treewide: use get_random_u32_inclusive() when possible

These cases were done with this Coccinelle:

@@
expression H;
expression L;
@@
- (get_random_u32_below(H) + L)
+ get_random_u32_inclusive(L, H + L - 1)

@@
expression H;
expression L;
expression E;
@@
  get_random_u32_inclusive(L,
  H
- + E
- - E
  )

@@
expression H;
expression L;
expression E;
@@
  get_random_u32_inclusive(L,
  H
- - E
- + E
  )

@@
expression H;
expression L;
expression E;
expression F;
@@
  get_random_u32_inclusive(L,
  H
- - E
  + F
- + E
  )

@@
expression H;
expression L;
expression E;
expression F;
@@
  get_random_u32_inclusive(L,
  H
- + E
  + F
- - E
  )

And then subsequently cleaned up by hand, with several automatic cases
rejected if it didn't make sense contextually.

Reviewed-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com> # for infiniband
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>

8 files changed, 12 insertions, 13 deletions

diff --git a/drivers/bus/mhi/host/internal.h b/drivers/bus/mhi/host/internal.h
index c73621aabbd1..2e139e76de4c 100644
--- a/drivers/bus/mhi/host/internal.h
+++ b/drivers/bus/mhi/host/internal.h
@@ -129,7 +129,7 @@ enum mhi_pm_state {
 #define PRIMARY_CMD_RING				0
 #define MHI_DEV_WAKE_DB					127
 #define MHI_MAX_MTU					0xffff
-#define MHI_RANDOM_U32_NONZERO(bmsk)			(get_random_u32_below(bmsk) + 1)
+#define MHI_RANDOM_U32_NONZERO(bmsk)			(get_random_u32_inclusive(1, bmsk))
 
 enum mhi_er_type {
 	MHI_ER_TYPE_INVALID = 0x0,
diff --git a/drivers/dma-buf/st-dma-fence-chain.c b/drivers/dma-buf/st-dma-fence-chain.c
index 9fbad7317d9b..c0979c8049b5 100644
--- a/drivers/dma-buf/st-dma-fence-chain.c
+++ b/drivers/dma-buf/st-dma-fence-chain.c
@@ -400,7 +400,7 @@ static int __find_race(void *arg)
 		struct dma_fence *fence = dma_fence_get(data->fc.tail);
 		int seqno;
 
-		seqno = get_random_u32_below(data->fc.chain_length) + 1;
+		seqno = get_random_u32_inclusive(1, data->fc.chain_length);
 
 		err = dma_fence_chain_find_seqno(&fence, seqno);
 		if (err) {
diff --git a/drivers/infiniband/core/cma.c b/drivers/infiniband/core/cma.c
index dd1c703b10df..aacd6254df77 100644
--- a/drivers/infiniband/core/cma.c
+++ b/drivers/infiniband/core/cma.c
@@ -3807,7 +3807,7 @@ 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 = get_random_u32_below(remaining) + low;
+	rover = get_random_u32_inclusive(low, remaining + low - 1);
 retry:
 	if (last_used_port != rover) {
 		struct rdma_bind_list *bind_list;
diff --git a/drivers/infiniband/hw/hns/hns_roce_ah.c b/drivers/infiniband/hw/hns/hns_roce_ah.c
index b37d2a81584d..e77fcc74f15c 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_below(IB_ROCE_UDP_ENCAP_VALID_PORT_MAX +
-					     1 - IB_ROCE_UDP_ENCAP_VALID_PORT_MIN) +
-			IB_ROCE_UDP_ENCAP_VALID_PORT_MIN;
+		sport = get_random_u32_inclusive(IB_ROCE_UDP_ENCAP_VALID_PORT_MIN,
+						 IB_ROCE_UDP_ENCAP_VALID_PORT_MAX);
 	else
 		sport = rdma_flow_label_to_udp_sport(fl);
 
diff --git a/drivers/mtd/nand/raw/nandsim.c b/drivers/mtd/nand/raw/nandsim.c
index 274a31b93100..c21abf748948 100644
--- a/drivers/mtd/nand/raw/nandsim.c
+++ b/drivers/mtd/nand/raw/nandsim.c
@@ -1405,7 +1405,7 @@ static void ns_do_bit_flips(struct nandsim *ns, int num)
 	if (bitflips && get_random_u16() < (1 << 6)) {
 		int flips = 1;
 		if (bitflips > 1)
-			flips = get_random_u32_below(bitflips) + 1;
+			flips = get_random_u32_inclusive(1, bitflips);
 		while (flips--) {
 			int pos = get_random_u32_below(num * 8);
 			ns->buf.byte[pos / 8] ^= (1 << (pos % 8));
diff --git a/drivers/net/wireguard/selftest/allowedips.c b/drivers/net/wireguard/selftest/allowedips.c
index 78a916f30c82..78ebe2892a78 100644
--- a/drivers/net/wireguard/selftest/allowedips.c
+++ b/drivers/net/wireguard/selftest/allowedips.c
@@ -285,7 +285,7 @@ static __init bool randomized_test(void)
 
 	for (i = 0; i < NUM_RAND_ROUTES; ++i) {
 		get_random_bytes(ip, 4);
-		cidr = get_random_u32_below(32) + 1;
+		cidr = get_random_u32_inclusive(1, 32);
 		peer = peers[get_random_u32_below(NUM_PEERS)];
 		if (wg_allowedips_insert_v4(&t, (struct in_addr *)ip, cidr,
 					    peer, &mutex) < 0) {
@@ -311,7 +311,7 @@ static __init bool randomized_test(void)
 				mutated[k] = (mutated[k] & mutate_mask[k]) |
 					     (~mutate_mask[k] &
 					      get_random_u8());
-			cidr = get_random_u32_below(32) + 1;
+			cidr = get_random_u32_inclusive(1, 32);
 			peer = peers[get_random_u32_below(NUM_PEERS)];
 			if (wg_allowedips_insert_v4(&t,
 						    (struct in_addr *)mutated,
@@ -329,7 +329,7 @@ static __init bool randomized_test(void)
 
 	for (i = 0; i < NUM_RAND_ROUTES; ++i) {
 		get_random_bytes(ip, 16);
-		cidr = get_random_u32_below(128) + 1;
+		cidr = get_random_u32_inclusive(1, 128);
 		peer = peers[get_random_u32_below(NUM_PEERS)];
 		if (wg_allowedips_insert_v6(&t, (struct in6_addr *)ip, cidr,
 					    peer, &mutex) < 0) {
@@ -355,7 +355,7 @@ static __init bool randomized_test(void)
 				mutated[k] = (mutated[k] & mutate_mask[k]) |
 					     (~mutate_mask[k] &
 					      get_random_u8());
-			cidr = get_random_u32_below(128) + 1;
+			cidr = get_random_u32_inclusive(1, 128);
 			peer = peers[get_random_u32_below(NUM_PEERS)];
 			if (wg_allowedips_insert_v6(&t,
 						    (struct in6_addr *)mutated,
diff --git a/drivers/net/wireless/broadcom/brcm80211/brcmfmac/p2p.c b/drivers/net/wireless/broadcom/brcm80211/brcmfmac/p2p.c
index 23c971b77965..c704ca752138 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 + get_random_u32_below(3)));
+						100 * get_random_u32_inclusive(1, 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 1696fbf1009a..3a7a44bb3c60 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 = get_random_u32_below(64 - 36) + 36;
+			u32 rand = get_random_u32_inclusive(36, 63);
 			mvmvif->ap_beacon_time = data.beacon_device_ts +
 				ieee80211_tu_to_usec(data.beacon_int * rand /
 						     100);