From 24701ecea76b0b93bd9667486934ec310825f558 Mon Sep 17 00:00:00 2001 From: Daniel Borkmann Date: Sun, 1 Mar 2015 12:31:47 +0100 Subject: [PATCH] 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: Daniel Borkmann Acked-by: Alexei Starovoitov Signed-off-by: David S. Miller --- include/linux/bpf.h | 4 +--- include/linux/filter.h | 4 +++- kernel/bpf/syscall.c | 7 +++---- kernel/bpf/verifier.c | 4 ++-- net/core/filter.c | 4 ++-- 5 files changed, 11 insertions(+), 12 deletions(-) diff --git a/include/linux/bpf.h b/include/linux/bpf.h index 9c458144cdb4..a1a7ff2df328 100644 --- a/include/linux/bpf.h +++ b/include/linux/bpf.h @@ -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; }; diff --git a/include/linux/filter.h b/include/linux/filter.h index 5e3863d5f666..9ee8c67ea249 100644 --- a/include/linux/filter.h +++ b/include/linux/filter.h @@ -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 */ diff --git a/kernel/bpf/syscall.c b/kernel/bpf/syscall.c index 536edc2be307..0d69449acbd0 100644 --- a/kernel/bpf/syscall.c +++ b/kernel/bpf/syscall.c @@ -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; diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c index 594d341f04db..bdf4192a889b 100644 --- a/kernel/bpf/verifier.c +++ b/kernel/bpf/verifier.c @@ -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; } diff --git a/net/core/filter.c b/net/core/filter.c index 514d4082f326..ff000cb25e0a 100644 --- a/net/core/filter.c +++ b/net/core/filter.c @@ -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; }