[PATCH 1/4] powerpc/4xx: Fix exception handling in ppc4xx_pciex_port_setup_hose()

[Markus Elfring <Markus.Elfring@web.de>]

Date: Thu, 16 Mar 2023 19:00:57 +0100

The label “fail” was used to jump to another pointer check despite of
the detail in the implementation of the function “ppc4xx_pciex_port_setup_hose”
that it was determined already that the corresponding variable contained
a null pointer (because of a failed function call in three cases).

1. Thus return directly after a call of the function “pcibios_alloc_controller” failed.

2. Use more appropriate labels instead.

3. Reorder jump targets at the end.

4. Delete two questionable checks.

This issue was detected by using the Coccinelle software.

Fixes: a2d2e1ec07a80946cbe812dc8c73291cad8214b2 ("[POWERPC] 4xx: PLB to PCI Express support")
Fixes: 80daac3f86d4f5aafc9d3e79addb90fa118244e2 ("[POWERPC] 4xx: Add endpoint support to 4xx PCIe driver")
Signed-off-by: Markus Elfring <elfring@users.sourceforge.net>
---
 arch/powerpc/platforms/4xx/pci.c | 19 ++++++++++---------
 1 file changed, 10 insertions(+), 9 deletions(-)

diff --git a/arch/powerpc/platforms/4xx/pci.c b/arch/powerpc/platforms/4xx/pci.c
index ca5dd7a5842a..7336c7039b10 100644
--- a/arch/powerpc/platforms/4xx/pci.c
+++ b/arch/powerpc/platforms/4xx/pci.c
@@ -1930,7 +1930,7 @@ static void __init ppc4xx_pciex_port_setup_hose(struct ppc4xx_pciex_port *port)
     /* Allocate the host controller data structure */
     hose = pcibios_alloc_controller(port->node);
     if (!hose)
-        goto fail;
+        return;
 
     /* We stick the port number in "indirect_type" so the config space
      * ops can retrieve the port data structure easily
@@ -1962,7 +1962,7 @@ static void __init ppc4xx_pciex_port_setup_hose(struct ppc4xx_pciex_port *port)
         if (cfg_data == NULL) {
             printk(KERN_ERR "%pOF: Can't map external config space !",
                    port->node);
-            goto fail;
+            goto free_controller;
         }
         hose->cfg_data = cfg_data;
     }
@@ -1974,7 +1974,7 @@ static void __init ppc4xx_pciex_port_setup_hose(struct ppc4xx_pciex_port *port)
     if (mbase == NULL) {
         printk(KERN_ERR "%pOF: Can't map internal config space !",
                port->node);
-        goto fail;
+        goto recheck_cfg_data;
     }
     hose->cfg_addr = mbase;
 
@@ -2007,7 +2007,7 @@ static void __init ppc4xx_pciex_port_setup_hose(struct ppc4xx_pciex_port *port)
 
     /* Parse inbound mapping resources */
     if (ppc4xx_parse_dma_ranges(hose, mbase, &dma_window) != 0)
-        goto fail;
+        goto unmap_io_mbase;
 
     /* Configure outbound ranges POMs */
     ppc4xx_configure_pciex_POMs(port, hose, mbase);
@@ -2064,13 +2064,14 @@ static void __init ppc4xx_pciex_port_setup_hose(struct ppc4xx_pciex_port *port)
     }
 
     return;
- fail:
-    if (hose)
-        pcibios_free_controller(hose);
+
+unmap_io_mbase:
+    iounmap(mbase);
+recheck_cfg_data:
     if (cfg_data)
         iounmap(cfg_data);
-    if (mbase)
-        iounmap(mbase);
+free_controller:
+    pcibios_free_controller(hose);
 }
 
 static void __init ppc4xx_probe_pciex_bridge(struct device_node *np)
--
2.39.2