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| author | Theodore Ts'o <tytso@mit.edu> | 2013-11-03 00:15:05 -0400 |
|---|---|---|
| committer | Theodore Ts'o <tytso@mit.edu> | 2013-11-03 18:18:47 -0500 |
| commit | 40db23e5337d99fda05ee6cd18034b516f8f123d (patch) | |
| tree | 3620424cec3d8df5ec5455335620e65b37a94909 /drivers/char | |
| parent | f80bbd8b92987f55f26691cd53785c4a54622eb0 (diff) | |
| download | linux-40db23e5337d99fda05ee6cd18034b516f8f123d.tar.bz2 | |
random: make add_timer_randomness() fill the nonblocking pool first
Change add_timer_randomness() so that it directs incoming entropy to
the nonblocking pool first if it hasn't been fully initialized yet.
This matches the strategy we use in add_interrupt_randomness(), which
allows us to push the randomness where we need it the most during when
the system is first booting up, so that get_random_bytes() and
/dev/urandom become safe to use as soon as possible.
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Diffstat (limited to 'drivers/char')
| -rw-r--r-- | drivers/char/random.c | 7 |
1 files changed, 4 insertions, 3 deletions
diff --git a/drivers/char/random.c b/drivers/char/random.c index f126bd2f69fe..62923138e77a 100644 --- a/drivers/char/random.c +++ b/drivers/char/random.c @@ -761,6 +761,7 @@ static struct timer_rand_state input_timer_state; */ static void add_timer_randomness(struct timer_rand_state *state, unsigned num) { + struct entropy_store *r; struct { long jiffies; unsigned cycles; @@ -773,7 +774,8 @@ static void add_timer_randomness(struct timer_rand_state *state, unsigned num) sample.jiffies = jiffies; sample.cycles = random_get_entropy(); sample.num = num; - mix_pool_bytes(&input_pool, &sample, sizeof(sample), NULL); + r = nonblocking_pool.initialized ? &input_pool : &nonblocking_pool; + mix_pool_bytes(r, &sample, sizeof(sample), NULL); /* * Calculate number of bits of randomness we probably added. @@ -807,8 +809,7 @@ static void add_timer_randomness(struct timer_rand_state *state, unsigned num) * Round down by 1 bit on general principles, * and limit entropy entimate to 12 bits. */ - credit_entropy_bits(&input_pool, - min_t(int, fls(delta>>1), 11)); + credit_entropy_bits(r, min_t(int, fls(delta>>1), 11)); } preempt_enable(); } |