Index: usr.bin/truss/syscall.h
===================================================================
--- usr.bin/truss/syscall.h
+++ usr.bin/truss/syscall.h
@@ -131,6 +131,7 @@
 	Sockprotocol,
 	Socktype,
 	Sysarch,
+	Sysctl,
 	Umtxop,
 	Waitoptions,
 	Whence,
Index: usr.bin/truss/syscalls.c
===================================================================
--- usr.bin/truss/syscalls.c
+++ usr.bin/truss/syscalls.c
@@ -51,6 +51,7 @@
 #include <sys/socket.h>
 #define _WANT_FREEBSD11_STAT
 #include <sys/stat.h>
+#include <sys/sysctl.h>
 #include <sys/time.h>
 #include <sys/un.h>
 #include <sys/wait.h>
@@ -506,6 +507,12 @@
 	  .args = { { Name, 0 }, { Atfd, 1 }, { Name, 2 } } },
 	{ .name = "sysarch", .ret_type = 1, .nargs = 2,
 	  .args = { { Sysarch, 0 }, { Ptr, 1 } } },
+	{ .name = "__sysctl", .ret_type = 1, .nargs = 6,
+	  .args = { { Sysctl, 0 }, { Int, 1 }, { Ptr, 2 }, { Ptr, 3 },
+	            { Ptr, 4 }, { Int, 5 } } },
+	{ .name = "__sysctlbyname", .ret_type = 1, .nargs = 6,
+	  .args = { { Name, 0 }, { Int, 1 }, { Ptr, 2 }, { Ptr, 3 },
+	            { Ptr, 4}, { Int, 5 } } },
 	{ .name = "thr_kill", .ret_type = 1, .nargs = 2,
 	  .args = { { Long, 0 }, { Signal, 1 } } },
 	{ .name = "thr_self", .ret_type = 1, .nargs = 1,
@@ -2267,6 +2274,58 @@
 		print_integer_arg(sysdecode_sysarch_number, fp,
 		    args[sc->offset]);
 		break;
+	case Sysctl: {
+		char name[BUFSIZ];
+		int oid[CTL_MAXNAME], qoid[CTL_MAXNAME+2];
+		size_t i;
+		int len;
+
+		memset(name, 0, sizeof(name));
+		len = args[sc->offset + 1];
+		if (get_struct(pid, (void *)args[sc->offset], oid,
+		    len * sizeof(oid[0])) != -1) {
+			if (oid[0] == CTL_SYSCTL) {
+				fprintf(fp, "\"sysctl.");
+				switch (oid[1]) {
+				case CTL_SYSCTL_DEBUG:
+					fprintf(fp, "debug");
+					break;
+				case CTL_SYSCTL_NAME:
+					fprintf(fp, "name");
+					break;
+				case CTL_SYSCTL_NEXT:
+					fprintf(fp, "next");
+					break;
+				case CTL_SYSCTL_NAME2OID:
+					fprintf(fp, "name2oid");
+					break;
+				case CTL_SYSCTL_OIDFMT:
+					fprintf(fp, "oidfmt");
+					break;
+				case CTL_SYSCTL_OIDDESCR:
+					fprintf(fp, "oiddescr");
+					break;
+				case CTL_SYSCTL_OIDLABEL:
+					fprintf(fp, "oidlabel");
+					break;
+				default:
+					fprintf(fp, "unknown");
+				}
+				fprintf(fp,"\"");
+			} else {
+				qoid[0] = CTL_SYSCTL;
+				qoid[1] = CTL_SYSCTL_NAME;
+				memcpy(qoid+2, oid, len * sizeof(int));
+				i = sizeof(name);
+				if (sysctl(qoid, len + 2, name, &i, 0, 0) == -1)
+					fprintf(fp, "%p",
+					    (void *)args[sc->offset]);
+				else
+					fprintf(fp, "\"%s\"", name);
+			}
+		}
+		break;
+	}
 	case PipeFds:
 		/*
 		 * The pipe() system call in the kernel returns its