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author | Jon DeVree <nuxi@vault24.org> | 2019-04-20 06:35:16 +0300 |
---|---|---|
committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2019-05-31 16:43:29 +0300 |
commit | 6f9c63bc3bfa95a82a5c8fa017ce898d47cbfa06 (patch) | |
tree | 16cbfc8e7666e95a3e086a19aaf9e44ce878ba6b /drivers/char | |
parent | ee079354fba85bda54b9c64f662b8cd16260fdf8 (diff) | |
download | linux-6f9c63bc3bfa95a82a5c8fa017ce898d47cbfa06.tar.xz |
random: fix CRNG initialization when random.trust_cpu=1
[ Upstream commit fe6f1a6a8eedc1aa538fee0baa612b6a59639cf8 ]
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>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Diffstat (limited to 'drivers/char')
-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 38c6d1af6d1c..d4d45ccfeefc 100644 --- a/drivers/char/random.c +++ b/drivers/char/random.c @@ -777,6 +777,7 @@ 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) @@ -805,7 +806,9 @@ 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"); } |