From: Alexei Starovoitov <ast@plumgrid.com>
To: "David S. Miller" <davem@davemloft.net>
Cc: Ingo Molnar <mingo@kernel.org>,
Linus Torvalds <torvalds@linux-foundation.org>,
Andy Lutomirski <luto@amacapital.net>,
Steven Rostedt <rostedt@goodmis.org>,
Daniel Borkmann <dborkman@redhat.com>,
Chema Gonzalez <chema@google.com>,
Eric Dumazet <edumazet@google.com>,
Peter Zijlstra <a.p.zijlstra@chello.nl>,
Brendan Gregg <brendan.d.gregg@gmail.com>,
Namhyung Kim <namhyung@kernel.org>,
"H. Peter Anvin" <hpa@zytor.com>,
Andrew Morton <akpm@linux-foundation.org>,
Kees Cook <keescook@chromium.org>,
linux-api@vger.kernel.org, netdev@vger.kernel.org,
linux-kernel@vger.kernel.org
Subject: [PATCH v5 net-next 16/29] bpf: allow eBPF programs to use maps
Date: Sun, 24 Aug 2014 13:21:17 -0700 [thread overview]
Message-ID: <1408911690-7598-17-git-send-email-ast@plumgrid.com> (raw)
In-Reply-To: <1408911690-7598-1-git-send-email-ast@plumgrid.com>
expose bpf_map_lookup_elem(), bpf_map_update_elem(), bpf_map_delete_elem()
map accessors to eBPF programs
Signed-off-by: Alexei Starovoitov <ast@plumgrid.com>
---
include/linux/bpf.h | 5 ++++
include/uapi/linux/bpf.h | 3 ++
kernel/bpf/syscall.c | 68 ++++++++++++++++++++++++++++++++++++++++++++++
3 files changed, 76 insertions(+)
diff --git a/include/linux/bpf.h b/include/linux/bpf.h
index 4d99c62c6cea..e811e294b59a 100644
--- a/include/linux/bpf.h
+++ b/include/linux/bpf.h
@@ -132,4 +132,9 @@ struct bpf_prog *bpf_prog_get(u32 ufd);
/* verify correctness of eBPF program */
int bpf_check(struct bpf_prog *fp, struct nlattr *tb[BPF_PROG_ATTR_MAX + 1]);
+/* in-kernel helper functions called from eBPF programs */
+u64 bpf_map_lookup_elem(u64 r1, u64 r2, u64 r3, u64 r4, u64 r5);
+u64 bpf_map_update_elem(u64 r1, u64 r2, u64 r3, u64 r4, u64 r5);
+u64 bpf_map_delete_elem(u64 r1, u64 r2, u64 r3, u64 r4, u64 r5);
+
#endif /* _LINUX_BPF_H */
diff --git a/include/uapi/linux/bpf.h b/include/uapi/linux/bpf.h
index 63284088aa48..8e4fd3f1c3ec 100644
--- a/include/uapi/linux/bpf.h
+++ b/include/uapi/linux/bpf.h
@@ -404,6 +404,9 @@ enum bpf_prog_type {
*/
enum bpf_func_id {
BPF_FUNC_unspec,
+ BPF_FUNC_map_lookup_elem, /* void *map_lookup_elem(&map, &key) */
+ BPF_FUNC_map_update_elem, /* int map_update_elem(&map, &key, &value) */
+ BPF_FUNC_map_delete_elem, /* int map_delete_elem(&map, &key) */
__BPF_FUNC_MAX_ID,
};
diff --git a/kernel/bpf/syscall.c b/kernel/bpf/syscall.c
index 60cb760cb423..009fe8c77a0b 100644
--- a/kernel/bpf/syscall.c
+++ b/kernel/bpf/syscall.c
@@ -588,3 +588,71 @@ SYSCALL_DEFINE5(bpf, int, cmd, unsigned long, arg2, unsigned long, arg3,
return -EINVAL;
}
}
+
+/* called from eBPF program under rcu lock
+ *
+ * if kernel subsystem is allowing eBPF programs to call this function,
+ * inside its own verifier_ops->get_func_proto() callback it should return
+ * (struct bpf_func_proto) {
+ * .ret_type = RET_PTR_TO_MAP_VALUE_OR_NULL,
+ * .arg1_type = ARG_CONST_MAP_PTR,
+ * .arg2_type = ARG_PTR_TO_MAP_KEY,
+ * }
+ * so that eBPF verifier properly checks the arguments
+ */
+u64 bpf_map_lookup_elem(u64 r1, u64 r2, u64 r3, u64 r4, u64 r5)
+{
+ struct bpf_map *map = (struct bpf_map *) (unsigned long) r1;
+ void *key = (void *) (unsigned long) r2;
+ void *value;
+
+ WARN_ON_ONCE(!rcu_read_lock_held());
+
+ value = map->ops->map_lookup_elem(map, key);
+
+ return (unsigned long) value;
+}
+
+/* called from eBPF program under rcu lock
+ *
+ * if kernel subsystem is allowing eBPF programs to call this function,
+ * inside its own verifier_ops->get_func_proto() callback it should return
+ * (struct bpf_func_proto) {
+ * .ret_type = RET_INTEGER,
+ * .arg1_type = ARG_CONST_MAP_PTR,
+ * .arg2_type = ARG_PTR_TO_MAP_KEY,
+ * .arg3_type = ARG_PTR_TO_MAP_VALUE,
+ * }
+ * so that eBPF verifier properly checks the arguments
+ */
+u64 bpf_map_update_elem(u64 r1, u64 r2, u64 r3, u64 r4, u64 r5)
+{
+ struct bpf_map *map = (struct bpf_map *) (unsigned long) r1;
+ void *key = (void *) (unsigned long) r2;
+ void *value = (void *) (unsigned long) r3;
+
+ WARN_ON_ONCE(!rcu_read_lock_held());
+
+ return map->ops->map_update_elem(map, key, value);
+}
+
+/* called from eBPF program under rcu lock
+ *
+ * if kernel subsystem is allowing eBPF programs to call this function,
+ * inside its own verifier_ops->get_func_proto() callback it should return
+ * (struct bpf_func_proto) {
+ * .ret_type = RET_INTEGER,
+ * .arg1_type = ARG_CONST_MAP_PTR,
+ * .arg2_type = ARG_PTR_TO_MAP_KEY,
+ * }
+ * so that eBPF verifier properly checks the arguments
+ */
+u64 bpf_map_delete_elem(u64 r1, u64 r2, u64 r3, u64 r4, u64 r5)
+{
+ struct bpf_map *map = (struct bpf_map *) (unsigned long) r1;
+ void *key = (void *) (unsigned long) r2;
+
+ WARN_ON_ONCE(!rcu_read_lock_held());
+
+ return map->ops->map_delete_elem(map, key);
+}
--
1.7.9.5
next prev parent reply other threads:[~2014-08-24 20:27 UTC|newest]
Thread overview: 33+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-08-24 20:21 [PATCH v5 net-next 00/29] BPF syscall, maps, verifier, samples, llvm Alexei Starovoitov
2014-08-24 20:21 ` [PATCH v5 net-next 01/29] bpf: x86: add missing 'shift by register' instructions to x64 eBPF JIT Alexei Starovoitov
2014-08-24 20:21 ` [PATCH v5 net-next 02/29] net: filter: add "load 64-bit immediate" eBPF instruction Alexei Starovoitov
2014-08-24 20:21 ` [PATCH v5 net-next 03/29] net: filter: split filter.h and expose eBPF to user space Alexei Starovoitov
2014-08-24 20:21 ` [PATCH v5 net-next 04/29] bpf: introduce syscall(BPF, ...) and BPF maps Alexei Starovoitov
2014-08-24 20:21 ` [PATCH v5 net-next 05/29] bpf: enable bpf syscall on x64 and i386 Alexei Starovoitov
2014-08-24 20:21 ` [PATCH v5 net-next 06/29] bpf: add lookup/update/delete/iterate methods to BPF maps Alexei Starovoitov
2014-08-25 21:33 ` Cong Wang
2014-08-25 22:07 ` Alexei Starovoitov
2014-08-24 20:21 ` [PATCH v5 net-next 07/29] bpf: add hashtable type of " Alexei Starovoitov
2014-08-24 20:21 ` [PATCH v5 net-next 08/29] bpf: expand BPF syscall with program load/unload Alexei Starovoitov
2014-08-24 20:21 ` [PATCH v5 net-next 09/29] bpf: handle pseudo BPF_CALL insn Alexei Starovoitov
2014-08-24 20:21 ` [PATCH v5 net-next 10/29] bpf: verifier (add docs) Alexei Starovoitov
2014-08-24 20:21 ` [PATCH v5 net-next 11/29] bpf: verifier (add ability to receive verification log) Alexei Starovoitov
2014-08-24 20:21 ` [PATCH v5 net-next 12/29] bpf: handle pseudo BPF_LD_IMM64 insn Alexei Starovoitov
2014-08-24 20:21 ` [PATCH v5 net-next 13/29] bpf: verifier (add branch/goto checks) Alexei Starovoitov
2014-08-24 20:21 ` [PATCH v5 net-next 14/29] bpf: verifier (add verifier core) Alexei Starovoitov
2014-08-24 20:21 ` [PATCH v5 net-next 15/29] bpf: verifier (add state prunning optimization) Alexei Starovoitov
2014-08-24 20:21 ` Alexei Starovoitov [this message]
2014-08-24 20:21 ` [PATCH v5 net-next 17/29] bpf: split eBPF out of NET Alexei Starovoitov
2014-08-24 20:21 ` [PATCH v5 net-next 18/29] tracing: allow eBPF programs to be attached to events Alexei Starovoitov
2014-08-24 20:21 ` [PATCH v5 net-next 19/29] tracing: allow eBPF programs call printk() Alexei Starovoitov
2014-08-24 20:21 ` [PATCH v5 net-next 20/29] tracing: allow eBPF programs to be attached to kprobe/kretprobe Alexei Starovoitov
2014-08-24 20:21 ` [PATCH v5 net-next 21/29] tracing: allow eBPF programs to call ktime_get_ns() and get_current() Alexei Starovoitov
2014-08-24 20:21 ` [PATCH v5 net-next 22/29] samples: bpf: add mini eBPF library to manipulate maps and programs Alexei Starovoitov
2014-08-24 20:21 ` [PATCH v5 net-next 23/29] samples: bpf: example of tracing filters with eBPF Alexei Starovoitov
2014-08-24 20:21 ` [PATCH v5 net-next 24/29] bpf: verifier test Alexei Starovoitov
2014-08-24 20:21 ` [PATCH v5 net-next 25/29] bpf: llvm backend Alexei Starovoitov
2014-08-24 20:21 ` [PATCH v5 net-next 26/29] samples: bpf: elf file loader Alexei Starovoitov
2014-08-24 20:21 ` [PATCH v5 net-next 27/29] samples: bpf: eBPF example in C Alexei Starovoitov
2014-08-24 20:21 ` [PATCH v5 net-next 28/29] samples: bpf: counting " Alexei Starovoitov
2014-08-24 20:21 ` [PATCH v5 net-next 29/29] samples: bpf: IO latency analysis (iosnoop/heatmap) Alexei Starovoitov
2014-08-25 0:39 ` [PATCH v5 net-next 00/29] BPF syscall, maps, verifier, samples, llvm David Miller
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