From c59974aea43fd292a0784dbf7b3d7347e2caf4e9 Mon Sep 17 00:00:00 2001 From: Theodore Ts'o Date: Sat, 21 Sep 2013 19:42:41 -0400 Subject: [PATCH] random: optimize the entropy_store structure Use smaller types to slightly shrink the size of the entropy store structure. Signed-off-by: "Theodore Ts'o" --- drivers/char/random.c | 16 ++++++++-------- 1 file changed, 8 insertions(+), 8 deletions(-) diff --git a/drivers/char/random.c b/drivers/char/random.c index 89eb5a8dec82..b8809d4ae186 100644 --- a/drivers/char/random.c +++ b/drivers/char/random.c @@ -436,16 +436,16 @@ struct entropy_store { __u32 *pool; const char *name; struct entropy_store *pull; - int limit; /* read-write data: */ spinlock_t lock; - unsigned add_ptr; - unsigned input_rotate; + unsigned short add_ptr; + unsigned short input_rotate; int entropy_count; int entropy_total; unsigned int initialized:1; - bool last_data_init; + unsigned int limit:1; + unsigned int last_data_init:1; __u8 last_data[EXTRACT_SIZE]; }; @@ -513,7 +513,7 @@ static void _mix_pool_bytes(struct entropy_store *r, const void *in, /* mix one byte at a time to simplify size handling and churn faster */ while (nbytes--) { - w = rol32(*bytes++, input_rotate & 31); + w = rol32(*bytes++, input_rotate); i = (i - 1) & wordmask; /* XOR in the various taps */ @@ -533,7 +533,7 @@ static void _mix_pool_bytes(struct entropy_store *r, const void *in, * rotation, so that successive passes spread the * input bits across the pool evenly. */ - input_rotate += i ? 7 : 14; + input_rotate = (input_rotate + (i ? 7 : 14)) & 31; } ACCESS_ONCE(r->input_rotate) = input_rotate; @@ -1049,7 +1049,7 @@ static ssize_t extract_entropy(struct entropy_store *r, void *buf, if (fips_enabled) { spin_lock_irqsave(&r->lock, flags); if (!r->last_data_init) { - r->last_data_init = true; + r->last_data_init = 1; spin_unlock_irqrestore(&r->lock, flags); trace_extract_entropy(r->name, EXTRACT_SIZE, ENTROPY_BITS(r), _RET_IP_); @@ -1189,7 +1189,7 @@ static void init_std_data(struct entropy_store *r) r->entropy_count = 0; r->entropy_total = 0; - r->last_data_init = false; + r->last_data_init = 0; mix_pool_bytes(r, &now, sizeof(now), NULL); for (i = r->poolinfo->poolbytes; i > 0; i -= sizeof(rv)) { if (!arch_get_random_long(&rv)) -- 2.39.5