Commit 74b247f4 authored by Daniel Borkmann's avatar Daniel Borkmann
Browse files

Merge branch 'bpf-btf-for-htab-lru' 



Yonghong Song says:

====================
Commit a26ca7c9 ("bpf: btf: Add pretty print support to
the basic arraymap") added pretty print support to array map.
This patch adds pretty print for hash and lru_hash maps.

The following example shows the pretty-print result of a pinned
hashmap. Without this patch set, user will get an error instead.

    struct map_value {
            int count_a;
            int count_b;
    };

    cat /sys/fs/bpf/pinned_hash_map:

    87907: {87907,87908}
    57354: {37354,57355}
    76625: {76625,76626}
    ...

Patch #1 fixed a bug in bpffs map_seq_next() function so that
all elements in the hash table will be traversed.
Patch #2 implemented map_seq_show_elem() and map_check_btf()
callback functions for hash and lru hash maps.
Patch #3 enhanced tools/testing/selftests/bpf/test_btf.c to
test bpffs hash and lru hash map pretty print.
====================

Signed-off-by: default avatarDaniel Borkmann <daniel@iogearbox.net>
parents 60afdf06 af2a81da

kernel/bpf/hashtab.c

+44 −0
Original line number Diff line number Diff line
@@ -11,9 +11,11 @@ 
 * General Public License for more details.

 */

#include <linux/bpf.h>

#include <linux/btf.h>

#include <linux/jhash.h>

#include <linux/filter.h>

#include <linux/rculist_nulls.h>

#include <uapi/linux/btf.h>

#include "percpu_freelist.h"

#include "bpf_lru_list.h"

#include "map_in_map.h"
@@ -1162,6 +1164,44 @@ static void htab_map_free(struct bpf_map *map) 
	kfree(htab);

}



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

				   struct seq_file *m)

{

	void *value;



	rcu_read_lock();



	value = htab_map_lookup_elem(map, key);

	if (!value) {

		rcu_read_unlock();

		return;

	}



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

	seq_puts(m, ": ");

	btf_type_seq_show(map->btf, map->btf_value_type_id, value, m);

	seq_puts(m, "\n");



	rcu_read_unlock();

}



static int htab_map_check_btf(const struct bpf_map *map, const struct btf *btf,

			      u32 btf_key_id, u32 btf_value_id)

{

	const struct btf_type *key_type, *value_type;

	u32 key_size, value_size;



	key_type = btf_type_id_size(btf, &btf_key_id, &key_size);

	if (!key_type || key_size != map->key_size)

		return -EINVAL;



	value_type = btf_type_id_size(btf, &btf_value_id, &value_size);

	if (!value_type || value_size != map->value_size)

		return -EINVAL;



	return 0;

}



const struct bpf_map_ops htab_map_ops = {

	.map_alloc_check = htab_map_alloc_check,

	.map_alloc = htab_map_alloc,
@@ -1171,6 +1211,8 @@ const struct bpf_map_ops htab_map_ops = { 
	.map_update_elem = htab_map_update_elem,

	.map_delete_elem = htab_map_delete_elem,

	.map_gen_lookup = htab_map_gen_lookup,

	.map_seq_show_elem = htab_map_seq_show_elem,

	.map_check_btf = htab_map_check_btf,

};



const struct bpf_map_ops htab_lru_map_ops = {
@@ -1182,6 +1224,8 @@ const struct bpf_map_ops htab_lru_map_ops = { 
	.map_update_elem = htab_lru_map_update_elem,

	.map_delete_elem = htab_lru_map_delete_elem,

	.map_gen_lookup = htab_lru_map_gen_lookup,

	.map_seq_show_elem = htab_map_seq_show_elem,

	.map_check_btf = htab_map_check_btf,

};



/* Called from eBPF program */

kernel/bpf/inode.c

+5 −3
Original line number Diff line number Diff line
@@ -196,19 +196,21 @@ static void *map_seq_next(struct seq_file *m, void *v, loff_t *pos) 
{

	struct bpf_map *map = seq_file_to_map(m);

	void *key = map_iter(m)->key;

	void *prev_key;



	if (map_iter(m)->done)

		return NULL;



	if (unlikely(v == SEQ_START_TOKEN))

		goto done;

		prev_key = NULL;

	else

		prev_key = key;



	if (map->ops->map_get_next_key(map, key, key)) {

	if (map->ops->map_get_next_key(map, prev_key, key)) {

		map_iter(m)->done = true;

		return NULL;

	}



done:

	++(*pos);

	return key;

}

tools/testing/selftests/bpf/test_btf.c

+72 −15
Original line number Diff line number Diff line
@@ -131,6 +131,8 @@ struct btf_raw_test { 
	__u32 max_entries;

	bool btf_load_err;

	bool map_create_err;

	bool ordered_map;

	bool lossless_map;

	int hdr_len_delta;

	int type_off_delta;

	int str_off_delta;
@@ -2093,8 +2095,7 @@ struct pprint_mapv { 
	} aenum;

};



static struct btf_raw_test pprint_test = {

	.descr = "BTF pretty print test #1",

static struct btf_raw_test pprint_test_template = {

	.raw_types = {

		/* unsighed char */			/* [1] */

		BTF_TYPE_INT_ENC(NAME_TBD, 0, 0, 8, 1),
@@ -2146,8 +2147,6 @@ static struct btf_raw_test pprint_test = { 
	},

	.str_sec = "\0unsigned char\0unsigned short\0unsigned int\0int\0unsigned long long\0uint8_t\0uint16_t\0uint32_t\0int32_t\0uint64_t\0ui64\0ui8a\0ENUM_ZERO\0ENUM_ONE\0ENUM_TWO\0ENUM_THREE\0pprint_mapv\0ui32\0ui16\0si32\0unused_bits2a\0bits28\0unused_bits2b\0aenum",

	.str_sec_size = sizeof("\0unsigned char\0unsigned short\0unsigned int\0int\0unsigned long long\0uint8_t\0uint16_t\0uint32_t\0int32_t\0uint64_t\0ui64\0ui8a\0ENUM_ZERO\0ENUM_ONE\0ENUM_TWO\0ENUM_THREE\0pprint_mapv\0ui32\0ui16\0si32\0unused_bits2a\0bits28\0unused_bits2b\0aenum"),

	.map_type = BPF_MAP_TYPE_ARRAY,

	.map_name = "pprint_test",

	.key_size = sizeof(unsigned int),

	.value_size = sizeof(struct pprint_mapv),

	.key_type_id = 3,	/* unsigned int */
@@ -2155,6 +2154,40 @@ static struct btf_raw_test pprint_test = { 
	.max_entries = 128 * 1024,

};



static struct btf_pprint_test_meta {

	const char *descr;

	enum bpf_map_type map_type;

	const char *map_name;

	bool ordered_map;

	bool lossless_map;

} pprint_tests_meta[] = {

{

	.descr = "BTF pretty print array",

	.map_type = BPF_MAP_TYPE_ARRAY,

	.map_name = "pprint_test_array",

	.ordered_map = true,

	.lossless_map = true,

},



{

	.descr = "BTF pretty print hash",

	.map_type = BPF_MAP_TYPE_HASH,

	.map_name = "pprint_test_hash",

	.ordered_map = false,

	.lossless_map = true,

},



{

	.descr = "BTF pretty print lru hash",

	.map_type = BPF_MAP_TYPE_LRU_HASH,

	.map_name = "pprint_test_lru_hash",

	.ordered_map = false,

	.lossless_map = false,

},



};





static void set_pprint_mapv(struct pprint_mapv *v, uint32_t i)

{

	v->ui32 = i;
@@ -2166,10 +2199,12 @@ static void set_pprint_mapv(struct pprint_mapv *v, uint32_t i) 
	v->aenum = i & 0x03;

}



static int test_pprint(void)

static int do_test_pprint(void)

{

	const struct btf_raw_test *test = &pprint_test;

	const struct btf_raw_test *test = &pprint_test_template;

	struct bpf_create_map_attr create_attr = {};

	unsigned int key, nr_read_elems;

	bool ordered_map, lossless_map;

	int map_fd = -1, btf_fd = -1;

	struct pprint_mapv mapv = {};

	unsigned int raw_btf_size;
@@ -2178,7 +2213,6 @@ static int test_pprint(void) 
	char pin_path[255];

	size_t line_len = 0;

	char *line = NULL;

	unsigned int key;

	uint8_t *raw_btf;

	ssize_t nread;

	int err, ret;
@@ -2251,14 +2285,18 @@ static int test_pprint(void) 
		goto done;

	}



	key = 0;

	nr_read_elems = 0;

	ordered_map = test->ordered_map;

	lossless_map = test->lossless_map;

	do {

		ssize_t nexpected_line;

		unsigned int next_key;



		set_pprint_mapv(&mapv, key);

		next_key = ordered_map ? nr_read_elems : atoi(line);

		set_pprint_mapv(&mapv, next_key);

		nexpected_line = snprintf(expected_line, sizeof(expected_line),

					  "%u: {%u,0,%d,0x%x,0x%x,0x%x,{%lu|[%u,%u,%u,%u,%u,%u,%u,%u]},%s}\n",

					  key,

					  next_key,

					  mapv.ui32, mapv.si32,

					  mapv.unused_bits2a, mapv.bits28, mapv.unused_bits2b,

					  mapv.ui64,
@@ -2281,11 +2319,12 @@ static int test_pprint(void) 
		}



		nread = getline(&line, &line_len, pin_file);

	} while (++key < test->max_entries && nread > 0);

	} while (++nr_read_elems < test->max_entries && nread > 0);



	if (CHECK(key < test->max_entries,

		  "Unexpected EOF. key:%u test->max_entries:%u",

		  key, test->max_entries)) {

	if (lossless_map &&

	    CHECK(nr_read_elems < test->max_entries,

		  "Unexpected EOF. nr_read_elems:%u test->max_entries:%u",

		  nr_read_elems, test->max_entries)) {

		err = -1;

		goto done;

	}
@@ -2314,6 +2353,24 @@ done: 
	return err;

}



static int test_pprint(void)

{

	unsigned int i;

	int err = 0;



	for (i = 0; i < ARRAY_SIZE(pprint_tests_meta); i++) {

		pprint_test_template.descr = pprint_tests_meta[i].descr;

		pprint_test_template.map_type = pprint_tests_meta[i].map_type;

		pprint_test_template.map_name = pprint_tests_meta[i].map_name;

		pprint_test_template.ordered_map = pprint_tests_meta[i].ordered_map;

		pprint_test_template.lossless_map = pprint_tests_meta[i].lossless_map;



		err |= count_result(do_test_pprint());

	}



	return err;

}



static void usage(const char *cmd)

{

	fprintf(stderr, "Usage: %s [-l] [[-r test_num (1 - %zu)] | [-g test_num (1 - %zu)] | [-f test_num (1 - %zu)] | [-p]]\n",
@@ -2409,7 +2466,7 @@ int main(int argc, char **argv) 
		err |= test_file();



	if (args.pprint_test)

		err |= count_result(test_pprint());

		err |= test_pprint();



	if (args.raw_test || args.get_info_test || args.file_test ||

	    args.pprint_test)

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