From: Ben Hutchings <ben@decadent.org.uk>
Date: Tue, 16 Feb 2016 02:45:42 +0000 (+0000)
Subject: [i386/686-pae] PCI: Set pci=nobios by default
X-Git-Tag: archive/raspbian/5.10.226-1+rpi1^2~17
X-Git-Url: https://dgit.raspbian.org/?a=commitdiff_plain;h=407396a5342457db50c5c8e493d813a870266059;p=linux.git

[i386/686-pae] PCI: Set pci=nobios by default

Forwarded: not-needed

CONFIG_PCI_GOBIOS results in physical addresses 640KB-1MB being mapped
W+X, which is undesirable for security reasons and will result in a
warning at boot now that we enable CONFIG_DEBUG_WX.

This can be overridden using the kernel parameter "pci=nobios", but we
want to disable W+X by default.  Disable PCI BIOS probing by default;
it can still be enabled using "pci=bios".


Gbp-Pq: Topic debian
Gbp-Pq: Name i386-686-pae-pci-set-pci-nobios-by-default.patch
---

diff --git a/arch/x86/pci/common.c b/arch/x86/pci/common.c
index 3507f456fcd..132be4c569a 100644
--- a/arch/x86/pci/common.c
+++ b/arch/x86/pci/common.c
@@ -21,8 +21,8 @@
 #include <asm/setup.h>
 #include <asm/irqdomain.h>
 
-unsigned int pci_probe = PCI_PROBE_BIOS | PCI_PROBE_CONF1 | PCI_PROBE_CONF2 |
-				PCI_PROBE_MMCONF;
+unsigned int pci_probe = PCI_PROBE_CONF1 | PCI_PROBE_CONF2 | PCI_PROBE_MMCONF |
+	(IS_ENABLED(CONFIG_X86_64) || IS_ENABLED(CONFIG_X86_PAE) ? 0 : PCI_PROBE_BIOS);
 
 static int pci_bf_sort;
 int pci_routeirq;