2021-03-05 03:00:56

by Kishon Vijay Abraham I

Subject: [PATCH] PCI: designware-ep: Fix NULL pointer dereference error

commit 281f1f99cf3a ("PCI: dwc: Detect number of iATU windows") detected
the number of inbound and outbound windows dynamically at runtime in
dw_pcie_setup(). However pcie-designware-ep.c accessed the variables
holding the number of inbound and outbound windows even before
dw_pcie_setup() was invoked. Fix the sequence here.

Fixes: 281f1f99cf3a ("PCI: dwc: Detect number of iATU windows")
Signed-off-by: Kishon Vijay Abraham I <[email protected]>
---
.../pci/controller/dwc/pcie-designware-ep.c | 44 ++++++++++---------
1 file changed, 23 insertions(+), 21 deletions(-)

diff --git a/drivers/pci/controller/dwc/pcie-designware-ep.c b/drivers/pci/controller/dwc/pcie-designware-ep.c
index 1c25d8337151..2c0f837af458 100644
--- a/drivers/pci/controller/dwc/pcie-designware-ep.c
+++ b/drivers/pci/controller/dwc/pcie-designware-ep.c
@@ -636,9 +636,11 @@ static unsigned int dw_pcie_ep_find_ext_capability(struct dw_pcie *pci, int cap)
int dw_pcie_ep_init_complete(struct dw_pcie_ep *ep)
{
struct dw_pcie *pci = to_dw_pcie_from_ep(ep);
+ struct device *dev = pci->dev;
unsigned int offset;
unsigned int nbars;
u8 hdr_type;
+ void *addr;
u32 reg;
int i;

@@ -665,6 +667,27 @@ int dw_pcie_ep_init_complete(struct dw_pcie_ep *ep)
}

dw_pcie_setup(pci);
+
+ ep->ib_window_map = devm_kcalloc(dev,
+ BITS_TO_LONGS(pci->num_ib_windows),
+ sizeof(long),
+ GFP_KERNEL);
+ if (!ep->ib_window_map)
+ return -ENOMEM;
+
+ ep->ob_window_map = devm_kcalloc(dev,
+ BITS_TO_LONGS(pci->num_ob_windows),
+ sizeof(long),
+ GFP_KERNEL);
+ if (!ep->ob_window_map)
+ return -ENOMEM;
+
+ addr = devm_kcalloc(dev, pci->num_ob_windows, sizeof(phys_addr_t),
+ GFP_KERNEL);
+ if (!addr)
+ return -ENOMEM;
+ ep->outbound_addr = addr;
+
dw_pcie_dbi_ro_wr_dis(pci);

return 0;
@@ -674,7 +697,6 @@ EXPORT_SYMBOL_GPL(dw_pcie_ep_init_complete);
int dw_pcie_ep_init(struct dw_pcie_ep *ep)
{
int ret;
- void *addr;
u8 func_no;
struct resource *res;
struct pci_epc *epc;
@@ -712,26 +734,6 @@ int dw_pcie_ep_init(struct dw_pcie_ep *ep)
ep->phys_base = res->start;
ep->addr_size = resource_size(res);

- ep->ib_window_map = devm_kcalloc(dev,
- BITS_TO_LONGS(pci->num_ib_windows),
- sizeof(long),
- GFP_KERNEL);
- if (!ep->ib_window_map)
- return -ENOMEM;
-
- ep->ob_window_map = devm_kcalloc(dev,
- BITS_TO_LONGS(pci->num_ob_windows),
- sizeof(long),
- GFP_KERNEL);
- if (!ep->ob_window_map)
- return -ENOMEM;
-
- addr = devm_kcalloc(dev, pci->num_ob_windows, sizeof(phys_addr_t),
- GFP_KERNEL);
- if (!addr)
- return -ENOMEM;
- ep->outbound_addr = addr;
-
if (pci->link_gen < 1)
pci->link_gen = of_pci_get_max_link_speed(np);

--
2.17.1

2021-03-05 16:22:00

by Rob Herring (Arm)

Subject: Re: [PATCH] PCI: designware-ep: Fix NULL pointer dereference error

On Thu, Mar 4, 2021 at 8:59 PM Kishon Vijay Abraham I <[email protected]> wrote:
>
> commit 281f1f99cf3a ("PCI: dwc: Detect number of iATU windows") detected
> the number of inbound and outbound windows dynamically at runtime in
> dw_pcie_setup(). However pcie-designware-ep.c accessed the variables
> holding the number of inbound and outbound windows even before
> dw_pcie_setup() was invoked. Fix the sequence here.
>
> Fixes: 281f1f99cf3a ("PCI: dwc: Detect number of iATU windows")
> Signed-off-by: Kishon Vijay Abraham I <[email protected]>
> ---
> .../pci/controller/dwc/pcie-designware-ep.c | 44 ++++++++++---------
> 1 file changed, 23 insertions(+), 21 deletions(-)

There's already another fix posted. I prodded Bjorn to apply it.

Rob