[Python-checkins] cpython: Issue #11393: limit stack overflow test to 100 MB

Thu Mar 31 11:34:29 CEST 2011

http://hg.python.org/cpython/rev/e289b64f355d
changeset: 69075:e289b64f355d
user: Victor Stinner <victor.stinner at haypocalc.com>
date: Thu Mar 31 11:34:08 2011 +0200
summary:
 Issue #11393: limit stack overflow test to 100 MB
Stop if the stack overflow doesn't occur after allocating 100 MB on the stack.
files:
 Lib/test/test_faulthandler.py | 8 ++-
 Modules/faulthandler.c | 39 +++++++++++++++++++---
 2 files changed, 38 insertions(+), 9 deletions(-)

diff --git a/Lib/test/test_faulthandler.py b/Lib/test/test_faulthandler.py
--- a/Lib/test/test_faulthandler.py
+++ b/Lib/test/test_faulthandler.py
@@ -69,7 +69,7 @@
 return output.splitlines()
 
 def check_fatal_error(self, code, line_number, name_regex,
- filename=None, all_threads=False):
+ filename=None, all_threads=False, other_regex=None):
 """
 Check that the fault handler for fatal errors is enabled and check the
 traceback from the child process output.
@@ -90,6 +90,8 @@
 lineno=line_number,
 name=name_regex,
 header=re.escape(header))
+ if other_regex:
+ regex += '|' + other_regex
 output = self.get_output(code, False, filename)
 output = '\n'.join(output)
 self.assertRegex(output, regex)
@@ -153,7 +155,6 @@
 2,
 'xyz')
 
- @unittest.skipIf(True, 'test disabled, see #11393')
 @unittest.skipIf(not hasattr(faulthandler, '_stack_overflow'),
 'need faulthandler._stack_overflow()')
 def test_stack_overflow(self):
@@ -163,7 +164,8 @@
 faulthandler._stack_overflow()
 """.strip(),
 3,
- '(?:Segmentation fault|Bus error)')
+ '(?:Segmentation fault|Bus error)',
+ other_regex='unable to raise a stack overflow')
 
 def test_gil_released(self):
 self.check_fatal_error("""
diff --git a/Modules/faulthandler.c b/Modules/faulthandler.c
--- a/Modules/faulthandler.c
+++ b/Modules/faulthandler.c
@@ -16,6 +16,9 @@
 # define FAULTHANDLER_USER
 #endif
 
+/* Allocate at maximum 100 MB of the stack to raise the stack overflow */
+#define STACK_OVERFLOW_MAX_SIZE (100*1024*1024)
+
 #define PUTS(fd, str) write(fd, str, strlen(str))
 
 #ifdef HAVE_SIGACTION
@@ -742,15 +745,39 @@
 }
 
 #if defined(HAVE_SIGALTSTACK) && defined(HAVE_SIGACTION)
+void*
+stack_overflow(void *min_sp, void *max_sp, size_t *depth)
+{
+ /* allocate 4096 bytes on the stack at each call */
+ unsigned char buffer[4096];
+ void *sp = &buffer;
+ *depth += 1;
+ if (sp < min_sp || max_sp < sp)
+ return sp;
+ buffer[0] = 1;
+ buffer[4095] = 0;
+ return stack_overflow(min_sp, max_sp, depth);
+}
+
 static PyObject *
 faulthandler_stack_overflow(PyObject *self)
 {
- /* allocate 4096 bytes on the stack at each call */
- unsigned char buffer[4096];
- buffer[0] = 1;
- buffer[4095] = 2;
- faulthandler_stack_overflow(self);
- return PyLong_FromLong(buffer[0] + buffer[4095]);
+ size_t depth, size;
+ void *sp = &depth, *stop;
+
+ depth = 0;
+ stop = stack_overflow(sp - STACK_OVERFLOW_MAX_SIZE,
+ sp + STACK_OVERFLOW_MAX_SIZE,
+ &depth);
+ if (sp < stop)
+ size = stop - sp;
+ else
+ size = sp - stop;
+ PyErr_Format(PyExc_RuntimeError,
+ "unable to raise a stack overflow (allocated %zu bytes "
+ "on the stack, %zu recursive calls)",
+ size, depth);
+ return NULL;
 }
 #endif
 
-- 
Repository URL: http://hg.python.org/cpython
