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| author | Jon DeVree <nuxi@vault24.org> | 2019-04-19 23:35:16 -0400 |
|---|---|---|
| committer | Theodore Ts'o <tytso@mit.edu> | 2019-04-19 23:35:16 -0400 |
| commit | fe6f1a6a8eedc1aa538fee0baa612b6a59639cf8 (patch) | |
| tree | 96806087df69b7aaff6fe1a9606fba97d2bb3489 | |
| parent | d55535232c3dbde9a523a9d10d68670f5fe5dec3 (diff) | |
| download | linux-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>
| -rw-r--r-- | drivers/char/random.c | 5 |
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"); } |