bpf: Add hashtab support for bpf_for_each_map_elem() helper
This patch added support for hashmap, percpu hashmap,
lru hashmap and percpu lru hashmap.
Signed-off-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20210226204927.3885020-1-yhs@fb.com
diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c
index 53afe94..9fe90ce5 100644
--- a/kernel/bpf/verifier.c
+++ b/kernel/bpf/verifier.c
@@ -5403,6 +5403,33 @@ static int __check_func_call(struct bpf_verifier_env *env, struct bpf_insn *insn
return 0;
}
+int map_set_for_each_callback_args(struct bpf_verifier_env *env,
+ struct bpf_func_state *caller,
+ struct bpf_func_state *callee)
+{
+ /* bpf_for_each_map_elem(struct bpf_map *map, void *callback_fn,
+ * void *callback_ctx, u64 flags);
+ * callback_fn(struct bpf_map *map, void *key, void *value,
+ * void *callback_ctx);
+ */
+ callee->regs[BPF_REG_1] = caller->regs[BPF_REG_1];
+
+ callee->regs[BPF_REG_2].type = PTR_TO_MAP_KEY;
+ __mark_reg_known_zero(&callee->regs[BPF_REG_2]);
+ callee->regs[BPF_REG_2].map_ptr = caller->regs[BPF_REG_1].map_ptr;
+
+ callee->regs[BPF_REG_3].type = PTR_TO_MAP_VALUE;
+ __mark_reg_known_zero(&callee->regs[BPF_REG_3]);
+ callee->regs[BPF_REG_3].map_ptr = caller->regs[BPF_REG_1].map_ptr;
+
+ /* pointer to stack or null */
+ callee->regs[BPF_REG_4] = caller->regs[BPF_REG_3];
+
+ /* unused */
+ __mark_reg_not_init(env, &callee->regs[BPF_REG_5]);
+ return 0;
+}
+
static int set_callee_state(struct bpf_verifier_env *env,
struct bpf_func_state *caller,
struct bpf_func_state *callee, int insn_idx)
