Revert "debugfs: inode: debugfs_create_dir uses mode permission from parent"
authorLinus Torvalds <torvalds@linux-foundation.org>
Wed, 13 Jun 2018 03:52:16 +0000 (20:52 -0700)
committerLinus Torvalds <torvalds@linux-foundation.org>
Wed, 13 Jun 2018 03:52:16 +0000 (20:52 -0700)
commitf5b7769eb0400ec5217a47e41148a9f816ca1f9f
tree2523ae64572026769c2d362a5b7e18fff35d49f7
parentdbee3d02458b129b847c21f5fa60baba3eafc6f7
Revert "debugfs: inode: debugfs_create_dir uses mode permission from parent"

This reverts commit 95cde3c59966f6371b6bcd9e4e2da2ba64ee9775.

The commit had good intentions, but it breaks kvm-tool and qemu-kvm.

With it in place, "lkvm run" just fails with

  Error: KVM_CREATE_VM ioctl
  Warning: Failed init: kvm__init

which isn't a wonderful error message, but bisection pinpointed the
problematic commit.

The problem is almost certainly due to the special kvm debugfs entries
created dynamically by kvm under /sys/kernel/debug/kvm/.  See
kvm_create_vm_debugfs()

Bisected-and-reported-by: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Wanpeng Li <kernellwp@gmail.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Thomas Richter <tmricht@linux.ibm.com>
Cc: Kees Cook <keescook@chromium.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
fs/debugfs/inode.c