Commit 7f591fa7 authored by Hsin-Yi Wang's avatar Hsin-Yi Wang Committed by Will Deacon
Browse files

arm64: kexec_file: add rng-seed support 



Adding "rng-seed" to dtb. It's fine to add this property if original
fdt doesn't contain it. Since original seed will be wiped after
read, so use a default size 128 bytes here.

Signed-off-by: default avatarHsin-Yi Wang <hsinyi@chromium.org>
Reviewed-by: default avatarStephen Boyd <swboyd@chromium.org>
Signed-off-by: default avatarWill Deacon <will@kernel.org>
parent 428826f5

arch/arm64/kernel/machine_kexec_file.c

+17 −1
Original line number Diff line number Diff line
@@ -27,6 +27,8 @@ 
#define FDT_PROP_INITRD_END	"linux,initrd-end"

#define FDT_PROP_BOOTARGS	"bootargs"

#define FDT_PROP_KASLR_SEED	"kaslr-seed"

#define FDT_PROP_RNG_SEED	"rng-seed"

#define RNG_SEED_SIZE		128



const struct kexec_file_ops * const kexec_file_loaders[] = {

	&kexec_image_ops,
@@ -102,6 +104,19 @@ static int setup_dtb(struct kimage *image, 
				FDT_PROP_KASLR_SEED);

	}



	/* add rng-seed */

	if (rng_is_initialized()) {

		u8 rng_seed[RNG_SEED_SIZE];

		get_random_bytes(rng_seed, RNG_SEED_SIZE);

		ret = fdt_setprop(dtb, off, FDT_PROP_RNG_SEED, rng_seed,

				RNG_SEED_SIZE);

		if (ret)

			goto out;

	} else {

		pr_notice("RNG is not initialised: omitting \"%s\" property\n",

				FDT_PROP_RNG_SEED);

	}



out:

	if (ret)

		return (ret == -FDT_ERR_NOSPACE) ? -ENOMEM : -EINVAL;
@@ -110,7 +125,8 @@ out: 
}



/*

 * More space needed so that we can add initrd, bootargs and kaslr-seed.

 * More space needed so that we can add initrd, bootargs, kaslr-seed, and

 * rng-seed.

 */

#define DTB_EXTRA_SPACE 0x1000

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