2023-12-14 16:29:36

by Javier Carrasco

Subject: [PATCH v2 3/4] usb: typec: tipd: declare in_data in as const in exec_cmd functions

The input data passed to execute commands with tps6598x_exec_cmd()
is not supposed to be modified by the function. Moreover, this data is
passed to tps6598x_exec_cmd_tmo() and finally to tps6598x_block_write(),
which expects a const pointer.

The current implementation does not produce any bugs, but it discards
const qualifiers from the pointers passed as arguments. This leads to
compile issues if 'discarded-qualifiers' is active and a const pointer
is passed to the function, which is the case if data from a firmware
structure is passed to execute update commands. Adding the const
modifier to in_data prevents such issues and provides code consistency.

Signed-off-by: Javier Carrasco <[email protected]>
---
drivers/usb/typec/tipd/core.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/usb/typec/tipd/core.c b/drivers/usb/typec/tipd/core.c
index 83e5eeecdf5c..7f4bbc0629b0 100644
--- a/drivers/usb/typec/tipd/core.c
+++ b/drivers/usb/typec/tipd/core.c
@@ -330,7 +330,7 @@ static void tps6598x_disconnect(struct tps6598x *tps, u32 status)
}

static int tps6598x_exec_cmd_tmo(struct tps6598x *tps, const char *cmd,
- size_t in_len, u8 *in_data,
+ size_t in_len, const u8 *in_data,
size_t out_len, u8 *out_data,
u32 cmd_timeout_ms, u32 res_delay_ms)
{
@@ -396,7 +396,7 @@ static int tps6598x_exec_cmd_tmo(struct tps6598x *tps, const char *cmd,
}

static int tps6598x_exec_cmd(struct tps6598x *tps, const char *cmd,
- size_t in_len, u8 *in_data,
+ size_t in_len, const u8 *in_data,
size_t out_len, u8 *out_data)
{
return tps6598x_exec_cmd_tmo(tps, cmd, in_len, in_data,

--
2.39.2

2023-12-19 11:52:13

by Heikki Krogerus

Subject: Re: [PATCH v2 3/4] usb: typec: tipd: declare in_data in as const in exec_cmd functions

On Thu, Dec 14, 2023 at 05:29:11PM +0100, Javier Carrasco wrote:
> The input data passed to execute commands with tps6598x_exec_cmd()
> is not supposed to be modified by the function. Moreover, this data is
> passed to tps6598x_exec_cmd_tmo() and finally to tps6598x_block_write(),
> which expects a const pointer.
>
> The current implementation does not produce any bugs, but it discards
> const qualifiers from the pointers passed as arguments. This leads to
> compile issues if 'discarded-qualifiers' is active and a const pointer
> is passed to the function, which is the case if data from a firmware
> structure is passed to execute update commands. Adding the const
> modifier to in_data prevents such issues and provides code consistency.
>
> Signed-off-by: Javier Carrasco <[email protected]>

Reviewed-by: Heikki Krogerus <[email protected]>

> ---
> drivers/usb/typec/tipd/core.c | 4 ++--
> 1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/usb/typec/tipd/core.c b/drivers/usb/typec/tipd/core.c
> index 83e5eeecdf5c..7f4bbc0629b0 100644
> --- a/drivers/usb/typec/tipd/core.c
> +++ b/drivers/usb/typec/tipd/core.c
> @@ -330,7 +330,7 @@ static void tps6598x_disconnect(struct tps6598x *tps, u32 status)
> }
>
> static int tps6598x_exec_cmd_tmo(struct tps6598x *tps, const char *cmd,
> - size_t in_len, u8 *in_data,
> + size_t in_len, const u8 *in_data,
> size_t out_len, u8 *out_data,
> u32 cmd_timeout_ms, u32 res_delay_ms)
> {
> @@ -396,7 +396,7 @@ static int tps6598x_exec_cmd_tmo(struct tps6598x *tps, const char *cmd,
> }
>
> static int tps6598x_exec_cmd(struct tps6598x *tps, const char *cmd,
> - size_t in_len, u8 *in_data,
> + size_t in_len, const u8 *in_data,
> size_t out_len, u8 *out_data)
> {
> return tps6598x_exec_cmd_tmo(tps, cmd, in_len, in_data,
>
> --
> 2.39.2

--
heikki