From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 1FEBD171A5 for ; Fri, 17 Nov 2023 09:52:01 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="VI4q2I7E" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 15245C433C7; Fri, 17 Nov 2023 09:51:59 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1700214721; bh=5HsDJUIpq+WzQyoTIrlE2LCZwPI5r2SD0ENhnQYLf1c=; h=Date:Subject:To:Cc:References:From:In-Reply-To:From; b=VI4q2I7EkqkFG6srWleLxAYUsWZgEVJLttuy3A0pOI2L1sYGJhbWk0hxY+apO057T dcm56loYfQEy+G4pa12a4kv/3IuXnCEV/YXXAcNBoG+xScoJduED0hv1jd9s7XESmo KvB9Uj28b6caL4UP7lPC2JuHnueRBLTlwJUuZZ8W7RvA0R0RIJW9l3/oaxDA9TYPVZ 7JkRJVhwKkxehp5h7QaPet4RrIwFjFpTVmQHOOtG4vRCwMqCtA0eMO3DsYNqbHHhX9 Q/tm78NUfm/hWEx4yX3ENGXr7XFIFD88yNnm3w8DOMcLk9Blzmz9fWAaBHHfrNNYt9 I9Q4s6ct/jBAg== Message-ID: Date: Fri, 17 Nov 2023 11:51:56 +0200 Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH 1/7] net: ethernet: ti: am65-cpsw: Don't error out in .remove() Content-Language: en-US To: =?UTF-8?Q?Uwe_Kleine-K=C3=B6nig?= Cc: Siddharth Vadapalli , Dan Carpenter , netdev@vger.kernel.org, kernel@pengutronix.de References: <20231117091655.872426-1-u.kleine-koenig@pengutronix.de> <20231117091655.872426-2-u.kleine-koenig@pengutronix.de> From: Roger Quadros In-Reply-To: <20231117091655.872426-2-u.kleine-koenig@pengutronix.de> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit On 17/11/2023 11:16, Uwe Kleine-König wrote: > Returning early from .remove() with an error code still results in the > driver unbinding the device. So the driver core ignores the returned error > code and the resources that were not freed are never catched up. In > combination with devm this also often results in use-after-free bugs. > > In case of the am65-cpsw-nuss driver there is an error path, but it's never > taken because am65_cpts_resume() never fails (which however might be > another problem). Still make this explicit and drop the early return in > exchange for an error message (that is more useful than the error the > driver core emits when .remove() returns non-zero). > > This prepares changing am65_cpsw_nuss_remove() to return void. > > Fixes: 93a76530316a ("net: ethernet: ti: introduce am65x/j721e gigabit eth subsystem driver") > Signed-off-by: Uwe Kleine-König > --- > drivers/net/ethernet/ti/am65-cpsw-nuss.c | 7 +++++-- > 1 file changed, 5 insertions(+), 2 deletions(-) > > diff --git a/drivers/net/ethernet/ti/am65-cpsw-nuss.c b/drivers/net/ethernet/ti/am65-cpsw-nuss.c > index ece9f8df98ae..960cb3fa0754 100644 > --- a/drivers/net/ethernet/ti/am65-cpsw-nuss.c > +++ b/drivers/net/ethernet/ti/am65-cpsw-nuss.c > @@ -3007,9 +3007,12 @@ static int am65_cpsw_nuss_remove(struct platform_device *pdev) > > common = dev_get_drvdata(dev); > > - ret = pm_runtime_resume_and_get(&pdev->dev); > + ret = pm_runtime_get_sync(&pdev->dev); Unrelated to this patch but I see pm_runtime_resume_and_get() used at multiple places in this driver. Would it be wise to replace them all with pm_runtime_get_sync()? > if (ret < 0) > - return ret; > + /* am65_cpts_resume() doesn't fail, so handling ret < 0 is only > + * for the sake of completeness. > + */ > + dev_err(dev, "runtime resume failed (%pe)\n", ERR_PTR(ret)); > > am65_cpsw_unregister_devlink(common); > am65_cpsw_unregister_notifiers(common); -- cheers, -roger