linux-kernel - [PATCH v6 28/76] x86/idt: Move IDT to data segment

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Message-Id: <20200824085511.7553-29-joro@8bytes.org>
Date:   Mon, 24 Aug 2020 10:54:23 +0200
From:   Joerg Roedel <joro@...tes.org>
To:     x86@...nel.org
Cc:     Joerg Roedel <joro@...tes.org>, Joerg Roedel <jroedel@...e.de>,
        Kees Cook <keescook@...omium.org>, hpa@...or.com,
        Andy Lutomirski <luto@...nel.org>,
        Dave Hansen <dave.hansen@...ux.intel.com>,
        Peter Zijlstra <peterz@...radead.org>,
        Jiri Slaby <jslaby@...e.cz>,
        Dan Williams <dan.j.williams@...el.com>,
        Tom Lendacky <thomas.lendacky@....com>,
        Juergen Gross <jgross@...e.com>,
        David Rientjes <rientjes@...gle.com>,
        Cfir Cohen <cfir@...gle.com>,
        Erdem Aktas <erdemaktas@...gle.com>,
        Masami Hiramatsu <mhiramat@...nel.org>,
        Mike Stunes <mstunes@...are.com>,
        Sean Christopherson <sean.j.christopherson@...el.com>,
        Martin Radev <martin.b.radev@...il.com>,
        linux-kernel@...r.kernel.org, kvm@...r.kernel.org,
        virtualization@...ts.linux-foundation.org
Subject: [PATCH v6 28/76] x86/idt: Move IDT to data segment

From: Joerg Roedel <jroedel@...e.de>

With SEV-ES, exception handling is needed very early, even before the
kernel has cleared the bss segment. In order to prevent clearing the
currently used IDT, move the IDT to the data segment.

Signed-off-by: Joerg Roedel <jroedel@...e.de>
Reviewed-by: Kees Cook <keescook@...omium.org>
Link: https://lore.kernel.org/r/20200724160336.5435-28-joro@8bytes.org
---
 arch/x86/kernel/idt.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/x86/kernel/idt.c b/arch/x86/kernel/idt.c
index 7ecf9babf0cb..34fcc58b81b5 100644
--- a/arch/x86/kernel/idt.c
+++ b/arch/x86/kernel/idt.c
@@ -158,7 +158,7 @@ static const __initconst struct idt_data apic_idts[] = {
 };
 
 /* Must be page-aligned because the real IDT is used in the cpu entry area */
-static gate_desc idt_table[IDT_ENTRIES] __page_aligned_bss;
+static gate_desc idt_table[IDT_ENTRIES] __page_aligned_data;
 
 static struct desc_ptr idt_descr __ro_after_init = {
 	.size		= IDT_TABLE_SIZE - 1,
-- 
2.28.0