From: Alexei Starovoitov <a...@kernel.org> 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... :-)
