pci_get_device() decrements the reference count of "from" (last argument) so when we break off the loop successfully we have only one device reference - and we don't know which device we have. If we want a reference to each device, we must take them explicitly and let the pci_get_device() walk complete to avoid duplicate references. This is serious, as over-putting device references will cause the device to eventually disappear. Without this fix, the kernel crashes after a few insmod/rmmod cycles. Tested on an Intel S7000FC4UR system with a 7300 chipset. Signed-off-by: Jean Delvare <jdelvare@xxxxxxx> Link: http://lkml.kernel.org/r/20140224111656.09bbb7ed@endymion.delvare Cc: Mauro Carvalho Chehab <m.chehab@xxxxxxxxxxx> Cc: Doug Thompson <dougthompson@xxxxxxxxxxxx> Cc: stable@xxxxxxxxxxxxxxx Signed-off-by: Borislav Petkov <bp@xxxxxxx> --- This is commit 75135da0d68419ef8a925f4c1d5f63d8046e314d upstream, backported to kernel v3.4 (context change only.) drivers/edac/i7300_edac.c | 38 ++++++++++++++++++++------------------ 1 file changed, 20 insertions(+), 18 deletions(-) --- linux-3.4.orig/drivers/edac/i7300_edac.c 2014-03-09 12:13:38.091024876 +0100 +++ linux-3.4/drivers/edac/i7300_edac.c 2014-03-09 12:13:44.664174725 +0100 @@ -962,33 +962,35 @@ static int __devinit i7300_get_devices(s /* Attempt to 'get' the MCH register we want */ pdev = NULL; - while (!pvt->pci_dev_16_1_fsb_addr_map || - !pvt->pci_dev_16_2_fsb_err_regs) { - pdev = pci_get_device(PCI_VENDOR_ID_INTEL, - PCI_DEVICE_ID_INTEL_I7300_MCH_ERR, pdev); - if (!pdev) { - /* End of list, leave */ - i7300_printk(KERN_ERR, - "'system address,Process Bus' " - "device not found:" - "vendor 0x%x device 0x%x ERR funcs " - "(broken BIOS?)\n", - PCI_VENDOR_ID_INTEL, - PCI_DEVICE_ID_INTEL_I7300_MCH_ERR); - goto error; - } - + while ((pdev = pci_get_device(PCI_VENDOR_ID_INTEL, + PCI_DEVICE_ID_INTEL_I7300_MCH_ERR, + pdev))) { /* Store device 16 funcs 1 and 2 */ switch (PCI_FUNC(pdev->devfn)) { case 1: - pvt->pci_dev_16_1_fsb_addr_map = pdev; + if (!pvt->pci_dev_16_1_fsb_addr_map) + pvt->pci_dev_16_1_fsb_addr_map = + pci_dev_get(pdev); break; case 2: - pvt->pci_dev_16_2_fsb_err_regs = pdev; + if (!pvt->pci_dev_16_2_fsb_err_regs) + pvt->pci_dev_16_2_fsb_err_regs = + pci_dev_get(pdev); break; } } + if (!pvt->pci_dev_16_1_fsb_addr_map || + !pvt->pci_dev_16_2_fsb_err_regs) { + /* At least one device was not found */ + i7300_printk(KERN_ERR, + "'system address,Process Bus' device not found:" + "vendor 0x%x device 0x%x ERR funcs (broken BIOS?)\n", + PCI_VENDOR_ID_INTEL, + PCI_DEVICE_ID_INTEL_I7300_MCH_ERR); + goto error; + } + debugf1("System Address, processor bus- PCI Bus ID: %s %x:%x\n", pci_name(pvt->pci_dev_16_0_fsb_ctlr), pvt->pci_dev_16_0_fsb_ctlr->vendor, -- Jean Delvare SUSE L3 Support -- To unsubscribe from this list: send the line "unsubscribe stable" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html