[PATCH v2 1/4] powerpc/4xx: Fix exception handling in ppc4xx_pciex_port_setup_hose()

[Markus Elfring]

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 at 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)
--
2.40.0