14 +687,14 @@ void bpf_local_storage_destroy(struct bpf_local_storage *local_storage) * of the loop will set the free_cgroup_storage to true. */ free_storage = bpf_selem_unlink_storage_nolock( - local_storage, selem, true, &free_selem_list); + local_storage, selem, &free_selem_list); } raw_spin_unlock_irqrestore(&local_storage->lock, flags); bpf_selem_free_list(&free_selem_list, true); if (free_storage) - bpf_local_storage_free(local_storage, storage_smap, bpf_ma, true); + bpf_local_storage_free(local_storage, true); } u64 bpf_local_storage_map_mem_usage(const struct bpf_map *map) @@ -782,20 +707,10 @@ u64 bpf_local_storage_map_mem_usage(const struct bpf_map *map) return usage; } -/* When bpf_ma == true, the bpf_mem_alloc is used to allocate and free memory. - * A deadlock free allocator is useful for storage that the bpf prog can easily - * get a hold of the owner PTR_TO_BTF_ID in any context. eg. bpf_get_current_task_btf. - * The task and cgroup storage fall into this case. The bpf_mem_alloc reuses - * memory immediately. To be reuse-immediate safe, the owner destruction - * code path needs to go through a rcu grace period before calling - * bpf_local_storage_destroy(). - * - * When bpf_ma == false, the kmalloc and kfree are used. - */ struct bpf_map * bpf_local_storage_map_alloc(union bpf_attr *attr, struct bpf_local_storage_cache *cache, - bool bpf_ma) + bool use_kmalloc_nolock) { struct bpf_local_storage_map *smap; unsigned int i; @@ -829,20 +744,9 @@ bpf_local_storage_map_alloc(union bpf_attr *attr, /* In PREEMPT_RT, kmalloc(GFP_ATOMIC) is still not safe in non * preemptible context. Thus, enforce all storages to use - * bpf_mem_alloc when CONFIG_PREEMPT_RT is enabled. + * kmalloc_nolock() when CONFIG_PREEMPT_RT is enabled. */ - smap->bpf_ma = IS_ENABLED(CONFIG_PREEMPT_RT) ? true : bpf_ma; - if (smap->bpf_ma) { - err = bpf_mem_alloc_init(&smap->selem_ma, smap->elem_size, false); - if (err) - goto free_smap; - - err = bpf_mem_alloc_init(&smap->storage_ma, sizeof(struct bpf_local_storage), false); - if (err) { - bpf_mem_alloc_destroy(&smap->selem_ma); - goto free_smap; - } - } + smap->use_kmalloc_nolock = IS_ENABLED(CONFIG_PREEMPT_RT) ? true : use_kmalloc_nolock; smap->cache_idx = bpf_local_storage_cache_idx_get(cache); return &smap->map; @@ -912,12 +816,9 @@ voi |
