From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id B8098CD5BC9 for ; Thu, 28 May 2026 00:32:50 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:Content-Transfer-Encoding: Content-Type:In-Reply-To:From:References:Cc:To:Subject:MIME-Version:Date: Message-ID:Reply-To:Content-ID:Content-Description:Resent-Date:Resent-From: Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=NU+WkG0JMZCGGSqCR8dN7ZBIBOJxhf8qjGX+ma2NsKg=; b=3Tn97hhkUmvJnLU7E+DQtrQoaQ PsWP3jWwXHkRnEQo9ys5R1Gl1epmfCzJLcI0hRp++C2Sj9qlDn3CGu39zyoHVNPF24TNBzQQpcGeM SS/3UNU1ddhlx+PUpnZY7dIoUdTHwB/fr4hsYR8S4FXAwkDDZskcPqSy4a/BMS5srBhZJgUNF43Nn 6Wj73Ev57qcAPgXnGic/pG7NnN+f3bCkGbxMafz0FTAuPBB0hytZ6aBmcYn9Zv2Cs04CDUE/iJlLT WFVS0Ev32D+z+u5bG+AQLI/VprIwTpDBnO6dMbtm9nXLRiALw7wjPLVek2vdzm1pBkH7RN4SXOx56 89N4a5gA==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.99.1 #2 (Red Hat Linux)) id 1wSOfx-00000004rfV-23En; Thu, 28 May 2026 00:32:41 +0000 Received: from out-189.mta1.migadu.com ([95.215.58.189]) by bombadil.infradead.org with esmtps (Exim 4.99.1 #2 (Red Hat Linux)) id 1wSOfu-00000004rea-0gDM for linux-arm-kernel@lists.infradead.org; Thu, 28 May 2026 00:32:39 +0000 Message-ID: <935aaec5-5417-3cde-f944-3c04ffbd3458@linux.dev> DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.dev; s=key1; t=1779928342; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=NU+WkG0JMZCGGSqCR8dN7ZBIBOJxhf8qjGX+ma2NsKg=; b=dyisPlEHNGROmDO3PIu1xSoLKqbJ5ya7lkt4PEAUuiOJahBM0lcV7KL1qiKyDISpRWGvHn PU9aaAfjRJt1t0zYYK+VV8AbVWnhtYyWhAho5LVkMGWMq37hd+4E6BJrMBblf7z4Ug1ArL mdEYdaIAxL+2EOtvyfHtndikc337ELA= Date: Wed, 27 May 2026 20:31:59 -0400 MIME-Version: 1.0 Subject: Re: [PATCH] drm: zynqmp_dp: Fix uninitialized variable in debugfs() Content-Language: en-US To: Dan Carpenter Cc: Laurent Pinchart , Tomi Valkeinen , Maarten Lankhorst , Maxime Ripard , Thomas Zimmermann , David Airlie , Simona Vetter , Michal Simek , dri-devel@lists.freedesktop.org, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, kernel-janitors@vger.kernel.org References: X-Report-Abuse: Please report any abuse attempt to abuse@migadu.com and include these headers. From: Sean Anderson In-Reply-To: Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit X-Migadu-Flow: FLOW_OUT X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.9.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20260527_173238_360731_8B931891 X-CRM114-Status: GOOD ( 15.24 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org On 5/25/26 03:16, Dan Carpenter wrote: > If the *ppos is non-zero then simple_write_to_buffer() will not > initialize the start of the buf[] buffer. It doesn't really make sense > to allow non-zero values for *ppos, so check for that at the start and > return -EINVAL. non-zero ppos seems to be handled properly by simple_write_to_buffer. --Sean > Fixes: 28edaacb821c ("drm: zynqmp_dp: Add debugfs interface for compliance testing") > Signed-off-by: Dan Carpenter > --- > drivers/gpu/drm/xlnx/zynqmp_dp.c | 6 ++++++ > 1 file changed, 6 insertions(+) > > diff --git a/drivers/gpu/drm/xlnx/zynqmp_dp.c b/drivers/gpu/drm/xlnx/zynqmp_dp.c > index 7fb11b0a44f0..847179476041 100644 > --- a/drivers/gpu/drm/xlnx/zynqmp_dp.c > +++ b/drivers/gpu/drm/xlnx/zynqmp_dp.c > @@ -1888,6 +1888,9 @@ static ssize_t zynqmp_dp_pattern_write(struct file *file, > ssize_t ret; > int pattern; > > + if (*ppos != 0) > + return -EINVAL; > + > ret = simple_write_to_buffer(buf, sizeof(buf) - 1, ppos, user_buf, > count); > if (ret < 0) > @@ -2028,6 +2031,9 @@ static ssize_t zynqmp_dp_custom_write(struct file *file, > ssize_t ret; > char buf[sizeof(dp->test.custom)]; > > + if (*ppos != 0) > + return -EINVAL; > + > ret = simple_write_to_buffer(buf, sizeof(buf), ppos, user_buf, count); > if (ret < 0) > return ret;