From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mgamail.intel.com (mgamail.intel.com [198.175.65.12]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id E5F071F8ACA; Fri, 3 Oct 2025 14:03:05 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=198.175.65.12 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1759500187; cv=none; b=dbFbLAL5ue7npSh3DMdFHDm7sszHfIro5ZcwLvOKqFJ5tD02BIHzfKz7Rr954yseN+9BbLDkUE6A0/EQcwSrdN7ivz5ND0WIfqTypywdSGmQyroWy648Q0IQGQfOwaKQ3gMnS6FkmMDC+eGss95BRANmc3VaVS3kGwNx0Q5wIv8= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1759500187; c=relaxed/simple; bh=eqJWymf6BKvUMuphEGUgcMTaSTyldrF7JMSr19bWKtQ=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=t8lk1UjVXlhWj5aKEdJwJYZKqLoyn/DCGOYcQ25Y5saUyFfIG1d26jZUkwXKiNMVD50+8qSDMyFztSSPWnwiytVSpLkd1h/onrNTVii/cn5WZLaITnlOyXDPIMu7voNacdDJoLewHHLBEQRzHQMUqcPV3WFalsgqaDsZMx17sRY= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=intel.com; spf=pass smtp.mailfrom=intel.com; dkim=pass (2048-bit key) header.d=intel.com header.i=@intel.com header.b=CmDPOsbN; arc=none smtp.client-ip=198.175.65.12 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=intel.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=intel.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=intel.com header.i=@intel.com header.b="CmDPOsbN" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1759500186; x=1791036186; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=eqJWymf6BKvUMuphEGUgcMTaSTyldrF7JMSr19bWKtQ=; b=CmDPOsbN/fsT8Ifxr6LdDpfrXMsYNwEP8MGBuHHzZB3U3y4X6KNMA797 eufQtNDkAd86IyaqVkRk2G3YPvugiROp8mWqe594SXIpooeKIdwPmEFga G4D/5WHm6vK/7gOlcfP2WhSMmHjlmy0amElAmeH3k10jY36Cbv4PXjeeO kCzX/aFpgseQc5AVjvVns2bcocQTPyEAk15230FLDYjGF4AgaYectgBdi EZwCBDbQShDrwFm0Gnh37V2sMVmkZ0Hbb9EfseP+fyQKydOq5nyBjjn7y rGDXkl1uazA6ueDW4WgYG8FErNFG1AcJDJU3dRY79/mVoBFDO51ti6tU2 w==; X-CSE-ConnectionGUID: zBfmBj5MTfq6aLokScAFSg== X-CSE-MsgGUID: rcIFgfFiRMijVZRVUe8IDw== X-IronPort-AV: E=McAfee;i="6800,10657,11571"; a="73210312" X-IronPort-AV: E=Sophos;i="6.18,312,1751266800"; d="scan'208";a="73210312" Received: from orviesa004.jf.intel.com ([10.64.159.144]) by orvoesa104.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 03 Oct 2025 07:03:06 -0700 X-CSE-ConnectionGUID: ZYtXLopnRpeKZtR8oPiFlA== X-CSE-MsgGUID: otEboiR7Qai+DeFUeQz59Q== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="6.18,312,1751266800"; d="scan'208";a="183580155" Received: from boxer.igk.intel.com ([10.102.20.173]) by orviesa004.jf.intel.com with ESMTP; 03 Oct 2025 07:03:03 -0700 From: Maciej Fijalkowski To: bpf@vger.kernel.org, ast@kernel.org, daniel@iogearbox.net, hawk@kernel.org, ilias.apalodimas@linaro.org, toke@redhat.com, lorenzo@kernel.org Cc: netdev@vger.kernel.org, magnus.karlsson@intel.com, andrii@kernel.org, stfomichev@gmail.com, aleksander.lobakin@intel.com, Maciej Fijalkowski Subject: [PATCH bpf 2/2] veth: update mem type in xdp_buff Date: Fri, 3 Oct 2025 16:02:43 +0200 Message-Id: <20251003140243.2534865-3-maciej.fijalkowski@intel.com> X-Mailer: git-send-email 2.38.1 In-Reply-To: <20251003140243.2534865-1-maciej.fijalkowski@intel.com> References: <20251003140243.2534865-1-maciej.fijalkowski@intel.com> Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Veth calls skb_pp_cow_data() which makes the underlying memory to originate from system page_pool. For CONFIG_DEBUG_VM=y and XDP program that uses bpf_xdp_adjust_tail(), following splat was observed: [ 32.204881] BUG: Bad page state in process test_progs pfn:11c98b [ 32.207167] page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x11c98b [ 32.210084] flags: 0x1fffe0000000000(node=0|zone=1|lastcpupid=0x7fff) [ 32.212493] raw: 01fffe0000000000 dead000000000040 ff11000123c9b000 0000000000000000 [ 32.218056] raw: 0000000000000000 0000000000000001 00000000ffffffff 0000000000000000 [ 32.220900] page dumped because: page_pool leak [ 32.222636] Modules linked in: bpf_testmod(O) bpf_preload [ 32.224632] CPU: 6 UID: 0 PID: 3612 Comm: test_progs Tainted: G O 6.17.0-rc5-gfec474d29325 #6969 PREEMPT [ 32.224638] Tainted: [O]=OOT_MODULE [ 32.224639] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.14.0-0-g155821a1990b-prebuilt.qemu.org 04/01/2014 [ 32.224641] Call Trace: [ 32.224644] [ 32.224646] dump_stack_lvl+0x4b/0x70 [ 32.224653] bad_page.cold+0xbd/0xe0 [ 32.224657] __free_frozen_pages+0x838/0x10b0 [ 32.224660] ? skb_pp_cow_data+0x782/0xc30 [ 32.224665] bpf_xdp_shrink_data+0x221/0x530 [ 32.224668] ? skb_pp_cow_data+0x6d1/0xc30 [ 32.224671] bpf_xdp_adjust_tail+0x598/0x810 [ 32.224673] ? xsk_destruct_skb+0x321/0x800 [ 32.224678] bpf_prog_004ac6bb21de57a7_xsk_xdp_adjust_tail+0x52/0xd6 [ 32.224681] veth_xdp_rcv_skb+0x45d/0x15a0 [ 32.224684] ? get_stack_info_noinstr+0x16/0xe0 [ 32.224688] ? veth_set_channels+0x920/0x920 [ 32.224691] ? get_stack_info+0x2f/0x80 [ 32.224693] ? unwind_next_frame+0x3af/0x1df0 [ 32.224697] veth_xdp_rcv.constprop.0+0x38a/0xbe0 [ 32.224700] ? common_startup_64+0x13e/0x148 [ 32.224703] ? veth_xdp_rcv_one+0xcd0/0xcd0 [ 32.224706] ? stack_trace_save+0x84/0xa0 [ 32.224709] ? stack_depot_save_flags+0x28/0x820 [ 32.224713] ? __resched_curr.constprop.0+0x332/0x3b0 [ 32.224716] ? timerqueue_add+0x217/0x320 [ 32.224719] veth_poll+0x115/0x5e0 [ 32.224722] ? veth_xdp_rcv.constprop.0+0xbe0/0xbe0 [ 32.224726] ? update_load_avg+0x1cb/0x12d0 [ 32.224730] ? update_cfs_group+0x121/0x2c0 [ 32.224733] __napi_poll+0xa0/0x420 [ 32.224736] net_rx_action+0x901/0xe90 [ 32.224740] ? run_backlog_napi+0x50/0x50 [ 32.224743] ? clockevents_program_event+0x1cc/0x280 [ 32.224746] ? hrtimer_interrupt+0x31e/0x7c0 [ 32.224749] handle_softirqs+0x151/0x430 [ 32.224752] do_softirq+0x3f/0x60 [ 32.224755] It's because xdp_rxq with mem model set to MEM_TYPE_PAGE_SHARED was used when initializing xdp_buff. Fix this by using new helper xdp_update_mem_type() that will check if page used for linear part of xdp_buff comes from page_pool. We assume that linear data and frags will have same memory provider as currently XDP API does not provide us a way to distinguish it (the mem model is registered for *whole* Rx queue and here we speak about single buffer granularity). Fixes: 0ebab78cbcbf ("net: veth: add page_pool for page recycling") Reported-by: Alexei Starovoitov Closes: https://lore.kernel.org/bpf/CAADnVQ+bBofJDfieyOYzSmSujSfJwDTQhiz3aJw7hE+4E2_iPA@mail.gmail.com/ Signed-off-by: Maciej Fijalkowski --- drivers/net/veth.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/drivers/net/veth.c b/drivers/net/veth.c index a3046142cb8e..2ccc40e57d12 100644 --- a/drivers/net/veth.c +++ b/drivers/net/veth.c @@ -814,6 +814,8 @@ static struct sk_buff *veth_xdp_rcv_skb(struct veth_rq *rq, orig_data = xdp->data; orig_data_end = xdp->data_end; + xdp_update_mem_type(xdp); + act = bpf_prog_run_xdp(xdp_prog, xdp); switch (act) { -- 2.43.0