bpf: Refactor BPF_PSEUDO_CALL checking as a helper function

mainline inclusion
from mainline-5.12-rc1
commit 23a2d70c
category: feature
bugzilla: https://gitee.com/openeuler/kernel/issues/I5EUVD
CVE: NA

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=23a2d70c7a2f28eb1a8f6bc19d68d23968cad0ce

-------------------------------------------------

There is no functionality change. This refactoring intends
to facilitate next patch change with BPF_PSEUDO_FUNC.
Signed-off-by: NYonghong Song <yhs@fb.com>
Signed-off-by: NAlexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20210204234827.1628953-1-yhs@fb.com
(cherry picked from commit 23a2d70c)
Signed-off-by: NWang Yufen <wangyufen@huawei.com>

kernel/bpf/verifier.c

@@ -229,6 +229,12 @@ static void bpf_map_key_store(struct bpf_insn_aux_data *aux, u64 state)
 			     (poisoned ? BPF_MAP_KEY_POISON : 0ULL);
 }
 
+static bool bpf_pseudo_call(const struct bpf_insn *insn)
+{
+	return insn->code == (BPF_JMP | BPF_CALL) &&
+	       insn->src_reg == BPF_PSEUDO_CALL;
+}
+
 struct bpf_call_arg_meta {
 	struct bpf_map *map_ptr;
 	bool raw_mode;
@@ -1492,9 +1498,7 @@ static int check_subprogs(struct bpf_verifier_env *env)
 
 	/* determine subprog starts. The end is one before the next starts */
 	for (i = 0; i < insn_cnt; i++) {
-		if (insn[i].code != (BPF_JMP | BPF_CALL))
-			continue;
-		if (insn[i].src_reg != BPF_PSEUDO_CALL)
+		if (!bpf_pseudo_call(insn + i))
 			continue;
 		if (!env->bpf_capable) {
 			verbose(env,
@@ -3300,9 +3304,7 @@ static int check_max_stack_depth(struct bpf_verifier_env *env)
 continue_func:
 	subprog_end = subprog[idx + 1].start;
 	for (; i < subprog_end; i++) {
-		if (insn[i].code != (BPF_JMP | BPF_CALL))
-			continue;
-		if (insn[i].src_reg != BPF_PSEUDO_CALL)
+		if (!bpf_pseudo_call(insn + i))
 			continue;
 		/* remember insn and function to return to */
 		ret_insn[frame] = i + 1;
@@ -11301,8 +11303,7 @@ static int jit_subprogs(struct bpf_verifier_env *env)
 		return 0;
 
 	for (i = 0, insn = prog->insnsi; i < prog->len; i++, insn++) {
-		if (insn->code != (BPF_JMP | BPF_CALL) ||
-		    insn->src_reg != BPF_PSEUDO_CALL)
+		if (!bpf_pseudo_call(insn))
 			continue;
 		/* Upon error here we cannot fall back to interpreter but
 		 * need a hard reject of the program. Thus -EFAULT is
@@ -11405,8 +11406,7 @@ static int jit_subprogs(struct bpf_verifier_env *env)
 	for (i = 0; i < env->subprog_cnt; i++) {
 		insn = func[i]->insnsi;
 		for (j = 0; j < func[i]->len; j++, insn++) {
-			if (insn->code != (BPF_JMP | BPF_CALL) ||
-			    insn->src_reg != BPF_PSEUDO_CALL)
+			if (!bpf_pseudo_call(insn))
 				continue;
 			subprog = insn->off;
 			insn->imm = BPF_CAST_CALL(func[subprog]->bpf_func) -
@@ -11451,8 +11451,7 @@ static int jit_subprogs(struct bpf_verifier_env *env)
 	 * later look the same as if they were interpreted only.
 	 */
 	for (i = 0, insn = prog->insnsi; i < prog->len; i++, insn++) {
-		if (insn->code != (BPF_JMP | BPF_CALL) ||
-		    insn->src_reg != BPF_PSEUDO_CALL)
+		if (!bpf_pseudo_call(insn))
 			continue;
 		insn->off = env->insn_aux_data[i].call_imm;
 		subprog = find_subprog(env, i + insn->off + 1);
@@ -11489,8 +11488,7 @@ static int jit_subprogs(struct bpf_verifier_env *env)
 	/* cleanup main prog to be interpreted */
 	prog->jit_requested = 0;
 	for (i = 0, insn = prog->insnsi; i < prog->len; i++, insn++) {
-		if (insn->code != (BPF_JMP | BPF_CALL) ||
-		    insn->src_reg != BPF_PSEUDO_CALL)
+		if (!bpf_pseudo_call(insn))
 			continue;
 		insn->off = 0;
 		insn->imm = env->insn_aux_data[i].call_imm;
@@ -11525,8 +11523,7 @@ static int fixup_call_args(struct bpf_verifier_env *env)
 		return -EINVAL;
 	}
 	for (i = 0; i < prog->len; i++, insn++) {
-		if (insn->code != (BPF_JMP | BPF_CALL) ||
-		    insn->src_reg != BPF_PSEUDO_CALL)
+		if (!bpf_pseudo_call(insn))
 			continue;
 		depth = get_callee_stack_depth(env, insn, i);
 		if (depth < 0)