From: Björn Töpel <bjorn.to...@intel.com>
Break up bpf_prog_load into one function that allocates, initializes
and verifies a bpf program, and one that allocates a file descriptor.
The former function will be used in a later commit to load a builtin
BPF program.
Signed-off-by: Björn Töpel <bjorn.to...@intel.com>
---
kernel/bpf/syscall.c | 59 ++++++++++++++++++++++++++------------------
1 file changed, 35 insertions(+), 24 deletions(-)
diff --git a/kernel/bpf/syscall.c b/kernel/bpf/syscall.c
index aa05aa38f4a8..ee1328625330 100644
--- a/kernel/bpf/syscall.c
+++ b/kernel/bpf/syscall.c
@@ -1441,7 +1441,8 @@ bpf_prog_load_check_attach_type(enum bpf_prog_type
prog_type,
/* last field in 'union bpf_attr' used by this command */
#define BPF_PROG_LOAD_LAST_FIELD func_info_cnt
-static int bpf_prog_load(union bpf_attr *attr, union bpf_attr __user *uattr)
+static struct bpf_prog *__bpf_prog_load(union bpf_attr *attr,
+ union bpf_attr __user *uattr)
{
enum bpf_prog_type type = attr->prog_type;
struct bpf_prog *prog;
@@ -1450,45 +1451,45 @@ static int bpf_prog_load(union bpf_attr *attr, union
bpf_attr __user *uattr)
bool is_gpl;
if (CHECK_ATTR(BPF_PROG_LOAD))
- return -EINVAL;
+ return ERR_PTR(-EINVAL);
if (attr->prog_flags & ~(BPF_F_STRICT_ALIGNMENT | BPF_F_ANY_ALIGNMENT))
- return -EINVAL;
+ return ERR_PTR(-EINVAL);
if (!IS_ENABLED(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) &&
(attr->prog_flags & BPF_F_ANY_ALIGNMENT) &&
!capable(CAP_SYS_ADMIN))
- return -EPERM;
+ return ERR_PTR(-EPERM);
/* copy eBPF program license from user space */
if (strncpy_from_user(license, u64_to_user_ptr(attr->license),
sizeof(license) - 1) < 0)
- return -EFAULT;
+ return ERR_PTR(-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 == 0 || attr->insn_cnt > BPF_MAXINSNS)
- return -E2BIG;
+ return ERR_PTR(-E2BIG);
if (type == BPF_PROG_TYPE_KPROBE &&
attr->kern_version != LINUX_VERSION_CODE)
- return -EINVAL;
+ return ERR_PTR(-EINVAL);
if (type != BPF_PROG_TYPE_SOCKET_FILTER &&
type != BPF_PROG_TYPE_CGROUP_SKB &&
!capable(CAP_SYS_ADMIN))
- return -EPERM;
+ return ERR_PTR(-EPERM);
bpf_prog_load_fixup_attach_type(attr);
if (bpf_prog_load_check_attach_type(type, attr->expected_attach_type))
- return -EINVAL;
+ return ERR_PTR(-EINVAL);
/* plain bpf_prog allocation */
prog = bpf_prog_alloc(bpf_prog_size(attr->insn_cnt), GFP_USER);
if (!prog)
- return -ENOMEM;
+ return ERR_PTR(-ENOMEM);
prog->expected_attach_type = attr->expected_attach_type;
@@ -1544,20 +1545,8 @@ static int bpf_prog_load(union bpf_attr *attr, union
bpf_attr __user *uattr)
if (err)
goto free_used_maps;
- err = bpf_prog_new_fd(prog);
- if (err < 0) {
- /* failed to allocate fd.
- * bpf_prog_put() is needed because the above
- * bpf_prog_alloc_id() has published the prog
- * to the userspace and the userspace may
- * have refcnt-ed it through BPF_PROG_GET_FD_BY_ID.
- */
- bpf_prog_put(prog);
- return err;
- }
-
bpf_prog_kallsyms_add(prog);
- return err;
+ return prog;
free_used_maps:
kvfree(prog->aux->func_info);
@@ -1570,7 +1559,29 @@ static int bpf_prog_load(union bpf_attr *attr, union
bpf_attr __user *uattr)
security_bpf_prog_free(prog->aux);
free_prog_nouncharge:
bpf_prog_free(prog);
- return err;
+ return ERR_PTR(err);
+}
+
+static int bpf_prog_load(union bpf_attr *attr, union bpf_attr __user *uattr)
+{
+ struct bpf_prog *prog = __bpf_prog_load(attr, uattr);
+ int fd;
+
+ if (IS_ERR(prog))
+ return PTR_ERR(prog);
+
+ fd = bpf_prog_new_fd(prog);
+ if (fd < 0) {
+ /* failed to allocate fd.
+ * bpf_prog_put() is needed because the above
+ * bpf_prog_alloc_id() has published the prog
+ * to the userspace and the userspace may
+ * have refcnt-ed it through BPF_PROG_GET_FD_BY_ID.
+ */
+ bpf_prog_put(prog);
+ }
+
+ return fd;
}
#define BPF_OBJ_LAST_FIELD file_flags
--
2.19.1
