diff options
Diffstat (limited to 'kernel/bpf')
| -rw-r--r-- | kernel/bpf/core.c | 29 | ||||
| -rw-r--r-- | kernel/bpf/syscall.c | 165 |
2 files changed, 180 insertions, 14 deletions
diff --git a/kernel/bpf/core.c b/kernel/bpf/core.c index 8b7002488251..f0c30c59b317 100644 --- a/kernel/bpf/core.c +++ b/kernel/bpf/core.c @@ -27,6 +27,7 @@ #include <linux/random.h> #include <linux/moduleloader.h> #include <asm/unaligned.h> +#include <linux/bpf.h> /* Registers */ #define BPF_R0 regs[BPF_REG_0] @@ -71,7 +72,7 @@ struct bpf_prog *bpf_prog_alloc(unsigned int size, gfp_t gfp_extra_flags) { gfp_t gfp_flags = GFP_KERNEL | __GFP_HIGHMEM | __GFP_ZERO | gfp_extra_flags; - struct bpf_work_struct *ws; + struct bpf_prog_aux *aux; struct bpf_prog *fp; size = round_up(size, PAGE_SIZE); @@ -79,14 +80,14 @@ struct bpf_prog *bpf_prog_alloc(unsigned int size, gfp_t gfp_extra_flags) if (fp == NULL) return NULL; - ws = kmalloc(sizeof(*ws), GFP_KERNEL | gfp_extra_flags); - if (ws == NULL) { + aux = kzalloc(sizeof(*aux), GFP_KERNEL | gfp_extra_flags); + if (aux == NULL) { vfree(fp); return NULL; } fp->pages = size / PAGE_SIZE; - fp->work = ws; + fp->aux = aux; return fp; } @@ -110,10 +111,10 @@ struct bpf_prog *bpf_prog_realloc(struct bpf_prog *fp_old, unsigned int size, memcpy(fp, fp_old, fp_old->pages * PAGE_SIZE); fp->pages = size / PAGE_SIZE; - /* We keep fp->work from fp_old around in the new + /* We keep fp->aux from fp_old around in the new * reallocated structure. */ - fp_old->work = NULL; + fp_old->aux = NULL; __bpf_prog_free(fp_old); } @@ -123,7 +124,7 @@ EXPORT_SYMBOL_GPL(bpf_prog_realloc); void __bpf_prog_free(struct bpf_prog *fp) { - kfree(fp->work); + kfree(fp->aux); vfree(fp); } EXPORT_SYMBOL_GPL(__bpf_prog_free); @@ -638,19 +639,19 @@ EXPORT_SYMBOL_GPL(bpf_prog_select_runtime); static void bpf_prog_free_deferred(struct work_struct *work) { - struct bpf_work_struct *ws; + struct bpf_prog_aux *aux; - ws = container_of(work, struct bpf_work_struct, work); - bpf_jit_free(ws->prog); + aux = container_of(work, struct bpf_prog_aux, work); + bpf_jit_free(aux->prog); } /* Free internal BPF program */ void bpf_prog_free(struct bpf_prog *fp) { - struct bpf_work_struct *ws = fp->work; + struct bpf_prog_aux *aux = fp->aux; - INIT_WORK(&ws->work, bpf_prog_free_deferred); - ws->prog = fp; - schedule_work(&ws->work); + INIT_WORK(&aux->work, bpf_prog_free_deferred); + aux->prog = fp; + schedule_work(&aux->work); } EXPORT_SYMBOL_GPL(bpf_prog_free); diff --git a/kernel/bpf/syscall.c b/kernel/bpf/syscall.c index f94349ecaf61..0afb4eaa1887 100644 --- a/kernel/bpf/syscall.c +++ b/kernel/bpf/syscall.c @@ -14,6 +14,8 @@ #include <linux/slab.h> #include <linux/anon_inodes.h> #include <linux/file.h> +#include <linux/license.h> +#include <linux/filter.h> static LIST_HEAD(bpf_map_types); @@ -334,6 +336,166 @@ err_put: return err; } +static LIST_HEAD(bpf_prog_types); + +static int find_prog_type(enum bpf_prog_type type, struct bpf_prog *prog) +{ + struct bpf_prog_type_list *tl; + + list_for_each_entry(tl, &bpf_prog_types, list_node) { + if (tl->type == type) { + prog->aux->ops = tl->ops; + prog->aux->prog_type = type; + return 0; + } + } + return -EINVAL; +} + +void bpf_register_prog_type(struct bpf_prog_type_list *tl) +{ + list_add(&tl->list_node, &bpf_prog_types); +} + +/* drop refcnt on maps used by eBPF program and free auxilary data */ +static void free_used_maps(struct bpf_prog_aux *aux) +{ + int i; + + for (i = 0; i < aux->used_map_cnt; i++) + bpf_map_put(aux->used_maps[i]); + + kfree(aux->used_maps); +} + +void bpf_prog_put(struct bpf_prog *prog) +{ + if (atomic_dec_and_test(&prog->aux->refcnt)) { + free_used_maps(prog->aux); + bpf_prog_free(prog); + } +} + +static int bpf_prog_release(struct inode *inode, struct file *filp) +{ + struct bpf_prog *prog = filp->private_data; + + bpf_prog_put(prog); + return 0; +} + +static const struct file_operations bpf_prog_fops = { + .release = bpf_prog_release, +}; + +static struct bpf_prog *get_prog(struct fd f) +{ + struct bpf_prog *prog; + + if (!f.file) + return ERR_PTR(-EBADF); + + if (f.file->f_op != &bpf_prog_fops) { + fdput(f); + return ERR_PTR(-EINVAL); + } + + prog = f.file->private_data; + + return prog; +} + +/* called by sockets/tracing/seccomp before attaching program to an event + * pairs with bpf_prog_put() + */ +struct bpf_prog *bpf_prog_get(u32 ufd) +{ + struct fd f = fdget(ufd); + struct bpf_prog *prog; + + prog = get_prog(f); + + if (IS_ERR(prog)) + return prog; + + atomic_inc(&prog->aux->refcnt); + fdput(f); + return prog; +} + +/* last field in 'union bpf_attr' used by this command */ +#define BPF_PROG_LOAD_LAST_FIELD license + +static int bpf_prog_load(union bpf_attr *attr) +{ + enum bpf_prog_type type = attr->prog_type; + struct bpf_prog *prog; + int err; + char license[128]; + bool is_gpl; + + if (CHECK_ATTR(BPF_PROG_LOAD)) + return -EINVAL; + + /* copy eBPF program license from user space */ + if (strncpy_from_user(license, u64_to_ptr(attr->license), + sizeof(license) - 1) < 0) + return -EFAULT; + license[sizeof(license) - 1] = 0; + + /* eBPF programs must be GPL compatible to use GPL-ed functions */ + is_gpl = license_is_gpl_compatible(license); + + if (attr->insn_cnt >= BPF_MAXINSNS) + return -EINVAL; + + /* plain bpf_prog allocation */ + prog = bpf_prog_alloc(bpf_prog_size(attr->insn_cnt), GFP_USER); + if (!prog) + return -ENOMEM; + + prog->len = attr->insn_cnt; + + err = -EFAULT; + if (copy_from_user(prog->insns, u64_to_ptr(attr->insns), + prog->len * sizeof(struct bpf_insn)) != 0) + goto free_prog; + + prog->orig_prog = NULL; + prog->jited = false; + + atomic_set(&prog->aux->refcnt, 1); + prog->aux->is_gpl_compatible = is_gpl; + + /* find program type: socket_filter vs tracing_filter */ + err = find_prog_type(type, prog); + if (err < 0) + goto free_prog; + + /* run eBPF verifier */ + /* err = bpf_check(prog, tb); */ + + if (err < 0) + goto free_used_maps; + + /* eBPF program is ready to be JITed */ + bpf_prog_select_runtime(prog); + + err = anon_inode_getfd("bpf-prog", &bpf_prog_fops, prog, O_RDWR | O_CLOEXEC); + + if (err < 0) + /* failed to allocate fd */ + goto free_used_maps; + + return err; + +free_used_maps: + free_used_maps(prog->aux); +free_prog: + bpf_prog_free(prog); + return err; +} + SYSCALL_DEFINE3(bpf, int, cmd, union bpf_attr __user *, uattr, unsigned int, size) { union bpf_attr attr = {}; @@ -395,6 +557,9 @@ SYSCALL_DEFINE3(bpf, int, cmd, union bpf_attr __user *, uattr, unsigned int, siz case BPF_MAP_GET_NEXT_KEY: err = map_get_next_key(&attr); break; + case BPF_PROG_LOAD: + err = bpf_prog_load(&attr); + break; default: err = -EINVAL; break; |