Commit c7b27c37 authored by Yonghong Song's avatar Yonghong Song Committed by Daniel Borkmann
Browse files

bpf: add bpffs pretty print for percpu arraymap/hash/lru_hash 



Added bpffs pretty print for percpu arraymap, percpu hashmap
and percpu lru hashmap.

For each map <key, value> pair, the format is:
   <key_value>: {
	cpu0: <value_on_cpu0>
	cpu1: <value_on_cpu1>
	...
	cpun: <value_on_cpun>
   }

For example, on my VM, there are 4 cpus, and
for test_btf test in the next patch:
   cat /sys/fs/bpf/pprint_test_percpu_hash

You may get:
   ...
   43602: {
	cpu0: {43602,0,-43602,0x3,0xaa52,0x3,{43602|[82,170,0,0,0,0,0,0]},ENUM_TWO}
	cpu1: {43602,0,-43602,0x3,0xaa52,0x3,{43602|[82,170,0,0,0,0,0,0]},ENUM_TWO}
	cpu2: {43602,0,-43602,0x3,0xaa52,0x3,{43602|[82,170,0,0,0,0,0,0]},ENUM_TWO}
	cpu3: {43602,0,-43602,0x3,0xaa52,0x3,{43602|[82,170,0,0,0,0,0,0]},ENUM_TWO}
   }
   72847: {
	cpu0: {72847,0,-72847,0x3,0x11c8f,0x3,{72847|[143,28,1,0,0,0,0,0]},ENUM_THREE}
	cpu1: {72847,0,-72847,0x3,0x11c8f,0x3,{72847|[143,28,1,0,0,0,0,0]},ENUM_THREE}
	cpu2: {72847,0,-72847,0x3,0x11c8f,0x3,{72847|[143,28,1,0,0,0,0,0]},ENUM_THREE}
	cpu3: {72847,0,-72847,0x3,0x11c8f,0x3,{72847|[143,28,1,0,0,0,0,0]},ENUM_THREE}
   }
   ...

Signed-off-by: default avatarYonghong Song <yhs@fb.com>
Signed-off-by: default avatarDaniel Borkmann <daniel@iogearbox.net>
parent 234dbe3d

kernel/bpf/arraymap.c

+24 −0
Original line number Diff line number Diff line
@@ -358,6 +358,29 @@ static void array_map_seq_show_elem(struct bpf_map *map, void *key, 
	rcu_read_unlock();

}



static void percpu_array_map_seq_show_elem(struct bpf_map *map, void *key,

					   struct seq_file *m)

{

	struct bpf_array *array = container_of(map, struct bpf_array, map);

	u32 index = *(u32 *)key;

	void __percpu *pptr;

	int cpu;



	rcu_read_lock();



	seq_printf(m, "%u: {\n", *(u32 *)key);

	pptr = array->pptrs[index & array->index_mask];

	for_each_possible_cpu(cpu) {

		seq_printf(m, "\tcpu%d: ", cpu);

		btf_type_seq_show(map->btf, map->btf_value_type_id,

				  per_cpu_ptr(pptr, cpu), m);

		seq_puts(m, "\n");

	}

	seq_puts(m, "}\n");



	rcu_read_unlock();

}



static int array_map_check_btf(const struct bpf_map *map,

			       const struct btf_type *key_type,

			       const struct btf_type *value_type)
@@ -398,6 +421,7 @@ const struct bpf_map_ops percpu_array_map_ops = { 
	.map_lookup_elem = percpu_array_map_lookup_elem,

	.map_update_elem = array_map_update_elem,

	.map_delete_elem = array_map_delete_elem,

	.map_seq_show_elem = percpu_array_map_seq_show_elem,

	.map_check_btf = array_map_check_btf,

};

kernel/bpf/hashtab.c

+31 −0
Original line number Diff line number Diff line
@@ -1285,6 +1285,35 @@ int bpf_percpu_hash_update(struct bpf_map *map, void *key, void *value, 
	return ret;

}



static void htab_percpu_map_seq_show_elem(struct bpf_map *map, void *key,

					  struct seq_file *m)

{

	struct htab_elem *l;

	void __percpu *pptr;

	int cpu;



	rcu_read_lock();



	l = __htab_map_lookup_elem(map, key);

	if (!l) {

		rcu_read_unlock();

		return;

	}



	btf_type_seq_show(map->btf, map->btf_key_type_id, key, m);

	seq_puts(m, ": {\n");

	pptr = htab_elem_get_ptr(l, map->key_size);

	for_each_possible_cpu(cpu) {

		seq_printf(m, "\tcpu%d: ", cpu);

		btf_type_seq_show(map->btf, map->btf_value_type_id,

				  per_cpu_ptr(pptr, cpu), m);

		seq_puts(m, "\n");

	}

	seq_puts(m, "}\n");



	rcu_read_unlock();

}



const struct bpf_map_ops htab_percpu_map_ops = {

	.map_alloc_check = htab_map_alloc_check,

	.map_alloc = htab_map_alloc,
@@ -1293,6 +1322,7 @@ const struct bpf_map_ops htab_percpu_map_ops = { 
	.map_lookup_elem = htab_percpu_map_lookup_elem,

	.map_update_elem = htab_percpu_map_update_elem,

	.map_delete_elem = htab_map_delete_elem,

	.map_seq_show_elem = htab_percpu_map_seq_show_elem,

};



const struct bpf_map_ops htab_lru_percpu_map_ops = {
@@ -1303,6 +1333,7 @@ const struct bpf_map_ops htab_lru_percpu_map_ops = { 
	.map_lookup_elem = htab_lru_percpu_map_lookup_elem,

	.map_update_elem = htab_lru_percpu_map_update_elem,

	.map_delete_elem = htab_lru_map_delete_elem,

	.map_seq_show_elem = htab_percpu_map_seq_show_elem,

};



static int fd_htab_map_alloc_check(union bpf_attr *attr)

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