s390 updates for 5.18-rc6

- Disable -Warray-bounds warning for gcc12, since there known way to
   workaround false positive warnings on lowcore accesses would result
   in worse code on fast paths.
 
 - Avoid lockdep_assert_held() warning in kvm vm memop code.
 
 - Reduce overhead within gmap_rmap code to get rid of long latencies
   when e.g. shutting down 2nd level guests.
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Merge tag 's390-5.18-4' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux

Pull s390 fixes from Heiko Carstens:

 - Disable -Warray-bounds warning for gcc12, since the only known way to
   workaround false positive warnings on lowcore accesses would result
   in worse code on fast paths.

 - Avoid lockdep_assert_held() warning in kvm vm memop code.

 - Reduce overhead within gmap_rmap code to get rid of long latencies
   when e.g. shutting down 2nd level guests.

* tag 's390-5.18-4' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux:
  KVM: s390: vsie/gmap: reduce gmap_rmap overhead
  KVM: s390: Fix lockdep issue in vm memop
  s390: disable -Warray-bounds

arch/s390/Makefile

@@ -30,6 +30,16 @@ KBUILD_CFLAGS_DECOMPRESSOR += -fno-stack-protector
 KBUILD_CFLAGS_DECOMPRESSOR += $(call cc-disable-warning, address-of-packed-member)
 KBUILD_CFLAGS_DECOMPRESSOR += $(if $(CONFIG_DEBUG_INFO),-g)
 KBUILD_CFLAGS_DECOMPRESSOR += $(if $(CONFIG_DEBUG_INFO_DWARF4), $(call cc-option, -gdwarf-4,))
+
+ifdef CONFIG_CC_IS_GCC
+	ifeq ($(call cc-ifversion, -ge, 1200, y), y)
+		ifeq ($(call cc-ifversion, -lt, 1300, y), y)
+			KBUILD_CFLAGS += $(call cc-disable-warning, array-bounds)
+			KBUILD_CFLAGS_DECOMPRESSOR += $(call cc-disable-warning, array-bounds)
+		endif
+	endif
+endif
+
 UTS_MACHINE	:= s390x
 STACK_SIZE	:= $(if $(CONFIG_KASAN),65536,16384)
 CHECKFLAGS	+= -D__s390__ -D__s390x__

arch/s390/kvm/kvm-s390.c

@@ -2384,7 +2384,16 @@ static int kvm_s390_vm_mem_op(struct kvm *kvm, struct kvm_s390_mem_op *mop)
 		return -EINVAL;
 	if (mop->size > MEM_OP_MAX_SIZE)
 		return -E2BIG;
-	if (kvm_s390_pv_is_protected(kvm))
+	/*
+	 * This is technically a heuristic only, if the kvm->lock is not
+	 * taken, it is not guaranteed that the vm is/remains non-protected.
+	 * This is ok from a kernel perspective, wrongdoing is detected
+	 * on the access, -EFAULT is returned and the vm may crash the
+	 * next time it accesses the memory in question.
+	 * There is no sane usecase to do switching and a memop on two
+	 * different CPUs at the same time.
+	 */
+	if (kvm_s390_pv_get_handle(kvm))
 		return -EINVAL;
 	if (mop->flags & KVM_S390_MEMOP_F_SKEY_PROTECTION) {
 		if (access_key_invalid(mop->key))

arch/s390/mm/gmap.c

@@ -1183,6 +1183,7 @@ EXPORT_SYMBOL_GPL(gmap_read_table);
 static inline void gmap_insert_rmap(struct gmap *sg, unsigned long vmaddr,
 				    struct gmap_rmap *rmap)
 {
+	struct gmap_rmap *temp;
 	void __rcu **slot;
 
 	BUG_ON(!gmap_is_shadow(sg));
@@ -1190,6 +1191,12 @@ static inline void gmap_insert_rmap(struct gmap *sg, unsigned long vmaddr,
 	if (slot) {
 		rmap->next = radix_tree_deref_slot_protected(slot,
 							&sg->guest_table_lock);
+		for (temp = rmap->next; temp; temp = temp->next) {
+			if (temp->raddr == rmap->raddr) {
+				kfree(rmap);
+				return;
+			}
+		}
 		radix_tree_replace_slot(&sg->host_to_rmap, slot, rmap);
 	} else {
 		rmap->next = NULL;