Merge 5.2-rc4 into char-misc-next

We want the char/misc driver fixes in here as well.

Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

4 files changed, 28 insertions, 28 deletions

diff --git a/drivers/misc/lkdtm/bugs.c b/drivers/misc/lkdtm/bugs.c
index 7eebbdfbcacd..17f839dee976 100644
--- a/drivers/misc/lkdtm/bugs.c
+++ b/drivers/misc/lkdtm/bugs.c
@@ -32,12 +32,20 @@ static int recur_count = REC_NUM_DEFAULT;
 
 static DEFINE_SPINLOCK(lock_me_up);
 
-static int recursive_loop(int remaining)
+/*
+ * Make sure compiler does not optimize this function or stack frame away:
+ * - function marked noinline
+ * - stack variables are marked volatile
+ * - stack variables are written (memset()) and read (pr_info())
+ * - function has external effects (pr_info())
+ * */
+static int noinline recursive_loop(int remaining)
 {
-	char buf[REC_STACK_SIZE];
+	volatile char buf[REC_STACK_SIZE];
 
-	/* Make sure compiler does not optimize this away. */
-	memset(buf, (remaining & 0xff) | 0x1, REC_STACK_SIZE);
+	memset((void *)buf, remaining & 0xFF, sizeof(buf));
+	pr_info("loop %d/%d ...\n", (int)buf[remaining % sizeof(buf)],
+		recur_count);
 	if (!remaining)
 		return 0;
 	else
@@ -81,9 +89,12 @@ void lkdtm_LOOP(void)
 		;
 }
 
-void lkdtm_OVERFLOW(void)
+void lkdtm_EXHAUST_STACK(void)
 {
-	(void) recursive_loop(recur_count);
+	pr_info("Calling function with %d frame size to depth %d ...\n",
+		REC_STACK_SIZE, recur_count);
+	recursive_loop(recur_count);
+	pr_info("FAIL: survived without exhausting stack?!\n");
 }
 
 static noinline void __lkdtm_CORRUPT_STACK(void *stack)
diff --git a/drivers/misc/lkdtm/core.c b/drivers/misc/lkdtm/core.c
index b51cf182b031..8a1428d4f138 100644
--- a/drivers/misc/lkdtm/core.c
+++ b/drivers/misc/lkdtm/core.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
 /*
  * Linux Kernel Dump Test Module for testing kernel crashes conditions:
  * induces system failures at predefined crashpoints and under predefined
@@ -5,20 +6,6 @@
  * sanity checking and crash dumps obtained using different dumping
  * solutions.
  *
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation; either version 2 of the License, or
- * (at your option) any later version.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program; if not, write to the Free Software
- * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
- *
  * Copyright (C) IBM Corporation, 2006
  *
  * Author: Ankita Garg <ankita@in.ibm.com>
@@ -119,12 +106,12 @@ static const struct crashtype crashtypes[] = {
 	CRASHTYPE(WARNING),
 	CRASHTYPE(EXCEPTION),
 	CRASHTYPE(LOOP),
-	CRASHTYPE(OVERFLOW),
+	CRASHTYPE(EXHAUST_STACK),
+	CRASHTYPE(CORRUPT_STACK),
+	CRASHTYPE(CORRUPT_STACK_STRONG),
 	CRASHTYPE(CORRUPT_LIST_ADD),
 	CRASHTYPE(CORRUPT_LIST_DEL),
 	CRASHTYPE(CORRUPT_USER_DS),
-	CRASHTYPE(CORRUPT_STACK),
-	CRASHTYPE(CORRUPT_STACK_STRONG),
 	CRASHTYPE(STACK_GUARD_PAGE_LEADING),
 	CRASHTYPE(STACK_GUARD_PAGE_TRAILING),
 	CRASHTYPE(UNALIGNED_LOAD_STORE_WRITE),
diff --git a/drivers/misc/lkdtm/lkdtm.h b/drivers/misc/lkdtm/lkdtm.h
index b69ee004a3f7..23dc565b4307 100644
--- a/drivers/misc/lkdtm/lkdtm.h
+++ b/drivers/misc/lkdtm/lkdtm.h
@@ -13,7 +13,7 @@ void lkdtm_BUG(void);
 void lkdtm_WARNING(void);
 void lkdtm_EXCEPTION(void);
 void lkdtm_LOOP(void);
-void lkdtm_OVERFLOW(void);
+void lkdtm_EXHAUST_STACK(void);
 void lkdtm_CORRUPT_STACK(void);
 void lkdtm_CORRUPT_STACK_STRONG(void);
 void lkdtm_UNALIGNED_LOAD_STORE_WRITE(void);
diff --git a/drivers/misc/lkdtm/usercopy.c b/drivers/misc/lkdtm/usercopy.c
index d5a0e7f1813b..e172719dd86d 100644
--- a/drivers/misc/lkdtm/usercopy.c
+++ b/drivers/misc/lkdtm/usercopy.c
@@ -324,14 +324,16 @@ free_user:
 
 void lkdtm_USERCOPY_KERNEL_DS(void)
 {
-	char __user *user_ptr = (char __user *)ERR_PTR(-EINVAL);
+	char __user *user_ptr =
+		(char __user *)(0xFUL << (sizeof(unsigned long) * 8 - 4));
 	mm_segment_t old_fs = get_fs();
 	char buf[10] = {0};
 
-	pr_info("attempting copy_to_user on unmapped kernel address\n");
+	pr_info("attempting copy_to_user() to noncanonical address: %px\n",
+		user_ptr);
 	set_fs(KERNEL_DS);
-	if (copy_to_user(user_ptr, buf, sizeof(buf)))
-		pr_info("copy_to_user un unmapped kernel address failed\n");
+	if (copy_to_user(user_ptr, buf, sizeof(buf)) == 0)
+		pr_err("copy_to_user() to noncanonical address succeeded!?\n");
 	set_fs(old_fs);
 }