On 21-Feb 11:19, Casey Schaufler wrote: > On 2/20/2020 9:52 AM, KP Singh wrote: > > From: KP Singh <kpsingh@xxxxxxxxxx> > > Again, apologies for the CC list trimming. > > > > > # v3 -> v4 > > > > https://lkml.org/lkml/2020/1/23/515 > > > > * Moved away from allocating a separate security_hook_heads and adding a > > new special case for arch_prepare_bpf_trampoline to using BPF fexit > > trampolines called from the right place in the LSM hook and toggled by > > static keys based on the discussion in: > > > > https://lore.kernel.org/bpf/CAG48ez25mW+_oCxgCtbiGMX07g_ph79UOJa07h=o_6B6+Q-u5g@xxxxxxxxxxxxxx/ > > > > * Since the code does not deal with security_hook_heads anymore, it goes > > from "being a BPF LSM" to "BPF program attachment to LSM hooks". > > I've finally been able to review the entire patch set. > I can't imagine how it can make sense to add this much > complexity to the LSM infrastructure in support of this > feature. There is macro magic going on that is going to > break, and soon. You are introducing dependencies on BPF > into the infrastructure, and that's unnecessary and most > likely harmful. We will be happy to document each of the macros in detail. Do note a few things here: * There is really nothing magical about them though, the LSM hooks are collectively declared in lsm_hook_names.h and are used to delcare the security_list_options and security_hook_heads for the LSM framework (this was previously maitained in two different places): For BPF, they declare: * bpf_lsm_<name> attachment points and their prototypes. * A static key (bpf_lsm_key_<name>) to enable and disable these hooks with a function to set its value i.e. (bpf_lsm_<name>_set_enabled). * We have kept the BPF related macros out of security/. * All the BPF calls in the LSM infrastructure are guarded by CONFIG_BPF_LSM (there are only two main calls though, i.e. call_int_hook, call_void_hook). Honestly, the macros aren't any more complicated than call_int_progs/call_void_progs. - KP > > Would you please drop the excessive optimization? I understand > that there's been a lot of discussion and debate about it, > but this implementation is out of control, disruptive, and > dangerous to the code around it. > >
