2014-10-16 21:15:14

by Rickard Strandqvist

Subject: [PATCH v5] char: hw_random: core.c: Changed from using strncat to strlcat

The buf is used to hold the list of hwrng devices registered.
The old code ensures we don't walk off the end of buf as we
fill it, but it's unnecessarily complicated and thus difficult
to maintain. Simplify it by using strlcat.

Signed-off-by: Rickard Strandqvist <[email protected]>
Reviewed-by: Jason Cooper <[email protected]>
---
drivers/char/hw_random/core.c | 12 ++++--------
1 file changed, 4 insertions(+), 8 deletions(-)

diff --git a/drivers/char/hw_random/core.c b/drivers/char/hw_random/core.c
index aa30a25..1500cfd 100644
--- a/drivers/char/hw_random/core.c
+++ b/drivers/char/hw_random/core.c
@@ -281,7 +281,6 @@ static ssize_t hwrng_attr_available_show(struct device *dev,
char *buf)
{
int err;
- ssize_t ret = 0;
struct hwrng *rng;

err = mutex_lock_interruptible(&rng_mutex);
@@ -289,16 +288,13 @@ static ssize_t hwrng_attr_available_show(struct device *dev,
return -ERESTARTSYS;
buf[0] = '\0';
list_for_each_entry(rng, &rng_list, list) {
- strncat(buf, rng->name, PAGE_SIZE - ret - 1);
- ret += strlen(rng->name);
- strncat(buf, " ", PAGE_SIZE - ret - 1);
- ret++;
+ strlcat(buf, rng->name, PAGE_SIZE);
+ strlcat(buf, " ", PAGE_SIZE);
}
- strncat(buf, "\n", PAGE_SIZE - ret - 1);
- ret++;
+ strlcat(buf, "\n", PAGE_SIZE);
mutex_unlock(&rng_mutex);

- return ret;
+ return strlen(buf);
}

static DEVICE_ATTR(rng_current, S_IRUGO | S_IWUSR,
--
1.7.10.4

2014-10-24 14:55:56

by Herbert Xu

Subject: Re: [PATCH v5] char: hw_random: core.c: Changed from using strncat to strlcat

On Thu, Oct 16, 2014 at 11:17:23PM +0200, Rickard Strandqvist wrote:
> The buf is used to hold the list of hwrng devices registered.
> The old code ensures we don't walk off the end of buf as we
> fill it, but it's unnecessarily complicated and thus difficult
> to maintain. Simplify it by using strlcat.
>
> Signed-off-by: Rickard Strandqvist <[email protected]>
> Reviewed-by: Jason Cooper <[email protected]>

Patch applied. Thanks!
--
Email: Herbert Xu <[email protected]>
Home Page: http://gondor.apana.org.au/~herbert/
PGP Key: http://gondor.apana.org.au/~herbert/pubkey.txt