From: Hsin-Yi Wang hsinyi@chromium.org
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: Hsin-Yi Wang hsinyi@chromium.org Reviewed-by: Stephen Boyd swboyd@chromium.org Signed-off-by: Will Deacon will@kernel.org --- arch/arm64/kernel/machine_kexec_file.c | 18 +++++++++++++++++- 1 file changed, 17 insertions(+), 1 deletion(-)
diff --git a/arch/arm64/kernel/machine_kexec_file.c b/arch/arm64/kernel/machine_kexec_file.c index 58871333737a..81b5baad97aa 100644 --- a/arch/arm64/kernel/machine_kexec_file.c +++ b/arch/arm64/kernel/machine_kexec_file.c @@ -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 @@ static int setup_dtb(struct kimage *image, }
/* - * 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