2022-12-26 10:57:41

by Yang Yang

[permalink] [raw]

Subject: [PATCH linux-next v2] parisc: use strscpy() to instead of strncpy()

---

From: Xu Panda <[email protected]>

The implementation of strscpy() is more robust and safer.
That's now the recommended way to copy NUL-terminated strings.

Signed-off-by: Xu Panda <[email protected]>
Signed-off-by: Yang Yang <[email protected]>
---
change for v2
- sizeof(in) is better and simplified, thanks for Helge Deller.
---
drivers/parisc/pdc_stable.c | 9 +++------
1 file changed, 3 insertions(+), 6 deletions(-)

diff --git a/drivers/parisc/pdc_stable.c b/drivers/parisc/pdc_stable.c
index d6af5726ddf3..d3075445260b 100644
--- a/drivers/parisc/pdc_stable.c
+++ b/drivers/parisc/pdc_stable.c
@@ -274,8 +274,7 @@ pdcspath_hwpath_write(struct pdcspath_entry *entry, const char *buf, size_t coun

/* We'll use a local copy of buf */
count = min_t(size_t, count, sizeof(in)-1);
- strncpy(in, buf, count);
- in[count] = '\0';
+ strscpy(in, buf, sizeof(in));

/* Let's clean up the target. 0xff is a blank pattern */
memset(&hwpath, 0xff, sizeof(hwpath));
@@ -388,8 +387,7 @@ pdcspath_layer_write(struct pdcspath_entry *entry, const char *buf, size_t count

/* We'll use a local copy of buf */
count = min_t(size_t, count, sizeof(in)-1);
- strncpy(in, buf, count);
- in[count] = '\0';
+ strscpy(in, buf, sizeof(in));

/* Let's clean up the target. 0 is a blank pattern */
memset(&layers, 0, sizeof(layers));
@@ -756,8 +754,7 @@ static ssize_t pdcs_auto_write(struct kobject *kobj,

/* We'll use a local copy of buf */
count = min_t(size_t, count, sizeof(in)-1);
- strncpy(in, buf, count);
- in[count] = '\0';
+ strscpy(in, buf, sizeof(in));

/* Current flags are stored in primary boot path entry */
pathentry = &pdcspath_entry_primary;
--
2.15.2

2022-12-27 08:13:07

by Rolf Eike Beer

[permalink] [raw]

Subject: Re: [PATCH linux-next v2] parisc: use strscpy() to instead of strncpy()

---

Am Montag, 26. Dezember 2022, 11:40:04 CET schrieb [email protected]:
> From: Xu Panda <[email protected]>
>
> The implementation of strscpy() is more robust and safer.
> That's now the recommended way to copy NUL-terminated strings.
>
> Signed-off-by: Xu Panda <[email protected]>
> Signed-off-by: Yang Yang <[email protected]>
> ---
> change for v2
> - sizeof(in) is better and simplified, thanks for Helge Deller.
> ---
> drivers/parisc/pdc_stable.c | 9 +++------
> 1 file changed, 3 insertions(+), 6 deletions(-)
>
> diff --git a/drivers/parisc/pdc_stable.c b/drivers/parisc/pdc_stable.c
> index d6af5726ddf3..d3075445260b 100644
> --- a/drivers/parisc/pdc_stable.c
> +++ b/drivers/parisc/pdc_stable.c
> @@ -274,8 +274,7 @@ pdcspath_hwpath_write(struct pdcspath_entry *entry,
> const char *buf, size_t coun
>
> /* We'll use a local copy of buf */
> count = min_t(size_t, count, sizeof(in)-1);
> - strncpy(in, buf, count);
> - in[count] = '\0';
> + strscpy(in, buf, sizeof(in));

What is "count" now needed for? Looks like a write only variable at least in
these hunks.

Eike

---

Attachments:

signature.asc (201.00 B)
This is a digitally signed message part.

2022-12-27 22:33:25

by Helge Deller

[permalink] [raw]

Subject: Re: [PATCH linux-next v2] parisc: use strscpy() to instead of strncpy()

---

On 12/27/22 08:47, Rolf Eike Beer wrote:
> Am Montag, 26. Dezember 2022, 11:40:04 CET schrieb [email protected]:
>> From: Xu Panda <[email protected]>
>>
>> The implementation of strscpy() is more robust and safer.
>> That's now the recommended way to copy NUL-terminated strings.
>>
>> Signed-off-by: Xu Panda <[email protected]>
>> Signed-off-by: Yang Yang <[email protected]>
>> ---
>> change for v2
>> - sizeof(in) is better and simplified, thanks for Helge Deller.
>> ---
>> drivers/parisc/pdc_stable.c | 9 +++------
>> 1 file changed, 3 insertions(+), 6 deletions(-)
>>
>> diff --git a/drivers/parisc/pdc_stable.c b/drivers/parisc/pdc_stable.c
>> index d6af5726ddf3..d3075445260b 100644
>> --- a/drivers/parisc/pdc_stable.c
>> +++ b/drivers/parisc/pdc_stable.c
>> @@ -274,8 +274,7 @@ pdcspath_hwpath_write(struct pdcspath_entry *entry,
>> const char *buf, size_t coun
>>
>> /* We'll use a local copy of buf */
>> count = min_t(size_t, count, sizeof(in)-1);
>> - strncpy(in, buf, count);
>> - in[count] = '\0';
>> + strscpy(in, buf, sizeof(in));
>
> What is "count" now needed for? Looks like a write only variable at least in
> these hunks.

isn't count the return value?

Helge