mips: allow firmware to pass RNG seed to kernel

Nearly all other firmware environments have some way of passing a RNG
seed to initialize the RNG: DTB's rng-seed, EFI's RNG protocol, m68k's
bootinfo block, x86's setup_data, and so forth. This adds something
similar for MIPS, which will allow various firmware environments,
bootloaders, and hypervisors to pass an RNG seed to initialize the
kernel's RNG.

Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
This commit is contained in:
Jason A. Donenfeld 2022-09-30 16:01:38 +02:00 committed by Thomas Bogendoerfer
parent 8e6ec6ce02
commit 056a68cea0

View file

@ -42,6 +42,7 @@
#include <asm/setup.h>
#include <asm/smp-ops.h>
#include <asm/prom.h>
#include <asm/fw/fw.h>
#ifdef CONFIG_MIPS_ELF_APPENDED_DTB
char __section(".appended_dtb") __appended_dtb[0x100000];
@ -756,6 +757,24 @@ static void __init prefill_possible_map(void)
static inline void prefill_possible_map(void) {}
#endif
static void __init setup_rng_seed(void)
{
char *rng_seed_hex = fw_getenv("rngseed");
u8 rng_seed[512];
size_t len;
if (!rng_seed_hex)
return;
len = min(sizeof(rng_seed), strlen(rng_seed_hex) / 2);
if (hex2bin(rng_seed, rng_seed_hex, len))
return;
add_bootloader_randomness(rng_seed, len);
memzero_explicit(rng_seed, len);
memzero_explicit(rng_seed_hex, len * 2);
}
void __init setup_arch(char **cmdline_p)
{
cpu_probe();
@ -786,6 +805,8 @@ void __init setup_arch(char **cmdline_p)
paging_init();
memblock_dump_all();
setup_rng_seed();
}
unsigned long kernelsp[NR_CPUS];