Commit 665fa000 authored by Linus Torvalds's avatar Linus Torvalds
Browse files

Merge tag 'random_for_linus_stable' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/random

Pull /dev/random fixes from Ted Ts'o:
 "Fix a regression on NUMA kernels and suppress excess unseeded entropy
  pool warnings"

* tag 'random_for_linus_stable' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/random:
  random: rate limit unseeded randomness warnings
  random: fix possible sleeping allocation from irq context
parents 1334ac11 4e00b339
......@@ -261,6 +261,7 @@
#include <linux/ptrace.h>
#include <linux/workqueue.h>
#include <linux/irq.h>
#include <linux/ratelimit.h>
#include <linux/syscalls.h>
#include <linux/completion.h>
#include <linux/uuid.h>
......@@ -438,6 +439,16 @@ static void _crng_backtrack_protect(struct crng_state *crng,
static void process_random_ready_list(void);
static void _get_random_bytes(void *buf, int nbytes);
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;
module_param_named(ratelimit_disable, ratelimit_disable, int, 0644);
MODULE_PARM_DESC(ratelimit_disable, "Disable random ratelimit suppression");
/**********************************************************************
*
* OS independent entropy store. Here are the functions which handle
......@@ -789,7 +800,7 @@ static void crng_initialize(struct crng_state *crng)
}
#ifdef CONFIG_NUMA
static void numa_crng_init(void)
static void do_numa_crng_init(struct work_struct *work)
{
int i;
struct crng_state *crng;
......@@ -810,6 +821,13 @@ static void numa_crng_init(void)
kfree(pool);
}
}
static DECLARE_WORK(numa_crng_init_work, do_numa_crng_init);
static void numa_crng_init(void)
{
schedule_work(&numa_crng_init_work);
}
#else
static void numa_crng_init(void) {}
#endif
......@@ -925,6 +943,18 @@ static void crng_reseed(struct crng_state *crng, struct entropy_store *r)
process_random_ready_list();
wake_up_interruptible(&crng_init_wait);
pr_notice("random: crng init done\n");
if (unseeded_warning.missed) {
pr_notice("random: %d get_random_xx warning(s) missed "
"due to ratelimiting\n",
unseeded_warning.missed);
unseeded_warning.missed = 0;
}
if (urandom_warning.missed) {
pr_notice("random: %d urandom warning(s) missed "
"due to ratelimiting\n",
urandom_warning.missed);
urandom_warning.missed = 0;
}
}
}
......@@ -1565,8 +1595,9 @@ static void _warn_unseeded_randomness(const char *func_name, void *caller,
#ifndef CONFIG_WARN_ALL_UNSEEDED_RANDOM
print_once = true;
#endif
pr_notice("random: %s called from %pS with crng_init=%d\n",
func_name, caller, crng_init);
if (__ratelimit(&unseeded_warning))
pr_notice("random: %s called from %pS with crng_init=%d\n",
func_name, caller, crng_init);
}
/*
......@@ -1760,6 +1791,10 @@ static int rand_initialize(void)
init_std_data(&blocking_pool);
crng_initialize(&primary_crng);
crng_global_init_time = jiffies;
if (ratelimit_disable) {
urandom_warning.interval = 0;
unseeded_warning.interval = 0;
}
return 0;
}
early_initcall(rand_initialize);
......@@ -1827,9 +1862,10 @@ urandom_read(struct file *file, char __user *buf, size_t nbytes, loff_t *ppos)
if (!crng_ready() && maxwarn > 0) {
maxwarn--;
printk(KERN_NOTICE "random: %s: uninitialized urandom read "
"(%zd bytes read)\n",
current->comm, nbytes);
if (__ratelimit(&urandom_warning))
printk(KERN_NOTICE "random: %s: uninitialized "
"urandom read (%zd bytes read)\n",
current->comm, nbytes);
spin_lock_irqsave(&primary_crng.lock, flags);
crng_init_cnt = 0;
spin_unlock_irqrestore(&primary_crng.lock, flags);
......
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