diff mbox series

[v2,2/7] x86/boot/compressed/64: Reload CS in startup_32

Message ID 20210310084325.12966-3-joro@8bytes.org (mailing list archive)
State New, archived
Headers show
Series x86/seves: Support 32-bit boot path and other updates | expand

Commit Message

Joerg Roedel March 10, 2021, 8:43 a.m. UTC 
From: Joerg Roedel <jroedel@suse.de>

Exception handling in the startup_32 boot path requires the CS
selector to be correctly set up. Reload it from the current GDT.

Signed-off-by: Joerg Roedel <jroedel@suse.de>
---
 arch/x86/boot/compressed/head_64.S | 9 ++++++++-
 1 file changed, 8 insertions(+), 1 deletion(-)
diff mbox series

Patch

diff --git a/arch/x86/boot/compressed/head_64.S b/arch/x86/boot/compressed/head_64.S
index e94874f4bbc1..c59c80ca546d 100644
--- a/arch/x86/boot/compressed/head_64.S
+++ b/arch/x86/boot/compressed/head_64.S
@@ -107,9 +107,16 @@  SYM_FUNC_START(startup_32)
 	movl	%eax, %gs
 	movl	%eax, %ss
 
-/* setup a stack and make sure cpu supports long mode. */
+	/* Setup a stack and load CS from current GDT */
 	leal	rva(boot_stack_end)(%ebp), %esp
 
+	pushl	$__KERNEL32_CS
+	leal	rva(1f)(%ebp), %eax
+	pushl	%eax
+	lretl
+1:
+
+	/* Make sure cpu supports long mode. */
 	call	verify_cpu
 	testl	%eax, %eax
 	jnz	.Lno_longmode