From: Dan Carpenter <dan.carpenter@linaro.org>
To: Sai Krishna <saikrishnag@marvell.com>
Cc: davem@davemloft.net, edumazet@google.com, kuba@kernel.org,
pabeni@redhat.com, netdev@vger.kernel.org,
linux-kernel@vger.kernel.org, sgoutham@marvell.com,
maciej.fijalkowski@intel.com,
Naveen Mamindlapalli <naveenm@marvell.com>
Subject: Re: [net PATCH v2] octeontx2-af: Move validation of ptp pointer before its usage
Date: Fri, 9 Jun 2023 16:18:08 +0300 [thread overview]
Message-ID: <880d628e-18bf-44a1-a55f-ffbe1777dd2b@kadam.mountain> (raw)
In-Reply-To: <20230609115806.2625564-1-saikrishnag@marvell.com>
On Fri, Jun 09, 2023 at 05:28:06PM +0530, Sai Krishna wrote:
> @@ -428,7 +427,7 @@ static int ptp_probe(struct pci_dev *pdev,
> return 0;
>
> error_free:
> - devm_kfree(dev, ptp);
> + kfree(ptp);
Yeah. It's strange any time we call devm_kfree()... So there is
something here which I have not understood.
>
> error:
> /* For `ptp_get()` we need to differentiate between the case
This probe function is super weird how it returns success on the failure
path. One concern, I had initially was that if anything returns
-EPROBE_DEFER then we cannot recover. That's not possible in the
current code, but it makes me itch... But here is a different crash.
drivers/net/ethernet/marvell/octeontx2/af/ptp.c
432 error:
433 /* For `ptp_get()` we need to differentiate between the case
434 * when the core has not tried to probe this device and the case when
435 * the probe failed. In the later case we pretend that the
436 * initialization was successful and keep the error in
437 * `dev->driver_data`.
438 */
439 pci_set_drvdata(pdev, ERR_PTR(err));
440 if (!first_ptp_block)
441 first_ptp_block = ERR_PTR(err);
first_ptp_block is NULL for unprobed, an error pointer for probe
failure, or valid pointer.
442
443 return 0;
444 }
drivers/net/ethernet/marvell/octeontx2/af/ptp.c
201 struct ptp *ptp_get(void)
202 {
203 struct ptp *ptp = first_ptp_block;
^^^^^^^^^^^^^^^^^^^^^^
204
205 /* Check PTP block is present in hardware */
206 if (!pci_dev_present(ptp_id_table))
207 return ERR_PTR(-ENODEV);
208 /* Check driver is bound to PTP block */
209 if (!ptp)
210 ptp = ERR_PTR(-EPROBE_DEFER);
211 else
212 pci_dev_get(ptp->pdev);
^^^^^^^^^
if first_ptp_block is an error pointer this will Oops.
213
214 return ptp;
215 }
regards,
dan carpenter
next prev parent reply other threads:[~2023-06-09 13:18 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-06-09 11:58 [net PATCH v2] octeontx2-af: Move validation of ptp pointer before its usage Sai Krishna
2023-06-09 13:18 ` Dan Carpenter [this message]
2023-06-23 11:28 ` Sai Krishna Gajula
2023-06-23 11:44 ` Dan Carpenter
2023-06-30 5:19 ` Sai Krishna Gajula
2023-06-30 5:45 ` Dan Carpenter
2023-06-30 6:46 ` Sunil Kovvuri
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