2020-05-06 20:57:31

by Ian Rogers

Subject: [PATCH 2/2] lib/bpf hashmap: fixes to hashmap__clear

hashmap_find_entry assumes that if buckets is NULL then there are no
entries. NULL the buckets in clear to ensure this.
Free hashmap entries and not just the bucket array.

Signed-off-by: Ian Rogers <[email protected]>
---
tools/lib/bpf/hashmap.c | 6 ++++++
1 file changed, 6 insertions(+)

diff --git a/tools/lib/bpf/hashmap.c b/tools/lib/bpf/hashmap.c
index 54c30c802070..1a1bca1ff5cd 100644
--- a/tools/lib/bpf/hashmap.c
+++ b/tools/lib/bpf/hashmap.c
@@ -59,7 +59,13 @@ struct hashmap *hashmap__new(hashmap_hash_fn hash_fn,

void hashmap__clear(struct hashmap *map)
{
+ struct hashmap_entry *cur, *tmp;
+ size_t bkt;
+
+ hashmap__for_each_entry_safe(map, cur, tmp, bkt)
+ free(cur);
free(map->buckets);
+ map->buckets = NULL;
map->cap = map->cap_bits = map->sz = 0;
}

--
2.26.2.526.g744177e7f7-goog

2020-05-06 21:38:39

by Andrii Nakryiko

Subject: Re: [PATCH 2/2] lib/bpf hashmap: fixes to hashmap__clear

On Wed, May 6, 2020 at 1:55 PM Ian Rogers <[email protected]> wrote:
>
> hashmap_find_entry assumes that if buckets is NULL then there are no
> entries. NULL the buckets in clear to ensure this.
> Free hashmap entries and not just the bucket array.
>
> Signed-off-by: Ian Rogers <[email protected]>
> ---

This is already fixed in bpf-next ([0]). Seems to be 1-to-1 character
by character :)

[0] https://patchwork.ozlabs.org/project/netdev/patch/[email protected]/

> tools/lib/bpf/hashmap.c | 6 ++++++
> 1 file changed, 6 insertions(+)
>
> diff --git a/tools/lib/bpf/hashmap.c b/tools/lib/bpf/hashmap.c
> index 54c30c802070..1a1bca1ff5cd 100644
> --- a/tools/lib/bpf/hashmap.c
> +++ b/tools/lib/bpf/hashmap.c
> @@ -59,7 +59,13 @@ struct hashmap *hashmap__new(hashmap_hash_fn hash_fn,
>
> void hashmap__clear(struct hashmap *map)
> {
> + struct hashmap_entry *cur, *tmp;
> + size_t bkt;
> +
> + hashmap__for_each_entry_safe(map, cur, tmp, bkt)
> + free(cur);
> free(map->buckets);
> + map->buckets = NULL;
> map->cap = map->cap_bits = map->sz = 0;
> }
>
> --
> 2.26.2.526.g744177e7f7-goog
>

2020-05-06 21:55:41

by Ian Rogers

Subject: Re: [PATCH 2/2] lib/bpf hashmap: fixes to hashmap__clear

On Wed, May 6, 2020 at 2:36 PM Andrii Nakryiko
<[email protected]> wrote:
>
> On Wed, May 6, 2020 at 1:55 PM Ian Rogers <[email protected]> wrote:
> >
> > hashmap_find_entry assumes that if buckets is NULL then there are no
> > entries. NULL the buckets in clear to ensure this.
> > Free hashmap entries and not just the bucket array.
> >
> > Signed-off-by: Ian Rogers <[email protected]>
> > ---
>
> This is already fixed in bpf-next ([0]). Seems to be 1-to-1 character
> by character :)
>
> [0] https://patchwork.ozlabs.org/project/netdev/patch/[email protected]/

Thanks!
Ian

> > tools/lib/bpf/hashmap.c | 6 ++++++
> > 1 file changed, 6 insertions(+)
> >
> > diff --git a/tools/lib/bpf/hashmap.c b/tools/lib/bpf/hashmap.c
> > index 54c30c802070..1a1bca1ff5cd 100644
> > --- a/tools/lib/bpf/hashmap.c
> > +++ b/tools/lib/bpf/hashmap.c
> > @@ -59,7 +59,13 @@ struct hashmap *hashmap__new(hashmap_hash_fn hash_fn,
> >
> > void hashmap__clear(struct hashmap *map)
> > {
> > + struct hashmap_entry *cur, *tmp;
> > + size_t bkt;
> > +
> > + hashmap__for_each_entry_safe(map, cur, tmp, bkt)
> > + free(cur);
> > free(map->buckets);
> > + map->buckets = NULL;
> > map->cap = map->cap_bits = map->sz = 0;
> > }
> >
> > --
> > 2.26.2.526.g744177e7f7-goog
> >