Le 25/06/2022 à 17:38, Jason A. Donenfeld a écrit :
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.
Signed-off-by: Jason A. Donenfeld <Jason@xxxxxxxxx>
---
arch/m68k/include/uapi/asm/bootinfo-virt.h | 1 +
arch/m68k/virt/config.c | 4 ++++
2 files changed, 5 insertions(+)
diff --git a/arch/m68k/include/uapi/asm/bootinfo-virt.h b/arch/m68k/include/uapi/asm/bootinfo-virt.h
index e4db7e2213ab..7c3044acdf4a 100644
--- a/arch/m68k/include/uapi/asm/bootinfo-virt.h
+++ b/arch/m68k/include/uapi/asm/bootinfo-virt.h
@@ -12,6 +12,7 @@
#define BI_VIRT_GF_TTY_BASE 0x8003
#define BI_VIRT_VIRTIO_BASE 0x8004
#define BI_VIRT_CTRL_BASE 0x8005
+#define BI_VIRT_RNG_SEED 0x8006
#define VIRT_BOOTI_VERSION MK_BI_VERSION(2, 0)
diff --git a/arch/m68k/virt/config.c b/arch/m68k/virt/config.c
index 632ba200ad42..ad71af8273ec 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 +93,9 @@ 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:
+ add_bootloader_randomness(data + 4, be32_to_cpup(data));
In fact, why don't you use the record->size to get the size of the buffer?
It seems useless to encode twice the length of the buffer, the second time on a 32bit while the
length cannot exceed a 16bit value.
Thanks,
Laurent
