[PATCH v2 3/4] powerpc/4xx: Fix exception handling in ppc4xx_probe_pci_bridge()

[Markus Elfring]

Date: Sat, 25 Mar 2023 15:56:09 +0100

The label “fail” was used to jump to another pointer check despite of
the detail in the implementation of the function “ppc4xx_probe_pci_bridge”
that it was determined already that the corresponding variable contained
a null pointer (because of a failed function call in two cases).

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

2. Use a more appropriate label instead.

3. Delete two questionable checks.

4. Adjust the exception handling for another if branch a bit more.

5. Remove a return statement at the end.


This issue was detected by using the Coccinelle software.

Fixes: c839e0eff500af03de65e560c2e21c3831586e6e ("[POWERPC] 4xx: PLB to PCI 2.x support")
Signed-off-by: Markus Elfring <elfring at users.sourceforge.net>
---
V3:
A closing parenthesis (which was overlooked somehow) was preserved
for an if statement.

 arch/powerpc/platforms/4xx/pci.c | 18 +++++++-----------
 1 file changed, 7 insertions(+), 11 deletions(-)

diff --git a/arch/powerpc/platforms/4xx/pci.c b/arch/powerpc/platforms/4xx/pci.c
index fdf13e12ca9d..46ba0a4e5b04 100644
--- a/arch/powerpc/platforms/4xx/pci.c
+++ b/arch/powerpc/platforms/4xx/pci.c
@@ -358,13 +358,13 @@ static void __init ppc4xx_probe_pci_bridge(struct device_node *np)
 	reg = ioremap(rsrc_reg.start, resource_size(&rsrc_reg));
 	if (reg == NULL) {
 		printk(KERN_ERR "%pOF: Can't map registers !", np);
-		goto fail;
+		return;
 	}

 	/* Allocate the host controller data structure */
 	hose = pcibios_alloc_controller(np);
 	if (!hose)
-		goto fail;
+		goto unmap_io;

 	hose->first_busno = bus_range ? bus_range[0] : 0x0;
 	hose->last_busno = bus_range ? bus_range[1] : 0xff;
@@ -383,8 +383,10 @@ static void __init ppc4xx_probe_pci_bridge(struct device_node *np)
 	pci_process_bridge_OF_ranges(hose, np, primary);

 	/* Parse inbound mapping resources */
-	if (ppc4xx_parse_dma_ranges(hose, reg, &dma_window) != 0)
-		goto fail;
+	if (ppc4xx_parse_dma_ranges(hose, reg, &dma_window)) {
+		pcibios_free_controller(hose);
+		goto unmap_io;
+	}

 	/* Configure outbound ranges POMs */
 	ppc4xx_configure_pci_PMMs(hose, reg);
@@ -393,14 +395,8 @@ static void __init ppc4xx_probe_pci_bridge(struct device_node *np)
 	ppc4xx_configure_pci_PTMs(hose, reg, &dma_window);

 	/* We don't need the registers anymore */
+unmap_io:
 	iounmap(reg);
-	return;
-
- fail:
-	if (hose)
-		pcibios_free_controller(hose);
-	if (reg)
-		iounmap(reg);
 }

 /*
--
2.40.0