[Qemu-devel] [Patch] Make usermode stacksize (-s) configurable at compile-time

[Jan-Simon Möller]

Hi !

We encontered problems with the low default value for the stacksize in usermode 
(ok, whats "low"). 
For environments like scratchbox, its hard to use "-s" as qemu is called by 
binfmt mechanism.
The attached patch makes this configurable at compile-time.

Signed-off-by: Jan-Simon Möller <address@hidden>


diff --git a/configure b/configure                                
index 43d87c5..076f45a 100755                                     
--- a/configure                                                   
+++ b/configure                                                   
@@ -220,6 +220,7 @@ uname_release=""                              
 io_thread="no"                                                   
 mixemu="no"                                                      
 kerneldir=""                                                     
+user_mode_stacksize=""                                           
 aix="no"                                                         
 blobs="yes"                                                      
 pkgversion=""                                                    
@@ -557,6 +558,8 @@ for opt do                                    
   ;;                                                             
   --kerneldir=*) kerneldir="$optarg"                             
   ;;
+  --user-mode-stacksize=*) user_mode_stacksize="$optarg"
+  ;;
   --with-pkgversion=*) pkgversion=" ($optarg)"
   ;;
   --disable-docs) docs="no"
@@ -713,6 +716,7 @@ echo "  --enable-linux-aio       enable Linux AIO support"
 echo "  --enable-io-thread       enable IO thread"
 echo "  --disable-blobs          disable installing provided firmware blobs"
 echo "  --kerneldir=PATH         look for kernel includes in PATH"
+echo "  --user-mode-stacksize=   set default stack size in bytes (as -s, only 
in usermode)"
 echo ""
 echo "NOTE: The object files are built at the place where configure is 
launched"
 exit 1
@@ -2576,3 +2580,10 @@ d=libuser
 mkdir -p $d
 rm -f $d/Makefile
 ln -s $source_path/Makefile.user $d/Makefile
+
+# change default stacksize in usermode
+#
+if test "$user_mode_stacksize" != "" ; then
+ echo "user_mode_stack   $user_mode_stacksize"
+ echo "QEMU_CFLAGS+=-DUSER_MODE_STACKSIZE=$user_mode_stacksize" >> 
$config_host_mak
+fi
diff --git a/linux-user/main.c b/linux-user/main.c
index 81a1ada..30c0a87 100644
--- a/linux-user/main.c
+++ b/linux-user/main.c
@@ -51,7 +51,11 @@ const char *qemu_uname_release = CONFIG_UNAME_RELEASE;
 /* XXX: on x86 MAP_GROWSDOWN only works if ESP <= address + 32, so
    we allocate a bigger stack. Need a better solution, for example
    by remapping the process stack directly at the right place */
+#if defined(USER_MODE_STACKSIZE)
+unsigned long x86_stack_size = USER_MODE_STACKSIZE;
+#else
 unsigned long x86_stack_size = 512 * 1024;
+#endif

 void gemu_log(const char *fmt, ...)
 {

usermode_stacksize.diff
Description: Text Data