Re: [PATCH -mm] ftrace : Fix section mismatch warning.

["Rakib Mullick" <rakib.mullick@gmail.com>]

On 10/22/08, Ingo Molnar <mingo@elte.hu> wrote:
>
> * Ingo Molnar <mingo@elte.hu> wrote:
>
>>
>> * Rakib Mullick <rakib.mullick@gmail.com> wrote:
>>
>> > WARNING: arch/x86/kernel/built-in.o(.text+0x11b41): Section mismatch
>> > in reference from the variable ftrace_test_p6nop to the function
>> > .init.text:ftrace_dyn_arch_init()
>> > The function ftrace_test_p6nop() references
>> > the function __init ftrace_dyn_arch_init().
>> > This is often because ftrace_test_p6nop lacks a __init
>> > annotation or the annotation of ftrace_dyn_arch_init is wrong.
>> >
>> > WARNING: arch/x86/kernel/built-in.o(.text+0x11b4b): Section mismatch
>> > in reference from the variable ftrace_test_nop5 to the function
>> > .init.text:ftrace_dyn_arch_init()
>> > The function ftrace_test_nop5() references
>> > the function __init ftrace_dyn_arch_init().
>> > This is often because ftrace_test_nop5 lacks a __init
>> > annotation or the annotation of ftrace_dyn_arch_init is wrong.
>> >
>> > This patch fixes the above warnings. Introduced by
>> > 'linux-next.patch'(2.6.27-rc5-mm1-broken-out).
>> > Thanks.
>> >
>> > Signed-off-by: Md.Rakib H. Mullick(rakib.mullick@gmail.com)
>>
>> applied to tip/tracing/urgent, thanks!
>
> actually, this patch is wrong: the problem highlighted in that warning
> is that ftrace_test_p6nop is non-__init while ftrace_dyn_arch_init() is
> __init. So the proper solution is to mark ftrace_test_p6nop init as
> well. (it's an assembly label so thus slightly more complex than usual,
> but doable.)

Does the following solves the problem?
Thanks.

--- linux-2.6-orig/arch/x86/kernel/ftrace.c	2008-10-24 16:35:48.000000000 +0600
+++ linux-2.6/arch/x86/kernel/ftrace.c	2008-10-24 16:40:09.000000000 +0600
@@ -129,7 +129,7 @@ int __init ftrace_dyn_arch_init(void *da
 	asm volatile (
 		"jmp ftrace_test_jmp\n"
 		/* This code needs to stay around */
-		".section .text, \"ax\"\n"
+		".section .text.init, \"ax\"\n"
 		"ftrace_test_jmp:"
 		"jmp ftrace_test_p6nop\n"
 		"nop\n"

>
> 	Ingo
>