From dcab51f19b291d5ee23724c51b0a3a597c16451a Mon Sep 17 00:00:00 2001 From: Martin KaFai Lau Date: Tue, 22 May 2018 15:03:31 -0700 Subject: [PATCH] bpf: Expose check_uarg_tail_zero() This patch exposes check_uarg_tail_zero() which will be reused by a later BTF patch. Its name is changed to bpf_check_uarg_tail_zero(). Signed-off-by: Martin KaFai Lau Acked-by: Yonghong Song Signed-off-by: Daniel Borkmann --- include/linux/bpf.h | 2 ++ kernel/bpf/syscall.c | 14 +++++++------- 2 files changed, 9 insertions(+), 7 deletions(-) diff --git a/include/linux/bpf.h b/include/linux/bpf.h index ed0122b45b63..f6fe3c719ca8 100644 --- a/include/linux/bpf.h +++ b/include/linux/bpf.h @@ -463,6 +463,8 @@ int bpf_fd_htab_map_update_elem(struct bpf_map *map, struct file *map_file, int bpf_fd_htab_map_lookup_elem(struct bpf_map *map, void *key, u32 *value); int bpf_get_file_flag(int flags); +int bpf_check_uarg_tail_zero(void __user *uaddr, size_t expected_size, + size_t actual_size); /* memcpy that is used with 8-byte aligned pointers, power-of-8 size and * forced to use 'long' read/writes to try to atomically copy long counters. diff --git a/kernel/bpf/syscall.c b/kernel/bpf/syscall.c index bfcde949c7f8..2b29ef84ded3 100644 --- a/kernel/bpf/syscall.c +++ b/kernel/bpf/syscall.c @@ -65,9 +65,9 @@ static const struct bpf_map_ops * const bpf_map_types[] = { * copy_from_user() call. However, this is not a concern since this function is * meant to be a future-proofing of bits. */ -static int check_uarg_tail_zero(void __user *uaddr, - size_t expected_size, - size_t actual_size) +int bpf_check_uarg_tail_zero(void __user *uaddr, + size_t expected_size, + size_t actual_size) { unsigned char __user *addr; unsigned char __user *end; @@ -1899,7 +1899,7 @@ static int bpf_prog_get_info_by_fd(struct bpf_prog *prog, u32 ulen; int err; - err = check_uarg_tail_zero(uinfo, sizeof(info), info_len); + err = bpf_check_uarg_tail_zero(uinfo, sizeof(info), info_len); if (err) return err; info_len = min_t(u32, sizeof(info), info_len); @@ -1998,7 +1998,7 @@ static int bpf_map_get_info_by_fd(struct bpf_map *map, u32 info_len = attr->info.info_len; int err; - err = check_uarg_tail_zero(uinfo, sizeof(info), info_len); + err = bpf_check_uarg_tail_zero(uinfo, sizeof(info), info_len); if (err) return err; info_len = min_t(u32, sizeof(info), info_len); @@ -2038,7 +2038,7 @@ static int bpf_btf_get_info_by_fd(struct btf *btf, u32 info_len = attr->info.info_len; int err; - err = check_uarg_tail_zero(uinfo, sizeof(*uinfo), info_len); + err = bpf_check_uarg_tail_zero(uinfo, sizeof(*uinfo), info_len); if (err) return err; @@ -2110,7 +2110,7 @@ SYSCALL_DEFINE3(bpf, int, cmd, union bpf_attr __user *, uattr, unsigned int, siz if (sysctl_unprivileged_bpf_disabled && !capable(CAP_SYS_ADMIN)) return -EPERM; - err = check_uarg_tail_zero(uattr, sizeof(attr), size); + err = bpf_check_uarg_tail_zero(uattr, sizeof(attr), size); if (err) return err; size = min_t(u32, size, sizeof(attr));