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authorJon DeVree <nuxi@vault24.org>2019-04-19 23:35:16 -0400
committerTheodore Ts'o <tytso@mit.edu>2019-04-19 23:35:16 -0400
commitfe6f1a6a8eedc1aa538fee0baa612b6a59639cf8 (patch)
tree96806087df69b7aaff6fe1a9606fba97d2bb3489 /drivers/char
parentd55535232c3dbde9a523a9d10d68670f5fe5dec3 (diff)
downloadlinux-fe6f1a6a8eedc1aa538fee0baa612b6a59639cf8.tar.bz2
random: fix CRNG initialization when random.trust_cpu=1
When the system boots with random.trust_cpu=1 it doesn't initialize the per-NUMA CRNGs because it skips the rest of the CRNG startup code. This means that the code from 1e7f583af67b ("random: make /dev/urandom scalable for silly userspace programs") is not used when random.trust_cpu=1. crash> dmesg | grep random: [ 0.000000] random: get_random_bytes called from start_kernel+0x94/0x530 with crng_init=0 [ 0.314029] random: crng done (trusting CPU's manufacturer) crash> print crng_node_pool $6 = (struct crng_state **) 0x0 After adding the missing call to numa_crng_init() the per-NUMA CRNGs are initialized again: crash> dmesg | grep random: [ 0.000000] random: get_random_bytes called from start_kernel+0x94/0x530 with crng_init=0 [ 0.314031] random: crng done (trusting CPU's manufacturer) crash> print crng_node_pool $1 = (struct crng_state **) 0xffff9a915f4014a0 The call to invalidate_batched_entropy() was also missing. This is important for architectures like PPC and S390 which only have the arch_get_random_seed_* functions. Fixes: 39a8883a2b98 ("random: add a config option to trust the CPU's hwrng") Signed-off-by: Jon DeVree <nuxi@vault24.org> Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Diffstat (limited to 'drivers/char')
-rw-r--r--drivers/char/random.c5
1 files changed, 4 insertions, 1 deletions
diff --git a/drivers/char/random.c b/drivers/char/random.c
index 8757ed493b11..f3ef5db4ca94 100644
--- a/drivers/char/random.c
+++ b/drivers/char/random.c
@@ -772,6 +772,7 @@ static struct crng_state **crng_node_pool __read_mostly;
#endif
static void invalidate_batched_entropy(void);
+static void numa_crng_init(void);
static bool trust_cpu __ro_after_init = IS_ENABLED(CONFIG_RANDOM_TRUST_CPU);
static int __init parse_trust_cpu(char *arg)
@@ -800,7 +801,9 @@ static void crng_initialize(struct crng_state *crng)
}
crng->state[i] ^= rv;
}
- if (trust_cpu && arch_init) {
+ if (trust_cpu && arch_init && crng == &primary_crng) {
+ invalidate_batched_entropy();
+ numa_crng_init();
crng_init = 2;
pr_notice("random: crng done (trusting CPU's manufacturer)\n");
}