[PATCH bpf v4 2/2] selftest/bpf: Add map_in_maps with BPF_MAP_TYPE_PERF_EVENT_ARRAY values

[PATCH bpf v4 2/2] selftest/bpf: Add map_in_maps with BPF_MAP_TYPE_PERF_EVENT_ARRAY values

[Andrey Grafin]

Check that bpf_object__load() successfully creates map_in_maps
with BPF_MAP_TYPE_PERF_EVENT_ARRAY values.
This changes cover fix in the commit 912884275669
("libbpf: Apply map_set_def_max_entries() for inner_maps on creation").

A command line output is:
- w/o fix
$ sudo ./test_maps
libbpf: map 'mim_array_pe': failed to create inner map: -22
libbpf: map 'mim_array_pe': failed to create: Invalid argument(-22)
libbpf: failed to load object './test_map_in_map.bpf.o'
Failed to load test prog

- with fix
$ sudo ./test_maps
...
test_maps: OK, 0 SKIPPED

Signed-off-by: Andrey Grafin <conquistador@yandex-team.ru>
---
 .../selftests/bpf/progs/test_map_in_map.c     | 23 +++++++++++++++++++
 tools/testing/selftests/bpf/test_maps.c       |  6 ++++-
 2 files changed, 28 insertions(+), 1 deletion(-)

diff --git a/tools/testing/selftests/bpf/progs/test_map_in_map.c b/tools/testing/selftests/bpf/progs/test_map_in_map.c
index f416032ba858..54ce1f4bdc7b 100644
--- a/tools/testing/selftests/bpf/progs/test_map_in_map.c
+++ b/tools/testing/selftests/bpf/progs/test_map_in_map.c
@@ -21,6 +21,29 @@ struct {
 	__type(value, __u32);
 } mim_hash SEC(".maps");
 
+struct perf_event_array {
+	__uint(type, BPF_MAP_TYPE_PERF_EVENT_ARRAY);
+	__type(key, __u32);
+	__type(value, __u32);
+} inner_map0 SEC(".maps"), inner_map1 SEC(".maps");
+
+struct {
+	__uint(type, BPF_MAP_TYPE_ARRAY_OF_MAPS);
+	__uint(max_entries, 2);
+	__type(key, __u32);
+	__array(values, struct perf_event_array);
+} mim_array_pe SEC(".maps") = {
+	.values = {&inner_map0, &inner_map1}};
+
+struct {
+	__uint(type, BPF_MAP_TYPE_HASH_OF_MAPS);
+	__uint(max_entries, 1);
+	__type(key, __u32);
+	__array(values, struct perf_event_array);
+} mim_hash_pe SEC(".maps") = {
+	.values = {&inner_map0}};
+
+
 SEC("xdp")
 int xdp_mimtest0(struct xdp_md *ctx)
 {
diff --git a/tools/testing/selftests/bpf/test_maps.c b/tools/testing/selftests/bpf/test_maps.c
index 7fc00e423e4d..e0dd101c9f2b 100644
--- a/tools/testing/selftests/bpf/test_maps.c
+++ b/tools/testing/selftests/bpf/test_maps.c
@@ -1190,7 +1190,11 @@ static void test_map_in_map(void)
 		goto out_map_in_map;
 	}
 
-	bpf_object__load(obj);
+	err = bpf_object__load(obj);
+	if (err) {
+		printf("Failed to load test prog\n");
+		goto out_map_in_map;
+	}
 
 	map = bpf_object__find_map_by_name(obj, "mim_array");
 	if (!map) {
-- 
2.41.0

[PATCH bpf v4 1/2] libbpf: Apply map_set_def_max_entries() for inner_maps on creation

[Andrey Grafin]

This patch allows to auto create BPF_MAP_TYPE_ARRAY_OF_MAPS and
BPF_MAP_TYPE_HASH_OF_MAPS with values of BPF_MAP_TYPE_PERF_EVENT_ARRAY
by bpf_object__load().

Previous behaviour created a zero filled btf_map_def for inner maps and
tried to use it for a map creation but the linux kernel forbids to create
a BPF_MAP_TYPE_PERF_EVENT_ARRAY map with max_entries=0.

Signed-off-by: Andrey Grafin <conquistador@yandex-team.ru>
---
 tools/lib/bpf/libbpf.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c
index e067be95da3c..8f4d580187aa 100644
--- a/tools/lib/bpf/libbpf.c
+++ b/tools/lib/bpf/libbpf.c
@@ -70,6 +70,7 @@
 
 static struct bpf_map *bpf_object__add_map(struct bpf_object *obj);
 static bool prog_is_subprog(const struct bpf_object *obj, const struct bpf_program *prog);
+static int map_set_def_max_entries(struct bpf_map *map);
 
 static const char * const attach_type_name[] = {
 	[BPF_CGROUP_INET_INGRESS]	= "cgroup_inet_ingress",
@@ -5212,6 +5213,9 @@ static int bpf_object__create_map(struct bpf_object *obj, struct bpf_map *map, b
 
 	if (bpf_map_type__is_map_in_map(def->type)) {
 		if (map->inner_map) {
+			err = map_set_def_max_entries(map->inner_map);
+			if (err)
+				return err;
 			err = bpf_object__create_map(obj, map->inner_map, true);
 			if (err) {
 				pr_warn("map '%s': failed to create inner map: %d\n",
-- 
2.41.0

[PATCH bpf v4 2/2] selftest/bpf: Add map_in_maps with BPF_MAP_TYPE_PERF_EVENT_ARRAY values

[Andrey Grafin]

Check that bpf_object__load() successfully creates map_in_maps
with BPF_MAP_TYPE_PERF_EVENT_ARRAY values.
These changes cover fix in the previous patch
"libbpf: Apply map_set_def_max_entries() for inner_maps on creation".

A command line output is:
- w/o fix
$ sudo ./test_maps
libbpf: map 'mim_array_pe': failed to create inner map: -22
libbpf: map 'mim_array_pe': failed to create: Invalid argument(-22)
libbpf: failed to load object './test_map_in_map.bpf.o'
Failed to load test prog

- with fix
$ sudo ./test_maps
...
test_maps: OK, 0 SKIPPED

Signed-off-by: Andrey Grafin <conquistador@yandex-team.ru>
---
 .../selftests/bpf/progs/test_map_in_map.c     | 23 +++++++++++++++++++
 tools/testing/selftests/bpf/test_maps.c       |  6 ++++-
 2 files changed, 28 insertions(+), 1 deletion(-)

diff --git a/tools/testing/selftests/bpf/progs/test_map_in_map.c b/tools/testing/selftests/bpf/progs/test_map_in_map.c
index f416032ba858..54ce1f4bdc7b 100644
--- a/tools/testing/selftests/bpf/progs/test_map_in_map.c
+++ b/tools/testing/selftests/bpf/progs/test_map_in_map.c
@@ -21,6 +21,29 @@ struct {
 	__type(value, __u32);
 } mim_hash SEC(".maps");
 
+struct perf_event_array {
+	__uint(type, BPF_MAP_TYPE_PERF_EVENT_ARRAY);
+	__type(key, __u32);
+	__type(value, __u32);
+} inner_map0 SEC(".maps"), inner_map1 SEC(".maps");
+
+struct {
+	__uint(type, BPF_MAP_TYPE_ARRAY_OF_MAPS);
+	__uint(max_entries, 2);
+	__type(key, __u32);
+	__array(values, struct perf_event_array);
+} mim_array_pe SEC(".maps") = {
+	.values = {&inner_map0, &inner_map1}};
+
+struct {
+	__uint(type, BPF_MAP_TYPE_HASH_OF_MAPS);
+	__uint(max_entries, 1);
+	__type(key, __u32);
+	__array(values, struct perf_event_array);
+} mim_hash_pe SEC(".maps") = {
+	.values = {&inner_map0}};
+
+
 SEC("xdp")
 int xdp_mimtest0(struct xdp_md *ctx)
 {
diff --git a/tools/testing/selftests/bpf/test_maps.c b/tools/testing/selftests/bpf/test_maps.c
index 7fc00e423e4d..e0dd101c9f2b 100644
--- a/tools/testing/selftests/bpf/test_maps.c
+++ b/tools/testing/selftests/bpf/test_maps.c
@@ -1190,7 +1190,11 @@ static void test_map_in_map(void)
 		goto out_map_in_map;
 	}
 
-	bpf_object__load(obj);
+	err = bpf_object__load(obj);
+	if (err) {
+		printf("Failed to load test prog\n");
+		goto out_map_in_map;
+	}
 
 	map = bpf_object__find_map_by_name(obj, "mim_array");
 	if (!map) {
-- 
2.41.0

Re: [PATCH bpf v4 1/2] libbpf: Apply map_set_def_max_entries() for inner_maps on creation

[Yonghong Song]

On 1/16/24 6:01 AM, Andrey Grafin wrote:
> This patch allows to auto create BPF_MAP_TYPE_ARRAY_OF_MAPS and
> BPF_MAP_TYPE_HASH_OF_MAPS with values of BPF_MAP_TYPE_PERF_EVENT_ARRAY
> by bpf_object__load().
>
> Previous behaviour created a zero filled btf_map_def for inner maps and
> tried to use it for a map creation but the linux kernel forbids to create
> a BPF_MAP_TYPE_PERF_EVENT_ARRAY map with max_entries=0.
>
> Signed-off-by: Andrey Grafin <conquistador@yandex-team.ru>

Acked-by: Yonghong Song <yonghong.song@linux.dev>

Re: [PATCH bpf v4 2/2] selftest/bpf: Add map_in_maps with BPF_MAP_TYPE_PERF_EVENT_ARRAY values

[Yonghong Song]

On 1/16/24 6:01 AM, Andrey Grafin wrote:
> Check that bpf_object__load() successfully creates map_in_maps
> with BPF_MAP_TYPE_PERF_EVENT_ARRAY values.
> These changes cover fix in the previous patch
> "libbpf: Apply map_set_def_max_entries() for inner_maps on creation".
>
> A command line output is:
> - w/o fix
> $ sudo ./test_maps
> libbpf: map 'mim_array_pe': failed to create inner map: -22
> libbpf: map 'mim_array_pe': failed to create: Invalid argument(-22)
> libbpf: failed to load object './test_map_in_map.bpf.o'
> Failed to load test prog
>
> - with fix
> $ sudo ./test_maps
> ...
> test_maps: OK, 0 SKIPPED
>
> Signed-off-by: Andrey Grafin <conquistador@yandex-team.ru>

Ack with a nit below.

Acked-by: Yonghong Song <yonghong.song@linux.dev>

> ---
>   .../selftests/bpf/progs/test_map_in_map.c     | 23 +++++++++++++++++++
>   tools/testing/selftests/bpf/test_maps.c       |  6 ++++-
>   2 files changed, 28 insertions(+), 1 deletion(-)
>
> diff --git a/tools/testing/selftests/bpf/progs/test_map_in_map.c b/tools/testing/selftests/bpf/progs/test_map_in_map.c
> index f416032ba858..54ce1f4bdc7b 100644
> --- a/tools/testing/selftests/bpf/progs/test_map_in_map.c
> +++ b/tools/testing/selftests/bpf/progs/test_map_in_map.c
> @@ -21,6 +21,29 @@ struct {
>   	__type(value, __u32);
>   } mim_hash SEC(".maps");
>   

To avoid confusion for users looking at code why
the following three maps are not used. Maybe add
a comment below like:

/* The following three maps are used to test
  * perf_event_array map can be an inner
  * map of hash/array_of_maps.
  */

> +struct perf_event_array {
> +	__uint(type, BPF_MAP_TYPE_PERF_EVENT_ARRAY);
> +	__type(key, __u32);
> +	__type(value, __u32);
> +} inner_map0 SEC(".maps"), inner_map1 SEC(".maps");
> +
> +struct {
> +	__uint(type, BPF_MAP_TYPE_ARRAY_OF_MAPS);
> +	__uint(max_entries, 2);
> +	__type(key, __u32);
> +	__array(values, struct perf_event_array);
> +} mim_array_pe SEC(".maps") = {
> +	.values = {&inner_map0, &inner_map1}};
> +
> +struct {
> +	__uint(type, BPF_MAP_TYPE_HASH_OF_MAPS);
> +	__uint(max_entries, 1);
> +	__type(key, __u32);
> +	__array(values, struct perf_event_array);
> +} mim_hash_pe SEC(".maps") = {
> +	.values = {&inner_map0}};
> +
> +
>   SEC("xdp")
>   int xdp_mimtest0(struct xdp_md *ctx)
>   {
> diff --git a/tools/testing/selftests/bpf/test_maps.c b/tools/testing/selftests/bpf/test_maps.c
> index 7fc00e423e4d..e0dd101c9f2b 100644
> --- a/tools/testing/selftests/bpf/test_maps.c
> +++ b/tools/testing/selftests/bpf/test_maps.c
> @@ -1190,7 +1190,11 @@ static void test_map_in_map(void)
>   		goto out_map_in_map;
>   	}
>   
> -	bpf_object__load(obj);
> +	err = bpf_object__load(obj);
> +	if (err) {
> +		printf("Failed to load test prog\n");
> +		goto out_map_in_map;
> +	}
>   
>   	map = bpf_object__find_map_by_name(obj, "mim_array");
>   	if (!map) {

Re: [PATCH bpf v4 1/2] libbpf: Apply map_set_def_max_entries() for inner_maps on creation

[Hou Tao]

On 1/16/2024 10:01 PM, Andrey Grafin wrote:
> This patch allows to auto create BPF_MAP_TYPE_ARRAY_OF_MAPS and
> BPF_MAP_TYPE_HASH_OF_MAPS with values of BPF_MAP_TYPE_PERF_EVENT_ARRAY
> by bpf_object__load().
>
> Previous behaviour created a zero filled btf_map_def for inner maps and
> tried to use it for a map creation but the linux kernel forbids to create
> a BPF_MAP_TYPE_PERF_EVENT_ARRAY map with max_entries=0.
>
> Signed-off-by: Andrey Grafin <conquistador@yandex-team.ru>

Acked-by: Hou Tao <houtao1@huawei.com>

Re: [PATCH bpf v4 2/2] selftest/bpf: Add map_in_maps with BPF_MAP_TYPE_PERF_EVENT_ARRAY values

[Hou Tao]

Hi,

On 1/16/2024 10:01 PM, Andrey Grafin wrote:
> Check that bpf_object__load() successfully creates map_in_maps
> with BPF_MAP_TYPE_PERF_EVENT_ARRAY values.
> These changes cover fix in the previous patch
> "libbpf: Apply map_set_def_max_entries() for inner_maps on creation".
>
> A command line output is:
> - w/o fix
> $ sudo ./test_maps
> libbpf: map 'mim_array_pe': failed to create inner map: -22
> libbpf: map 'mim_array_pe': failed to create: Invalid argument(-22)
> libbpf: failed to load object './test_map_in_map.bpf.o'
> Failed to load test prog
>
> - with fix
> $ sudo ./test_maps
> ...
> test_maps: OK, 0 SKIPPED
>
> Signed-off-by: Andrey Grafin <conquistador@yandex-team.ru>
> ---
>  .../selftests/bpf/progs/test_map_in_map.c     | 23 +++++++++++++++++++
>  tools/testing/selftests/bpf/test_maps.c       |  6 ++++-
>  2 files changed, 28 insertions(+), 1 deletion(-)
>
> diff --git a/tools/testing/selftests/bpf/progs/test_map_in_map.c b/tools/testing/selftests/bpf/progs/test_map_in_map.c
> index f416032ba858..54ce1f4bdc7b 100644
> --- a/tools/testing/selftests/bpf/progs/test_map_in_map.c
> +++ b/tools/testing/selftests/bpf/progs/test_map_in_map.c
> @@ -21,6 +21,29 @@ struct {
>  	__type(value, __u32);
>  } mim_hash SEC(".maps");
>  
> +struct perf_event_array {
> +	__uint(type, BPF_MAP_TYPE_PERF_EVENT_ARRAY);
> +	__type(key, __u32);
> +	__type(value, __u32);
> +} inner_map0 SEC(".maps"), inner_map1 SEC(".maps");
> +
> +struct {
> +	__uint(type, BPF_MAP_TYPE_ARRAY_OF_MAPS);
> +	__uint(max_entries, 2);
> +	__type(key, __u32);
> +	__array(values, struct perf_event_array);
> +} mim_array_pe SEC(".maps") = {
> +	.values = {&inner_map0, &inner_map1}};

It seems the reproduce of the failure doesn't need two inner maps, so I
think only using one inner map just like min_hash_pe does is enough.
> +
> +struct {
> +	__uint(type, BPF_MAP_TYPE_HASH_OF_MAPS);
> +	__uint(max_entries, 1);
> +	__type(key, __u32);
> +	__array(values, struct perf_event_array);
> +} mim_hash_pe SEC(".maps") = {
> +	.values = {&inner_map0}};
> +
> +
>  SEC("xdp")
>  int xdp_mimtest0(struct xdp_md *ctx)
>  {
> diff --git a/tools/testing/selftests/bpf/test_maps.c b/tools/testing/selftests/bpf/test_maps.c
> index 7fc00e423e4d..e0dd101c9f2b 100644
> --- a/tools/testing/selftests/bpf/test_maps.c
> +++ b/tools/testing/selftests/bpf/test_maps.c
> @@ -1190,7 +1190,11 @@ static void test_map_in_map(void)
>  		goto out_map_in_map;
>  	}
>  
> -	bpf_object__load(obj);
> +	err = bpf_object__load(obj);
> +	if (err) {
> +		printf("Failed to load test prog\n");
> +		goto out_map_in_map;
> +	}
>  
>  	map = bpf_object__find_map_by_name(obj, "mim_array");
>  	if (!map) {