bpf: Rename bpf_reg_state variables

Using "reg" for an array of bpf_reg_state and "reg[i + 1]" for an
individual bpf_reg_state is error-prone and verbose. Use "regs" for the
former and "reg" for the latter as other code nearby does.

Signed-off-by: Dmitrii Banshchikov <me@ubique.spb.ru>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20210212205642.620788-2-me@ubique.spb.ru

diff --git a/kernel/bpf/btf.c b/kernel/bpf/btf.c
index 756a93f..bd5d2c5 100644 (file)
--- a/kernel/bpf/btf.c
+++ b/kernel/bpf/btf.c
@@ -5291,7 +5291,7 @@ int btf_check_type_match(struct bpf_verifier_log *log, const struct bpf_prog *pr
  * Only PTR_TO_CTX and SCALAR_VALUE states are recognized.
  */
 int btf_check_func_arg_match(struct bpf_verifier_env *env, int subprog,
-                            struct bpf_reg_state *reg)
+                            struct bpf_reg_state *regs)
 {
        struct bpf_verifier_log *log = &env->log;
        struct bpf_prog *prog = env->prog;
@@ -5337,17 +5337,19 @@ int btf_check_func_arg_match(struct bpf_verifier_env *env, int subprog,
         * verifier sees.
         */
        for (i = 0; i < nargs; i++) {
+               struct bpf_reg_state *reg = &regs[i + 1];
+
                t = btf_type_by_id(btf, args[i].type);
                while (btf_type_is_modifier(t))
                        t = btf_type_by_id(btf, t->type);
                if (btf_type_is_int(t) || btf_type_is_enum(t)) {
-                       if (reg[i + 1].type == SCALAR_VALUE)
+                       if (reg->type == SCALAR_VALUE)
                                continue;
                        bpf_log(log, "R%d is not a scalar\n", i + 1);
                        goto out;
                }
                if (btf_type_is_ptr(t)) {
-                       if (reg[i + 1].type == SCALAR_VALUE) {
+                       if (reg->type == SCALAR_VALUE) {
                                bpf_log(log, "R%d is not a pointer\n", i + 1);
                                goto out;
                        }
@@ -5355,13 +5357,13 @@ int btf_check_func_arg_match(struct bpf_verifier_env *env, int subprog,
                         * is passing PTR_TO_CTX.
                         */
                        if (btf_get_prog_ctx_type(log, btf, t, prog->type, i)) {
-                               if (reg[i + 1].type != PTR_TO_CTX) {
+                               if (reg->type != PTR_TO_CTX) {
                                        bpf_log(log,
                                                "arg#%d expected pointer to ctx, but got %s\n",
                                                i, btf_kind_str[BTF_INFO_KIND(t->info)]);
                                        goto out;
                                }
-                               if (check_ctx_reg(env, &reg[i + 1], i + 1))
+                               if (check_ctx_reg(env, reg, i + 1))
                                        goto out;
                                continue;
                        }
@@ -5388,7 +5390,7 @@ out:
  * (either PTR_TO_CTX or SCALAR_VALUE).
  */
 int btf_prepare_func_args(struct bpf_verifier_env *env, int subprog,
-                         struct bpf_reg_state *reg)
+                         struct bpf_reg_state *regs)
 {
        struct bpf_verifier_log *log = &env->log;
        struct bpf_prog *prog = env->prog;
@@ -5459,16 +5461,18 @@ int btf_prepare_func_args(struct bpf_verifier_env *env, int subprog,
         * Only PTR_TO_CTX and SCALAR are supported atm.
         */
        for (i = 0; i < nargs; i++) {
+               struct bpf_reg_state *reg = &regs[i + 1];
+
                t = btf_type_by_id(btf, args[i].type);
                while (btf_type_is_modifier(t))
                        t = btf_type_by_id(btf, t->type);
                if (btf_type_is_int(t) || btf_type_is_enum(t)) {
-                       reg[i + 1].type = SCALAR_VALUE;
+                       reg->type = SCALAR_VALUE;
                        continue;
                }
                if (btf_type_is_ptr(t) &&
                    btf_get_prog_ctx_type(log, btf, t, prog_type, i)) {
-                       reg[i + 1].type = PTR_TO_CTX;
+                       reg->type = PTR_TO_CTX;
                        continue;
                }
                bpf_log(log, "Arg#%d type %s in %s() is not supported yet.\n",