Update Linux to v5.4.2

Change-Id: Idf6911045d9d382da2cfe01b1edff026404ac8fd
diff --git a/arch/s390/kernel/machine_kexec.c b/arch/s390/kernel/machine_kexec.c
index b7020e7..444a191 100644
--- a/arch/s390/kernel/machine_kexec.c
+++ b/arch/s390/kernel/machine_kexec.c
@@ -27,6 +27,7 @@
 #include <asm/cacheflush.h>
 #include <asm/os_info.h>
 #include <asm/set_memory.h>
+#include <asm/stacktrace.h>
 #include <asm/switch_to.h>
 #include <asm/nmi.h>
 
@@ -95,7 +96,7 @@
 	start_kdump(1);
 
 	/* Die if start_kdump returns */
-	disabled_wait((unsigned long) __builtin_return_address(0));
+	disabled_wait();
 }
 
 /*
@@ -140,7 +141,20 @@
 	 */
 	store_status(__do_machine_kdump, image);
 }
-#endif
+
+static unsigned long do_start_kdump(unsigned long addr)
+{
+	struct kimage *image = (struct kimage *) addr;
+	int (*start_kdump)(int) = (void *)image->start;
+	int rc;
+
+	__arch_local_irq_stnsm(0xfb); /* disable DAT */
+	rc = start_kdump(0);
+	__arch_local_irq_stosm(0x04); /* enable DAT */
+	return rc;
+}
+
+#endif /* CONFIG_CRASH_DUMP */
 
 /*
  * Check if kdump checksums are valid: We call purgatory with parameter "0"
@@ -148,12 +162,9 @@
 static bool kdump_csum_valid(struct kimage *image)
 {
 #ifdef CONFIG_CRASH_DUMP
-	int (*start_kdump)(int) = (void *)image->start;
 	int rc;
 
-	__arch_local_irq_stnsm(0xfb); /* disable DAT */
-	rc = start_kdump(0);
-	__arch_local_irq_stosm(0x04); /* enable DAT */
+	rc = CALL_ON_STACK(do_start_kdump, S390_lowcore.nodat_stack, 1, image);
 	return rc == 0;
 #else
 	return false;
@@ -244,6 +255,9 @@
 	VMCOREINFO_SYMBOL(high_memory);
 	VMCOREINFO_LENGTH(lowcore_ptr, NR_CPUS);
 	mem_assign_absolute(S390_lowcore.vmcore_info, paddr_vmcoreinfo_note());
+	vmcoreinfo_append_str("SDMA=%lx\n", __sdma);
+	vmcoreinfo_append_str("EDMA=%lx\n", __edma);
+	vmcoreinfo_append_str("KERNELOFFSET=%lx\n", kaslr_offset());
 }
 
 void machine_shutdown(void)
@@ -271,7 +285,7 @@
 	(*data_mover)(&image->head, image->start);
 
 	/* Die if kexec returns */
-	disabled_wait((unsigned long) __builtin_return_address(0));
+	disabled_wait();
 }
 
 /*