2021-01-27 00:39:12

by Paul Gortmaker

Subject: [PATCH 4/8] lib: bitmap: move ERANGE check from set_region to check_region

It makes sense to do all the checks in check_region() and not 1/2
in check_region and 1/2 in set_region.

Since set_region is called immediately after check_region, the net
effect on runtime is zero, but it gets rid of an if (...) return...

Cc: Yury Norov <[email protected]>
Cc: Rasmus Villemoes <[email protected]>
Cc: Andy Shevchenko <[email protected]>
Signed-off-by: Paul Gortmaker <[email protected]>
---
lib/bitmap.c | 14 +++++---------
1 file changed, 5 insertions(+), 9 deletions(-)

diff --git a/lib/bitmap.c b/lib/bitmap.c
index 162e2850c622..833f152a2c43 100644
--- a/lib/bitmap.c
+++ b/lib/bitmap.c
@@ -500,17 +500,12 @@ struct region {
unsigned int nbits;
};

-static int bitmap_set_region(const struct region *r, unsigned long *bitmap)
+static void bitmap_set_region(const struct region *r, unsigned long *bitmap)
{
unsigned int start;

- if (r->end >= r->nbits)
- return -ERANGE;
-
for (start = r->start; start <= r->end; start += r->group_len)
bitmap_set(bitmap, start, min(r->end - start + 1, r->off));
-
- return 0;
}

static int bitmap_check_region(const struct region *r)
@@ -518,6 +513,9 @@ static int bitmap_check_region(const struct region *r)
if (r->start > r->end || r->group_len == 0 || r->off > r->group_len)
return -EINVAL;

+ if (r->end >= r->nbits)
+ return -ERANGE;
+
return 0;
}

@@ -656,9 +654,7 @@ int bitmap_parselist(const char *buf, unsigned long *maskp, int nmaskbits)
if (ret)
return ret;

- ret = bitmap_set_region(&r, maskp);
- if (ret)
- return ret;
+ bitmap_set_region(&r, maskp);
}

return 0;
--
2.17.1

2021-01-27 19:54:12

by Andy Shevchenko

Subject: Re: [PATCH 4/8] lib: bitmap: move ERANGE check from set_region to check_region

On Tue, Jan 26, 2021 at 12:11:37PM -0500, Paul Gortmaker wrote:
> It makes sense to do all the checks in check_region() and not 1/2
> in check_region and 1/2 in set_region.
>
> Since set_region is called immediately after check_region, the net
> effect on runtime is zero, but it gets rid of an if (...) return...

Like it!
Reviewed-by: Andy Shevchenko <[email protected]>

> Cc: Yury Norov <[email protected]>
> Cc: Rasmus Villemoes <[email protected]>
> Cc: Andy Shevchenko <[email protected]>
> Signed-off-by: Paul Gortmaker <[email protected]>
> ---
> lib/bitmap.c | 14 +++++---------
> 1 file changed, 5 insertions(+), 9 deletions(-)
>
> diff --git a/lib/bitmap.c b/lib/bitmap.c
> index 162e2850c622..833f152a2c43 100644
> --- a/lib/bitmap.c
> +++ b/lib/bitmap.c
> @@ -500,17 +500,12 @@ struct region {
> unsigned int nbits;
> };
>
> -static int bitmap_set_region(const struct region *r, unsigned long *bitmap)
> +static void bitmap_set_region(const struct region *r, unsigned long *bitmap)
> {
> unsigned int start;
>
> - if (r->end >= r->nbits)
> - return -ERANGE;
> -
> for (start = r->start; start <= r->end; start += r->group_len)
> bitmap_set(bitmap, start, min(r->end - start + 1, r->off));
> -
> - return 0;
> }
>
> static int bitmap_check_region(const struct region *r)
> @@ -518,6 +513,9 @@ static int bitmap_check_region(const struct region *r)
> if (r->start > r->end || r->group_len == 0 || r->off > r->group_len)
> return -EINVAL;
>
> + if (r->end >= r->nbits)
> + return -ERANGE;
> +
> return 0;
> }
>
> @@ -656,9 +654,7 @@ int bitmap_parselist(const char *buf, unsigned long *maskp, int nmaskbits)
> if (ret)
> return ret;
>
> - ret = bitmap_set_region(&r, maskp);
> - if (ret)
> - return ret;
> + bitmap_set_region(&r, maskp);
> }
>
> return 0;
> --
> 2.17.1
>

--
With Best Regards,
Andy Shevchenko

2021-01-27 21:29:07

by Yury Norov

Subject: Re: [PATCH 4/8] lib: bitmap: move ERANGE check from set_region to check_region

On Tue, Jan 26, 2021 at 9:12 AM Paul Gortmaker
<[email protected]> wrote:
>
> It makes sense to do all the checks in check_region() and not 1/2
> in check_region and 1/2 in set_region.
>
> Since set_region is called immediately after check_region, the net
> effect on runtime is zero, but it gets rid of an if (...) return...
>
> Cc: Yury Norov <[email protected]>
> Cc: Rasmus Villemoes <[email protected]>
> Cc: Andy Shevchenko <[email protected]>
> Signed-off-by: Paul Gortmaker <[email protected]>
> ---
> lib/bitmap.c | 14 +++++---------
> 1 file changed, 5 insertions(+), 9 deletions(-)
>
> diff --git a/lib/bitmap.c b/lib/bitmap.c
> index 162e2850c622..833f152a2c43 100644
> --- a/lib/bitmap.c
> +++ b/lib/bitmap.c
> @@ -500,17 +500,12 @@ struct region {
> unsigned int nbits;
> };
>
> -static int bitmap_set_region(const struct region *r, unsigned long *bitmap)
> +static void bitmap_set_region(const struct region *r, unsigned long *bitmap)
> {
> unsigned int start;
>
> - if (r->end >= r->nbits)
> - return -ERANGE;
> -
> for (start = r->start; start <= r->end; start += r->group_len)
> bitmap_set(bitmap, start, min(r->end - start + 1, r->off));
> -
> - return 0;
> }
>
> static int bitmap_check_region(const struct region *r)
> @@ -518,6 +513,9 @@ static int bitmap_check_region(const struct region *r)
> if (r->start > r->end || r->group_len == 0 || r->off > r->group_len)
> return -EINVAL;
>
> + if (r->end >= r->nbits)
> + return -ERANGE;
> +
> return 0;
> }
>
> @@ -656,9 +654,7 @@ int bitmap_parselist(const char *buf, unsigned long *maskp, int nmaskbits)
> if (ret)
> return ret;
>
> - ret = bitmap_set_region(&r, maskp);
> - if (ret)
> - return ret;
> + bitmap_set_region(&r, maskp);
> }
>
> return 0;
> --
> 2.17.1

Acked-by: Yury Norov <[email protected]>