aboutsummaryrefslogtreecommitdiff
path: root/drivers
diff options
context:
space:
mode:
authorLinus Torvalds <torvalds@linux-foundation.org>2013-03-05 18:54:28 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2013-03-05 18:54:28 -0800
commitd7b815d4daac154a029faf4e8b687a75530d43be (patch)
tree3e9f5f974c2cb5b9911382ee544a44652d7e8ee7 /drivers
parent9da060d0ed571bbff434c4a1ef3e48db99a37ee0 (diff)
parentf7f154f1246ccc5a0a7e9ce50932627d60a0c878 (diff)
downloadvexpress-lsk-d7b815d4daac154a029faf4e8b687a75530d43be.tar.gz
Merge tag 'fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux
Pull virtio hwrng fix from Rusty Russell: "Nasty side-effect of vmalloc'ing modules: their static vars cannot be put into scatterlists. Jens has a check queued for this, so it shouldn't happen again. We could fix this in virtio_rng, but it's actually far easier to just do it in the core" * tag 'fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux: hw_random: make buffer usable in scatterlist.
Diffstat (limited to 'drivers')
-rw-r--r--drivers/char/hw_random/core.c19
1 files changed, 16 insertions, 3 deletions
diff --git a/drivers/char/hw_random/core.c b/drivers/char/hw_random/core.c
index 1bafb40ec8a..69ae5972713 100644
--- a/drivers/char/hw_random/core.c
+++ b/drivers/char/hw_random/core.c
@@ -40,6 +40,7 @@
#include <linux/init.h>
#include <linux/miscdevice.h>
#include <linux/delay.h>
+#include <linux/slab.h>
#include <asm/uaccess.h>
@@ -52,8 +53,12 @@ static struct hwrng *current_rng;
static LIST_HEAD(rng_list);
static DEFINE_MUTEX(rng_mutex);
static int data_avail;
-static u8 rng_buffer[SMP_CACHE_BYTES < 32 ? 32 : SMP_CACHE_BYTES]
- __cacheline_aligned;
+static u8 *rng_buffer;
+
+static size_t rng_buffer_size(void)
+{
+ return SMP_CACHE_BYTES < 32 ? 32 : SMP_CACHE_BYTES;
+}
static inline int hwrng_init(struct hwrng *rng)
{
@@ -116,7 +121,7 @@ static ssize_t rng_dev_read(struct file *filp, char __user *buf,
if (!data_avail) {
bytes_read = rng_get_data(current_rng, rng_buffer,
- sizeof(rng_buffer),
+ rng_buffer_size(),
!(filp->f_flags & O_NONBLOCK));
if (bytes_read < 0) {
err = bytes_read;
@@ -307,6 +312,14 @@ int hwrng_register(struct hwrng *rng)
mutex_lock(&rng_mutex);
+ /* kmalloc makes this safe for virt_to_page() in virtio_rng.c */
+ err = -ENOMEM;
+ if (!rng_buffer) {
+ rng_buffer = kmalloc(rng_buffer_size(), GFP_KERNEL);
+ if (!rng_buffer)
+ goto out_unlock;
+ }
+
/* Must not register two RNGs with the same name. */
err = -EEXIST;
list_for_each_entry(tmp, &rng_list, list) {