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authorDaniel Borkmann <daniel@iogearbox.net>2018-08-30 14:03:54 +0200
committerDaniel Borkmann <daniel@iogearbox.net>2018-08-30 14:03:55 +0200
commit56b48c6a6008d9d5d023b7dd002913c8715dc3a0 (patch)
tree768a6dc2c2ed7b998cb2bb0ed3d1ecfbf055a26b
parent234dbe3dc1db002076bb593c1f6dc5f3ebc46b21 (diff)
parent1a86ad89da1c06b2a326953309dcb99f0d079a32 (diff)
downloadmachiattobin-xdp-56b48c6a6008d9d5d023b7dd002913c8715dc3a0.tar.gz
Merge branch 'bpf-bpffs-bpftool-dump-with-btf'
Yonghong Song says: ==================== Commit a26ca7c982cb ("bpf: btf: Add pretty print support to the basic arraymap") and Commit 699c86d6ec21 ("bpf: btf: add pretty print for hash/lru_hash maps") added bpffs pretty print for array, hash and lru hash maps. The pretty print gives users a structurally formatted dump for keys/values which much easy to understand than raw bytes. This patch set implemented bpffs pretty print support for percpu arraymap, percpu hashmap and percpu lru hashmap. For complex key/value types, the pretty print here is even more useful due to: . large volumne of data making it even harder to correlate bytes to a particular field in a particular cpu. . kernel rounds the value size for each cpu to multiple of 8. User has to be aware of this otherwise wrong value may be derived from cpu 1/2/... For example, we may have a bpffs pretty print like below: 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} } for a percpu map. This patch also added percpu formatted print on bpftool. For example, bpftool may print like below: { "key": 0, "values": [{ "cpu": 0, "value": { "ui32": 0, "ui16": 0, } },{ "cpu": 1, "value": { "ui32": 1, "ui16": 0, } },{ "cpu": 2, "value": { "ui32": 2, "ui16": 0, } },{ "cpu": 3, "value": { "ui32": 3, "ui16": 0, } } ] } Patch #1 implemented bpffs pretty print for percpu arraymap/hash/lru_hash in kernel. Patch #2 added the test case in tools bpf selftest test_btf. Patch #3 added percpu map btf based dump. ==================== Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
-rw-r--r--kernel/bpf/arraymap.c24
-rw-r--r--kernel/bpf/hashtab.c31
-rw-r--r--tools/bpf/bpftool/map.c33
-rw-r--r--tools/testing/selftests/bpf/test_btf.c179
4 files changed, 230 insertions, 37 deletions
diff --git a/kernel/bpf/arraymap.c b/kernel/bpf/arraymap.c
index 0c17aab3ce5f..f9d24121be99 100644
--- a/kernel/bpf/arraymap.c
+++ b/kernel/bpf/arraymap.c
@@ -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,
};
diff --git a/kernel/bpf/hashtab.c b/kernel/bpf/hashtab.c
index 03cc59ee9c95..2c1790288138 100644
--- a/kernel/bpf/hashtab.c
+++ b/kernel/bpf/hashtab.c
@@ -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)
diff --git a/tools/bpf/bpftool/map.c b/tools/bpf/bpftool/map.c
index b2ec20e562bd..df175bc33c5d 100644
--- a/tools/bpf/bpftool/map.c
+++ b/tools/bpf/bpftool/map.c
@@ -169,9 +169,28 @@ static int do_dump_btf(const struct btf_dumper *d,
if (ret)
goto err_end_obj;
- jsonw_name(d->jw, "value");
+ if (!map_is_per_cpu(map_info->type)) {
+ jsonw_name(d->jw, "value");
+ ret = btf_dumper_type(d, map_info->btf_value_type_id, value);
+ } else {
+ unsigned int i, n, step;
- ret = btf_dumper_type(d, map_info->btf_value_type_id, value);
+ jsonw_name(d->jw, "values");
+ jsonw_start_array(d->jw);
+ n = get_possible_cpus();
+ step = round_up(map_info->value_size, 8);
+ for (i = 0; i < n; i++) {
+ jsonw_start_object(d->jw);
+ jsonw_int_field(d->jw, "cpu", i);
+ jsonw_name(d->jw, "value");
+ ret = btf_dumper_type(d, map_info->btf_value_type_id,
+ value + i * step);
+ jsonw_end_object(d->jw);
+ if (ret)
+ break;
+ }
+ jsonw_end_array(d->jw);
+ }
err_end_obj:
/* end of key-value pair */
@@ -298,6 +317,16 @@ static void print_entry_json(struct bpf_map_info *info, unsigned char *key,
jsonw_end_object(json_wtr);
}
jsonw_end_array(json_wtr);
+ if (btf) {
+ struct btf_dumper d = {
+ .btf = btf,
+ .jw = json_wtr,
+ .is_plain_text = false,
+ };
+
+ jsonw_name(json_wtr, "formatted");
+ do_dump_btf(&d, info, key, value);
+ }
}
jsonw_end_object(json_wtr);
diff --git a/tools/testing/selftests/bpf/test_btf.c b/tools/testing/selftests/bpf/test_btf.c
index 6b5cfeb7a9cc..f42b3396d622 100644
--- a/tools/testing/selftests/bpf/test_btf.c
+++ b/tools/testing/selftests/bpf/test_btf.c
@@ -4,6 +4,7 @@
#include <linux/bpf.h>
#include <linux/btf.h>
#include <linux/err.h>
+#include <linux/kernel.h>
#include <bpf/bpf.h>
#include <sys/resource.h>
#include <libelf.h>
@@ -45,7 +46,6 @@ static int count_result(int err)
return err;
}
-#define min(a, b) ((a) < (b) ? (a) : (b))
#define __printf(a, b) __attribute__((format(printf, a, b)))
__printf(1, 2)
@@ -130,6 +130,7 @@ struct btf_raw_test {
bool map_create_err;
bool ordered_map;
bool lossless_map;
+ bool percpu_map;
int hdr_len_delta;
int type_off_delta;
int str_off_delta;
@@ -2157,6 +2158,7 @@ static struct btf_pprint_test_meta {
const char *map_name;
bool ordered_map;
bool lossless_map;
+ bool percpu_map;
} pprint_tests_meta[] = {
{
.descr = "BTF pretty print array",
@@ -2164,6 +2166,7 @@ static struct btf_pprint_test_meta {
.map_name = "pprint_test_array",
.ordered_map = true,
.lossless_map = true,
+ .percpu_map = false,
},
{
@@ -2172,6 +2175,7 @@ static struct btf_pprint_test_meta {
.map_name = "pprint_test_hash",
.ordered_map = false,
.lossless_map = true,
+ .percpu_map = false,
},
{
@@ -2180,30 +2184,83 @@ static struct btf_pprint_test_meta {
.map_name = "pprint_test_lru_hash",
.ordered_map = false,
.lossless_map = false,
+ .percpu_map = false,
+},
+
+{
+ .descr = "BTF pretty print percpu array",
+ .map_type = BPF_MAP_TYPE_PERCPU_ARRAY,
+ .map_name = "pprint_test_percpu_array",
+ .ordered_map = true,
+ .lossless_map = true,
+ .percpu_map = true,
+},
+
+{
+ .descr = "BTF pretty print percpu hash",
+ .map_type = BPF_MAP_TYPE_PERCPU_HASH,
+ .map_name = "pprint_test_percpu_hash",
+ .ordered_map = false,
+ .lossless_map = true,
+ .percpu_map = true,
+},
+
+{
+ .descr = "BTF pretty print lru percpu hash",
+ .map_type = BPF_MAP_TYPE_LRU_PERCPU_HASH,
+ .map_name = "pprint_test_lru_percpu_hash",
+ .ordered_map = false,
+ .lossless_map = false,
+ .percpu_map = true,
},
};
-static void set_pprint_mapv(struct pprint_mapv *v, uint32_t i)
+static void set_pprint_mapv(struct pprint_mapv *v, uint32_t i,
+ int num_cpus, int rounded_value_size)
{
- v->ui32 = i;
- v->si32 = -i;
- v->unused_bits2a = 3;
- v->bits28 = i;
- v->unused_bits2b = 3;
- v->ui64 = i;
- v->aenum = i & 0x03;
+ int cpu;
+
+ for (cpu = 0; cpu < num_cpus; cpu++) {
+ v->ui32 = i + cpu;
+ v->si32 = -i;
+ v->unused_bits2a = 3;
+ v->bits28 = i;
+ v->unused_bits2b = 3;
+ v->ui64 = i;
+ v->aenum = i & 0x03;
+ v = (void *)v + rounded_value_size;
+ }
}
+static int check_line(const char *expected_line, int nexpected_line,
+ int expected_line_len, const char *line)
+{
+ if (CHECK(nexpected_line == expected_line_len,
+ "expected_line is too long"))
+ return -1;
+
+ if (strcmp(expected_line, line)) {
+ fprintf(stderr, "unexpected pprint output\n");
+ fprintf(stderr, "expected: %s", expected_line);
+ fprintf(stderr, " read: %s", line);
+ return -1;
+ }
+
+ return 0;
+}
+
+
static int do_test_pprint(void)
{
const struct btf_raw_test *test = &pprint_test_template;
struct bpf_create_map_attr create_attr = {};
+ bool ordered_map, lossless_map, percpu_map;
+ int err, ret, num_cpus, rounded_value_size;
+ struct pprint_mapv *mapv = NULL;
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;
char expected_line[255];
FILE *pin_file = NULL;
@@ -2212,7 +2269,6 @@ static int do_test_pprint(void)
char *line = NULL;
uint8_t *raw_btf;
ssize_t nread;
- int err, ret;
fprintf(stderr, "%s......", test->descr);
raw_btf = btf_raw_create(&hdr_tmpl, test->raw_types,
@@ -2261,9 +2317,18 @@ static int do_test_pprint(void)
if (CHECK(err, "bpf_obj_pin(%s): errno:%d.", pin_path, errno))
goto done;
+ percpu_map = test->percpu_map;
+ num_cpus = percpu_map ? bpf_num_possible_cpus() : 1;
+ rounded_value_size = round_up(sizeof(struct pprint_mapv), 8);
+ mapv = calloc(num_cpus, rounded_value_size);
+ if (CHECK(!mapv, "mapv allocation failure")) {
+ err = -1;
+ goto done;
+ }
+
for (key = 0; key < test->max_entries; key++) {
- set_pprint_mapv(&mapv, key);
- bpf_map_update_elem(map_fd, &key, &mapv, 0);
+ set_pprint_mapv(mapv, key, num_cpus, rounded_value_size);
+ bpf_map_update_elem(map_fd, &key, mapv, 0);
}
pin_file = fopen(pin_path, "r");
@@ -2286,33 +2351,74 @@ static int do_test_pprint(void)
ordered_map = test->ordered_map;
lossless_map = test->lossless_map;
do {
+ struct pprint_mapv *cmapv;
ssize_t nexpected_line;
unsigned int next_key;
+ int cpu;
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",
- next_key,
- mapv.ui32, mapv.si32,
- mapv.unused_bits2a, mapv.bits28, mapv.unused_bits2b,
- mapv.ui64,
- mapv.ui8a[0], mapv.ui8a[1], mapv.ui8a[2], mapv.ui8a[3],
- mapv.ui8a[4], mapv.ui8a[5], mapv.ui8a[6], mapv.ui8a[7],
- pprint_enum_str[mapv.aenum]);
-
- if (CHECK(nexpected_line == sizeof(expected_line),
- "expected_line is too long")) {
- err = -1;
- goto done;
+ set_pprint_mapv(mapv, next_key, num_cpus, rounded_value_size);
+ cmapv = mapv;
+
+ for (cpu = 0; cpu < num_cpus; cpu++) {
+ if (percpu_map) {
+ /* for percpu map, the format looks like:
+ * <key>: {
+ * cpu0: <value_on_cpu0>
+ * cpu1: <value_on_cpu1>
+ * ...
+ * cpun: <value_on_cpun>
+ * }
+ *
+ * let us verify the line containing the key here.
+ */
+ if (cpu == 0) {
+ nexpected_line = snprintf(expected_line,
+ sizeof(expected_line),
+ "%u: {\n",
+ next_key);
+
+ err = check_line(expected_line, nexpected_line,
+ sizeof(expected_line), line);
+ if (err == -1)
+ goto done;
+ }
+
+ /* read value@cpu */
+ nread = getline(&line, &line_len, pin_file);
+ if (nread < 0)
+ break;
+ }
+
+ nexpected_line = snprintf(expected_line, sizeof(expected_line),
+ "%s%u: {%u,0,%d,0x%x,0x%x,0x%x,"
+ "{%lu|[%u,%u,%u,%u,%u,%u,%u,%u]},%s}\n",
+ percpu_map ? "\tcpu" : "",
+ percpu_map ? cpu : next_key,
+ cmapv->ui32, cmapv->si32,
+ cmapv->unused_bits2a,
+ cmapv->bits28,
+ cmapv->unused_bits2b,
+ cmapv->ui64,
+ cmapv->ui8a[0], cmapv->ui8a[1],
+ cmapv->ui8a[2], cmapv->ui8a[3],
+ cmapv->ui8a[4], cmapv->ui8a[5],
+ cmapv->ui8a[6], cmapv->ui8a[7],
+ pprint_enum_str[cmapv->aenum]);
+
+ err = check_line(expected_line, nexpected_line,
+ sizeof(expected_line), line);
+ if (err == -1)
+ goto done;
+
+ cmapv = (void *)cmapv + rounded_value_size;
}
- if (strcmp(expected_line, line)) {
- err = -1;
- fprintf(stderr, "unexpected pprint output\n");
- fprintf(stderr, "expected: %s", expected_line);
- fprintf(stderr, " read: %s", line);
- goto done;
+ if (percpu_map) {
+ /* skip the last bracket for the percpu map */
+ nread = getline(&line, &line_len, pin_file);
+ if (nread < 0)
+ break;
}
nread = getline(&line, &line_len, pin_file);
@@ -2334,6 +2440,8 @@ static int do_test_pprint(void)
err = 0;
done:
+ if (mapv)
+ free(mapv);
if (!err)
fprintf(stderr, "OK");
if (*btf_log_buf && (err || args.always_log))
@@ -2361,6 +2469,7 @@ static int test_pprint(void)
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;
+ pprint_test_template.percpu_map = pprint_tests_meta[i].percpu_map;
err |= count_result(do_test_pprint());
}