> On Sep 4, 2019, at 8:15 PM, Alexei Starovoitov <alexei.starovoitov@xxxxxxxxx> wrote: > > On Thu, Sep 05, 2019 at 02:51:51AM +0000, Song Liu wrote: >> >> >>> On Sep 4, 2019, at 6:32 PM, Alexei Starovoitov <alexei.starovoitov@xxxxxxxxx> wrote: >>> >>> On Thu, Sep 05, 2019 at 12:34:36AM +0000, Song Liu wrote: >>>> >>>> >>>>> On Sep 4, 2019, at 11:43 AM, Alexei Starovoitov <ast@xxxxxxxxxx> wrote: >>>>> >>>>> Implement permissions as stated in uapi/linux/capability.h >>>>> >>>>> Signed-off-by: Alexei Starovoitov <ast@xxxxxxxxxx> >>>>> >>>> >>>> [...] >>>> >>>>> @@ -1648,11 +1648,11 @@ static int bpf_prog_load(union bpf_attr *attr, union bpf_attr __user *uattr) >>>>> is_gpl = license_is_gpl_compatible(license); >>>>> >>>>> if (attr->insn_cnt == 0 || >>>>> - attr->insn_cnt > (capable(CAP_SYS_ADMIN) ? BPF_COMPLEXITY_LIMIT_INSNS : BPF_MAXINSNS)) >>>>> + attr->insn_cnt > (capable_bpf() ? BPF_COMPLEXITY_LIMIT_INSNS : BPF_MAXINSNS)) >>>>> return -E2BIG; >>>>> if (type != BPF_PROG_TYPE_SOCKET_FILTER && >>>>> type != BPF_PROG_TYPE_CGROUP_SKB && >>>>> - !capable(CAP_SYS_ADMIN)) >>>>> + !capable_bpf()) >>>>> return -EPERM; >>>> >>>> Do we allow load BPF_PROG_TYPE_SOCKET_FILTER and BPF_PROG_TYPE_CGROUP_SKB >>>> without CAP_BPF? If so, maybe highlight in the header? >>> >>> of course. there is no change in behavior. >>> 'highlight in the header'? >>> you mean in commit log? >>> I think it's a bit weird to describe things in commit that patch >>> is _not_ changing vs things that patch does actually change. >>> This type of comment would be great in a doc though. >>> The doc will be coming separately in the follow up assuming >>> the whole thing lands. I'll remember to note that bit. >> >> I meant capability.h: >> >> + * CAP_BPF allows the following BPF operations: >> + * - Loading all types of BPF programs >> >> But CAP_BPF is not required to load all types of programs. > > yes, but above statement is still correct, right? > > And right below it says: > * CAP_BPF allows the following BPF operations: > * - Loading all types of BPF programs > * - Creating all types of BPF maps except: > * - stackmap that needs CAP_TRACING > * - devmap that needs CAP_NET_ADMIN > * - cpumap that needs CAP_SYS_ADMIN > which is also correct, but CAP_BPF is not required > for array, hash, prog_array, percpu, map-in-map ... > except their lru variants... > and except if they contain bpf_spin_lock... > and if they need BTF it currently can be loaded with cap_sys_admin only... > > If we say something about socket_filter, cg_skb progs in capability.h > we should clarify maps as well, but then it will become too big for .h > The comments in capability.h already look too long to me. > All that info and a lot more belongs in the doc. Agreed. We cannot put all these details in capability.h. Doc/wikipages would be better fit for these information. Thanks, Song
