diff --git a/sys/amd64/amd64/db_trace.c b/sys/amd64/amd64/db_trace.c
--- a/sys/amd64/amd64/db_trace.c
+++ b/sys/amd64/amd64/db_trace.c
@@ -218,7 +218,7 @@
 			break;
 		case SYSCALL:
 			db_printf("--- syscall");
-			db_decode_syscall(tf->tf_rax, td);
+			db_decode_syscall(td, tf->tf_rax);
 			break;
 		case INTERRUPT:
 			db_printf("--- interrupt");
diff --git a/sys/ddb/db_sym.h b/sys/ddb/db_sym.h
--- a/sys/ddb/db_sym.h
+++ b/sys/ddb/db_sym.h
@@ -105,6 +105,6 @@
 void		X_db_symbol_values(db_symtab_t *symtab, c_db_sym_t sym,
 		    const char **namep, db_expr_t *valuep);
 
-void		db_decode_syscall(int number, struct thread *td);
+void		db_decode_syscall(struct thread *td, u_int number);
 
 #endif /* !_DDB_DB_SYM_H_ */
diff --git a/sys/ddb/db_sym.c b/sys/ddb/db_sym.c
--- a/sys/ddb/db_sym.c
+++ b/sys/ddb/db_sym.c
@@ -485,23 +485,15 @@
 }
 
 void
-db_decode_syscall(int number, struct thread *td)
+db_decode_syscall(struct thread *td, u_int number)
 {
 	struct proc *p;
-	c_db_sym_t sym;
-	db_expr_t diff;
-	sy_call_t *f;
-	const char *symname;
 
-	db_printf(" (%d", number);
+	db_printf(" (%u", number);
 	p = (td != NULL) ? td->td_proc : NULL;
-	if (p != NULL && 0 <= number && number < p->p_sysent->sv_size) {
-		f = p->p_sysent->sv_table[number].sy_call;
-		sym = db_search_symbol((db_addr_t)f, DB_STGY_ANY, &diff);
-		if (sym != DB_SYM_NULL && diff == 0) {
-			db_symbol_values(sym, &symname, NULL);
-			db_printf(", %s, %s", p->p_sysent->sv_name, symname);
-		}
+	if (p != NULL) {
+		db_printf(", %s, %s", p->p_sysent->sv_name,
+		    syscallname(p, number));
 	}
 	db_printf(")");
 }
diff --git a/sys/i386/i386/db_trace.c b/sys/i386/i386/db_trace.c
--- a/sys/i386/i386/db_trace.c
+++ b/sys/i386/i386/db_trace.c
@@ -372,7 +372,7 @@
 		break;
 	case SYSCALL:
 		db_printf("--- syscall");
-		db_decode_syscall(tf->tf_eax, td);
+		db_decode_syscall(td, tf->tf_eax);
 		break;
 	case INTERRUPT:
 		db_printf("--- interrupt");
diff --git a/sys/riscv/riscv/db_trace.c b/sys/riscv/riscv/db_trace.c
--- a/sys/riscv/riscv/db_trace.c
+++ b/sys/riscv/riscv/db_trace.c
@@ -97,7 +97,7 @@
 				    tf->tf_scause & SCAUSE_CODE);
 			} else if (tf->tf_scause == SCAUSE_ECALL_USER) {
 				db_printf("--- syscall");
-				db_decode_syscall(td->td_sa.code, td);
+				db_decode_syscall(td, td->td_sa.code);
 				db_printf("\n");
 			} else {
 				db_printf("--- exception %ld, tval = %#lx\n",