[PATCH -rc7][resend] kthread: Silence bogus section mismatch warning

[PATCH -rc7][resend] kthread: Silence bogus section mismatch warning

[Satyam Sharma]

This:

WARNING: kernel/built-in.o(.text+0x16910): Section mismatch:
reference to .init.text: (between 'kthreadd' and 'init_waitqueue_head')

comes because kernel/kthread.c:kthreadd() is not __init but calls
kthreadd_setup() which is __init. But this is ok, because kthreadd_setup()
is only ever called at init time, and then kthreadd() proceeds into its
"for (;;)" loop. We could mark kthreadd __init_refok, but kthreadd_setup()
with just one callsite and 4 lines in it (it's been that small since
10ab825bdef8df51) doesn't need to be a separate function at all -- so let's
just move those four lines at beginning of kthreadd() itself.

Signed-off-by: Satyam Sharma <ssatyam@cse.iitk.ac.in>

---

First discussed in http://lkml.org/lkml/2007/6/26/274,
and I keep getting this with:

|$ ld -V
|GNU ld version 2.17
|  Supported emulations:
|   elf_i386
|   i386linux
|   elf_x86_64

|$ gcc -v
|Reading specs from /usr/lib/gcc/i386-pc-linux-gnu/3.4.4/specs
|Configured with: /var/tmp/portage/gcc-3.4.4-r1/work/gcc-3.4.4/configure
|--prefix=/usr --bindir=/usr/i386-pc-linux-gnu/gcc-bin/3.4.4
|--with-gxx-include-dir=/usr/lib/gcc/i386-pc-linux-gnu/3.4.4/include/g++-v3
|--host=i386-pc-linux-gnu --build=i386-pc-linux-gnu --disable-altivec
|--enable-nls --without-included-gettext --with-system-zlib --disable-checking
|--disable-werror --disable-libunwind-exceptions --disable-multilib
|--disable-libgcj --enable-languages=c,c++,f77 --enable-shared
|--enable-threads=posix --enable-__cxa_atexit --enable-clocale=gnu
|Thread model: posix
|gcc version 3.4.4 (Gentoo 3.4.4-r1, ssp-3.4.4-1.0, pie-8.7.8)

 kernel/kthread.c |   12 ++----------
 1 file changed, 2 insertions(+), 10 deletions(-)

---

diff -ruNp a/kernel/kthread.c b/kernel/kthread.c
--- a/kernel/kthread.c	2007-06-26 06:33:08.000000000 +0530
+++ b/kernel/kthread.c	2007-06-27 02:57:46.000000000 +0530
@@ -214,23 +214,15 @@ int kthread_stop(struct task_struct *k)
 }
 EXPORT_SYMBOL(kthread_stop);
 
-
-static __init void kthreadd_setup(void)
+int kthreadd(void *unused)
 {
 	struct task_struct *tsk = current;
 
+	/* Setup a clean context for our children to inherit. */
 	set_task_comm(tsk, "kthreadd");
-
 	ignore_signals(tsk);
-
 	set_user_nice(tsk, -5);
 	set_cpus_allowed(tsk, CPU_MASK_ALL);
-}
-
-int kthreadd(void *unused)
-{
-	/* Setup a clean context for our children to inherit. */
-	kthreadd_setup();
 
 	current->flags |= PF_NOFREEZE;
 

Re: [PATCH -rc7][resend] kthread: Silence bogus section mismatch warning

[Randy Dunlap]

On Sat, 07 Jul 2007 22:17:22 +0530 Satyam Sharma wrote:

> This:
> 
> WARNING: kernel/built-in.o(.text+0x16910): Section mismatch:
> reference to .init.text: (between 'kthreadd' and 'init_waitqueue_head')
> 
> comes because kernel/kthread.c:kthreadd() is not __init but calls
> kthreadd_setup() which is __init. But this is ok, because kthreadd_setup()
> is only ever called at init time, and then kthreadd() proceeds into its
> "for (;;)" loop. We could mark kthreadd __init_refok, but kthreadd_setup()
> with just one callsite and 4 lines in it (it's been that small since
> 10ab825bdef8df51) doesn't need to be a separate function at all -- so let's
> just move those four lines at beginning of kthreadd() itself.
> 
> Signed-off-by: Satyam Sharma <ssatyam@cse.iitk.ac.in>

Acked-by: Randy Dunlap <randy.dunlap@oracle.com>

> ---
> 
> First discussed in http://lkml.org/lkml/2007/6/26/274,
> and I keep getting this with:
> ...
> 
>  kernel/kthread.c |   12 ++----------
>  1 file changed, 2 insertions(+), 10 deletions(-)
> 
> ---
> 
> diff -ruNp a/kernel/kthread.c b/kernel/kthread.c
> --- a/kernel/kthread.c	2007-06-26 06:33:08.000000000 +0530
> +++ b/kernel/kthread.c	2007-06-27 02:57:46.000000000 +0530
> @@ -214,23 +214,15 @@ int kthread_stop(struct task_struct *k)
>  }
>  EXPORT_SYMBOL(kthread_stop);
>  
> -
> -static __init void kthreadd_setup(void)
> +int kthreadd(void *unused)
>  {
>  	struct task_struct *tsk = current;
>  
> +	/* Setup a clean context for our children to inherit. */
>  	set_task_comm(tsk, "kthreadd");
> -
>  	ignore_signals(tsk);
> -
>  	set_user_nice(tsk, -5);
>  	set_cpus_allowed(tsk, CPU_MASK_ALL);
> -}
> -
> -int kthreadd(void *unused)
> -{
> -	/* Setup a clean context for our children to inherit. */
> -	kthreadd_setup();
>  
>  	current->flags |= PF_NOFREEZE;
>  


---
~Randy
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