From mboxrd@z Thu Jan 1 00:00:00 1970 From: James Hughes Subject: [PATCH v2] brcmfmac: Make skb header writable before use Date: Mon, 24 Apr 2017 14:03:22 +0100 Message-ID: <20170424130322.476-1-james.hughes@raspberrypi.org> Cc: James Hughes To: Arend van Spriel , Franky Lin , Hante Meuleman , Kalle Valo , linux-wireless@vger.kernel.org, brcm80211-dev-list.pdl@broadcom.com, netdev@vger.kernel.org Return-path: Received: from mx07-00252a01.pphosted.com ([62.209.51.214]:9826 "EHLO mx07-00252a01.pphosted.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S934111AbdDXNDf (ORCPT ); Mon, 24 Apr 2017 09:03:35 -0400 Received: from pps.filterd (m0102628.ppops.net [127.0.0.1]) by mx07-00252a01.pphosted.com (8.16.0.20/8.16.0.20) with SMTP id v3OD1PRt022361 for ; Mon, 24 Apr 2017 14:03:34 +0100 Received: from mail-wm0-f71.google.com (mail-wm0-f71.google.com [74.125.82.71]) by mx07-00252a01.pphosted.com with ESMTP id 29yvjys2wm-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128 verify=OK) for ; Mon, 24 Apr 2017 14:03:33 +0100 Received: by mail-wm0-f71.google.com with SMTP id n198so4697028wmg.9 for ; Mon, 24 Apr 2017 06:03:33 -0700 (PDT) Sender: netdev-owner@vger.kernel.org List-ID: The driver was making changes to the skb_header without ensuring it was writable (i.e. uncloned). This patch also removes some boiler plate header size checking/adjustment code as that is also handled by the skb_cow_header function used to make header writable. This patch depends on brcmfmac: Ensure pointer correctly set if skb data location changes Signed-off-by: James Hughes --- Changes in v2 Makes the _cow_ call at the entry point of the skb in to the stack, means only needs to be done once, and error handling is easier. Split a separate minor bug fix off to a separate patch (which this patch depends on) .../net/wireless/broadcom/brcm80211/brcmfmac/core.c | 19 ++++--------------- 1 file changed, 4 insertions(+), 15 deletions(-) diff --git a/drivers/net/wireless/broadcom/brcm80211/brcmfmac/core.c b/drivers/net/wireless/broadcom/brcm80211/brcmfmac/core.c index 9b7c19a508ac..88f8675a94c2 100644 --- a/drivers/net/wireless/broadcom/brcm80211/brcmfmac/core.c +++ b/drivers/net/wireless/broadcom/brcm80211/brcmfmac/core.c @@ -211,22 +211,11 @@ static netdev_tx_t brcmf_netdev_start_xmit(struct sk_buff *skb, goto done; } - /* Make sure there's enough room for any header */ - if (skb_headroom(skb) < drvr->hdrlen) { - struct sk_buff *skb2; - - brcmf_dbg(INFO, "%s: insufficient headroom\n", - brcmf_ifname(ifp)); - drvr->bus_if->tx_realloc++; - skb2 = skb_realloc_headroom(skb, drvr->hdrlen); + /* Make sure there's enough room for any header, and make it writable */ + if (skb_cow_head(skb, drvr->hdrlen)) { dev_kfree_skb(skb); - skb = skb2; - if (skb == NULL) { - brcmf_err("%s: skb_realloc_headroom failed\n", - brcmf_ifname(ifp)); - ret = -ENOMEM; - goto done; - } + ret = -ENOMEM; + goto done; } /* validate length for ether packet */ -- 2.11.0