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authorJason A. Donenfeld <Jason@zx2c4.com>2022-06-26 13:15:09 +0200
committerGeert Uytterhoeven <geert@linux-m68k.org>2022-07-06 14:07:04 +0200
commita1ee38ab1a75ee20e4aad232894db3ea45d3ce4f (patch)
tree2e79e381bdcfcb9e35d53e1b1357a3b53ea7eee8 /arch/m68k/virt
parent6f08e51cdbe08370ad0a8580d0d6ea6ffdfed46d (diff)
downloadlinux-a1ee38ab1a75ee20e4aad232894db3ea45d3ce4f.tar.bz2
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/virt')
-rw-r--r--arch/m68k/virt/config.c11
1 files changed, 11 insertions, 0 deletions
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;