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Commit 24701ece authored by Daniel Borkmann's avatar Daniel Borkmann Committed by David S. Miller
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ebpf: move read-only fields to bpf_prog and shrink bpf_prog_aux 



is_gpl_compatible and prog_type should be moved directly into bpf_prog
as they stay immutable during bpf_prog's lifetime, are core attributes
and they can be locked as read-only later on via bpf_prog_select_runtime().

With a bit of rearranging, this also allows us to shrink bpf_prog_aux
to exactly 1 cacheline.

Signed-off-by: default avatarDaniel Borkmann <daniel@iogearbox.net>
Acked-by: default avatarAlexei Starovoitov <ast@plumgrid.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 96be4325

include/linux/bpf.h

+1 −3
Original line number Diff line number Diff line
@@ -117,11 +117,9 @@ struct bpf_prog; 


struct bpf_prog_aux {

	atomic_t refcnt;

	bool is_gpl_compatible;

	enum bpf_prog_type prog_type;

	u32 used_map_cnt;

	const struct bpf_verifier_ops *ops;

	struct bpf_map **used_maps;

	u32 used_map_cnt;

	struct bpf_prog *prog;

	struct work_struct work;

};

include/linux/filter.h

+3 −1
Original line number Diff line number Diff line
@@ -308,9 +308,11 @@ struct bpf_binary_header { 
struct bpf_prog {

	u16			pages;		/* Number of allocated pages */

	bool			jited;		/* Is our filter JIT'ed? */

	bool			gpl_compatible;	/* Is our filter GPL compatible? */

	u32			len;		/* Number of filter blocks */

	struct sock_fprog_kern	*orig_prog;	/* Original BPF program */

	enum bpf_prog_type	type;		/* Type of BPF program */

	struct bpf_prog_aux	*aux;		/* Auxiliary fields */

	struct sock_fprog_kern	*orig_prog;	/* Original BPF program */

	unsigned int		(*bpf_func)(const struct sk_buff *skb,

					    const struct bpf_insn *filter);

	/* Instructions for interpreter */

kernel/bpf/syscall.c

+3 −4
Original line number Diff line number Diff line
@@ -354,10 +354,11 @@ static int find_prog_type(enum bpf_prog_type type, struct bpf_prog *prog) 
	list_for_each_entry(tl, &bpf_prog_types, list_node) {

		if (tl->type == type) {

			prog->aux->ops = tl->ops;

			prog->aux->prog_type = type;

			prog->type = type;

			return 0;

		}

	}



	return -EINVAL;

}
@@ -508,7 +509,7 @@ static int bpf_prog_load(union bpf_attr *attr) 
	prog->jited = false;



	atomic_set(&prog->aux->refcnt, 1);

	prog->aux->is_gpl_compatible = is_gpl;

	prog->gpl_compatible = is_gpl;



	/* find program type: socket_filter vs tracing_filter */

	err = find_prog_type(type, prog);
@@ -517,7 +518,6 @@ static int bpf_prog_load(union bpf_attr *attr) 


	/* run eBPF verifier */

	err = bpf_check(prog, attr);



	if (err < 0)

		goto free_used_maps;
@@ -528,7 +528,6 @@ static int bpf_prog_load(union bpf_attr *attr) 
	bpf_prog_select_runtime(prog);



	err = anon_inode_getfd("bpf-prog", &bpf_prog_fops, prog, O_RDWR | O_CLOEXEC);



	if (err < 0)

		/* failed to allocate fd */

		goto free_used_maps;

kernel/bpf/verifier.c

+2 −2
Original line number Diff line number Diff line
@@ -852,7 +852,7 @@ static int check_call(struct verifier_env *env, int func_id) 
	}



	/* eBPF programs must be GPL compatible to use GPL-ed functions */

	if (!env->prog->aux->is_gpl_compatible && fn->gpl_only) {

	if (!env->prog->gpl_compatible && fn->gpl_only) {

		verbose("cannot call GPL only function from proprietary program\n");

		return -EINVAL;

	}
@@ -1205,7 +1205,7 @@ static int check_ld_abs(struct verifier_env *env, struct bpf_insn *insn) 
	struct reg_state *reg;

	int i, err;



	if (!may_access_skb(env->prog->aux->prog_type)) {

	if (!may_access_skb(env->prog->type)) {

		verbose("BPF_LD_ABS|IND instructions not allowed for this program type\n");

		return -EINVAL;

	}

net/core/filter.c

+2 −2
Original line number Diff line number Diff line
@@ -814,7 +814,7 @@ static void bpf_release_orig_filter(struct bpf_prog *fp) 


static void __bpf_prog_release(struct bpf_prog *prog)

{

	if (prog->aux->prog_type == BPF_PROG_TYPE_SOCKET_FILTER) {

	if (prog->type == BPF_PROG_TYPE_SOCKET_FILTER) {

		bpf_prog_put(prog);

	} else {

		bpf_release_orig_filter(prog);
@@ -1105,7 +1105,7 @@ int sk_attach_bpf(u32 ufd, struct sock *sk) 
	if (IS_ERR(prog))

		return PTR_ERR(prog);



	if (prog->aux->prog_type != BPF_PROG_TYPE_SOCKET_FILTER) {

	if (prog->type != BPF_PROG_TYPE_SOCKET_FILTER) {

		bpf_prog_put(prog);

		return -EINVAL;

	}