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| author |   Andrii Nakryiko <andrii@kernel.org> | 2022-07-14 22:31:44 -0700 |
|---|---|---|
| committer |   Alexei Starovoitov <ast@kernel.org> | 2022-07-19 09:45:34 -0700 |
| commit | d937bc3449fa868cbeaf5c87576f9929b765c1e0 (patch) | |
| tree | 8ff4872e0ead2666177b162d0320e2bf959f0e93 /kernel/bpf/arraymap.c | |
| parent | bpf: fix potential 32-bit overflow when accessing ARRAY map element (diff) | |
| download | linux-dev-d937bc3449fa868cbeaf5c87576f9929b765c1e0.tar.xz linux-dev-d937bc3449fa868cbeaf5c87576f9929b765c1e0.zip | |
bpf: make uniform use of array->elem_size everywhere in arraymap.c
BPF_MAP_TYPE_ARRAY is rounding value_size to closest multiple of 8 and
stores that as array->elem_size for various memory allocations and
accesses.
But the code tends to re-calculate round_up(map->value_size, 8) in
multiple places instead of using array->elem_size. Cleaning this up and
making sure we always use array->size to avoid duplication of this
(admittedly simple) logic for consistency.
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/r/20220715053146.1291891-3-andrii@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Diffstat (limited to 'kernel/bpf/arraymap.c')
| -rw-r--r-- | kernel/bpf/arraymap.c | 14 |
1 files changed, 8 insertions, 6 deletions
diff --git a/kernel/bpf/arraymap.c b/kernel/bpf/arraymap.c index 1d05d63e6fa5..98ee09155151 100644 --- a/kernel/bpf/arraymap.c +++ b/kernel/bpf/arraymap.c @@ -208,7 +208,7 @@ static int array_map_gen_lookup(struct bpf_map *map, struct bpf_insn *insn_buf) { struct bpf_array *array = container_of(map, struct bpf_array, map); struct bpf_insn *insn = insn_buf; - u32 elem_size = round_up(map->value_size, 8); + u32 elem_size = array->elem_size; const int ret = BPF_REG_0; const int map_ptr = BPF_REG_1; const int index = BPF_REG_2; @@ -277,7 +277,7 @@ int bpf_percpu_array_copy(struct bpf_map *map, void *key, void *value) * access 'value_size' of them, so copying rounded areas * will not leak any kernel data */ - size = round_up(map->value_size, 8); + size = array->elem_size; rcu_read_lock(); pptr = array->pptrs[index & array->index_mask]; for_each_possible_cpu(cpu) { @@ -381,7 +381,7 @@ int bpf_percpu_array_update(struct bpf_map *map, void *key, void *value, * returned or zeros which were zero-filled by percpu_alloc, * so no kernel data leaks possible */ - size = round_up(map->value_size, 8); + size = array->elem_size; rcu_read_lock(); pptr = array->pptrs[index & array->index_mask]; for_each_possible_cpu(cpu) { @@ -587,6 +587,7 @@ static int __bpf_array_map_seq_show(struct seq_file *seq, void *v) struct bpf_iter_seq_array_map_info *info = seq->private; struct bpf_iter__bpf_map_elem ctx = {}; struct bpf_map *map = info->map; + struct bpf_array *array = container_of(map, struct bpf_array, map); struct bpf_iter_meta meta; struct bpf_prog *prog; int off = 0, cpu = 0; @@ -607,7 +608,7 @@ static int __bpf_array_map_seq_show(struct seq_file *seq, void *v) ctx.value = v; } else { pptr = v; - size = round_up(map->value_size, 8); + size = array->elem_size; for_each_possible_cpu(cpu) { bpf_long_memcpy(info->percpu_value_buf + off, per_cpu_ptr(pptr, cpu), @@ -637,11 +638,12 @@ static int bpf_iter_init_array_map(void *priv_data, { struct bpf_iter_seq_array_map_info *seq_info = priv_data; struct bpf_map *map = aux->map; + struct bpf_array *array = container_of(map, struct bpf_array, map); void *value_buf; u32 buf_size; if (map->map_type == BPF_MAP_TYPE_PERCPU_ARRAY) { - buf_size = round_up(map->value_size, 8) * num_possible_cpus(); + buf_size = array->elem_size * num_possible_cpus(); value_buf = kmalloc(buf_size, GFP_USER | __GFP_NOWARN); if (!value_buf) return -ENOMEM; @@ -1326,7 +1328,7 @@ static int array_of_map_gen_lookup(struct bpf_map *map, struct bpf_insn *insn_buf) { struct bpf_array *array = container_of(map, struct bpf_array, map); - u32 elem_size = round_up(map->value_size, 8); + u32 elem_size = array->elem_size; struct bpf_insn *insn = insn_buf; const int ret = BPF_REG_0; const int map_ptr = BPF_REG_1; |