Path: csiph.com!eternal-september.org!feeder.eternal-september.org!aioe.org!bofh.it!news.nic.it!robomod From: Rasmus Villemoes Newsgroups: linux.kernel Subject: [PATCH] qeth: don't rely on signedness of char Date: Sat, 05 Dec 2015 22:40:02 +0100 Message-ID: X-Original-To: Ursula Braun , Martin Schwidefsky , Heiko Carstens Dkim-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=rasmusvillemoes.dk; s=google; h=from:to:cc:subject:date:message-id; bh=UX/t2J7RtrGssxOJjttTLyNkatLFNMEzPZtJy1kETT4=; b=F3sH73nNfvPpongbFHvxFXAbnn5sijuf6z5PFRAJJ7MvrXJpxlWoEXpQD0gUcYuJC8 7B38bZCmcRLchZhtF0bhtdcIx+cEDaHR12WLc7aI2/PL3BzY/+O6zAO0I0ZtlQCPBW6j L/233SyXofop6kTxlVThGl6VMFT1XB39uT9Ew= X-Google-Dkim-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20130820; h=x-gm-message-state:from:to:cc:subject:date:message-id; bh=UX/t2J7RtrGssxOJjttTLyNkatLFNMEzPZtJy1kETT4=; b=d1jcYe+OdFqt5AVIC9M9k8uyV6l8rO2kzrPgWOVvg7n1UhcH7rwTxYARcxtVj7CBq0 RqI7uHbSZ5o880PxShoiRjAeHNKy99lrkg63F436NVVjD/J6mLaqKrt72VDIMJI2pH4L nDgvcKgxt4omKGfwty/1oYxLlwTh4Md6m5mNf0f632dHRmv/0B8avOzgdeqozphU/1bR 8kFTYs1NktrUJyTwWbMhvMh9MUyjcma4pc2hPfb+qdMD/HqmVAmYPQP29dGbUH85jVLV JlVLtKprO0RgS4x+Rh67laXfpVyuHpJzAa4UNtXMohLrQRt3WRIvjQ3rp+ued060qgup RXCA== X-Gm-Message-State: ALoCoQkBEj2xvYf5gQSd3ku/PTbdSq5EDI7myZ9DscYC1MZkX2TmHW/dIRXNq9+uTNXWyXyZzKHS X-Received: by 10.25.161.78 with SMTP id k75mr9198720lfe.31.1449351193449; Sat, 05 Dec 2015 13:33:13 -0800 (PST) X-Mailer: git-send-email 2.6.1 Sender: robomod@news.nic.it List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Approved: robomod@news.nic.it Lines: 41 Organization: linux.* mail to news gateway X-Original-Cc: Rasmus Villemoes , linux-s390@vger.kernel.org, linux-kernel@vger.kernel.org X-Original-Date: Sat, 5 Dec 2015 22:32:52 +0100 X-Original-Message-ID: <1449351173-6915-1-git-send-email-linux@rasmusvillemoes.dk> X-Original-Sender: linux-kernel-owner@vger.kernel.org Xref: csiph.com linux.kernel:1284649 AFAICT, char is unsigned on s390. Relying on that is a little subtle. The problem here is that if char happens to be signed and e.g. card->info.mcl_level[2] contains the value -16, the formatted output will be "fffffff0", thus overflowing card->info.mcl_level (which has size 5). To help future readers, simply do an explicit mask so that the value passed to sprintf is in 0-255. If char is indeed unsigned, gcc should be able to elide the masking. In any case, the subsequent 0-termination is redundant, since sprintf has done that. Signed-off-by: Rasmus Villemoes --- drivers/s390/net/qeth_core_main.c | 6 ++---- 1 file changed, 2 insertions(+), 4 deletions(-) diff --git a/drivers/s390/net/qeth_core_main.c b/drivers/s390/net/qeth_core_main.c index 31ac53fa5cee..84bc4b862fbb 100644 --- a/drivers/s390/net/qeth_core_main.c +++ b/drivers/s390/net/qeth_core_main.c @@ -2682,10 +2682,8 @@ void qeth_print_status_message(struct qeth_card *card) * */ if (!card->info.mcl_level[0]) { sprintf(card->info.mcl_level, "%02x%02x", - card->info.mcl_level[2], - card->info.mcl_level[3]); - - card->info.mcl_level[QETH_MCL_LENGTH] = 0; + card->info.mcl_level[2] & 0xff, + card->info.mcl_level[3] & 0xff); break; } /* fallthrough */ -- 2.6.1 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/