linux/drivers/net/wireless/ath/ath12k/p2p.c
Yu-Hsiang Tseng 4498664e2d wifi: ath12k: use lockdep_assert_in_rcu_read_lock() for RCU assertions
Two functions in ath12k assert that the caller holds an RCU read lock:
ath12k_mac_get_arvif() and ath12k_p2p_noa_update_vdev_iter(). Both use:

    WARN_ON(!rcu_read_lock_any_held());

On kernels using preemptible RCU (CONFIG_PREEMPT=y or CONFIG_PREEMPT_RT=y)
without CONFIG_DEBUG_LOCK_ALLOC, this produces a false positive splat
whenever these functions are invoked from paths that do hold the RCU
read lock (e.g. firmware stats processing or mac80211 interface
iteration).

Root cause:

  - Without CONFIG_DEBUG_LOCK_ALLOC, rcu_read_lock_any_held() is a
    static inline that returns !preemptible() as a proxy for "in an
    RCU read section".

  - With preemptible RCU, rcu_read_lock() does not disable preemption.
    A task can therefore be preemptible while legitimately holding an
    RCU read lock, making the proxy unreliable.

  - Callers such as ath12k_wmi_tlv_rssi_chain_parse() (via guard(rcu)())
    and ieee80211_iterate_active_interfaces_atomic() do hold the RCU
    read lock, so these warnings are incorrect.

Typical splat seen on a WCN7850 station with periodic fw stats
processing:

  WARNING: drivers/net/wireless/ath/ath12k/mac.c:791 at
    ath12k_mac_get_arvif+0x9e/0xd0 [ath12k]
  Tainted: G W O 6.19.13-rt #1 PREEMPT_RT
  Call Trace:
   ath12k_wmi_tlv_rssi_chain_parse+0x69/0x170 [ath12k]
   ath12k_wmi_tlv_iter+0x7f/0x120 [ath12k]
   ath12k_wmi_tlv_fw_stats_parse+0x342/0x6b0 [ath12k]
   ath12k_wmi_op_rx+0xe9e/0x3150 [ath12k]
   ath12k_htc_rx_completion_handler+0x3df/0x5b0 [ath12k]
   ath12k_ce_per_engine_service+0x325/0x3e0 [ath12k]
   ath12k_pci_ce_workqueue+0x20/0x40 [ath12k]

Replace WARN_ON(!rcu_read_lock_any_held()) with
lockdep_assert_in_rcu_read_lock(), which is gated on CONFIG_PROVE_RCU
and therefore compiles out entirely when PROVE_RCU is disabled.
PROVE_RCU kernels continue to get the full lockdep-based check, and
the new helper precisely checks for rcu_read_lock() rather than any
RCU variant, which better matches the callers' expectations.

Tested-on: WCN7850 hw2.0 PCI WLAN.HMT.1.1.c5-00302-QCAHMTSWPL_V1.0_V2.0_SILICONZ-1.115823.3

Fixes: 3dd2c68f20 ("wifi: ath12k: prepare vif data structure for MLO handling")
Suggested-by: Baochen Qiang <baochen.qiang@oss.qualcomm.com>
Suggested-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Reviewed-by: Baochen Qiang <baochen.qiang@oss.qualcomm.com>
Reviewed-by: Rameshkumar Sundaram <rameshkumar.sundaram@oss.qualcomm.com>
Signed-off-by: Yu-Hsiang Tseng <asas1asas200@gmail.com>
Reviewed-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Link: https://patch.msgid.link/20260422180814.1938317-1-asas1asas200@gmail.com
Signed-off-by: Jeff Johnson <jeff.johnson@oss.qualcomm.com>
2026-04-23 10:57:50 -07:00

148 lines
4.0 KiB
C

// SPDX-License-Identifier: BSD-3-Clause-Clear
/*
* Copyright (c) 2024 Qualcomm Innovation Center, Inc. All rights reserved.
* Copyright (c) Qualcomm Technologies, Inc. and/or its subsidiaries.
*/
#include <net/mac80211.h>
#include "core.h"
#include "mac.h"
#include "p2p.h"
static void ath12k_p2p_noa_ie_fill(u8 *data, size_t len,
const struct ath12k_wmi_p2p_noa_info *noa)
{
struct ieee80211_p2p_noa_attr *noa_attr;
u8 ctwindow = le32_get_bits(noa->noa_attr, WMI_P2P_NOA_INFO_CTWIN_TU);
bool oppps = le32_get_bits(noa->noa_attr, WMI_P2P_NOA_INFO_OPP_PS);
__le16 *noa_attr_len;
u16 attr_len;
u8 noa_descriptors = le32_get_bits(noa->noa_attr,
WMI_P2P_NOA_INFO_DESC_NUM);
int i;
/* P2P IE */
data[0] = WLAN_EID_VENDOR_SPECIFIC;
data[1] = len - 2;
data[2] = (WLAN_OUI_WFA >> 16) & 0xff;
data[3] = (WLAN_OUI_WFA >> 8) & 0xff;
data[4] = (WLAN_OUI_WFA >> 0) & 0xff;
data[5] = WLAN_OUI_TYPE_WFA_P2P;
/* NOA ATTR */
data[6] = IEEE80211_P2P_ATTR_ABSENCE_NOTICE;
noa_attr_len = (__le16 *)&data[7]; /* 2 bytes */
noa_attr = (struct ieee80211_p2p_noa_attr *)&data[9];
noa_attr->index = le32_get_bits(noa->noa_attr,
WMI_P2P_NOA_INFO_INDEX);
noa_attr->oppps_ctwindow = ctwindow;
if (oppps)
noa_attr->oppps_ctwindow |= IEEE80211_P2P_OPPPS_ENABLE_BIT;
for (i = 0; i < noa_descriptors; i++) {
noa_attr->desc[i].count =
__le32_to_cpu(noa->descriptors[i].type_count);
noa_attr->desc[i].duration = noa->descriptors[i].duration;
noa_attr->desc[i].interval = noa->descriptors[i].interval;
noa_attr->desc[i].start_time = noa->descriptors[i].start_time;
}
attr_len = 2; /* index + oppps_ctwindow */
attr_len += noa_descriptors * sizeof(struct ieee80211_p2p_noa_desc);
*noa_attr_len = __cpu_to_le16(attr_len);
}
static size_t ath12k_p2p_noa_ie_len_compute(const struct ath12k_wmi_p2p_noa_info *noa)
{
size_t len = 0;
if (!(le32_get_bits(noa->noa_attr, WMI_P2P_NOA_INFO_DESC_NUM)) &&
!(le32_get_bits(noa->noa_attr, WMI_P2P_NOA_INFO_OPP_PS)))
return 0;
len += 1 + 1 + 4; /* EID + len + OUI */
len += 1 + 2; /* noa attr + attr len */
len += 1 + 1; /* index + oppps_ctwindow */
len += le32_get_bits(noa->noa_attr, WMI_P2P_NOA_INFO_DESC_NUM) *
sizeof(struct ieee80211_p2p_noa_desc);
return len;
}
static void ath12k_p2p_noa_ie_assign(struct ath12k_link_vif *arvif, void *ie,
size_t len)
{
struct ath12k *ar = arvif->ar;
lockdep_assert_held(&ar->data_lock);
kfree(arvif->ahvif->u.ap.noa_data);
arvif->ahvif->u.ap.noa_data = ie;
arvif->ahvif->u.ap.noa_len = len;
}
static void __ath12k_p2p_noa_update(struct ath12k_link_vif *arvif,
const struct ath12k_wmi_p2p_noa_info *noa)
{
struct ath12k *ar = arvif->ar;
void *ie;
size_t len;
lockdep_assert_held(&ar->data_lock);
ath12k_p2p_noa_ie_assign(arvif, NULL, 0);
len = ath12k_p2p_noa_ie_len_compute(noa);
if (!len)
return;
ie = kmalloc(len, GFP_ATOMIC);
if (!ie)
return;
ath12k_p2p_noa_ie_fill(ie, len, noa);
ath12k_p2p_noa_ie_assign(arvif, ie, len);
}
void ath12k_p2p_noa_update(struct ath12k_link_vif *arvif,
const struct ath12k_wmi_p2p_noa_info *noa)
{
struct ath12k *ar = arvif->ar;
spin_lock_bh(&ar->data_lock);
__ath12k_p2p_noa_update(arvif, noa);
spin_unlock_bh(&ar->data_lock);
}
static void ath12k_p2p_noa_update_vdev_iter(void *data, u8 *mac,
struct ieee80211_vif *vif)
{
struct ath12k_vif *ahvif = ath12k_vif_to_ahvif(vif);
struct ath12k_p2p_noa_arg *arg = data;
struct ath12k_link_vif *arvif;
lockdep_assert_in_rcu_read_lock();
arvif = &ahvif->deflink;
if (!arvif->is_created || arvif->ar != arg->ar || arvif->vdev_id != arg->vdev_id)
return;
ath12k_p2p_noa_update(arvif, arg->noa);
}
void ath12k_p2p_noa_update_by_vdev_id(struct ath12k *ar, u32 vdev_id,
const struct ath12k_wmi_p2p_noa_info *noa)
{
struct ath12k_p2p_noa_arg arg = {
.vdev_id = vdev_id,
.ar = ar,
.noa = noa,
};
ieee80211_iterate_active_interfaces_atomic(ath12k_ar_to_hw(ar),
IEEE80211_IFACE_ITER_NORMAL,
ath12k_p2p_noa_update_vdev_iter,
&arg);
}