linux-kernel - [PATCH 2/3] xen: reserve ISA space in e820 map

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>] [day] [month] [year] [list]

Date:	Mon, 16 Jun 2008 14:54:49 -0700
From:	Jeremy Fitzhardinge <jeremy@...p.org>
To:	the arch/x86 maintainers <x86@...nel.org>
CC:	Yinghai Lu <yhlu.kernel@...il.com>,
	Linux Kernel Mailing List <linux-kernel@...r.kernel.org>
Subject: [PATCH 2/3] xen: reserve ISA space in e820 map

Even though the ISA space is perfectly normal, usable RAM under
Xen, too many random pieces of code want to poke in there for stuff.
Previously we added the memory on either side to the e820 map as RAM,
leaving the ISA hole completely absent.  However, now that we're using
sanitize_e820_map() to clean things up, it's a bit neater to claim all
of memory as RAM, and then mark E820_RESERVED ranges within it.

[ TODO: release the underlying memory back to Xen. ]

Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@...rix.com>
Cc: Yinghai Lu <yhlu.kernel@...il.com>
Cc: Ian Campbell <ian.campbell@...rix.com>
---
 arch/x86/xen/setup.c |   12 ++++++++++--
 1 file changed, 10 insertions(+), 2 deletions(-)

===================================================================
--- a/arch/x86/xen/setup.c
+++ b/arch/x86/xen/setup.c
@@ -13,6 +13,7 @@
 #include <asm/vdso.h>
 #include <asm/e820.h>
 #include <asm/setup.h>
+#include <asm/acpi.h>
 #include <asm/xen/hypervisor.h>
 #include <asm/xen/hypercall.h>
 
@@ -41,8 +42,15 @@
 
 	e820.nr_map = 0;
 
-	e820_add_region(0, LOWMEMSIZE(), E820_RAM);
-	e820_add_region(HIGH_MEMORY, PFN_PHYS(max_pfn)-HIGH_MEMORY, E820_RAM);
+	e820_add_region(0, PFN_PHYS(max_pfn), E820_RAM);
+
+	/*
+	 * Even though this is normal, usable memory under Xen, reserve
+	 * ISA memory anyway because too many things think they can poke
+	 * about in there.
+	 */
+	e820_add_region(ISA_START_ADDRESS, ISA_END_ADDRESS - ISA_START_ADDRESS,
+			E820_RESERVED);
 
 	/*
 	 * Reserve Xen bits:


--
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/