diff options
| -rw-r--r-- | drivers/char/random.c | 62 | ||||
| -rw-r--r-- | lib/Kconfig.debug | 3 |
2 files changed, 19 insertions, 46 deletions
diff --git a/drivers/char/random.c b/drivers/char/random.c index 07200b8f4591..3860d534cf05 100644 --- a/drivers/char/random.c +++ b/drivers/char/random.c @@ -87,11 +87,10 @@ static DEFINE_SPINLOCK(random_ready_chain_lock); static RAW_NOTIFIER_HEAD(random_ready_chain); /* Control how we warn userspace. */ -static struct ratelimit_state unseeded_warning = - RATELIMIT_STATE_INIT("warn_unseeded_randomness", HZ, 3); static struct ratelimit_state urandom_warning = RATELIMIT_STATE_INIT("warn_urandom_randomness", HZ, 3); -static int ratelimit_disable __read_mostly; +static int ratelimit_disable __read_mostly = + IS_ENABLED(CONFIG_WARN_ALL_UNSEEDED_RANDOM); module_param_named(ratelimit_disable, ratelimit_disable, int, 0644); MODULE_PARM_DESC(ratelimit_disable, "Disable random ratelimit suppression"); @@ -182,27 +181,15 @@ static void process_random_ready_list(void) spin_unlock_irqrestore(&random_ready_chain_lock, flags); } -#define warn_unseeded_randomness(previous) \ - _warn_unseeded_randomness(__func__, (void *)_RET_IP_, (previous)) +#define warn_unseeded_randomness() \ + _warn_unseeded_randomness(__func__, (void *)_RET_IP_) -static void _warn_unseeded_randomness(const char *func_name, void *caller, void **previous) +static void _warn_unseeded_randomness(const char *func_name, void *caller) { -#ifdef CONFIG_WARN_ALL_UNSEEDED_RANDOM - const bool print_once = false; -#else - static bool print_once __read_mostly; -#endif - - if (print_once || crng_ready() || - (previous && (caller == READ_ONCE(*previous)))) + if (!IS_ENABLED(CONFIG_WARN_ALL_UNSEEDED_RANDOM) || crng_ready()) return; - WRITE_ONCE(*previous, caller); -#ifndef CONFIG_WARN_ALL_UNSEEDED_RANDOM - print_once = true; -#endif - if (__ratelimit(&unseeded_warning)) - printk_deferred(KERN_NOTICE "random: %s called from %pS with crng_init=%d\n", - func_name, caller, crng_init); + printk_deferred(KERN_NOTICE "random: %s called from %pS with crng_init=%d\n", + func_name, caller, crng_init); } @@ -455,9 +442,7 @@ static void _get_random_bytes(void *buf, size_t nbytes) */ void get_random_bytes(void *buf, size_t nbytes) { - static void *previous; - - warn_unseeded_randomness(&previous); + warn_unseeded_randomness(); _get_random_bytes(buf, nbytes); } EXPORT_SYMBOL(get_random_bytes); @@ -553,10 +538,9 @@ u64 get_random_u64(void) u64 ret; unsigned long flags; struct batched_entropy *batch; - static void *previous; unsigned long next_gen; - warn_unseeded_randomness(&previous); + warn_unseeded_randomness(); if (!crng_ready()) { _get_random_bytes(&ret, sizeof(ret)); @@ -592,10 +576,9 @@ u32 get_random_u32(void) u32 ret; unsigned long flags; struct batched_entropy *batch; - static void *previous; unsigned long next_gen; - warn_unseeded_randomness(&previous); + warn_unseeded_randomness(); if (!crng_ready()) { _get_random_bytes(&ret, sizeof(ret)); @@ -822,16 +805,9 @@ static void credit_init_bits(size_t nbits) wake_up_interruptible(&crng_init_wait); kill_fasync(&fasync, SIGIO, POLL_IN); pr_notice("crng init done\n"); - if (unseeded_warning.missed) { - pr_notice("%d get_random_xx warning(s) missed due to ratelimiting\n", - unseeded_warning.missed); - unseeded_warning.missed = 0; - } - if (urandom_warning.missed) { + if (urandom_warning.missed) pr_notice("%d urandom warning(s) missed due to ratelimiting\n", urandom_warning.missed); - urandom_warning.missed = 0; - } } else if (orig < POOL_EARLY_BITS && new >= POOL_EARLY_BITS) { spin_lock_irqsave(&base_crng.lock, flags); /* Check if crng_init is CRNG_EMPTY, to avoid race with crng_reseed(). */ @@ -976,11 +952,6 @@ int __init rand_initialize(void) else if (arch_init && trust_cpu) credit_init_bits(BLAKE2S_BLOCK_SIZE * 8); - if (ratelimit_disable) { - urandom_warning.interval = 0; - unseeded_warning.interval = 0; - } - WARN_ON(register_pm_notifier(&pm_notifier)); WARN(!random_get_entropy(), "Missing cycle counter and fallback timer; RNG " @@ -1487,11 +1458,14 @@ static ssize_t urandom_read(struct file *file, char __user *buf, size_t nbytes, if (!crng_ready()) try_to_generate_entropy(); - if (!crng_ready() && maxwarn > 0) { - maxwarn--; - if (__ratelimit(&urandom_warning)) + if (!crng_ready()) { + if (!ratelimit_disable && maxwarn <= 0) + ++urandom_warning.missed; + else if (ratelimit_disable || __ratelimit(&urandom_warning)) { + --maxwarn; pr_notice("%s: uninitialized urandom read (%zd bytes read)\n", current->comm, nbytes); + } } return get_random_bytes_user(buf, nbytes); diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug index 075cd25363ac..7e282970177a 100644 --- a/lib/Kconfig.debug +++ b/lib/Kconfig.debug @@ -1616,8 +1616,7 @@ config WARN_ALL_UNSEEDED_RANDOM so architecture maintainers really need to do what they can to get the CRNG seeded sooner after the system is booted. However, since users cannot do anything actionable to - address this, by default the kernel will issue only a single - warning for the first use of unseeded randomness. + address this, by default this option is disabled. Say Y here if you want to receive warnings for all uses of unseeded randomness. This will be of use primarily for |