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| author | Linus Torvalds <torvalds@linux-foundation.org> | 2013-03-05 18:54:28 -0800 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2013-03-05 18:54:28 -0800 |
| commit | d7b815d4daac154a029faf4e8b687a75530d43be (patch) | |
| tree | 3e9f5f974c2cb5b9911382ee544a44652d7e8ee7 /drivers | |
| parent | 9da060d0ed571bbff434c4a1ef3e48db99a37ee0 (diff) | |
| parent | f7f154f1246ccc5a0a7e9ce50932627d60a0c878 (diff) | |
| download | linux-d7b815d4daac154a029faf4e8b687a75530d43be.tar.bz2 | |
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.c | 19 |
1 files changed, 16 insertions, 3 deletions
diff --git a/drivers/char/hw_random/core.c b/drivers/char/hw_random/core.c index 1bafb40ec8a2..69ae5972713c 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) { |