On Tue, Dec 10, 2024 at 10:58:52AM -0800, Alexei Starovoitov wrote: > On Tue, Dec 10, 2024 at 6:43 AM Christian Brauner <brauner@xxxxxxxxxx> wrote: > > > > On Tue, Dec 10, 2024 at 02:03:53PM +0000, Juntong Deng wrote: > > > Currently fs kfuncs are only available for LSM program type, but fs > > > kfuncs are generic and useful for scenarios other than LSM. > > > > > > This patch makes fs kfuncs available for SYSCALL and TRACING > > > program types. > > > > I would like a detailed explanation from the maintainers what it means > > to make this available to SYSCALL program types, please. > > Sigh. Hm? Was that directed at my question? I don't have the background to judge this and this whole api looks like a giant footgun so far for questionable purposes. I have a hard time seeing parts of CRIU moved into bpf especially because all of the userspace stuff exists. > This is obviously not safe from tracing progs. > > From BPF_PROG_TYPE_SYSCALL these kfuncs should be safe to use, > since those progs are not attached to anything. > Such progs can only be executed via sys_bpf syscall prog_run command. > They're sleepable, preemptable, faultable, in task ctx. > > But I'm not sure what's the value of enabling these kfuncs for > BPF_PROG_TYPE_SYSCALL.
