From: Yonghong Song yhs@fb.com
mainline inclusion from mainline-v4.20-rc1 commit c7b27c37af3da5a63f32b0bc99569e3069e4d9c1 category: feature bugzilla: 43460 CVE: NA
--------------------------------------- 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: Yonghong Song yhs@fb.com Signed-off-by: Daniel Borkmann daniel@iogearbox.net Signed-off-by: liuxin liuxin264@huawei.com Reviewed-by: Cheng Jian cj.chengjian@huawei.com Signed-off-by: Yang Yingliang yangyingliang@huawei.com --- kernel/bpf/arraymap.c | 24 ++++++++++++++++++++++++ kernel/bpf/hashtab.c | 31 +++++++++++++++++++++++++++++++ 2 files changed, 55 insertions(+)
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 3f3ed33bd2fd..5268e3de1bd7 100644 --- a/kernel/bpf/hashtab.c +++ b/kernel/bpf/hashtab.c @@ -1296,6 +1296,35 @@ 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, @@ -1304,6 +1333,7 @@ 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 = { @@ -1314,6 +1344,7 @@ 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)