From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mgamail.intel.com (mgamail.intel.com [198.175.65.15]) (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 EAACF8834 for ; Tue, 23 Sep 2025 13:51:47 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=198.175.65.15 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1758635510; cv=none; b=ktUErmDfiLwfv0rfMJ/xKH74z6RSQCEom/6ZThJD+up751UrQnu+h9i2S1iJvDr9uuhH6IPpyZfOb9/vsVI1Re1ZgvrGkazkmd6dteDe0GSf038q7JnTgJzafSmBPOg/B6fwHx/XuCA5pZCRyzZrY1+RXxxtnPpznufRJDTBaCE= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1758635510; c=relaxed/simple; bh=KNsHfCNP5BcDpTQ3p9SIHGa9nh0HGDtnumDcWKGG+V0=; h=From:To:Cc:Subject:In-Reply-To:References:Date:Message-ID: MIME-Version:Content-Type; b=Xhh7plPmGzFFNUj0kFr19eSMecWcGH9mmiOQ/g5Q5fLomexeOEPElgU2GeEZ1LnlgDIUFjMpGvamd9vniBJXk16DI8FpFsbwa6OPGXNo7xu9JWLstvb22vlGVDOgAHfeqfSHAUn/K/DGeWXJY+LQYHVCVUISp6SrP4298p8QUaE= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.intel.com; spf=pass smtp.mailfrom=intel.com; dkim=pass (2048-bit key) header.d=intel.com header.i=@intel.com header.b=RAX4jeqN; arc=none smtp.client-ip=198.175.65.15 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.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="RAX4jeqN" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1758635508; x=1790171508; h=from:to:cc:subject:in-reply-to:references:date: message-id:mime-version; bh=KNsHfCNP5BcDpTQ3p9SIHGa9nh0HGDtnumDcWKGG+V0=; b=RAX4jeqNntM/TQJNLrnfQhBVknl2M8vRfd8xNKP/KVQZFD05LHFUC41Q weIryhpGfJj3C8zbTLQx3N+LulO/747kGUejHeLysNroAcReI+DyquPGb 7sPBye9mXhFTuBtdSyCDh3XsOFLFSwJezXHzGhiO80HOi7X/9UizrfUFn Lzln4bX7M9ZkB43TE96cAPbS15wKlRatmrXf3LO/nCf4id2Iu7XyN2ZXm f073L//Zo5xm+o8G4/uUx9aqreXZ+uI3ROywXyIMZALXuavczn6722yi6 /pKPkmmRqCBpe44G/CIj7XtSPA0JecoOnrl/XGrDZV2lNEMXME954WP6t A==; X-CSE-ConnectionGUID: gyziRBxkTY6Bi0E5k6VaLA== X-CSE-MsgGUID: 9jqPRAzSQi2oxvQH2XAgbA== X-IronPort-AV: E=McAfee;i="6800,10657,11561"; a="64550598" X-IronPort-AV: E=Sophos;i="6.18,288,1751266800"; d="scan'208";a="64550598" Received: from orviesa005.jf.intel.com ([10.64.159.145]) by orvoesa107.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 23 Sep 2025 06:51:47 -0700 X-CSE-ConnectionGUID: NPFOkG42QwKwZ+wCXwUQmg== X-CSE-MsgGUID: ae/oMbIkS7me6pQQdxZZ3g== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="6.18,288,1751266800"; d="scan'208";a="181940449" Received: from mwiniars-desk2.ger.corp.intel.com (HELO localhost) ([10.245.246.94]) by orviesa005-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 23 Sep 2025 06:51:43 -0700 From: Jani Nikula To: Rahul Kumar , lanzano.alex@gmail.com, maarten.lankhorst@linux.intel.com, mripard@kernel.org, tzimmermann@suse.de, airlied@gmail.com, simona@ffwll.ch Cc: dri-devel@lists.freedesktop.org, linux-kernel@vger.kernel.org, linux-kernel-mentees@lists.linuxfoundation.org, skhan@linuxfoundation.org, rk0006818@gmail.com Subject: Re: [PATCH] drm/tiny: Use kmalloc_array() instead of kmalloc() In-Reply-To: <20250923110025.1358920-1-rk0006818@gmail.com> Organization: Intel Finland Oy - BIC 0357606-4 - Westendinkatu 7, 02160 Espoo References: <20250923110025.1358920-1-rk0006818@gmail.com> Date: Tue, 23 Sep 2025 16:51:40 +0300 Message-ID: <712a27fc6c4060e67b3da58cb8564387b40b5971@intel.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain On Tue, 23 Sep 2025, Rahul Kumar wrote: > Documentation/process/deprecated.rst recommends against the use of > kmalloc with dynamic size calculations due to the risk of overflow and > smaller allocation being made than the caller was expecting. > > Replace kmalloc() with kmalloc_array() in drivers/gpu/drm/tiny/repaper.c > to make the intended allocation size clearer and avoid potential overflow > issues. > > Signed-off-by: Rahul Kumar > --- > drivers/gpu/drm/tiny/repaper.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/drivers/gpu/drm/tiny/repaper.c b/drivers/gpu/drm/tiny/repaper.c > index 5c3b51eb0a97..4d439a2d973a 100644 > --- a/drivers/gpu/drm/tiny/repaper.c > +++ b/drivers/gpu/drm/tiny/repaper.c > @@ -535,7 +535,7 @@ static int repaper_fb_dirty(struct drm_framebuffer *fb, > DRM_DEBUG("Flushing [FB:%d] st=%ums\n", fb->base.id, > epd->factored_stage_time); > > - buf = kmalloc(fb->width * fb->height / 8, GFP_KERNEL); > + buf = kmalloc_array(fb->width, fb->height / 8, GFP_KERNEL); That's just not the same thing, though. BR, Jani. > if (!buf) { > ret = -ENOMEM; > goto out_exit; -- Jani Nikula, Intel