1 files changed, 11 insertions, 12 deletions

diff --git a/arch/s390/kernel/machine_kexec.c b/arch/s390/kernel/machine_kexec.c
index 3d0b14afa232..a80050bbe2e4 100644
--- a/arch/s390/kernel/machine_kexec.c
+++ b/arch/s390/kernel/machine_kexec.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0
 /*
  * Copyright IBM Corp. 2005, 2011
  *
@@ -105,7 +106,7 @@ static void __do_machine_kdump(void *image)
 static noinline void __machine_kdump(void *image)
 {
 	struct mcesa *mcesa;
-	unsigned long cr2_old, cr2_new;
+	union ctlreg2 cr2_old, cr2_new;
 	int this_cpu, cpu;
 
 	lgr_info_log();
@@ -122,11 +123,12 @@ static noinline void __machine_kdump(void *image)
 	if (MACHINE_HAS_VX)
 		save_vx_regs((__vector128 *) mcesa->vector_save_area);
 	if (MACHINE_HAS_GS) {
-		__ctl_store(cr2_old, 2, 2);
-		cr2_new = cr2_old | (1UL << 4);
-		__ctl_load(cr2_new, 2, 2);
+		__ctl_store(cr2_old.val, 2, 2);
+		cr2_new = cr2_old;
+		cr2_new.gse = 1;
+		__ctl_load(cr2_new.val, 2, 2);
 		save_gs_cb((struct gs_cb *) mcesa->guarded_storage_save_area);
-		__ctl_load(cr2_old, 2, 2);
+		__ctl_load(cr2_old.val, 2, 2);
 	}
 	/*
 	 * To create a good backchain for this CPU in the dump store_status
@@ -144,7 +146,7 @@ static noinline void __machine_kdump(void *image)
 /*
  * Check if kdump checksums are valid: We call purgatory with parameter "0"
  */
-static int kdump_csum_valid(struct kimage *image)
+static bool kdump_csum_valid(struct kimage *image)
 {
 #ifdef CONFIG_CRASH_DUMP
 	int (*start_kdump)(int) = (void *)image->start;
@@ -153,9 +155,9 @@ static int kdump_csum_valid(struct kimage *image)
 	__arch_local_irq_stnsm(0xfb); /* disable DAT */
 	rc = start_kdump(0);
 	__arch_local_irq_stosm(0x04); /* enable DAT */
-	return rc ? 0 : -EINVAL;
+	return rc == 0;
 #else
-	return -EINVAL;
+	return false;
 #endif
 }
 
@@ -218,10 +220,6 @@ int machine_kexec_prepare(struct kimage *image)
 {
 	void *reboot_code_buffer;
 
-	/* Can't replace kernel image since it is read-only. */
-	if (ipl_flags & IPL_NSS_VALID)
-		return -EOPNOTSUPP;
-
 	if (image->type == KEXEC_TYPE_CRASH)
 		return machine_kexec_prepare_kdump();
 
@@ -268,6 +266,7 @@ static void __do_machine_kexec(void *data)
 	s390_reset_system();
 	data_mover = (relocate_kernel_t) page_to_phys(image->control_code_page);
 
+	__arch_local_irq_stnsm(0xfb); /* disable DAT - avoid no-execute */
 	/* Call the moving routine */
 	(*data_mover)(&image->head, image->start);