Commit d7b815d4 authored by Linus Torvalds's avatar Linus Torvalds
Browse files

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.
parents 9da060d0 f7f154f1
......@@ -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) {
......
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