From 32a748d0897223af00ae3ec19d47a91060f0d22a Mon Sep 17 00:00:00 2001 From: "Jason A. Donenfeld" Date: Fri, 30 Sep 2022 16:01:38 +0200 Subject: [PATCH] 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 Signed-off-by: Thomas Bogendoerfer --- arch/mips/kernel/setup.c | 21 +++++++++++++++++++++ 1 file changed, 21 insertions(+) diff --git a/arch/mips/kernel/setup.c b/arch/mips/kernel/setup.c index 2ca156a5b2319..39c79f67c7a33 100644 --- a/arch/mips/kernel/setup.c +++ b/arch/mips/kernel/setup.c @@ -42,6 +42,7 @@ #include #include #include +#include #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]; -- 2.39.5