linux-kernel - [PATCH 5/5] x86, x2apic: Don't map lapic addr for preenabled x2apic system

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: <4CFDF69C.9070501@kernel.org>
Date:	Tue, 07 Dec 2010 00:55:56 -0800
From:	Yinghai Lu <yinghai@...nel.org>
To:	Thomas Gleixner <tglx@...utronix.de>, Ingo Molnar <mingo@...e.hu>,
	"H. Peter Anvin" <hpa@...or.com>
CC:	Suresh Siddha <suresh.b.siddha@...el.com>,
	"Eric W. Biederman" <ebiederm@...ssion.com>,
	"linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>
Subject: [PATCH 5/5] x86, x2apic: Don't map lapic addr for preenabled x2apic
 system


If x2apic is reenabled, and used in kernel, We don't need to map that lapic
address. That mapping will never be used.

So just skip that in register_lapic_address()

Signed-off-by: Yinghai Lu <yinghai@...nel.org>

---
 arch/x86/kernel/apic/apic.c |    8 +++++---
 1 file changed, 5 insertions(+), 3 deletions(-)

Index: linux-2.6/arch/x86/kernel/apic/apic.c
===================================================================
--- linux-2.6.orig/arch/x86/kernel/apic/apic.c
+++ linux-2.6/arch/x86/kernel/apic/apic.c
@@ -1676,9 +1676,11 @@ void __init register_lapic_address(unsig
 {
 	mp_lapic_addr = address;
 
-	set_fixmap_nocache(FIX_APIC_BASE, address);
-	apic_printk(APIC_VERBOSE, "mapped APIC to %16lx (%16lx)\n",
-		    APIC_BASE, mp_lapic_addr);
+	if (!x2apic_mode) {
+		set_fixmap_nocache(FIX_APIC_BASE, address);
+		apic_printk(APIC_VERBOSE, "mapped APIC to %16lx (%16lx)\n",
+			    APIC_BASE, mp_lapic_addr);
+	}
 	if (boot_cpu_physical_apicid == -1U) {
 		boot_cpu_physical_apicid  = read_apic_id();
 		apic_version[boot_cpu_physical_apicid] =
--
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/