Re: [PATCH V2 2/2] kexec: split kexec_load syscall from kexec core code

[Dave Young <dyoung@redhat.com>]

On 07/21/15 at 09:03am, Vivek Goyal wrote:
> On Mon, Jul 20, 2015 at 04:37:15PM +0800, dyoung@redhat.com wrote:
> > Now there's two kexec load syscall, one is kexec_load another is
> > kexec_file_load, kexec_file_load has been splited as kernel/kexec_file.c.
> > In this patch I split kexec_load syscall code to kernel/kexec.c.
> 
> Hi Dave,
> 
> Nice work. Thanks for doing this. I have couple of minor comments.
> 
> - We might have to audit kernel/kexec_core.c. I think there are some
>   functions in there which are used by only old syscall and not the new
>   one. All that code should be in kernel/kexec.c. Only the code which is
>   shared between two syscalls should be in kernel/kexec_core.c.
>   
>   For example, I think kimage_alloc_init() is used by old syscall only.
>   New syscall uses kimage_file_alloc_init().

You are right, actually two functions
copy_user_segment_list and kimage_alloc_init are used by kexec.c only

Will move them to kexec.c from kexec_core.c, it works well during my testing

> 
> [..]
> > --- linux.orig/include/linux/kexec.h
> > +++ linux/include/linux/kexec.h
> > @@ -16,7 +16,7 @@
> >  
> >  #include <uapi/linux/kexec.h>
> >  
> > -#ifdef CONFIG_KEXEC
> > +#ifdef CONFIG_KEXEC_CORE
> >  #include <linux/list.h>
> >  #include <linux/linkage.h>
> >  #include <linux/compat.h>
> > @@ -318,12 +318,18 @@ int crash_shrink_memory(unsigned long ne
> >  size_t crash_get_memory_size(void);
> >  void crash_free_reserved_phys_range(unsigned long begin, unsigned long end);
> >  
> > -#else /* !CONFIG_KEXEC */
> > +#ifdef CONFIG_KEXEC
> > +int kimage_alloc_init(struct kimage **rimage, unsigned long entry,
> > +			     unsigned long nr_segments,
> > +			     struct kexec_segment __user *segments,
> > +			     unsigned long flags);
> > +#endif
> 
> I am wondering why this needs to be in kexec.h. Who needs this? Even if
> somebody needs this, this should probably be outside of KEXEC_CORE.

It was added here in 1st version before adding kexec_internal.h, later
I moved most of them to kexec_internal.h, but yes it is not used by
any file other than kexec.c, will drop this chunk.

Thanks a lot
Dave