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authorHans de Goede <hdegoede@redhat.com>2018-04-18 15:24:49 +0200
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2018-04-23 13:41:55 +0200
commitfaf6a2a44164c0fb2c2a82692ab9051917514bce (patch)
treeb7ed81ebf85416b394564e24e2200aa751934358 /drivers/virt
parentf6f9885b0531163f72c7bf898a0ab1ba4c7d5de6 (diff)
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virt: vbox: Use __get_free_pages instead of kmalloc for DMA32 memory
It is not possible to get DMA32 zone memory through kmalloc, causing the vboxguest driver to malfunction due to getting memory above 4G which the PCI device cannot handle. This commit changes the kmalloc calls where the 4G limit matters to using __get_free_pages() fixing vboxguest not working on x86_64 guests with more then 4G RAM. Cc: stable@vger.kernel.org Reported-by: Eloy Coto Pereiro <eloy.coto@gmail.com> Signed-off-by: Hans de Goede <hdegoede@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/virt')
-rw-r--r--drivers/virt/vboxguest/vboxguest_linux.c19
-rw-r--r--drivers/virt/vboxguest/vboxguest_utils.c5
2 files changed, 19 insertions, 5 deletions
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 bad915463359..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;
@@ -87,7 +88,7 @@ void vbg_req_free(void *req, size_t len)
if (!req)
return;
- kfree(req);
+ free_pages((unsigned long)req, get_order(PAGE_ALIGN(len)));
}
/* Note this function returns a VBox status code, not a negative errno!! */