bpf: extract register state printing

Extract printing register state representation logic into a separate
helper, as we are going to reuse it for spilled register state printing
in the next patch. This also nicely reduces code nestedness.

No functional changes.

Acked-by: Eduard Zingerman <eddyz87@gmail.com>
Acked-by: Stanislav Fomichev <sdf@google.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/r/20231118034623.3320920-4-andrii@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>

diff --git a/kernel/bpf/log.c b/kernel/bpf/log.c
index c1b257eac21b76042008b41f825403b17a8b4d8e..05d737e2fab3af53a8ae8942fea7ea66b9f6e150 100644 (file)
--- a/kernel/bpf/log.c
+++ b/kernel/bpf/log.c
@@ -553,6 +553,67 @@ static void print_scalar_ranges(struct bpf_verifier_env *env,
        }
 }
 
+static void print_reg_state(struct bpf_verifier_env *env, const struct bpf_reg_state *reg)
+{
+       enum bpf_reg_type t;
+       const char *sep = "";
+
+       t = reg->type;
+       if (t == SCALAR_VALUE && reg->precise)
+               verbose(env, "P");
+       if ((t == SCALAR_VALUE || t == PTR_TO_STACK) &&
+           tnum_is_const(reg->var_off)) {
+               /* reg->off should be 0 for SCALAR_VALUE */
+               verbose(env, "%s", t == SCALAR_VALUE ? "" : reg_type_str(env, t));
+               verbose(env, "%lld", reg->var_off.value + reg->off);
+               return;
+       }
+/*
+ * _a stands for append, was shortened to avoid multiline statements below.
+ * This macro is used to output a comma separated list of attributes.
+ */
+#define verbose_a(fmt, ...) ({ verbose(env, "%s" fmt, sep, __VA_ARGS__); sep = ","; })
+
+       verbose(env, "%s", reg_type_str(env, t));
+       if (base_type(t) == PTR_TO_BTF_ID)
+               verbose(env, "%s", btf_type_name(reg->btf, reg->btf_id));
+       verbose(env, "(");
+       if (reg->id)
+               verbose_a("id=%d", reg->id);
+       if (reg->ref_obj_id)
+               verbose_a("ref_obj_id=%d", reg->ref_obj_id);
+       if (type_is_non_owning_ref(reg->type))
+               verbose_a("%s", "non_own_ref");
+       if (t != SCALAR_VALUE)
+               verbose_a("off=%d", reg->off);
+       if (type_is_pkt_pointer(t))
+               verbose_a("r=%d", reg->range);
+       else if (base_type(t) == CONST_PTR_TO_MAP ||
+                base_type(t) == PTR_TO_MAP_KEY ||
+                base_type(t) == PTR_TO_MAP_VALUE)
+               verbose_a("ks=%d,vs=%d",
+                         reg->map_ptr->key_size,
+                         reg->map_ptr->value_size);
+       if (tnum_is_const(reg->var_off)) {
+               /* Typically an immediate SCALAR_VALUE, but
+                * could be a pointer whose offset is too big
+                * for reg->off
+                */
+               verbose_a("imm=%llx", reg->var_off.value);
+       } else {
+               print_scalar_ranges(env, reg, &sep);
+               if (!tnum_is_unknown(reg->var_off)) {
+                       char tn_buf[48];
+
+                       tnum_strn(tn_buf, sizeof(tn_buf), reg->var_off);
+                       verbose_a("var_off=%s", tn_buf);
+               }
+       }
+       verbose(env, ")");
+
+#undef verbose_a
+}
+
 void print_verifier_state(struct bpf_verifier_env *env, const struct bpf_func_state *state,
                          bool print_all)
 {
@@ -564,69 +625,14 @@ void print_verifier_state(struct bpf_verifier_env *env, const struct bpf_func_st
                verbose(env, " frame%d:", state->frameno);
        for (i = 0; i < MAX_BPF_REG; i++) {
                reg = &state->regs[i];
-               t = reg->type;
-               if (t == NOT_INIT)
+               if (reg->type == NOT_INIT)
                        continue;
                if (!print_all && !reg_scratched(env, i))
                        continue;
                verbose(env, " R%d", i);
                print_liveness(env, reg->live);
                verbose(env, "=");
-               if (t == SCALAR_VALUE && reg->precise)
-                       verbose(env, "P");
-               if ((t == SCALAR_VALUE || t == PTR_TO_STACK) &&
-                   tnum_is_const(reg->var_off)) {
-                       /* reg->off should be 0 for SCALAR_VALUE */
-                       verbose(env, "%s", t == SCALAR_VALUE ? "" : reg_type_str(env, t));
-                       verbose(env, "%lld", reg->var_off.value + reg->off);
-               } else {
-                       const char *sep = "";
-
-                       verbose(env, "%s", reg_type_str(env, t));
-                       if (base_type(t) == PTR_TO_BTF_ID)
-                               verbose(env, "%s", btf_type_name(reg->btf, reg->btf_id));
-                       verbose(env, "(");
-/*
- * _a stands for append, was shortened to avoid multiline statements below.
- * This macro is used to output a comma separated list of attributes.
- */
-#define verbose_a(fmt, ...) ({ verbose(env, "%s" fmt, sep, __VA_ARGS__); sep = ","; })
-
-                       if (reg->id)
-                               verbose_a("id=%d", reg->id);
-                       if (reg->ref_obj_id)
-                               verbose_a("ref_obj_id=%d", reg->ref_obj_id);
-                       if (type_is_non_owning_ref(reg->type))
-                               verbose_a("%s", "non_own_ref");
-                       if (t != SCALAR_VALUE)
-                               verbose_a("off=%d", reg->off);
-                       if (type_is_pkt_pointer(t))
-                               verbose_a("r=%d", reg->range);
-                       else if (base_type(t) == CONST_PTR_TO_MAP ||
-                                base_type(t) == PTR_TO_MAP_KEY ||
-                                base_type(t) == PTR_TO_MAP_VALUE)
-                               verbose_a("ks=%d,vs=%d",
-                                         reg->map_ptr->key_size,
-                                         reg->map_ptr->value_size);
-                       if (tnum_is_const(reg->var_off)) {
-                               /* Typically an immediate SCALAR_VALUE, but
-                                * could be a pointer whose offset is too big
-                                * for reg->off
-                                */
-                               verbose_a("imm=%llx", reg->var_off.value);
-                       } else {
-                               print_scalar_ranges(env, reg, &sep);
-                               if (!tnum_is_unknown(reg->var_off)) {
-                                       char tn_buf[48];
-
-                                       tnum_strn(tn_buf, sizeof(tn_buf), reg->var_off);
-                                       verbose_a("var_off=%s", tn_buf);
-                               }
-                       }
-#undef verbose_a
-
-                       verbose(env, ")");
-               }
+               print_reg_state(env, reg);
        }
        for (i = 0; i < state->allocated_stack / BPF_REG_SIZE; i++) {
                char types_buf[BPF_REG_SIZE + 1];