linux-kernel - [patch 12/58] x86/of: Fix the APIC address registration

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]

Message-ID: <20230717223223.795705685@linutronix.de>
Date:   Tue, 18 Jul 2023 01:14:52 +0200 (CEST)
From:   Thomas Gleixner <tglx@...utronix.de>
To:     LKML <linux-kernel@...r.kernel.org>
Cc:     x86@...nel.org, Linus Torvalds <torvalds@...ux-foundation.org>,
        Andrew Cooper <andrew.cooper3@...rix.com>,
        Tom Lendacky <thomas.lendacky@....com>,
        Paolo Bonzini <pbonzini@...hat.com>,
        Wei Liu <wei.liu@...nel.org>,
        Arjan van de Ven <arjan@...ux.intel.com>,
        Juergen Gross <jgross@...e.com>
Subject: [patch 12/58] x86/of: Fix the APIC address registration

The device tree APIC parser tries to force enable the local APIC when it is
not set in CPUID. apic_force_enable() registers the boot CPU apic on
success.

If that succeeds then dtb_lapic_setup() registers the local APIC again
eventually with a different address.

Rewrite the code so that it only registers it once.

Signed-off-by: Thomas Gleixner <tglx@...utronix.de>
---
 arch/x86/kernel/devicetree.c |   14 +++++---------
 1 file changed, 5 insertions(+), 9 deletions(-)

--- a/arch/x86/kernel/devicetree.c
+++ b/arch/x86/kernel/devicetree.c
@@ -157,19 +157,15 @@ static void __init dtb_lapic_setup(void)
 
 	/* Did the boot loader setup the local APIC ? */
 	if (!boot_cpu_has(X86_FEATURE_APIC)) {
+		/* Try force enabling, which registers the APIC address */
 		if (apic_force_enable(lapic_addr))
 			return;
-	}
-	smp_found_config = 1;
-	if (of_property_read_bool(dn, "intel,virtual-wire-mode")) {
-		pr_info("Virtual Wire compatibility mode.\n");
-		pic_mode = 0;
 	} else {
-		pr_info("IMCR and PIC compatibility mode.\n");
-		pic_mode = 1;
+		register_lapic_address(lapic_addr);
 	}
-
-	register_lapic_address(lapic_addr);
+	smp_found_config = 1;
+	pic_mode = !of_property_read_bool(dn, "intel,virtual-wire-mode");
+	pr_info("%s compatibility mode.\n", pic_mode ? "IMCR and PIC" : "Virtual Wire");
 }
 
 #endif /* CONFIG_X86_LOCAL_APIC */