1 files changed, 28 insertions, 25 deletions

diff --git a/drivers/misc/lkdtm/bugs.c b/drivers/misc/lkdtm/bugs.c
index 736675f0a246..4dfbfd51bdf7 100644
--- a/drivers/misc/lkdtm/bugs.c
+++ b/drivers/misc/lkdtm/bugs.c
@@ -13,7 +13,7 @@
 #include <linux/uaccess.h>
 #include <linux/slab.h>
 
-#ifdef CONFIG_X86_32
+#if IS_ENABLED(CONFIG_X86_32) && !IS_ENABLED(CONFIG_UML)
 #include <asm/desc.h>
 #endif
 
@@ -118,9 +118,8 @@ noinline void lkdtm_CORRUPT_STACK(void)
 	/* Use default char array length that triggers stack protection. */
 	char data[8] __aligned(sizeof(void *));
 
-	__lkdtm_CORRUPT_STACK(&data);
-
-	pr_info("Corrupted stack containing char array ...\n");
+	pr_info("Corrupting stack containing char array ...\n");
+	__lkdtm_CORRUPT_STACK((void *)&data);
 }
 
 /* Same as above but will only get a canary with -fstack-protector-strong */
@@ -131,9 +130,8 @@ noinline void lkdtm_CORRUPT_STACK_STRONG(void)
 		unsigned long *ptr;
 	} data __aligned(sizeof(void *));
 
-	__lkdtm_CORRUPT_STACK(&data);
-
-	pr_info("Corrupted stack containing union ...\n");
+	pr_info("Corrupting stack containing union ...\n");
+	__lkdtm_CORRUPT_STACK((void *)&data);
 }
 
 void lkdtm_UNALIGNED_LOAD_STORE_WRITE(void)
@@ -248,6 +246,7 @@ void lkdtm_ARRAY_BOUNDS(void)
 
 	kfree(not_checked);
 	kfree(checked);
+	pr_err("FAIL: survived array bounds overflow!\n");
 }
 
 void lkdtm_CORRUPT_LIST_ADD(void)
@@ -334,7 +333,7 @@ void lkdtm_STACK_GUARD_PAGE_LEADING(void)
 
 	byte = *ptr;
 
-	pr_err("FAIL: accessed page before stack!\n");
+	pr_err("FAIL: accessed page before stack! (byte: %x)\n", byte);
 }
 
 /* Test that VMAP_STACK is actually allocating with a trailing guard page */
@@ -348,7 +347,7 @@ void lkdtm_STACK_GUARD_PAGE_TRAILING(void)
 
 	byte = *ptr;
 
-	pr_err("FAIL: accessed page after stack!\n");
+	pr_err("FAIL: accessed page after stack! (byte: %x)\n", byte);
 }
 
 void lkdtm_UNSET_SMEP(void)
@@ -419,7 +418,7 @@ void lkdtm_UNSET_SMEP(void)
 
 void lkdtm_DOUBLE_FAULT(void)
 {
-#ifdef CONFIG_X86_32
+#if IS_ENABLED(CONFIG_X86_32) && !IS_ENABLED(CONFIG_UML)
 	/*
 	 * Trigger #DF by setting the stack limit to zero.  This clobbers
 	 * a GDT TLS slot, which is okay because the current task will die
@@ -454,38 +453,42 @@ void lkdtm_DOUBLE_FAULT(void)
 #endif
 }
 
-#ifdef CONFIG_ARM64_PTR_AUTH
+#ifdef CONFIG_ARM64
 static noinline void change_pac_parameters(void)
 {
-	/* Reset the keys of current task */
-	ptrauth_thread_init_kernel(current);
-	ptrauth_thread_switch_kernel(current);
+	if (IS_ENABLED(CONFIG_ARM64_PTR_AUTH)) {
+		/* Reset the keys of current task */
+		ptrauth_thread_init_kernel(current);
+		ptrauth_thread_switch_kernel(current);
+	}
 }
+#endif
 
-#define CORRUPT_PAC_ITERATE	10
 noinline void lkdtm_CORRUPT_PAC(void)
 {
+#ifdef CONFIG_ARM64
+#define CORRUPT_PAC_ITERATE	10
 	int i;
 
+	if (!IS_ENABLED(CONFIG_ARM64_PTR_AUTH))
+		pr_err("FAIL: kernel not built with CONFIG_ARM64_PTR_AUTH\n");
+
 	if (!system_supports_address_auth()) {
-		pr_err("FAIL: arm64 pointer authentication feature not present\n");
+		pr_err("FAIL: CPU lacks pointer authentication feature\n");
 		return;
 	}
 
-	pr_info("Change the PAC parameters to force function return failure\n");
+	pr_info("changing PAC parameters to force function return failure...\n");
 	/*
-	 * Pac is a hash value computed from input keys, return address and
+	 * PAC is a hash value computed from input keys, return address and
 	 * stack pointer. As pac has fewer bits so there is a chance of
 	 * collision, so iterate few times to reduce the collision probability.
 	 */
 	for (i = 0; i < CORRUPT_PAC_ITERATE; i++)
 		change_pac_parameters();
 
-	pr_err("FAIL: %s test failed. Kernel may be unstable from here\n", __func__);
-}
-#else /* !CONFIG_ARM64_PTR_AUTH */
-noinline void lkdtm_CORRUPT_PAC(void)
-{
-	pr_err("FAIL: arm64 pointer authentication config disabled\n");
-}
+	pr_err("FAIL: survived PAC changes! Kernel may be unstable from here\n");
+#else
+	pr_err("XFAIL: this test is arm64-only\n");
 #endif
+}