[tip:x86/cleanups] lguest: Read length of device_cap later
From: tip-bot for Paul Bolle
Date: Fri Jun 10 2016 - 05:43:23 EST
Commit-ID: 7faf90ef995ea470f32f43810266ece8ac8ba6c7
Gitweb: http://git.kernel.org/tip/7faf90ef995ea470f32f43810266ece8ac8ba6c7
Author: Paul Bolle <pebolle@xxxxxxxxxx>
AuthorDate: Thu, 3 Mar 2016 13:01:40 +0100
Committer: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
CommitDate: Fri, 10 Jun 2016 11:39:09 +0200
lguest: Read length of device_cap later
Read the length of the capability with type VIRTIO_PCI_CAP_DEVICE_CFG
only when we're sure we're going to need it. Which is just before the
check whether the virtio console actually has an emerg_wr field.
Signed-off-by: Paul Bolle <pebolle@xxxxxxxxxx>
Cc: Rusty Russell <rusty@xxxxxxxxxxxxxxx>
Cc: lguest@xxxxxxxxxxxxxxxx
Link: http://lkml.kernel.org/r/1457006501-5377-2-git-send-email-pebolle@xxxxxxxxxx
Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
---
arch/x86/lguest/boot.c | 7 +++----
1 file changed, 3 insertions(+), 4 deletions(-)
diff --git a/arch/x86/lguest/boot.c b/arch/x86/lguest/boot.c
index 3847e73..146d11c 100644
--- a/arch/x86/lguest/boot.c
+++ b/arch/x86/lguest/boot.c
@@ -1258,7 +1258,7 @@ static void probe_pci_console(void)
u8 vndr = read_pci_config_byte(0, 1, 0, cap);
if (vndr == PCI_CAP_ID_VNDR) {
u8 type, bar;
- u32 offset, length;
+ u32 offset;
type = read_pci_config_byte(0, 1, 0,
cap + offsetof(struct virtio_pci_cap, cfg_type));
@@ -1266,15 +1266,12 @@ static void probe_pci_console(void)
cap + offsetof(struct virtio_pci_cap, bar));
offset = read_pci_config(0, 1, 0,
cap + offsetof(struct virtio_pci_cap, offset));
- length = read_pci_config(0, 1, 0,
- cap + offsetof(struct virtio_pci_cap, length));
switch (type) {
case VIRTIO_PCI_CAP_DEVICE_CFG:
if (bar == 0) {
device_cap = cap;
device_offset = offset;
- device_len = length;
}
break;
case VIRTIO_PCI_CAP_PCI_CFG:
@@ -1297,6 +1294,8 @@ static void probe_pci_console(void)
* emerg_wr. If it doesn't support VIRTIO_CONSOLE_F_EMERG_WRITE
* it should ignore the access.
*/
+ device_len = read_pci_config(0, 1, 0,
+ device_cap + offsetof(struct virtio_pci_cap, length));
if (device_len < (offsetof(struct virtio_console_config, emerg_wr)
+ sizeof(u32))) {
printk(KERN_ERR "lguest: console missing emerg_wr field\n");