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From:   Ramya Gnanasekar <quic_rgnanase@quicinc.com>
To:     ath12k@lists.infradead.org
Cc:     linux-wireless@vger.kernel.org,
        Ramya Gnanasekar <quic_rgnanase@quicinc.com>
Subject: [PATCH] wifi: ath12k: Handle lock during peer_id find
Date:   Sun, 22 Jan 2023 07:19:36 +0530
Message-Id: <20230122014936.3594-1-quic_rgnanase@quicinc.com>
Precedence: bulk

ath12k_peer_find_by_id() requires that the caller hold the
ab->base_lock. Currently the WBM error path does not hold
the lock and calling that function, leads to the
following lockdep_assert()in QCN9274:

[105162.160893] ------------[ cut here ]------------
[105162.160916] WARNING: CPU: 3 PID: 0 at drivers/net/wireless/ath/ath12k/peer.c:71 ath12k_peer_find_by_id+0x52/0x60 [ath12k]
[105162.160933] Modules linked in: ath12k(O) qrtr_mhi qrtr mac80211 cfg80211 mhi qmi_helpers libarc4 nvme nvme_core [last unloaded: ath12k(O)]
[105162.160967] CPU: 3 PID: 0 Comm: swapper/3 Tainted: G        W  O       6.1.0-rc2+ #3
[105162.160972] Hardware name: Intel(R) Client Systems NUC8i7HVK/NUC8i7HVB, BIOS HNKBLi70.86A.0056.2019.0506.1527 05/06/2019
[105162.160977] RIP: 0010:ath12k_peer_find_by_id+0x52/0x60 [ath12k]
[105162.160990] Code: 07 eb 0f 39 68 24 74 0a 48 8b 00 48 39 f8 75 f3 31 c0 5b 5d c3 48 8d bf b0 f2 00 00 be ff ff ff ff e8 22 20 c4 e2 85 c0 75 bf <0f> 0b eb bb 66 2e 0f 1f 84 00 00 00 00 00 41 54 4c 8d a7 98 f2 00
[105162.160996] RSP: 0018:ffffa223001acc60 EFLAGS: 00010246
[105162.161003] RAX: 0000000000000000 RBX: ffff9f0573940000 RCX: 0000000000000000
[105162.161008] RDX: 0000000000000001 RSI: ffffffffa3951c8e RDI: ffffffffa39a96d7
[105162.161013] RBP: 000000000000000a R08: 0000000000000000 R09: 0000000000000000
[105162.161017] R10: ffffa223001acb40 R11: ffffffffa3d57c60 R12: ffff9f057394f2e0
[105162.161022] R13: ffff9f0573940000 R14: ffff9f04ecd659c0 R15: ffff9f04d5a9b040
[105162.161026] FS:  0000000000000000(0000) GS:ffff9f0575600000(0000) knlGS:0000000000000000
[105162.161031] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[105162.161036] CR2: 00001d5c8277a008 CR3: 00000001e6224006 CR4: 00000000003706e0
[105162.161041] Call Trace:
[105162.161046]  <IRQ>
[105162.161051]  ath12k_dp_rx_process_wbm_err+0x6da/0xaf0 [ath12k]
[105162.161072]  ? ath12k_dp_rx_process_err+0x80e/0x15a0 [ath12k]
[105162.161084]  ? __lock_acquire+0x4ca/0x1a60
[105162.161104]  ath12k_dp_service_srng+0x263/0x310 [ath12k]
[105162.161120]  ath12k_pci_ext_grp_napi_poll+0x1c/0x70 [ath12k]
[105162.161133]  __napi_poll+0x22/0x260
[105162.161141]  net_rx_action+0x2f8/0x380
[105162.161153]  __do_softirq+0xd0/0x4c9
[105162.161162]  irq_exit_rcu+0x88/0xe0
[105162.161169]  common_interrupt+0xa5/0xc0
[105162.161174]  </IRQ>
[105162.161179]  <TASK>
[105162.161184]  asm_common_interrupt+0x22/0x40

Handle spin lock/unlock in WBM error path to hold the necessary lock
expected by ath12k_peer_find_by_id().

Tested-on: QCN9274 hw2.0 PCI WLAN.WBE.1.0-03171-QCAHKSWPL_SILICONZ-1

Signed-off-by: Ramya Gnanasekar <quic_rgnanase@quicinc.com>

diff --git a/drivers/net/wireless/ath/ath12k/dp_rx.c b/drivers/net/wireless/ath/ath12k/dp_rx.c
index d6835d13f7ec..c0efdd76d291 100644
--- a/drivers/net/wireless/ath/ath12k/dp_rx.c
+++ b/drivers/net/wireless/ath/ath12k/dp_rx.c
@@ -3495,11 +3495,14 @@ static int ath12k_dp_rx_h_null_q_desc(struct ath12k *ar, struct sk_buff *msdu,
 	msdu_len = ath12k_dp_rx_h_msdu_len(ab, desc);
 	peer_id = ath12k_dp_rx_h_peer_id(ab, desc);
 
+	spin_lock(&ab->base_lock);
 	if (!ath12k_peer_find_by_id(ab, peer_id)) {
+		spin_unlock(&ab->base_lock);
 		ath12k_dbg(ab, ATH12K_DBG_DATA, "invalid peer id received in wbm err pkt%d\n",
 			   peer_id);
 		return -EINVAL;
 	}
+	spin_unlock(&ab->base_lock);
 
 	if (!rxcb->is_frag && ((msdu_len + hal_rx_desc_sz) > DP_RX_BUFFER_SIZE)) {
 		/* First buffer will be freed by the caller, so deduct it's length */
-- 
2.17.1