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x86/PCI/ACPI: Relax ACPI resource descriptor checks to work around BIOS bugs

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Some BIOSes report incorrect length for ACPI address space descriptors,
so relax the checks to avoid regressions. This issue has appeared several
times as:
 3162b6f0c5 ("PNPACPI: truncate _CRS windows with _LEN > _MAX - _MIN + 1")
 d558b483d5 ("x86/PCI: truncate _CRS windows with _LEN > _MAX - _MIN + 1")
 f238b414a7 ("PNPACPI: compute Address Space length rather than using _LEN")
 48728e0774 ("x86/PCI: compute Address Space length rather than using _LEN")

Please refer to https://bugzilla.kernel.org/show_bug.cgi?id=94221
for more details and example malformed ACPI resource descriptors.

Link: https://bugzilla.kernel.org/show_bug.cgi?id=94221
Fixes: 593669c2ac (x86/PCI/ACPI: Use common ACPI resource interfaces ...)
Signed-off-by: Jiang Liu <jiang.liu@linux.intel.com>
Tested-by: Dave Airlie <airlied@redhat.com>
Tested-by: Prakash Punnoor <prakash@punnoor.de>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
This commit is contained in:
Jiang Liu 2015-03-04 16:47:12 +08:00 committed by Rafael J. Wysocki
parent 63f1789ec7
commit aa714d286f
1 changed files with 3 additions and 1 deletions
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4
drivers/acpi/resource.c
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@ -42,8 +42,10 @@ static bool acpi_dev_resource_len_valid(u64 start, u64 end, u64 len, bool io)
* CHECKME: len might be required to check versus a minimum
* length as well. 1 for io is fine, but for memory it does
* not make any sense at all.
* Note: some BIOSes report incorrect length for ACPI address space
* descriptor, so remove check of 'reslen == len' to avoid regression.
*/
if (len && reslen && reslen == len && start <= end)
if (len && reslen && start <= end)
return true;
pr_debug("ACPI: invalid or unassigned resource %s [%016llx - %016llx] length [%016llx]\n",