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authorLinus Torvalds <torvalds@linux-foundation.org>2018-04-26 20:59:56 +0300
committerLinus Torvalds <torvalds@linux-foundation.org>2018-04-26 20:59:56 +0300
commit665fa0000aedb5f3d6b4d3b040d323074e1b7c40 (patch)
tree96c8b50e34fda7390edc340d690d9921416ec673 /drivers
parent1334ac11d93167fcc2953e9dd71837459b97d610 (diff)
parent4e00b339e264802851aff8e73cde7d24b57b18ce (diff)
downloadlinux-665fa0000aedb5f3d6b4d3b040d323074e1b7c40.tar.xz
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
Diffstat (limited to 'drivers')
-rw-r--r--drivers/char/random.c48
1 files changed, 42 insertions, 6 deletions
diff --git a/drivers/char/random.c b/drivers/char/random.c
index 3cd3aae24d6d..cd888d4ee605 100644
--- a/drivers/char/random.c
+++ b/drivers/char/random.c
@@ -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);