diff options
| author | Jason A. Donenfeld <Jason@zx2c4.com> | 2022-06-26 13:15:09 +0200 |
|---|---|---|
| committer | Geert Uytterhoeven <geert@linux-m68k.org> | 2022-07-06 14:07:04 +0200 |
| commit | a1ee38ab1a75ee20e4aad232894db3ea45d3ce4f (patch) | |
| tree | 2e79e381bdcfcb9e35d53e1b1357a3b53ea7eee8 /arch/m68k | |
| parent | 6f08e51cdbe08370ad0a8580d0d6ea6ffdfed46d (diff) | |
m68k: virt: Use RNG seed from bootinfo block
Other virt VMs can pass RNG seeds via the "rng-seed" device tree
property or via UEFI, but m68k doesn't have either. Instead it has its
own bootinfo protocol. So this commit adds support for receiving a RNG
seed from it, which will be used at the earliest possible time in boot,
just like device tree.
Reviewed-by: Laurent Vivier <laurent@vivier.eu>
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
Link: https://lore.kernel.org/r/20220626111509.330159-1-Jason@zx2c4.com
Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
Diffstat (limited to 'arch/m68k')
| -rw-r--r-- | arch/m68k/include/uapi/asm/bootinfo-virt.h | 8 | ||||
| -rw-r--r-- | arch/m68k/virt/config.c | 11 |
2 files changed, 19 insertions, 0 deletions
diff --git a/arch/m68k/include/uapi/asm/bootinfo-virt.h b/arch/m68k/include/uapi/asm/bootinfo-virt.h index e4db7e2213ab..b091ee9b06e0 100644 --- a/arch/m68k/include/uapi/asm/bootinfo-virt.h +++ b/arch/m68k/include/uapi/asm/bootinfo-virt.h @@ -13,6 +13,14 @@ #define BI_VIRT_VIRTIO_BASE 0x8004 #define BI_VIRT_CTRL_BASE 0x8005 +/* + * A random seed used to initialize the RNG. Record format: + * + * - length [ 2 bytes, 16-bit big endian ] + * - seed data [ `length` bytes, padded to preserve 2-byte alignment ] + */ +#define BI_VIRT_RNG_SEED 0x8006 + #define VIRT_BOOTI_VERSION MK_BI_VERSION(2, 0) #endif /* _UAPI_ASM_M68K_BOOTINFO_MAC_H */ diff --git a/arch/m68k/virt/config.c b/arch/m68k/virt/config.c index 632ba200ad42..4ab22946ff68 100644 --- a/arch/m68k/virt/config.c +++ b/arch/m68k/virt/config.c @@ -2,6 +2,7 @@ #include <linux/reboot.h> #include <linux/serial_core.h> +#include <linux/random.h> #include <clocksource/timer-goldfish.h> #include <asm/bootinfo.h> @@ -92,6 +93,16 @@ int __init virt_parse_bootinfo(const struct bi_record *record) data += 4; virt_bi_data.virtio.irq = be32_to_cpup(data); break; + case BI_VIRT_RNG_SEED: { + u16 len = be16_to_cpup(data); + add_bootloader_randomness(data + 2, len); + /* + * Zero the data to preserve forward secrecy, and zero the + * length to prevent kexec from using it. + */ + memzero_explicit((void *)data, len + 2); + break; + } default: unknown = 1; break; |