From: Martin KaFai Lau <kafai@fb•com>
To: <netdev@vger•kernel.org>
Cc: Daniel Borkmann <daniel@iogearbox•net>,
Hannes Frederic Sowa <hannes@stressinduktion•org>,
Alexei Starovoitov <ast@fb•com>, <kernel-team@fb•com>
Subject: [RFC net-next 1/2] bpf: Introduce bpf_prog ID
Date: Wed, 26 Apr 2017 23:24:48 -0700 [thread overview]
Message-ID: <20170427062449.80290-2-kafai@fb.com> (raw)
In-Reply-To: <20170427062449.80290-1-kafai@fb.com>
The ID is generated by the existing idr_alloc_cyclic().
This patch also adds BPF_PROG_GET_NEXT_ID to allow userspace to iterate
all bpf_prog id(s). The API is trying to be consistent with the
existing BPF_MAP_GET_NEXT_KEY.
Signed-off-by: Martin KaFai Lau <kafai@fb•com>
---
include/linux/filter.h | 1 +
include/uapi/linux/bpf.h | 6 ++++++
kernel/bpf/syscall.c | 47 ++++++++++++++++++++++++++++++++++++++++++++++-
3 files changed, 53 insertions(+), 1 deletion(-)
diff --git a/include/linux/filter.h b/include/linux/filter.h
index 9a7786db14fa..6eeeb83c4013 100644
--- a/include/linux/filter.h
+++ b/include/linux/filter.h
@@ -417,6 +417,7 @@ struct bpf_prog {
kmemcheck_bitfield_end(meta);
enum bpf_prog_type type; /* Type of BPF program */
u32 len; /* Number of filter blocks */
+ u32 id;
u8 tag[BPF_TAG_SIZE];
struct bpf_prog_aux *aux; /* Auxiliary fields */
struct sock_fprog_kern *orig_prog; /* Original BPF program */
diff --git a/include/uapi/linux/bpf.h b/include/uapi/linux/bpf.h
index e553529929f6..270f501c5597 100644
--- a/include/uapi/linux/bpf.h
+++ b/include/uapi/linux/bpf.h
@@ -82,6 +82,7 @@ enum bpf_cmd {
BPF_PROG_ATTACH,
BPF_PROG_DETACH,
BPF_PROG_TEST_RUN,
+ BPF_PROG_GET_NEXT_ID,
};
enum bpf_map_type {
@@ -201,6 +202,11 @@ union bpf_attr {
__u32 repeat;
__u32 duration;
} test;
+
+ struct { /* anonymous struct used by BPF_PROG_GET_NEXT_ID */
+ __u32 start_id;
+ __aligned_u64 next_id;
+ };
} __attribute__((aligned(8)));
/* BPF helper function descriptions:
diff --git a/kernel/bpf/syscall.c b/kernel/bpf/syscall.c
index 13642c73dca0..6a654e17bd3c 100644
--- a/kernel/bpf/syscall.c
+++ b/kernel/bpf/syscall.c
@@ -22,8 +22,11 @@
#include <linux/filter.h>
#include <linux/version.h>
#include <linux/kernel.h>
+#include <linux/idr.h>
DEFINE_PER_CPU(int, bpf_prog_active);
+DEFINE_IDR(prog_idr);
+DEFINE_SPINLOCK(prog_idr_lock);
int sysctl_unprivileged_bpf_disabled __read_mostly;
@@ -663,6 +666,9 @@ static void __bpf_prog_put_rcu(struct rcu_head *rcu)
void bpf_prog_put(struct bpf_prog *prog)
{
if (atomic_dec_and_test(&prog->aux->refcnt)) {
+ spin_lock(&prog_idr_lock);
+ idr_remove(&prog_idr, prog->id);
+ spin_unlock(&prog_idr_lock);
trace_bpf_prog_put_rcu(prog);
bpf_prog_kallsyms_del(prog);
call_rcu(&prog->aux->rcu, __bpf_prog_put_rcu);
@@ -790,7 +796,7 @@ static int bpf_prog_load(union bpf_attr *attr)
{
enum bpf_prog_type type = attr->prog_type;
struct bpf_prog *prog;
- int err;
+ int err, id;
char license[128];
bool is_gpl;
@@ -848,6 +854,15 @@ static int bpf_prog_load(union bpf_attr *attr)
if (err < 0)
goto free_used_maps;
+ spin_lock(&prog_idr_lock);
+ id = idr_alloc_cyclic(&prog_idr, prog, 1, INT_MAX, GFP_USER);
+ spin_unlock(&prog_idr_lock);
+ if (id < 0) {
+ err = id;
+ goto free_used_maps;
+ }
+ prog->id = id;
+
/* eBPF program is ready to be JITed */
prog = bpf_prog_select_runtime(prog, &err);
if (err < 0)
@@ -995,6 +1010,33 @@ static int bpf_prog_test_run(const union bpf_attr *attr,
return ret;
}
+#define BPF_PROG_GET_NEXT_ID_LAST_FIELD next_id
+
+static int bpf_prog_get_next_id(union bpf_attr *attr)
+{
+ u64 __user *unext_id = u64_to_user_ptr(attr->next_id);
+ u32 next_id = attr->start_id;
+ struct bpf_prog *prog;
+
+ if (CHECK_ATTR(BPF_PROG_GET_NEXT_ID))
+ return -EINVAL;
+
+ if (next_id++ >= INT_MAX)
+ return -EINVAL;
+
+ spin_lock(&prog_idr_lock);
+ prog = idr_get_next(&prog_idr, &next_id);
+ spin_unlock(&prog_idr_lock);
+
+ if (!prog)
+ return -ENOENT;
+
+ if (copy_to_user(unext_id, &next_id, sizeof(next_id)))
+ return -EFAULT;
+
+ return 0;
+}
+
SYSCALL_DEFINE3(bpf, int, cmd, union bpf_attr __user *, uattr, unsigned int, size)
{
union bpf_attr attr = {};
@@ -1072,6 +1114,9 @@ SYSCALL_DEFINE3(bpf, int, cmd, union bpf_attr __user *, uattr, unsigned int, siz
case BPF_PROG_TEST_RUN:
err = bpf_prog_test_run(&attr, uattr);
break;
+ case BPF_PROG_GET_NEXT_ID:
+ err = bpf_prog_get_next_id(&attr);
+ break;
default:
err = -EINVAL;
break;
--
2.9.3
next prev parent reply other threads:[~2017-04-27 6:24 UTC|newest]
Thread overview: 18+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-04-27 6:24 [RFC net-next 0/2] Introduce bpf_prog ID and iteration Martin KaFai Lau
2017-04-27 6:24 ` Martin KaFai Lau [this message]
2017-05-15 8:14 ` [lkp-robot] [bpf] de05014aba: BUG:sleeping_function_called_from_invalid_context_at_mm/slab.h kernel test robot
2017-05-15 18:57 ` David Miller
2017-04-27 6:24 ` [RFC net-next 2/2] bpf: Test for bpf_prog ID and BPF_PROG_GET_NEXT_ID Martin KaFai Lau
2017-04-27 7:23 ` Alexander Alemayhu
2017-04-27 21:10 ` Martin KaFai Lau
2017-04-27 13:36 ` [RFC net-next 0/2] Introduce bpf_prog ID and iteration Hannes Frederic Sowa
2017-04-27 21:14 ` Martin KaFai Lau
2017-04-28 1:11 ` prog ID and next steps. Was: " Alexei Starovoitov
2017-04-28 11:50 ` Hannes Frederic Sowa
2017-04-28 18:24 ` Daniel Borkmann
2017-04-28 18:51 ` Hannes Frederic Sowa
2017-04-28 18:57 ` Hannes Frederic Sowa
2017-04-28 19:31 ` Alexei Starovoitov
2017-04-28 21:13 ` Hannes Frederic Sowa
2017-04-30 2:06 ` Alexei Starovoitov
2017-04-30 2:36 ` Hannes Frederic Sowa
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