bpf: Fix missing bpf_base_func_proto in cgroup_base_func_proto for CGROUP_NET=n

linux-next build bot reported compile issue [1] with one of its
configs. It looks like when we have CONFIG_NET=n and
CONFIG_BPF{,_SYSCALL}=y, we are missing the bpf_base_func_proto
definition (from net/core/filter.c) in cgroup_base_func_proto.

I'm reshuffling the code a bit to make it work. The common helpers
are moved into kernel/bpf/helpers.c and the bpf_base_func_proto is
exported from there.
Also, bpf_get_raw_cpu_id goes into kernel/bpf/core.c akin to existing
bpf_user_rnd_u32.

[1] https://lore.kernel.org/linux-next/CAKH8qBsBvKHswiX1nx40LgO+BGeTmb1NX8tiTttt_0uu6T3dCA@mail.gmail.com/T/#mff8b0c083314c68c2e2ef0211cb11bc20dc13c72

Fixes: 0456ea170c ("bpf: Enable more helpers for BPF_PROG_TYPE_CGROUP_{DEVICE,SYSCTL,SOCKOPT}")
Signed-off-by: Stanislav Fomichev <sdf@google.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Cc: Andrii Nakryiko <andriin@fb.com>
Link: https://lore.kernel.org/bpf/20200424235941.58382-1-sdf@google.com
This commit is contained in:
Stanislav Fomichev 2020-04-24 16:59:41 -07:00 committed by Alexei Starovoitov
parent 745abfaa9e
commit 6890896bd7
5 changed files with 87 additions and 79 deletions

View File

@ -1215,6 +1215,7 @@ int btf_check_type_match(struct bpf_verifier_env *env, struct bpf_prog *prog,
struct bpf_prog *bpf_prog_by_id(u32 id);
const struct bpf_func_proto *bpf_base_func_proto(enum bpf_func_id func_id);
#else /* !CONFIG_BPF_SYSCALL */
static inline struct bpf_prog *bpf_prog_get(u32 ufd)
{
@ -1365,6 +1366,12 @@ static inline struct bpf_prog *bpf_prog_by_id(u32 id)
{
return ERR_PTR(-ENOTSUPP);
}
static inline const struct bpf_func_proto *
bpf_base_func_proto(enum bpf_func_id func_id)
{
return NULL;
}
#endif /* CONFIG_BPF_SYSCALL */
static inline struct bpf_prog *bpf_prog_get_type(u32 ufd,
@ -1531,6 +1538,7 @@ const struct bpf_func_proto *bpf_tracing_func_proto(
/* Shared helpers among cBPF and eBPF. */
void bpf_user_rnd_init_once(void);
u64 bpf_user_rnd_u32(u64 r1, u64 r2, u64 r3, u64 r4, u64 r5);
u64 bpf_get_raw_cpu_id(u64 r1, u64 r2, u64 r3, u64 r4, u64 r5);
#if defined(CONFIG_NET)
bool bpf_sock_common_is_valid_access(int off, int size,

View File

@ -863,8 +863,6 @@ int bpf_prog_create(struct bpf_prog **pfp, struct sock_fprog_kern *fprog);
int bpf_prog_create_from_user(struct bpf_prog **pfp, struct sock_fprog *fprog,
bpf_aux_classic_check_t trans, bool save_orig);
void bpf_prog_destroy(struct bpf_prog *fp);
const struct bpf_func_proto *
bpf_base_func_proto(enum bpf_func_id func_id);
int sk_attach_filter(struct sock_fprog *fprog, struct sock *sk);
int sk_attach_bpf(u32 ufd, struct sock *sk);

View File

@ -2136,6 +2136,11 @@ BPF_CALL_0(bpf_user_rnd_u32)
return res;
}
BPF_CALL_0(bpf_get_raw_cpu_id)
{
return raw_smp_processor_id();
}
/* Weak definitions of helper functions in case we don't have bpf syscall. */
const struct bpf_func_proto bpf_map_lookup_elem_proto __weak;
const struct bpf_func_proto bpf_map_update_elem_proto __weak;

View File

@ -562,3 +562,76 @@ const struct bpf_func_proto bpf_get_ns_current_pid_tgid_proto = {
.arg3_type = ARG_PTR_TO_UNINIT_MEM,
.arg4_type = ARG_CONST_SIZE,
};
static const struct bpf_func_proto bpf_get_raw_smp_processor_id_proto = {
.func = bpf_get_raw_cpu_id,
.gpl_only = false,
.ret_type = RET_INTEGER,
};
BPF_CALL_5(bpf_event_output_data, void *, ctx, struct bpf_map *, map,
u64, flags, void *, data, u64, size)
{
if (unlikely(flags & ~(BPF_F_INDEX_MASK)))
return -EINVAL;
return bpf_event_output(map, flags, data, size, NULL, 0, NULL);
}
const struct bpf_func_proto bpf_event_output_data_proto = {
.func = bpf_event_output_data,
.gpl_only = true,
.ret_type = RET_INTEGER,
.arg1_type = ARG_PTR_TO_CTX,
.arg2_type = ARG_CONST_MAP_PTR,
.arg3_type = ARG_ANYTHING,
.arg4_type = ARG_PTR_TO_MEM,
.arg5_type = ARG_CONST_SIZE_OR_ZERO,
};
const struct bpf_func_proto *
bpf_base_func_proto(enum bpf_func_id func_id)
{
switch (func_id) {
case BPF_FUNC_map_lookup_elem:
return &bpf_map_lookup_elem_proto;
case BPF_FUNC_map_update_elem:
return &bpf_map_update_elem_proto;
case BPF_FUNC_map_delete_elem:
return &bpf_map_delete_elem_proto;
case BPF_FUNC_map_push_elem:
return &bpf_map_push_elem_proto;
case BPF_FUNC_map_pop_elem:
return &bpf_map_pop_elem_proto;
case BPF_FUNC_map_peek_elem:
return &bpf_map_peek_elem_proto;
case BPF_FUNC_get_prandom_u32:
return &bpf_get_prandom_u32_proto;
case BPF_FUNC_get_smp_processor_id:
return &bpf_get_raw_smp_processor_id_proto;
case BPF_FUNC_get_numa_node_id:
return &bpf_get_numa_node_id_proto;
case BPF_FUNC_tail_call:
return &bpf_tail_call_proto;
case BPF_FUNC_ktime_get_ns:
return &bpf_ktime_get_ns_proto;
default:
break;
}
if (!capable(CAP_SYS_ADMIN))
return NULL;
switch (func_id) {
case BPF_FUNC_spin_lock:
return &bpf_spin_lock_proto;
case BPF_FUNC_spin_unlock:
return &bpf_spin_unlock_proto;
case BPF_FUNC_trace_printk:
return bpf_get_trace_printk_proto();
case BPF_FUNC_jiffies64:
return &bpf_jiffies64_proto;
default:
return NULL;
}
}

View File

@ -256,17 +256,6 @@ BPF_CALL_2(bpf_skb_load_helper_32_no_cache, const struct sk_buff *, skb,
offset);
}
BPF_CALL_0(bpf_get_raw_cpu_id)
{
return raw_smp_processor_id();
}
static const struct bpf_func_proto bpf_get_raw_smp_processor_id_proto = {
.func = bpf_get_raw_cpu_id,
.gpl_only = false,
.ret_type = RET_INTEGER,
};
static u32 convert_skb_access(int skb_field, int dst_reg, int src_reg,
struct bpf_insn *insn_buf)
{
@ -4205,26 +4194,6 @@ static const struct bpf_func_proto bpf_get_socket_uid_proto = {
.arg1_type = ARG_PTR_TO_CTX,
};
BPF_CALL_5(bpf_event_output_data, void *, ctx, struct bpf_map *, map, u64, flags,
void *, data, u64, size)
{
if (unlikely(flags & ~(BPF_F_INDEX_MASK)))
return -EINVAL;
return bpf_event_output(map, flags, data, size, NULL, 0, NULL);
}
const struct bpf_func_proto bpf_event_output_data_proto = {
.func = bpf_event_output_data,
.gpl_only = true,
.ret_type = RET_INTEGER,
.arg1_type = ARG_PTR_TO_CTX,
.arg2_type = ARG_CONST_MAP_PTR,
.arg3_type = ARG_ANYTHING,
.arg4_type = ARG_PTR_TO_MEM,
.arg5_type = ARG_CONST_SIZE_OR_ZERO,
};
BPF_CALL_5(bpf_setsockopt, struct bpf_sock_ops_kern *, bpf_sock,
int, level, int, optname, char *, optval, int, optlen)
{
@ -5983,52 +5952,7 @@ bool bpf_helper_changes_pkt_data(void *func)
return false;
}
const struct bpf_func_proto *
bpf_base_func_proto(enum bpf_func_id func_id)
{
switch (func_id) {
case BPF_FUNC_map_lookup_elem:
return &bpf_map_lookup_elem_proto;
case BPF_FUNC_map_update_elem:
return &bpf_map_update_elem_proto;
case BPF_FUNC_map_delete_elem:
return &bpf_map_delete_elem_proto;
case BPF_FUNC_map_push_elem:
return &bpf_map_push_elem_proto;
case BPF_FUNC_map_pop_elem:
return &bpf_map_pop_elem_proto;
case BPF_FUNC_map_peek_elem:
return &bpf_map_peek_elem_proto;
case BPF_FUNC_get_prandom_u32:
return &bpf_get_prandom_u32_proto;
case BPF_FUNC_get_smp_processor_id:
return &bpf_get_raw_smp_processor_id_proto;
case BPF_FUNC_get_numa_node_id:
return &bpf_get_numa_node_id_proto;
case BPF_FUNC_tail_call:
return &bpf_tail_call_proto;
case BPF_FUNC_ktime_get_ns:
return &bpf_ktime_get_ns_proto;
default:
break;
}
if (!capable(CAP_SYS_ADMIN))
return NULL;
switch (func_id) {
case BPF_FUNC_spin_lock:
return &bpf_spin_lock_proto;
case BPF_FUNC_spin_unlock:
return &bpf_spin_unlock_proto;
case BPF_FUNC_trace_printk:
return bpf_get_trace_printk_proto();
case BPF_FUNC_jiffies64:
return &bpf_jiffies64_proto;
default:
return NULL;
}
}
const struct bpf_func_proto bpf_event_output_data_proto __weak;
static const struct bpf_func_proto *
sock_filter_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog)