linux-kernel - [PATCH] x86/PCI: ignore Consumer/Producer bit in ACPI window descriptions

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [thread-next>] [day] [month] [year] [list]

Message-ID: <20100406192408.14676.17106.stgit@bob.kio>
Date:	Tue, 06 Apr 2010 13:24:08 -0600
From:	Bjorn Helgaas <bjorn.helgaas@...com>
To:	Jesse Barnes <jbarnes@...tuousgeek.org>
Cc:	linux-pci@...r.kernel.org, linux-kernel@...r.kernel.org,
	Thomas Renninger <trenn@...e.de>
Subject: [PATCH] x86/PCI: ignore Consumer/Producer bit in ACPI window
	descriptions


ACPI Address Space Descriptors (used in _CRS) have a Consumer/Producer
bit that is supposed to distinguish regions that are consumed directly
by a device from those that are forwarded ("produced") by a bridge.
But BIOSes have apparently not used this consistently, and Windows
seems to ignore it, so I think Linux should ignore it as well.

I can't point to any of these supposed broken BIOSes, but since we
now rely on _CRS by default, I think it's safer to ignore this bit
from the start.

Here are details of my experiments with how Windows handles it:
    https://bugzilla.kernel.org/show_bug.cgi?id=15701

Signed-off-by: Bjorn Helgaas <bjorn.helgaas@...com>
---

 arch/x86/pci/acpi.c |    3 +--
 1 files changed, 1 insertions(+), 2 deletions(-)


diff --git a/arch/x86/pci/acpi.c b/arch/x86/pci/acpi.c
index c7b1ebf..334153c 100644
--- a/arch/x86/pci/acpi.c
+++ b/arch/x86/pci/acpi.c
@@ -71,8 +71,7 @@ resource_to_addr(struct acpi_resource *resource,
 	if (ACPI_SUCCESS(status) &&
 	    (addr->resource_type == ACPI_MEMORY_RANGE ||
 	    addr->resource_type == ACPI_IO_RANGE) &&
-	    addr->address_length > 0 &&
-	    addr->producer_consumer == ACPI_PRODUCER) {
+	    addr->address_length > 0) {
 		return AE_OK;
 	}
 	return AE_ERROR;

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/