maps__merge_in() hard codes the steps to free the maps_by_name list. It
seems to not map__put() each element before freeing, and it sets
maps_by_name_sorted to true after freeing, which may be harmless but
is inconsistent with maps__init() and other functions.

maps__maps_by_name_addr() is also quite hard to read because we already
have maps__maps_by_name() and maps__maps_by_address(), but the function
is only used in that place so delete it.

Signed-off-by: James Clark <james.clark@arm.com>
---
 tools/perf/util/maps.c | 14 +++++++-------
 1 file changed, 7 insertions(+), 7 deletions(-)

diff --git a/tools/perf/util/maps.c b/tools/perf/util/maps.c
index 61eb742d91e3..16b39db594f4 100644
--- a/tools/perf/util/maps.c
+++ b/tools/perf/util/maps.c
@@ -124,11 +124,6 @@ static void maps__set_maps_by_address(struct maps *maps, struct map **new)
 
 }
 
-static struct map ***maps__maps_by_name_addr(struct maps *maps)
-{
-	return &RC_CHK_ACCESS(maps)->maps_by_name;
-}
-
 static void maps__set_nr_maps_allocated(struct maps *maps, unsigned int nr_maps_allocated)
 {
 	RC_CHK_ACCESS(maps)->nr_maps_allocated = nr_maps_allocated;
@@ -284,6 +279,9 @@ void maps__put(struct maps *maps)
 
 static void __maps__free_maps_by_name(struct maps *maps)
 {
+	if (!maps__maps_by_name(maps))
+		return;
+
 	/*
 	 * Free everything to try to do it from the rbtree in the next search
 	 */
@@ -291,6 +289,9 @@ static void __maps__free_maps_by_name(struct maps *maps)
 		map__put(maps__maps_by_name(maps)[i]);
 
 	zfree(&RC_CHK_ACCESS(maps)->maps_by_name);
+
+	/* Consistent with maps__init(). When maps_by_name == NULL, maps_by_name_sorted == false */
+	maps__set_maps_by_name_sorted(maps, false);
 }
 
 static int map__start_cmp(const void *a, const void *b)
@@ -1167,8 +1168,7 @@ int maps__merge_in(struct maps *kmaps, struct map *new_map)
 	}
 	maps__set_maps_by_address(kmaps, merged_maps_by_address);
 	maps__set_maps_by_address_sorted(kmaps, true);
-	zfree(maps__maps_by_name_addr(kmaps));
-	maps__set_maps_by_name_sorted(kmaps, true);
+	__maps__free_maps_by_name(kmaps);
 	maps__set_nr_maps_allocated(kmaps, merged_nr_maps_allocated);
 
 	/* Copy entries before the new_map that can't overlap. */
-- 
2.34.1

On Tue, May 7, 2024 at 7:13 AM James Clark <james.clark@arm.com> wrote:
>
> maps__merge_in() hard codes the steps to free the maps_by_name list. It
> seems to not map__put() each element before freeing, and it sets
> maps_by_name_sorted to true after freeing, which may be harmless but
> is inconsistent with maps__init() and other functions.
>
> maps__maps_by_name_addr() is also quite hard to read because we already
> have maps__maps_by_name() and maps__maps_by_address(), but the function
> is only used in that place so delete it.
>
> Signed-off-by: James Clark <james.clark@arm.com>
> ---
>  tools/perf/util/maps.c | 14 +++++++-------
>  1 file changed, 7 insertions(+), 7 deletions(-)
>
> diff --git a/tools/perf/util/maps.c b/tools/perf/util/maps.c
> index 61eb742d91e3..16b39db594f4 100644
> --- a/tools/perf/util/maps.c
> +++ b/tools/perf/util/maps.c
> @@ -124,11 +124,6 @@ static void maps__set_maps_by_address(struct maps *maps, struct map **new)
>
>  }
>
> -static struct map ***maps__maps_by_name_addr(struct maps *maps)
> -{
> -       return &RC_CHK_ACCESS(maps)->maps_by_name;
> -}
> -
>  static void maps__set_nr_maps_allocated(struct maps *maps, unsigned int nr_maps_allocated)
>  {
>         RC_CHK_ACCESS(maps)->nr_maps_allocated = nr_maps_allocated;
> @@ -284,6 +279,9 @@ void maps__put(struct maps *maps)
>
>  static void __maps__free_maps_by_name(struct maps *maps)
>  {
> +       if (!maps__maps_by_name(maps))
> +               return;
> +
>         /*
>          * Free everything to try to do it from the rbtree in the next search

nit: this comment is stale, it should be maps_by_address rather than the rbtree.

Reviewed-by: Ian Rogers <irogers@google.com>

Thanks,
Ian

>          */
> @@ -291,6 +289,9 @@ static void __maps__free_maps_by_name(struct maps *maps)
>                 map__put(maps__maps_by_name(maps)[i]);
>
>         zfree(&RC_CHK_ACCESS(maps)->maps_by_name);
> +
> +       /* Consistent with maps__init(). When maps_by_name == NULL, maps_by_name_sorted == false */
> +       maps__set_maps_by_name_sorted(maps, false);
>  }
>
>  static int map__start_cmp(const void *a, const void *b)
> @@ -1167,8 +1168,7 @@ int maps__merge_in(struct maps *kmaps, struct map *new_map)
>         }
>         maps__set_maps_by_address(kmaps, merged_maps_by_address);
>         maps__set_maps_by_address_sorted(kmaps, true);
> -       zfree(maps__maps_by_name_addr(kmaps));
> -       maps__set_maps_by_name_sorted(kmaps, true);
> +       __maps__free_maps_by_name(kmaps);
>         maps__set_nr_maps_allocated(kmaps, merged_nr_maps_allocated);
>
>         /* Copy entries before the new_map that can't overlap. */
> --
> 2.34.1
>

On Tue, May 7, 2024 at 7:13 AM James Clark <james.clark@arm.com> wrote:
>
> maps__merge_in() hard codes the steps to free the maps_by_name list. It
> seems to not map__put() each element before freeing, and it sets
> maps_by_name_sorted to true after freeing, which may be harmless but
> is inconsistent with maps__init() and other functions.
>
> maps__maps_by_name_addr() is also quite hard to read because we already
> have maps__maps_by_name() and maps__maps_by_address(), but the function
> is only used in that place so delete it.

Agreed, I feel like we need some more cleanup here.

Thanks,
Namhyung


>
> Signed-off-by: James Clark <james.clark@arm.com>
> ---
>  tools/perf/util/maps.c | 14 +++++++-------
>  1 file changed, 7 insertions(+), 7 deletions(-)
>
> diff --git a/tools/perf/util/maps.c b/tools/perf/util/maps.c
> index 61eb742d91e3..16b39db594f4 100644
> --- a/tools/perf/util/maps.c
> +++ b/tools/perf/util/maps.c
> @@ -124,11 +124,6 @@ static void maps__set_maps_by_address(struct maps *maps, struct map **new)
>
>  }
>
> -static struct map ***maps__maps_by_name_addr(struct maps *maps)
> -{
> -       return &RC_CHK_ACCESS(maps)->maps_by_name;
> -}
> -
>  static void maps__set_nr_maps_allocated(struct maps *maps, unsigned int nr_maps_allocated)
>  {
>         RC_CHK_ACCESS(maps)->nr_maps_allocated = nr_maps_allocated;
> @@ -284,6 +279,9 @@ void maps__put(struct maps *maps)
>
>  static void __maps__free_maps_by_name(struct maps *maps)
>  {
> +       if (!maps__maps_by_name(maps))
> +               return;
> +
>         /*
>          * Free everything to try to do it from the rbtree in the next search
>          */
> @@ -291,6 +289,9 @@ static void __maps__free_maps_by_name(struct maps *maps)
>                 map__put(maps__maps_by_name(maps)[i]);
>
>         zfree(&RC_CHK_ACCESS(maps)->maps_by_name);
> +
> +       /* Consistent with maps__init(). When maps_by_name == NULL, maps_by_name_sorted == false */
> +       maps__set_maps_by_name_sorted(maps, false);
>  }
>
>  static int map__start_cmp(const void *a, const void *b)
> @@ -1167,8 +1168,7 @@ int maps__merge_in(struct maps *kmaps, struct map *new_map)
>         }
>         maps__set_maps_by_address(kmaps, merged_maps_by_address);
>         maps__set_maps_by_address_sorted(kmaps, true);
> -       zfree(maps__maps_by_name_addr(kmaps));
> -       maps__set_maps_by_name_sorted(kmaps, true);
> +       __maps__free_maps_by_name(kmaps);
>         maps__set_nr_maps_allocated(kmaps, merged_nr_maps_allocated);
>
>         /* Copy entries before the new_map that can't overlap. */
> --
> 2.34.1
>