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authorLinus Torvalds <torvalds@linux-foundation.org>2012-12-20 05:23:37 +0100
committerLinus Torvalds <torvalds@linux-foundation.org>2012-12-20 05:23:37 +0100
commit7005cd39707ba59b5b1d3e70da2c448d3235eb3e (patch)
tree89ed68e2cfd68f038d58f86a0eb5fe7eea279103 /drivers/char
parentMerge tag 'xtensa-20121218' of git://github.com/czankel/xtensa-linux (diff)
parentrandom: Mix cputime from each thread that exits to the pool (diff)
downloadlinux-7005cd39707ba59b5b1d3e70da2c448d3235eb3e.tar.xz
linux-7005cd39707ba59b5b1d3e70da2c448d3235eb3e.zip
Merge tag 'random_for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/random
Pull random updates from Ted Ts'o: "A few /dev/random improvements for the v3.8 merge window." * tag 'random_for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/random: random: Mix cputime from each thread that exits to the pool random: prime last_data value per fips requirements random: fix debug format strings random: make it possible to enable debugging without rebuild
Diffstat (limited to 'drivers/char')
-rw-r--r--drivers/char/random.c40
1 files changed, 27 insertions, 13 deletions
diff --git a/drivers/char/random.c b/drivers/char/random.c
index b86eae9b77df..85e81ec1451e 100644
--- a/drivers/char/random.c
+++ b/drivers/char/random.c
@@ -399,7 +399,6 @@ static DECLARE_WAIT_QUEUE_HEAD(random_read_wait);
static DECLARE_WAIT_QUEUE_HEAD(random_write_wait);
static struct fasync_struct *fasync;
-#if 0
static bool debug;
module_param(debug, bool, 0644);
#define DEBUG_ENT(fmt, arg...) do { \
@@ -410,9 +409,6 @@ module_param(debug, bool, 0644);
blocking_pool.entropy_count,\
nonblocking_pool.entropy_count,\
## arg); } while (0)
-#else
-#define DEBUG_ENT(fmt, arg...) do {} while (0)
-#endif
/**********************************************************************
*
@@ -437,6 +433,7 @@ struct entropy_store {
int entropy_count;
int entropy_total;
unsigned int initialized:1;
+ bool last_data_init;
__u8 last_data[EXTRACT_SIZE];
};
@@ -829,7 +826,7 @@ static void xfer_secondary_pool(struct entropy_store *r, size_t nbytes)
bytes = min_t(int, bytes, sizeof(tmp));
DEBUG_ENT("going to reseed %s with %d bits "
- "(%d of %d requested)\n",
+ "(%zu of %d requested)\n",
r->name, bytes * 8, nbytes * 8, r->entropy_count);
bytes = extract_entropy(r->pull, tmp, bytes,
@@ -860,7 +857,7 @@ static size_t account(struct entropy_store *r, size_t nbytes, int min,
spin_lock_irqsave(&r->lock, flags);
BUG_ON(r->entropy_count > r->poolinfo->POOLBITS);
- DEBUG_ENT("trying to extract %d bits from %s\n",
+ DEBUG_ENT("trying to extract %zu bits from %s\n",
nbytes * 8, r->name);
/* Can we pull enough? */
@@ -882,7 +879,7 @@ static size_t account(struct entropy_store *r, size_t nbytes, int min,
}
}
- DEBUG_ENT("debiting %d entropy credits from %s%s\n",
+ DEBUG_ENT("debiting %zu entropy credits from %s%s\n",
nbytes * 8, r->name, r->limit ? "" : " (unlimited)");
spin_unlock_irqrestore(&r->lock, flags);
@@ -957,6 +954,10 @@ static ssize_t extract_entropy(struct entropy_store *r, void *buf,
ssize_t ret = 0, i;
__u8 tmp[EXTRACT_SIZE];
+ /* if last_data isn't primed, we need EXTRACT_SIZE extra bytes */
+ if (fips_enabled && !r->last_data_init)
+ nbytes += EXTRACT_SIZE;
+
trace_extract_entropy(r->name, nbytes, r->entropy_count, _RET_IP_);
xfer_secondary_pool(r, nbytes);
nbytes = account(r, nbytes, min, reserved);
@@ -967,6 +968,17 @@ static ssize_t extract_entropy(struct entropy_store *r, void *buf,
if (fips_enabled) {
unsigned long flags;
+
+ /* prime last_data value if need be, per fips 140-2 */
+ if (!r->last_data_init) {
+ spin_lock_irqsave(&r->lock, flags);
+ memcpy(r->last_data, tmp, EXTRACT_SIZE);
+ r->last_data_init = true;
+ nbytes -= EXTRACT_SIZE;
+ spin_unlock_irqrestore(&r->lock, flags);
+ extract_buf(r, tmp);
+ }
+
spin_lock_irqsave(&r->lock, flags);
if (!memcmp(tmp, r->last_data, EXTRACT_SIZE))
panic("Hardware RNG duplicated output!\n");
@@ -1086,6 +1098,7 @@ static void init_std_data(struct entropy_store *r)
r->entropy_count = 0;
r->entropy_total = 0;
+ r->last_data_init = false;
mix_pool_bytes(r, &now, sizeof(now), NULL);
for (i = r->poolinfo->POOLBYTES; i > 0; i -= sizeof(rv)) {
if (!arch_get_random_long(&rv))
@@ -1142,11 +1155,16 @@ random_read(struct file *file, char __user *buf, size_t nbytes, loff_t *ppos)
if (n > SEC_XFER_SIZE)
n = SEC_XFER_SIZE;
- DEBUG_ENT("reading %d bits\n", n*8);
+ DEBUG_ENT("reading %zu bits\n", n*8);
n = extract_entropy_user(&blocking_pool, buf, n);
- DEBUG_ENT("read got %d bits (%d still needed)\n",
+ if (n < 0) {
+ retval = n;
+ break;
+ }
+
+ DEBUG_ENT("read got %zd bits (%zd still needed)\n",
n*8, (nbytes-n)*8);
if (n == 0) {
@@ -1171,10 +1189,6 @@ random_read(struct file *file, char __user *buf, size_t nbytes, loff_t *ppos)
continue;
}
- if (n < 0) {
- retval = n;
- break;
- }
count += n;
buf += n;
nbytes -= n;