From ac630dd98a47b60b27d716758d5f4276cb974662 Mon Sep 17 00:00:00 2001 From: Linus Torvalds Date: Fri, 22 Feb 2013 13:09:51 -0800 Subject: x86-64: don't set the early IDT to point directly to 'early_idt_handler' The code requires the use of the proper per-exception-vector stub functions (set up as the early_idt_handlers[] array - note the 's') that make sure to set up the error vector number. This is true regardless of whether CONFIG_EARLY_PRINTK is set or not. Why? The stack offset for the comparison of __KERNEL_CS won't be right otherwise, nor will the new check (from commit 8170e6bed465: "x86, 64bit: Use a #PF handler to materialize early mappings on demand") for the page fault exception vector. Acked-by: H. Peter Anvin Signed-off-by: Linus Torvalds --- arch/x86/kernel/head_64.S | 2 ++ 1 file changed, 2 insertions(+) (limited to 'arch/x86/kernel/head_64.S') diff --git a/arch/x86/kernel/head_64.S b/arch/x86/kernel/head_64.S index d94f6d6..b7de3b2 100644 --- a/arch/x86/kernel/head_64.S +++ b/arch/x86/kernel/head_64.S @@ -336,6 +336,7 @@ early_idt_handlers: i = i + 1 .endr +/* This is global to keep gas from relaxing the jumps */ ENTRY(early_idt_handler) cld @@ -404,6 +405,7 @@ ENTRY(early_idt_handler) addq $16,%rsp # drop vector number and error code decl early_recursion_flag(%rip) INTERRUPT_RETURN +ENDPROC(early_idt_handler) __INITDATA -- cgit v1.1