[PATCH] [parisc] superio: Add error handling for request_region in superio_init

From: Haoran Liu
Date: Wed Nov 29 2023 - 10:26:52 EST


This patch introduces error handling for the request_region call in the
superio_init function within drivers/parisc/superio.c. Prior to this patch,
the function did not handle the scenario where request_region might fail,
potentially leading to resource conflicts.

Although the error addressed by this patch may not occur in the current
environment, I still suggest implementing these error handling routines
if the function is not highly time-sensitive. As the environment evolves
or the code gets reused in different contexts, there's a possibility that
these errors might occur. Addressing them now can prevent potential
debugging efforts in the future, which could be quite resource-intensive.

Signed-off-by: Haoran Liu <liuhaoran14@xxxxxxx>
---
drivers/parisc/superio.c | 20 +++++++++++++++++---
1 file changed, 17 insertions(+), 3 deletions(-)

diff --git a/drivers/parisc/superio.c b/drivers/parisc/superio.c
index e973c6893203..36c01e70671d 100644
--- a/drivers/parisc/superio.c
+++ b/drivers/parisc/superio.c
@@ -187,9 +187,23 @@ superio_init(struct pci_dev *pcidev)
sio->acpi_base &= ~1;
printk(KERN_INFO PFX "ACPI at 0x%x\n", sio->acpi_base);

- request_region (IC_PIC1, 0x1f, "pic1");
- request_region (IC_PIC2, 0x1f, "pic2");
- request_region (sio->acpi_base, 0x1f, "acpi");
+ if (!request_region(IC_PIC1, 0x1f, "pic1")) {
+ printk(KERN_ERR PFX "request_region failed for pic1\n");
+ return;
+ }
+
+ if (!request_region(IC_PIC2, 0x1f, "pic2")) {
+ printk(KERN_ERR PFX "request_region failed for pic2\n");
+ release_region(IC_PIC1, 0x1f);
+ return;
+ }
+
+ if (!request_region(sio->acpi_base, 0x1f, "acpi")) {
+ printk(KERN_ERR PFX "request_region failed for acpi\n");
+ release_region(IC_PIC1, 0x1f);
+ release_region(IC_PIC2, 0x1f);
+ return;
+ }

/* Enable the legacy I/O function */
pci_read_config_word (pdev, PCI_COMMAND, &word);
--
2.17.1