On 01/15/2010 03:32 PM, Myron Stowe wrote:
> Alex Williamson pointed out that the IOH_VTBAR read, as currently
> implemented, could silently fail and, if this occurred, 'dword' would
> be -1. Under these conditions the check of whether or not the VTBAR
> was enabled - if (dword & 0x1 && ... - would be incorrectly interpreted
> as true. Thus began the slippery slope of adding checks to register
> reads.
>
> Signed-off-by: Myron Stowe <myron.stowe@xxxxxx>
> ---
>
> arch/x86/pci/intel_bus.c | 31 ++++++++++++++++---------------
> 1 files changed, 16 insertions(+), 15 deletions(-)
>
> diff --git a/arch/x86/pci/intel_bus.c b/arch/x86/pci/intel_bus.c
> index 8be4e1d..07d773d 100644
> --- a/arch/x86/pci/intel_bus.c
> +++ b/arch/x86/pci/intel_bus.c
> @@ -46,40 +46,37 @@ static void __devinit pci_root_bus_res(struct pci_dev *dev)
> {
> u16 word;
> u32 dword;
> - struct pci_root_info *info;
> + struct pci_root_info tmp, *info = &tmp;
> u16 io_base, io_end;
> u32 mmiol_base, mmiol_end, vtbar;
> u64 mmioh_base, mmioh_end;
> int bus_base, bus_end;
>
> - /* some sys doesn't get mmconf enabled */
> - if (dev->cfg_size < 0x120)
> - return;
> -
> if (pci_root_num >= PCI_ROOT_NR) {
> printk(KERN_DEBUG "intel_bus.c: PCI_ROOT_NR is too small\n");
> return;
> }
>
> - info = &pci_root_info[pci_root_num];
> - pci_root_num++;
> -
> - pci_read_config_word(dev, IOH_LCFGBUS, &word);
> + if (pci_read_config_word(dev, IOH_LCFGBUS, &word))
> + return;
> bus_base = (word & 0xff);
> bus_end = (word & 0xff00) >> 8;
> sprintf(info->name, "PCI Bus #%02x", bus_base);
> info->bus_min = bus_base;
> info->bus_max = bus_end;
>
> - pci_read_config_word(dev, IOH_LIO, &word);
> + if (pci_read_config_word(dev, IOH_LIO, &word))
> + return;
> io_base = (word & 0xf0) << (12 - 4);
> io_end = (word & 0xf000) | 0xfff;
> update_res(info, io_base, io_end, IORESOURCE_IO, 0);
>
> - pci_read_config_dword(dev, IOH_LMMIOL, &dword);
> + if (pci_read_config_dword(dev, IOH_LMMIOL, &dword))
> + return;
> mmiol_base = (dword & 0xff00) << (24 - 8);
> mmiol_end = (dword & 0xff000000) | 0xffffff;
> - pci_read_config_dword(dev, IOH_VTBAR, &dword);
> + if (pci_read_config_dword(dev, IOH_VTBAR, &dword))
> + return;
> vtbar = dword & 0xfffffffe;
> if (dword & 0x1 &&
> (mmiol_base < vtbar + IOH_VTSIZE - 1 && vtbar < mmiol_end)) {
> @@ -96,15 +93,19 @@ static void __devinit pci_root_bus_res(struct pci_dev *dev)
> }
> update_res(info, mmiol_base, mmiol_end, IORESOURCE_MEM, 0);
>
> - pci_read_config_dword(dev, IOH_LMMIOH, &dword);
> + if (pci_read_config_dword(dev, IOH_LMMIOH, &dword))
> + return;
> mmioh_base = ((u64)(dword & 0xfc00)) << (26 - 10);
> mmioh_end = ((u64)(dword & 0xfc000000) | 0x3ffffff);
> - pci_read_config_dword(dev, IOH_LMMIOH_BASEU, &dword);
> + if (pci_read_config_dword(dev, IOH_LMMIOH_BASEU, &dword))
> + return;
> mmioh_base |= ((u64)(dword & 0x7ffff)) << 32;
> - pci_read_config_dword(dev, IOH_LMMIOH_LIMITU, &dword);
> + if (pci_read_config_dword(dev, IOH_LMMIOH_LIMITU, &dword))
> + return;
> mmioh_end |= ((u64)(dword & 0x7ffff)) << 32;
> update_res(info, mmioh_base, mmioh_end, IORESOURCE_MEM, 0);
>
> + pci_root_info[pci_root_num++] = *info;
> print_ioh_resources(info);
> }
>
can you just read last one like IOH_VTBAR to see if need to get out?
too much return here...
YH
--
To unsubscribe from this list: send the line "unsubscribe linux-pci" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
