[PATCH v4 1/2] PCI: dwc: Fix a 64bit bug in dw_pcie_ep_raise_msix_irq()

From: Dan Carpenter
Date: Wed Jan 24 2024 - 10:02:11 EST


The "msg_addr" variable is u64. However, the "aligned_offset" is an
unsigned int. This means that when the code does:

msg_addr &= ~aligned_offset;

it will unintentionally zero out the high 32 bits. Use ALIGN_DOWN()
to do the alignment instead.

Cc: stable@xxxxxxxxxxxxxxx
Fixes: 2217fffcd63f ("PCI: dwc: endpoint: Fix dw_pcie_ep_raise_msix_irq() alignment support")
Signed-off-by: Dan Carpenter <dan.carpenter@xxxxxxxxxx>
Reviewed-by: Niklas Cassel <cassel@xxxxxxxxxx>
---
v4: Add stable and r-b from Niklas
v3: Use ALIGN_DOWN()
v2: fix typo in commit message

drivers/pci/controller/dwc/pcie-designware-ep.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/pci/controller/dwc/pcie-designware-ep.c b/drivers/pci/controller/dwc/pcie-designware-ep.c
index 5befed2dc02b..51679c6702cf 100644
--- a/drivers/pci/controller/dwc/pcie-designware-ep.c
+++ b/drivers/pci/controller/dwc/pcie-designware-ep.c
@@ -551,7 +551,7 @@ int dw_pcie_ep_raise_msix_irq(struct dw_pcie_ep *ep, u8 func_no,
}

aligned_offset = msg_addr & (epc->mem->window.page_size - 1);
- msg_addr &= ~aligned_offset;
+ msg_addr = ALIGN_DOWN(msg_addr, epc->mem->window.page_size);
ret = dw_pcie_ep_map_addr(epc, func_no, 0, ep->msi_mem_phys, msg_addr,
epc->mem->window.page_size);
if (ret)
--
2.43.0