Merge tag 's390-6.17-3' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linuxHEADmaster

Pull s390 fixes from Alexander Gordeev:

 - When kernel lockdown is active userspace tools that rely on read
   operations only are unnecessarily blocked. Fix that by avoiding ioctl
   registration during lockdown

 - Invalid NULL pointer accesses succeed due to the lowcore is always
   mapped the identity mapping pinned to zero. To fix that never map the
   first two pages of physical memory with identity mapping

 - Fix invalid SCCB present check in the SCLP interrupt handler

 - Update defconfigs

* tag 's390-6.17-3' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux:
  s390/hypfs: Enable limited access during lockdown
  s390/hypfs: Avoid unnecessary ioctl registration in debugfs
  s390/mm: Do not map lowcore with identity mapping
  s390/sclp: Fix SCCB present check
  s390/configs: Set HZ=1000
  s390/configs: Update defconfigs

1 files changed, 12 insertions, 7 deletions

diff --git a/arch/s390/hypfs/hypfs_dbfs.c b/arch/s390/hypfs/hypfs_dbfs.c
index 5d9effb0867c..41a0d2066fa0 100644
--- a/arch/s390/hypfs/hypfs_dbfs.c
+++ b/arch/s390/hypfs/hypfs_dbfs.c
@@ -6,6 +6,7 @@
  * Author(s): Michael Holzheu <holzheu@linux.vnet.ibm.com>
  */
 
+#include <linux/security.h>
 #include <linux/slab.h>
 #include "hypfs.h"
 
@@ -66,23 +67,27 @@ static long dbfs_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
 	long rc;
 
 	mutex_lock(&df->lock);
-	if (df->unlocked_ioctl)
-		rc = df->unlocked_ioctl(file, cmd, arg);
-	else
-		rc = -ENOTTY;
+	rc = df->unlocked_ioctl(file, cmd, arg);
 	mutex_unlock(&df->lock);
 	return rc;
 }
 
-static const struct file_operations dbfs_ops = {
+static const struct file_operations dbfs_ops_ioctl = {
 	.read		= dbfs_read,
 	.unlocked_ioctl = dbfs_ioctl,
 };
 
+static const struct file_operations dbfs_ops = {
+	.read		= dbfs_read,
+};
+
 void hypfs_dbfs_create_file(struct hypfs_dbfs_file *df)
 {
-	df->dentry = debugfs_create_file(df->name, 0400, dbfs_dir, df,
-					 &dbfs_ops);
+	const struct file_operations *fops = &dbfs_ops;
+
+	if (df->unlocked_ioctl && !security_locked_down(LOCKDOWN_DEBUGFS))
+		fops = &dbfs_ops_ioctl;
+	df->dentry = debugfs_create_file(df->name, 0400, dbfs_dir, df, fops);
 	mutex_init(&df->lock);
 }