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bpf: remove struct bpf_prog_type_list
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There's no need to have struct bpf_prog_type_list since
it just contains a list_head, the type, and the ops
pointer. Since the types are densely packed and not
actually dynamically registered, it's much easier and
smaller to have an array of type->ops pointer. Also
initialize this array statically to remove code needed
to initialize it.

In order to save duplicating the list, move it to a new
header file and include it in the places needing it.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Acked-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
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Johannes Berg authored and David S. Miller committed Apr 11, 2017
1 parent 98601e8 commit be9370a
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Showing 5 changed files with 44 additions and 122 deletions.
16 changes: 5 additions & 11 deletions include/linux/bpf.h
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Original file line number Diff line number Diff line change
Expand Up @@ -173,12 +173,6 @@ struct bpf_verifier_ops {
union bpf_attr __user *uattr);
};

struct bpf_prog_type_list {
struct list_head list_node;
const struct bpf_verifier_ops *ops;
enum bpf_prog_type type;
};

struct bpf_prog_aux {
atomic_t refcnt;
u32 used_map_cnt;
Expand Down Expand Up @@ -243,7 +237,11 @@ int bpf_prog_test_run_skb(struct bpf_prog *prog, const union bpf_attr *kattr,
#ifdef CONFIG_BPF_SYSCALL
DECLARE_PER_CPU(int, bpf_prog_active);

void bpf_register_prog_type(struct bpf_prog_type_list *tl);
#define BPF_PROG_TYPE(_id, _ops) \
extern const struct bpf_verifier_ops _ops;
#include <linux/bpf_types.h>
#undef BPF_PROG_TYPE

void bpf_register_map_type(struct bpf_map_type_list *tl);

struct bpf_prog *bpf_prog_get(u32 ufd);
Expand Down Expand Up @@ -306,10 +304,6 @@ static inline void bpf_long_memcpy(void *dst, const void *src, u32 size)
/* verify correctness of eBPF program */
int bpf_check(struct bpf_prog **fp, union bpf_attr *attr);
#else
static inline void bpf_register_prog_type(struct bpf_prog_type_list *tl)
{
}

static inline struct bpf_prog *bpf_prog_get(u32 ufd)
{
return ERR_PTR(-EOPNOTSUPP);
Expand Down
18 changes: 18 additions & 0 deletions include/linux/bpf_types.h
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Original file line number Diff line number Diff line change
@@ -0,0 +1,18 @@
/* internal file - do not include directly */

#ifdef CONFIG_NET
BPF_PROG_TYPE(BPF_PROG_TYPE_SOCKET_FILTER, sk_filter_prog_ops)
BPF_PROG_TYPE(BPF_PROG_TYPE_SCHED_CLS, tc_cls_act_prog_ops)
BPF_PROG_TYPE(BPF_PROG_TYPE_SCHED_ACT, tc_cls_act_prog_ops)
BPF_PROG_TYPE(BPF_PROG_TYPE_XDP, xdp_prog_ops)
BPF_PROG_TYPE(BPF_PROG_TYPE_CGROUP_SKB, cg_skb_prog_ops)
BPF_PROG_TYPE(BPF_PROG_TYPE_CGROUP_SOCK, cg_sock_prog_ops)
BPF_PROG_TYPE(BPF_PROG_TYPE_LWT_IN, lwt_inout_prog_ops)
BPF_PROG_TYPE(BPF_PROG_TYPE_LWT_OUT, lwt_inout_prog_ops)
BPF_PROG_TYPE(BPF_PROG_TYPE_LWT_XMIT, lwt_xmit_prog_ops)
#endif
#ifdef CONFIG_BPF_EVENTS
BPF_PROG_TYPE(BPF_PROG_TYPE_KPROBE, kprobe_prog_ops)
BPF_PROG_TYPE(BPF_PROG_TYPE_TRACEPOINT, tracepoint_prog_ops)
BPF_PROG_TYPE(BPF_PROG_TYPE_PERF_EVENT, perf_event_prog_ops)
#endif
27 changes: 11 additions & 16 deletions kernel/bpf/syscall.c
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Original file line number Diff line number Diff line change
Expand Up @@ -573,26 +573,21 @@ static int map_get_next_key(union bpf_attr *attr)
return err;
}

static LIST_HEAD(bpf_prog_types);
static const struct bpf_verifier_ops * const bpf_prog_types[] = {
#define BPF_PROG_TYPE(_id, _ops) \
[_id] = &_ops,
#include <linux/bpf_types.h>
#undef BPF_PROG_TYPE
};

static int find_prog_type(enum bpf_prog_type type, struct bpf_prog *prog)
{
struct bpf_prog_type_list *tl;

list_for_each_entry(tl, &bpf_prog_types, list_node) {
if (tl->type == type) {
prog->aux->ops = tl->ops;
prog->type = type;
return 0;
}
}

return -EINVAL;
}
if (type >= ARRAY_SIZE(bpf_prog_types) || !bpf_prog_types[type])
return -EINVAL;

void bpf_register_prog_type(struct bpf_prog_type_list *tl)
{
list_add(&tl->list_node, &bpf_prog_types);
prog->aux->ops = bpf_prog_types[type];
prog->type = type;
return 0;
}

/* drop refcnt on maps used by eBPF program and free auxilary data */
Expand Down
30 changes: 3 additions & 27 deletions kernel/trace/bpf_trace.c
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Original file line number Diff line number Diff line change
Expand Up @@ -501,16 +501,11 @@ static bool kprobe_prog_is_valid_access(int off, int size, enum bpf_access_type
return true;
}

static const struct bpf_verifier_ops kprobe_prog_ops = {
const struct bpf_verifier_ops kprobe_prog_ops = {
.get_func_proto = kprobe_prog_func_proto,
.is_valid_access = kprobe_prog_is_valid_access,
};

static struct bpf_prog_type_list kprobe_tl __ro_after_init = {
.ops = &kprobe_prog_ops,
.type = BPF_PROG_TYPE_KPROBE,
};

BPF_CALL_5(bpf_perf_event_output_tp, void *, tp_buff, struct bpf_map *, map,
u64, flags, void *, data, u64, size)
{
Expand Down Expand Up @@ -584,16 +579,11 @@ static bool tp_prog_is_valid_access(int off, int size, enum bpf_access_type type
return true;
}

static const struct bpf_verifier_ops tracepoint_prog_ops = {
const struct bpf_verifier_ops tracepoint_prog_ops = {
.get_func_proto = tp_prog_func_proto,
.is_valid_access = tp_prog_is_valid_access,
};

static struct bpf_prog_type_list tracepoint_tl __ro_after_init = {
.ops = &tracepoint_prog_ops,
.type = BPF_PROG_TYPE_TRACEPOINT,
};

static bool pe_prog_is_valid_access(int off, int size, enum bpf_access_type type,
enum bpf_reg_type *reg_type)
{
Expand Down Expand Up @@ -642,22 +632,8 @@ static u32 pe_prog_convert_ctx_access(enum bpf_access_type type,
return insn - insn_buf;
}

static const struct bpf_verifier_ops perf_event_prog_ops = {
const struct bpf_verifier_ops perf_event_prog_ops = {
.get_func_proto = tp_prog_func_proto,
.is_valid_access = pe_prog_is_valid_access,
.convert_ctx_access = pe_prog_convert_ctx_access,
};

static struct bpf_prog_type_list perf_event_tl __ro_after_init = {
.ops = &perf_event_prog_ops,
.type = BPF_PROG_TYPE_PERF_EVENT,
};

static int __init register_kprobe_prog_ops(void)
{
bpf_register_prog_type(&kprobe_tl);
bpf_register_prog_type(&tracepoint_tl);
bpf_register_prog_type(&perf_event_tl);
return 0;
}
late_initcall(register_kprobe_prog_ops);
75 changes: 7 additions & 68 deletions net/core/filter.c
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Original file line number Diff line number Diff line change
Expand Up @@ -3298,116 +3298,55 @@ static u32 xdp_convert_ctx_access(enum bpf_access_type type,
return insn - insn_buf;
}

static const struct bpf_verifier_ops sk_filter_ops = {
const struct bpf_verifier_ops sk_filter_prog_ops = {
.get_func_proto = sk_filter_func_proto,
.is_valid_access = sk_filter_is_valid_access,
.convert_ctx_access = bpf_convert_ctx_access,
};

static const struct bpf_verifier_ops tc_cls_act_ops = {
const struct bpf_verifier_ops tc_cls_act_prog_ops = {
.get_func_proto = tc_cls_act_func_proto,
.is_valid_access = tc_cls_act_is_valid_access,
.convert_ctx_access = tc_cls_act_convert_ctx_access,
.gen_prologue = tc_cls_act_prologue,
.test_run = bpf_prog_test_run_skb,
};

static const struct bpf_verifier_ops xdp_ops = {
const struct bpf_verifier_ops xdp_prog_ops = {
.get_func_proto = xdp_func_proto,
.is_valid_access = xdp_is_valid_access,
.convert_ctx_access = xdp_convert_ctx_access,
.test_run = bpf_prog_test_run_xdp,
};

static const struct bpf_verifier_ops cg_skb_ops = {
const struct bpf_verifier_ops cg_skb_prog_ops = {
.get_func_proto = cg_skb_func_proto,
.is_valid_access = sk_filter_is_valid_access,
.convert_ctx_access = bpf_convert_ctx_access,
.test_run = bpf_prog_test_run_skb,
};

static const struct bpf_verifier_ops lwt_inout_ops = {
const struct bpf_verifier_ops lwt_inout_prog_ops = {
.get_func_proto = lwt_inout_func_proto,
.is_valid_access = lwt_is_valid_access,
.convert_ctx_access = bpf_convert_ctx_access,
.test_run = bpf_prog_test_run_skb,
};

static const struct bpf_verifier_ops lwt_xmit_ops = {
const struct bpf_verifier_ops lwt_xmit_prog_ops = {
.get_func_proto = lwt_xmit_func_proto,
.is_valid_access = lwt_is_valid_access,
.convert_ctx_access = bpf_convert_ctx_access,
.gen_prologue = tc_cls_act_prologue,
.test_run = bpf_prog_test_run_skb,
};

static const struct bpf_verifier_ops cg_sock_ops = {
const struct bpf_verifier_ops cg_sock_prog_ops = {
.get_func_proto = bpf_base_func_proto,
.is_valid_access = sock_filter_is_valid_access,
.convert_ctx_access = sock_filter_convert_ctx_access,
};

static struct bpf_prog_type_list sk_filter_type __ro_after_init = {
.ops = &sk_filter_ops,
.type = BPF_PROG_TYPE_SOCKET_FILTER,
};

static struct bpf_prog_type_list sched_cls_type __ro_after_init = {
.ops = &tc_cls_act_ops,
.type = BPF_PROG_TYPE_SCHED_CLS,
};

static struct bpf_prog_type_list sched_act_type __ro_after_init = {
.ops = &tc_cls_act_ops,
.type = BPF_PROG_TYPE_SCHED_ACT,
};

static struct bpf_prog_type_list xdp_type __ro_after_init = {
.ops = &xdp_ops,
.type = BPF_PROG_TYPE_XDP,
};

static struct bpf_prog_type_list cg_skb_type __ro_after_init = {
.ops = &cg_skb_ops,
.type = BPF_PROG_TYPE_CGROUP_SKB,
};

static struct bpf_prog_type_list lwt_in_type __ro_after_init = {
.ops = &lwt_inout_ops,
.type = BPF_PROG_TYPE_LWT_IN,
};

static struct bpf_prog_type_list lwt_out_type __ro_after_init = {
.ops = &lwt_inout_ops,
.type = BPF_PROG_TYPE_LWT_OUT,
};

static struct bpf_prog_type_list lwt_xmit_type __ro_after_init = {
.ops = &lwt_xmit_ops,
.type = BPF_PROG_TYPE_LWT_XMIT,
};

static struct bpf_prog_type_list cg_sock_type __ro_after_init = {
.ops = &cg_sock_ops,
.type = BPF_PROG_TYPE_CGROUP_SOCK
};

static int __init register_sk_filter_ops(void)
{
bpf_register_prog_type(&sk_filter_type);
bpf_register_prog_type(&sched_cls_type);
bpf_register_prog_type(&sched_act_type);
bpf_register_prog_type(&xdp_type);
bpf_register_prog_type(&cg_skb_type);
bpf_register_prog_type(&cg_sock_type);
bpf_register_prog_type(&lwt_in_type);
bpf_register_prog_type(&lwt_out_type);
bpf_register_prog_type(&lwt_xmit_type);

return 0;
}
late_initcall(register_sk_filter_ops);

int sk_detach_filter(struct sock *sk)
{
int ret = -ENOENT;
Expand Down

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