In order to pass fresh entropy to kexec'd kernels, use BI_VIRT_RNG_SEED
for passing a seed, with the same semantics that kexec-tools currently
uses for i386's setup_data.
Cc: Geert Uytterhoeven <geert@xxxxxxxxxxxxxx>
Signed-off-by: Jason A. Donenfeld <Jason@xxxxxxxxx>
---
Geert - I don't have a toolchain for testing this. Could you verify it
works, if you have a chance? -Jason
kexec/arch/m68k/bootinfo.c | 22 ++++++++++++++++++++++
kexec/arch/m68k/bootinfo.h | 6 ++++++
kexec/arch/m68k/kexec-elf-m68k.c | 1 +
3 files changed, 29 insertions(+)
diff --git a/kexec/arch/m68k/bootinfo.c b/kexec/arch/m68k/bootinfo.c
index 18bf226..74e65a0 100644
--- a/kexec/arch/m68k/bootinfo.c
+++ b/kexec/arch/m68k/bootinfo.c
@@ -135,40 +135,45 @@ void bootinfo_print(void)
size = bi->size;
switch (tag) {
case BI_MACHTYPE:
printf("BI_MACHTYPE: 0x%08x\n", bi->machtype);
break;
case BI_MEMCHUNK:
printf("BI_MEMCHUNK: 0x%08x bytes at 0x%08x\n",
bi->mem_info.size, bi->mem_info.addr);
break;
case BI_RAMDISK:
printf("BI_RAMDISK: 0x%08x bytes at 0x%08x\n",
bi->mem_info.size, bi->mem_info.addr);
break;
case BI_COMMAND_LINE:
printf("BI_COMMAND_LINE: %s\n", bi->string);
break;
+ case BI_VIRT_RNG_SEED:
+ /* These are secret, so never print them to the console */
+ printf("BI_VIRT_RNG_SEED: 0x%08x bytes\n", be16_to_cpu(bi->bytes.len));
+ break;
+
default:
printf("BI tag 0x%04x size %u\n", tag, size);
break;
}
bi = bi_next(bi, size);
}
}
int bootinfo_get_memory_ranges(struct memory_range **range)
{
struct memory_range *ranges;
unsigned int i;
struct bi_rec *bi;
ranges = xmalloc(num_memchunks * sizeof(struct memory_range));
for (i = 0, bi = NULL;
i < num_memchunks && (bi = bi_find(bi, BI_MEMCHUNK)); i++) {
ranges[i].start = bi->mem_info.addr;
ranges[i].end = bi->mem_info.addr + bi->mem_info.size - 1;
ranges[i].type = RANGE_RAM;
@@ -195,40 +200,57 @@ void bootinfo_set_cmdline(const char *cmdline)
memcpy(bi->string, cmdline, size);
}
void bootinfo_set_ramdisk(unsigned long ramdisk_addr,
unsigned long ramdisk_size)
{
struct bi_rec *bi;
/* Remove existing ramdisk records */
bi_remove(BI_RAMDISK);
if (!ramdisk_size)
return;
/* Add new ramdisk record */
bi = bi_add(BI_RAMDISK, sizeof(bi->mem_info));
bi->mem_info.addr = ramdisk_addr;
bi->mem_info.size = ramdisk_size;
}
+void bootinfo_add_rng_seed(void)
+{
+ struct bi_rec *bi;
+ enum { RNG_SEED_LEN = 32 };
+
+ /* Remove existing rng seed records */
+ bi_remove(BI_VIRT_RNG_SEED);
+
+ /* Add new rng seed record */
+ bi = bi_add(BI_VIRT_RNG_SEED, sizeof(bi->bytes) + RNG_SEED_LEN);
+ if (getrandom(bi->bytes.data, RNG_SEED_LEN, GRND_NONBLOCK) != RNG_SEED_LEN) {
+ bi_remove(BI_VIRT_RNG_SEED);
+ return;
+ }
+ bi->bytes.len = cpu_to_be16(RNG_SEED_LEN);
+}
+
/*
* Check the bootinfo version in the kernel image
* All failures are non-fatal, as kexec may be used to load
* non-Linux images
*/
void bootinfo_check_bootversion(const struct kexec_info *info)
{
struct bi_rec *bi;
const struct bootversion *bv;
uint16_t major, minor;
unsigned int i;
bv = info->segment[0].buf;
if (bv->magic != BOOTINFOV_MAGIC) {
printf("WARNING: No bootversion in kernel image\n");
return;
}
diff --git a/kexec/arch/m68k/bootinfo.h b/kexec/arch/m68k/bootinfo.h
index b6f453d..6dff2ad 100644
--- a/kexec/arch/m68k/bootinfo.h
+++ b/kexec/arch/m68k/bootinfo.h
@@ -1,43 +1,49 @@
#include <asm/bootinfo.h>
+#include <asm/bootinfo-virt.h>
#define DEFAULT_BOOTINFO_FILE "/proc/bootinfo"
#define MAX_BOOTINFO_SIZE 1536
/*
* Convenience overlay of several struct bi_record variants
*/
struct bi_rec {
__be16 tag;
__be16 size;
union {
__be32 data[0];
/* shorthands for the types we use */
__be32 machtype;
struct {
__be32 addr;
__be32 size;
} mem_info;
char string[0];
+ struct {
+ __be16 len;
+ u8 data[0];
+ } bytes;
};
};
/*
* We only support the "new" tagged bootinfo (v2)
*/
#define SUPPORTED_BOOTINFO_VERSION 2
extern const char *bootinfo_file;
extern void bootinfo_load(void);
extern void bootinfo_print(void);
extern int bootinfo_get_memory_ranges(struct memory_range **range);
extern void bootinfo_set_cmdline(const char *cmdline);
extern void bootinfo_set_ramdisk(unsigned long ramdisk_addr,
unsigned long ramdisk_size);
+extern void bootinfo_add_rng_seed(void);
extern void bootinfo_check_bootversion(const struct kexec_info *info);
extern void add_bootinfo(struct kexec_info *info, unsigned long addr);
diff --git a/kexec/arch/m68k/kexec-elf-m68k.c b/kexec/arch/m68k/kexec-elf-m68k.c
index 8d00eb9..a2bf7ee 100644
--- a/kexec/arch/m68k/kexec-elf-m68k.c
+++ b/kexec/arch/m68k/kexec-elf-m68k.c
@@ -145,38 +145,39 @@ int elf_m68k_load(int argc, char **argv, const char *buf, off_t len,
bootinfo_addr = segment_end(info, info->nr_segments - 1) + 1;
/* Load ramdisk */
if (ramdisk_file) {
void *ramdisk = slurp_decompress_file(ramdisk_file,
&ramdisk_size);
/* Store ramdisk at top of first memory chunk */
ramdisk_addr = _ALIGN_DOWN(info->memory_range[0].end -
ramdisk_size + 1,
PAGE_SIZE);
if (!buf)
die("Ramdisk load failed\n");
add_buffer(info, ramdisk, ramdisk_size, ramdisk_size,
PAGE_SIZE, ramdisk_addr, info->memory_range[0].end,
1);
}
/* Update and add bootinfo */
bootinfo_set_cmdline(cmdline);
bootinfo_set_ramdisk(ramdisk_addr, ramdisk_size);
+ bootinfo_add_rng_seed();
if (kexec_debug)
bootinfo_print();
add_bootinfo(info, bootinfo_addr);
/*
* Check if the kernel (and bootinfo) exceed 4 MiB, as current kernels
* don't support that.
* As the segments are still unsorted, the bootinfo is located in the
* last segment.
*/
if (segment_end(info, info->nr_segments - 1) >= virt_to_phys(4 MiB - 1))
printf("WARNING: Kernel is larger than 4 MiB\n");
/* Check struct bootversion at start of kernel */
bootinfo_check_bootversion(info);
return 0;
}
--
2.37.3
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