bpf: Re-support uid and gid when mounting bpffs

For a clean, conflict-free revert of the token-related patches in commit
d17aff807f84 ("Revert BPF token-related functionality"), the bpf fs commit
750e785796bb ("bpf: Support uid and gid when mounting bpffs") was undone
temporarily as well.

This patch manually re-adds the functionality from the original one back
in 750e785796bb, no other functional changes intended.

Testing:

  # mount -t bpf -o uid=65534,gid=65534 bpffs ./foo
  # ls -la . | grep foo
  drwxrwxrwt   2 nobody nogroup          0 Dec 20 13:16 foo
  # mount -t bpf
  bpffs on /root/foo type bpf (rw,relatime,uid=65534,gid=65534)

Also, passing invalid arguments for uid/gid are properly rejected as expected.

Fixes: d17aff807f84 ("Revert BPF token-related functionality")
Signed-off-by: Daniel Borkmann <[email protected]>
Reviewed-by: Christian Brauner <[email protected]>
Cc: Jie Jiang <[email protected]>
Cc: Andrii Nakryiko <[email protected]>
Cc: [email protected]
Link: https://lore.kernel.org/bpf/[email protected]

0 files changed, 0 insertions, 0 deletions