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authorLinus Torvalds <torvalds@linux-foundation.org>2018-04-27 10:39:38 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2018-04-27 10:39:38 -0700
commitd8a332730e757129e70675679f2b2a03f1ecf65e (patch)
tree90f955d200bd6837eea81f14dad543ba5140fdd0
parentee3748be5c18db11f17baebf50405bbebeb85471 (diff)
parent6a7228d90d42bcacfe38786756ba62762b91c20a (diff)
downloadlinux-d8a332730e757129e70675679f2b2a03f1ecf65e.tar.gz
Merge tag 'char-misc-4.17-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc
Pull char/misc driver fixes from Greg KH:
 "Here are some small char and misc driver fixes for 4.17-rc3

  A variety of small things that have fallen out after 4.17-rc1 was out.
  Some vboxguest fixes for systems with lots of memory, amba bus fixes,
  some MAINTAINERS updates, uio_hv_generic driver fixes, and a few other
  minor things that resolve problems that people reported.

  The amba bus fixes took twice to get right, the first time I messed up
  applying the patches in the wrong order, hence the revert and later
  addition again with the correct fix, sorry about that.

  All of these have been in linux-next with no reported issues"

* tag 'char-misc-4.17-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc:
  ARM: amba: Fix race condition with driver_override
  ARM: amba: Make driver_override output consistent with other buses
  Revert "ARM: amba: Fix race condition with driver_override"
  ARM: amba: Don't read past the end of sysfs "driver_override" buffer
  ARM: amba: Fix race condition with driver_override
  virt: vbox: Log an error when we fail to get the host version
  virt: vbox: Use __get_free_pages instead of kmalloc for DMA32 memory
  virt: vbox: Add vbg_req_free() helper function
  virt: vbox: Move declarations of vboxguest private functions to private header
  slimbus: Fix out-of-bounds access in slim_slicesize()
  MAINTAINERS: add dri-devel&linaro-mm for Android ION
  fpga-manager: altera-ps-spi: preserve nCONFIG state
  MAINTAINERS: update my email address
  uio_hv_generic: fix subchannel ring mmap
  uio_hv_generic: use correct channel in isr
  uio_hv_generic: make ring buffer attribute for primary channel
  uio_hv_generic: set size of ring buffer attribute
  ANDROID: binder: prevent transactions into own process.
-rw-r--r--MAINTAINERS6
-rw-r--r--drivers/amba/bus.c17
-rw-r--r--drivers/android/binder.c8
-rw-r--r--drivers/fpga/altera-ps-spi.c2
-rw-r--r--drivers/slimbus/messaging.c2
-rw-r--r--drivers/uio/uio_hv_generic.c72
-rw-r--r--drivers/virt/vboxguest/vboxguest_core.c70
-rw-r--r--drivers/virt/vboxguest/vboxguest_core.h9
-rw-r--r--drivers/virt/vboxguest/vboxguest_linux.c19
-rw-r--r--drivers/virt/vboxguest/vboxguest_utils.c17
-rw-r--r--include/linux/vbox_utils.h23
11 files changed, 124 insertions, 121 deletions
diff --git a/MAINTAINERS b/MAINTAINERS
index 1901ef510b43..3e41e12a88a4 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -905,6 +905,8 @@ ANDROID ION DRIVER
 M:	Laura Abbott <labbott@redhat.com>
 M:	Sumit Semwal <sumit.semwal@linaro.org>
 L:	devel@driverdev.osuosl.org
+L:	dri-devel@lists.freedesktop.org
+L:	linaro-mm-sig@lists.linaro.org (moderated for non-subscribers)
 S:	Supported
 F:	drivers/staging/android/ion
 F:	drivers/staging/android/uapi/ion.h
@@ -13953,7 +13955,7 @@ THUNDERBOLT DRIVER
 M:	Andreas Noever <andreas.noever@gmail.com>
 M:	Michael Jamet <michael.jamet@intel.com>
 M:	Mika Westerberg <mika.westerberg@linux.intel.com>
-M:	Yehezkel Bernat <yehezkel.bernat@intel.com>
+M:	Yehezkel Bernat <YehezkelShB@gmail.com>
 T:	git git://git.kernel.org/pub/scm/linux/kernel/git/westeri/thunderbolt.git
 S:	Maintained
 F:	Documentation/admin-guide/thunderbolt.rst
@@ -13963,7 +13965,7 @@ F:	include/linux/thunderbolt.h
 THUNDERBOLT NETWORK DRIVER
 M:	Michael Jamet <michael.jamet@intel.com>
 M:	Mika Westerberg <mika.westerberg@linux.intel.com>
-M:	Yehezkel Bernat <yehezkel.bernat@intel.com>
+M:	Yehezkel Bernat <YehezkelShB@gmail.com>
 L:	netdev@vger.kernel.org
 S:	Maintained
 F:	drivers/net/thunderbolt.c
diff --git a/drivers/amba/bus.c b/drivers/amba/bus.c
index 594c228d2f02..4a3ac31c07d0 100644
--- a/drivers/amba/bus.c
+++ b/drivers/amba/bus.c
@@ -69,11 +69,12 @@ static ssize_t driver_override_show(struct device *_dev,
 				    struct device_attribute *attr, char *buf)
 {
 	struct amba_device *dev = to_amba_device(_dev);
+	ssize_t len;
 
-	if (!dev->driver_override)
-		return 0;
-
-	return sprintf(buf, "%s\n", dev->driver_override);
+	device_lock(_dev);
+	len = sprintf(buf, "%s\n", dev->driver_override);
+	device_unlock(_dev);
+	return len;
 }
 
 static ssize_t driver_override_store(struct device *_dev,
@@ -81,9 +82,10 @@ static ssize_t driver_override_store(struct device *_dev,
 				     const char *buf, size_t count)
 {
 	struct amba_device *dev = to_amba_device(_dev);
-	char *driver_override, *old = dev->driver_override, *cp;
+	char *driver_override, *old, *cp;
 
-	if (count > PATH_MAX)
+	/* We need to keep extra room for a newline */
+	if (count >= (PAGE_SIZE - 1))
 		return -EINVAL;
 
 	driver_override = kstrndup(buf, count, GFP_KERNEL);
@@ -94,12 +96,15 @@ static ssize_t driver_override_store(struct device *_dev,
 	if (cp)
 		*cp = '\0';
 
+	device_lock(_dev);
+	old = dev->driver_override;
 	if (strlen(driver_override)) {
 		dev->driver_override = driver_override;
 	} else {
 	       kfree(driver_override);
 	       dev->driver_override = NULL;
 	}
+	device_unlock(_dev);
 
 	kfree(old);
 
diff --git a/drivers/android/binder.c b/drivers/android/binder.c
index 764b63a5aade..e578eee31589 100644
--- a/drivers/android/binder.c
+++ b/drivers/android/binder.c
@@ -2839,6 +2839,14 @@ static void binder_transaction(struct binder_proc *proc,
 			else
 				return_error = BR_DEAD_REPLY;
 			mutex_unlock(&context->context_mgr_node_lock);
+			if (target_node && target_proc == proc) {
+				binder_user_error("%d:%d got transaction to context manager from process owning it\n",
+						  proc->pid, thread->pid);
+				return_error = BR_FAILED_REPLY;
+				return_error_param = -EINVAL;
+				return_error_line = __LINE__;
+				goto err_invalid_target_handle;
+			}
 		}
 		if (!target_node) {
 			/*
diff --git a/drivers/fpga/altera-ps-spi.c b/drivers/fpga/altera-ps-spi.c
index 14f14efdf0d5..06d212a3d49d 100644
--- a/drivers/fpga/altera-ps-spi.c
+++ b/drivers/fpga/altera-ps-spi.c
@@ -249,7 +249,7 @@ static int altera_ps_probe(struct spi_device *spi)
 
 	conf->data = of_id->data;
 	conf->spi = spi;
-	conf->config = devm_gpiod_get(&spi->dev, "nconfig", GPIOD_OUT_HIGH);
+	conf->config = devm_gpiod_get(&spi->dev, "nconfig", GPIOD_OUT_LOW);
 	if (IS_ERR(conf->config)) {
 		dev_err(&spi->dev, "Failed to get config gpio: %ld\n",
 			PTR_ERR(conf->config));
diff --git a/drivers/slimbus/messaging.c b/drivers/slimbus/messaging.c
index 884419c37e84..457ea1f8db30 100644
--- a/drivers/slimbus/messaging.c
+++ b/drivers/slimbus/messaging.c
@@ -183,7 +183,7 @@ static u16 slim_slicesize(int code)
 		0, 1, 2, 3, 3, 4, 4, 5, 5, 5, 5, 6, 6, 6, 6, 7
 	};
 
-	clamp(code, 1, (int)ARRAY_SIZE(sizetocode));
+	code = clamp(code, 1, (int)ARRAY_SIZE(sizetocode));
 
 	return sizetocode[code - 1];
 }
diff --git a/drivers/uio/uio_hv_generic.c b/drivers/uio/uio_hv_generic.c
index f695a7e8c314..c690d100adcd 100644
--- a/drivers/uio/uio_hv_generic.c
+++ b/drivers/uio/uio_hv_generic.c
@@ -19,7 +19,7 @@
  * # echo -n "ed963694-e847-4b2a-85af-bc9cfc11d6f3" \
  *    > /sys/bus/vmbus/drivers/uio_hv_generic/bind
  */
-
+#define DEBUG 1
 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
 
 #include <linux/device.h>
@@ -94,10 +94,11 @@ hv_uio_irqcontrol(struct uio_info *info, s32 irq_state)
  */
 static void hv_uio_channel_cb(void *context)
 {
-	struct hv_uio_private_data *pdata = context;
-	struct hv_device *dev = pdata->device;
+	struct vmbus_channel *chan = context;
+	struct hv_device *hv_dev = chan->device_obj;
+	struct hv_uio_private_data *pdata = hv_get_drvdata(hv_dev);
 
-	dev->channel->inbound.ring_buffer->interrupt_mask = 1;
+	chan->inbound.ring_buffer->interrupt_mask = 1;
 	virt_mb();
 
 	uio_event_notify(&pdata->info);
@@ -121,78 +122,46 @@ static void hv_uio_rescind(struct vmbus_channel *channel)
 	uio_event_notify(&pdata->info);
 }
 
-/*
- * Handle fault when looking for sub channel ring buffer
- * Subchannel ring buffer is same as resource 0 which is main ring buffer
- * This is derived from uio_vma_fault
+/* Sysfs API to allow mmap of the ring buffers
+ * The ring buffer is allocated as contiguous memory by vmbus_open
  */
-static int hv_uio_vma_fault(struct vm_fault *vmf)
-{
-	struct vm_area_struct *vma = vmf->vma;
-	void *ring_buffer = vma->vm_private_data;
-	struct page *page;
-	void *addr;
-
-	addr = ring_buffer + (vmf->pgoff << PAGE_SHIFT);
-	page = virt_to_page(addr);
-	get_page(page);
-	vmf->page = page;
-	return 0;
-}
-
-static const struct vm_operations_struct hv_uio_vm_ops = {
-	.fault = hv_uio_vma_fault,
-};
-
-/* Sysfs API to allow mmap of the ring buffers */
 static int hv_uio_ring_mmap(struct file *filp, struct kobject *kobj,
 			    struct bin_attribute *attr,
 			    struct vm_area_struct *vma)
 {
 	struct vmbus_channel *channel
 		= container_of(kobj, struct vmbus_channel, kobj);
-	unsigned long requested_pages, actual_pages;
-
-	if (vma->vm_end < vma->vm_start)
-		return -EINVAL;
-
-	/* only allow 0 for now */
-	if (vma->vm_pgoff > 0)
-		return -EINVAL;
+	struct hv_device *dev = channel->primary_channel->device_obj;
+	u16 q_idx = channel->offermsg.offer.sub_channel_index;
 
-	requested_pages = vma_pages(vma);
-	actual_pages = 2 * HV_RING_SIZE;
-	if (requested_pages > actual_pages)
-		return -EINVAL;
+	dev_dbg(&dev->device, "mmap channel %u pages %#lx at %#lx\n",
+		q_idx, vma_pages(vma), vma->vm_pgoff);
 
-	vma->vm_private_data = channel->ringbuffer_pages;
-	vma->vm_flags |= VM_DONTEXPAND | VM_DONTDUMP;
-	vma->vm_ops = &hv_uio_vm_ops;
-	return 0;
+	return vm_iomap_memory(vma, virt_to_phys(channel->ringbuffer_pages),
+			       channel->ringbuffer_pagecount << PAGE_SHIFT);
 }
 
-static struct bin_attribute ring_buffer_bin_attr __ro_after_init = {
+static const struct bin_attribute ring_buffer_bin_attr = {
 	.attr = {
 		.name = "ring",
 		.mode = 0600,
-		/* size is set at init time */
 	},
+	.size = 2 * HV_RING_SIZE * PAGE_SIZE,
 	.mmap = hv_uio_ring_mmap,
 };
 
-/* Callback from VMBUS subystem when new channel created. */
+/* Callback from VMBUS subsystem when new channel created. */
 static void
 hv_uio_new_channel(struct vmbus_channel *new_sc)
 {
 	struct hv_device *hv_dev = new_sc->primary_channel->device_obj;
 	struct device *device = &hv_dev->device;
-	struct hv_uio_private_data *pdata = hv_get_drvdata(hv_dev);
 	const size_t ring_bytes = HV_RING_SIZE * PAGE_SIZE;
 	int ret;
 
 	/* Create host communication ring */
 	ret = vmbus_open(new_sc, ring_bytes, ring_bytes, NULL, 0,
-			 hv_uio_channel_cb, pdata);
+			 hv_uio_channel_cb, new_sc);
 	if (ret) {
 		dev_err(device, "vmbus_open subchannel failed: %d\n", ret);
 		return;
@@ -234,7 +203,7 @@ hv_uio_probe(struct hv_device *dev,
 
 	ret = vmbus_open(dev->channel, HV_RING_SIZE * PAGE_SIZE,
 			 HV_RING_SIZE * PAGE_SIZE, NULL, 0,
-			 hv_uio_channel_cb, pdata);
+			 hv_uio_channel_cb, dev->channel);
 	if (ret)
 		goto fail;
 
@@ -326,6 +295,11 @@ hv_uio_probe(struct hv_device *dev,
 	vmbus_set_chn_rescind_callback(dev->channel, hv_uio_rescind);
 	vmbus_set_sc_create_callback(dev->channel, hv_uio_new_channel);
 
+	ret = sysfs_create_bin_file(&dev->channel->kobj, &ring_buffer_bin_attr);
+	if (ret)
+		dev_notice(&dev->device,
+			   "sysfs create ring bin file failed; %d\n", ret);
+
 	hv_set_drvdata(dev, pdata);
 
 	return 0;
diff --git a/drivers/virt/vboxguest/vboxguest_core.c b/drivers/virt/vboxguest/vboxguest_core.c
index 190dbf8cfcb5..2f3856a95856 100644
--- a/drivers/virt/vboxguest/vboxguest_core.c
+++ b/drivers/virt/vboxguest/vboxguest_core.c
@@ -114,7 +114,7 @@ static void vbg_guest_mappings_init(struct vbg_dev *gdev)
 	}
 
 out:
-	kfree(req);
+	vbg_req_free(req, sizeof(*req));
 	kfree(pages);
 }
 
@@ -144,7 +144,7 @@ static void vbg_guest_mappings_exit(struct vbg_dev *gdev)
 
 	rc = vbg_req_perform(gdev, req);
 
-	kfree(req);
+	vbg_req_free(req, sizeof(*req));
 
 	if (rc < 0) {
 		vbg_err("%s error: %d\n", __func__, rc);
@@ -214,8 +214,8 @@ static int vbg_report_guest_info(struct vbg_dev *gdev)
 	ret = vbg_status_code_to_errno(rc);
 
 out_free:
-	kfree(req2);
-	kfree(req1);
+	vbg_req_free(req2, sizeof(*req2));
+	vbg_req_free(req1, sizeof(*req1));
 	return ret;
 }
 
@@ -245,7 +245,7 @@ static int vbg_report_driver_status(struct vbg_dev *gdev, bool active)
 	if (rc == VERR_NOT_IMPLEMENTED)	/* Compatibility with older hosts. */
 		rc = VINF_SUCCESS;
 
-	kfree(req);
+	vbg_req_free(req, sizeof(*req));
 
 	return vbg_status_code_to_errno(rc);
 }
@@ -431,7 +431,7 @@ static int vbg_heartbeat_host_config(struct vbg_dev *gdev, bool enabled)
 	rc = vbg_req_perform(gdev, req);
 	do_div(req->interval_ns, 1000000); /* ns -> ms */
 	gdev->heartbeat_interval_ms = req->interval_ns;
-	kfree(req);
+	vbg_req_free(req, sizeof(*req));
 
 	return vbg_status_code_to_errno(rc);
 }
@@ -454,12 +454,6 @@ static int vbg_heartbeat_init(struct vbg_dev *gdev)
 	if (ret < 0)
 		return ret;
 
-	/*
-	 * Preallocate the request to use it from the timer callback because:
-	 *    1) on Windows vbg_req_alloc must be called at IRQL <= APC_LEVEL
-	 *       and the timer callback runs at DISPATCH_LEVEL;
-	 *    2) avoid repeated allocations.
-	 */
 	gdev->guest_heartbeat_req = vbg_req_alloc(
 					sizeof(*gdev->guest_heartbeat_req),
 					VMMDEVREQ_GUEST_HEARTBEAT);
@@ -481,8 +475,8 @@ static void vbg_heartbeat_exit(struct vbg_dev *gdev)
 {
 	del_timer_sync(&gdev->heartbeat_timer);
 	vbg_heartbeat_host_config(gdev, false);
-	kfree(gdev->guest_heartbeat_req);
-
+	vbg_req_free(gdev->guest_heartbeat_req,
+		     sizeof(*gdev->guest_heartbeat_req));
 }
 
 /**
@@ -543,7 +537,7 @@ static int vbg_reset_host_event_filter(struct vbg_dev *gdev,
 	if (rc < 0)
 		vbg_err("%s error, rc: %d\n", __func__, rc);
 
-	kfree(req);
+	vbg_req_free(req, sizeof(*req));
 	return vbg_status_code_to_errno(rc);
 }
 
@@ -617,7 +611,7 @@ static int vbg_set_session_event_filter(struct vbg_dev *gdev,
 
 out:
 	mutex_unlock(&gdev->session_mutex);
-	kfree(req);
+	vbg_req_free(req, sizeof(*req));
 
 	return ret;
 }
@@ -642,7 +636,7 @@ static int vbg_reset_host_capabilities(struct vbg_dev *gdev)
 	if (rc < 0)
 		vbg_err("%s error, rc: %d\n", __func__, rc);
 
-	kfree(req);
+	vbg_req_free(req, sizeof(*req));
 	return vbg_status_code_to_errno(rc);
 }
 
@@ -712,7 +706,7 @@ static int vbg_set_session_capabilities(struct vbg_dev *gdev,
 
 out:
 	mutex_unlock(&gdev->session_mutex);
-	kfree(req);
+	vbg_req_free(req, sizeof(*req));
 
 	return ret;
 }
@@ -733,8 +727,10 @@ static int vbg_query_host_version(struct vbg_dev *gdev)
 
 	rc = vbg_req_perform(gdev, req);
 	ret = vbg_status_code_to_errno(rc);
-	if (ret)
+	if (ret) {
+		vbg_err("%s error: %d\n", __func__, rc);
 		goto out;
+	}
 
 	snprintf(gdev->host_version, sizeof(gdev->host_version), "%u.%u.%ur%u",
 		 req->major, req->minor, req->build, req->revision);
@@ -749,7 +745,7 @@ static int vbg_query_host_version(struct vbg_dev *gdev)
 	}
 
 out:
-	kfree(req);
+	vbg_req_free(req, sizeof(*req));
 	return ret;
 }
 
@@ -847,11 +843,16 @@ int vbg_core_init(struct vbg_dev *gdev, u32 fixed_events)
 	return 0;
 
 err_free_reqs:
-	kfree(gdev->mouse_status_req);
-	kfree(gdev->ack_events_req);
-	kfree(gdev->cancel_req);
-	kfree(gdev->mem_balloon.change_req);
-	kfree(gdev->mem_balloon.get_req);
+	vbg_req_free(gdev->mouse_status_req,
+		     sizeof(*gdev->mouse_status_req));
+	vbg_req_free(gdev->ack_events_req,
+		     sizeof(*gdev->ack_events_req));
+	vbg_req_free(gdev->cancel_req,
+		     sizeof(*gdev->cancel_req));
+	vbg_req_free(gdev->mem_balloon.change_req,
+		     sizeof(*gdev->mem_balloon.change_req));
+	vbg_req_free(gdev->mem_balloon.get_req,
+		     sizeof(*gdev->mem_balloon.get_req));
 	return ret;
 }
 
@@ -872,11 +873,16 @@ void vbg_core_exit(struct vbg_dev *gdev)
 	vbg_reset_host_capabilities(gdev);
 	vbg_core_set_mouse_status(gdev, 0);
 
-	kfree(gdev->mouse_status_req);
-	kfree(gdev->ack_events_req);
-	kfree(gdev->cancel_req);
-	kfree(gdev->mem_balloon.change_req);
-	kfree(gdev->mem_balloon.get_req);
+	vbg_req_free(gdev->mouse_status_req,
+		     sizeof(*gdev->mouse_status_req));
+	vbg_req_free(gdev->ack_events_req,
+		     sizeof(*gdev->ack_events_req));
+	vbg_req_free(gdev->cancel_req,
+		     sizeof(*gdev->cancel_req));
+	vbg_req_free(gdev->mem_balloon.change_req,
+		     sizeof(*gdev->mem_balloon.change_req));
+	vbg_req_free(gdev->mem_balloon.get_req,
+		     sizeof(*gdev->mem_balloon.get_req));
 }
 
 /**
@@ -1415,7 +1421,7 @@ static int vbg_ioctl_write_core_dump(struct vbg_dev *gdev,
 	req->flags = dump->u.in.flags;
 	dump->hdr.rc = vbg_req_perform(gdev, req);
 
-	kfree(req);
+	vbg_req_free(req, sizeof(*req));
 	return 0;
 }
 
@@ -1513,7 +1519,7 @@ int vbg_core_set_mouse_status(struct vbg_dev *gdev, u32 features)
 	if (rc < 0)
 		vbg_err("%s error, rc: %d\n", __func__, rc);
 
-	kfree(req);
+	vbg_req_free(req, sizeof(*req));
 	return vbg_status_code_to_errno(rc);
 }
 
diff --git a/drivers/virt/vboxguest/vboxguest_core.h b/drivers/virt/vboxguest/vboxguest_core.h
index 6c784bf4fa6d..7ad9ec45bfa9 100644
--- a/drivers/virt/vboxguest/vboxguest_core.h
+++ b/drivers/virt/vboxguest/vboxguest_core.h
@@ -171,4 +171,13 @@ irqreturn_t vbg_core_isr(int irq, void *dev_id);
 
 void vbg_linux_mouse_event(struct vbg_dev *gdev);
 
+/* Private (non exported) functions form vboxguest_utils.c */
+void *vbg_req_alloc(size_t len, enum vmmdev_request_type req_type);
+void vbg_req_free(void *req, size_t len);
+int vbg_req_perform(struct vbg_dev *gdev, void *req);
+int vbg_hgcm_call32(
+	struct vbg_dev *gdev, u32 client_id, u32 function, u32 timeout_ms,
+	struct vmmdev_hgcm_function_parameter32 *parm32, u32 parm_count,
+	int *vbox_status);
+
 #endif
diff --git a/drivers/virt/vboxguest/vboxguest_linux.c b/drivers/virt/vboxguest/vboxguest_linux.c
index 82e280d38cc2..398d22693234 100644
--- a/drivers/virt/vboxguest/vboxguest_linux.c
+++ b/drivers/virt/vboxguest/vboxguest_linux.c
@@ -87,6 +87,7 @@ static long vbg_misc_device_ioctl(struct file *filp, unsigned int req,
 	struct vbg_session *session = filp->private_data;
 	size_t returned_size, size;
 	struct vbg_ioctl_hdr hdr;
+	bool is_vmmdev_req;
 	int ret = 0;
 	void *buf;
 
@@ -106,8 +107,17 @@ static long vbg_misc_device_ioctl(struct file *filp, unsigned int req,
 	if (size > SZ_16M)
 		return -E2BIG;
 
-	/* __GFP_DMA32 because IOCTL_VMMDEV_REQUEST passes this to the host */
-	buf = kmalloc(size, GFP_KERNEL | __GFP_DMA32);
+	/*
+	 * IOCTL_VMMDEV_REQUEST needs the buffer to be below 4G to avoid
+	 * the need for a bounce-buffer and another copy later on.
+	 */
+	is_vmmdev_req = (req & ~IOCSIZE_MASK) == VBG_IOCTL_VMMDEV_REQUEST(0) ||
+			 req == VBG_IOCTL_VMMDEV_REQUEST_BIG;
+
+	if (is_vmmdev_req)
+		buf = vbg_req_alloc(size, VBG_IOCTL_HDR_TYPE_DEFAULT);
+	else
+		buf = kmalloc(size, GFP_KERNEL);
 	if (!buf)
 		return -ENOMEM;
 
@@ -132,7 +142,10 @@ static long vbg_misc_device_ioctl(struct file *filp, unsigned int req,
 		ret = -EFAULT;
 
 out:
-	kfree(buf);
+	if (is_vmmdev_req)
+		vbg_req_free(buf, size);
+	else
+		kfree(buf);
 
 	return ret;
 }
diff --git a/drivers/virt/vboxguest/vboxguest_utils.c b/drivers/virt/vboxguest/vboxguest_utils.c
index 0f0dab8023cf..bf4474214b4d 100644
--- a/drivers/virt/vboxguest/vboxguest_utils.c
+++ b/drivers/virt/vboxguest/vboxguest_utils.c
@@ -65,8 +65,9 @@ VBG_LOG(vbg_debug, pr_debug);
 void *vbg_req_alloc(size_t len, enum vmmdev_request_type req_type)
 {
 	struct vmmdev_request_header *req;
+	int order = get_order(PAGE_ALIGN(len));
 
-	req = kmalloc(len, GFP_KERNEL | __GFP_DMA32);
+	req = (void *)__get_free_pages(GFP_KERNEL | GFP_DMA32, order);
 	if (!req)
 		return NULL;
 
@@ -82,6 +83,14 @@ void *vbg_req_alloc(size_t len, enum vmmdev_request_type req_type)
 	return req;
 }
 
+void vbg_req_free(void *req, size_t len)
+{
+	if (!req)
+		return;
+
+	free_pages((unsigned long)req, get_order(PAGE_ALIGN(len)));
+}
+
 /* Note this function returns a VBox status code, not a negative errno!! */
 int vbg_req_perform(struct vbg_dev *gdev, void *req)
 {
@@ -137,7 +146,7 @@ int vbg_hgcm_connect(struct vbg_dev *gdev,
 		rc = hgcm_connect->header.result;
 	}
 
-	kfree(hgcm_connect);
+	vbg_req_free(hgcm_connect, sizeof(*hgcm_connect));
 
 	*vbox_status = rc;
 	return 0;
@@ -166,7 +175,7 @@ int vbg_hgcm_disconnect(struct vbg_dev *gdev, u32 client_id, int *vbox_status)
 	if (rc >= 0)
 		rc = hgcm_disconnect->header.result;
 
-	kfree(hgcm_disconnect);
+	vbg_req_free(hgcm_disconnect, sizeof(*hgcm_disconnect));
 
 	*vbox_status = rc;
 	return 0;
@@ -623,7 +632,7 @@ int vbg_hgcm_call(struct vbg_dev *gdev, u32 client_id, u32 function,
 	}
 
 	if (!leak_it)
-		kfree(call);
+		vbg_req_free(call, size);
 
 free_bounce_bufs:
 	if (bounce_bufs) {
diff --git a/include/linux/vbox_utils.h b/include/linux/vbox_utils.h
index c71def6b310f..a240ed2a0372 100644
--- a/include/linux/vbox_utils.h
+++ b/include/linux/vbox_utils.h
@@ -24,24 +24,6 @@ __printf(1, 2) void vbg_debug(const char *fmt, ...);
 #define vbg_debug pr_debug
 #endif
 
-/**
- * Allocate memory for generic request and initialize the request header.
- *
- * Return: the allocated memory
- * @len:		Size of memory block required for the request.
- * @req_type:		The generic request type.
- */
-void *vbg_req_alloc(size_t len, enum vmmdev_request_type req_type);
-
-/**
- * Perform a generic request.
- *
- * Return: VBox status code
- * @gdev:		The Guest extension device.
- * @req:		Pointer to the request structure.
- */
-int vbg_req_perform(struct vbg_dev *gdev, void *req);
-
 int vbg_hgcm_connect(struct vbg_dev *gdev,
 		     struct vmmdev_hgcm_service_location *loc,
 		     u32 *client_id, int *vbox_status);
@@ -52,11 +34,6 @@ int vbg_hgcm_call(struct vbg_dev *gdev, u32 client_id, u32 function,
 		  u32 timeout_ms, struct vmmdev_hgcm_function_parameter *parms,
 		  u32 parm_count, int *vbox_status);
 
-int vbg_hgcm_call32(
-	struct vbg_dev *gdev, u32 client_id, u32 function, u32 timeout_ms,
-	struct vmmdev_hgcm_function_parameter32 *parm32, u32 parm_count,
-	int *vbox_status);
-
 /**
  * Convert a VirtualBox status code to a standard Linux kernel return value.
  * Return: 0 or negative errno value.