On 5/20/22 20:21, Uwe Kleine-König wrote:
> EXTERNAL EMAIL: Do not click links or open attachments unless you know the content is safe
>
> Returning an error value in an i2c remove callback results in an error
> message being emitted by the i2c core, but otherwise it doesn't make a
> difference. The device goes away anyhow and the devm cleanups are
> called.
>
> As atmel_ecc_remove() already emits an error message on failure and the
> additional error message by the i2c core doesn't add any useful
> information, change the return value to zero to suppress this message.
>
> Also make the error message a bit more drastical because when the device
> is still busy on remove, it's likely that it will access freed memory
> soon.
>
> This patch is a preparation for making i2c remove callbacks return void.
>
> Signed-off-by: Uwe Kleine-König <u.kleine-koenig@xxxxxxxxxxxxxx>
Reviewed-by: Tudor Ambarus <tudor.ambarus@xxxxxxxxxxxxx>
> ---
> drivers/crypto/atmel-ecc.c | 12 ++++++++++--
> 1 file changed, 10 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/crypto/atmel-ecc.c b/drivers/crypto/atmel-ecc.c
> index 333fbefbbccb..6ba38275de8c 100644
> --- a/drivers/crypto/atmel-ecc.c
> +++ b/drivers/crypto/atmel-ecc.c
> @@ -349,8 +349,16 @@ static int atmel_ecc_remove(struct i2c_client *client)
>
> /* Return EBUSY if i2c client already allocated. */
> if (atomic_read(&i2c_priv->tfm_count)) {
> - dev_err(&client->dev, "Device is busy\n");
> - return -EBUSY;
> + /*
> + * After we return here, the memory backing the device is freed.
> + * That happens no matter what the return value of this function
> + * is because in the Linux device model there is no error
> + * handling for unbinding a driver.
> + * If there is still some action pending, it probably involves
> + * accessing the freed memory.
> + */
> + dev_emerg(&client->dev, "Device is busy, expect memory corruption.\n");
> + return 0;
> }
>
> crypto_unregister_kpp(&atmel_ecdh_nist_p256);
>
> base-commit: 3123109284176b1532874591f7c81f3837bbdc17
> --
> 2.35.1
>
