Merge tag 'v4.19.23' into linux-4.19.y-rt

This is the 4.19.23 stable release

5 files changed, 18 insertions, 9 deletions

diff --git a/arch/s390/include/asm/mmu_context.h b/arch/s390/include/asm/mmu_context.h
index f1ab9420ccfb..09b61d0e491f 100644
--- a/arch/s390/include/asm/mmu_context.h
+++ b/arch/s390/include/asm/mmu_context.h
@@ -89,8 +89,6 @@ static inline void switch_mm(struct mm_struct *prev, struct mm_struct *next,
 {
 	int cpu = smp_processor_id();
 
-	if (prev == next)
-		return;
 	S390_lowcore.user_asce = next->context.asce;
 	cpumask_set_cpu(cpu, &next->context.cpu_attach_mask);
 	/* Clear previous user-ASCE from CR1 and CR7 */
@@ -102,7 +100,8 @@ static inline void switch_mm(struct mm_struct *prev, struct mm_struct *next,
 		__ctl_load(S390_lowcore.vdso_asce, 7, 7);
 		clear_cpu_flag(CIF_ASCE_SECONDARY);
 	}
-	cpumask_clear_cpu(cpu, &prev->context.cpu_attach_mask);
+	if (prev != next)
+		cpumask_clear_cpu(cpu, &prev->context.cpu_attach_mask);
 }
 
 #define finish_arch_post_lock_switch finish_arch_post_lock_switch
diff --git a/arch/s390/include/uapi/asm/zcrypt.h b/arch/s390/include/uapi/asm/zcrypt.h
index 2bb1f3bb98ac..48c784f2101a 100644
--- a/arch/s390/include/uapi/asm/zcrypt.h
+++ b/arch/s390/include/uapi/asm/zcrypt.h
@@ -147,8 +147,8 @@ struct ica_xcRB {
  * @cprb_len:		CPRB header length [0x0020]
  * @cprb_ver_id:	CPRB version id.   [0x04]
  * @pad_000:		Alignment pad bytes
- * @flags:		Admin cmd [0x80] or functional cmd [0x00]
- * @func_id:		Function id / subtype [0x5434]
+ * @flags:		Admin bit [0x80], Special bit [0x20]
+ * @func_id:		Function id / subtype [0x5434] "T4"
  * @source_id:		Source id [originator id]
  * @target_id:		Target id [usage/ctrl domain id]
  * @ret_code:		Return code
diff --git a/arch/s390/kernel/early.c b/arch/s390/kernel/early.c
index 5b28b434f8a1..e7e6608b996c 100644
--- a/arch/s390/kernel/early.c
+++ b/arch/s390/kernel/early.c
@@ -64,10 +64,10 @@ static noinline __init void detect_machine_type(void)
 	if (stsi(vmms, 3, 2, 2) || !vmms->count)
 		return;
 
-	/* Running under KVM? If not we assume z/VM */
+	/* Detect known hypervisors */
 	if (!memcmp(vmms->vm[0].cpi, "\xd2\xe5\xd4", 3))
 		S390_lowcore.machine_flags |= MACHINE_FLAG_KVM;
-	else
+	else if (!memcmp(vmms->vm[0].cpi, "\xa9\x61\xe5\xd4", 4))
 		S390_lowcore.machine_flags |= MACHINE_FLAG_VM;
 }
 
diff --git a/arch/s390/kernel/setup.c b/arch/s390/kernel/setup.c
index c637c12f9e37..a0097f8bada8 100644
--- a/arch/s390/kernel/setup.c
+++ b/arch/s390/kernel/setup.c
@@ -882,6 +882,8 @@ void __init setup_arch(char **cmdline_p)
 		pr_info("Linux is running under KVM in 64-bit mode\n");
 	else if (MACHINE_IS_LPAR)
 		pr_info("Linux is running natively in 64-bit mode\n");
+	else
+		pr_info("Linux is running as a guest in 64-bit mode\n");
 
 	/* Have one command line that is parsed and saved in /proc/cmdline */
 	/* boot_command_line has been already set up in early.c */
diff --git a/arch/s390/kernel/smp.c b/arch/s390/kernel/smp.c
index 2f8f7d7dd9a8..da02f4087d61 100644
--- a/arch/s390/kernel/smp.c
+++ b/arch/s390/kernel/smp.c
@@ -371,9 +371,13 @@ void smp_call_online_cpu(void (*func)(void *), void *data)
  */
 void smp_call_ipl_cpu(void (*func)(void *), void *data)
 {
+	struct lowcore *lc = pcpu_devices->lowcore;
+
+	if (pcpu_devices[0].address == stap())
+		lc = &S390_lowcore;
+
 	pcpu_delegate(&pcpu_devices[0], func, data,
-		      pcpu_devices->lowcore->panic_stack -
-		      PANIC_FRAME_OFFSET + PAGE_SIZE);
+		      lc->panic_stack - PANIC_FRAME_OFFSET + PAGE_SIZE);
 }
 
 int smp_find_processor_id(u16 address)
@@ -1152,7 +1156,11 @@ static ssize_t __ref rescan_store(struct device *dev,
 {
 	int rc;
 
+	rc = lock_device_hotplug_sysfs();
+	if (rc)
+		return rc;
 	rc = smp_rescan_cpus();
+	unlock_device_hotplug();
 	return rc ? rc : count;
 }
 static DEVICE_ATTR_WO(rescan);