mirrors/linux-stable
1
0
Fork 0
mirror of https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git synced 2024-10-01 22:54:01 +00:00
Code Issues Releases Wiki Activity

x86/pkeys: Skip 'init_pkru' debugfs file creation when pkeys not supported

Browse source 
The PKRU hardware is permissive by default: all reads and writes are
allowed.  The in-kernel policy is restrictive by default: deny all
unnecessary access until explicitly requested.

That policy can be modified with a debugfs file: "x86/init_pkru".
This file is created unconditionally, regardless of PKRU support in
the hardware, which is a little silly.

Avoid creating the file when pkeys are not available.  This also
removes the need to check for pkey support at runtime, which would be
required once the new pkey modification infrastructure is put in place
later in this series.

Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Link: https://lkml.kernel.org/r/20210603230810.113FF3F2@viggo.jf.intel.com
This commit is contained in:
Dave Hansen 2021-06-03 16:08:10 -07:00 committed by Borislav Petkov
parent 8124c8a6b3
commit 314a1e1eab
1 changed files with 4 additions and 0 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

4
arch/x86/mm/pkeys.c
View file

@ -192,6 +192,10 @@ static const struct file_operations fops_init_pkru = {
static int __init create_init_pkru_value(void)
{
/* Do not expose the file if pkeys are not supported. */
if (!cpu_feature_enabled(X86_FEATURE_OSPKE))
return 0;
debugfs_create_file("init_pkru", S_IRUSR | S_IWUSR,
arch_debugfs_dir, NULL, &fops_init_pkru);
return 0;