Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67;
Date:   Mon, 27 Nov 2017 15:35:09 -0800
From:   tip-bot for Chunyu Hu <tipbot@zytor.com>
Message-ID: <tip-d632044a53571267034f430a5433f048ff8168da@git.kernel.org>
Cc:     linux-kernel@vger.kernel.org, tglx@linutronix.de, hpa@zytor.com,
        chuhu@redhat.com, mingo@kernel.org
Reply-To: linux-kernel@vger.kernel.org, tglx@linutronix.de,
          chuhu@redhat.com, mingo@kernel.org, hpa@zytor.com
In-Reply-To: <1511792499-4073-1-git-send-email-chuhu@redhat.com>
References: <1511792499-4073-1-git-send-email-chuhu@redhat.com>
To:     linux-tip-commits@vger.kernel.org
Subject: [tip:x86/urgent] x86/idt: Load idt early in start_secondary
Git-Commit-ID: d632044a53571267034f430a5433f048ff8168da
Robot-ID: <tip-bot.git.kernel.org>
Robot-Unsubscribe: Contact <mailto:hpa@kernel.org> to get blacklisted from
 these emails
MIME-Version: 1.0
Content-Transfer-Encoding: 8bit
Content-Type: text/plain; charset=UTF-8
Content-Disposition: inline
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk

Commit-ID:  d632044a53571267034f430a5433f048ff8168da
Gitweb:     https://git.kernel.org/tip/d632044a53571267034f430a5433f048ff8168da
Author:     Chunyu Hu <chuhu@redhat.com>
AuthorDate: Mon, 27 Nov 2017 22:21:39 +0800
Committer:  Thomas Gleixner <tglx@linutronix.de>
CommitDate: Tue, 28 Nov 2017 00:28:56 +0100

x86/idt: Load idt early in start_secondary

On a secondary, idt is first loaded in cpu_init() with load_current_idt(),
i.e. no exceptions can be handled before that point.

The conversion of WARN() to use UD requires the IDT being loaded earlier as
any warning between start_secondary() and load_curren_idt() in cpu_init()
will result in an unhandled @UD exception and therefore fail the bringup of
the CPU.

Install the IDT handlers right in start_secondary() before calling cpu_init().

[ tglx: Massaged changelog ]

Signed-off-by: Chunyu Hu <chuhu@redhat.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: peterz@infradead.org
Cc: bp@alien8.de
Cc: rostedt@goodmis.org
Cc: luto@kernel.org
Link: https://lkml.kernel.org/r/1511792499-4073-1-git-send-email-chuhu@redhat.com

---
 arch/x86/kernel/smpboot.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/x86/kernel/smpboot.c b/arch/x86/kernel/smpboot.c
index 3d01df7..05a97d5 100644
--- a/arch/x86/kernel/smpboot.c
+++ b/arch/x86/kernel/smpboot.c
@@ -237,7 +237,7 @@ static void notrace start_secondary(void *unused)
 	load_cr3(swapper_pg_dir);
 	__flush_tlb_all();
 #endif
-
+	load_current_idt();
 	cpu_init();
 	x86_cpuinit.early_percpu_clock_init();
 	preempt_disable();

From 1583729029264008975@xxx Sat Nov 11 00:54:59 +0000 2017
X-GM-THRID: 1583067906559816766
X-Gmail-Labels: Inbox,Category Forums,HistoricalUnread