Merge tag 'mips-fixes_5.16_1' of git://git.kernel.org/pub/scm/linux/kernel/git/mips/linux

Pull MIPS fixes from Thomas Bogendoerfer:

 - wire futex_waitv syscall

 - build fixes for lantiq and bcm63xx configs

 - yamon-dt bugfix

* tag 'mips-fixes_5.16_1' of git://git.kernel.org/pub/scm/linux/kernel/git/mips/linux:
  mips: lantiq: add support for clk_get_parent()
  mips: bcm63xx: add support for clk_get_parent()
  MIPS: generic/yamon-dt: fix uninitialized variable error
  MIPS: syscalls: Wire up futex_waitv syscall
diff --git a/arch/x86/hyperv/hv_init.c b/arch/x86/hyperv/hv_init.c
index 24f4a06..96eb7db 100644
--- a/arch/x86/hyperv/hv_init.c
+++ b/arch/x86/hyperv/hv_init.c
@@ -177,6 +177,9 @@
 		return;
 	}
 
+	if (!hv_vp_index)
+		return;
+
 	hv_reenlightenment_cb = cb;
 
 	/* Make sure callback is registered before we write to MSRs */
@@ -383,20 +386,13 @@
  */
 void __init hyperv_init(void)
 {
-	u64 guest_id, required_msrs;
+	u64 guest_id;
 	union hv_x64_msr_hypercall_contents hypercall_msr;
 	int cpuhp;
 
 	if (x86_hyper_type != X86_HYPER_MS_HYPERV)
 		return;
 
-	/* Absolutely required MSRs */
-	required_msrs = HV_MSR_HYPERCALL_AVAILABLE |
-		HV_MSR_VP_INDEX_AVAILABLE;
-
-	if ((ms_hyperv.features & required_msrs) != required_msrs)
-		return;
-
 	if (hv_common_init())
 		return;
 
diff --git a/arch/x86/kernel/cpu/mshyperv.c b/arch/x86/kernel/cpu/mshyperv.c
index 4794b71..ff55df6 100644
--- a/arch/x86/kernel/cpu/mshyperv.c
+++ b/arch/x86/kernel/cpu/mshyperv.c
@@ -163,12 +163,22 @@
 	cpuid(HYPERV_CPUID_VENDOR_AND_MAX_FUNCTIONS,
 	      &eax, &hyp_signature[0], &hyp_signature[1], &hyp_signature[2]);
 
-	if (eax >= HYPERV_CPUID_MIN &&
-	    eax <= HYPERV_CPUID_MAX &&
-	    !memcmp("Microsoft Hv", hyp_signature, 12))
-		return HYPERV_CPUID_VENDOR_AND_MAX_FUNCTIONS;
+	if (eax < HYPERV_CPUID_MIN || eax > HYPERV_CPUID_MAX ||
+	    memcmp("Microsoft Hv", hyp_signature, 12))
+		return 0;
 
-	return 0;
+	/* HYPERCALL and VP_INDEX MSRs are mandatory for all features. */
+	eax = cpuid_eax(HYPERV_CPUID_FEATURES);
+	if (!(eax & HV_MSR_HYPERCALL_AVAILABLE)) {
+		pr_warn("x86/hyperv: HYPERCALL MSR not available.\n");
+		return 0;
+	}
+	if (!(eax & HV_MSR_VP_INDEX_AVAILABLE)) {
+		pr_warn("x86/hyperv: VP_INDEX MSR not available.\n");
+		return 0;
+	}
+
+	return HYPERV_CPUID_VENDOR_AND_MAX_FUNCTIONS;
 }
 
 static unsigned char hv_get_nmi_reason(void)
diff --git a/drivers/hv/hv_balloon.c b/drivers/hv/hv_balloon.c
index 7f11ea0..ca873a3 100644
--- a/drivers/hv/hv_balloon.c
+++ b/drivers/hv/hv_balloon.c
@@ -480,7 +480,7 @@
 MODULE_PARM_DESC(pressure_report_delay, "Delay in secs in reporting pressure");
 static atomic_t trans_id = ATOMIC_INIT(0);
 
-static int dm_ring_size = 20 * 1024;
+static int dm_ring_size = VMBUS_RING_SIZE(16 * 1024);
 
 /*
  * Driver specific state.
diff --git a/fs/nfsd/nfs4xdr.c b/fs/nfsd/nfs4xdr.c
index b2a1d96..5a93a5d 100644
--- a/fs/nfsd/nfs4xdr.c
+++ b/fs/nfsd/nfs4xdr.c
@@ -288,11 +288,8 @@
 	p = xdr_inline_decode(argp->xdr, count << 2);
 	if (!p)
 		return nfserr_bad_xdr;
-	i = 0;
-	while (i < count)
-		bmval[i++] = be32_to_cpup(p++);
-	while (i < bmlen)
-		bmval[i++] = 0;
+	for (i = 0; i < bmlen; i++)
+		bmval[i] = (i < count) ? be32_to_cpup(p++) : 0;
 
 	return nfs_ok;
 }
diff --git a/include/linux/trace_events.h b/include/linux/trace_events.h
index 50453b2..2d167ac 100644
--- a/include/linux/trace_events.h
+++ b/include/linux/trace_events.h
@@ -673,7 +673,7 @@
 
 #define PERF_MAX_TRACE_SIZE	8192
 
-#define MAX_FILTER_STR_VAL	256	/* Should handle KSYM_SYMBOL_LEN */
+#define MAX_FILTER_STR_VAL	256U	/* Should handle KSYM_SYMBOL_LEN */
 
 enum event_trigger_type {
 	ETT_NONE		= (0),
diff --git a/init/Kconfig b/init/Kconfig
index 036b750..4b7bac1 100644
--- a/init/Kconfig
+++ b/init/Kconfig
@@ -887,7 +887,7 @@
 
 config CC_IMPLICIT_FALLTHROUGH
 	string
-	default "-Wimplicit-fallthrough=5" if CC_IS_GCC
+	default "-Wimplicit-fallthrough=5" if CC_IS_GCC && $(cc-option,-Wimplicit-fallthrough=5)
 	default "-Wimplicit-fallthrough" if CC_IS_CLANG && $(cc-option,-Wunreachable-code-fallthrough)
 
 #
diff --git a/kernel/trace/trace_events_hist.c b/kernel/trace/trace_events_hist.c
index 8a10046..5ea2c9e 100644
--- a/kernel/trace/trace_events_hist.c
+++ b/kernel/trace/trace_events_hist.c
@@ -3026,8 +3026,10 @@
 		if (val->flags & HIST_FIELD_FL_STRING) {
 			char *str = elt_data->field_var_str[j++];
 			char *val_str = (char *)(uintptr_t)var_val;
+			unsigned int size;
 
-			strscpy(str, val_str, val->size);
+			size = min(val->size, STR_VAR_LEN_MAX);
+			strscpy(str, val_str, size);
 			var_val = (u64)(uintptr_t)str;
 		}
 		tracing_map_set_var(elt, var_idx, var_val);
@@ -4914,6 +4916,7 @@
 			if (hist_field->flags & HIST_FIELD_FL_STRING) {
 				unsigned int str_start, var_str_idx, idx;
 				char *str, *val_str;
+				unsigned int size;
 
 				str_start = hist_data->n_field_var_str +
 					hist_data->n_save_var_str;
@@ -4922,7 +4925,9 @@
 
 				str = elt_data->field_var_str[idx];
 				val_str = (char *)(uintptr_t)hist_val;
-				strscpy(str, val_str, hist_field->size);
+
+				size = min(hist_field->size, STR_VAR_LEN_MAX);
+				strscpy(str, val_str, size);
 
 				hist_val = (u64)(uintptr_t)str;
 			}