seccomp: add fchmodat2 syscall (kernel v6.6, libseccomp v2.5.5)
Add this syscall to match the profile in containerd
containerd: https://github.com/containerd/containerd/commit/a6e52c74fa043a63d7dae4ac6998215f6c1bb6ac
libseccomp: https://github.com/seccomp/libseccomp/commit/53267af3fb56eed93a50b8ef92f41825c97a7813
kernel: https://github.com/torvalds/linux/commit/09da082b07bbae1c11d9560c8502800039aebcea
fs: Add fchmodat2()
On the userspace side fchmodat(3) is implemented as a wrapper
function which implements the POSIX-specified interface. This
interface differs from the underlying kernel system call, which does not
have a flags argument. Most implementations require procfs [1][2].
There doesn't appear to be a good userspace workaround for this issue
but the implementation in the kernel is pretty straight-forward.
The new fchmodat2() syscall allows to pass the AT_SYMLINK_NOFOLLOW flag,
unlike existing fchmodat.
Signed-off-by: Sebastiaan van Stijn <github@gone.nl>
(cherry picked from commit 6f242f1a28a9e658a6dd29a314cd2d1923427579)
Signed-off-by: Sebastiaan van Stijn <github@gone.nl>