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| author | Jean Delvare <jdelvare@suse.de> | 2014-02-25 09:43:13 +0100 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2014-03-06 22:06:29 -0800 |
| commit | d8c2a97e20d1c4e726c21b2eac32a0258ff9ede0 (patch) | |
| tree | 770cf0cc84e84a9caaf78b73930ee7ec8731f093 | |
| parent | b7dd2bb40cc2e8eb357d772a55c36b762794dfe2 (diff) | |
| download | lwn-d8c2a97e20d1c4e726c21b2eac32a0258ff9ede0.tar.gz lwn-d8c2a97e20d1c4e726c21b2eac32a0258ff9ede0.zip | |
i7300_edac: Fix device reference count
commit 75135da0d68419ef8a925f4c1d5f63d8046e314d upstream.
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@suse.de>
Link: http://lkml.kernel.org/r/20140224111656.09bbb7ed@endymion.delvare
Cc: Mauro Carvalho Chehab <m.chehab@samsung.com>
Cc: Doug Thompson <dougthompson@xmission.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | drivers/edac/i7300_edac.c | 38 |
1 files changed, 20 insertions, 18 deletions
diff --git a/drivers/edac/i7300_edac.c b/drivers/edac/i7300_edac.c index 9004c64b169e..841eee387478 100644 --- a/drivers/edac/i7300_edac.c +++ b/drivers/edac/i7300_edac.c @@ -943,33 +943,35 @@ static int i7300_get_devices(struct mem_ctl_info *mci) /* 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; + } + edac_dbg(1, "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, |