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authorMartin KaFai Lau <kafai@fb.com>2018-04-19 01:56:01 +0300
committerDaniel Borkmann <daniel@iogearbox.net>2018-04-19 22:46:25 +0300
commitf56a653c1fd13a197076dec4461c656fd2adec73 (patch)
treed6ccb94ff2fa8c17a385e4ca29ec6e4b446829a4 /kernel/bpf/syscall.c
parentb00b8daec828dd59af7d1f7a42acd6e5867f80c6 (diff)
downloadlinux-f56a653c1fd13a197076dec4461c656fd2adec73.tar.xz
bpf: btf: Add BPF_BTF_LOAD command
This patch adds a BPF_BTF_LOAD command which 1) loads and verifies the BTF (implemented in earlier patches) 2) returns a BTF fd to userspace. In the next patch, the BTF fd can be specified during BPF_MAP_CREATE. It currently limits to CAP_SYS_ADMIN. Signed-off-by: Martin KaFai Lau <kafai@fb.com> Acked-by: Alexei Starovoitov <ast@fb.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Diffstat (limited to 'kernel/bpf/syscall.c')
-rw-r--r--kernel/bpf/syscall.c17
1 files changed, 17 insertions, 0 deletions
diff --git a/kernel/bpf/syscall.c b/kernel/bpf/syscall.c
index 4ca46df19c9a..cd8ebadc66eb 100644
--- a/kernel/bpf/syscall.c
+++ b/kernel/bpf/syscall.c
@@ -11,6 +11,7 @@
*/
#include <linux/bpf.h>
#include <linux/bpf_trace.h>
+#include <linux/btf.h>
#include <linux/syscalls.h>
#include <linux/slab.h>
#include <linux/sched/signal.h>
@@ -2023,6 +2024,19 @@ static int bpf_obj_get_info_by_fd(const union bpf_attr *attr,
return err;
}
+#define BPF_BTF_LOAD_LAST_FIELD btf_log_level
+
+static int bpf_btf_load(const union bpf_attr *attr)
+{
+ if (CHECK_ATTR(BPF_BTF_LOAD))
+ return -EINVAL;
+
+ if (!capable(CAP_SYS_ADMIN))
+ return -EPERM;
+
+ return btf_new_fd(attr);
+}
+
SYSCALL_DEFINE3(bpf, int, cmd, union bpf_attr __user *, uattr, unsigned int, size)
{
union bpf_attr attr = {};
@@ -2103,6 +2117,9 @@ SYSCALL_DEFINE3(bpf, int, cmd, union bpf_attr __user *, uattr, unsigned int, siz
case BPF_RAW_TRACEPOINT_OPEN:
err = bpf_raw_tracepoint_open(&attr);
break;
+ case BPF_BTF_LOAD:
+ err = bpf_btf_load(&attr);
+ break;
default:
err = -EINVAL;
break;