oslib-posix: add a configure switch to debug stack usage

this adds a knob to track the maximum stack usage of stacks
created by qemu_alloc_stack.

Signed-off-by: Peter Lieven <pl@kamp.de>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
diff --git a/configure b/configure
index df4a247..5751d8e 100755
--- a/configure
+++ b/configure
@@ -296,6 +296,7 @@
 libnfs=""
 coroutine=""
 coroutine_pool=""
+debug_stack_usage="no"
 seccomp=""
 glusterfs=""
 glusterfs_xlator_opt="no"
@@ -1004,6 +1005,8 @@
   ;;
   --enable-coroutine-pool) coroutine_pool="yes"
   ;;
+  --enable-debug-stack-usage) debug_stack_usage="yes"
+  ;;
   --disable-docs) docs="no"
   ;;
   --enable-docs) docs="yes"
@@ -4331,6 +4334,17 @@
   error_exit "'gthread' coroutine backend does not support pool (use --disable-coroutine-pool)"
 fi
 
+if test "$debug_stack_usage" = "yes"; then
+  if test "$cpu" = "ia64" -o "$cpu" = "hppa"; then
+    error_exit "stack usage debugging is not supported for $cpu"
+  fi
+  if test "$coroutine_pool" = "yes"; then
+    echo "WARN: disabling coroutine pool for stack usage debugging"
+    coroutine_pool=no
+  fi
+fi
+
+
 ##########################################
 # check if we have open_by_handle_at
 
@@ -4916,6 +4930,7 @@
 echo "seccomp support   $seccomp"
 echo "coroutine backend $coroutine"
 echo "coroutine pool    $coroutine_pool"
+echo "debug stack usage $debug_stack_usage"
 echo "GlusterFS support $glusterfs"
 echo "Archipelago support $archipelago"
 echo "gcov              $gcov_tool"
@@ -5384,6 +5399,10 @@
   echo "CONFIG_COROUTINE_POOL=0" >> $config_host_mak
 fi
 
+if test "$debug_stack_usage" = "yes" ; then
+  echo "CONFIG_DEBUG_STACK_USAGE=y" >> $config_host_mak
+fi
+
 if test "$open_by_handle_at" = "yes" ; then
   echo "CONFIG_OPEN_BY_HANDLE=y" >> $config_host_mak
 fi