diff options
Diffstat (limited to 'kernel')
45 files changed, 4920 insertions, 703 deletions
diff --git a/kernel/Makefile b/kernel/Makefile index b74820d8b264..e5bc66a94b70 100644 --- a/kernel/Makefile +++ b/kernel/Makefile @@ -12,7 +12,7 @@ obj-y = fork.o exec_domain.o panic.o \ notifier.o ksysfs.o cred.o reboot.o \ async.o range.o smpboot.o ucount.o regset.o -obj-$(CONFIG_BPFILTER) += usermode_driver.o +obj-$(CONFIG_USERMODE_DRIVER) += usermode_driver.o obj-$(CONFIG_MODULES) += kmod.o obj-$(CONFIG_MULTIUSER) += groups.o diff --git a/kernel/bpf/Makefile b/kernel/bpf/Makefile index e6eb9c0402da..bdc8cd1b6767 100644 --- a/kernel/bpf/Makefile +++ b/kernel/bpf/Makefile @@ -5,6 +5,7 @@ CFLAGS_core.o += $(call cc-disable-warning, override-init) obj-$(CONFIG_BPF_SYSCALL) += syscall.o verifier.o inode.o helpers.o tnum.o bpf_iter.o map_iter.o task_iter.o prog_iter.o obj-$(CONFIG_BPF_SYSCALL) += hashtab.o arraymap.o percpu_freelist.o bpf_lru_list.o lpm_trie.o map_in_map.o obj-$(CONFIG_BPF_SYSCALL) += local_storage.o queue_stack_maps.o ringbuf.o +obj-${CONFIG_BPF_LSM} += bpf_inode_storage.o obj-$(CONFIG_BPF_SYSCALL) += disasm.o obj-$(CONFIG_BPF_JIT) += trampoline.o obj-$(CONFIG_BPF_SYSCALL) += btf.o @@ -12,6 +13,7 @@ obj-$(CONFIG_BPF_JIT) += dispatcher.o ifeq ($(CONFIG_NET),y) obj-$(CONFIG_BPF_SYSCALL) += devmap.o obj-$(CONFIG_BPF_SYSCALL) += cpumap.o +obj-$(CONFIG_BPF_SYSCALL) += bpf_local_storage.o obj-$(CONFIG_BPF_SYSCALL) += offload.o obj-$(CONFIG_BPF_SYSCALL) += net_namespace.o endif @@ -29,3 +31,4 @@ ifeq ($(CONFIG_BPF_JIT),y) obj-$(CONFIG_BPF_SYSCALL) += bpf_struct_ops.o obj-${CONFIG_BPF_LSM} += bpf_lsm.o endif +obj-$(CONFIG_BPF_PRELOAD) += preload/ diff --git a/kernel/bpf/arraymap.c b/kernel/bpf/arraymap.c index 8ff419b632a6..c6c81eceb68f 100644 --- a/kernel/bpf/arraymap.c +++ b/kernel/bpf/arraymap.c @@ -10,11 +10,13 @@ #include <linux/filter.h> #include <linux/perf_event.h> #include <uapi/linux/btf.h> +#include <linux/rcupdate_trace.h> #include "map_in_map.h" #define ARRAY_CREATE_FLAG_MASK \ - (BPF_F_NUMA_NODE | BPF_F_MMAPABLE | BPF_F_ACCESS_MASK) + (BPF_F_NUMA_NODE | BPF_F_MMAPABLE | BPF_F_ACCESS_MASK | \ + BPF_F_PRESERVE_ELEMS | BPF_F_INNER_MAP) static void bpf_array_free_percpu(struct bpf_array *array) { @@ -60,7 +62,11 @@ int array_map_alloc_check(union bpf_attr *attr) return -EINVAL; if (attr->map_type != BPF_MAP_TYPE_ARRAY && - attr->map_flags & BPF_F_MMAPABLE) + attr->map_flags & (BPF_F_MMAPABLE | BPF_F_INNER_MAP)) + return -EINVAL; + + if (attr->map_type != BPF_MAP_TYPE_PERF_EVENT_ARRAY && + attr->map_flags & BPF_F_PRESERVE_ELEMS) return -EINVAL; if (attr->value_size > KMALLOC_MAX_SIZE) @@ -208,7 +214,7 @@ static int array_map_direct_value_meta(const struct bpf_map *map, u64 imm, } /* emit BPF instructions equivalent to C code of array_map_lookup_elem() */ -static u32 array_map_gen_lookup(struct bpf_map *map, struct bpf_insn *insn_buf) +static int array_map_gen_lookup(struct bpf_map *map, struct bpf_insn *insn_buf) { struct bpf_array *array = container_of(map, struct bpf_array, map); struct bpf_insn *insn = insn_buf; @@ -217,6 +223,9 @@ static u32 array_map_gen_lookup(struct bpf_map *map, struct bpf_insn *insn_buf) const int map_ptr = BPF_REG_1; const int index = BPF_REG_2; + if (map->map_flags & BPF_F_INNER_MAP) + return -EOPNOTSUPP; + *insn++ = BPF_ALU64_IMM(BPF_ADD, map_ptr, offsetof(struct bpf_array, value)); *insn++ = BPF_LDX_MEM(BPF_W, ret, index, 0); if (!map->bypass_spec_v1) { @@ -487,6 +496,15 @@ static int array_map_mmap(struct bpf_map *map, struct vm_area_struct *vma) vma->vm_pgoff + pgoff); } +static bool array_map_meta_equal(const struct bpf_map *meta0, + const struct bpf_map *meta1) +{ + if (!bpf_map_meta_equal(meta0, meta1)) + return false; + return meta0->map_flags & BPF_F_INNER_MAP ? true : + meta0->max_entries == meta1->max_entries; +} + struct bpf_iter_seq_array_map_info { struct bpf_map *map; void *percpu_value_buf; @@ -625,6 +643,7 @@ static const struct bpf_iter_seq_info iter_seq_info = { static int array_map_btf_id; const struct bpf_map_ops array_map_ops = { + .map_meta_equal = array_map_meta_equal, .map_alloc_check = array_map_alloc_check, .map_alloc = array_map_alloc, .map_free = array_map_free, @@ -647,6 +666,7 @@ const struct bpf_map_ops array_map_ops = { static int percpu_array_map_btf_id; const struct bpf_map_ops percpu_array_map_ops = { + .map_meta_equal = bpf_map_meta_equal, .map_alloc_check = array_map_alloc_check, .map_alloc = array_map_alloc, .map_free = array_map_free, @@ -888,6 +908,7 @@ static void prog_array_map_poke_run(struct bpf_map *map, u32 key, struct bpf_prog *old, struct bpf_prog *new) { + u8 *old_addr, *new_addr, *old_bypass_addr; struct prog_poke_elem *elem; struct bpf_array_aux *aux; @@ -908,12 +929,13 @@ static void prog_array_map_poke_run(struct bpf_map *map, u32 key, * there could be danger of use after free otherwise. * 2) Initially when we start tracking aux, the program * is not JITed yet and also does not have a kallsyms - * entry. We skip these as poke->ip_stable is not - * active yet. The JIT will do the final fixup before - * setting it stable. The various poke->ip_stable are - * successively activated, so tail call updates can - * arrive from here while JIT is still finishing its - * final fixup for non-activated poke entries. + * entry. We skip these as poke->tailcall_target_stable + * is not active yet. The JIT will do the final fixup + * before setting it stable. The various + * poke->tailcall_target_stable are successively + * activated, so tail call updates can arrive from here + * while JIT is still finishing its final fixup for + * non-activated poke entries. * 3) On program teardown, the program's kallsym entry gets * removed out of RCU callback, but we can only untrack * from sleepable context, therefore bpf_arch_text_poke() @@ -930,7 +952,7 @@ static void prog_array_map_poke_run(struct bpf_map *map, u32 key, * 5) Any other error happening below from bpf_arch_text_poke() * is a unexpected bug. */ - if (!READ_ONCE(poke->ip_stable)) + if (!READ_ONCE(poke->tailcall_target_stable)) continue; if (poke->reason != BPF_POKE_REASON_TAIL_CALL) continue; @@ -938,12 +960,39 @@ static void prog_array_map_poke_run(struct bpf_map *map, u32 key, poke->tail_call.key != key) continue; - ret = bpf_arch_text_poke(poke->ip, BPF_MOD_JUMP, - old ? (u8 *)old->bpf_func + - poke->adj_off : NULL, - new ? (u8 *)new->bpf_func + - poke->adj_off : NULL); - BUG_ON(ret < 0 && ret != -EINVAL); + old_bypass_addr = old ? NULL : poke->bypass_addr; + old_addr = old ? (u8 *)old->bpf_func + poke->adj_off : NULL; + new_addr = new ? (u8 *)new->bpf_func + poke->adj_off : NULL; + + if (new) { + ret = bpf_arch_text_poke(poke->tailcall_target, + BPF_MOD_JUMP, + old_addr, new_addr); + BUG_ON(ret < 0 && ret != -EINVAL); + if (!old) { + ret = bpf_arch_text_poke(poke->tailcall_bypass, + BPF_MOD_JUMP, + poke->bypass_addr, + NULL); + BUG_ON(ret < 0 && ret != -EINVAL); + } + } else { + ret = bpf_arch_text_poke(poke->tailcall_bypass, + BPF_MOD_JUMP, + old_bypass_addr, + poke->bypass_addr); + BUG_ON(ret < 0 && ret != -EINVAL); + /* let other CPUs finish the execution of program + * so that it will not possible to expose them + * to invalid nop, stack unwind, nop state + */ + if (!ret) + synchronize_rcu(); + ret = bpf_arch_text_poke(poke->tailcall_target, + BPF_MOD_JUMP, + old_addr, NULL); + BUG_ON(ret < 0 && ret != -EINVAL); + } } } } @@ -1003,6 +1052,11 @@ static void prog_array_map_free(struct bpf_map *map) fd_array_map_free(map); } +/* prog_array->aux->{type,jited} is a runtime binding. + * Doing static check alone in the verifier is not enough. + * Thus, prog_array_map cannot be used as an inner_map + * and map_meta_equal is not implemented. + */ static int prog_array_map_btf_id; const struct bpf_map_ops prog_array_map_ops = { .map_alloc_check = fd_array_map_alloc_check, @@ -1090,6 +1144,9 @@ static void perf_event_fd_array_release(struct bpf_map *map, struct bpf_event_entry *ee; int i; + if (map->map_flags & BPF_F_PRESERVE_ELEMS) + return; + rcu_read_lock(); for (i = 0; i < array->map.max_entries; i++) { ee = READ_ONCE(array->ptrs[i]); @@ -1099,11 +1156,19 @@ static void perf_event_fd_array_release(struct bpf_map *map, rcu_read_unlock(); } +static void perf_event_fd_array_map_free(struct bpf_map *map) +{ + if (map->map_flags & BPF_F_PRESERVE_ELEMS) + bpf_fd_array_map_clear(map); + fd_array_map_free(map); +} + static int perf_event_array_map_btf_id; const struct bpf_map_ops perf_event_array_map_ops = { + .map_meta_equal = bpf_map_meta_equal, .map_alloc_check = fd_array_map_alloc_check, .map_alloc = array_map_alloc, - .map_free = fd_array_map_free, + .map_free = perf_event_fd_array_map_free, .map_get_next_key = array_map_get_next_key, .map_lookup_elem = fd_array_map_lookup_elem, .map_delete_elem = fd_array_map_delete_elem, @@ -1137,6 +1202,7 @@ static void cgroup_fd_array_free(struct bpf_map *map) static int cgroup_array_map_btf_id; const struct bpf_map_ops cgroup_array_map_ops = { + .map_meta_equal = bpf_map_meta_equal, .map_alloc_check = fd_array_map_alloc_check, .map_alloc = array_map_alloc, .map_free = cgroup_fd_array_free, @@ -1190,7 +1256,7 @@ static void *array_of_map_lookup_elem(struct bpf_map *map, void *key) return READ_ONCE(*inner_map); } -static u32 array_of_map_gen_lookup(struct bpf_map *map, +static int array_of_map_gen_lookup(struct bpf_map *map, struct bpf_insn *insn_buf) { struct bpf_array *array = container_of(map, struct bpf_array, map); diff --git a/kernel/bpf/bpf_inode_storage.c b/kernel/bpf/bpf_inode_storage.c new file mode 100644 index 000000000000..6edff97ad594 --- /dev/null +++ b/kernel/bpf/bpf_inode_storage.c @@ -0,0 +1,272 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Copyright (c) 2019 Facebook + * Copyright 2020 Google LLC. + */ + +#include <linux/rculist.h> +#include <linux/list.h> +#include <linux/hash.h> +#include <linux/types.h> +#include <linux/spinlock.h> +#include <linux/bpf.h> +#include <linux/bpf_local_storage.h> +#include <net/sock.h> +#include <uapi/linux/sock_diag.h> +#include <uapi/linux/btf.h> +#include <linux/bpf_lsm.h> +#include <linux/btf_ids.h> +#include <linux/fdtable.h> + +DEFINE_BPF_STORAGE_CACHE(inode_cache); + +static struct bpf_local_storage __rcu ** +inode_storage_ptr(void *owner) +{ + struct inode *inode = owner; + struct bpf_storage_blob *bsb; + + bsb = bpf_inode(inode); + if (!bsb) + return NULL; + return &bsb->storage; +} + +static struct bpf_local_storage_data *inode_storage_lookup(struct inode *inode, + struct bpf_map *map, + bool cacheit_lockit) +{ + struct bpf_local_storage *inode_storage; + struct bpf_local_storage_map *smap; + struct bpf_storage_blob *bsb; + + bsb = bpf_inode(inode); + if (!bsb) + return NULL; + + inode_storage = rcu_dereference(bsb->storage); + if (!inode_storage) + return NULL; + + smap = (struct bpf_local_storage_map *)map; + return bpf_local_storage_lookup(inode_storage, smap, cacheit_lockit); +} + +void bpf_inode_storage_free(struct inode *inode) +{ + struct bpf_local_storage_elem *selem; + struct bpf_local_storage *local_storage; + bool free_inode_storage = false; + struct bpf_storage_blob *bsb; + struct hlist_node *n; + + bsb = bpf_inode(inode); + if (!bsb) + return; + + rcu_read_lock(); + + local_storage = rcu_dereference(bsb->storage); + if (!local_storage) { + rcu_read_unlock(); + return; + } + + /* Netiher 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 + * local_storage->list by the bpf_prog or by the bpf-map's syscall. + * + * It is racing with bpf_local_storage_map_free() alone + * when unlinking elem from the local_storage->list and + * the map's bucket->list. + */ + raw_spin_lock_bh(&local_storage->lock); + hlist_for_each_entry_safe(selem, n, &local_storage->list, snode) { + /* Always unlink from map before unlinking from + * local_storage. + */ + bpf_selem_unlink_map(selem); + free_inode_storage = bpf_selem_unlink_storage_nolock( + local_storage, selem, false); + } + raw_spin_unlock_bh(&local_storage->lock); + rcu_read_unlock(); + + /* free_inoode_storage should always be true as long as + * local_storage->list was non-empty. + */ + if (free_inode_storage) + kfree_rcu(local_storage, rcu); +} + +static void *bpf_fd_inode_storage_lookup_elem(struct bpf_map *map, void *key) +{ + struct bpf_local_storage_data *sdata; + struct file *f; + int fd; + + fd = *(int *)key; + f = fget_raw(fd); + if (!f) + return NULL; + + sdata = inode_storage_lookup(f->f_inode, map, true); + fput(f); + return sdata ? sdata->data : NULL; +} + +static int bpf_fd_inode_storage_update_elem(struct bpf_map *map, void *key, + void *value, u64 map_flags) +{ + struct bpf_local_storage_data *sdata; + struct file *f; + int fd; + + fd = *(int *)key; + f = fget_raw(fd); + if (!f || !inode_storage_ptr(f->f_inode)) + return -EBADF; + + sdata = bpf_local_storage_update(f->f_inode, + (struct bpf_local_storage_map *)map, + value, map_flags); + fput(f); + return PTR_ERR_OR_ZERO(sdata); +} + +static int inode_storage_delete(struct inode *inode, struct bpf_map *map) +{ + struct bpf_local_storage_data *sdata; + + sdata = inode_storage_lookup(inode, map, false); + if (!sdata) + return -ENOENT; + + bpf_selem_unlink(SELEM(sdata)); + + return 0; +} + +static int bpf_fd_inode_storage_delete_elem(struct bpf_map *map, void *key) +{ + struct file *f; + int fd, err; + + fd = *(int *)key; + f = fget_raw(fd); + if (!f) + return -EBADF; + + err = inode_storage_delete(f->f_inode, map); + fput(f); + return err; +} + +BPF_CALL_4(bpf_inode_storage_get, struct bpf_map *, map, struct inode *, inode, + void *, value, u64, flags) +{ + struct bpf_local_storage_data *sdata; + + if (flags & ~(BPF_LOCAL_STORAGE_GET_F_CREATE)) + return (unsigned long)NULL; + + /* explicitly check that the inode_storage_ptr is not + * NULL as inode_storage_lookup returns NULL in this case and + * bpf_local_storage_update expects the owner to have a + * valid storage pointer. + */ + if (!inode_storage_ptr(inode)) + return (unsigned long)NULL; + + sdata = inode_storage_lookup(inode, map, true); + if (sdata) + return (unsigned long)sdata->data; + + /* This helper must only called from where the inode is gurranteed + * to have a refcount and cannot be freed. + */ + if (flags & BPF_LOCAL_STORAGE_GET_F_CREATE) { + sdata = bpf_local_storage_update( + inode, (struct bpf_local_storage_map *)map, value, + BPF_NOEXIST); + return IS_ERR(sdata) ? (unsigned long)NULL : + (unsigned long)sdata->data; + } + + return (unsigned long)NULL; +} + +BPF_CALL_2(bpf_inode_storage_delete, + struct bpf_map *, map, struct inode *, inode) +{ + /* This helper must only called from where the inode is gurranteed + * to have a refcount and cannot be freed. + */ + return inode_storage_delete(inode, map); +} + +static int notsupp_get_next_key(struct bpf_map *map, void *key, + void *next_key) +{ + return -ENOTSUPP; +} + +static struct bpf_map *inode_storage_map_alloc(union bpf_attr *attr) +{ + struct bpf_local_storage_map *smap; + + smap = bpf_local_storage_map_alloc(attr); + if (IS_ERR(smap)) + return ERR_CAST(smap); + + smap->cache_idx = bpf_local_storage_cache_idx_get(&inode_cache); + return &smap->map; +} + +static void inode_storage_map_free(struct bpf_map *map) +{ + struct bpf_local_storage_map *smap; + + smap = (struct bpf_local_storage_map *)map; + bpf_local_storage_cache_idx_free(&inode_cache, smap->cache_idx); + bpf_local_storage_map_free(smap); +} + +static int inode_storage_map_btf_id; +const struct bpf_map_ops inode_storage_map_ops = { + .map_meta_equal = bpf_map_meta_equal, + .map_alloc_check = bpf_local_storage_map_alloc_check, + .map_alloc = inode_storage_map_alloc, + .map_free = inode_storage_map_free, + .map_get_next_key = notsupp_get_next_key, + .map_lookup_elem = bpf_fd_inode_storage_lookup_elem, + .map_update_elem = bpf_fd_inode_storage_update_elem, + .map_delete_elem = bpf_fd_inode_storage_delete_elem, + .map_check_btf = bpf_local_storage_map_check_btf, + .map_btf_name = "bpf_local_storage_map", + .map_btf_id = &inode_storage_map_btf_id, + .map_owner_storage_ptr = inode_storage_ptr, +}; + +BTF_ID_LIST_SINGLE(bpf_inode_storage_btf_ids, struct, inode) + +const struct bpf_func_proto bpf_inode_storage_get_proto = { + .func = bpf_inode_storage_get, + .gpl_only = false, + .ret_type = RET_PTR_TO_MAP_VALUE_OR_NULL, + .arg1_type = ARG_CONST_MAP_PTR, + .arg2_type = ARG_PTR_TO_BTF_ID, + .arg2_btf_id = &bpf_inode_storage_btf_ids[0], + .arg3_type = ARG_PTR_TO_MAP_VALUE_OR_NULL, + .arg4_type = ARG_ANYTHING, +}; + +const struct bpf_func_proto bpf_inode_storage_delete_proto = { + .func = bpf_inode_storage_delete, + .gpl_only = false, + .ret_type = RET_INTEGER, + .arg1_type = ARG_CONST_MAP_PTR, + .arg2_type = ARG_PTR_TO_BTF_ID, + .arg2_btf_id = &bpf_inode_storage_btf_ids[0], +}; diff --git a/kernel/bpf/bpf_iter.c b/kernel/bpf/bpf_iter.c index 8faa2ce89396..8f10e30ea0b0 100644 --- a/kernel/bpf/bpf_iter.c +++ b/kernel/bpf/bpf_iter.c @@ -88,8 +88,8 @@ static ssize_t bpf_seq_read(struct file *file, char __user *buf, size_t size, mutex_lock(&seq->lock); if (!seq->buf) { - seq->size = PAGE_SIZE; - seq->buf = kmalloc(seq->size, GFP_KERNEL); + seq->size = PAGE_SIZE << 3; + seq->buf = kvmalloc(seq->size, GFP_KERNEL); if (!seq->buf) { err = -ENOMEM; goto done; @@ -390,10 +390,68 @@ out_unlock: return ret; } +static void bpf_iter_link_show_fdinfo(const struct bpf_link *link, + struct seq_file *seq) +{ + struct bpf_iter_link *iter_link = + container_of(link, struct bpf_iter_link, link); + bpf_iter_show_fdinfo_t show_fdinfo; + + seq_printf(seq, + "target_name:\t%s\n", + iter_link->tinfo->reg_info->target); + + show_fdinfo = iter_link->tinfo->reg_info->show_fdinfo; + if (show_fdinfo) + show_fdinfo(&iter_link->aux, seq); +} + +static int bpf_iter_link_fill_link_info(const struct bpf_link *link, + struct bpf_link_info *info) +{ + struct bpf_iter_link *iter_link = + container_of(link, struct bpf_iter_link, link); + char __user *ubuf = u64_to_user_ptr(info->iter.target_name); + bpf_iter_fill_link_info_t fill_link_info; + u32 ulen = info->iter.target_name_len; + const char *target_name; + u32 target_len; + + if (!ulen ^ !ubuf) + return -EINVAL; + + target_name = iter_link->tinfo->reg_info->target; + target_len = strlen(target_name); + info->iter.target_name_len = target_len + 1; + + if (ubuf) { + if (ulen >= target_len + 1) { + if (copy_to_user(ubuf, target_name, target_len + 1)) + return -EFAULT; + } else { + char zero = '\0'; + + if (copy_to_user(ubuf, target_name, ulen - 1)) + return -EFAULT; + if (put_user(zero, ubuf + ulen - 1)) + return -EFAULT; + return -ENOSPC; + } + } + + fill_link_info = iter_link->tinfo->reg_info->fill_link_info; + if (fill_link_info) + return fill_link_info(&iter_link->aux, info); + + return 0; +} + static const struct bpf_link_ops bpf_iter_link_lops = { .release = bpf_iter_link_release, .dealloc = bpf_iter_link_dealloc, .update_prog = bpf_iter_link_replace, + .show_fdinfo = bpf_iter_link_show_fdinfo, + .fill_link_info = bpf_iter_link_fill_link_info, }; bool bpf_link_is_iter(struct bpf_link *link) diff --git a/kernel/bpf/bpf_local_storage.c b/kernel/bpf/bpf_local_storage.c new file mode 100644 index 000000000000..5d3a7af9ba9b --- /dev/null +++ b/kernel/bpf/bpf_local_storage.c @@ -0,0 +1,600 @@ +// SPDX-License-Identifier: GPL-2.0 +/* Copyright (c) 2019 Facebook */ +#include <linux/rculist.h> +#include <linux/list.h> +#include <linux/hash.h> +#include <linux/types.h> +#include <linux/spinlock.h> +#include <linux/bpf.h> +#include <linux/btf_ids.h> +#include <linux/bpf_local_storage.h> +#include <net/sock.h> +#include <uapi/linux/sock_diag.h> +#include <uapi/linux/btf.h> + +#define BPF_LOCAL_STORAGE_CREATE_FLAG_MASK (BPF_F_NO_PREALLOC | BPF_F_CLONE) + +static struct bpf_local_storage_map_bucket * +select_bucket(struct bpf_local_storage_map *smap, + struct bpf_local_storage_elem *selem) +{ + return &smap->buckets[hash_ptr(selem, smap->bucket_log)]; +} + +static int mem_charge(struct bpf_local_storage_map *smap, void *owner, u32 size) +{ + struct bpf_map *map = &smap->map; + + if (!map->ops->map_local_storage_charge) + return 0; + + return map->ops->map_local_storage_charge(smap, owner, size); +} + +static void mem_uncharge(struct bpf_local_storage_map *smap, void *owner, + u32 size) +{ + struct bpf_map *map = &smap->map; + + if (map->ops->map_local_storage_uncharge) + map->ops->map_local_storage_uncharge(smap, owner, size); +} + +static struct bpf_local_storage __rcu ** +owner_storage(struct bpf_local_storage_map *smap, void *owner) +{ + struct bpf_map *map = &smap->map; + + return map->ops->map_owner_storage_ptr(owner); +} + +static bool selem_linked_to_storage(const struct bpf_local_storage_elem *selem) +{ + return !hlist_unhashed(&selem->snode); +} + +static bool selem_linked_to_map(const struct bpf_local_storage_elem *selem) +{ + return !hlist_unhashed(&selem->map_node); +} + +struct bpf_local_storage_elem * +bpf_selem_alloc(struct bpf_local_storage_map *smap, void *owner, + void *value, bool charge_mem) +{ + struct bpf_local_storage_elem *selem; + + if (charge_mem && mem_charge(smap, owner, smap->elem_size)) + return NULL; + + selem = kzalloc(smap->elem_size, GFP_ATOMIC | __GFP_NOWARN); + if (selem) { + if (value) + memcpy(SDATA(selem)->data, value, smap->map.value_size); + return selem; + } + + if (charge_mem) + mem_uncharge(smap, owner, smap->elem_size); + + return NULL; +} + +/* local_storage->lock must be held and selem->local_storage == local_storage. + * The caller must ensure selem->smap is still valid to be + * dereferenced for its smap->elem_size and smap->cache_idx. + */ +bool bpf_selem_unlink_storage_nolock(struct bpf_local_storage *local_storage, + struct bpf_local_storage_elem *selem, + bool uncharge_mem) +{ + struct bpf_local_storage_map *smap; + bool free_local_storage; + void *owner; + + smap = rcu_dereference(SDATA(selem)->smap); + owner = local_storage->owner; + + /* All uncharging on the owner must be done first. + * The owner may be freed once the last selem is unlinked + * from local_storage. + */ + if (uncharge_mem) + mem_uncharge(smap, owner, smap->elem_size); + + free_local_storage = hlist_is_singular_node(&selem->snode, + &local_storage->list); + if (free_local_storage) { + mem_uncharge(smap, owner, sizeof(struct bpf_local_storage)); + local_storage->owner = NULL; + + /* After this RCU_INIT, owner may be freed and cannot be used */ + RCU_INIT_POINTER(*owner_storage(smap, owner), NULL); + + / |