diff mbox series

[3/7] pci: designware: clamp viewport index

Message ID 20220713165449.37433-4-ben.dooks@sifive.com (mailing list archive)
State New, archived
Headers show
Series [1/7] pci: designware: add 64-bit viewport limit | expand

Commit Message

Ben Dooks July 13, 2022, 4:54 p.m. UTC 
The current Linux driver for this assumes it can write the 255 into
this register and then read back the value to work out how many
viewports are supported.

Clamp the value so that the probe works and does not cause memory
corruption as the value is not well clamped elsewhere in the driver.

Signed-off-by: Ben Dooks <ben.dooks@sifive.com>
---
 hw/pci-host/designware.c | 4 ++++
 1 file changed, 4 insertions(+)
diff mbox series

Patch

diff --git a/hw/pci-host/designware.c b/hw/pci-host/designware.c
index d213d7324c..6403416634 100644
--- a/hw/pci-host/designware.c
+++ b/hw/pci-host/designware.c
@@ -345,6 +345,10 @@  static void designware_pcie_root_config_write(PCIDevice *d, uint32_t address,
         break;
 
     case DESIGNWARE_PCIE_ATU_VIEWPORT:
+        /* clamp this value, linux uses it to calculate the
+         * available number of viewports */
+        if (val >= DESIGNWARE_PCIE_NUM_VIEWPORTS)
+            val = DESIGNWARE_PCIE_NUM_VIEWPORTS-1;
         root->atu_viewport = val;
         break;