release/5.2.53/virt-vbox-Fix-VBGL_IOCTL_VMMDEV_REQUEST_BIG-and-_LOG.patch

From c45491eba6562dc62dc81d4486589a58e90ce2c0 Mon Sep 17 00:00:00 2001
From: Hans de Goede <hdegoede@redhat.com>
Date: Thu, 9 Jul 2020 14:08:51 +0200
Subject: [PATCH] virt: vbox: Fix VBGL_IOCTL_VMMDEV_REQUEST_BIG and _LOG req
 numbers to match upstream

commit f794db6841e5480208f0c3a3ac1df445a96b079e upstream.

Until this commit the mainline kernel version (this version) of the
vboxguest module contained a bug where it defined
VBGL_IOCTL_VMMDEV_REQUEST_BIG and VBGL_IOCTL_LOG using
_IOC(_IOC_READ | _IOC_WRITE, 'V', ...) instead of
_IO(V, ...) as the out of tree VirtualBox upstream version does.

Since the VirtualBox userspace bits are always built against VirtualBox
upstream's headers, this means that so far the mainline kernel version
of the vboxguest module has been failing these 2 ioctls with -ENOTTY.
I guess that VBGL_IOCTL_VMMDEV_REQUEST_BIG is never used causing us to
not hit that one and sofar the vboxguest driver has failed to actually
log any log messages passed it through VBGL_IOCTL_LOG.

This commit changes the VBGL_IOCTL_VMMDEV_REQUEST_BIG and VBGL_IOCTL_LOG
defines to match the out of tree VirtualBox upstream vboxguest version,
while keeping compatibility with the old wrong request defines so as
to not break the kernel ABI in case someone has been using the old
request defines.

Fixes: f6ddd094f579 ("virt: Add vboxguest driver for Virtual Box Guest integration UAPI")
Cc: stable@vger.kernel.org
Acked-by: Arnd Bergmann <arnd@arndb.de>
Reviewed-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Link: https://lore.kernel.org/r/20200709120858.63928-2-hdegoede@redhat.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>

diff --git a/drivers/virt/vboxguest/vboxguest_core.c b/drivers/virt/vboxguest/vboxguest_core.c
index 2307b0329aec..4eb8ea36093a 100644
--- a/drivers/virt/vboxguest/vboxguest_core.c
+++ b/drivers/virt/vboxguest/vboxguest_core.c
@@ -1519,7 +1519,8 @@ int vbg_core_ioctl(struct vbg_session *session, unsigned int req, void *data)
 
 	/* For VMMDEV_REQUEST hdr->type != VBG_IOCTL_HDR_TYPE_DEFAULT */
 	if (req_no_size == VBG_IOCTL_VMMDEV_REQUEST(0) ||
-	    req == VBG_IOCTL_VMMDEV_REQUEST_BIG)
+	    req == VBG_IOCTL_VMMDEV_REQUEST_BIG ||
+	    req == VBG_IOCTL_VMMDEV_REQUEST_BIG_ALT)
 		return vbg_ioctl_vmmrequest(gdev, session, data);
 
 	if (hdr->type != VBG_IOCTL_HDR_TYPE_DEFAULT)
@@ -1557,6 +1558,7 @@ int vbg_core_ioctl(struct vbg_session *session, unsigned int req, void *data)
 	case VBG_IOCTL_HGCM_CALL(0):
 		return vbg_ioctl_hgcm_call(gdev, session, f32bit, data);
 	case VBG_IOCTL_LOG(0):
+	case VBG_IOCTL_LOG_ALT(0):
 		return vbg_ioctl_log(data);
 	}
 
diff --git a/drivers/virt/vboxguest/vboxguest_core.h b/drivers/virt/vboxguest/vboxguest_core.h
index 4188c12b839f..77c3a9c8255d 100644
--- a/drivers/virt/vboxguest/vboxguest_core.h
+++ b/drivers/virt/vboxguest/vboxguest_core.h
@@ -15,6 +15,21 @@
 #include <linux/vboxguest.h>
 #include "vmmdev.h"
 
+/*
+ * The mainline kernel version (this version) of the vboxguest module
+ * contained a bug where it defined VBGL_IOCTL_VMMDEV_REQUEST_BIG and
+ * VBGL_IOCTL_LOG using _IOC(_IOC_READ | _IOC_WRITE, 'V', ...) instead
+ * of _IO(V, ...) as the out of tree VirtualBox upstream version does.
+ *
+ * These _ALT definitions keep compatibility with the wrong defines the
+ * mainline kernel version used for a while.
+ * Note the VirtualBox userspace bits have always been built against
+ * VirtualBox upstream's headers, so this is likely not necessary. But
+ * we must never break our ABI so we keep these around to be 100% sure.
+ */
+#define VBG_IOCTL_VMMDEV_REQUEST_BIG_ALT _IOC(_IOC_READ | _IOC_WRITE, 'V', 3, 0)
+#define VBG_IOCTL_LOG_ALT(s)             _IOC(_IOC_READ | _IOC_WRITE, 'V', 9, s)
+
 struct vbg_session;
 
 /** VBox guest memory balloon. */
diff --git a/drivers/virt/vboxguest/vboxguest_linux.c b/drivers/virt/vboxguest/vboxguest_linux.c
index 6e8c0f1c1056..32c2c52f7e84 100644
--- a/drivers/virt/vboxguest/vboxguest_linux.c
+++ b/drivers/virt/vboxguest/vboxguest_linux.c
@@ -131,7 +131,8 @@ static long vbg_misc_device_ioctl(struct file *filp, unsigned int req,
 	 * 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;
+			 req == VBG_IOCTL_VMMDEV_REQUEST_BIG ||
+			 req == VBG_IOCTL_VMMDEV_REQUEST_BIG_ALT;
 
 	if (is_vmmdev_req)
 		buf = vbg_req_alloc(size, VBG_IOCTL_HDR_TYPE_DEFAULT,
diff --git a/include/uapi/linux/vboxguest.h b/include/uapi/linux/vboxguest.h
index 612f0c7d3558..ded39da305d0 100644
--- a/include/uapi/linux/vboxguest.h
+++ b/include/uapi/linux/vboxguest.h
@@ -103,7 +103,7 @@ VMMDEV_ASSERT_SIZE(vbg_ioctl_driver_version_info, 24 + 20);
 
 
 /* IOCTL to perform a VMM Device request larger then 1KB. */
-#define VBG_IOCTL_VMMDEV_REQUEST_BIG	_IOC(_IOC_READ | _IOC_WRITE, 'V', 3, 0)
+#define VBG_IOCTL_VMMDEV_REQUEST_BIG	_IO('V', 3)
 
 
 /** VBG_IOCTL_HGCM_CONNECT data structure. */
@@ -198,7 +198,7 @@ struct vbg_ioctl_log {
 	} u;
 };
 
-#define VBG_IOCTL_LOG(s)		_IOC(_IOC_READ | _IOC_WRITE, 'V', 9, s)
+#define VBG_IOCTL_LOG(s)		_IO('V', 9)
 
 
 /** VBG_IOCTL_WAIT_FOR_EVENTS data structure. */
-- 
2.27.0