summaryrefslogtreecommitdiff
path: root/drivers/char
diff options
context:
space:
mode:
Diffstat (limited to 'drivers/char')
-rw-r--r--drivers/char/random.c123
1 files changed, 55 insertions, 68 deletions
diff --git a/drivers/char/random.c b/drivers/char/random.c
index 630b9b9e7d25..768dee5e081a 100644
--- a/drivers/char/random.c
+++ b/drivers/char/random.c
@@ -69,7 +69,7 @@
*
* The primary kernel interfaces are:
*
- * void get_random_bytes(void *buf, int nbytes);
+ * void get_random_bytes(void *buf, size_t nbytes);
* u32 get_random_u32()
* u64 get_random_u64()
* unsigned int get_random_int()
@@ -97,14 +97,14 @@
* The current exported interfaces for gathering environmental noise
* from the devices are:
*
- * void add_device_randomness(const void *buf, unsigned int size);
+ * void add_device_randomness(const void *buf, size_t size);
* void add_input_randomness(unsigned int type, unsigned int code,
* unsigned int value);
* void add_interrupt_randomness(int irq);
* void add_disk_randomness(struct gendisk *disk);
- * void add_hwgenerator_randomness(const char *buffer, size_t count,
+ * void add_hwgenerator_randomness(const void *buffer, size_t count,
* size_t entropy);
- * void add_bootloader_randomness(const void *buf, unsigned int size);
+ * void add_bootloader_randomness(const void *buf, size_t size);
*
* add_device_randomness() is for adding data to the random pool that
* is likely to differ between two devices (or possibly even per boot).
@@ -268,7 +268,7 @@ static int crng_init = 0;
#define crng_ready() (likely(crng_init > 1))
static int crng_init_cnt = 0;
static void process_random_ready_list(void);
-static void _get_random_bytes(void *buf, int nbytes);
+static void _get_random_bytes(void *buf, size_t nbytes);
static struct ratelimit_state unseeded_warning =
RATELIMIT_STATE_INIT("warn_unseeded_randomness", HZ, 3);
@@ -290,7 +290,7 @@ MODULE_PARM_DESC(ratelimit_disable, "Disable random ratelimit suppression");
static struct {
struct blake2s_state hash;
spinlock_t lock;
- int entropy_count;
+ unsigned int entropy_count;
} input_pool = {
.hash.h = { BLAKE2S_IV0 ^ (0x01010000 | BLAKE2S_HASH_SIZE),
BLAKE2S_IV1, BLAKE2S_IV2, BLAKE2S_IV3, BLAKE2S_IV4,
@@ -308,18 +308,12 @@ static void crng_reseed(void);
* update the entropy estimate. The caller should call
* credit_entropy_bits if this is appropriate.
*/
-static void _mix_pool_bytes(const void *in, int nbytes)
+static void _mix_pool_bytes(const void *in, size_t nbytes)
{
blake2s_update(&input_pool.hash, in, nbytes);
}
-static void __mix_pool_bytes(const void *in, int nbytes)
-{
- trace_mix_pool_bytes_nolock(nbytes, _RET_IP_);
- _mix_pool_bytes(in, nbytes);
-}
-
-static void mix_pool_bytes(const void *in, int nbytes)
+static void mix_pool_bytes(const void *in, size_t nbytes)
{
unsigned long flags;
@@ -383,18 +377,18 @@ static void process_random_ready_list(void)
spin_unlock_irqrestore(&random_ready_list_lock, flags);
}
-static void credit_entropy_bits(int nbits)
+static void credit_entropy_bits(size_t nbits)
{
- int entropy_count, orig;
+ unsigned int entropy_count, orig, add;
- if (nbits <= 0)
+ if (!nbits)
return;
- nbits = min(nbits, POOL_BITS);
+ add = min_t(size_t, nbits, POOL_BITS);
do {
orig = READ_ONCE(input_pool.entropy_count);
- entropy_count = min(POOL_BITS, orig + nbits);
+ entropy_count = min_t(unsigned int, POOL_BITS, orig + add);
} while (cmpxchg(&input_pool.entropy_count, orig, entropy_count) != orig);
trace_credit_entropy_bits(nbits, entropy_count, _RET_IP_);
@@ -443,10 +437,10 @@ static void invalidate_batched_entropy(void);
* path. So we can't afford to dilly-dally. Returns the number of
* bytes processed from cp.
*/
-static size_t crng_fast_load(const u8 *cp, size_t len)
+static size_t crng_fast_load(const void *cp, size_t len)
{
unsigned long flags;
- u8 *p;
+ const u8 *src = (const u8 *)cp;
size_t ret = 0;
if (!spin_trylock_irqsave(&base_crng.lock, flags))
@@ -455,10 +449,9 @@ static size_t crng_fast_load(const u8 *cp, size_t len)
spin_unlock_irqrestore(&base_crng.lock, flags);
return 0;
}
- p = base_crng.key;
while (len > 0 && crng_init_cnt < CRNG_INIT_CNT_THRESH) {
- p[crng_init_cnt % sizeof(base_crng.key)] ^= *cp;
- cp++; crng_init_cnt++; len--; ret++;
+ base_crng.key[crng_init_cnt % sizeof(base_crng.key)] ^= *src;
+ src++; crng_init_cnt++; len--; ret++;
}
if (crng_init_cnt >= CRNG_INIT_CNT_THRESH) {
invalidate_batched_entropy();
@@ -482,7 +475,7 @@ static size_t crng_fast_load(const u8 *cp, size_t len)
* something like a fixed DMI table (for example), which might very
* well be unique to the machine, but is otherwise unvarying.
*/
-static void crng_slow_load(const u8 *cp, size_t len)
+static void crng_slow_load(const void *cp, size_t len)
{
unsigned long flags;
struct blake2s_state hash;
@@ -656,14 +649,15 @@ static void crng_make_state(u32 chacha_state[CHACHA_STATE_WORDS],
static ssize_t get_random_bytes_user(void __user *buf, size_t nbytes)
{
bool large_request = nbytes > 256;
- ssize_t ret = 0, len;
+ ssize_t ret = 0;
+ size_t len;
u32 chacha_state[CHACHA_STATE_WORDS];
u8 output[CHACHA_BLOCK_SIZE];
if (!nbytes)
return 0;
- len = min_t(ssize_t, 32, nbytes);
+ len = min_t(size_t, 32, nbytes);
crng_make_state(chacha_state, output, len);
if (copy_to_user(buf, output, len))
@@ -683,7 +677,7 @@ static ssize_t get_random_bytes_user(void __user *buf, size_t nbytes)
if (unlikely(chacha_state[12] == 0))
++chacha_state[13];
- len = min_t(ssize_t, nbytes, CHACHA_BLOCK_SIZE);
+ len = min_t(size_t, nbytes, CHACHA_BLOCK_SIZE);
if (copy_to_user(buf, output, len)) {
ret = -EFAULT;
break;
@@ -721,7 +715,7 @@ struct timer_rand_state {
* the entropy pool having similar initial state across largely
* identical devices.
*/
-void add_device_randomness(const void *buf, unsigned int size)
+void add_device_randomness(const void *buf, size_t size)
{
unsigned long time = random_get_entropy() ^ jiffies;
unsigned long flags;
@@ -749,7 +743,7 @@ static struct timer_rand_state input_timer_state = INIT_TIMER_RAND_STATE;
* keyboard scan codes, and 256 upwards for interrupts.
*
*/
-static void add_timer_randomness(struct timer_rand_state *state, unsigned num)
+static void add_timer_randomness(struct timer_rand_state *state, unsigned int num)
{
struct {
long jiffies;
@@ -793,7 +787,7 @@ static void add_timer_randomness(struct timer_rand_state *state, unsigned num)
* Round down by 1 bit on general principles,
* and limit entropy estimate to 12 bits.
*/
- credit_entropy_bits(min_t(int, fls(delta >> 1), 11));
+ credit_entropy_bits(min_t(unsigned int, fls(delta >> 1), 11));
}
void add_input_randomness(unsigned int type, unsigned int code,
@@ -874,8 +868,8 @@ void add_interrupt_randomness(int irq)
add_interrupt_bench(cycles);
if (unlikely(crng_init == 0)) {
- if ((fast_pool->count >= 64) &&
- crng_fast_load((u8 *)fast_pool->pool, sizeof(fast_pool->pool)) > 0) {
+ if (fast_pool->count >= 64 &&
+ crng_fast_load(fast_pool->pool, sizeof(fast_pool->pool)) > 0) {
fast_pool->count = 0;
fast_pool->last = now;
if (spin_trylock(&input_pool.lock)) {
@@ -893,7 +887,7 @@ void add_interrupt_randomness(int irq)
return;
fast_pool->last = now;
- __mix_pool_bytes(&fast_pool->pool, sizeof(fast_pool->pool));
+ _mix_pool_bytes(&fast_pool->pool, sizeof(fast_pool->pool));
spin_unlock(&input_pool.lock);
fast_pool->count = 0;
@@ -1002,18 +996,18 @@ static void _warn_unseeded_randomness(const char *func_name, void *caller, void
* wait_for_random_bytes() should be called and return 0 at least once
* at any point prior.
*/
-static void _get_random_bytes(void *buf, int nbytes)
+static void _get_random_bytes(void *buf, size_t nbytes)
{
u32 chacha_state[CHACHA_STATE_WORDS];
u8 tmp[CHACHA_BLOCK_SIZE];
- ssize_t len;
+ size_t len;
trace_get_random_bytes(nbytes, _RET_IP_);
if (!nbytes)
return;
- len = min_t(ssize_t, 32, nbytes);
+ len = min_t(size_t, 32, nbytes);
crng_make_state(chacha_state, buf, len);
nbytes -= len;
buf += len;
@@ -1036,7 +1030,7 @@ static void _get_random_bytes(void *buf, int nbytes)
memzero_explicit(chacha_state, sizeof(chacha_state));
}
-void get_random_bytes(void *buf, int nbytes)
+void get_random_bytes(void *buf, size_t nbytes)
{
static void *previous;
@@ -1197,25 +1191,19 @@ EXPORT_SYMBOL(del_random_ready_callback);
/*
* This function will use the architecture-specific hardware random
- * number generator if it is available. The arch-specific hw RNG will
- * almost certainly be faster than what we can do in software, but it
- * is impossible to verify that it is implemented securely (as
- * opposed, to, say, the AES encryption of a sequence number using a
- * key known by the NSA). So it's useful if we need the speed, but
- * only if we're willing to trust the hardware manufacturer not to
- * have put in a back door.
- *
- * Return number of bytes filled in.
+ * number generator if it is available. It is not recommended for
+ * use. Use get_random_bytes() instead. It returns the number of
+ * bytes filled in.
*/
-int __must_check get_random_bytes_arch(void *buf, int nbytes)
+size_t __must_check get_random_bytes_arch(void *buf, size_t nbytes)
{
- int left = nbytes;
+ size_t left = nbytes;
u8 *p = buf;
trace_get_random_bytes_arch(left, _RET_IP_);
while (left) {
unsigned long v;
- int chunk = min_t(int, left, sizeof(unsigned long));
+ size_t chunk = min_t(size_t, left, sizeof(unsigned long));
if (!arch_get_random_long(&v))
break;
@@ -1248,12 +1236,12 @@ early_param("random.trust_cpu", parse_trust_cpu);
*/
int __init rand_initialize(void)
{
- int i;
+ size_t i;
ktime_t now = ktime_get_real();
bool arch_init = true;
unsigned long rv;
- for (i = BLAKE2S_BLOCK_SIZE; i > 0; i -= sizeof(rv)) {
+ for (i = 0; i < BLAKE2S_BLOCK_SIZE; i += sizeof(rv)) {
if (!arch_get_random_seed_long_early(&rv) &&
!arch_get_random_long_early(&rv)) {
rv = random_get_entropy();
@@ -1302,7 +1290,7 @@ static ssize_t urandom_read_nowarn(struct file *file, char __user *buf,
nbytes = min_t(size_t, nbytes, INT_MAX >> 6);
ret = get_random_bytes_user(buf, nbytes);
- trace_urandom_read(8 * nbytes, 0, input_pool.entropy_count);
+ trace_urandom_read(nbytes, input_pool.entropy_count);
return ret;
}
@@ -1346,19 +1334,18 @@ static __poll_t random_poll(struct file *file, poll_table *wait)
return mask;
}
-static int write_pool(const char __user *buffer, size_t count)
+static int write_pool(const char __user *ubuf, size_t count)
{
- size_t bytes;
- u8 buf[BLAKE2S_BLOCK_SIZE];
- const char __user *p = buffer;
+ size_t len;
+ u8 block[BLAKE2S_BLOCK_SIZE];
- while (count > 0) {
- bytes = min(count, sizeof(buf));
- if (copy_from_user(buf, p, bytes))
+ while (count) {
+ len = min(count, sizeof(block));
+ if (copy_from_user(block, ubuf, len))
return -EFAULT;
- count -= bytes;
- p += bytes;
- mix_pool_bytes(buf, bytes);
+ count -= len;
+ ubuf += len;
+ mix_pool_bytes(block, len);
cond_resched();
}
@@ -1368,7 +1355,7 @@ static int write_pool(const char __user *buffer, size_t count)
static ssize_t random_write(struct file *file, const char __user *buffer,
size_t count, loff_t *ppos)
{
- size_t ret;
+ int ret;
ret = write_pool(buffer, count);
if (ret)
@@ -1464,8 +1451,6 @@ const struct file_operations urandom_fops = {
SYSCALL_DEFINE3(getrandom, char __user *, buf, size_t, count, unsigned int,
flags)
{
- int ret;
-
if (flags & ~(GRND_NONBLOCK | GRND_RANDOM | GRND_INSECURE))
return -EINVAL;
@@ -1480,6 +1465,8 @@ SYSCALL_DEFINE3(getrandom, char __user *, buf, size_t, count, unsigned int,
count = INT_MAX;
if (!(flags & GRND_INSECURE) && !crng_ready()) {
+ int ret;
+
if (flags & GRND_NONBLOCK)
return -EAGAIN;
ret = wait_for_random_bytes();
@@ -1751,7 +1738,7 @@ unsigned long randomize_page(unsigned long start, unsigned long range)
* Those devices may produce endless random bits and will be throttled
* when our pool is full.
*/
-void add_hwgenerator_randomness(const char *buffer, size_t count,
+void add_hwgenerator_randomness(const void *buffer, size_t count,
size_t entropy)
{
if (unlikely(crng_init == 0)) {
@@ -1782,7 +1769,7 @@ EXPORT_SYMBOL_GPL(add_hwgenerator_randomness);
* it would be regarded as device data.
* The decision is controlled by CONFIG_RANDOM_TRUST_BOOTLOADER.
*/
-void add_bootloader_randomness(const void *buf, unsigned int size)
+void add_bootloader_randomness(const void *buf, size_t size)
{
if (IS_ENABLED(CONFIG_RANDOM_TRUST_BOOTLOADER))
add_hwgenerator_randomness(buf, size, size * 8);
generated by cgit v1.2.3 (git 2.25.1) at 2025-07-23 20:02:26 +0000