[SRU][N:linux-bluefield][PATCH v1 1/1] UBUNTU: SAUCE: Fix vfio_pci_core_ioctl compilation issue

[Stav Aviram]

BugLink: https://bugs.launchpad.net/bugs/2129689

Fix compilation error on x86_64 caused by a C standards violation in
the VFIO_DEVICE_P2P_DMA_BUF case handler.

During the port of commit 60da28814250 ("vfio/pci: Allow MMIO regions
to be exported through dma-buf") from linux-bluefield-5.15 to 6.8, the
vfio_pci_core_ioctl function structure changed from an if-else chain to
a switch statement. The adaptation converted the original
'else if (cmd == VFIO_DEVICE_P2P_DMA_BUF)' to a case label but did not
add the necessary braces around the case block.

In C, a case label cannot be directly followed by a variable declaration
without an intervening compound statement. This violates C language
standards (C89/C90/C99/C11), causing compilation failures on x86_64 with
certain compiler configurations:

  drivers/vfio/pci/vfio_pci_core.c:1489:3: error: a label can only be
  part of a statement and a declaration is not a statement

The fix adds braces to create a compound statement around the case block,
making the code standards-compliant without changing any logic.

Fixes: 60da28814250 ("vfio/pci: Allow MMIO regions to be exported through dma-buf")
Signed-off-by: Stav Aviram <saviram at nvidia.com>
---
 drivers/vfio/pci/vfio_pci_core.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/vfio/pci/vfio_pci_core.c b/drivers/vfio/pci/vfio_pci_core.c
index d015e65ef988..40fc0607e45f 100644
--- a/drivers/vfio/pci/vfio_pci_core.c
+++ b/drivers/vfio/pci/vfio_pci_core.c
@@ -1485,13 +1485,14 @@ long vfio_pci_core_ioctl(struct vfio_device *core_vdev, unsigned int cmd,
 		return vfio_pci_ioctl_reset(vdev, uarg);
 	case VFIO_DEVICE_SET_IRQS:
 		return vfio_pci_ioctl_set_irqs(vdev, uarg);
-	case VFIO_DEVICE_P2P_DMA_BUF:
+	case VFIO_DEVICE_P2P_DMA_BUF: {
 		struct vfio_device_p2p_dma_buf p2p_dma_buf;
 
 		if (copy_from_user(&p2p_dma_buf, uarg, sizeof(p2p_dma_buf)))
 			return -EFAULT;
 
 		return vfio_pci_core_feature_dma_buf(vdev, &p2p_dma_buf);
+	}
 	default:
 		return -ENOTTY;
 	}
-- 
2.38.1