Re: [PATCH v6 1/4] kexec: clean up arch_kexec_kernel_verify_sig

[Coiby Xu]

On Thu, Apr 14, 2022 at 11:44:25AM +0800, Baoquan He wrote:
> On 04/14/22 at 09:43am, Coiby Xu wrote:
> > Currently there is no arch-specific implementation of
> > arch_kexec_kernel_verify_sig. Even if we want to add an implementation
> > for an architecture in the future, we can simply use "(struct
> > kexec_file_ops*)->verify_sig". So clean it up.
> >
> > Suggested-by: Eric W. Biederman <ebiederm@xxxxxxxxxxxx>
> > Cc: stable@xxxxxxxxxx
>
> It should be not worth noticing stable kernel that a clean up patch need
> be back ported.

Thanks for the suggestion! For the 2nd and 3rd patch, I'll add prerequisite
info,

Cc: stable@xxxxxxxxxx # 34d5960af253: kexec: clean up arch_kexec_kernel_verify_sig

and 

Cc: stable@xxxxxxxxxx # 34d5960af253: kexec: clean up arch_kexec_kernel_verify_sig
Cc: stable@xxxxxxxxxx # 83b7bb2d49ae: kexec, KEYS: make the code in bzImage64_verify_sig generic

respectively.

> Otherwise this looks good to me,
>
> Acked-by: Baoquan He <bhe@xxxxxxxxxx>

Thanks for reviewing the patch!

> > Reviewed-by: Michal Suchanek <msuchanek@xxxxxxx>
> > Signed-off-by: Coiby Xu <coxu@xxxxxxxxxx>
> > ---
> >  include/linux/kexec.h |  4 ----
> >  kernel/kexec_file.c   | 34 +++++++++++++---------------------
> >  2 files changed, 13 insertions(+), 25 deletions(-)
> >
> > diff --git a/include/linux/kexec.h b/include/linux/kexec.h
> > index 58d1b58a971e..413235c6c797 100644
> > --- a/include/linux/kexec.h
> > +++ b/include/linux/kexec.h
> > @@ -202,10 +202,6 @@ int arch_kexec_apply_relocations(struct purgatory_info *pi,
> >  				 const Elf_Shdr *relsec,
> >  				 const Elf_Shdr *symtab);
> >  int arch_kimage_file_post_load_cleanup(struct kimage *image);
> > -#ifdef CONFIG_KEXEC_SIG
> > -int arch_kexec_kernel_verify_sig(struct kimage *image, void *buf,
> > -				 unsigned long buf_len);
> > -#endif
> >  int arch_kexec_locate_mem_hole(struct kexec_buf *kbuf);
> >
> >  extern int kexec_add_buffer(struct kexec_buf *kbuf);
> > diff --git a/kernel/kexec_file.c b/kernel/kexec_file.c
> > index 8347fc158d2b..3720435807eb 100644
> > --- a/kernel/kexec_file.c
> > +++ b/kernel/kexec_file.c
> > @@ -89,25 +89,6 @@ int __weak arch_kimage_file_post_load_cleanup(struct kimage *image)
> >  	return kexec_image_post_load_cleanup_default(image);
> >  }
> >
> > -#ifdef CONFIG_KEXEC_SIG
> > -static int kexec_image_verify_sig_default(struct kimage *image, void *buf,
> > -					  unsigned long buf_len)
> > -{
> > -	if (!image->fops || !image->fops->verify_sig) {
> > -		pr_debug("kernel loader does not support signature verification.\n");
> > -		return -EKEYREJECTED;
> > -	}
> > -
> > -	return image->fops->verify_sig(buf, buf_len);
> > -}
> > -
> > -int __weak arch_kexec_kernel_verify_sig(struct kimage *image, void *buf,
> > -					unsigned long buf_len)
> > -{
> > -	return kexec_image_verify_sig_default(image, buf, buf_len);
> > -}
> > -#endif
> > -
> >  /*
> >   * arch_kexec_apply_relocations_add - apply relocations of type RELA
> >   * @pi:		Purgatory to be relocated.
> > @@ -184,13 +165,24 @@ void kimage_file_post_load_cleanup(struct kimage *image)
> >  }
> >
> >  #ifdef CONFIG_KEXEC_SIG
> > +static int kexec_image_verify_sig(struct kimage *image, void *buf,
> > +		unsigned long buf_len)
> > +{
> > +	if (!image->fops || !image->fops->verify_sig) {
> > +		pr_debug("kernel loader does not support signature verification.\n");
> > +		return -EKEYREJECTED;
> > +	}
> > +
> > +	return image->fops->verify_sig(buf, buf_len);
> > +}
> > +
> >  static int
> >  kimage_validate_signature(struct kimage *image)
> >  {
> >  	int ret;
> >
> > -	ret = arch_kexec_kernel_verify_sig(image, image->kernel_buf,
> > -					   image->kernel_buf_len);
> > +	ret = kexec_image_verify_sig(image, image->kernel_buf,
> > +			image->kernel_buf_len);
> >  	if (ret) {
> >
> >  		if (IS_ENABLED(CONFIG_KEXEC_SIG_FORCE)) {
> > --
> > 2.34.1

--
Best regards,
Coiby