[PATCH v4 1/6] treewide: use prandom_u32_max() when possible, mechanically

Jason A. Donenfeld
2022-10-07T18:01:02Z

Rather than incurring a division or requesting too many random bytes for
the given range, use the prandom_u32_max() function, which only takes
the minimum required bytes from the RNG and avoids divisions. This was
done mechanically with these coccinelle scripts:

@no_modulo@
expression E;
@@
- (prandom_u32() % (E))
+ prandom_u32_max(E)
@no_modulo@
expression E;
@@
- (get_random_u32() % (E))
+ prandom_u32_max(E)
@no_modulo@
expression E;
@@
- (get_random_int() % (E))
+ prandom_u32_max(E)

Reviewed-by: Kees Cook <keescook@chromium.org>
Reviewed-by: KP Singh <kpsingh@kernel.org>
Reviewed-by: Jan Kara <jack@suse.cz> # for ext4 and sbitmap
Acked-by: Ulf Hansson <ulf.hansson@linaro.org> # for mmc
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
---
arch/arm/kernel/process.c | 2 +-
arch/s390/kernel/vdso.c | 2 +-
arch/um/kernel/process.c | 2 +-
arch/x86/entry/vdso/vma.c | 2 +-
arch/x86/kernel/module.c | 2 +-
arch/x86/kernel/process.c | 2 +-
arch/x86/mm/pat/cpa-test.c | 4 +-
crypto/testmgr.c | 86 +++++++++----------
.../gpu/drm/i915/gem/i915_gem_execbuffer.c | 2 +-
drivers/infiniband/core/cma.c | 2 +-
drivers/infiniband/hw/cxgb4/id_table.c | 4 +-
drivers/infiniband/hw/hns/hns_roce_ah.c | 5 +-
drivers/infiniband/ulp/rtrs/rtrs-clt.c | 3 +-
.../test-drivers/vivid/vivid-touch-cap.c | 2 +-
drivers/mmc/core/core.c | 4 +-
drivers/mmc/host/dw_mmc.c | 2 +-
drivers/mtd/nand/raw/nandsim.c | 4 +-
drivers/mtd/tests/mtd_nandecctest.c | 10 +--
drivers/mtd/ubi/debug.c | 2 +-
.../chelsio/inline_crypto/chtls/chtls_io.c | 4 +-
drivers/net/hamradio/baycom_epp.c | 2 +-
drivers/net/hamradio/hdlcdrv.c | 2 +-
drivers/net/hamradio/yam.c | 2 +-
drivers/net/phy/at803x.c | 2 +-
.../broadcom/brcm80211/brcmfmac/p2p.c | 2 +-
.../net/wireless/intel/iwlwifi/mvm/mac-ctxt.c | 2 +-
drivers/scsi/fcoe/fcoe_ctlr.c | 4 +-
drivers/scsi/qedi/qedi_main.c | 2 +-
fs/ceph/inode.c | 2 +-
fs/ceph/mdsmap.c | 2 +-
fs/ext4/super.c | 7 +-
fs/f2fs/gc.c | 2 +-
fs/f2fs/segment.c | 8 +-
fs/ubifs/debug.c | 8 +-
fs/ubifs/lpt_commit.c | 12 +--
fs/xfs/xfs_error.c | 2 +-
kernel/bpf/core.c | 4 +-
kernel/locking/test-ww_mutex.c | 4 +-
kernel/time/clocksource.c | 2 +-
lib/cmdline_kunit.c | 4 +-
lib/fault-inject.c | 2 +-
lib/find_bit_benchmark.c | 4 +-
lib/reed_solomon/test_rslib.c | 4 +-
lib/sbitmap.c | 2 +-
lib/test-string_helpers.c | 2 +-
lib/test_hexdump.c | 10 +--
lib/test_kasan.c | 6 +-
lib/test_list_sort.c | 2 +-
mm/migrate.c | 2 +-
mm/slub.c | 2 +-
net/ceph/mon_client.c | 2 +-
net/ceph/osd_client.c | 2 +-
net/core/neighbour.c | 2 +-
net/core/pktgen.c | 39 ++++-----
net/core/stream.c | 2 +-
net/ipv4/igmp.c | 6 +-
net/ipv4/inet_connection_sock.c | 2 +-
net/ipv6/addrconf.c | 8 +-
net/ipv6/mcast.c | 10 +--
net/netfilter/ipvs/ip_vs_twos.c | 4 +-
net/packet/af_packet.c | 2 +-
net/sched/act_gact.c | 2 +-
net/sched/act_sample.c | 2 +-
net/sched/sch_netem.c | 4 +-
net/sctp/socket.c | 2 +-
net/tipc/socket.c | 2 +-
net/xfrm/xfrm_state.c | 2 +-
67 files changed, 173 insertions(+), 177 deletions(-)

diff --git a/arch/arm/kernel/process.c b/arch/arm/kernel/process.c
index 3d9cace63884..35129ae36067 100644
--- a/arch/arm/kernel/process.c
+++ b/arch/arm/kernel/process.c
@@ -375,7 +375,7 @@ static unsigned long sigpage_addr(const struct mm_struct *mm,

slots = ((last - first) >> PAGE_SHIFT) + 1;

- offset = get_random_int() % slots;
+ offset = prandom_u32_max(slots);

addr = first + (offset << PAGE_SHIFT);

diff --git a/arch/s390/kernel/vdso.c b/arch/s390/kernel/vdso.c
index 5075cde77b29..a6b5db59cf40 100644
--- a/arch/s390/kernel/vdso.c
+++ b/arch/s390/kernel/vdso.c
@@ -226,7 +226,7 @@ static unsigned long vdso_addr(unsigned long start, unsigned long len)
end -= len;

if (end > start) {
- offset = get_random_int() % (((end - start) >> PAGE_SHIFT) + 1);
+ offset = prandom_u32_max(((end - start) >> PAGE_SHIFT) + 1);
addr = start + (offset << PAGE_SHIFT);
} else {
addr = start;
diff --git a/arch/um/kernel/process.c b/arch/um/kernel/process.c
index 80b90b1276a1..010bc422a09d 100644
--- a/arch/um/kernel/process.c
+++ b/arch/um/kernel/process.c
@@ -356,7 +356,7 @@ int singlestepping(void * t)
unsigned long arch_align_stack(unsigned long sp)
{
if (!(current->personality & ADDR_NO_RANDOMIZE) && randomize_va_space)
- sp -= get_random_int() % 8192;
+ sp -= prandom_u32_max(8192);
return sp & ~0xf;
}
#endif
diff --git a/arch/x86/entry/vdso/vma.c b/arch/x86/entry/vdso/vma.c
index 1000d457c332..b64c58c6940f 100644
--- a/arch/x86/entry/vdso/vma.c
+++ b/arch/x86/entry/vdso/vma.c
@@ -327,7 +327,7 @@ static unsigned long vdso_addr(unsigned long start, unsigned len)
end -= len;

if (end > start) {
- offset = get_random_int() % (((end - start) >> PAGE_SHIFT) + 1);
+ offset = prandom_u32_max(((end - start) >> PAGE_SHIFT) + 1);
addr = start + (offset << PAGE_SHIFT);
} else {
addr = start;
diff --git a/arch/x86/kernel/module.c b/arch/x86/kernel/module.c
index b1abf663417c..c032edcd3d95 100644
--- a/arch/x86/kernel/module.c
+++ b/arch/x86/kernel/module.c
@@ -53,7 +53,7 @@ static unsigned long int get_module_load_offset(void)
*/
if (module_load_offset == 0)
module_load_offset =
- (get_random_int() % 1024 + 1) * PAGE_SIZE;
+ (prandom_u32_max(1024) + 1) * PAGE_SIZE;
mutex_unlock(&module_kaslr_mutex);
}
return module_load_offset;
diff --git a/arch/x86/kernel/process.c b/arch/x86/kernel/process.c
index 58a6ea472db9..c21b7347a26d 100644
--- a/arch/x86/kernel/process.c
+++ b/arch/x86/kernel/process.c
@@ -965,7 +965,7 @@ early_param("idle", idle_setup);
unsigned long arch_align_stack(unsigned long sp)
{
if (!(current->personality & ADDR_NO_RANDOMIZE) && randomize_va_space)
- sp -= get_random_int() % 8192;
+ sp -= prandom_u32_max(8192);
return sp & ~0xf;
}

diff --git a/arch/x86/mm/pat/cpa-test.c b/arch/x86/mm/pat/cpa-test.c
index 0612a73638a8..423b21e80929 100644
--- a/arch/x86/mm/pat/cpa-test.c
+++ b/arch/x86/mm/pat/cpa-test.c
@@ -136,10 +136,10 @@ static int pageattr_test(void)
failed += print_split(&sa);

for (i = 0; i < NTEST; i++) {
- unsigned long pfn = prandom_u32() % max_pfn_mapped;
+ unsigned long pfn = prandom_u32_max(max_pfn_mapped);

addr[i] = (unsigned long)__va(pfn << PAGE_SHIFT);
- len[i] = prandom_u32() % NPAGES;
+ len[i] = prandom_u32_max(NPAGES);
len[i] = min_t(unsigned long, len[i], max_pfn_mapped - pfn - 1);

if (len[i] == 0)
diff --git a/crypto/testmgr.c b/crypto/testmgr.c
index 5349ffee6bbd..be45217acde4 100644
--- a/crypto/testmgr.c
+++ b/crypto/testmgr.c
@@ -855,9 +855,9 @@ static int prepare_keybuf(const u8 *key, unsigned int ksize,
/* Generate a random length in range [0, max_len], but prefer smaller values */
static unsigned int generate_random_length(unsigned int max_len)
{
- unsigned int len = prandom_u32() % (max_len + 1);
+ unsigned int len = prandom_u32_max(max_len + 1);

- switch (prandom_u32() % 4) {
+ switch (prandom_u32_max(4)) {
case 0:
return len % 64;
case 1:
@@ -874,14 +874,14 @@ static void flip_random_bit(u8 *buf, size_t size)
{
size_t bitpos;

- bitpos = prandom_u32() % (size * 8);
+ bitpos = prandom_u32_max(size * 8);
buf[bitpos / 8] ^= 1 << (bitpos % 8);
}

/* Flip a random byte in the given nonempty data buffer */
static void flip_random_byte(u8 *buf, size_t size)
{
- buf[prandom_u32() % size] ^= 0xff;
+ buf[prandom_u32_max(size)] ^= 0xff;
}

/* Sometimes make some random changes to the given nonempty data buffer */
@@ -891,15 +891,15 @@ static void mutate_buffer(u8 *buf, size_t size)
size_t i;

/* Sometimes flip some bits */
- if (prandom_u32() % 4 == 0) {
- num_flips = min_t(size_t, 1 << (prandom_u32() % 8), size * 8);
+ if (prandom_u32_max(4) == 0) {
+ num_flips = min_t(size_t, 1 << prandom_u32_max(8), size * 8);
for (i = 0; i < num_flips; i++)
flip_random_bit(buf, size);
}

/* Sometimes flip some bytes */
- if (prandom_u32() % 4 == 0) {
- num_flips = min_t(size_t, 1 << (prandom_u32() % 8), size);
+ if (prandom_u32_max(4) == 0) {
+ num_flips = min_t(size_t, 1 << prandom_u32_max(8), size);
for (i = 0; i < num_flips; i++)
flip_random_byte(buf, size);
}
@@ -915,11 +915,11 @@ static void generate_random_bytes(u8 *buf, size_t count)
if (count == 0)
return;

- switch (prandom_u32() % 8) { /* Choose a generation strategy */
+ switch (prandom_u32_max(8)) { /* Choose a generation strategy */
case 0:
case 1:
/* All the same byte, plus optional mutations */
- switch (prandom_u32() % 4) {
+ switch (prandom_u32_max(4)) {
case 0:
b = 0x00;
break;
@@ -959,24 +959,24 @@ static char *generate_random_sgl_divisions(struct test_sg_division *divs,
unsigned int this_len;
const char *flushtype_str;

- if (div == &divs[max_divs - 1] || prandom_u32() % 2 == 0)
+ if (div == &divs[max_divs - 1] || prandom_u32_max(2) == 0)
this_len = remaining;
else
- this_len = 1 + (prandom_u32() % remaining);
+ this_len = 1 + prandom_u32_max(remaining);
div->proportion_of_total = this_len;

- if (prandom_u32() % 4 == 0)
- div->offset = (PAGE_SIZE - 128) + (prandom_u32() % 128);
- else if (prandom_u32() % 2 == 0)
- div->offset = prandom_u32() % 32;
+ if (prandom_u32_max(4) == 0)
+ div->offset = (PAGE_SIZE - 128) + prandom_u32_max(128);
+ else if (prandom_u32_max(2) == 0)
+ div->offset = prandom_u32_max(32);
else
- div->offset = prandom_u32() % PAGE_SIZE;
- if (prandom_u32() % 8 == 0)
+ div->offset = prandom_u32_max(PAGE_SIZE);
+ if (prandom_u32_max(8) == 0)
div->offset_relative_to_alignmask = true;

div->flush_type = FLUSH_TYPE_NONE;
if (gen_flushes) {
- switch (prandom_u32() % 4) {
+ switch (prandom_u32_max(4)) {
case 0:
div->flush_type = FLUSH_TYPE_REIMPORT;
break;
@@ -988,7 +988,7 @@ static char *generate_random_sgl_divisions(struct test_sg_division *divs,

if (div->flush_type != FLUSH_TYPE_NONE &&
!(req_flags & CRYPTO_TFM_REQ_MAY_SLEEP) &&
- prandom_u32() % 2 == 0)
+ prandom_u32_max(2) == 0)
div->nosimd = true;

switch (div->flush_type) {
@@ -1035,7 +1035,7 @@ static void generate_random_testvec_config(struct testvec_config *cfg,

p += scnprintf(p, end - p, "random:");

- switch (prandom_u32() % 4) {
+ switch (prandom_u32_max(4)) {
case 0:
case 1:
cfg->inplace_mode = OUT_OF_PLACE;
@@ -1050,12 +1050,12 @@ static void generate_random_testvec_config(struct testvec_config *cfg,
break;
}

- if (prandom_u32() % 2 == 0) {
+ if (prandom_u32_max(2) == 0) {
cfg->req_flags |= CRYPTO_TFM_REQ_MAY_SLEEP;
p += scnprintf(p, end - p, " may_sleep");
}

- switch (prandom_u32() % 4) {
+ switch (prandom_u32_max(4)) {
case 0:
cfg->finalization_type = FINALIZATION_TYPE_FINAL;
p += scnprintf(p, end - p, " use_final");
@@ -1071,7 +1071,7 @@ static void generate_random_testvec_config(struct testvec_config *cfg,
}

if (!(cfg->req_flags & CRYPTO_TFM_REQ_MAY_SLEEP) &&
- prandom_u32() % 2 == 0) {
+ prandom_u32_max(2) == 0) {
cfg->nosimd = true;
p += scnprintf(p, end - p, " nosimd");
}
@@ -1084,7 +1084,7 @@ static void generate_random_testvec_config(struct testvec_config *cfg,
cfg->req_flags);
p += scnprintf(p, end - p, "]");

- if (cfg->inplace_mode == OUT_OF_PLACE && prandom_u32() % 2 == 0) {
+ if (cfg->inplace_mode == OUT_OF_PLACE && prandom_u32_max(2) == 0) {
p += scnprintf(p, end - p, " dst_divs=[");
p = generate_random_sgl_divisions(cfg->dst_divs,
ARRAY_SIZE(cfg->dst_divs),
@@ -1093,13 +1093,13 @@ static void generate_random_testvec_config(struct testvec_config *cfg,
p += scnprintf(p, end - p, "]");
}

- if (prandom_u32() % 2 == 0) {
- cfg->iv_offset = 1 + (prandom_u32() % MAX_ALGAPI_ALIGNMASK);
+ if (prandom_u32_max(2) == 0) {
+ cfg->iv_offset = 1 + prandom_u32_max(MAX_ALGAPI_ALIGNMASK);
p += scnprintf(p, end - p, " iv_offset=%u", cfg->iv_offset);
}

- if (prandom_u32() % 2 == 0) {
- cfg->key_offset = 1 + (prandom_u32() % MAX_ALGAPI_ALIGNMASK);
+ if (prandom_u32_max(2) == 0) {
+ cfg->key_offset = 1 + prandom_u32_max(MAX_ALGAPI_ALIGNMASK);
p += scnprintf(p, end - p, " key_offset=%u", cfg->key_offset);
}

@@ -1652,8 +1652,8 @@ static void generate_random_hash_testvec(struct shash_desc *desc,
vec->ksize = 0;
if (maxkeysize) {
vec->ksize = maxkeysize;
- if (prandom_u32() % 4 == 0)
- vec->ksize = 1 + (prandom_u32() % maxkeysize);
+ if (prandom_u32_max(4) == 0)
+ vec->ksize = 1 + prandom_u32_max(maxkeysize);
generate_random_bytes((u8 *)vec->key, vec->ksize);

vec->setkey_error = crypto_shash_setkey(desc->tfm, vec->key,
@@ -2218,13 +2218,13 @@ static void mutate_aead_message(struct aead_testvec *vec, bool aad_iv,
const unsigned int aad_tail_size = aad_iv ? ivsize : 0;
const unsigned int authsize = vec->clen - vec->plen;

- if (prandom_u32() % 2 == 0 && vec->alen > aad_tail_size) {
+ if (prandom_u32_max(2) == 0 && vec->alen > aad_tail_size) {
/* Mutate the AAD */
flip_random_bit((u8 *)vec->assoc, vec->alen - aad_tail_size);
- if (prandom_u32() % 2 == 0)
+ if (prandom_u32_max(2) == 0)
return;
}
- if (prandom_u32() % 2 == 0) {
+ if (prandom_u32_max(2) == 0) {
/* Mutate auth tag (assuming it's at the end of ciphertext) */
flip_random_bit((u8 *)vec->ctext + vec->plen, authsize);
} else {
@@ -2249,7 +2249,7 @@ static void generate_aead_message(struct aead_request *req,
const unsigned int ivsize = crypto_aead_ivsize(tfm);
const unsigned int authsize = vec->clen - vec->plen;
const bool inauthentic = (authsize >= MIN_COLLISION_FREE_AUTHSIZE) &&
- (prefer_inauthentic || prandom_u32() % 4 == 0);
+ (prefer_inauthentic || prandom_u32_max(4) == 0);

/* Generate the AAD. */
generate_random_bytes((u8 *)vec->assoc, vec->alen);
@@ -2257,7 +2257,7 @@ static void generate_aead_message(struct aead_request *req,
/* Avoid implementation-defined behavior. */
memcpy((u8 *)vec->assoc + vec->alen - ivsize, vec->iv, ivsize);

- if (inauthentic && prandom_u32() % 2 == 0) {
+ if (inauthentic && prandom_u32_max(2) == 0) {
/* Generate a random ciphertext. */
generate_random_bytes((u8 *)vec->ctext, vec->clen);
} else {
@@ -2321,8 +2321,8 @@ static void generate_random_aead_testvec(struct aead_request *req,

/* Key: length in [0, maxkeysize], but usually choose maxkeysize */
vec->klen = maxkeysize;
- if (prandom_u32() % 4 == 0)
- vec->klen = prandom_u32() % (maxkeysize + 1);
+ if (prandom_u32_max(4) == 0)
+ vec->klen = prandom_u32_max(maxkeysize + 1);
generate_random_bytes((u8 *)vec->key, vec->klen);
vec->setkey_error = crypto_aead_setkey(tfm, vec->key, vec->klen);

@@ -2331,8 +2331,8 @@ static void generate_random_aead_testvec(struct aead_request *req,

/* Tag length: in [0, maxauthsize], but usually choose maxauthsize */
authsize = maxauthsize;
- if (prandom_u32() % 4 == 0)
- authsize = prandom_u32() % (maxauthsize + 1);
+ if (prandom_u32_max(4) == 0)
+ authsize = prandom_u32_max(maxauthsize + 1);
if (prefer_inauthentic && authsize < MIN_COLLISION_FREE_AUTHSIZE)
authsize = MIN_COLLISION_FREE_AUTHSIZE;
if (WARN_ON(authsize > maxdatasize))
@@ -2342,7 +2342,7 @@ static void generate_random_aead_testvec(struct aead_request *req,

/* AAD, plaintext, and ciphertext lengths */
total_len = generate_random_length(maxdatasize);
- if (prandom_u32() % 4 == 0)
+ if (prandom_u32_max(4) == 0)
vec->alen = 0;
else
vec->alen = generate_random_length(total_len);
@@ -2958,8 +2958,8 @@ static void generate_random_cipher_testvec(struct skcipher_request *req,

/* Key: length in [0, maxkeysize], but usually choose maxkeysize */
vec->klen = maxkeysize;
- if (prandom_u32() % 4 == 0)
- vec->klen = prandom_u32() % (maxkeysize + 1);
+ if (prandom_u32_max(4) == 0)
+ vec->klen = prandom_u32_max(maxkeysize + 1);
generate_random_bytes((u8 *)vec->key, vec->klen);
vec->setkey_error = crypto_skcipher_setkey(tfm, vec->key, vec->klen);

diff --git a/drivers/gpu/drm/i915/gem/i915_gem_execbuffer.c b/drivers/gpu/drm/i915/gem/i915_gem_execbuffer.c
index cd75b0ca2555..845023c14eb3 100644
--- a/drivers/gpu/drm/i915/gem/i915_gem_execbuffer.c
+++ b/drivers/gpu/drm/i915/gem/i915_gem_execbuffer.c
@@ -2424,7 +2424,7 @@ gen8_dispatch_bsd_engine(struct drm_i915_private *dev_priv,
/* Check whether the file_priv has already selected one ring. */
if ((int)file_priv->bsd_engine < 0)
file_priv->bsd_engine =
- get_random_int() % num_vcs_engines(dev_priv);
+ prandom_u32_max(num_vcs_engines(dev_priv));

return file_priv->bsd_engine;
}
diff --git a/drivers/infiniband/core/cma.c b/drivers/infiniband/core/cma.c
index be317f2665a9..d460935e89eb 100644
--- a/drivers/infiniband/core/cma.c
+++ b/drivers/infiniband/core/cma.c
@@ -3759,7 +3759,7 @@ static int cma_alloc_any_port(enum rdma_ucm_port_space ps,

inet_get_local_port_range(net, &low, &high);
remaining = (high - low) + 1;
- rover = prandom_u32() % remaining + low;
+ rover = prandom_u32_max(remaining) + low;
retry:
if (last_used_port != rover) {
struct rdma_bind_list *bind_list;
diff --git a/drivers/infiniband/hw/cxgb4/id_table.c b/drivers/infiniband/hw/cxgb4/id_table.c
index f64e7e02b129..280d61466855 100644
--- a/drivers/infiniband/hw/cxgb4/id_table.c
+++ b/drivers/infiniband/hw/cxgb4/id_table.c
@@ -54,7 +54,7 @@ u32 c4iw_id_alloc(struct c4iw_id_table *alloc)

if (obj < alloc->max) {
if (alloc->flags & C4IW_ID_TABLE_F_RANDOM)
- alloc->last += prandom_u32() % RANDOM_SKIP;
+ alloc->last += prandom_u32_max(RANDOM_SKIP);
else
alloc->last = obj + 1;
if (alloc->last >= alloc->max)
@@ -85,7 +85,7 @@ int c4iw_id_table_alloc(struct c4iw_id_table *alloc, u32 start, u32 num,
alloc->start = start;
alloc->flags = flags;
if (flags & C4IW_ID_TABLE_F_RANDOM)
- alloc->last = prandom_u32() % RANDOM_SKIP;
+ alloc->last = prandom_u32_max(RANDOM_SKIP);
else
alloc->last = 0;
alloc->max = num;
diff --git a/drivers/infiniband/hw/hns/hns_roce_ah.c b/drivers/infiniband/hw/hns/hns_roce_ah.c
index 492b122d0521..480c062dd04f 100644
--- a/drivers/infiniband/hw/hns/hns_roce_ah.c
+++ b/drivers/infiniband/hw/hns/hns_roce_ah.c
@@ -41,9 +41,8 @@ static inline u16 get_ah_udp_sport(const struct rdma_ah_attr *ah_attr)
u16 sport;

if (!fl)
- sport = get_random_u32() %
- (IB_ROCE_UDP_ENCAP_VALID_PORT_MAX + 1 -
- IB_ROCE_UDP_ENCAP_VALID_PORT_MIN) +
+ sport = prandom_u32_max(IB_ROCE_UDP_ENCAP_VALID_PORT_MAX + 1 -
+ IB_ROCE_UDP_ENCAP_VALID_PORT_MIN) +
IB_ROCE_UDP_ENCAP_VALID_PORT_MIN;
else
sport = rdma_flow_label_to_udp_sport(fl);
diff --git a/drivers/infiniband/ulp/rtrs/rtrs-clt.c b/drivers/infiniband/ulp/rtrs/rtrs-clt.c
index 449904dac0a9..e2a89d7f52df 100644
--- a/drivers/infiniband/ulp/rtrs/rtrs-clt.c
+++ b/drivers/infiniband/ulp/rtrs/rtrs-clt.c
@@ -1511,8 +1511,7 @@ static void rtrs_clt_err_recovery_work(struct work_struct *work)
rtrs_clt_stop_and_destroy_conns(clt_path);
queue_delayed_work(rtrs_wq, &clt_path->reconnect_dwork,
msecs_to_jiffies(delay_ms +
- prandom_u32() %
- RTRS_RECONNECT_SEED));
+ prandom_u32_max(RTRS_RECONNECT_SEED)));
}

static struct rtrs_clt_path *alloc_path(struct rtrs_clt_sess *clt,
diff --git a/drivers/media/test-drivers/vivid/vivid-touch-cap.c b/drivers/media/test-drivers/vivid/vivid-touch-cap.c
index 64e3e4cb30c2..792660a85bc1 100644
--- a/drivers/media/test-drivers/vivid/vivid-touch-cap.c
+++ b/drivers/media/test-drivers/vivid/vivid-touch-cap.c
@@ -221,7 +221,7 @@ static void vivid_fill_buff_noise(__s16 *tch_buf, int size)

static inline int get_random_pressure(void)
{
- return get_random_int() % VIVID_PRESSURE_LIMIT;
+ return prandom_u32_max(VIVID_PRESSURE_LIMIT);
}

static void vivid_tch_buf_set(struct v4l2_pix_format *f,
diff --git a/drivers/mmc/core/core.c b/drivers/mmc/core/core.c
index ef53a2578824..95fa8fb1d45f 100644
--- a/drivers/mmc/core/core.c
+++ b/drivers/mmc/core/core.c
@@ -97,8 +97,8 @@ static void mmc_should_fail_request(struct mmc_host *host,
!should_fail(&host->fail_mmc_request, data->blksz * data->blocks))
return;

- data->error = data_errors[prandom_u32() % ARRAY_SIZE(data_errors)];
- data->bytes_xfered = (prandom_u32() % (data->bytes_xfered >> 9)) << 9;
+ data->error = data_errors[prandom_u32_max(ARRAY_SIZE(data_errors))];
+ data->bytes_xfered = prandom_u32_max(data->bytes_xfered >> 9) << 9;
}

#else /* CONFIG_FAIL_MMC_REQUEST */
diff --git a/drivers/mmc/host/dw_mmc.c b/drivers/mmc/host/dw_mmc.c
index 581614196a84..c78bbc22e0d1 100644
--- a/drivers/mmc/host/dw_mmc.c
+++ b/drivers/mmc/host/dw_mmc.c
@@ -1858,7 +1858,7 @@ static void dw_mci_start_fault_timer(struct dw_mci *host)
* Try to inject the error at random points during the data transfer.
*/
hrtimer_start(&host->fault_timer,
- ms_to_ktime(prandom_u32() % 25),
+ ms_to_ktime(prandom_u32_max(25)),
HRTIMER_MODE_REL);
}

diff --git a/drivers/mtd/nand/raw/nandsim.c b/drivers/mtd/nand/raw/nandsim.c
index 24beade95c7f..50bcf745e816 100644
--- a/drivers/mtd/nand/raw/nandsim.c
+++ b/drivers/mtd/nand/raw/nandsim.c
@@ -1405,9 +1405,9 @@ static void ns_do_bit_flips(struct nandsim *ns, int num)
if (bitflips && prandom_u32() < (1 << 22)) {
int flips = 1;
if (bitflips > 1)
- flips = (prandom_u32() % (int) bitflips) + 1;
+ flips = prandom_u32_max(bitflips) + 1;
while (flips--) {
- int pos = prandom_u32() % (num * 8);
+ int pos = prandom_u32_max(num * 8);
ns->buf.byte[pos / 8] ^= (1 << (pos % 8));
NS_WARN("read_page: flipping bit %d in page %d "
"reading from %d ecc: corrected=%u failed=%u\n",
diff --git a/drivers/mtd/tests/mtd_nandecctest.c b/drivers/mtd/tests/mtd_nandecctest.c
index c4f271314f52..1c7201b0f372 100644
--- a/drivers/mtd/tests/mtd_nandecctest.c
+++ b/drivers/mtd/tests/mtd_nandecctest.c
@@ -47,7 +47,7 @@ struct nand_ecc_test {
static void single_bit_error_data(void *error_data, void *correct_data,
size_t size)
{
- unsigned int offset = prandom_u32() % (size * BITS_PER_BYTE);
+ unsigned int offset = prandom_u32_max(size * BITS_PER_BYTE);

memcpy(error_data, correct_data, size);
__change_bit_le(offset, error_data);
@@ -58,9 +58,9 @@ static void double_bit_error_data(void *error_data, void *correct_data,
{
unsigned int offset[2];

- offset[0] = prandom_u32() % (size * BITS_PER_BYTE);
+ offset[0] = prandom_u32_max(size * BITS_PER_BYTE);
do {
- offset[1] = prandom_u32() % (size * BITS_PER_BYTE);
+ offset[1] = prandom_u32_max(size * BITS_PER_BYTE);
} while (offset[0] == offset[1]);

memcpy(error_data, correct_data, size);
@@ -71,7 +71,7 @@ static void double_bit_error_data(void *error_data, void *correct_data,

static unsigned int random_ecc_bit(size_t size)
{
- unsigned int offset = prandom_u32() % (3 * BITS_PER_BYTE);
+ unsigned int offset = prandom_u32_max(3 * BITS_PER_BYTE);

if (size == 256) {
/*
@@ -79,7 +79,7 @@ static unsigned int random_ecc_bit(size_t size)
* and 17th bit) in ECC code for 256 byte data block
*/
while (offset == 16 || offset == 17)
- offset = prandom_u32() % (3 * BITS_PER_BYTE);
+ offset = prandom_u32_max(3 * BITS_PER_BYTE);
}

return offset;
diff --git a/drivers/mtd/ubi/debug.c b/drivers/mtd/ubi/debug.c
index 31d427ee191a..908d0e088557 100644
--- a/drivers/mtd/ubi/debug.c
+++ b/drivers/mtd/ubi/debug.c
@@ -590,7 +590,7 @@ int ubi_dbg_power_cut(struct ubi_device *ubi, int caller)

if (ubi->dbg.power_cut_max > ubi->dbg.power_cut_min) {
range = ubi->dbg.power_cut_max - ubi->dbg.power_cut_min;
- ubi->dbg.power_cut_counter += prandom_u32() % range;
+ ubi->dbg.power_cut_counter += prandom_u32_max(range);
}
return 0;
}
diff --git a/drivers/net/ethernet/chelsio/inline_crypto/chtls/chtls_io.c b/drivers/net/ethernet/chelsio/inline_crypto/chtls/chtls_io.c
index 539992dad8ba..a4256087ac82 100644
--- a/drivers/net/ethernet/chelsio/inline_crypto/chtls/chtls_io.c
+++ b/drivers/net/ethernet/chelsio/inline_crypto/chtls/chtls_io.c
@@ -919,8 +919,8 @@ static int csk_wait_memory(struct chtls_dev *cdev,
current_timeo = *timeo_p;
noblock = (*timeo_p ? false : true);
if (csk_mem_free(cdev, sk)) {
- current_timeo = (prandom_u32() % (HZ / 5)) + 2;
- vm_wait = (prandom_u32() % (HZ / 5)) + 2;
+ current_timeo = prandom_u32_max(HZ / 5) + 2;
+ vm_wait = prandom_u32_max(HZ / 5) + 2;
}

add_wait_queue(sk_sleep(sk), &wait);
diff --git a/drivers/net/hamradio/baycom_epp.c b/drivers/net/hamradio/baycom_epp.c
index 3e69079ed694..7df78a721b04 100644
--- a/drivers/net/hamradio/baycom_epp.c
+++ b/drivers/net/hamradio/baycom_epp.c
@@ -438,7 +438,7 @@ static int transmit(struct baycom_state *bc, int cnt, unsigned char stat)
if ((--bc->hdlctx.slotcnt) > 0)
return 0;
bc->hdlctx.slotcnt = bc->ch_params.slottime;
- if ((prandom_u32() % 256) > bc->ch_params.ppersist)
+ if (prandom_u32_max(256) > bc->ch_params.ppersist)
return 0;
}
}
diff --git a/drivers/net/hamradio/hdlcdrv.c b/drivers/net/hamradio/hdlcdrv.c
index 8297411e87ea..360d041a62c4 100644
--- a/drivers/net/hamradio/hdlcdrv.c
+++ b/drivers/net/hamradio/hdlcdrv.c
@@ -377,7 +377,7 @@ void hdlcdrv_arbitrate(struct net_device *dev, struct hdlcdrv_state *s)
if ((--s->hdlctx.slotcnt) > 0)
return;
s->hdlctx.slotcnt = s->ch_params.slottime;
- if ((prandom_u32() % 256) > s->ch_params.ppersist)
+ if (prandom_u32_max(256) > s->ch_params.ppersist)
return;
start_tx(dev, s);
}
diff --git a/drivers/net/hamradio/yam.c b/drivers/net/hamradio/yam.c
index 980f2be32f05..97a6cc5c7ae8 100644
--- a/drivers/net/hamradio/yam.c
+++ b/drivers/net/hamradio/yam.c
@@ -626,7 +626,7 @@ static void yam_arbitrate(struct net_device *dev)
yp->slotcnt = yp->slot / 10;

/* is random > persist ? */
- if ((prandom_u32() % 256) > yp->pers)
+ if (prandom_u32_max(256) > yp->pers)
return;

yam_start_tx(dev, yp);
diff --git a/drivers/net/phy/at803x.c b/drivers/net/phy/at803x.c
index 59fe356942b5..2a7108361246 100644
--- a/drivers/net/phy/at803x.c
+++ b/drivers/net/phy/at803x.c
@@ -1732,7 +1732,7 @@ static int qca808x_phy_fast_retrain_config(struct phy_device *phydev)

static int qca808x_phy_ms_random_seed_set(struct phy_device *phydev)
{
- u16 seed_value = (prandom_u32() % QCA808X_MASTER_SLAVE_SEED_RANGE);
+ u16 seed_value = prandom_u32_max(QCA808X_MASTER_SLAVE_SEED_RANGE);

return at803x_debug_reg_mask(phydev, QCA808X_PHY_DEBUG_LOCAL_SEED,
QCA808X_MASTER_SLAVE_SEED_CFG,
diff --git a/drivers/net/wireless/broadcom/brcm80211/brcmfmac/p2p.c b/drivers/net/wireless/broadcom/brcm80211/brcmfmac/p2p.c
index 479041f070f9..10d9d9c63b28 100644
--- a/drivers/net/wireless/broadcom/brcm80211/brcmfmac/p2p.c
+++ b/drivers/net/wireless/broadcom/brcm80211/brcmfmac/p2p.c
@@ -1128,7 +1128,7 @@ static void brcmf_p2p_afx_handler(struct work_struct *work)
if (afx_hdl->is_listen && afx_hdl->my_listen_chan)
/* 100ms ~ 300ms */
err = brcmf_p2p_discover_listen(p2p, afx_hdl->my_listen_chan,
- 100 * (1 + prandom_u32() % 3));
+ 100 * (1 + prandom_u32_max(3)));
else
err = brcmf_p2p_act_frm_search(p2p, afx_hdl->peer_listen_chan);

diff --git a/drivers/net/wireless/intel/iwlwifi/mvm/mac-ctxt.c b/drivers/net/wireless/intel/iwlwifi/mvm/mac-ctxt.c
index ed586e6d7d64..de0c545d50fd 100644
--- a/drivers/net/wireless/intel/iwlwifi/mvm/mac-ctxt.c
+++ b/drivers/net/wireless/intel/iwlwifi/mvm/mac-ctxt.c
@@ -1099,7 +1099,7 @@ static void iwl_mvm_mac_ctxt_cmd_fill_ap(struct iwl_mvm *mvm,
iwl_mvm_mac_ap_iterator, &data);

if (data.beacon_device_ts) {
- u32 rand = (prandom_u32() % (64 - 36)) + 36;
+ u32 rand = prandom_u32_max(64 - 36) + 36;
mvmvif->ap_beacon_time = data.beacon_device_ts +
ieee80211_tu_to_usec(data.beacon_int * rand /
100);
diff --git a/drivers/scsi/fcoe/fcoe_ctlr.c b/drivers/scsi/fcoe/fcoe_ctlr.c
index 39e16eab47aa..ddc048069af2 100644
--- a/drivers/scsi/fcoe/fcoe_ctlr.c
+++ b/drivers/scsi/fcoe/fcoe_ctlr.c
@@ -2233,7 +2233,7 @@ static void fcoe_ctlr_vn_restart(struct fcoe_ctlr *fip)

if (fip->probe_tries < FIP_VN_RLIM_COUNT) {
fip->probe_tries++;
- wait = prandom_u32() % FIP_VN_PROBE_WAIT;
+ wait = prandom_u32_max(FIP_VN_PROBE_WAIT);
} else
wait = FIP_VN_RLIM_INT;
mod_timer(&fip->timer, jiffies + msecs_to_jiffies(wait));
@@ -3125,7 +3125,7 @@ static void fcoe_ctlr_vn_timeout(struct fcoe_ctlr *fip)
fcoe_all_vn2vn, 0);
fip->port_ka_time = jiffies +
msecs_to_jiffies(FIP_VN_BEACON_INT +
- (prandom_u32() % FIP_VN_BEACON_FUZZ));
+ prandom_u32_max(FIP_VN_BEACON_FUZZ));
}
if (time_before(fip->port_ka_time, next_time))
next_time = fip->port_ka_time;
diff --git a/drivers/scsi/qedi/qedi_main.c b/drivers/scsi/qedi/qedi_main.c
index cecfb2cb4c7b..df2fe7bd26d1 100644
--- a/drivers/scsi/qedi/qedi_main.c
+++ b/drivers/scsi/qedi/qedi_main.c
@@ -618,7 +618,7 @@ static int qedi_cm_alloc_mem(struct qedi_ctx *qedi)
sizeof(struct qedi_endpoint *)), GFP_KERNEL);
if (!qedi->ep_tbl)
return -ENOMEM;
- port_id = prandom_u32() % QEDI_LOCAL_PORT_RANGE;
+ port_id = prandom_u32_max(QEDI_LOCAL_PORT_RANGE);
if (qedi_init_id_tbl(&qedi->lcl_port_tbl, QEDI_LOCAL_PORT_RANGE,
QEDI_LOCAL_PORT_MIN, port_id)) {
qedi_cm_free_mem(qedi);
diff --git a/fs/ceph/inode.c b/fs/ceph/inode.c
index 42351d7a0dd6..f0c6e7e7b92b 100644
--- a/fs/ceph/inode.c
+++ b/fs/ceph/inode.c
@@ -362,7 +362,7 @@ static int ceph_fill_fragtree(struct inode *inode,
if (nsplits != ci->i_fragtree_nsplits) {
update = true;
} else if (nsplits) {
- i = prandom_u32() % nsplits;
+ i = prandom_u32_max(nsplits);
id = le32_to_cpu(fragtree->splits[i].frag);
if (!__ceph_find_frag(ci, id))
update = true;
diff --git a/fs/ceph/mdsmap.c b/fs/ceph/mdsmap.c
index 8d0a6d2c2da4..3fbabc98e1f7 100644
--- a/fs/ceph/mdsmap.c
+++ b/fs/ceph/mdsmap.c
@@ -29,7 +29,7 @@ static int __mdsmap_get_random_mds(struct ceph_mdsmap *m, bool ignore_laggy)
return -1;

/* pick */
- n = prandom_u32() % n;
+ n = prandom_u32_max(n);
for (j = 0, i = 0; i < m->possible_max_rank; i++) {
if (CEPH_MDS_IS_READY(i, ignore_laggy))
j++;
diff --git a/fs/ext4/super.c b/fs/ext4/super.c
index 9a66abcca1a8..4af351320075 100644
--- a/fs/ext4/super.c
+++ b/fs/ext4/super.c
@@ -3811,8 +3811,7 @@ static int ext4_lazyinit_thread(void *arg)
}
if (!progress) {
elr->lr_next_sched = jiffies +
- (prandom_u32()
- % (EXT4_DEF_LI_MAX_START_DELAY * HZ));
+ prandom_u32_max(EXT4_DEF_LI_MAX_START_DELAY * HZ);
}
if (time_before(elr->lr_next_sched, next_wakeup))
next_wakeup = elr->lr_next_sched;
@@ -3959,8 +3958,8 @@ static struct ext4_li_request *ext4_li_request_new(struct super_block *sb,
* spread the inode table initialization requests
* better.
*/
- elr->lr_next_sched = jiffies + (prandom_u32() %
- (EXT4_DEF_LI_MAX_START_DELAY * HZ));
+ elr->lr_next_sched = jiffies + prandom_u32_max(
+ EXT4_DEF_LI_MAX_START_DELAY * HZ);
return elr;
}

diff --git a/fs/f2fs/gc.c b/fs/f2fs/gc.c
index 6da21d405ce1..2c5fd1db3a3e 100644
--- a/fs/f2fs/gc.c
+++ b/fs/f2fs/gc.c
@@ -285,7 +285,7 @@ static void select_policy(struct f2fs_sb_info *sbi, int gc_type,

/* let's select beginning hot/small space first in no_heap mode*/
if (f2fs_need_rand_seg(sbi))
- p->offset = prandom_u32() % (MAIN_SECS(sbi) * sbi->segs_per_sec);
+ p->offset = prandom_u32_max(MAIN_SECS(sbi) * sbi->segs_per_sec);
else if (test_opt(sbi, NOHEAP) &&
(type == CURSEG_HOT_DATA || IS_NODESEG(type)))
p->offset = 0;
diff --git a/fs/f2fs/segment.c b/fs/f2fs/segment.c
index 0de21f82d7bc..507f77f839f3 100644
--- a/fs/f2fs/segment.c
+++ b/fs/f2fs/segment.c
@@ -2535,7 +2535,7 @@ static unsigned int __get_next_segno(struct f2fs_sb_info *sbi, int type)

sanity_check_seg_type(sbi, seg_type);
if (f2fs_need_rand_seg(sbi))
- return prandom_u32() % (MAIN_SECS(sbi) * sbi->segs_per_sec);
+ return prandom_u32_max(MAIN_SECS(sbi) * sbi->segs_per_sec);

/* if segs_per_sec is large than 1, we need to keep original policy. */
if (__is_large_section(sbi))
@@ -2589,7 +2589,7 @@ static void new_curseg(struct f2fs_sb_info *sbi, int type, bool new_sec)
curseg->alloc_type = LFS;
if (F2FS_OPTION(sbi).fs_mode == FS_MODE_FRAGMENT_BLK)
curseg->fragment_remained_chunk =
- prandom_u32() % sbi->max_fragment_chunk + 1;
+ prandom_u32_max(sbi->max_fragment_chunk) + 1;
}

static int __next_free_blkoff(struct f2fs_sb_info *sbi,
@@ -2626,9 +2626,9 @@ static void __refresh_next_blkoff(struct f2fs_sb_info *sbi,
/* To allocate block chunks in different sizes, use random number */
if (--seg->fragment_remained_chunk <= 0) {
seg->fragment_remained_chunk =
- prandom_u32() % sbi->max_fragment_chunk + 1;
+ prandom_u32_max(sbi->max_fragment_chunk) + 1;
seg->next_blkoff +=
- prandom_u32() % sbi->max_fragment_hole + 1;
+ prandom_u32_max(sbi->max_fragment_hole) + 1;
}
}
}
diff --git a/fs/ubifs/debug.c b/fs/ubifs/debug.c
index fc718f6178f2..f4d3b568aa64 100644
--- a/fs/ubifs/debug.c
+++ b/fs/ubifs/debug.c
@@ -2467,7 +2467,7 @@ int dbg_check_nondata_nodes_order(struct ubifs_info *c, struct list_head *head)

static inline int chance(unsigned int n, unsigned int out_of)
{
- return !!((prandom_u32() % out_of) + 1 <= n);
+ return !!(prandom_u32_max(out_of) + 1 <= n);

}

@@ -2485,13 +2485,13 @@ static int power_cut_emulated(struct ubifs_info *c, int lnum, int write)
if (chance(1, 2)) {
d->pc_delay = 1;
/* Fail within 1 minute */
- delay = prandom_u32() % 60000;
+ delay = prandom_u32_max(60000);
d->pc_timeout = jiffies;
d->pc_timeout += msecs_to_jiffies(delay);
ubifs_warn(c, "failing after %lums", delay);
} else {
d->pc_delay = 2;
- delay = prandom_u32() % 10000;
+ delay = prandom_u32_max(10000);
/* Fail within 10000 operations */
d->pc_cnt_max = delay;
ubifs_warn(c, "failing after %lu calls", delay);
@@ -2571,7 +2571,7 @@ static int corrupt_data(const struct ubifs_info *c, const void *buf,
unsigned int from, to, ffs = chance(1, 2);
unsigned char *p = (void *)buf;

- from = prandom_u32() % len;
+ from = prandom_u32_max(len);
/* Corruption span max to end of write unit */
to = min(len, ALIGN(from + 1, c->max_write_size));

diff --git a/fs/ubifs/lpt_commit.c b/fs/ubifs/lpt_commit.c
index d76a19e460cd..cd4d5726a78d 100644
--- a/fs/ubifs/lpt_commit.c
+++ b/fs/ubifs/lpt_commit.c
@@ -1977,21 +1977,21 @@ static int dbg_populate_lsave(struct ubifs_info *c)
c->lsave[i] = c->main_first;

list_for_each_entry(lprops, &c->empty_list, list)
- c->lsave[prandom_u32() % c->lsave_cnt] = lprops->lnum;
+ c->lsave[prandom_u32_max(c->lsave_cnt)] = lprops->lnum;
list_for_each_entry(lprops, &c->freeable_list, list)
- c->lsave[prandom_u32() % c->lsave_cnt] = lprops->lnum;
+ c->lsave[prandom_u32_max(c->lsave_cnt)] = lprops->lnum;
list_for_each_entry(lprops, &c->frdi_idx_list, list)
- c->lsave[prandom_u32() % c->lsave_cnt] = lprops->lnum;
+ c->lsave[prandom_u32_max(c->lsave_cnt)] = lprops->lnum;

heap = &c->lpt_heap[LPROPS_DIRTY_IDX - 1];
for (i = 0; i < heap->cnt; i++)
- c->lsave[prandom_u32() % c->lsave_cnt] = heap->arr[i]->lnum;
+ c->lsave[prandom_u32_max(c->lsave_cnt)] = heap->arr[i]->lnum;
heap = &c->lpt_heap[LPROPS_DIRTY - 1];
for (i = 0; i < heap->cnt; i++)
- c->lsave[prandom_u32() % c->lsave_cnt] = heap->arr[i]->lnum;
+ c->lsave[prandom_u32_max(c->lsave_cnt)] = heap->arr[i]->lnum;
heap = &c->lpt_heap[LPROPS_FREE - 1];
for (i = 0; i < heap->cnt; i++)
- c->lsave[prandom_u32() % c->lsave_cnt] = heap->arr[i]->lnum;
+ c->lsave[prandom_u32_max(c->lsave_cnt)] = heap->arr[i]->lnum;

return 1;
}
diff --git a/fs/xfs/xfs_error.c b/fs/xfs/xfs_error.c
index 296faa41d81d..7db588ed0be5 100644
--- a/fs/xfs/xfs_error.c
+++ b/fs/xfs/xfs_error.c
@@ -274,7 +274,7 @@ xfs_errortag_test(

ASSERT(error_tag < XFS_ERRTAG_MAX);
randfactor = mp->m_errortag[error_tag];
- if (!randfactor || prandom_u32() % randfactor)
+ if (!randfactor || prandom_u32_max(randfactor))
return false;

xfs_warn_ratelimited(mp,
diff --git a/kernel/bpf/core.c b/kernel/bpf/core.c
index 3d9eb3ae334c..ade6b03b1d9b 100644
--- a/kernel/bpf/core.c
+++ b/kernel/bpf/core.c
@@ -1027,7 +1027,7 @@ bpf_jit_binary_alloc(unsigned int proglen, u8 **image_ptr,
hdr->size = size;
hole = min_t(unsigned int, size - (proglen + sizeof(*hdr)),
PAGE_SIZE - sizeof(*hdr));
- start = (get_random_int() % hole) & ~(alignment - 1);
+ start = prandom_u32_max(hole) & ~(alignment - 1);

/* Leave a random number of instructions before BPF code. */
*image_ptr = &hdr->image[start];
@@ -1089,7 +1089,7 @@ bpf_jit_binary_pack_alloc(unsigned int proglen, u8 **image_ptr,

hole = min_t(unsigned int, size - (proglen + sizeof(*ro_header)),
BPF_PROG_CHUNK_SIZE - sizeof(*ro_header));
- start = (get_random_int() % hole) & ~(alignment - 1);
+ start = prandom_u32_max(hole) & ~(alignment - 1);

*image_ptr = &ro_header->image[start];
*rw_image = &(*rw_header)->image[start];
diff --git a/kernel/locking/test-ww_mutex.c b/kernel/locking/test-ww_mutex.c
index 353004155d65..43efb2a04160 100644
--- a/kernel/locking/test-ww_mutex.c
+++ b/kernel/locking/test-ww_mutex.c
@@ -399,7 +399,7 @@ static int *get_random_order(int count)
order[n] = n;

for (n = count - 1; n > 1; n--) {
- r = get_random_int() % (n + 1);
+ r = prandom_u32_max(n + 1);
if (r != n) {
tmp = order[n];
order[n] = order[r];
@@ -538,7 +538,7 @@ static void stress_one_work(struct work_struct *work)
{
struct stress *stress = container_of(work, typeof(*stress), work);
const int nlocks = stress->nlocks;
- struct ww_mutex *lock = stress->locks + (get_random_int() % nlocks);
+ struct ww_mutex *lock = stress->locks + prandom_u32_max(nlocks);
int err;

do {
diff --git a/kernel/time/clocksource.c b/kernel/time/clocksource.c
index cee5da1e54c4..8058bec87ace 100644
--- a/kernel/time/clocksource.c
+++ b/kernel/time/clocksource.c
@@ -310,7 +310,7 @@ static void clocksource_verify_choose_cpus(void)
* CPUs that are currently online.
*/
for (i = 1; i < n; i++) {
- cpu = prandom_u32() % nr_cpu_ids;
+ cpu = prandom_u32_max(nr_cpu_ids);
cpu = cpumask_next(cpu - 1, cpu_online_mask);
if (cpu >= nr_cpu_ids)
cpu = cpumask_first(cpu_online_mask);
diff --git a/lib/cmdline_kunit.c b/lib/cmdline_kunit.c
index a72a2c16066e..e6a31c927b06 100644
--- a/lib/cmdline_kunit.c
+++ b/lib/cmdline_kunit.c
@@ -76,7 +76,7 @@ static void cmdline_test_lead_int(struct kunit *test)
int rc = cmdline_test_values[i];
int offset;

- sprintf(in, "%u%s", get_random_int() % 256, str);
+ sprintf(in, "%u%s", prandom_u32_max(256), str);
/* Only first '-' after the number will advance the pointer */
offset = strlen(in) - strlen(str) + !!(rc == 2);
cmdline_do_one_test(test, in, rc, offset);
@@ -94,7 +94,7 @@ static void cmdline_test_tail_int(struct kunit *test)
int rc = strcmp(str, "") ? (strcmp(str, "-") ? 0 : 1) : 1;
int offset;

- sprintf(in, "%s%u", str, get_random_int() % 256);
+ sprintf(in, "%s%u", str, prandom_u32_max(256));
/*
* Only first and leading '-' not followed by integer
* will advance the pointer.
diff --git a/lib/fault-inject.c b/lib/fault-inject.c
index 423784d9c058..96e092de5b72 100644
--- a/lib/fault-inject.c
+++ b/lib/fault-inject.c
@@ -139,7 +139,7 @@ bool should_fail(struct fault_attr *attr, ssize_t size)
return false;
}

- if (attr->probability <= prandom_u32() % 100)
+ if (attr->probability <= prandom_u32_max(100))
return false;

if (!fail_stacktrace(attr))
diff --git a/lib/find_bit_benchmark.c b/lib/find_bit_benchmark.c
index db904b57d4b8..1a6466c64bb6 100644
--- a/lib/find_bit_benchmark.c
+++ b/lib/find_bit_benchmark.c
@@ -157,8 +157,8 @@ static int __init find_bit_test(void)
bitmap_zero(bitmap2, BITMAP_LEN);

while (nbits--) {
- __set_bit(prandom_u32() % BITMAP_LEN, bitmap);
- __set_bit(prandom_u32() % BITMAP_LEN, bitmap2);
+ __set_bit(prandom_u32_max(BITMAP_LEN), bitmap);
+ __set_bit(prandom_u32_max(BITMAP_LEN), bitmap2);
}

test_find_next_bit(bitmap, BITMAP_LEN);
diff --git a/lib/reed_solomon/test_rslib.c b/lib/reed_solomon/test_rslib.c
index d9d1c33aebda..6faf9c9a6215 100644
--- a/lib/reed_solomon/test_rslib.c
+++ b/lib/reed_solomon/test_rslib.c
@@ -183,7 +183,7 @@ static int get_rcw_we(struct rs_control *rs, struct wspace *ws,

do {
/* Must not choose the same location twice */
- errloc = prandom_u32() % len;
+ errloc = prandom_u32_max(len);
} while (errlocs[errloc] != 0);

errlocs[errloc] = 1;
@@ -194,7 +194,7 @@ static int get_rcw_we(struct rs_control *rs, struct wspace *ws,
for (i = 0; i < eras; i++) {
do {
/* Must not choose the same location twice */
- errloc = prandom_u32() % len;
+ errloc = prandom_u32_max(len);
} while (errlocs[errloc] != 0);

derrlocs[i] = errloc;
diff --git a/lib/sbitmap.c b/lib/sbitmap.c
index 29eb0484215a..c4f04edf3ee9 100644
--- a/lib/sbitmap.c
+++ b/lib/sbitmap.c
@@ -33,7 +33,7 @@ static inline unsigned update_alloc_hint_before_get(struct sbitmap *sb,

hint = this_cpu_read(*sb->alloc_hint);
if (unlikely(hint >= depth)) {
- hint = depth ? prandom_u32() % depth : 0;
+ hint = depth ? prandom_u32_max(depth) : 0;
this_cpu_write(*sb->alloc_hint, hint);
}

diff --git a/lib/test-string_helpers.c b/lib/test-string_helpers.c
index 437d8e6b7cb1..86fadd3ba08c 100644
--- a/lib/test-string_helpers.c
+++ b/lib/test-string_helpers.c
@@ -587,7 +587,7 @@ static int __init test_string_helpers_init(void)
for (i = 0; i < UNESCAPE_ALL_MASK + 1; i++)
test_string_unescape("unescape", i, false);
test_string_unescape("unescape inplace",
- get_random_int() % (UNESCAPE_ANY + 1), true);
+ prandom_u32_max(UNESCAPE_ANY + 1), true);

/* Without dictionary */
for (i = 0; i < ESCAPE_ALL_MASK + 1; i++)
diff --git a/lib/test_hexdump.c b/lib/test_hexdump.c
index 5144899d3c6b..0927f44cd478 100644
--- a/lib/test_hexdump.c
+++ b/lib/test_hexdump.c
@@ -149,7 +149,7 @@ static void __init test_hexdump(size_t len, int rowsize, int groupsize,
static void __init test_hexdump_set(int rowsize, bool ascii)
{
size_t d = min_t(size_t, sizeof(data_b), rowsize);
- size_t len = get_random_int() % d + 1;
+ size_t len = prandom_u32_max(d) + 1;

test_hexdump(len, rowsize, 4, ascii);
test_hexdump(len, rowsize, 2, ascii);
@@ -208,11 +208,11 @@ static void __init test_hexdump_overflow(size_t buflen, size_t len,
static void __init test_hexdump_overflow_set(size_t buflen, bool ascii)
{
unsigned int i = 0;
- int rs = (get_random_int() % 2 + 1) * 16;
+ int rs = (prandom_u32_max(2) + 1) * 16;

do {
int gs = 1 << i;
- size_t len = get_random_int() % rs + gs;
+ size_t len = prandom_u32_max(rs) + gs;

test_hexdump_overflow(buflen, rounddown(len, gs), rs, gs, ascii);
} while (i++ < 3);
@@ -223,11 +223,11 @@ static int __init test_hexdump_init(void)
unsigned int i;
int rowsize;

- rowsize = (get_random_int() % 2 + 1) * 16;
+ rowsize = (prandom_u32_max(2) + 1) * 16;
for (i = 0; i < 16; i++)
test_hexdump_set(rowsize, false);

- rowsize = (get_random_int() % 2 + 1) * 16;
+ rowsize = (prandom_u32_max(2) + 1) * 16;
for (i = 0; i < 16; i++)
test_hexdump_set(rowsize, true);

diff --git a/lib/test_kasan.c b/lib/test_kasan.c
index 58c1b01ccfe2..7b4026623ace 100644
--- a/lib/test_kasan.c
+++ b/lib/test_kasan.c
@@ -1269,7 +1269,7 @@ static void match_all_not_assigned(struct kunit *test)
KASAN_TEST_NEEDS_CONFIG_OFF(test, CONFIG_KASAN_GENERIC);

for (i = 0; i < 256; i++) {
- size = (get_random_int() % 1024) + 1;
+ size = prandom_u32_max(1024) + 1;
ptr = kmalloc(size, GFP_KERNEL);
KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr);
KUNIT_EXPECT_GE(test, (u8)get_tag(ptr), (u8)KASAN_TAG_MIN);
@@ -1278,7 +1278,7 @@ static void match_all_not_assigned(struct kunit *test)
}

for (i = 0; i < 256; i++) {
- order = (get_random_int() % 4) + 1;
+ order = prandom_u32_max(4) + 1;
pages = alloc_pages(GFP_KERNEL, order);
ptr = page_address(pages);
KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr);
@@ -1291,7 +1291,7 @@ static void match_all_not_assigned(struct kunit *test)
return;

for (i = 0; i < 256; i++) {
- size = (get_random_int() % 1024) + 1;
+ size = prandom_u32_max(1024) + 1;
ptr = vmalloc(size);
KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr);
KUNIT_EXPECT_GE(test, (u8)get_tag(ptr), (u8)KASAN_TAG_MIN);
diff --git a/lib/test_list_sort.c b/lib/test_list_sort.c
index ade7a1ea0c8e..19ff229b9c3a 100644
--- a/lib/test_list_sort.c
+++ b/lib/test_list_sort.c
@@ -71,7 +71,7 @@ static void list_sort_test(struct kunit *test)
KUNIT_ASSERT_NOT_ERR_OR_NULL(test, el);

/* force some equivalencies */
- el->value = prandom_u32() % (TEST_LIST_LEN / 3);
+ el->value = prandom_u32_max(TEST_LIST_LEN / 3);
el->serial = i;
el->poison1 = TEST_POISON1;
el->poison2 = TEST_POISON2;
diff --git a/mm/migrate.c b/mm/migrate.c
index 6a1597c92261..db04f95fe050 100644
--- a/mm/migrate.c
+++ b/mm/migrate.c
@@ -2292,7 +2292,7 @@ int next_demotion_node(int node)
* caching issue, which seems more complicated. So selecting
* target node randomly seems better until now.
*/
- index = get_random_int() % target_nr;
+ index = prandom_u32_max(target_nr);
break;
}

diff --git a/mm/slub.c b/mm/slub.c
index 862dbd9af4f5..46ee52efeeef 100644
--- a/mm/slub.c
+++ b/mm/slub.c
@@ -1911,7 +1911,7 @@ static bool shuffle_freelist(struct kmem_cache *s, struct slab *slab)
return false;

freelist_count = oo_objects(s->oo);
- pos = get_random_int() % freelist_count;
+ pos = prandom_u32_max(freelist_count);

page_limit = slab->objects * s->size;
start = fixup_red_left(s, slab_address(slab));
diff --git a/net/ceph/mon_client.c b/net/ceph/mon_client.c
index 6a6898ee4049..db60217f911b 100644
--- a/net/ceph/mon_client.c
+++ b/net/ceph/mon_client.c
@@ -222,7 +222,7 @@ static void pick_new_mon(struct ceph_mon_client *monc)
max--;
}

- n = prandom_u32() % max;
+ n = prandom_u32_max(max);
if (o >= 0 && n >= o)
n++;

diff --git a/net/ceph/osd_client.c b/net/ceph/osd_client.c
index 87b883c7bfd6..4e4f1e4bc265 100644
--- a/net/ceph/osd_client.c
+++ b/net/ceph/osd_client.c
@@ -1479,7 +1479,7 @@ static bool target_should_be_paused(struct ceph_osd_client *osdc,

static int pick_random_replica(const struct ceph_osds *acting)
{
- int i = prandom_u32() % acting->size;
+ int i = prandom_u32_max(acting->size);

dout("%s picked osd%d, primary osd%d\n", __func__,
acting->osds[i], acting->primary);
diff --git a/net/core/neighbour.c b/net/core/neighbour.c
index 78cc8fb68814..85d497cb58d8 100644
--- a/net/core/neighbour.c
+++ b/net/core/neighbour.c
@@ -111,7 +111,7 @@ static void neigh_cleanup_and_release(struct neighbour *neigh)

unsigned long neigh_rand_reach_time(unsigned long base)
{
- return base ? (prandom_u32() % base) + (base >> 1) : 0;
+ return base ? prandom_u32_max(base) + (base >> 1) : 0;
}
EXPORT_SYMBOL(neigh_rand_reach_time);

diff --git a/net/core/pktgen.c b/net/core/pktgen.c
index 88906ba6d9a7..a13ee452429e 100644
--- a/net/core/pktgen.c
+++ b/net/core/pktgen.c
@@ -2324,7 +2324,7 @@ static inline int f_pick(struct pktgen_dev *pkt_dev)
pkt_dev->curfl = 0; /*reset */
}
} else {
- flow = prandom_u32() % pkt_dev->cflows;
+ flow = prandom_u32_max(pkt_dev->cflows);
pkt_dev->curfl = flow;

if (pkt_dev->flows[flow].count > pkt_dev->lflow) {
@@ -2380,10 +2380,9 @@ static void set_cur_queue_map(struct pktgen_dev *pkt_dev)
else if (pkt_dev->queue_map_min <= pkt_dev->queue_map_max) {
__u16 t;
if (pkt_dev->flags & F_QUEUE_MAP_RND) {
- t = prandom_u32() %
- (pkt_dev->queue_map_max -
- pkt_dev->queue_map_min + 1)
- + pkt_dev->queue_map_min;
+ t = prandom_u32_max(pkt_dev->queue_map_max -
+ pkt_dev->queue_map_min + 1) +
+ pkt_dev->queue_map_min;
} else {
t = pkt_dev->cur_queue_map + 1;
if (t > pkt_dev->queue_map_max)
@@ -2412,7 +2411,7 @@ static void mod_cur_headers(struct pktgen_dev *pkt_dev)
__u32 tmp;

if (pkt_dev->flags & F_MACSRC_RND)
- mc = prandom_u32() % pkt_dev->src_mac_count;
+ mc = prandom_u32_max(pkt_dev->src_mac_count);
else {
mc = pkt_dev->cur_src_mac_offset++;
if (pkt_dev->cur_src_mac_offset >=
@@ -2438,7 +2437,7 @@ static void mod_cur_headers(struct pktgen_dev *pkt_dev)
__u32 tmp;

if (pkt_dev->flags & F_MACDST_RND)
- mc = prandom_u32() % pkt_dev->dst_mac_count;
+ mc = prandom_u32_max(pkt_dev->dst_mac_count);

else {
mc = pkt_dev->cur_dst_mac_offset++;
@@ -2479,9 +2478,9 @@ static void mod_cur_headers(struct pktgen_dev *pkt_dev)

if (pkt_dev->udp_src_min < pkt_dev->udp_src_max) {
if (pkt_dev->flags & F_UDPSRC_RND)
- pkt_dev->cur_udp_src = prandom_u32() %
- (pkt_dev->udp_src_max - pkt_dev->udp_src_min)
- + pkt_dev->udp_src_min;
+ pkt_dev->cur_udp_src = prandom_u32_max(
+ pkt_dev->udp_src_max - pkt_dev->udp_src_min) +
+ pkt_dev->udp_src_min;

else {
pkt_dev->cur_udp_src++;
@@ -2492,9 +2491,9 @@ static void mod_cur_headers(struct pktgen_dev *pkt_dev)

if (pkt_dev->udp_dst_min < pkt_dev->udp_dst_max) {
if (pkt_dev->flags & F_UDPDST_RND) {
- pkt_dev->cur_udp_dst = prandom_u32() %
- (pkt_dev->udp_dst_max - pkt_dev->udp_dst_min)
- + pkt_dev->udp_dst_min;
+ pkt_dev->cur_udp_dst = prandom_u32_max(
+ pkt_dev->udp_dst_max - pkt_dev->udp_dst_min) +
+ pkt_dev->udp_dst_min;
} else {
pkt_dev->cur_udp_dst++;
if (pkt_dev->cur_udp_dst >= pkt_dev->udp_dst_max)
@@ -2509,7 +2508,7 @@ static void mod_cur_headers(struct pktgen_dev *pkt_dev)
if (imn < imx) {
__u32 t;
if (pkt_dev->flags & F_IPSRC_RND)
- t = prandom_u32() % (imx - imn) + imn;
+ t = prandom_u32_max(imx - imn) + imn;
else {
t = ntohl(pkt_dev->cur_saddr);
t++;
@@ -2531,8 +2530,8 @@ static void mod_cur_headers(struct pktgen_dev *pkt_dev)
if (pkt_dev->flags & F_IPDST_RND) {

do {
- t = prandom_u32() %
- (imx - imn) + imn;
+ t = prandom_u32_max(imx - imn) +
+ imn;
s = htonl(t);
} while (ipv4_is_loopback(s) ||
ipv4_is_multicast(s) ||
@@ -2579,9 +2578,9 @@ static void mod_cur_headers(struct pktgen_dev *pkt_dev)
if (pkt_dev->min_pkt_size < pkt_dev->max_pkt_size) {
__u32 t;
if (pkt_dev->flags & F_TXSIZE_RND) {
- t = prandom_u32() %
- (pkt_dev->max_pkt_size - pkt_dev->min_pkt_size)
- + pkt_dev->min_pkt_size;
+ t = prandom_u32_max(pkt_dev->max_pkt_size -
+ pkt_dev->min_pkt_size) +
+ pkt_dev->min_pkt_size;
} else {
t = pkt_dev->cur_pkt_size + 1;
if (t > pkt_dev->max_pkt_size)
@@ -2590,7 +2589,7 @@ static void mod_cur_headers(struct pktgen_dev *pkt_dev)
pkt_dev->cur_pkt_size = t;
} else if (pkt_dev->n_imix_entries > 0) {
struct imix_pkt *entry;
- __u32 t = prandom_u32() % IMIX_PRECISION;
+ __u32 t = prandom_u32_max(IMIX_PRECISION);
__u8 entry_index = pkt_dev->imix_distribution[t];

entry = &pkt_dev->imix_entries[entry_index];
diff --git a/net/core/stream.c b/net/core/stream.c
index ccc083cdef23..4780558ea314 100644
--- a/net/core/stream.c
+++ b/net/core/stream.c
@@ -123,7 +123,7 @@ int sk_stream_wait_memory(struct sock *sk, long *timeo_p)
DEFINE_WAIT_FUNC(wait, woken_wake_function);

if (sk_stream_memory_free(sk))
- current_timeo = vm_wait = (prandom_u32() % (HZ / 5)) + 2;
+ current_timeo = vm_wait = prandom_u32_max(HZ / 5) + 2;

add_wait_queue(sk_sleep(sk), &wait);

diff --git a/net/ipv4/igmp.c b/net/ipv4/igmp.c
index e3ab0cb61624..9149e78beea5 100644
--- a/net/ipv4/igmp.c
+++ b/net/ipv4/igmp.c
@@ -213,7 +213,7 @@ static void igmp_stop_timer(struct ip_mc_list *im)
/* It must be called with locked im->lock */
static void igmp_start_timer(struct ip_mc_list *im, int max_delay)
{
- int tv = prandom_u32() % max_delay;
+ int tv = prandom_u32_max(max_delay);

im->tm_running = 1;
if (!mod_timer(&im->timer, jiffies+tv+2))
@@ -222,7 +222,7 @@ static void igmp_start_timer(struct ip_mc_list *im, int max_delay)

static void igmp_gq_start_timer(struct in_device *in_dev)
{
- int tv = prandom_u32() % in_dev->mr_maxdelay;
+ int tv = prandom_u32_max(in_dev->mr_maxdelay);
unsigned long exp = jiffies + tv + 2;

if (in_dev->mr_gq_running &&
@@ -236,7 +236,7 @@ static void igmp_gq_start_timer(struct in_device *in_dev)

static void igmp_ifc_start_timer(struct in_device *in_dev, int delay)
{
- int tv = prandom_u32() % delay;
+ int tv = prandom_u32_max(delay);

if (!mod_timer(&in_dev->mr_ifc_timer, jiffies+tv+2))
in_dev_hold(in_dev);
diff --git a/net/ipv4/inet_connection_sock.c b/net/ipv4/inet_connection_sock.c
index eb31c7158b39..0c3eab1347cd 100644
--- a/net/ipv4/inet_connection_sock.c
+++ b/net/ipv4/inet_connection_sock.c
@@ -223,7 +223,7 @@ inet_csk_find_open_port(struct sock *sk, struct inet_bind_bucket **tb_ret, int *
if (likely(remaining > 1))
remaining &= ~1U;

- offset = prandom_u32() % remaining;
+ offset = prandom_u32_max(remaining);
/* __inet_hash_connect() favors ports having @low parity
* We do the opposite to not pollute connect() users.
*/
diff --git a/net/ipv6/addrconf.c b/net/ipv6/addrconf.c
index 10ce86bf228e..417834b7169d 100644
--- a/net/ipv6/addrconf.c
+++ b/net/ipv6/addrconf.c
@@ -104,7 +104,7 @@ static inline u32 cstamp_delta(unsigned long cstamp)
static inline s32 rfc3315_s14_backoff_init(s32 irt)
{
/* multiply 'initial retransmission time' by 0.9 .. 1.1 */
- u64 tmp = (900000 + prandom_u32() % 200001) * (u64)irt;
+ u64 tmp = (900000 + prandom_u32_max(200001)) * (u64)irt;
do_div(tmp, 1000000);
return (s32)tmp;
}
@@ -112,11 +112,11 @@ static inline s32 rfc3315_s14_backoff_init(s32 irt)
static inline s32 rfc3315_s14_backoff_update(s32 rt, s32 mrt)
{
/* multiply 'retransmission timeout' by 1.9 .. 2.1 */
- u64 tmp = (1900000 + prandom_u32() % 200001) * (u64)rt;
+ u64 tmp = (1900000 + prandom_u32_max(200001)) * (u64)rt;
do_div(tmp, 1000000);
if ((s32)tmp > mrt) {
/* multiply 'maximum retransmission time' by 0.9 .. 1.1 */
- tmp = (900000 + prandom_u32() % 200001) * (u64)mrt;
+ tmp = (900000 + prandom_u32_max(200001)) * (u64)mrt;
do_div(tmp, 1000000);
}
return (s32)tmp;
@@ -3967,7 +3967,7 @@ static void addrconf_dad_kick(struct inet6_ifaddr *ifp)
if (ifp->flags & IFA_F_OPTIMISTIC)
rand_num = 0;
else
- rand_num = prandom_u32() % (idev->cnf.rtr_solicit_delay ? : 1);
+ rand_num = prandom_u32_max(idev->cnf.rtr_solicit_delay ?: 1);

nonce = 0;
if (idev->cnf.enhanced_dad ||
diff --git a/net/ipv6/mcast.c b/net/ipv6/mcast.c
index 87c699d57b36..bf4f5edb3c3e 100644
--- a/net/ipv6/mcast.c
+++ b/net/ipv6/mcast.c
@@ -1050,7 +1050,7 @@ bool ipv6_chk_mcast_addr(struct net_device *dev, const struct in6_addr *group,
/* called with mc_lock */
static void mld_gq_start_work(struct inet6_dev *idev)
{
- unsigned long tv = prandom_u32() % idev->mc_maxdelay;
+ unsigned long tv = prandom_u32_max(idev->mc_maxdelay);

idev->mc_gq_running = 1;
if (!mod_delayed_work(mld_wq, &idev->mc_gq_work, tv + 2))
@@ -1068,7 +1068,7 @@ static void mld_gq_stop_work(struct inet6_dev *idev)
/* called with mc_lock */
static void mld_ifc_start_work(struct inet6_dev *idev, unsigned long delay)
{
- unsigned long tv = prandom_u32() % delay;
+ unsigned long tv = prandom_u32_max(delay);

if (!mod_delayed_work(mld_wq, &idev->mc_ifc_work, tv + 2))
in6_dev_hold(idev);
@@ -1085,7 +1085,7 @@ static void mld_ifc_stop_work(struct inet6_dev *idev)
/* called with mc_lock */
static void mld_dad_start_work(struct inet6_dev *idev, unsigned long delay)
{
- unsigned long tv = prandom_u32() % delay;
+ unsigned long tv = prandom_u32_max(delay);

if (!mod_delayed_work(mld_wq, &idev->mc_dad_work, tv + 2))
in6_dev_hold(idev);
@@ -1130,7 +1130,7 @@ static void igmp6_group_queried(struct ifmcaddr6 *ma, unsigned long resptime)
}

if (delay >= resptime)
- delay = prandom_u32() % resptime;
+ delay = prandom_u32_max(resptime);

if (!mod_delayed_work(mld_wq, &ma->mca_work, delay))
refcount_inc(&ma->mca_refcnt);
@@ -2574,7 +2574,7 @@ static void igmp6_join_group(struct ifmcaddr6 *ma)

igmp6_send(&ma->mca_addr, ma->idev->dev, ICMPV6_MGM_REPORT);

- delay = prandom_u32() % unsolicited_report_interval(ma->idev);
+ delay = prandom_u32_max(unsolicited_report_interval(ma->idev));

if (cancel_delayed_work(&ma->mca_work)) {
refcount_dec(&ma->mca_refcnt);
diff --git a/net/netfilter/ipvs/ip_vs_twos.c b/net/netfilter/ipvs/ip_vs_twos.c
index acb55d8393ef..f2579fc9c75b 100644
--- a/net/netfilter/ipvs/ip_vs_twos.c
+++ b/net/netfilter/ipvs/ip_vs_twos.c
@@ -71,8 +71,8 @@ static struct ip_vs_dest *ip_vs_twos_schedule(struct ip_vs_service *svc,
* from 0 to total_weight
*/
total_weight += 1;
- rweight1 = prandom_u32() % total_weight;
- rweight2 = prandom_u32() % total_weight;
+ rweight1 = prandom_u32_max(total_weight);
+ rweight2 = prandom_u32_max(total_weight);

/* Pick two weighted servers */
list_for_each_entry_rcu(dest, &svc->destinations, n_list) {
diff --git a/net/packet/af_packet.c b/net/packet/af_packet.c
index 5cbe07116e04..331f80e12779 100644
--- a/net/packet/af_packet.c
+++ b/net/packet/af_packet.c
@@ -1350,7 +1350,7 @@ static bool fanout_flow_is_huge(struct packet_sock *po, struct sk_buff *skb)
if (READ_ONCE(history[i]) == rxhash)
count++;

- victim = prandom_u32() % ROLLOVER_HLEN;
+ victim = prandom_u32_max(ROLLOVER_HLEN);

/* Avoid dirtying the cache line if possible */
if (READ_ONCE(history[victim]) != rxhash)
diff --git a/net/sched/act_gact.c b/net/sched/act_gact.c
index ac29d1065232..1accaedef54f 100644
--- a/net/sched/act_gact.c
+++ b/net/sched/act_gact.c
@@ -26,7 +26,7 @@ static struct tc_action_ops act_gact_ops;
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)
+ if (prandom_u32_max(gact->tcfg_pval))
return gact->tcf_action;
return gact->tcfg_paction;
}
diff --git a/net/sched/act_sample.c b/net/sched/act_sample.c
index 2f7f5e44d28c..55c9f961fb0f 100644
--- a/net/sched/act_sample.c
+++ b/net/sched/act_sample.c
@@ -169,7 +169,7 @@ static int tcf_sample_act(struct sk_buff *skb, const struct tc_action *a,
psample_group = rcu_dereference_bh(s->psample_group);

/* randomly sample packets according to rate */
- if (psample_group && (prandom_u32() % s->rate == 0)) {
+ if (psample_group && (prandom_u32_max(s->rate) == 0)) {
if (!skb_at_tc_ingress(skb)) {
md.in_ifindex = skb->skb_iif;
md.out_ifindex = skb->dev->ifindex;
diff --git a/net/sched/sch_netem.c b/net/sched/sch_netem.c
index 5449ed114e40..3ca320f1a031 100644
--- a/net/sched/sch_netem.c
+++ b/net/sched/sch_netem.c
@@ -513,8 +513,8 @@ static int netem_enqueue(struct sk_buff *skb, struct Qdisc *sch,
goto finish_segs;
}

- skb->data[prandom_u32() % skb_headlen(skb)] ^=
- 1<<(prandom_u32() % 8);
+ skb->data[prandom_u32_max(skb_headlen(skb))] ^=
+ 1<<prandom_u32_max(8);
}

if (unlikely(sch->q.qlen >= sch->limit)) {
diff --git a/net/sctp/socket.c b/net/sctp/socket.c
index 171f1a35d205..1e354ba44960 100644
--- a/net/sctp/socket.c
+++ b/net/sctp/socket.c
@@ -8319,7 +8319,7 @@ static int sctp_get_port_local(struct sock *sk, union sctp_addr *addr)

inet_get_local_port_range(net, &low, &high);
remaining = (high - low) + 1;
- rover = prandom_u32() % remaining + low;
+ rover = prandom_u32_max(remaining) + low;

do {
rover++;
diff --git a/net/tipc/socket.c b/net/tipc/socket.c
index f1c3b8eb4b3d..e902b01ea3cb 100644
--- a/net/tipc/socket.c
+++ b/net/tipc/socket.c
@@ -3010,7 +3010,7 @@ static int tipc_sk_insert(struct tipc_sock *tsk)
struct net *net = sock_net(sk);
struct tipc_net *tn = net_generic(net, tipc_net_id);
u32 remaining = (TIPC_MAX_PORT - TIPC_MIN_PORT) + 1;
- u32 portid = prandom_u32() % remaining + TIPC_MIN_PORT;
+ u32 portid = prandom_u32_max(remaining) + TIPC_MIN_PORT;

while (remaining--) {
portid++;
diff --git a/net/xfrm/xfrm_state.c b/net/xfrm/xfrm_state.c
index 91c32a3b6924..b213c89cfb8a 100644
--- a/net/xfrm/xfrm_state.c
+++ b/net/xfrm/xfrm_state.c
@@ -2072,7 +2072,7 @@ int xfrm_alloc_spi(struct xfrm_state *x, u32 low, u32 high)
} else {
u32 spi = 0;
for (h = 0; h < high-low+1; h++) {
- spi = low + prandom_u32()%(high-low+1);
+ spi = low + prandom_u32_max(high - low + 1);
x0 = xfrm_state_lookup(net, mark, &x->id.daddr, htonl(spi), x->id.proto, x->props.family);
if (x0 == NULL) {
newspi = htonl(spi);
--
2.37.3