[v4,27/75] x86/idt: Move IDT to data segment

Commit Message

Joerg Roedel July 14, 2020, 12:08 p.m. UTC

From: Joerg Roedel <[e-mail]>

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 <[e-mail]>
---
 arch/x86/kernel/idt.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

Comments

Kees Cook July 15, 2020, 1:25 a.m. UTC | #1

On Tue, Jul 14, 2020 at 02:08:29PM +0200, Joerg Roedel wrote:
> From: Joerg Roedel <[e-mail]>
> 
> 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 <[e-mail]>

Reviewed-by: Kees Cook <[e-mail]>

Patch

diff --git a/arch/x86/kernel/idt.c b/arch/x86/kernel/idt.c
index 0db21206f2f3..b920f2352df5 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;
 
 struct desc_ptr idt_descr __ro_after_init = {
 	.size		= IDT_TABLE_SIZE - 1,