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Subject[PATCH 2/7] x86/boot/compressed/64: Reload CS in startup_32
Date
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 --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
--
2.30.0
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