Re: [PATCH v3 net-next 0/2] bpfilter

[David Miller]

From: Alexei Starovoitov <ast@xxxxxxxxxx>
Date: Mon, 21 May 2018 19:22:28 -0700

> v2->v3:
> - followed Luis's suggestion and significantly simplied first patch
>   with shmem_kernel_file_setup+kernel_write. Added kdoc for new helper
> - fixed typos and race to access pipes with mutex
> - tested with bpfilter being 'builtin'. CONFIG_BPFILTER_UMH=y|m both work.
>   Interesting to see a usermode executable being embedded inside vmlinux.
> - it doesn't hurt to enable bpfilter in .config.
>   ip_setsockopt commands sent to usermode via pipes and -ENOPROTOOPT is
>   returned from userspace, so kernel falls back to original iptables code
> 
> v1->v2:
> this patch set is almost a full rewrite of the earlier umh modules approach
> The v1 of patches and follow up discussion was covered by LWN:
> https://lwn.net/Articles/749108/
> 
> I believe the v2 addresses all issues brought up by Andy and others.
> Mainly there are zero changes to kernel/module.c
> Instead of teaching module loading logic to recognize special
> umh module, let normal kernel modules execute part of its own
> .init.rodata as a new user space process (Andy's idea)
> Patch 1 introduces this new helper:
> int fork_usermode_blob(void *data, size_t len, struct umh_info *info);
> Input:
>   data + len == executable file
> Output:
>   struct umh_info {
>        struct file *pipe_to_umh;
>        struct file *pipe_from_umh;
>        pid_t pid;
>   };

Series applied, let the madness begin... :-)