From: "Gustavo A. R. Silva" <gustavo@embeddedor.com>
To: Felix Fietkau <nbd@nbd.name>,
Lorenzo Bianconi <lorenzo.bianconi83@gmail.com>,
Kalle Valo <kvalo@codeaurora.org>,
"David S. Miller" <davem@davemloft.net>,
Matthias Brugger <matthias.bgg@gmail.com>
Cc: linux-wireless@vger.kernel.org, netdev@vger.kernel.org,
linux-arm-kernel@lists.infradead.org,
linux-mediatek@lists.infradead.org, linux-kernel@vger.kernel.org,
"Gustavo A. R. Silva" <gustavo@embeddedor.com>
Subject: [mt76/mt7603/mac] Question about missing variable assignment
Date: Sat, 2 Mar 2019 15:10:46 -0600 [thread overview]
Message-ID: <20190302211046.GA20268@embeddedor.com> (raw)
Hi all,
The following piece of code in drivers/net/wireless/mediatek/mt76/mt7603/mac.c
is missing a variable assignment before line 1058. Notice that there
is a potential execution path in which variable *i* is compared against
magic number 15 at line 1075 without being initialized previously
(this was reported by Coverity):
1055 out:
1056 final_rate_flags = info->status.rates[final_idx].flags;
1057
1058 switch (FIELD_GET(MT_TX_RATE_MODE, final_rate)) {
1059 case MT_PHY_TYPE_CCK:
1060 cck = true;
1061 /* fall through */
1062 case MT_PHY_TYPE_OFDM:
1063 if (dev->mt76.chandef.chan->band == NL80211_BAND_5GHZ)
1064 sband = &dev->mt76.sband_5g.sband;
1065 else
1066 sband = &dev->mt76.sband_2g.sband;
1067 final_rate &= GENMASK(5, 0);
1068 final_rate = mt7603_get_rate(dev, sband, final_rate, cck);
1069 final_rate_flags = 0;
1070 break;
1071 case MT_PHY_TYPE_HT_GF:
1072 case MT_PHY_TYPE_HT:
1073 final_rate_flags |= IEEE80211_TX_RC_MCS;
1074 final_rate &= GENMASK(5, 0);
1075 if (i > 15)
1076 return false;
1077 break;
1078 default:
1079 return false;
1080 }
My guess is that such missing assignment should be something similar
to the one at line 566:
i = FIELD_GET(MT_RXV1_TX_RATE, rxdg0);
but I'm not sure what the proper arguments for macro FIELD_GET should
be.
This code was introduced by commit c8846e1015022d2531ac4c895783e400b3e5babe
What do you think?
Thanks
--
Gustavo
next reply other threads:[~2019-03-02 21:32 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-03-02 21:10 Gustavo A. R. Silva [this message]
2019-03-03 10:05 ` [mt76/mt7603/mac] Question about missing variable assignment Felix Fietkau
2019-03-03 15:06 ` Gustavo A. R. Silva
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