diff options
| -rw-r--r-- | include/linux/bpf.h | 11 | ||||
| -rw-r--r-- | kernel/bpf/core.c | 16 | ||||
| -rw-r--r-- | kernel/bpf/syscall.c | 36 |
3 files changed, 52 insertions, 11 deletions
diff --git a/include/linux/bpf.h b/include/linux/bpf.h index 201eb483c46f..f74ae68086dc 100644 --- a/include/linux/bpf.h +++ b/include/linux/bpf.h @@ -238,6 +238,8 @@ struct bpf_prog * __must_check bpf_prog_add(struct bpf_prog *prog, int i); void bpf_prog_sub(struct bpf_prog *prog, int i); struct bpf_prog * __must_check bpf_prog_inc(struct bpf_prog *prog); void bpf_prog_put(struct bpf_prog *prog); +int __bpf_prog_charge(struct user_struct *user, u32 pages); +void __bpf_prog_uncharge(struct user_struct *user, u32 pages); struct bpf_map *bpf_map_get_with_uref(u32 ufd); struct bpf_map *__bpf_map_get(struct fd f); @@ -318,6 +320,15 @@ static inline struct bpf_prog * __must_check bpf_prog_inc(struct bpf_prog *prog) { return ERR_PTR(-EOPNOTSUPP); } + +static inline int __bpf_prog_charge(struct user_struct *user, u32 pages) +{ + return 0; +} + +static inline void __bpf_prog_uncharge(struct user_struct *user, u32 pages) +{ +} #endif /* CONFIG_BPF_SYSCALL */ /* verifier prototypes for helper functions called from eBPF programs */ diff --git a/kernel/bpf/core.c b/kernel/bpf/core.c index 75c08b8068d6..1eb4f1303756 100644 --- a/kernel/bpf/core.c +++ b/kernel/bpf/core.c @@ -105,19 +105,29 @@ struct bpf_prog *bpf_prog_realloc(struct bpf_prog *fp_old, unsigned int size, gfp_t gfp_flags = GFP_KERNEL | __GFP_HIGHMEM | __GFP_ZERO | gfp_extra_flags; struct bpf_prog *fp; + u32 pages, delta; + int ret; BUG_ON(fp_old == NULL); size = round_up(size, PAGE_SIZE); - if (size <= fp_old->pages * PAGE_SIZE) + pages = size / PAGE_SIZE; + if (pages <= fp_old->pages) return fp_old; + delta = pages - fp_old->pages; + ret = __bpf_prog_charge(fp_old->aux->user, delta); + if (ret) + return NULL; + fp = __vmalloc(size, gfp_flags, PAGE_KERNEL); - if (fp != NULL) { + if (fp == NULL) { + __bpf_prog_uncharge(fp_old->aux->user, delta); + } else { kmemcheck_annotate_bitfield(fp, meta); memcpy(fp, fp_old, fp_old->pages * PAGE_SIZE); - fp->pages = size / PAGE_SIZE; + fp->pages = pages; fp->aux->prog = fp; /* We keep fp->aux from fp_old around in the new diff --git a/kernel/bpf/syscall.c b/kernel/bpf/syscall.c index 35d674c1f12e..e89acea22ecf 100644 --- a/kernel/bpf/syscall.c +++ b/kernel/bpf/syscall.c @@ -615,19 +615,39 @@ static void free_used_maps(struct bpf_prog_aux *aux) kfree(aux->used_maps); } +int __bpf_prog_charge(struct user_struct *user, u32 pages) +{ + unsigned long memlock_limit = rlimit(RLIMIT_MEMLOCK) >> PAGE_SHIFT; + unsigned long user_bufs; + + if (user) { + user_bufs = atomic_long_add_return(pages, &user->locked_vm); + if (user_bufs > memlock_limit) { + atomic_long_sub(pages, &user->locked_vm); + return -EPERM; + } + } + + return 0; +} + +void __bpf_prog_uncharge(struct user_struct *user, u32 pages) +{ + if (user) + atomic_long_sub(pages, &user->locked_vm); +} + static int bpf_prog_charge_memlock(struct bpf_prog *prog) { struct user_struct *user = get_current_user(); - unsigned long memlock_limit; - - memlock_limit = rlimit(RLIMIT_MEMLOCK) >> PAGE_SHIFT; + int ret; - atomic_long_add(prog->pages, &user->locked_vm); - if (atomic_long_read(&user->locked_vm) > memlock_limit) { - atomic_long_sub(prog->pages, &user->locked_vm); + ret = __bpf_prog_charge(user, prog->pages); + if (ret) { free_uid(user); - return -EPERM; + return ret; } + prog->aux->user = user; return 0; } @@ -636,7 +656,7 @@ static void bpf_prog_uncharge_memlock(struct bpf_prog *prog) { struct user_struct *user = prog->aux->user; - atomic_long_sub(prog->pages, &user->locked_vm); + __bpf_prog_uncharge(user, prog->pages); free_uid(user); } |