linux-kernel - [PATCH v5 27/75] x86/idt: Move IDT to data segment

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:   Fri, 24 Jul 2020 18:02:48 +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 v5 27/75] 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>
---
 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,
-- 
2.27.0