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authorThomas Gleixner <tglx@linutronix.de>2017-03-17 20:34:30 +0100
committerThomas Gleixner <tglx@linutronix.de>2017-03-17 20:34:30 +0100
commit79a21d572cf66968a2272fdf9711f835518256d9 (patch)
tree5fe3e4692fb8375faf8e1aeea1c2eae38c342250 /drivers/char/random.c
parentd1eb98143c56f24fef125f5bbed49ae0b52fb7d6 (diff)
parent822f5845f710e57d7e2df1fd1ee00d6e19d334fe (diff)
downloadtalos-op-linux-79a21d572cf66968a2272fdf9711f835518256d9.tar.gz
talos-op-linux-79a21d572cf66968a2272fdf9711f835518256d9.zip
Merge tag 'efi-urgent' of git://git.kernel.org/pub/scm/linux/kernel/git/efi/efi into efi/urgent
Pull a single UEFI fix from Ard: - Reduce the severity of the notice that appears when the ESRT table points to memory that is not covered by the memory map. It is scaring our users and interfering with their nice splash screens. Note that the ESRT may still be perfectly usable, and is currently (to my knowledge) not widely used to begin with.
Diffstat (limited to 'drivers/char/random.c')
-rw-r--r--drivers/char/random.c129
1 files changed, 50 insertions, 79 deletions
diff --git a/drivers/char/random.c b/drivers/char/random.c
index 1ef26403bcc8..0ab024918907 100644
--- a/drivers/char/random.c
+++ b/drivers/char/random.c
@@ -313,13 +313,6 @@ static int random_read_wakeup_bits = 64;
static int random_write_wakeup_bits = 28 * OUTPUT_POOL_WORDS;
/*
- * The minimum number of seconds between urandom pool reseeding. We
- * do this to limit the amount of entropy that can be drained from the
- * input pool even if there are heavy demands on /dev/urandom.
- */
-static int random_min_urandom_seed = 60;
-
-/*
* Originally, we used a primitive polynomial of degree .poolwords
* over GF(2). The taps for various sizes are defined below. They
* were chosen to be evenly spaced except for the last tap, which is 1
@@ -409,7 +402,6 @@ static struct poolinfo {
*/
static DECLARE_WAIT_QUEUE_HEAD(random_read_wait);
static DECLARE_WAIT_QUEUE_HEAD(random_write_wait);
-static DECLARE_WAIT_QUEUE_HEAD(urandom_init_wait);
static struct fasync_struct *fasync;
static DEFINE_SPINLOCK(random_ready_list_lock);
@@ -467,7 +459,6 @@ struct entropy_store {
int entropy_count;
int entropy_total;
unsigned int initialized:1;
- unsigned int limit:1;
unsigned int last_data_init:1;
__u8 last_data[EXTRACT_SIZE];
};
@@ -485,7 +476,6 @@ static __u32 blocking_pool_data[OUTPUT_POOL_WORDS] __latent_entropy;
static struct entropy_store input_pool = {
.poolinfo = &poolinfo_table[0],
.name = "input",
- .limit = 1,
.lock = __SPIN_LOCK_UNLOCKED(input_pool.lock),
.pool = input_pool_data
};
@@ -493,7 +483,6 @@ static struct entropy_store input_pool = {
static struct entropy_store blocking_pool = {
.poolinfo = &poolinfo_table[1],
.name = "blocking",
- .limit = 1,
.pull = &input_pool,
.lock = __SPIN_LOCK_UNLOCKED(blocking_pool.lock),
.pool = blocking_pool_data,
@@ -855,13 +844,6 @@ static void crng_reseed(struct crng_state *crng, struct entropy_store *r)
spin_unlock_irqrestore(&primary_crng.lock, flags);
}
-static inline void maybe_reseed_primary_crng(void)
-{
- if (crng_init > 2 &&
- time_after(jiffies, primary_crng.init_time + CRNG_RESEED_INTERVAL))
- crng_reseed(&primary_crng, &input_pool);
-}
-
static inline void crng_wait_ready(void)
{
wait_event_interruptible(crng_init_wait, crng_ready());
@@ -1220,15 +1202,6 @@ static void xfer_secondary_pool(struct entropy_store *r, size_t nbytes)
r->entropy_count > r->poolinfo->poolfracbits)
return;
- if (r->limit == 0 && random_min_urandom_seed) {
- unsigned long now = jiffies;
-
- if (time_before(now,
- r->last_pulled + random_min_urandom_seed * HZ))
- return;
- r->last_pulled = now;
- }
-
_xfer_secondary_pool(r, nbytes);
}
@@ -1236,8 +1209,6 @@ static void _xfer_secondary_pool(struct entropy_store *r, size_t nbytes)
{
__u32 tmp[OUTPUT_POOL_WORDS];
- /* For /dev/random's pool, always leave two wakeups' worth */
- int rsvd_bytes = r->limit ? 0 : random_read_wakeup_bits / 4;
int bytes = nbytes;
/* pull at least as much as a wakeup */
@@ -1248,7 +1219,7 @@ static void _xfer_secondary_pool(struct entropy_store *r, size_t nbytes)
trace_xfer_secondary_pool(r->name, bytes * 8, nbytes * 8,
ENTROPY_BITS(r), ENTROPY_BITS(r->pull));
bytes = extract_entropy(r->pull, tmp, bytes,
- random_read_wakeup_bits / 8, rsvd_bytes);
+ random_read_wakeup_bits / 8, 0);
mix_pool_bytes(r, tmp, bytes);
credit_entropy_bits(r, bytes*8);
}
@@ -1276,7 +1247,7 @@ static void push_to_pool(struct work_struct *work)
static size_t account(struct entropy_store *r, size_t nbytes, int min,
int reserved)
{
- int entropy_count, orig;
+ int entropy_count, orig, have_bytes;
size_t ibytes, nfrac;
BUG_ON(r->entropy_count > r->poolinfo->poolfracbits);
@@ -1285,14 +1256,12 @@ static size_t account(struct entropy_store *r, size_t nbytes, int min,
retry:
entropy_count = orig = ACCESS_ONCE(r->entropy_count);
ibytes = nbytes;
- /* If limited, never pull more than available */
- if (r->limit) {
- int have_bytes = entropy_count >> (ENTROPY_SHIFT + 3);
+ /* never pull more than available */
+ have_bytes = entropy_count >> (ENTROPY_SHIFT + 3);
- if ((have_bytes -= reserved) < 0)
- have_bytes = 0;
- ibytes = min_t(size_t, ibytes, have_bytes);
- }
+ if ((have_bytes -= reserved) < 0)
+ have_bytes = 0;
+ ibytes = min_t(size_t, ibytes, have_bytes);
if (ibytes < min)
ibytes = 0;
@@ -1912,6 +1881,7 @@ SYSCALL_DEFINE3(getrandom, char __user *, buf, size_t, count,
static int min_read_thresh = 8, min_write_thresh;
static int max_read_thresh = OUTPUT_POOL_WORDS * 32;
static int max_write_thresh = INPUT_POOL_WORDS * 32;
+static int random_min_urandom_seed = 60;
static char sysctl_bootid[16];
/*
@@ -2042,63 +2012,64 @@ struct ctl_table random_table[] = {
};
#endif /* CONFIG_SYSCTL */
-static u32 random_int_secret[MD5_MESSAGE_BYTES / 4] ____cacheline_aligned;
-
-int random_int_secret_init(void)
-{
- get_random_bytes(random_int_secret, sizeof(random_int_secret));
- return 0;
-}
-
-static DEFINE_PER_CPU(__u32 [MD5_DIGEST_WORDS], get_random_int_hash)
- __aligned(sizeof(unsigned long));
+struct batched_entropy {
+ union {
+ u64 entropy_u64[CHACHA20_BLOCK_SIZE / sizeof(u64)];
+ u32 entropy_u32[CHACHA20_BLOCK_SIZE / sizeof(u32)];
+ };
+ unsigned int position;
+};
/*
- * Get a random word for internal kernel use only. Similar to urandom but
- * with the goal of minimal entropy pool depletion. As a result, the random
- * value is not cryptographically secure but for several uses the cost of
- * depleting entropy is too high
+ * Get a random word for internal kernel use only. The quality of the random
+ * number is either as good as RDRAND or as good as /dev/urandom, with the
+ * goal of being quite fast and not depleting entropy.
*/
-unsigned int get_random_int(void)
+static DEFINE_PER_CPU(struct batched_entropy, batched_entropy_u64);
+u64 get_random_u64(void)
{
- __u32 *hash;
- unsigned int ret;
+ u64 ret;
+ struct batched_entropy *batch;
- if (arch_get_random_int(&ret))
+#if BITS_PER_LONG == 64
+ if (arch_get_random_long((unsigned long *)&ret))
return ret;
+#else
+ if (arch_get_random_long((unsigned long *)&ret) &&
+ arch_get_random_long((unsigned long *)&ret + 1))
+ return ret;
+#endif
- hash = get_cpu_var(get_random_int_hash);
-
- hash[0] += current->pid + jiffies + random_get_entropy();
- md5_transform(hash, random_int_secret);
- ret = hash[0];
- put_cpu_var(get_random_int_hash);
-
+ batch = &get_cpu_var(batched_entropy_u64);
+ if (batch->position % ARRAY_SIZE(batch->entropy_u64) == 0) {
+ extract_crng((u8 *)batch->entropy_u64);
+ batch->position = 0;
+ }
+ ret = batch->entropy_u64[batch->position++];
+ put_cpu_var(batched_entropy_u64);
return ret;
}
-EXPORT_SYMBOL(get_random_int);
+EXPORT_SYMBOL(get_random_u64);
-/*
- * Same as get_random_int(), but returns unsigned long.
- */
-unsigned long get_random_long(void)
+static DEFINE_PER_CPU(struct batched_entropy, batched_entropy_u32);
+u32 get_random_u32(void)
{
- __u32 *hash;
- unsigned long ret;
+ u32 ret;
+ struct batched_entropy *batch;
- if (arch_get_random_long(&ret))
+ if (arch_get_random_int(&ret))
return ret;
- hash = get_cpu_var(get_random_int_hash);
-
- hash[0] += current->pid + jiffies + random_get_entropy();
- md5_transform(hash, random_int_secret);
- ret = *(unsigned long *)hash;
- put_cpu_var(get_random_int_hash);
-
+ batch = &get_cpu_var(batched_entropy_u32);
+ if (batch->position % ARRAY_SIZE(batch->entropy_u32) == 0) {
+ extract_crng((u8 *)batch->entropy_u32);
+ batch->position = 0;
+ }
+ ret = batch->entropy_u32[batch->position++];
+ put_cpu_var(batched_entropy_u32);
return ret;
}
-EXPORT_SYMBOL(get_random_long);
+EXPORT_SYMBOL(get_random_u32);
/**
* randomize_page - Generate a random, page aligned address
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