Messages in this thread Patch in this message | | | From | Joerg Roedel <> | Subject | [PATCH v3 3/8] x86/boot/compressed/64: Reload CS in startup_32 | Date | Fri, 12 Mar 2021 13:38:19 +0100 |
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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 -- 2.30.1
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