On Fri, Jun 27, 2014 at 5:19 PM, Andy Lutomirski <luto@xxxxxxxxxxxxxx> wrote: > On Fri, Jun 27, 2014 at 5:05 PM, Alexei Starovoitov <ast@xxxxxxxxxxxx> wrote: >> eBPF programs are safe run-to-completion functions with load/unload >> methods from userspace similar to kernel modules. >> >> User space API: >> >> - load eBPF program >> prog_id = bpf_prog_load(int prog_id, bpf_prog_type, struct nlattr *prog, int len) >> >> where 'prog' is a sequence of sections (currently TEXT and LICENSE) >> TEXT - array of eBPF instructions >> LICENSE - GPL compatible >> + >> + err = -EINVAL; >> + /* look for mandatory license string */ >> + if (!tb[BPF_PROG_LICENSE]) >> + goto free_attr; >> + >> + /* eBPF programs must be GPL compatible */ >> + if (!license_is_gpl_compatible(nla_data(tb[BPF_PROG_LICENSE]))) >> + goto free_attr; > > Seriously? My mind boggles. Yes. Quite a bit of logic can fit into one eBPF program. I don't think it's wise to leave this door open for abuse. This check makes it clear that if you write a program in C, the source code must be available. If program is written in assembler than this check is nop anyway. btw this patch doesn't include debugfs access to all loaded eBPF programs. Similarly to kernel modules I'm planning to have a way to list all loaded programs with optional assembler dump of instructions. -- To unsubscribe from this list: send the line "unsubscribe linux-api" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
