openkylin
/
linux
mirror of https://gitee.com/openkylin/linux.git
9
0
Fork 0
Code Issues Projects Releases Wiki Activity

Revert "debugfs: inode: debugfs_create_dir uses mode permission from parent" 

This reverts commit 95cde3c599.

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>
This commit is contained in:
Linus Torvalds 2018-06-12 20:52:16 -07:00
parent dbee3d0245
commit f5b7769eb0
1 changed files with 1 additions and 3 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

4
fs/debugfs/inode.c
View File

@ -512,9 +512,7 @@ struct dentry *debugfs_create_dir(const char *name, struct dentry *parent)
if (unlikely(!inode)) if (unlikely(!inode))
return failed_creating(dentry); return failed_creating(dentry);
if (!parent) inode->i_mode = S_IFDIR | S_IRWXU | S_IRUGO | S_IXUGO;
parent = debugfs_mount->mnt_root;
inode->i_mode = S_IFDIR | ((d_inode(parent)->i_mode & 0770));
inode->i_op = &simple_dir_inode_operations; inode->i_op = &simple_dir_inode_operations;
inode->i_fop = &simple_dir_operations; inode->i_fop = &simple_dir_operations;