diff --git a/src/ttyname.c b/src/ttyname.c
index 6d70819ef..da98b031c 100644
--- a/src/ttyname.c
+++ b/src/ttyname.c
@@ -334,8 +334,7 @@ sudo_ttyname_dev(dev_t rdev)
 #if defined(sudo_kp_tdev)
 /*
  * Return a string from ttyname() containing the tty to which the process is
- * attached or NULL if there is no tty associated with the process (or its
- * parent).  First tries sysctl using the current pid, then the parent's pid.
+ * attached or NULL if the process has no controlling tty.
  */
 char *
 get_process_ttyname(void)
@@ -343,38 +342,36 @@ get_process_ttyname(void)
     char *tty = NULL;
     struct sudo_kinfo_proc *ki_proc = NULL;
     size_t size = sizeof(*ki_proc);
-    int i, mib[6], rc;
+    int mib[6], rc;
     debug_decl(get_process_ttyname, SUDO_DEBUG_UTIL)
 
     /*
-     * Lookup tty for this process and, failing that, our parent.
-     * Even if we redirect std{in,out,err} the kernel should still know.
+     * Lookup controlling tty for this process via sysctl.
+     * This will work even if std{in,out,err} are redirected.
      */
-    for (i = 0; tty == NULL && i < 2; i++) {
-	mib[0] = CTL_KERN;
-	mib[1] = SUDO_KERN_PROC;
-	mib[2] = KERN_PROC_PID;
-	mib[3] = i ? (int)getppid() : (int)getpid();
-	mib[4] = sizeof(*ki_proc);
-	mib[5] = 1;
-	do {
-	    size += size / 10;
-	    ki_proc = erealloc(ki_proc, size);
-	    rc = sysctl(mib, sudo_kp_namelen, ki_proc, &size, NULL, 0);
-	} while (rc == -1 && errno == ENOMEM);
-	if (rc != -1) {
-	    if (ki_proc->sudo_kp_tdev != (dev_t)-1) {
-		tty = sudo_ttyname_dev(ki_proc->sudo_kp_tdev);
-		if (tty == NULL) {
-		    sudo_debug_printf(SUDO_DEBUG_WARN,
-			"unable to map device number %u to name",
-			ki_proc->sudo_kp_tdev);
-		}
+    mib[0] = CTL_KERN;
+    mib[1] = SUDO_KERN_PROC;
+    mib[2] = KERN_PROC_PID;
+    mib[3] = (int)getpid();
+    mib[4] = sizeof(*ki_proc);
+    mib[5] = 1;
+    do {
+	size += size / 10;
+	ki_proc = erealloc(ki_proc, size);
+	rc = sysctl(mib, sudo_kp_namelen, ki_proc, &size, NULL, 0);
+    } while (rc == -1 && errno == ENOMEM);
+    if (rc != -1) {
+	if (ki_proc->sudo_kp_tdev != (dev_t)-1) {
+	    tty = sudo_ttyname_dev(ki_proc->sudo_kp_tdev);
+	    if (tty == NULL) {
+		sudo_debug_printf(SUDO_DEBUG_WARN,
+		    "unable to map device number %u to name",
+		    ki_proc->sudo_kp_tdev);
 	    }
-	} else {
-	    sudo_debug_printf(SUDO_DEBUG_WARN,
-		"unable to resolve tty via KERN_PROC: %s", strerror(errno));
 	}
+    } else {
+	sudo_debug_printf(SUDO_DEBUG_WARN,
+	    "unable to resolve tty via KERN_PROC: %s", strerror(errno));
     }
     efree(ki_proc);
 
@@ -383,8 +380,7 @@ get_process_ttyname(void)
 #elif defined(HAVE_STRUCT_PSINFO_PR_TTYDEV)
 /*
  * Return a string from ttyname() containing the tty to which the process is
- * attached or NULL if there is no tty associated with the process (or its
- * parent).  First tries /proc/pid/psinfo, then /proc/ppid/psinfo.
+ * attached or NULL if the process has no controlling tty.
  */
 char *
 get_process_ttyname(void)
@@ -392,20 +388,17 @@ get_process_ttyname(void)
     char path[PATH_MAX], *tty = NULL;
     struct psinfo psinfo;
     ssize_t nread;
-    int i, fd;
+    int fd;
     debug_decl(get_process_ttyname, SUDO_DEBUG_UTIL)
 
     /* Try to determine the tty from pr_ttydev in /proc/pid/psinfo. */
-    for (i = 0; tty == NULL && i < 2; i++) {
-	(void)snprintf(path, sizeof(path), "/proc/%u/psinfo",
-	    i ? (unsigned int)getppid() : (unsigned int)getpid());
-	if ((fd = open(path, O_RDONLY, 0)) == -1)
-	    continue;
+    snprintf(path, sizeof(path), "/proc/%u/psinfo", (unsigned int)getpid());
+    if ((fd = open(path, O_RDONLY, 0)) != -1) {
 	nread = read(fd, &psinfo, sizeof(psinfo));
 	close(fd);
 	if (nread == (ssize_t)sizeof(psinfo)) {
 	    dev_t rdev = (dev_t)psinfo.pr_ttydev;
-#ifdef DEVNO64
+#if defined(_AIX) && defined(DEVNO64)
 	    if (psinfo.pr_ttydev & DEVNO64)
 		rdev = makedev(major64(psinfo.pr_ttydev), minor64(psinfo.pr_ttydev));
 #endif
@@ -419,26 +412,20 @@ get_process_ttyname(void)
 #elif defined(__linux__)
 /*
  * Return a string from ttyname() containing the tty to which the process is
- * attached or NULL if there is no tty associated with the process (or its
- * parent).  First tries field 7 in /proc/pid/stat, then /proc/ppid/stat.
+ * attached or NULL if the process has no controlling tty.
  */
 char *
 get_process_ttyname(void)
 {
-    char *line = NULL, *tty = NULL;
+    char path[PATH_MAX], *line = NULL, *tty = NULL;
     size_t linesize = 0;
     ssize_t len;
-    int i;
+    FILE *fp;
     debug_decl(get_process_ttyname, SUDO_DEBUG_UTIL)
 
     /* Try to determine the tty from tty_nr in /proc/pid/stat. */
-    for (i = 0; tty == NULL && i < 2; i++) {
-	FILE *fp;
-	char path[PATH_MAX];
-	(void)snprintf(path, sizeof(path), "/proc/%u/stat",
-	    i ? (unsigned int)getppid() : (unsigned int)getpid());
-	if ((fp = fopen(path, "r")) == NULL)
-	    continue;
+    snprintf(path, sizeof(path), "/proc/%u/stat", (unsigned int)getpid());
+    if ((fp = fopen(path, "r")) != NULL) {
 	len = getline(&line, &linesize, fp);
 	fclose(fp);
 	if (len != -1) {
@@ -456,33 +443,28 @@ get_process_ttyname(void)
 		}
 	    }
 	}
+	efree(line);
     }
-    efree(line);
 
     debug_return_str(tty);
 }
 #elif HAVE_PSTAT_GETPROC
 /*
  * Return a string from ttyname() containing the tty to which the process is
- * attached or NULL if there is no tty associated with the process (or its
- * parent).
+ * attached or NULL if the process has no controlling tty.
  */
 char *
 get_process_ttyname(void)
 {
     struct pst_status pstat;
     char *tty = NULL;
-    int i;
     debug_decl(get_process_ttyname, SUDO_DEBUG_UTIL)
 
     /* Try to determine the tty from psdev in struct pst_status. */
-    for (i = 0; tty == NULL && i < 2; i++) {
-	const int pid = i ? (int)getppid() : (int)getpid();
-	if (pstat_getproc(&pstat, sizeof(pstat), 0, pid) != -1) {
-	    if (pstat.pst_term.psd_major != -1 && pstat.pst_term.psd_minor != -1) {
-		tty = sudo_ttyname_dev(makedev(pstat.pst_term.psd_major,
-		    pstat.pst_term.psd_minor));
-	    }
+    if (pstat_getproc(&pstat, sizeof(pstat), 0, (int)getpid()) != -1) {
+	if (pstat.pst_term.psd_major != -1 && pstat.pst_term.psd_minor != -1) {
+	    tty = sudo_ttyname_dev(makedev(pstat.pst_term.psd_major,
+		pstat.pst_term.psd_minor));
 	}
     }
     debug_return_str(tty);
@@ -490,8 +472,7 @@ get_process_ttyname(void)
 #else
 /*
  * Return a string from ttyname() containing the tty to which the process is
- * attached or NULL if there is no tty associated with the process.
- * parent).
+ * attached or NULL if the process has no controlling tty.
  */
 char *
 get_process_ttyname(void)