group/tg_info/argv: Make utility function to read argv as string

This creates a generic and safe way to read a process argument vector
as string from any context.

fs/procfs/fs_procfsproc.c

@@ -680,7 +680,6 @@ static ssize_t proc_cmdline(FAR struct proc_file_s *procfile,
                             size_t buflen, off_t offset)
 {
   FAR const char *name;
-  FAR char **argv;
   size_t remaining;
   size_t linesize;
   size_t copysize;
@@ -710,45 +709,14 @@ static ssize_t proc_cmdline(FAR struct proc_file_s *procfile,
       return totalsize;
     }
 
-#ifndef CONFIG_DISABLE_PTHREAD
-  /* Show the pthread argument */
+  /* Show the task / thread argument list (skipping over the name) */
 
-  if ((tcb->flags & TCB_FLAG_TTYPE_MASK) == TCB_FLAG_TTYPE_PTHREAD)
-    {
-      FAR struct pthread_tcb_s *ptcb = (FAR struct pthread_tcb_s *)tcb;
-
-      linesize   = procfs_snprintf(procfile->line, STATUS_LINELEN,
-                                   " %p %p\n",
-                                   ptcb->cmn.entry.main, ptcb->arg);
-      copysize   = procfs_memcpy(procfile->line, linesize, buffer,
-                                 remaining, &offset);
-
-      totalsize += copysize;
-      buffer    += copysize;
-      remaining -= copysize;
-
-      return totalsize;
-    }
-#endif
-
-  /* Show the task argument list (skipping over the name) */
-
-  for (argv = tcb->group->tg_info->argv + 1; *argv; argv++)
-    {
-      linesize   = procfs_snprintf(procfile->line, STATUS_LINELEN,
-                                   " %s", *argv);
-      copysize   = procfs_memcpy(procfile->line, linesize, buffer,
-                                 remaining, &offset);
-
-      totalsize += copysize;
-      buffer    += copysize;
-      remaining -= copysize;
-
-      if (totalsize >= buflen)
-        {
-          return totalsize;
-        }
-    }
+  linesize   = group_argvstr(tcb, procfile->line, remaining);
+  copysize   = procfs_memcpy(procfile->line, linesize, buffer,
+                             remaining, &offset);
+  totalsize += copysize;
+  buffer    += copysize;
+  remaining -= copysize;
 
   linesize   = procfs_snprintf(procfile->line, STATUS_LINELEN, "\n");
   copysize   = procfs_memcpy(procfile->line, linesize, buffer,

include/nuttx/sched.h

@@ -1073,6 +1073,25 @@ FAR struct task_tcb_s *nxtask_setup_vfork(start_t retaddr);
 pid_t nxtask_start_vfork(FAR struct task_tcb_s *child);
 void nxtask_abort_vfork(FAR struct task_tcb_s *child, int errcode);
 
+/****************************************************************************
+ * Name: group_argvstr
+ *
+ * Description:
+ *   Safely read the contents of a task's argument vector, into a a safe
+ *   buffer. Function skips the process's name.
+ *
+ * Input Parameters:
+ *   tcb  - tcb of the task.
+ *   args - Output buffer for the argument vector.
+ *   size - Size of the buffer.
+ *
+ * Returned Value:
+ *   The actual string length that was written.
+ *
+ ****************************************************************************/
+
+size_t group_argvstr(FAR struct tcb_s *tcb, FAR char *args, size_t size);
+
 /****************************************************************************
  * Name: group_exitinfo
  *

sched/group/Make.defs

@@ -21,6 +21,7 @@
 CSRCS += group_create.c group_join.c group_leave.c group_find.c
 CSRCS += group_setupstreams.c group_setupidlefiles.c group_setuptaskfiles.c
 CSRCS += group_foreachchild.c group_killchildren.c group_signal.c
+CSRCS += group_argvstr.c
 
 ifeq ($(CONFIG_SCHED_HAVE_PARENT),y)
 ifeq ($(CONFIG_SCHED_CHILD_STATUS),y)

sched/group/group_argvstr.c

@@ -0,0 +1,110 @@
+/****************************************************************************
+ * sched/group/group_argvstr.c
+ *
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.  The
+ * ASF licenses this file to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance with the
+ * License.  You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+ * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.  See the
+ * License for the specific language governing permissions and limitations
+ * under the License.
+ *
+ ****************************************************************************/
+
+/****************************************************************************
+ * Included Files
+ ****************************************************************************/
+
+#include <nuttx/config.h>
+
+#include <sched.h>
+#include <assert.h>
+#include <stddef.h>
+#include <stdio.h>
+
+#include <nuttx/addrenv.h>
+#include <nuttx/tls.h>
+
+#include "sched/sched.h"
+#include "group/group.h"
+
+/****************************************************************************
+ * Public Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Name: group_argvstr
+ *
+ * Description:
+ *   Safely read the contents of a task's argument vector, into a a safe
+ *   buffer. Function skips the process's name.
+ *
+ * Input Parameters:
+ *   tcb  - tcb of the task.
+ *   args - Output buffer for the argument vector.
+ *   size - Size of the buffer.
+ *
+ * Returned Value:
+ *   The actual string length that was written.
+ *
+ ****************************************************************************/
+
+size_t group_argvstr(FAR struct tcb_s *tcb, FAR char *args, size_t size)
+{
+  size_t n = 0;
+#ifdef CONFIG_ARCH_ADDRENV
+  bool saved = false;
+#endif
+
+  /* Perform sanity checks */
+
+  if (!tcb || !tcb->group || !tcb->group->tg_info)
+    {
+      /* Something is very wrong -> get out */
+
+      *args = '\0';
+      return 0;
+    }
+
+#ifdef CONFIG_ARCH_ADDRENV
+  if (tcb->addrenv_own != NULL)
+    {
+      addrenv_select(tcb->addrenv_own);
+      saved = true;
+    }
+#endif
+
+#ifndef CONFIG_DISABLE_PTHREAD
+  if ((tcb->flags & TCB_FLAG_TTYPE_MASK) == TCB_FLAG_TTYPE_PTHREAD)
+    {
+      FAR struct pthread_tcb_s *ptcb = (FAR struct pthread_tcb_s *)tcb;
+
+      n += snprintf(args, size, " %p %p", ptcb->cmn.entry.main, ptcb->arg);
+    }
+  else
+#endif
+    {
+      FAR char **argv = tcb->group->tg_info->argv + 1;
+
+      while (*argv != NULL && n < size)
+        {
+          n += snprintf(args + n, size - n, " %s", *argv++);
+        }
+    }
+
+#ifdef CONFIG_ARCH_ADDRENV
+  if (saved)
+    {
+      addrenv_restore();
+    }
+#endif
+
+  return n < size - 1 ? n : size - 1;
+}

sched/misc/assert.c

@@ -24,7 +24,6 @@
 
 #include <nuttx/config.h>
 
-#include <nuttx/addrenv.h>
 #include <nuttx/arch.h>
 #include <nuttx/board.h>
 #include <nuttx/irq.h>
@@ -43,6 +42,7 @@
 
 #include "irq/irq.h"
 #include "sched/sched.h"
+#include "group/group.h"
 
 /****************************************************************************
  * Pre-processor Definitions
@@ -214,66 +214,6 @@ static void show_stacks(FAR struct tcb_s *rtcb)
 
 #endif
 
-/****************************************************************************
- * Name: get_argv_str
- *
- * Description:
- *   Safely read the contents of a task's argument vector, into a a safe
- *   buffer.
- *
- ****************************************************************************/
-
-static void get_argv_str(FAR struct tcb_s *tcb, FAR char *args, size_t size)
-{
-#ifdef CONFIG_ARCH_ADDRENV
-  bool saved = false;
-#endif
-
-  /* Perform sanity checks */
-
-  if (!tcb || !tcb->group || !tcb->group->tg_info)
-    {
-      /* Something is very wrong -> get out */
-
-      *args = '\0';
-      return;
-    }
-
-#ifdef CONFIG_ARCH_ADDRENV
-  if (tcb->addrenv_own != NULL)
-    {
-      addrenv_select(tcb->addrenv_own);
-      saved = true;
-    }
-#endif
-
-#ifndef CONFIG_DISABLE_PTHREAD
-  if ((tcb->flags & TCB_FLAG_TTYPE_MASK) == TCB_FLAG_TTYPE_PTHREAD)
-    {
-      FAR struct pthread_tcb_s *ptcb = (FAR struct pthread_tcb_s *)tcb;
-
-      snprintf(args, size, " %p %p", ptcb->cmn.entry.main, ptcb->arg);
-    }
-  else
-#endif
-    {
-      FAR char **argv = tcb->group->tg_info->argv + 1;
-      size_t npos = 0;
-
-      while (*argv != NULL && npos < size)
-        {
-          npos += snprintf(args + npos, size - npos, " %s", *argv++);
-        }
-    }
-
-#ifdef CONFIG_ARCH_ADDRENV
-  if (saved)
-    {
-      addrenv_restore();
-    }
-#endif
-}
-
 /****************************************************************************
  * Name: dump_task
  ****************************************************************************/
@@ -313,7 +253,7 @@ static void dump_task(FAR struct tcb_s *tcb, FAR void *arg)
 
   /* Stringify the argument vector */
 
-  get_argv_str(tcb, args, sizeof(args));
+  group_argvstr(tcb, args, sizeof(args));
 
   /* Dump interesting properties of this task */