From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from perceval.ideasonboard.com (perceval.ideasonboard.com [213.167.242.64]) (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 4B78124886A; Mon, 22 Jun 2026 11:55:48 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=213.167.242.64 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1782129350; cv=none; b=ScPE40RWX65jl3lMwdjW3tVIIq08mSlwGULUFKsYfH/6hNoZXnFO/bEXbvC4w/2Q7ipdMHXJyZWw7Ioft494MwBN/nDDwsqKpybBWLgytjypavXaYeEkq6SBtzfT/rIXWGqDLk3c9QXiMBpKGji48SfFT3VC3WHFnASjBluurvg= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1782129350; c=relaxed/simple; bh=TDWFD3aVcqsYOWPdtLK1KFJLiTGZTVKDYeLf7bJYrTI=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=dE3bMDLInphmx8ZOGARJlcTjzchFZjMLKgwHmRvCXZ589yREMVTJXt3i4PJuW6E2MTJV5UbTseyXFeMy/Z9ciM+WDCOgxLX7HjP1roQgWocHi/4alVo5tji/MCeGAUQs5DC4xV4MKcezODR7DtH9NIa6gyB9LaEJAthxQSABITM= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=ideasonboard.com; spf=pass smtp.mailfrom=ideasonboard.com; dkim=pass (1024-bit key) header.d=ideasonboard.com header.i=@ideasonboard.com header.b=gXqVCwUZ; arc=none smtp.client-ip=213.167.242.64 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=ideasonboard.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=ideasonboard.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=ideasonboard.com header.i=@ideasonboard.com header.b="gXqVCwUZ" Received: from killaraus.ideasonboard.com (2001-14ba-70f3-e800--a06.rev.dnainternet.fi [IPv6:2001:14ba:70f3:e800::a06]) by perceval.ideasonboard.com (Postfix) with ESMTPSA id 3A7F29CE; Mon, 22 Jun 2026 13:55:08 +0200 (CEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=ideasonboard.com; s=mail; t=1782129308; bh=TDWFD3aVcqsYOWPdtLK1KFJLiTGZTVKDYeLf7bJYrTI=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=gXqVCwUZLPEnE7+3WkZgPXN8wj92R1iMQN4M2WulFhoKn0NvAfnk3KZEWuZgsup5D 8RoaWA0hX6YTShku4A/WXvC7oWXoVYz8aYCGcrzpDgRyQdiF9DSQq8L4frK/138L3R 7KtnEvqzi26otYw6b7lxtx7g1yobSEfXkbX8oo5A= Date: Mon, 22 Jun 2026 14:55:44 +0300 From: Laurent Pinchart To: Biren Pandya Cc: maarten.lankhorst@linux.intel.com, mripard@kernel.org, tzimmermann@suse.de, airlied@gmail.com, simona@ffwll.ch, sumit.semwal@linaro.org, christian.koenig@amd.com, dri-devel@lists.freedesktop.org, linux-kernel@vger.kernel.org, linux-media@vger.kernel.org, linaro-mm-sig@lists.linaro.org Subject: Re: [PATCH] drm/gem: modernize locks to use scoped_guard() Message-ID: <20260622115544.GA3899302@killaraus.ideasonboard.com> References: <20260616181956.61476-2-birenpandya@gmail.com> Precedence: bulk X-Mailing-List: linux-media@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <20260616181956.61476-2-birenpandya@gmail.com> On Tue, Jun 16, 2026 at 11:49:57PM +0530, Biren Pandya wrote: > Several GEM core functions manually managed mutex_lock() and > mutex_unlock() over single scopes or error paths. This adds boilerplate > and carries the risk of lock leaks if error paths are refactored. > > Modernize these locks by deploying the scoped_guard() > macro. This ensures that the locks are reliably dropped when the block > exits, cleanly removing goto out_unlock paths and tightening the > lifecycle. What's the reason for doing so in in drm_gem and not other areas in DRM ? > Signed-off-by: Biren Pandya > > Compiled locally, but requires IGT validation by the DRM CI. > --- > drivers/gpu/drm/drm_gem.c | 66 ++++++++++++++++++--------------------- > 1 file changed, 30 insertions(+), 36 deletions(-) > > diff --git a/drivers/gpu/drm/drm_gem.c b/drivers/gpu/drm/drm_gem.c > index 891c3bff5ae0..d3a061d42ba7 100644 > --- a/drivers/gpu/drm/drm_gem.c > +++ b/drivers/gpu/drm/drm_gem.c > @@ -346,13 +346,13 @@ void drm_gem_object_handle_put_unlocked(struct drm_gem_object *obj) > * we checked for a name. > */ > > - mutex_lock(&dev->object_name_lock); > - if (--obj->handle_count == 0) { > - drm_gem_object_handle_free(obj); > - drm_gem_object_exported_dma_buf_free(obj); > - final = true; > + scoped_guard(mutex, &dev->object_name_lock) { > + if (--obj->handle_count == 0) { > + drm_gem_object_handle_free(obj); > + drm_gem_object_exported_dma_buf_free(obj); > + final = true; > + } > } > - mutex_unlock(&dev->object_name_lock); > > if (final) > drm_gem_object_put(obj); > @@ -374,11 +374,8 @@ drm_gem_object_release_handle(int id, void *ptr, void *data) > if (obj->funcs->close) > obj->funcs->close(obj, file_priv); > > - mutex_lock(&file_priv->prime.lock); > - > - drm_prime_remove_buf_handle(&file_priv->prime, id); > - > - mutex_unlock(&file_priv->prime.lock); > + scoped_guard(mutex, &file_priv->prime.lock) > + drm_prime_remove_buf_handle(&file_priv->prime, id); > > drm_vma_node_revoke(&obj->vma_node, file_priv); > > @@ -1021,37 +1018,34 @@ int drm_gem_change_handle_ioctl(struct drm_device *dev, void *data, > goto out; > } > > - mutex_lock(&file_priv->prime.lock); > + scoped_guard(mutex, &file_priv->prime.lock) { > + spin_lock(&file_priv->table_lock); > + ret = idr_alloc(&file_priv->object_idr, obj, handle, handle + 1, > + GFP_NOWAIT); > + spin_unlock(&file_priv->table_lock); And why don't you use guards for the spinlock as well ? > > - spin_lock(&file_priv->table_lock); > - ret = idr_alloc(&file_priv->object_idr, obj, handle, handle + 1, > - GFP_NOWAIT); > - spin_unlock(&file_priv->table_lock); > + if (ret < 0) > + break; > > - if (ret < 0) > - goto out_unlock; > + if (obj->dma_buf) { > + ret = drm_prime_add_buf_handle(&file_priv->prime, obj->dma_buf, > + handle); > + if (ret < 0) { > + spin_lock(&file_priv->table_lock); > + idr_remove(&file_priv->object_idr, handle); > + spin_unlock(&file_priv->table_lock); > + break; > + } > > - if (obj->dma_buf) { > - ret = drm_prime_add_buf_handle(&file_priv->prime, obj->dma_buf, > - handle); > - if (ret < 0) { > - spin_lock(&file_priv->table_lock); > - idr_remove(&file_priv->object_idr, handle); > - spin_unlock(&file_priv->table_lock); > - goto out_unlock; > + drm_prime_remove_buf_handle(&file_priv->prime, args->handle); > } > > - drm_prime_remove_buf_handle(&file_priv->prime, args->handle); > - } > - > - ret = 0; > - > - spin_lock(&file_priv->table_lock); > - idr_remove(&file_priv->object_idr, args->handle); > - spin_unlock(&file_priv->table_lock); > + ret = 0; > > -out_unlock: > - mutex_unlock(&file_priv->prime.lock); > + spin_lock(&file_priv->table_lock); > + idr_remove(&file_priv->object_idr, args->handle); > + spin_unlock(&file_priv->table_lock); > + } > out: > drm_gem_object_put(obj); > > > base-commit: 72c25183cac9bc584c9de21797a5883af44bcc7a -- Regards, Laurent Pinchart