From: Martin KaFai Lau <kafai@fb.com>
Date: Tue, 22 May 2018 15:03:31 -0700
Subject: bpf: Expose check_uarg_tail_zero()
Patch-mainline: v4.18-rc1
Git-commit: dcab51f19b291d5ee23724c51b0a3a597c16451a
References: bsc#1109837
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 <kafai@fb.com>
Acked-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Thomas Bogendoerfer <tbogendoerfer@suse.de>
---
include/linux/bpf.h | 2 ++
kernel/bpf/syscall.c | 14 +++++++-------
2 files changed, 9 insertions(+), 7 deletions(-)
--- a/include/linux/bpf.h
+++ b/include/linux/bpf.h
@@ -434,6 +434,8 @@ int bpf_fd_htab_map_update_elem(struct b
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.
--- a/kernel/bpf/syscall.c
+++ b/kernel/bpf/syscall.c
@@ -65,9 +65,9 @@ static const struct bpf_map_ops * const
* 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;
@@ -1727,7 +1727,7 @@ static int bpf_prog_get_info_by_fd(struc
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);
@@ -1826,7 +1826,7 @@ static int bpf_map_get_info_by_fd(struct
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);
@@ -1866,7 +1866,7 @@ static int bpf_btf_get_info_by_fd(struct
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;
@@ -1938,7 +1938,7 @@ SYSCALL_DEFINE3(bpf, int, cmd, union bpf
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));