static void double_bit_error_data(void *error_data, void *correct_data,
size_t size)
{
unsigned int offset[2];
offset[0] = prandom_u32() % (size * BITS_PER_BYTE);
do {
offset[1] = prandom_u32() % (size * BITS_PER_BYTE);
} while (offset[0] == offset[1]);
memcpy(error_data, correct_data, size);
__change_bit_le(offset[0], error_data);
__change_bit_le(offset[1], error_data);
}
static unsigned int random_ecc_bit(size_t size)
{
unsigned int offset = prandom_u32() % (3 * BITS_PER_BYTE);
if (size == 256) {
/*
* Don't inject a bit error into the insignificant bits (16th
* and 17th bit) in ECC code for 256 byte data block
*/
while (offset == 16 || offset == 17)
offset = prandom_u32() % (3 * BITS_PER_BYTE);
}
return offset;
}
struct bpf_binary_header *bpf_alloc_binary(unsigned int proglen,
u8 **image_ptr)
{
unsigned int sz, hole;
struct bpf_binary_header *header;
/* Most of BPF filters are really small,
* but if some of them fill a page, allow at least
* 128 extra bytes to insert a random section of int3
*/
sz = round_up(proglen + sizeof(*header) + 128, PAGE_SIZE);
header = module_alloc(sz);
if (!header)
return NULL;
memset(header, 0xcc, sz); /* fill whole space with int3 instructions */
header->pages = sz / PAGE_SIZE;
hole = sz - (proglen + sizeof(*header));
/* insert a random number of int3 instructions before BPF code */
#if LINUX_VERSION_CODE >= KERNEL_VERSION(3,10,0)
*image_ptr = &header->image[prandom_u32() % hole];
#else
*image_ptr = &header->image[32 % hole];
#endif
return header;
}
static int gact_net_rand(struct tcf_gact *gact)
{
smp_rmb(); /* coupled with smp_wmb() in tcf_gact_init() */
if (prandom_u32() % gact->tcfg_pval)
return gact->tcf_action;
return gact->tcfg_paction;
}
static void yam_arbitrate(struct net_device *dev)
{
struct yam_port *yp = netdev_priv(dev);
if (yp->magic != YAM_MAGIC || yp->tx_state != TX_OFF ||
skb_queue_empty(&yp->send_queue))
return;
/* tx_state is TX_OFF and there is data to send */
if (yp->dupmode) {
/* Full duplex mode, don't wait */
yam_start_tx(dev, yp);
return;
}
if (yp->dcd) {
/* DCD on, wait slotime ... */
yp->slotcnt = yp->slot / 10;
return;
}
/* Is slottime passed ? */
if ((--yp->slotcnt) > 0)
return;
yp->slotcnt = yp->slot / 10;
/* is random > persist ? */
if ((prandom_u32() % 256) > yp->pers)
return;
yam_start_tx(dev, yp);
}
int __sbitmap_queue_get(struct sbitmap_queue *sbq)
{
unsigned int hint, depth;
int nr;
hint = this_cpu_read(*sbq->alloc_hint);
depth = READ_ONCE(sbq->sb.depth);
if (unlikely(hint >= depth)) {
hint = depth ? prandom_u32() % depth : 0;
this_cpu_write(*sbq->alloc_hint, hint);
}
nr = sbitmap_get(&sbq->sb, hint, sbq->round_robin);
if (nr == -1) {
/* If the map is full, a hint won't do us much good. */
this_cpu_write(*sbq->alloc_hint, 0);
} else if (nr == hint || unlikely(sbq->round_robin)) {
/* Only update the hint if we used it. */
hint = nr + 1;
if (hint >= depth - 1)
hint = 0;
this_cpu_write(*sbq->alloc_hint, hint);
}
return nr;
}
static int
qtnf_mgmt_tx(struct wiphy *wiphy, struct wireless_dev *wdev,
struct cfg80211_mgmt_tx_params *params, u64 *cookie)
{
struct qtnf_vif *vif = qtnf_netdev_get_priv(wdev->netdev);
const struct ieee80211_mgmt *mgmt_frame = (void *)params->buf;
u32 short_cookie = prandom_u32();
u16 flags = 0;
*cookie = short_cookie;
if (params->offchan)
flags |= QLINK_MGMT_FRAME_TX_FLAG_OFFCHAN;
if (params->no_cck)
flags |= QLINK_MGMT_FRAME_TX_FLAG_NO_CCK;
if (params->dont_wait_for_ack)
flags |= QLINK_MGMT_FRAME_TX_FLAG_ACK_NOWAIT;
pr_debug("%s freq:%u; FC:%.4X; DA:%pM; len:%zu; C:%.8X; FL:%.4X\n",
wdev->netdev->name, params->chan->center_freq,
le16_to_cpu(mgmt_frame->frame_control), mgmt_frame->da,
params->len, short_cookie, flags);
return qtnf_cmd_send_mgmt_frame(vif, short_cookie, flags,
params->chan->center_freq,
params->buf, params->len);
}
static int do_operation(void)
{
if (prandom_u32() & 1)
return do_read();
else
return do_write();
}
/*
* Pick a new monitor at random and set cur_mon. If we are repicking
* (i.e. cur_mon is already set), be sure to pick a different one.
*/
static void pick_new_mon(struct ceph_mon_client *monc)
{
int old_mon = monc->cur_mon;
BUG_ON(monc->monmap->num_mon < 1);
if (monc->monmap->num_mon == 1) {
monc->cur_mon = 0;
} else {
int max = monc->monmap->num_mon;
int o = -1;
int n;
if (monc->cur_mon >= 0) {
if (monc->cur_mon < monc->monmap->num_mon)
o = monc->cur_mon;
if (o >= 0)
max--;
}
n = prandom_u32() % max;
if (o >= 0 && n >= o)
n++;
monc->cur_mon = n;
}
dout("%s mon%d -> mon%d out of %d mons\n", __func__, old_mon,
monc->cur_mon, monc->monmap->num_mon);
}
static struct bpf_binary_header *bpf_alloc_binary(unsigned int proglen,
u8 **image_ptr)
{
unsigned int sz, hole;
struct bpf_binary_header *header;
/* Most of BPF filters are really small,
* but if some of them fill a page, allow at least
* 128 extra bytes to insert a random section of int3
*/
sz = round_up(proglen + sizeof(*header) + 128, PAGE_SIZE);
/*
header = module_alloc(sz);
if (!header)
return NULL;
*/
header = mmap(NULL, sz, PROT_READ|PROT_WRITE|PROT_EXEC,
MAP_PRIVATE|MAP_ANONYMOUS, -1, 0);
if ((void *)header == MAP_FAILED) {
perror("bpf_jit_comp.c: mmap");
exit(EXIT_FAILURE);
}
memset(header, 0xcc, sz); /* fill whole space with int3 instructions */
header->pages = sz / PAGE_SIZE;
hole = min(sz - (proglen + sizeof(*header)), PAGE_SIZE - sizeof(*header));
/* insert a random number of int3 instructions before BPF code */
#define prandom_u32() 0
*image_ptr = &header->image[prandom_u32() % hole];
#undef prandom_u32
return header;
}
/*
* choose a random mds that is "up" (i.e. has a state > 0), or -1.
*/
int ceph_mdsmap_get_random_mds(struct ceph_mdsmap *m)
{
int n = 0;
int i;
/* special case for one mds */
if (1 == m->m_max_mds && m->m_info[0].state > 0)
return 0;
/* count */
for (i = 0; i < m->m_max_mds; i++)
if (m->m_info[i].state > 0)
n++;
if (n == 0)
return -1;
/* pick */
n = prandom_u32() % n;
i = 0;
for (i = 0; n > 0; i++, n--)
while (m->m_info[i].state <= 0)
i++;
return i;
}
void nf_nat_l4proto_unique_tuple(const struct nf_nat_l3proto *l3proto,
struct nf_conntrack_tuple *tuple,
const struct nf_nat_range *range,
enum nf_nat_manip_type maniptype,
const struct nf_conn *ct,
u16 *rover)
{
unsigned int range_size, min, i;
__be16 *portptr;
u_int16_t off;
if (maniptype == NF_NAT_MANIP_SRC)
portptr = &tuple->src.u.all;
else
portptr = &tuple->dst.u.all;
/* If no range specified... */
if (!(range->flags & NF_NAT_RANGE_PROTO_SPECIFIED)) {
/* If it's dst rewrite, can't change port */
if (maniptype == NF_NAT_MANIP_DST)
return;
if (ntohs(*portptr) < 1024) {
/* Loose convention: >> 512 is credential passing */
if (ntohs(*portptr) < 512) {
min = 1;
range_size = 511 - min + 1;
} else {
min = 600;
range_size = 1023 - min + 1;
}
} else {
min = 1024;
range_size = 65535 - 1024 + 1;
}
} else {
min = ntohs(range->min_proto.all);
range_size = ntohs(range->max_proto.all) - min + 1;
}
if (range->flags & NF_NAT_RANGE_PROTO_RANDOM) {
off = l3proto->secure_port(tuple, maniptype == NF_NAT_MANIP_SRC
? tuple->dst.u.all
: tuple->src.u.all);
} else if (range->flags & NF_NAT_RANGE_PROTO_RANDOM_FULLY) {
off = prandom_u32();
} else {
off = *rover;
}
for (i = 0; ; ++off) {
*portptr = htons(min + off % range_size);
if (++i != range_size && nf_nat_used_tuple(tuple, ct))
continue;
if (!(range->flags & NF_NAT_RANGE_PROTO_RANDOM_ALL))
*rover = off;
return;
}
}
static int bitfliptest_do_operation(void)
{
if (prandom_u32() & 1) {
return bitfliptest_do_read();
} else {
return bitfliptest_do_write();
}
}
static void single_bit_error_data(void *error_data, void *correct_data,
size_t size)
{
unsigned int offset = prandom_u32() % (size * BITS_PER_BYTE);
memcpy(error_data, correct_data, size);
__change_bit_le(offset, error_data);
}
static int rand_offs(void)
{
unsigned int offs;
offs = prandom_u32();
offs %= bufsize;
return offs;
}
static int rand_len(int offs)
{
unsigned int len;
len = prandom_u32();
len %= (bufsize - offs);
return len;
}
static int bitfliptest_rand_len(int offs)
{
unsigned int len = 0;
len = prandom_u32();
len %= (bufsize - offs);
return len;
}
static int bitfliptest_rand_offs(void)
{
unsigned int offs = 0;
offs = prandom_u32();
offs %= bufsize;
return offs;
}
inline u32 rtw_random32(void)
{
#ifdef PLATFORM_LINUX
#if (LINUX_VERSION_CODE >= KERNEL_VERSION(3,8,0))
return prandom_u32();
#else
return random32();
#endif
#endif
}
/*
* Get a random new sequence number but make sure it is not greater than
* EXT4_MMP_SEQ_MAX.
*/
static unsigned int mmp_new_seq(void)
{
u32 new_seq;
do {
new_seq = prandom_u32();
} while (new_seq > EXT4_MMP_SEQ_MAX);
return new_seq;
}
static int __init find_bit_test(void)
{
unsigned long nbits = BITMAP_LEN / SPARSE;
pr_err("\nStart testing find_bit() with random-filled bitmap\n");
get_random_bytes(bitmap, sizeof(bitmap));
get_random_bytes(bitmap2, sizeof(bitmap2));
test_find_next_bit(bitmap, BITMAP_LEN);
test_find_next_zero_bit(bitmap, BITMAP_LEN);
test_find_last_bit(bitmap, BITMAP_LEN);
/*
* test_find_first_bit() may take some time, so
* traverse only part of bitmap to avoid soft lockup.
*/
test_find_first_bit(bitmap, BITMAP_LEN / 10);
test_find_next_and_bit(bitmap, bitmap2, BITMAP_LEN);
pr_err("\nStart testing find_bit() with sparse bitmap\n");
bitmap_zero(bitmap, BITMAP_LEN);
bitmap_zero(bitmap2, BITMAP_LEN);
while (nbits--) {
__set_bit(prandom_u32() % BITMAP_LEN, bitmap);
__set_bit(prandom_u32() % BITMAP_LEN, bitmap2);
}
test_find_next_bit(bitmap, BITMAP_LEN);
test_find_next_zero_bit(bitmap, BITMAP_LEN);
test_find_last_bit(bitmap, BITMAP_LEN);
test_find_first_bit(bitmap, BITMAP_LEN);
test_find_next_and_bit(bitmap, bitmap2, BITMAP_LEN);
/*
* Everything is OK. Return error just to let user run benchmark
* again without annoying rmmod.
*/
return -EINVAL;
}
static ssize_t r_coin(struct file *f, char __user *b,
size_t cnt, loff_t *lf)
{
char *ret;
u32 value = prandom_u32() % 2;
ret = msg[value];
stats[value]++;
return simple_read_from_buffer(b, cnt,
lf, ret,
strlen(ret));
}
static void __uuid_gen_common(__u8 b[16])
{
int i;
u32 r;
for (i = 0; i < 4; i++) {
r = prandom_u32();
memcpy(b + i * 4, &r, 4);
}
/* reversion 0b10 */
b[8] = (b[8] & 0x3F) | 0x80;
}
static int bitfliptest_rand_eb(void)
{
unsigned int eb = 0;
again:
eb = prandom_u32();
/* Read or write up 2 eraseblocks at a time - hence 'ebcnt - 1' */
eb %= (ebcnt - 1);
if (bbt[eb])
goto again;
return eb;
}
static int sfq_init(struct Qdisc *sch, struct nlattr *opt)
{
struct sfq_sched_data *q = qdisc_priv(sch);
int i;
q->perturb_timer.function = sfq_perturbation;
q->perturb_timer.data = (unsigned long)sch;
init_timer_deferrable(&q->perturb_timer);
for (i = 0; i < SFQ_MAX_DEPTH + 1; i++) {
q->dep[i].next = i + SFQ_MAX_FLOWS;
q->dep[i].prev = i + SFQ_MAX_FLOWS;
}
q->limit = SFQ_MAX_DEPTH;
q->maxdepth = SFQ_MAX_DEPTH;
q->cur_depth = 0;
q->tail = NULL;
q->divisor = SFQ_DEFAULT_HASH_DIVISOR;
q->maxflows = SFQ_DEFAULT_FLOWS;
q->quantum = psched_mtu(qdisc_dev(sch));
q->scaled_quantum = SFQ_ALLOT_SIZE(q->quantum);
q->perturb_period = 0;
q->perturbation = prandom_u32();
if (opt) {
int err = sfq_change(sch, opt);
if (err)
return err;
}
q->ht = sfq_alloc(sizeof(q->ht[0]) * q->divisor);
q->slots = sfq_alloc(sizeof(q->slots[0]) * q->maxflows);
if (!q->ht || !q->slots) {
sfq_destroy(sch);
return -ENOMEM;
}
for (i = 0; i < q->divisor; i++)
q->ht[i] = SFQ_EMPTY_SLOT;
for (i = 0; i < q->maxflows; i++) {
slot_queue_init(&q->slots[i]);
sfq_link(q, i);
}
if (q->limit >= 1)
sch->flags |= TCQ_F_CAN_BYPASS;
else
sch->flags &= ~TCQ_F_CAN_BYPASS;
return 0;
}
static void makedata(int disks)
{
int i, j;
for (i = 0; i < disks; i++) {
for (j = 0; j < PAGE_SIZE/sizeof(u32); j += sizeof(u32)) {
u32 *p = page_address(data[i]) + j;
*p = prandom_u32();
}
dataptrs[i] = data[i];
}
}
inline u32 rtw_random32(void)
{
#ifdef PLATFORM_LINUX
#if (LINUX_VERSION_CODE >= KERNEL_VERSION(3,8,0))
return prandom_u32();
#else
return random32();
#endif
#elif defined(PLATFORM_WINDOWS)
#error "to be implemented\n"
#elif defined(PLATFORM_FREEBSD)
#error "to be implemented\n"
#endif
}
/* returns -ve errno or +ve port */
static int rds_add_bound(struct rds_sock *rs, __be32 addr, __be16 *port)
{
int ret = -EADDRINUSE;
u16 rover, last;
u64 key;
if (*port != 0) {
rover = be16_to_cpu(*port);
if (rover == RDS_FLAG_PROBE_PORT)
return -EINVAL;
last = rover;
} else {
rover = max_t(u16, prandom_u32(), 2);
last = rover - 1;
}
do {
if (rover == 0)
rover++;
if (rover == RDS_FLAG_PROBE_PORT)
continue;
key = ((u64)addr << 32) | cpu_to_be16(rover);
if (rhashtable_lookup_fast(&bind_hash_table, &key, ht_parms))
continue;
rs->rs_bound_key = key;
rs->rs_bound_addr = addr;
net_get_random_once(&rs->rs_hash_initval,
sizeof(rs->rs_hash_initval));
rs->rs_bound_port = cpu_to_be16(rover);
rs->rs_bound_node.next = NULL;
rds_sock_addref(rs);
if (!rhashtable_insert_fast(&bind_hash_table,
&rs->rs_bound_node, ht_parms)) {
*port = rs->rs_bound_port;
ret = 0;
rdsdebug("rs %p binding to %pI4:%d\n",
rs, &addr, (int)ntohs(*port));
break;
} else {
rds_sock_put(rs);
ret = -ENOMEM;
break;
}
} while (rover++ != last);
return ret;
}
/*
* use the kernel prandom call to pick a new random level. This
* uses P = .50. If you bump the SKIP_MAXLEVEL past 32 levels,
* this function needs updating.
*/
int skiplist_get_new_level(struct sl_list *list, int max_level)
{
int level = 0;
unsigned long randseed;
randseed = prandom_u32();
while (randseed && (randseed & 1)) {
randseed >>= 1;
level++;
if (level == max_level)
break;
}
return (level >= SKIP_MAXLEVEL ? SKIP_MAXLEVEL - 1: level);
}
static void sfq_perturbation(unsigned long arg)
{
struct Qdisc *sch = (struct Qdisc *)arg;
struct sfq_sched_data *q = qdisc_priv(sch);
spinlock_t *root_lock = qdisc_lock(qdisc_root_sleeping(sch));
spin_lock(root_lock);
q->perturbation = prandom_u32();
if (!q->filter_list && q->tail)
sfq_rehash(sch);
spin_unlock(root_lock);
if (q->perturb_period)
mod_timer(&q->perturb_timer, jiffies + q->perturb_period);
}
