Issue #440

Limit the amount of memory that is requested from alloca()
for temporary conversion of arguments.  Non-small requests are
instead handled with PyObject_Malloc() and PyObject_Free().

3 files changed, 33 insertions, 0 deletions

diff --git a/testing/cffi0/test_function.py b/testing/cffi0/test_function.py
index d1f9ce4..6312707 100644
--- a/testing/cffi0/test_function.py
+++ b/testing/cffi0/test_function.py
@@ -520,3 +520,16 @@ class TestFunction(object):
         assert str(e.value).startswith("library '")
         assert str(e.value).endswith("' has already been closed")
         ffi.dlclose(lib)    # does not raise
+
+    def test_passing_large_list(self):
+        if self.Backend is CTypesBackend:
+            py.test.skip("the ctypes backend doesn't support this")
+        ffi = FFI(backend=self.Backend())
+        ffi.cdef("""
+            void getenv(char *);
+        """)
+        needs_dlopen_none()
+        m = ffi.dlopen(None)
+        arg = [b"F", b"O", b"O"] + [b"\x00"] * 20000000
+        x = m.getenv(arg)
+        assert x is None
diff --git a/testing/cffi0/test_verify.py b/testing/cffi0/test_verify.py
index 52ce214..3a1c0b9 100644
--- a/testing/cffi0/test_verify.py
+++ b/testing/cffi0/test_verify.py
@@ -2550,3 +2550,13 @@ def test_arithmetic_in_cdef():
         """.replace('?', str(a)))
         # the verify() crashes if the values in the enum are different from
         # the values we computed ourselves from the cdef()
+
+def test_passing_large_list():
+    ffi = FFI()
+    ffi.cdef("""void passing_large_list(long[]);""")
+    lib = ffi.verify("""
+        static void passing_large_list(long a[]) { }
+    """)
+    arg = list(range(20000000))
+    lib.passing_large_list(arg)
+    # assert did not segfault
diff --git a/testing/cffi1/test_recompiler.py b/testing/cffi1/test_recompiler.py
index 1b837f8..78abaa0 100644
--- a/testing/cffi1/test_recompiler.py
+++ b/testing/cffi1/test_recompiler.py
@@ -2445,3 +2445,13 @@ def test_struct_with_func_with_struct_arg():
         };
     """)
     py.test.raises(RuntimeError, ffi.new, "struct BinaryTree *")
+
+def test_passing_large_list():
+    ffi = FFI()
+    ffi.cdef("""void passing_large_list(long[]);""")
+    lib = verify(ffi, "test_passing_large_list", """
+        static void passing_large_list(long a[]) { }
+    """)
+    arg = list(range(20000000))
+    lib.passing_large_list(arg)
+    # assert did not segfault