Subject: linux-next: manual merge of the random tree with the crypto-current tree

From: Stephen Rothwell <[email-masked]>
Date: Tue, 15 Jul 2014 17:30:25 +1000

Hi Theodore,

Today's linux-next merge of the random tree got a conflict in
drivers/char/hw_random/core.c between commit d3cc7996473a ("hwrng:
fetch randomness only after device init") from the crypto-current tree
and commit b77e62203be2 ("hwrng: create filler thread") and
53f52341d87b ("hwrng: add per-device entropy derating") from the random
tree.

I fixed it up (I think - see below) and can carry the fix as necessary
(no action is required).

-- 
Cheers,
Stephen Rothwell                    [email-masked]

diff --cc drivers/char/hw_random/core.c
index c4419ea1ab07,349a3b852be9..000000000000
--- a/drivers/char/hw_random/core.c
+++ b/drivers/char/hw_random/core.c
@@@ -53,42 -55,42 +55,62 @@@ static struct task_struct *hwrng_fill
  static LIST_HEAD(rng_list);
  static DEFINE_MUTEX(rng_mutex);
  static int data_avail;
- static u8 *rng_buffer;
+ static u8 *rng_buffer, *rng_fillbuf;
+ static unsigned short current_quality;
+ static unsigned short default_quality; /* = 0; default to "off" */
+ 
+ module_param(current_quality, ushort, 0644);
+ MODULE_PARM_DESC(current_quality,
+ 		 "current hwrng entropy estimation per mill");
+ module_param(default_quality, ushort, 0644);
+ MODULE_PARM_DESC(default_quality,
+ 		 "default entropy content of hwrng per mill");
+ 
+ static void start_khwrngd(void);
  
 +static inline int rng_get_data(struct hwrng *rng, u8 *buffer, size_t size,
 +			       int wait);
 +
  static size_t rng_buffer_size(void)
  {
  	return SMP_CACHE_BYTES < 32 ? 32 : SMP_CACHE_BYTES;
  }
  
 -static inline int hwrng_init(struct hwrng *rng)
 +static void add_early_randomness(struct hwrng *rng)
  {
 -	int err;
 +	unsigned char bytes[16];
 +	int bytes_read;
 +
 +	/*
 +	 * Currently only virtio-rng cannot return data during device
 +	 * probe, and that's handled in virtio-rng.c itself.  If there
 +	 * are more such devices, this call to rng_get_data can be
 +	 * made conditional here instead of doing it per-device.
 +	 */
 +	bytes_read = rng_get_data(rng, bytes, sizeof(bytes), 1);
 +	if (bytes_read > 0)
 +		add_device_randomness(bytes, bytes_read);
 +}
  
 +static inline int hwrng_init(struct hwrng *rng)
 +{
  	if (rng->init) {
 -		err = rng->init(rng);
 -		if (err)
 -			return err;
 +		int ret;
 +
 +		ret =  rng->init(rng);
 +		if (ret)
 +			return ret;
  	}
 +	add_early_randomness(rng);
+ 
+ 	current_quality = rng->quality ? : default_quality;
+ 	current_quality &= 1023;
+ 
+ 	if (current_quality == 0 && hwrng_fill)
+ 		kthread_stop(hwrng_fill);
+ 	if (current_quality > 0 && !hwrng_fill)
+ 		start_khwrngd();
+ 
  	return 0;
  }