commit 24701ecea76b0b93bd9667486934ec310825f558
author Daniel Borkmann <daniel@iogearbox.net> Sun Mar 01 12:31:47 2015 +0100
committer David S. Miller <davem@davemloft.net> Sun Mar 01 14:05:19 2015 -0500
tree 7f658077fea363e89643d95fc808236d748b8431
parent 96be4325f443dbbfeb37d2a157675ac0736531a1

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 <daniel@iogearbox.net>
Acked-by: Alexei Starovoitov <ast@plumgrid.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

kernel/bpf/syscall.c

diff --git a/kernel/bpf/syscall.c b/kernel/bpf/syscall.c
index 536edc2..0d69449 100644
--- a/kernel/bpf/syscall.c
+++ b/kernel/bpf/syscall.c
@@ -354,10 +354,11 @@
 	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 @@
 	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 @@
 
 	/* run eBPF verifier */
 	err = bpf_check(prog, attr);
-
 	if (err < 0)
 		goto free_used_maps;
 
@@ -528,7 +528,6 @@
 	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

diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c
index 594d341..bdf4192a 100644
--- a/kernel/bpf/verifier.c
+++ b/kernel/bpf/verifier.c
@@ -852,7 +852,7 @@
 	}
 
 	/* 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 @@
 	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;
 	}