From: "Jason A. Donenfeld" <Jason@zx2c4.com>
To: tsbogend@alpha.franken.de, linux-mips@vger.kernel.org,
linux-kernel@vger.kernel.org
Cc: "Jason A. Donenfeld" <Jason@zx2c4.com>
Subject: [PATCH] mips: allow firmware to pass RNG seed to kernel
Date: Fri, 30 Sep 2022 16:01:38 +0200 [thread overview]
Message-ID: <20220930140138.575751-1-Jason@zx2c4.com> (raw)
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>
---
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 2ca156a5b231..39c79f67c7a3 100644
--- a/arch/mips/kernel/setup.c
+++ b/arch/mips/kernel/setup.c
@@ -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];
--
2.37.3
next reply other threads:[~2022-09-30 14:02 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-09-30 14:01 Jason A. Donenfeld [this message]
2022-10-01 16:09 ` [PATCH] mips: allow firmware to pass RNG seed to kernel Thomas Bogendoerfer
2022-10-03 22:07 ` Philippe Mathieu-Daudé
2022-10-03 22:30 ` Jason A. Donenfeld
2022-10-06 11:28 ` Philippe Mathieu-Daudé
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