From: Jason A. Donenfeld <Jason@xxxxxxxxx>
commit dc63a086daee92c63e392e4e7cd7ed61f3693026 upstream.
This is useful on !virt platforms for kexec, so change things from
BI_VIRT_RNG_SEED to be BI_RNG_SEED, and simply remove BI_VIRT_RNG_SEED
because it only ever lasted one release, and nothing is broken by not
having it. At the same time, keep a comment noting that it's been
removed, so that ID isn't reused. In addition, we previously documented
2-byte alignment, but 4-byte alignment is actually necessary, so update
that comment.
Suggested-by: Geert Uytterhoeven <geert@xxxxxxxxxxxxxx>
Fixes: a1ee38ab1a75 ("m68k: virt: Use RNG seed from bootinfo block")
Signed-off-by: Jason A. Donenfeld <Jason@xxxxxxxxx>
Link: https://lore.kernel.org/r/20220927130835.1629806-2-Jason@xxxxxxxxx
Signed-off-by: Geert Uytterhoeven <geert@xxxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
arch/m68k/include/uapi/asm/bootinfo-virt.h | 9 ++-------
arch/m68k/include/uapi/asm/bootinfo.h | 7 +++++++
arch/m68k/kernel/setup_mm.c | 12 ++++++++++++
arch/m68k/virt/config.c | 11 -----------
4 files changed, 21 insertions(+), 18 deletions(-)
--- a/arch/m68k/include/uapi/asm/bootinfo-virt.h
+++ b/arch/m68k/include/uapi/asm/bootinfo-virt.h
@@ -13,13 +13,8 @@
#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
+/* No longer used -- replaced with BI_RNG_SEED -- but don't reuse this index:
+ * #define BI_VIRT_RNG_SEED 0x8006 */
#define VIRT_BOOTI_VERSION MK_BI_VERSION(2, 0)
--- a/arch/m68k/include/uapi/asm/bootinfo.h
+++ b/arch/m68k/include/uapi/asm/bootinfo.h
@@ -64,6 +64,13 @@ struct mem_info {
/* (struct mem_info) */
#define BI_COMMAND_LINE 0x0007 /* kernel command line parameters */
/* (string) */
+/*
+ * A random seed used to initialize the RNG. Record format:
+ *
+ * - length [ 2 bytes, 16-bit big endian ]
+ * - seed data [ `length` bytes, padded to preserve 4-byte struct alignment ]
+ */
+#define BI_RNG_SEED 0x0008
/*
--- a/arch/m68k/kernel/setup_mm.c
+++ b/arch/m68k/kernel/setup_mm.c
@@ -25,6 +25,7 @@
#include <linux/module.h>
#include <linux/nvram.h>
#include <linux/initrd.h>
+#include <linux/random.h>
#include <asm/bootinfo.h>
#include <asm/byteorder.h>
@@ -151,6 +152,17 @@ static void __init m68k_parse_bootinfo(c
sizeof(m68k_command_line));
break;
+ case BI_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:
if (MACH_IS_AMIGA)
unknown = amiga_parse_bootinfo(record);
--- a/arch/m68k/virt/config.c
+++ b/arch/m68k/virt/config.c
@@ -2,7 +2,6 @@
#include <linux/reboot.h>
#include <linux/serial_core.h>
-#include <linux/random.h>
#include <clocksource/timer-goldfish.h>
#include <asm/bootinfo.h>
@@ -93,16 +92,6 @@ int __init virt_parse_bootinfo(const str
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;
