From: Chanwoo Choi <chanwoo@kernel.org>
To: Stanley Chang <stanley_chang@realtek.com>,
Chanwoo Choi <cw00.choi@samsung.com>
Cc: Dan Carpenter <dan.carpenter@linaro.org>,
MyungJoo Ham <myungjoo.ham@samsung.com>,
linux-kernel@vger.kernel.org
Subject: Re: [PATCH extcon-next] extcon: realtek: add the error handler for nvmem_cell_read
Date: Tue, 17 Oct 2023 17:41:22 +0900 [thread overview]
Message-ID: <c2b7a88c-2a6d-49f6-974a-5f21915aea3c@kernel.org> (raw)
In-Reply-To: <20231016053510.28881-1-stanley_chang@realtek.com>
On 23. 10. 16. 14:35, Stanley Chang wrote:
> There are following smatch warning:
> drivers/extcon/extcon-rtk-type-c.c:905 __updated_type_c_parameter_by_efuse()
> error: 'buf' dereferencing possible ERR_PTR()
>
> The nvmem_cell_read may fail to read. So, driver must handle failure cases.
>
> Fixes: 8a590d7371f0 ("extcon: add Realtek DHC RTD SoC Type-C driver")
> Reported-by: Dan Carpenter <dan.carpenter@linaro.org>
> Closes: https://lore.kernel.org/all/a469dd51-f5d5-4e8f-ba36-6c7cea046fb8@moroto.mountain/
> Signed-off-by: Stanley Chang <stanley_chang@realtek.com>
> ---
> drivers/extcon/extcon-rtk-type-c.c | 86 +++++++++++++++---------------
> 1 file changed, 44 insertions(+), 42 deletions(-)
>
> diff --git a/drivers/extcon/extcon-rtk-type-c.c b/drivers/extcon/extcon-rtk-type-c.c
> index 00465cfba23e..a592bab77538 100644
> --- a/drivers/extcon/extcon-rtk-type-c.c
> +++ b/drivers/extcon/extcon-rtk-type-c.c
> @@ -901,25 +901,26 @@ static int __updated_type_c_parameter_by_efuse(struct type_c_data *type_c)
> int value_mask = (BIT(value_size) - 1);
>
> buf = nvmem_cell_read(cell, &buf_size);
> -
> - cc1_0p2v = get_value((buf[0] >> value_size * 0) & value_mask);
> - cc1_0p8v = get_value((buf[0] >> value_size * 1) & value_mask);
> - cc1_2p6v = get_value((buf[1] >> value_size * 0) & value_mask);
> - cc1_0p66v = get_value((buf[1] >> value_size * 1) & value_mask);
> - cc1_1p23v = get_value((buf[2] >> value_size * 0) & value_mask);
> -
> - cc2_0p2v = get_value((buf[3] >> value_size * 0) & value_mask);
> - cc2_0p8v = get_value((buf[3] >> value_size * 1) & value_mask);
> - cc2_2p6v = get_value((buf[4] >> value_size * 0) & value_mask);
> - cc2_0p66v = get_value((buf[4] >> value_size * 1) & value_mask);
> - cc2_1p23v = get_value((buf[5] >> value_size * 0) & value_mask);
> -
> - cc1_4p7k = get_value((buf[6] >> value_size * 0) & value_mask);
> - cc1_12k = get_value((buf[6] >> value_size * 1) & value_mask);
> - cc2_4p7k = get_value((buf[7] >> value_size * 0) & value_mask);
> - cc2_12k = get_value((buf[7] >> value_size * 1) & value_mask);
> -
> - kfree(buf);
> + if (!IS_ERR(buf)) {
> + cc1_0p2v = get_value((buf[0] >> value_size * 0) & value_mask);
> + cc1_0p8v = get_value((buf[0] >> value_size * 1) & value_mask);
> + cc1_2p6v = get_value((buf[1] >> value_size * 0) & value_mask);
> + cc1_0p66v = get_value((buf[1] >> value_size * 1) & value_mask);
> + cc1_1p23v = get_value((buf[2] >> value_size * 0) & value_mask);
> +
> + cc2_0p2v = get_value((buf[3] >> value_size * 0) & value_mask);
> + cc2_0p8v = get_value((buf[3] >> value_size * 1) & value_mask);
> + cc2_2p6v = get_value((buf[4] >> value_size * 0) & value_mask);
> + cc2_0p66v = get_value((buf[4] >> value_size * 1) & value_mask);
> + cc2_1p23v = get_value((buf[5] >> value_size * 0) & value_mask);
> +
> + cc1_4p7k = get_value((buf[6] >> value_size * 0) & value_mask);
> + cc1_12k = get_value((buf[6] >> value_size * 1) & value_mask);
> + cc2_4p7k = get_value((buf[7] >> value_size * 0) & value_mask);
> + cc2_12k = get_value((buf[7] >> value_size * 1) & value_mask);
> +
> + kfree(buf);
> + }
> nvmem_cell_put(cell);
> }
>
> @@ -984,29 +985,30 @@ static int __updated_type_c_parameter_by_efuse_v2(struct type_c_data *type_c)
> int value_mask = (BIT(value_size) - 1);
>
> buf = nvmem_cell_read(cell, &buf_size);
> -
> - value_size = 5;
> - value_mask = (BIT(value_size) - 1);
> - cc1_4p7k = buf[0] & value_mask;
> - cc1_12k = buf[1] & value_mask;
> - cc2_4p7k = buf[2] & value_mask;
> - cc2_12k = buf[3] & value_mask;
> -
> - value_size = 4;
> - value_mask = (BIT(value_size) - 1);
> - cc1_0p2v = (buf[4] >> value_size * 0) & value_mask;
> - cc1_0p66v = (buf[4] >> value_size * 1) & value_mask;
> - cc1_0p8v = (buf[5] >> value_size * 0) & value_mask;
> - cc1_1p23v = (buf[5] >> value_size * 1) & value_mask;
> - cc1_2p6v = (buf[6] >> value_size * 0) & value_mask;
> -
> - cc2_0p2v = (buf[6] >> value_size * 1) & value_mask;
> - cc2_0p66v = (buf[7] >> value_size * 0) & value_mask;
> - cc2_0p8v = (buf[7] >> value_size * 1) & value_mask;
> - cc2_1p23v = (buf[8] >> value_size * 0) & value_mask;
> - cc2_2p6v = (buf[8] >> value_size * 1) & value_mask;
> -
> - kfree(buf);
> + if (!IS_ERR(buf)) {
> + value_size = 5;
> + value_mask = (BIT(value_size) - 1);
> + cc1_4p7k = buf[0] & value_mask;
> + cc1_12k = buf[1] & value_mask;
> + cc2_4p7k = buf[2] & value_mask;
> + cc2_12k = buf[3] & value_mask;
> +
> + value_size = 4;
> + value_mask = (BIT(value_size) - 1);
> + cc1_0p2v = (buf[4] >> value_size * 0) & value_mask;
> + cc1_0p66v = (buf[4] >> value_size * 1) & value_mask;
> + cc1_0p8v = (buf[5] >> value_size * 0) & value_mask;
> + cc1_1p23v = (buf[5] >> value_size * 1) & value_mask;
> + cc1_2p6v = (buf[6] >> value_size * 0) & value_mask;
> +
> + cc2_0p2v = (buf[6] >> value_size * 1) & value_mask;
> + cc2_0p66v = (buf[7] >> value_size * 0) & value_mask;
> + cc2_0p8v = (buf[7] >> value_size * 1) & value_mask;
> + cc2_1p23v = (buf[8] >> value_size * 0) & value_mask;
> + cc2_2p6v = (buf[8] >> value_size * 1) & value_mask;
> +
> + kfree(buf);
> + }
> nvmem_cell_put(cell);
> }
>
Applied it. Thanks.
--
Best Regards,
Samsung Electronics
Chanwoo Choi
next prev parent reply other threads:[~2023-10-17 8:41 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-10-16 5:35 Stanley Chang
2023-10-17 8:41 ` Chanwoo Choi [this message]
2023-10-18 3:14 ` Stanley Chang[昌育德]
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=c2b7a88c-2a6d-49f6-974a-5f21915aea3c@kernel.org \
--to=chanwoo@kernel.org \
--cc=cw00.choi@samsung.com \
--cc=dan.carpenter@linaro.org \
--cc=linux-kernel@vger.kernel.org \
--cc=myungjoo.ham@samsung.com \
--cc=stanley_chang@realtek.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox
all inboxes | Powered by JetHome®