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[3.6] bpo-32329: Fix sys.flags.hash_randomization #4875

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Merged
vstinner merged 1 commit into from
Dec 15, 2017
Merged

[3.6] bpo-32329: Fix sys.flags.hash_randomization #4875

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9 changes: 7 additions & 2 deletions Lib/test/test_cmd_line.py
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Original file line number Diff line number Diff line change
Expand Up @@ -426,10 +426,15 @@ def test_hash_randomization(self):

# Verify that sys.flags contains hash_randomization
code = 'import sys; print("random is", sys.flags.hash_randomization)'
rc, out, err = assert_python_ok('-c', code)
self.assertEqual(rc, 0)
rc, out, err = assert_python_ok('-c', code, PYTHONHASHSEED='')
self.assertIn(b'random is 1', out)

rc, out, err = assert_python_ok('-c', code, PYTHONHASHSEED='random')
self.assertIn(b'random is 1', out)

rc, out, err = assert_python_ok('-c', code, PYTHONHASHSEED='0')
self.assertIn(b'random is 0', out)

def test_del___main__(self):
# Issue #15001: PyRun_SimpleFileExFlags() did crash because it kept a
# borrowed reference to the dict of __main__ module and later modify
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2 changes: 2 additions & 0 deletions Misc/NEWS.d/next/Core and Builtins/2017-12-15-00-55-35.bpo-32329.XL1O99.rst
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@@ -0,0 +1,2 @@
``sys.flags.hash_randomization`` is now properly set to 0 when hash
randomization is turned off by ``PYTHONHASHSEED=0``.
1 change: 0 additions & 1 deletion Modules/main.c
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Expand Up @@ -394,7 +394,6 @@ Py_Main(int argc, wchar_t **argv)
exit(1);
}

Py_HashRandomizationFlag = 1;
_PyRandom_Init();

PySys_ResetWarnOptions();
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4 changes: 0 additions & 4 deletions Python/pylifecycle.c
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Expand Up @@ -330,10 +330,6 @@ _Py_InitializeEx_Private(int install_sigs, int install_importlib)
Py_OptimizeFlag = add_flag(Py_OptimizeFlag, p);
if ((p = Py_GETENV("PYTHONDONTWRITEBYTECODE")) && *p != '\0')
Py_DontWriteBytecodeFlag = add_flag(Py_DontWriteBytecodeFlag, p);
/* The variable is only tested for existence here; _PyRandom_Init will
check its value further. */
if ((p = Py_GETENV("PYTHONHASHSEED")) && *p != '\0')
Py_HashRandomizationFlag = add_flag(Py_HashRandomizationFlag, p);
#ifdef MS_WINDOWS
if ((p = Py_GETENV("PYTHONLEGACYWINDOWSFSENCODING")) && *p != '\0')
Py_LegacyWindowsFSEncodingFlag = add_flag(Py_LegacyWindowsFSEncodingFlag, p);
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3 changes: 3 additions & 0 deletions Python/random.c
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Expand Up @@ -565,9 +565,11 @@ _PyRandom_Init(void)
if (seed == 0) {
/* disable the randomized hash */
memset(secret, 0, secret_size);
Py_HashRandomizationFlag = 0;
}
else {
lcg_urandom(seed, secret, secret_size);
Py_HashRandomizationFlag = 1;
}
}
else {
Expand All @@ -582,6 +584,7 @@ _PyRandom_Init(void)
if (res < 0) {
Py_FatalError("failed to get random numbers to initialize Python");
}
Py_HashRandomizationFlag = 1;
}
}

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