re: [PATCH] PCI: add proper MCFG table parsing to ACPI core.

[Konrad Rzeszutek <konradr@redhat.com>]

Hey Greg,

This a bit late (yours patch was posted about a year ago), but
a co-worker of spotted part of the code that looks like a memory
leak. Looking at the code it seems that pci_mmcfg_config should
be free-ed if MMCONFIG is above 4GB.

> +/* The physical address of the MMCONFIG aperture.  Set from ACPI
> tables. */
> +     config_size = pci_mmcfg_config_num * sizeof(*pci_mmcfg_config);
> +     pci_mmcfg_config = kmalloc(config_size, GFP_KERNEL);
> +     memcpy(pci_mmcfg_config, &mcfg->config, config_size);
> +     for (i = 0; i < pci_mmcfg_config_num; ++i) {
> +             if (mcfg->config[i].base_reserved) {
> +                     printk(KERN_ERR PREFIX
> +                            "MMCONFIG not in low 4GB of memory\n");
> +                     return -ENODEV;

Here is a proposed patch. What are your thoughts?

diff --git a/arch/i386/kernel/acpi/boot.c b/arch/i386/kernel/acpi/boot.c
index 40e5aba..fbe9308 100644
--- a/arch/i386/kernel/acpi/boot.c
+++ b/arch/i386/kernel/acpi/boot.c
@@ -202,6 +202,8 @@ int __init acpi_parse_mcfg(unsigned long
 		if (mcfg->config[i].base_reserved) {
 			printk(KERN_ERR PREFIX
 			       "MMCONFIG not in low 4GB of memory\n");
+			kfree(pci_mmcfg_config);
+			pci_mmcfg_config_num = 0;
 			return -ENODEV;
 		}
 	}