From 6c4fc209fcf9d27efbaa48368773e4d2bfbd59aa Mon Sep 17 00:00:00 2001 From: Daniel Borkmann Date: Sun, 16 Dec 2018 00:49:47 +0100 Subject: bpf: remove useless version check for prog load Existing libraries and tracing frameworks work around this kernel version check by automatically deriving the kernel version from uname(3) or similar such that the user does not need to do it manually; these workarounds also make the version check useless at the same time. Moreover, most other BPF tracing types enabling bpf_probe_read()-like functionality have /not/ adapted this check, and in general these days it is well understood anyway that all the tracing programs are not stable with regards to future kernels as kernel internal data structures are subject to change from release to release. Back at last netconf we discussed [0] and agreed to remove this check from bpf_prog_load() and instead document it here in the uapi header that there is no such guarantee for stable API for these programs. [0] http://vger.kernel.org/netconf2018_files/DanielBorkmann_netconf2018.pdf Signed-off-by: Daniel Borkmann Acked-by: Alexei Starovoitov Acked-by: Quentin Monnet Signed-off-by: Alexei Starovoitov --- kernel/bpf/syscall.c | 5 ----- 1 file changed, 5 deletions(-) (limited to 'kernel') diff --git a/kernel/bpf/syscall.c b/kernel/bpf/syscall.c index 6ae062f1cf20..5db31067d85e 100644 --- a/kernel/bpf/syscall.c +++ b/kernel/bpf/syscall.c @@ -1473,11 +1473,6 @@ static int bpf_prog_load(union bpf_attr *attr, union bpf_attr __user *uattr) if (attr->insn_cnt == 0 || attr->insn_cnt > BPF_MAXINSNS) return -E2BIG; - - if (type == BPF_PROG_TYPE_KPROBE && - attr->kern_version != LINUX_VERSION_CODE) - return -EINVAL; - if (type != BPF_PROG_TYPE_SOCKET_FILTER && type != BPF_PROG_TYPE_CGROUP_SKB && !capable(CAP_SYS_ADMIN)) -- cgit v1.2.3