From: Alex Williamson <alex.williamson@redhat.com>
Date: Wed, 1 Dec 2021 16:45:41 -0700
Subject: vfio/pci: Resolve sparse endian warnings in IGD support
Git-commit: 21ab799585762e097387da82a4e0fd6c2ffb4000
Patch-mainline: v5.17-rc1
References: bsc#1205701
Sparse warns:
sparse warnings: (new ones prefixed by >>)
>> drivers/vfio/pci/vfio_pci_igd.c:146:21: sparse: sparse: incorrect type in assignment (different base types) @@ expected unsigned short [addressable] [usertype] val @@ got restricted __le16 [usertype] @@
drivers/vfio/pci/vfio_pci_igd.c:146:21: sparse: expected unsigned short [addressable] [usertype] val
drivers/vfio/pci/vfio_pci_igd.c:146:21: sparse: got restricted __le16 [usertype]
>> drivers/vfio/pci/vfio_pci_igd.c:161:21: sparse: sparse: incorrect type in assignment (different base types) @@ expected unsigned int [addressable] [usertype] val @@ got restricted __le32 [usertype] @@
drivers/vfio/pci/vfio_pci_igd.c:161:21: sparse: expected unsigned int [addressable] [usertype] val
drivers/vfio/pci/vfio_pci_igd.c:161:21: sparse: got restricted __le32 [usertype]
drivers/vfio/pci/vfio_pci_igd.c:176:21: sparse: sparse: incorrect type in assignment (different base types) @@ expected unsigned short [addressable] [usertype] val @@ got restricted __le16 [usertype] @@
drivers/vfio/pci/vfio_pci_igd.c:176:21: sparse: expected unsigned short [addressable] [usertype] val
drivers/vfio/pci/vfio_pci_igd.c:176:21: sparse: got restricted __le16 [usertype]
These are due to trying to use an unsigned to store the result of
a cpu_to_leXX() conversion. These are small variables, so pointer
tricks are wasteful and casting just generates different sparse
warnings. Store to and copy results from a separate little endian
variable.
Reported-by: kernel test robot <lkp@intel.com>
Link: https://lore.kernel.org/r/202111290026.O3vehj03-lkp@intel.com/
Link: https://lore.kernel.org/r/163840226123.138003.7668320168896210328.stgit@omen
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Acked-by: Joerg Roedel <jroedel@suse.de>
---
drivers/vfio/pci/vfio_pci_igd.c | 15 +++++++++------
1 file changed, 9 insertions(+), 6 deletions(-)
diff --git a/drivers/vfio/pci/vfio_pci_igd.c b/drivers/vfio/pci/vfio_pci_igd.c
index 362f91ec8845..352c725ccf18 100644
--- a/drivers/vfio/pci/vfio_pci_igd.c
+++ b/drivers/vfio/pci/vfio_pci_igd.c
@@ -309,13 +309,14 @@ static ssize_t vfio_pci_igd_cfg_rw(struct vfio_pci_core_device *vdev,
if ((pos & 3) && size > 2) {
u16 val;
+ __le16 lval;
ret = pci_user_read_config_word(pdev, pos, &val);
if (ret)
return ret;
- val = cpu_to_le16(val);
- if (copy_to_user(buf + count - size, &val, 2))
+ lval = cpu_to_le16(val);
+ if (copy_to_user(buf + count - size, &lval, 2))
return -EFAULT;
pos += 2;
@@ -324,13 +325,14 @@ static ssize_t vfio_pci_igd_cfg_rw(struct vfio_pci_core_device *vdev,
while (size > 3) {
u32 val;
+ __le32 lval;
ret = pci_user_read_config_dword(pdev, pos, &val);
if (ret)
return ret;
- val = cpu_to_le32(val);
- if (copy_to_user(buf + count - size, &val, 4))
+ lval = cpu_to_le32(val);
+ if (copy_to_user(buf + count - size, &lval, 4))
return -EFAULT;
pos += 4;
@@ -339,13 +341,14 @@ static ssize_t vfio_pci_igd_cfg_rw(struct vfio_pci_core_device *vdev,
while (size >= 2) {
u16 val;
+ __le16 lval;
ret = pci_user_read_config_word(pdev, pos, &val);
if (ret)
return ret;
- val = cpu_to_le16(val);
- if (copy_to_user(buf + count - size, &val, 2))
+ lval = cpu_to_le16(val);
+ if (copy_to_user(buf + count - size, &lval, 2))
return -EFAULT;
pos += 2;