From b0b352f78487e1e5a4d3742be91995a2a4e9fb97 Mon Sep 17 00:00:00 2001
From: Ville Juven <ville.juven@unikie.com>
Date: Thu, 22 Dec 2022 10:12:22 +0200
Subject: [PATCH] sched/assert: Fix printing argv when address environments are
 in use

Instantiate the correct address environment when reading the process's
argument vector. Otherwise doing this will crash the system every time,
causing a recursive assert loop.

Also try to do a bit of sanity checking before attempting to read the
process's memory, it might be in a bad state in which case this will
fail anyway.
---
 sched/misc/assert.c | 91 +++++++++++++++++++++++++++++++++++----------
 1 file changed, 72 insertions(+), 19 deletions(-)

diff --git a/sched/misc/assert.c b/sched/misc/assert.c
index de3d738620..1c51e04fd4 100644
--- a/sched/misc/assert.c
+++ b/sched/misc/assert.c
@@ -209,11 +209,80 @@ static void showstacks(void)
 
 #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
+  save_addrenv_t oldenv;
+  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->flags & TCB_FLAG_TTYPE_MASK) != TCB_FLAG_TTYPE_KERNEL)
+    {
+      if ((tcb->group->tg_flags & GROUP_FLAG_ADDRENV) == 0)
+        {
+          /* Process should have address environment, but doesn't */
+
+          *args = '\0';
+          return;
+        }
+
+      up_addrenv_select(&tcb->group->tg_addrenv, &oldenv);
+      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)
+    {
+      up_addrenv_restore(&oldenv);
+    }
+#endif
+}
+
 /****************************************************************************
  * Name: dump_task
  ****************************************************************************/
 
-static void dump_task(struct tcb_s *tcb, void *arg)
+static void dump_task(FAR struct tcb_s *tcb, FAR void *arg)
 {
   char args[64] = "";
 #ifdef CONFIG_STACK_COLORATION
@@ -246,25 +315,9 @@ static void dump_task(struct tcb_s *tcb, void *arg)
     }
 #endif
 
-#ifndef CONFIG_DISABLE_PTHREAD
-  if ((tcb->flags & TCB_FLAG_TTYPE_MASK) == TCB_FLAG_TTYPE_PTHREAD)
-    {
-      struct pthread_tcb_s *ptcb = (struct pthread_tcb_s *)tcb;
+  /* Stringify the argument vector */
 
-      snprintf(args, sizeof(args), " %p %p",
-               ptcb->cmn.entry.main, ptcb->arg);
-    }
-  else
-#endif
-    {
-      char **argv = tcb->group->tg_info->argv + 1;
-      size_t npos = 0;
-
-      while (*argv != NULL && npos < sizeof(args))
-        {
-          npos += snprintf(args + npos, sizeof(args) - npos, " %s", *argv++);
-        }
-    }
+  get_argv_str(tcb, args, sizeof(args));
 
   /* Dump interesting properties of this task */