Re: [PATCH 11/11] kexec_file: Move purgatories sha256 to common code

From: Dave Young
Date: Thu Mar 08 2018 - 23:44:09 EST


On 02/26/18 at 04:16pm, Philipp Rudo wrote:
> The code to verify the new kernels sha digest are applicable for all
> architectures. Move it to common code.
>
> Signed-off-by: Philipp Rudo <prudo@xxxxxxxxxxxxxxxxxx>
> ---
> arch/x86/purgatory/Makefile | 3 +++
> arch/x86/purgatory/purgatory.c | 2 +-
> {arch/x86/purgatory => include/linux}/sha256.h | 10 +++++++++-
> {arch/x86/purgatory => lib}/sha256.c | 4 ++--
> 4 files changed, 15 insertions(+), 4 deletions(-)
> rename {arch/x86/purgatory => include/linux}/sha256.h (63%)
> rename {arch/x86/purgatory => lib}/sha256.c (99%)
>
> diff --git a/arch/x86/purgatory/Makefile b/arch/x86/purgatory/Makefile
> index 2f15a2ac4209..414eed6b5065 100644
> --- a/arch/x86/purgatory/Makefile
> +++ b/arch/x86/purgatory/Makefile
> @@ -6,6 +6,9 @@ purgatory-y := purgatory.o stack.o setup-x86_$(BITS).o sha256.o entry64.o string
> targets += $(purgatory-y)
> PURGATORY_OBJS = $(addprefix $(obj)/,$(purgatory-y))
>
> +$(obj)/sha256.o: $(srctree)/lib/sha256.c
> + $(call if_changed_rule,cc_o_c)
> +
> LDFLAGS_purgatory.ro := -e purgatory_start -r --no-undefined -nostdlib -z nodefaultlib
> targets += purgatory.ro
>
> diff --git a/arch/x86/purgatory/purgatory.c b/arch/x86/purgatory/purgatory.c
> index 470edad96bb9..025c34ac0d84 100644
> --- a/arch/x86/purgatory/purgatory.c
> +++ b/arch/x86/purgatory/purgatory.c
> @@ -11,9 +11,9 @@
> */
>
> #include <linux/bug.h>
> +#include <linux/sha256.h>
> #include <asm/purgatory.h>
>
> -#include "sha256.h"
> #include "../boot/string.h"
>
> unsigned long purgatory_backup_dest __section(.kexec-purgatory);
> diff --git a/arch/x86/purgatory/sha256.h b/include/linux/sha256.h
> similarity index 63%
> rename from arch/x86/purgatory/sha256.h
> rename to include/linux/sha256.h
> index 2867d9825a57..43a20ac33688 100644
> --- a/arch/x86/purgatory/sha256.h
> +++ b/include/linux/sha256.h
> @@ -13,9 +13,17 @@
> #include <linux/types.h>
> #include <crypto/sha.h>
>
> +/* Stand-alone implementation of the SHA256 algorithm. It is designed to
> + * have as little dependencies as possible so it can be used in the
> + * kexec_file purgatory. In other cases you should use the implementation in
> + * crypto/.
> + *
> + * For details see lib/sha256.c
> + */

should move to use preferred comment format:
/*
* Stand-alone ...
* ...
*/

> +
> extern int sha256_init(struct sha256_state *sctx);
> extern int sha256_update(struct sha256_state *sctx, const u8 *input,
> - unsigned int length);
> + unsigned int length);
> extern int sha256_final(struct sha256_state *sctx, u8 *hash);
>
> #endif /* SHA256_H */
> diff --git a/arch/x86/purgatory/sha256.c b/lib/sha256.c
> similarity index 99%
> rename from arch/x86/purgatory/sha256.c
> rename to lib/sha256.c
> index 548ca675a14a..4400c832e2aa 100644
> --- a/arch/x86/purgatory/sha256.c
> +++ b/lib/sha256.c
> @@ -16,9 +16,9 @@
> */
>
> #include <linux/bitops.h>
> +#include <linux/sha256.h>
> +#include <linux/string.h>
> #include <asm/byteorder.h>
> -#include "sha256.h"
> -#include "../boot/string.h"

Hmm, I'm not sure if moving to linux/string.h will have some side
effects..

>
> static inline u32 Ch(u32 x, u32 y, u32 z)
> {
> --
> 2.13.5
>

Thanks
Dave