[PATCH bpf-next v3 07/15] bpf: Rename bpf_call_summary::num_params to arg_slot_cnt

[Yonghong Song <yonghong.song@linux.dev>]

The field 'num_params' counts the argument registers and outgoing
stack slots a helper or kfunc call takes. The next patch gives a
16-byte parameter two slots, so the name stops describing what the
field holds.

Rename 'num_params' to 'arg_slot_cnt'. No functional change.

Signed-off-by: Yonghong Song <yonghong.song@linux.dev>
---
 include/linux/bpf_verifier.h |  2 +-
 kernel/bpf/liveness.c        | 10 +++++-----
 kernel/bpf/verifier.c        |  8 ++++----
 3 files changed, 10 insertions(+), 10 deletions(-)

diff --git a/include/linux/bpf_verifier.h b/include/linux/bpf_verifier.h
index edb904424aba..64dfa29f6b45 100644
--- a/include/linux/bpf_verifier.h
+++ b/include/linux/bpf_verifier.h
@@ -1066,7 +1066,7 @@ static inline bool bpf_ret_reg_pair(struct bpf_verifier_env *env, int subprog)
 }
 
 struct bpf_call_summary {
-	u8 num_params;
+	u8 arg_slot_cnt;
 	bool is_void;
 	bool fastcall;
 };
diff --git a/kernel/bpf/liveness.c b/kernel/bpf/liveness.c
index 7165ea325961..44ecdc5b4ec2 100644
--- a/kernel/bpf/liveness.c
+++ b/kernel/bpf/liveness.c
@@ -1434,21 +1434,21 @@ static int record_call_access(struct bpf_verifier_env *env,
 {
 	struct bpf_insn *insn = &env->prog->insnsi[insn_idx];
 	struct bpf_call_summary cs;
-	int r, err, num_params = 5;
+	int r, err, arg_slot_cnt = 5;
 
 	if (bpf_pseudo_call(insn))
 		return 0;
 
 	if (bpf_get_call_summary(env, insn, &cs))
-		num_params = cs.num_params;
+		arg_slot_cnt = cs.arg_slot_cnt;
 
-	for (r = BPF_REG_1; r < BPF_REG_1 + min(num_params, MAX_BPF_FUNC_REG_ARGS); r++) {
+	for (r = BPF_REG_1; r < BPF_REG_1 + min(arg_slot_cnt, MAX_BPF_FUNC_REG_ARGS); r++) {
 		err = record_arg_access(env, instance, insn, &at[r], r - 1, insn_idx);
 		if (err)
 			return err;
 	}
 
-	for (r = 0; r < MAX_STACK_ARG_SLOTS && r < num_params - MAX_BPF_FUNC_REG_ARGS; r++) {
+	for (r = 0; r < MAX_STACK_ARG_SLOTS && r < arg_slot_cnt - MAX_BPF_FUNC_REG_ARGS; r++) {
 		err = record_arg_access(env, instance, insn, &at[MAX_BPF_REG + r],
 					r + MAX_BPF_FUNC_REG_ARGS, insn_idx);
 		if (err)
@@ -2199,7 +2199,7 @@ static void compute_insn_live_regs(struct bpf_verifier_env *env,
 			def = ALL_CALLER_SAVED_REGS;
 			use = def & ~BIT(BPF_REG_0);
 			if (bpf_get_call_summary(env, insn, &cs))
-				use = GENMASK(min_t(u8, cs.num_params, MAX_BPF_FUNC_REG_ARGS), 1);
+				use = GENMASK(min_t(u8, cs.arg_slot_cnt, MAX_BPF_FUNC_REG_ARGS), 1);
 			def = mask_widen(def);
 			use = mask_widen(use);
 			break;
diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c
index 500092a2c924..c520c37bb3c9 100644
--- a/kernel/bpf/verifier.c
+++ b/kernel/bpf/verifier.c
@@ -17973,11 +17973,11 @@ bool bpf_get_call_summary(struct bpf_verifier_env *env, struct bpf_insn *call,
 			       (bpf_verifier_inlines_helper_call(env, call->imm) ||
 				bpf_jit_inlines_helper_call(call->imm));
 		cs->is_void = fn->ret_type == RET_VOID;
-		cs->num_params = 0;
+		cs->arg_slot_cnt = 0;
 		for (i = 0; i < ARRAY_SIZE(fn->arg_type); ++i) {
 			if (fn->arg_type[i] == ARG_DONTCARE)
 				break;
-			cs->num_params++;
+			cs->arg_slot_cnt++;
 		}
 		return true;
 	}
@@ -17989,7 +17989,7 @@ bool bpf_get_call_summary(struct bpf_verifier_env *env, struct bpf_insn *call,
 		if (err < 0)
 			/* error would be reported later */
 			return false;
-		cs->num_params = btf_type_vlen(meta.func_proto);
+		cs->arg_slot_cnt = btf_type_vlen(meta.func_proto);
 		cs->fastcall = meta.kfunc_flags & KF_FASTCALL;
 		cs->is_void = btf_type_is_void(btf_type_by_id(meta.btf, meta.func_proto->type));
 		return true;
@@ -18098,7 +18098,7 @@ static void mark_fastcall_pattern_for_call(struct bpf_verifier_env *env,
 	 * - includes R1-R5 if corresponding parameter has is described
 	 *   in the function prototype.
 	 */
-	clobbered_regs_mask = GENMASK(cs.num_params, cs.is_void ? 1 : 0);
+	clobbered_regs_mask = GENMASK(cs.arg_slot_cnt, cs.is_void ? 1 : 0);
 	/* e.g. if helper call clobbers r{0,1}, expect r{2,3,4,5} in the pattern */
 	expected_regs_mask = ~clobbered_regs_mask & ALL_CALLER_SAVED_REGS;
 
-- 
2.52.0