On Tue, Jul 16, 2019 at 06:27:17PM -0700, Palmer Dabbelt wrote: > man 3p says that fchmodat() takes a flags argument, but the Linux > syscall does not. There doesn't appear to be a good userspace > workaround for this issue but the implementation in the kernel is pretty > straight-forward. The specific use case where the missing flags came up > was WRT a fuse filesystem implemenation, but the functionality is pretty > generic so I'm assuming there would be other use cases. Note that we do have a workaround in musl libc with O_PATH and /proc/self/fd, but a syscall that allows a proper fix with the ugly workaround only in the fallback path for old kernels will be much appreciated! What about also doing a new SYS_faccessat4 with working AT_EACCESS flag? The workaround we have to do for it is far worse. Rich
