linux-kernel - Re: PCI MSI breaks when booting with nosmp

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

Date:	Mon, 21 Apr 2008 14:14:44 -0700
From:	Jesse Barnes <jbarnes@...tuousgeek.org>
To:	Andi Kleen <andi@...stfloor.org>
Cc:	Jean Delvare <jdelvare@...e.de>,
	linux-pci@...ey.karlin.mff.cuni.cz,
	LKML <linux-kernel@...r.kernel.org>, Pavel Machek <pavel@....cz>,
	Tejun Heo <htejun@...il.com>,
	Tom Long Nguyen <tom.l.nguyen@...el.com>,
	Randy Dunlap <rdunlap@...otime.net>,
	Jeff Garzik <jgarzik@...ox.com>
Subject: Re: PCI MSI breaks when booting with nosmp

On Monday, April 21, 2008 2:09 pm Andi Kleen wrote:
> > Both call disable_ioapic_setup(), so how can they not be the same?
>
> See Jesse's explanation. Basically there is special code in the smp
> boot up to handle 0 CPUs and it disables all APICs.
>
> This is very old and crufty and somewhat obsolete logic,
> but it is like that.

This might be closer to a real fix.  Can you confirm that this works for you 
Jean?

Thanks,
Jesse

diff --git a/arch/x86/kernel/smpboot.c b/arch/x86/kernel/smpboot.c
index e6abe8a..7cdf930 100644
--- a/arch/x86/kernel/smpboot.c
+++ b/arch/x86/kernel/smpboot.c
@@ -1138,14 +1138,10 @@ static int __init smp_sanity_check(unsigned max_cpus)
 				 "forcing use of dummy APIC emulation.\n");
 		smpboot_clear_io_apic();
 #ifdef CONFIG_X86_32
-		if (nmi_watchdog == NMI_LOCAL_APIC) {
-			printk(KERN_INFO "activating minimal APIC for"
-					 "NMI watchdog use.\n");
-			connect_bsp_APIC();
-			setup_local_APIC();
-			end_local_APIC_setup();
-		}
+		connect_bsp_APIC();
 #endif
+		setup_local_APIC();
+		end_local_APIC_setup();
 		return -1;
 	}
 

--
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/