Commit 30f4236a authored by NeilBrown's avatar NeilBrown Committed by Greg Kroah-Hartman
Browse files

staging: lustre: replace cfs_srand() calls with add_device_randomness(). 



The only places that cfs_srand is called, the random bits are
mixed with bits from get_random_bytes().  So it is equally effective
to add entropy to either pool.
So we can replace calls to cfs_srand() with calls that add the
entropy with add_device_randomness().  That function adds time-based
entropy, so we can discard the ktime_get_ts64 calls.

One location in lustre_handles.c only adds timebased
entropy.  This cannot improve the entropy provided by get_random_bytes(),
so just discard that call.

Signed-off-by: default avatarNeilBrown <neilb@suse.com>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent bcfa98a5

drivers/staging/lustre/lnet/lnet/router.c

+6 −9
Original line number Diff line number Diff line
@@ -238,28 +238,25 @@ lnet_find_net_locked(__u32 net) 
static void lnet_shuffle_seed(void)

{

	static int seeded;

	__u32 lnd_type, seed[2];

	struct timespec64 ts;

	struct lnet_ni *ni;



	if (seeded)

		return;



	cfs_get_random_bytes(seed, sizeof(seed));



	/*

	 * Nodes with small feet have little entropy

	 * the NID for this node gives the most entropy in the low bits

	 */

	list_for_each_entry(ni, &the_lnet.ln_nis, ni_list) {

		lnd_type = LNET_NETTYP(LNET_NIDNET(ni->ni_nid));

		__u32 lnd_type, seed;



		if (lnd_type != LOLND)

			seed[0] ^= (LNET_NIDADDR(ni->ni_nid) | lnd_type);

		lnd_type = LNET_NETTYP(LNET_NIDNET(ni->ni_nid));

		if (lnd_type != LOLND) {

			seed = (LNET_NIDADDR(ni->ni_nid) | lnd_type);

			add_device_randomness(&seed, sizeof(seed));

		}

	}



	ktime_get_ts64(&ts);

	cfs_srand(ts.tv_sec ^ seed[0], ts.tv_nsec ^ seed[1]);

	seeded = 1;

}

drivers/staging/lustre/lustre/llite/super25.c

+7 −10
Original line number Diff line number Diff line
@@ -86,8 +86,7 @@ MODULE_ALIAS_FS("lustre"); 
static int __init lustre_init(void)

{

	struct lnet_process_id lnet_id;

	struct timespec64 ts;

	int i, rc, seed[2];

	int i, rc;



	BUILD_BUG_ON(sizeof(LUSTRE_VOLATILE_HDR) !=

		     LUSTRE_VOLATILE_HDR_LEN + 1);
@@ -126,21 +125,19 @@ static int __init lustre_init(void) 
		goto out_debugfs;

	}



	cfs_get_random_bytes(seed, sizeof(seed));



	/* Nodes with small feet have little entropy. The NID for this

	 * node gives the most entropy in the low bits

	 */

	for (i = 0;; i++) {

		u32 seed;



		if (LNetGetId(i, &lnet_id) == -ENOENT)

			break;



		if (LNET_NETTYP(LNET_NIDNET(lnet_id.nid)) != LOLND)

			seed[0] ^= LNET_NIDADDR(lnet_id.nid);

		if (LNET_NETTYP(LNET_NIDNET(lnet_id.nid)) != LOLND) {

			 seed = LNET_NIDADDR(lnet_id.nid);

			 add_device_randomness(&seed, sizeof(seed));

		}

	}



	ktime_get_ts64(&ts);

	cfs_srand(ts.tv_sec ^ seed[0], ts.tv_nsec ^ seed[1]);



	rc = vvp_global_init();

	if (rc != 0)

drivers/staging/lustre/lustre/obdclass/lustre_handles.c

+0 −7
Original line number Diff line number Diff line
@@ -181,8 +181,6 @@ EXPORT_SYMBOL(class_handle_free_cb); 
int class_handle_init(void)

{

	struct handle_bucket *bucket;

	struct timespec64 ts;

	int seed[2];



	LASSERT(!handle_hash);
@@ -198,11 +196,6 @@ int class_handle_init(void) 
		spin_lock_init(&bucket->lock);

	}



	/** bug 21430: add randomness to the initial base */

	cfs_get_random_bytes(seed, sizeof(seed));

	ktime_get_ts64(&ts);

	cfs_srand(ts.tv_sec ^ seed[0], ts.tv_nsec ^ seed[1]);



	cfs_get_random_bytes(&handle_base, sizeof(handle_base));

	LASSERT(handle_base != 0ULL);