[PATCH 5.18 0016/1095] wifi: mac80211_hwsim: use 32-bit skb cookie

Greg Kroah-Hartman
2022-08-15T20:07:12Z

From: Johannes Berg <johannes.berg@intel.com>

commit cc5250cdb43d444061412df7fae72d2b4acbdf97 upstream.

We won't really have enough skbs to need a 64-bit cookie,
and on 32-bit platforms storing the 64-bit cookie into the
void *rate_driver_data doesn't work anyway. Switch back to
using just a 32-bit cookie and uintptr_t for the type to
avoid compiler warnings about all this.

Fixes: 4ee186fa7e40 ("wifi: mac80211_hwsim: fix race condition in pending packet")
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Cc: Jeongik Cha <jeongik@google.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
drivers/net/wireless/mac80211_hwsim.c | 10 +++++-----
1 file changed, 5 insertions(+), 5 deletions(-)

--- a/drivers/net/wireless/mac80211_hwsim.c
+++ b/drivers/net/wireless/mac80211_hwsim.c
@@ -680,7 +680,7 @@ struct mac80211_hwsim_data {
bool ps_poll_pending;
struct dentry *debugfs;

- atomic64_t pending_cookie;
+ atomic_t pending_cookie;
struct sk_buff_head pending; /* packets pending */
/*
* Only radios in the same group can communicate together (the
@@ -1347,7 +1347,7 @@ static void mac80211_hwsim_tx_frame_nl(s
int i;
struct hwsim_tx_rate tx_attempts[IEEE80211_TX_MAX_RATES];
struct hwsim_tx_rate_flag tx_attempts_flags[IEEE80211_TX_MAX_RATES];
- u64 cookie;
+ uintptr_t cookie;

if (data->ps != PS_DISABLED)
hdr->frame_control |= cpu_to_le16(IEEE80211_FCTL_PM);
@@ -1416,7 +1416,7 @@ static void mac80211_hwsim_tx_frame_nl(s
goto nla_put_failure;

/* We create a cookie to identify this skb */
- cookie = (u64)atomic64_inc_return(&data->pending_cookie);
+ cookie = atomic_inc_return(&data->pending_cookie);
info->rate_driver_data[0] = (void *)cookie;
if (nla_put_u64_64bit(skb, HWSIM_ATTR_COOKIE, cookie, HWSIM_ATTR_PAD))
goto nla_put_failure;
@@ -4109,10 +4109,10 @@ static int hwsim_tx_info_frame_received_
/* look for the skb matching the cookie passed back from user */
spin_lock_irqsave(&data2->pending.lock, flags);
skb_queue_walk_safe(&data2->pending, skb, tmp) {
- u64 skb_cookie;
+ uintptr_t skb_cookie;

txi = IEEE80211_SKB_CB(skb);
- skb_cookie = (u64)(uintptr_t)txi->rate_driver_data[0];
+ skb_cookie = (uintptr_t)txi->rate_driver_data[0];

if (skb_cookie == ret_skb_cookie) {
__skb_unlink(skb, &data2->pending);