Subject: Re: next-0703: build failure in x86/entry_64.S

From: Ingo Molnar <[email-masked]>
Date: Thu, 3 Jul 2008 15:31:32 +0200

* Alexander Beregalov <[email-masked]> wrote:

> Hi
> 
>   AS      arch/x86/kernel/entry_64.o
> arch/x86/kernel/entry_64.S: Assembler messages:
> arch/x86/kernel/entry_64.S:1200: Error: invalid character '_' in mnemonic
> arch/x86/kernel/entry_64.S:1204: Error: invalid character '_' in mnemonic
> arch/x86/kernel/entry_64.S:1208: Error: invalid character '_' in mnemonic
> arch/x86/kernel/entry_64.S:1212: Error: invalid character '_' in mnemonic

hm, cannot reproduce it here with linux-next-0702.

but ... this looks quite similar to an issue triggered by the 
tip/x86/xen-64bit topic (and fixed by the patch below) - but that's not 
in linux-next yet.

	Ingo

------------->
commit 6d2a6e57be1582b017a39f52385adf49d7cc4b0f
Author: Jeremy Fitzhardinge <[email-masked]>
Date:   Fri Jun 27 12:04:03 2008 -0700

    x86_64: fix non-paravirt compilation
    
    Make sure SWAPGS and PARAVIRT_ADJUST_EXCEPTION_FRAME are properly
    defined when CONFIG_PARAVIRT is off.
    
    Fixes Ingo's build failure:
    arch/x86/kernel/entry_64.S: Assembler messages:
    arch/x86/kernel/entry_64.S:1201: Error: invalid character '_' in mnemonic
    arch/x86/kernel/entry_64.S:1205: Error: invalid character '_' in mnemonic
    arch/x86/kernel/entry_64.S:1209: Error: invalid character '_' in mnemonic
    arch/x86/kernel/entry_64.S:1213: Error: invalid character '_' in mnemonic
    
    Signed-off-by: Jeremy Fitzhardinge <[email-masked]>
    Cc: Nick Piggin <[email-masked]>
    Cc: Mark McLoughlin <[email-masked]>
    Cc: xen-devel <[email-masked]>
    Cc: Eduardo Habkost <[email-masked]>
    Cc: Vegard Nossum <[email-masked]>
    Cc: Stephen Tweedie <[email-masked]>
    Signed-off-by: Ingo Molnar <[email-masked]>

diff --git a/include/asm-x86/irqflags.h b/include/asm-x86/irqflags.h
index 484c74f..754bb3a 100644
--- a/include/asm-x86/irqflags.h
+++ b/include/asm-x86/irqflags.h
@@ -167,7 +167,20 @@ static inline unsigned long __raw_local_irq_save(void)
 #define INTERRUPT_RETURN_NMI_SAFE	NATIVE_INTERRUPT_RETURN_NMI_SAFE
 
 #ifdef CONFIG_X86_64
+#define SWAPGS	swapgs
+/*
+ * Currently paravirt can't handle swapgs nicely when we
+ * don't have a stack we can rely on (such as a user space
+ * stack).  So we either find a way around these or just fault
+ * and emulate if a guest tries to call swapgs directly.
+ *
+ * Either way, this is a good way to document that we don't
+ * have a reliable stack. x86_64 only.
+ */
 #define SWAPGS_UNSAFE_STACK	swapgs
+
+#define PARAVIRT_ADJUST_EXCEPTION_FRAME	/*  */
+
 #define INTERRUPT_RETURN	iretq
 #define USERGS_SYSRET64				\
 	swapgs;					\
@@ -233,15 +246,6 @@ static inline void trace_hardirqs_fixup(void)
 #else
 
 #ifdef CONFIG_X86_64
-/*
- * Currently paravirt can't handle swapgs nicely when we
- * don't have a stack we can rely on (such as a user space
- * stack).  So we either find a way around these or just fault
- * and emulate if a guest tries to call swapgs directly.
- *
- * Either way, this is a good way to document that we don't
- * have a reliable stack. x86_64 only.
- */
 #define ARCH_TRACE_IRQS_ON		call trace_hardirqs_on_thunk
 #define ARCH_TRACE_IRQS_OFF		call trace_hardirqs_off_thunk
 #define ARCH_LOCKDEP_SYS_EXIT		call lockdep_sys_exit_thunk
diff --git a/include/asm-x86/processor.h b/include/asm-x86/processor.h
index a935c70..6f5e195 100644
--- a/include/asm-x86/processor.h
+++ b/include/asm-x86/processor.h
@@ -535,9 +535,6 @@ static inline void load_sp0(struct tss_struct *tss,
 }
 
 #define set_iopl_mask native_set_iopl_mask
-#define SWAPGS	swapgs
-
-#define PARAVIRT_ADJUST_EXCEPTION_FRAME	/*  */
 #endif /* CONFIG_PARAVIRT */
 
 /*