From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.remote-ip=74.125.82.197 ARC-Seal: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; cv=none; t=1794176992; b=LBbzdxtkKwXBc2TnFZgQp35wzobqdGnJ/3LyKwfM24t2JpMNhXkApi79vAu2pdcQFLQ3 FBLoWykKu9fp7h4vO1loESZ7WYuNatJyfgmzPa5ARaIvqEbsacOVs16KB+K/7kPrvSXY3 PWsxN1dyE9X92ccGWoYjD5XLZl/jkayPK+pcpUOS7qivoJiBMelPDZWUmq1jPwNlgcBei qUr/txeO2gkFhW38/oT5JYwGeroPcp7SkPS548Pu8OFq8g0BM0i0UFdA/2QacDbhrf5bO yYwMj2ZmJc29nC5BWHQEw8V8IsUH6QkLlXpCAyoZMj4SSjSK+WWfAmF05RJ5V+jjx2Q== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1794176992; h=DMARC-Filter:Received:DKIM-Signature:X-Google-DKIM-Signature: X-Forwarded-Encrypted:X-Gm-Message-State:X-Received:Date:Mime-Version: X-Mailer:Message-ID:Subject:From:To:Cc:Content-Type; bh=s8BbK2IqWwoRejKoPp8MQhqTOQlps2N83qEGGaCE+Ow=; b=A23yjhiIA4rT+MRtWGjYg1UBjra7Ulg+gBiz/TYj2cn5sg+NJrLvGpo8f6hDAAEpACz2 VvTJBP3ANDQuTLyZu4236g91aZLMLxgBDmR6/Ffvs23SBjoHYO5g2gJGvVd92gDsIvzSx C8CTUD9YZdLcwMRyrwlIDkmdJocnGdV9bbbcpZyuFeYUpC/G8BXH63AMhYQ2piBTzm/t8 KSHoQtTDmHszkquH2Owne3g/+YlcQ3Go1WIWjmWdogO69YIdmod1uCapsem8gYJ4D/uyp rjUvsJ3YjzZYIhS6CkAbsNGWp44bNhLeJ+fWPxCvQF6Yc1QzvmQuJ4p6v3qs3jGRJuw== ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass header.from=google.com; spf=pass smtp.mailfrom=flex--bcochrane.bounces.google.com; dkim=pass header.d=google.com header.i=@google.com header.a=rsa-sha256 header.s=20260707 header.b=k3eQvj2x; arc=none smtp.remote-ip=74.125.82.197 Received: from mail-dy1-f197.google.com (mail-dy1-f197.google.com [74.125.82.197]) (using TLSv1.3 with cipher TLS_AES_128_GCM_SHA256 (128/128 bits) key-exchange X25519 server-signature ECDSA (prime256v1) server-digest SHA256) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 88CC5606A320 for ; Sun, 8 Nov 2026 22:29:51 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.2 smtp.subspace.kernel.org 88CC5606A320 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=google.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=flex--bcochrane.bounces.google.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.a=rsa-sha256 header.s=20260707 header.b=k3eQvj2x Received: by mail-dy1-f197.google.com with SMTP id 5a478bee46e88-341eff9e381so782375eec.1 for ; Sun, 08 Nov 2026 14:29:51 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20260707; t=1794176991; x=1794781791; darn=vger.kernel.org; h=content-type:cc:to:from:subject:message-id:mime-version:date:from :to:cc:subject:date:message-id:reply-to:content-type; bh=s8BbK2IqWwoRejKoPp8MQhqTOQlps2N83qEGGaCE+Ow=; b=k3eQvj2x+t5skfzGZz5GyhPzMfETyB1pjsBDgldrz41P6bij1l4h+dyR0LpzW+Z1Gz FHC4SqrM+DvuiHdbW8MG8Sqyxm/LTR8Pp1Zz8rhjVlOtO+QobGW5HCIDeNdZvk4Ae7nx rMSGfR0ErQpX4PczfQ9B+sX1XMhFzOb79qL/F7kzfsoCkIeUGhygrJgOJnXCmCAVTf/9 P5pTdXauu4I7TTS5jKim94sDvriL2kh1fom4M91Il+PJ0MTBzyDt4aU4wguLoBG8QDvJ F7yfZ18kxoDDH53jAKAuLZlg9MefNyQodaK88XLig4O+ustzI9at/Ejat7DKRxDxQR04 wZvw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20260707; t=1794176991; x=1794781791; h=content-type:cc:to:from:subject:message-id:mime-version:date :x-gm-message-state:from:to:cc:subject:date:message-id:reply-to :content-type; bh=s8BbK2IqWwoRejKoPp8MQhqTOQlps2N83qEGGaCE+Ow=; b=beVLRBJme6yu4OBibyf7mTgxLwUFzAZvJP+iF7V1ACm/+5mGJFkh+yVlBzRtG4LWCm zUVenaamRRlfRPxWsnPsqlVvO0mRoC/URo3ICgom8lVRhiNoZ/Utk4McYkk5+ed7GhaE ZGqTaeID2u7yefOE/vu1Epnuhe0MDGtX8KDn2ctkxtru2LT7s4b/zXy/t5BzPlZ7tUSy Fl5dYYRgeLVNuDbBPJ3vo2cpCv7G601EFpEQRljXYtw9VUEX+sUoDNIAT3ee7nl4yFy+ CKjU0+yE5u8LSeKvz0hyP3kLUIEi5W05ceiuc2oga+NaCXPY3CN/QaUqFaBfIEA/MbNR Q1Ng== X-Forwarded-Encrypted: i=1; AL+hErH0lGWi27U3Tga7Y58Km3O3xphbWy6Pr1/ZGUtqKIsvMFt2m8THHR4Nj1mClaFLtIZMFLpGT9w=@vger.kernel.org X-Gm-Message-State: APuU4Z8baTb3jW+kEJ+44GUdAuWWRSqmaxyZh/PReXj+EO9zAR55t7mJ tPzRNB7Yvp8uYd1kge/lqUIgDp5dCRU/6TcE5rLnzzQJWygWN2MMJUioRnRzFx7ZlKRTEmAOPDd JBvAq5Y75/6hD/X0c8Q== X-Received: from dybtt4.prod.google.com ([2002:a05:7300:f404:b0:36d:c15d:8d80]) (user=bcochrane job=prod-delivery.src-stubby-dispatcher) by 2002:a05:7301:6199:10b0:36f:29bf:4326 with SMTP id 5a478bee46e88-37250fdd781mr5143821eec.0.1794176990371; Sun, 08 Nov 2026 14:29:50 -0800 (PST) Date: Sun, 8 Nov 2026 14:29:42 -0800 X-Mailing-List: netdev@vger.kernel.org List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list Mime-Version: 1.0 X-Mailer: git-send-email 2.56.0.542.g3ef89b7020-goog Message-ID: <20261108222942.1233295-1-bcochrane@google.com> Subject: [PATCH net v4] bnxt_en: Take RTNL before netif_close() when aborting FW reset From: Bryan Cochrane To: Michael Chan , Pavan Chebbi , netdev@vger.kernel.org Cc: Andrew Lunn , "David S . Miller" , Eric Dumazet , Jakub Kicinski , Paolo Abeni , Stanislav Fomichev , Joe Damato , linux-kernel@vger.kernel.org, Bryan Cochrane , stable@vger.kernel.org Content-Type: text/plain; charset="UTF-8" netif_close() must be called with RTNL held in addition to the netdev instance lock: __dev_close_many() asserts it, and the NETDEV_GOING_DOWN and NETDEV_DOWN notifier chains it runs rely on it for serialization. Commit 004b5008016a ("eth: bnxt: remove most dependencies on RTNL") replaced rtnl_lock() with netdev_lock() in bnxt_fw_reset_task() and bnxt_fw_reset(). That is sufficient for the paths that only tear the NIC down internally with __bnxt_close_nic(), but the abort paths close the netdev via bnxt_fw_reset_abort() -> netif_close(), and the error path in bnxt_fw_reset() calls netif_close() directly. Those now run without RTNL and trigger a WARN_ONCE() cascade when a firmware reset is aborted: RTNL: assertion failed at net/core/dev.c (1740) WARNING: net/core/dev.c:1740 at __dev_close_many+0x1be/0x1f0 Workqueue: bnxt_pf_wq bnxt_fw_reset_task [bnxt_en] Call Trace: netif_close_many+0xb5/0x190 netif_close+0xa2/0xd0 bnxt_fw_reset_task.cold+0x8d/0x213 [bnxt_en] process_one_work+0x19d/0x3a0 worker_thread+0x1af/0x320 kthread+0xe3/0x120 followed by the same assertion from call_netdevice_notifiers_info(), fib_rules_event(), inetdev_event(), rtnl_fill_ifinfo(), devlink_compat_phys_port_name_get() and ip_mc_down(). This was observed on a machine in real use with a BCM57504 (4 PFs, FW 236.1.153.0) running v7.1.6: the firmware crashed, announced a "Fatal firmware reset event" and then failed to come back within the advertised max wait, so bnxt_fw_reset_task() aborted the reset on all ports: bnxt_en 0000:c1:00.1 eno16905np1: Firmware reset aborted bnxt_en 0000:c1:00.1 eno16905np1: fw_health_status 0x448100 Take RTNL (before the netdev instance lock, matching the OPENING state which already uses rtnl_trylock()) in the fw_reset_abort path of bnxt_fw_reset_task() and route the POLL_VF abort through that same path. In bnxt_fw_reset(), only the bnxt_get_registered_vfs() error path needs RTNL: drop the instance lock, reacquire RTNL and the instance lock via bnxt_rtnl_lock_sp(), then clear BNXT_STATE_IN_FW_RESET and close the device synchronously. The normal reset flow, which may run on many VFs at the same time, keeps running without RTNL. Because bnxt_fw_reset() and bnxt_fw_exception() can also be entered from devlink process context via bnxt_fw_recover(), guard the BNXT_STATE_IN_SP_TASK bit manipulation in bnxt_[rtnl_]lock_sp() and bnxt_[rtnl_]unlock_sp() with current_work() == &bp->sp_task. Otherwise a concurrent devlink health recover backing off during the unlock window would set BNXT_STATE_IN_SP_TASK with no sp_task running to clear it, causing the subsequent __bnxt_close_nic() busy-wait to hang. The bug was found by inspecting the kernel log of the affected machine and the driver source; the fix was prepared with the help of an AI coding assistant (Gemini based) and reviewed by the submitter. It is build tested (allmodconfig with W=1, plus the same change on top of v7.1.6 built as a module for the affected BCM57504 host). The aborted reset path itself only runs when the firmware fails to return from a reset, which could not be reproduced on demand. Fixes: 004b5008016a ("eth: bnxt: remove most dependencies on RTNL") Cc: stable@vger.kernel.org Signed-off-by: Bryan Cochrane --- v4: - Return to the synchronous close in bnxt_fw_reset() from v2, using netdev_unlock() + bnxt_rtnl_lock_sp() as suggested by Michael Chan, and guard BNXT_STATE_IN_SP_TASK in bnxt_[rtnl_]lock_sp() and bnxt_[rtnl_]unlock_sp() with current_work() == &bp->sp_task. Deferring the close to bnxt_fw_reset_task() in v3 still hung when entered via bnxt_fw_recover(), raced with bnxt_hwrm_if_change() clearing fw_reset_state, and marked the reporter SEVERITY_FATAL (reported by the netdev Sashiko review). - Omitted Michael's Reviewed-by and Stanislav's Acked-by from v2 due to the new bnxt_in_sp_task() check. v3: https://lore.kernel.org/netdev/20261104045534.79783-1-bcochrane@google.com/ - Do not drop and retake the locks in bnxt_fw_reset(). Route the bnxt_get_registered_vfs() failure through the bnxt_fw_reset_task() abort path instead; this also restarts the ULP after that abort. The v2 unlock/relock window let a concurrent devlink health recover set BNXT_STATE_IN_SP_TASK via bnxt_unlock_sp() and hang the close (reported by the netdev Sashiko review). v2: https://lore.kernel.org/netdev/20261103042210.2984373-1-bcochrane@google.com/ - Keep bnxt_lock_sp() in bnxt_fw_reset() and take RTNL only on the bnxt_get_registered_vfs() error path, to avoid RTNL contention when many VFs recover at the same time (Michael Chan). - Dropped Stanislav's Acked-by because of the change above. v1: https://lore.kernel.org/netdev/20261029032832.1511180-1-bcochrane@google.com/ drivers/net/ethernet/broadcom/bnxt/bnxt.c | 31 ++++++++++++++++------- 1 file changed, 22 insertions(+), 9 deletions(-) diff --git a/drivers/net/ethernet/broadcom/bnxt/bnxt.c b/drivers/net/ethernet/broadcom/bnxt/bnxt.c index 33c4cacc8ffe..7a2b96f56464 100644 --- a/drivers/net/ethernet/broadcom/bnxt/bnxt.c +++ b/drivers/net/ethernet/broadcom/bnxt/bnxt.c @@ -14575,35 +14575,44 @@ static void bnxt_timer(struct timer_list *t) mod_timer(&bp->timer, jiffies + bp->current_interval); } +static bool bnxt_in_sp_task(struct bnxt *bp) +{ + return current_work() == &bp->sp_task; +} + static void bnxt_lock_sp(struct bnxt *bp) { - /* We are called from bnxt_sp_task which has BNXT_STATE_IN_SP_TASK - * set. If the device is being closed, bnxt_close() may be holding + /* If we are called from bnxt_sp_task, BNXT_STATE_IN_SP_TASK is set. + * If the device is being closed, bnxt_close() may be holding * netdev instance lock and waiting for BNXT_STATE_IN_SP_TASK to clear. * So we must clear BNXT_STATE_IN_SP_TASK before holding netdev * instance lock. */ - clear_bit(BNXT_STATE_IN_SP_TASK, &bp->state); + if (bnxt_in_sp_task(bp)) + clear_bit(BNXT_STATE_IN_SP_TASK, &bp->state); netdev_lock(bp->dev); } static void bnxt_unlock_sp(struct bnxt *bp) { - set_bit(BNXT_STATE_IN_SP_TASK, &bp->state); + if (bnxt_in_sp_task(bp)) + set_bit(BNXT_STATE_IN_SP_TASK, &bp->state); netdev_unlock(bp->dev); } /* Same as bnxt_lock_sp() with additional rtnl_lock */ static void bnxt_rtnl_lock_sp(struct bnxt *bp) { - clear_bit(BNXT_STATE_IN_SP_TASK, &bp->state); + if (bnxt_in_sp_task(bp)) + clear_bit(BNXT_STATE_IN_SP_TASK, &bp->state); rtnl_lock(); netdev_lock(bp->dev); } static void bnxt_rtnl_unlock_sp(struct bnxt *bp) { - set_bit(BNXT_STATE_IN_SP_TASK, &bp->state); + if (bnxt_in_sp_task(bp)) + set_bit(BNXT_STATE_IN_SP_TASK, &bp->state); netdev_unlock(bp->dev); rtnl_unlock(); } @@ -14860,9 +14869,12 @@ void bnxt_fw_reset(struct bnxt *bp) if (n < 0) { netdev_err(bp->dev, "Firmware reset aborted, rc = %d\n", n); + netdev_unlock(bp->dev); + bnxt_rtnl_lock_sp(bp); clear_bit(BNXT_STATE_IN_FW_RESET, &bp->state); netif_close(bp->dev); - goto fw_reset_exit; + bnxt_rtnl_unlock_sp(bp); + return; } else if (n > 0) { u16 vf_tmo_dsecs = n * 10; @@ -15547,9 +15559,8 @@ static void bnxt_fw_reset_task(struct work_struct *work) bp->fw_reset_timestamp = jiffies; netdev_lock(bp->dev); if (test_bit(BNXT_STATE_ABORT_ERR, &bp->state)) { - bnxt_fw_reset_abort(bp, rc); netdev_unlock(bp->dev); - goto ulp_start; + goto fw_reset_abort; } bnxt_fw_reset_close(bp); if (bp->fw_cap & BNXT_FW_CAP_ERR_RECOVER_RELOAD) { @@ -15682,9 +15693,11 @@ static void bnxt_fw_reset_task(struct work_struct *work) netdev_err(bp->dev, "fw_health_status 0x%x\n", sts); } fw_reset_abort: + rtnl_lock(); netdev_lock(bp->dev); bnxt_fw_reset_abort(bp, rc); netdev_unlock(bp->dev); + rtnl_unlock(); ulp_start: if (!rc) bnxt_ulp_start(bp); base-commit: 30c71476d842b094651bd7712f6c8ee8716147d0 -- 2.56.0.542.g3ef89b7020-goog