diff options
| -rw-r--r-- | Lib/test/test_mmap.py | 51 | ||||
| -rw-r--r-- | Misc/NEWS | 4 | ||||
| -rw-r--r-- | Modules/mmapmodule.c | 107 |
3 files changed, 112 insertions, 50 deletions
diff --git a/Lib/test/test_mmap.py b/Lib/test/test_mmap.py index 8f20d96..cbef374 100644 --- a/Lib/test/test_mmap.py +++ b/Lib/test/test_mmap.py @@ -1,4 +1,4 @@ -from test.support import TESTFN, run_unittest, import_module +from test.support import TESTFN, run_unittest, import_module, unlink, requires import unittest import os import re @@ -646,9 +646,56 @@ class MmapTests(unittest.TestCase): "wrong exception raised in context manager") self.assertTrue(m.closed, "context manager failed") +class LargeMmapTests(unittest.TestCase): + + def setUp(self): + unlink(TESTFN) + + def tearDown(self): + unlink(TESTFN) + + def _working_largefile(self): + # Only run if the current filesystem supports large files. + f = open(TESTFN, 'wb', buffering=0) + try: + f.seek(0x80000001) + f.write(b'x') + f.flush() + except (IOError, OverflowError): + raise unittest.SkipTest("filesystem does not have largefile support") + finally: + f.close() + unlink(TESTFN) + + def test_large_offset(self): + if sys.platform[:3] == 'win' or sys.platform == 'darwin': + requires('largefile', + 'test requires %s bytes and a long time to run' % str(0x180000000)) + self._working_largefile() + with open(TESTFN, 'wb') as f: + f.seek(0x14FFFFFFF) + f.write(b" ") + + with open(TESTFN, 'rb') as f: + with mmap.mmap(f.fileno(), 0, offset=0x140000000, access=mmap.ACCESS_READ) as m: + self.assertEqual(m[0xFFFFFFF], 32) + + def test_large_filesize(self): + if sys.platform[:3] == 'win' or sys.platform == 'darwin': + requires('largefile', + 'test requires %s bytes and a long time to run' % str(0x180000000)) + self._working_largefile() + with open(TESTFN, 'wb') as f: + f.seek(0x17FFFFFFF) + f.write(b" ") + + with open(TESTFN, 'rb') as f: + with mmap.mmap(f.fileno(), 0x10000, access=mmap.ACCESS_READ) as m: + self.assertEqual(m.size(), 0x180000000) + def test_main(): - run_unittest(MmapTests) + run_unittest(MmapTests, LargeMmapTests) if __name__ == '__main__': test_main() @@ -27,6 +27,10 @@ Core and Builtins Library ------- +- Issue #4681: Allow mmap() to work on file sizes and offsets larger than + 4GB, even on 32-bit builds. Initial patch by Ross Lagerwall, adapted for + 32-bit Windows. + - Issue #11169: compileall module uses repr() to format filenames and paths to escape surrogate characters and show spaces. diff --git a/Modules/mmapmodule.c b/Modules/mmapmodule.c index a9049ed..02e0989 100644 --- a/Modules/mmapmodule.c +++ b/Modules/mmapmodule.c @@ -90,7 +90,11 @@ typedef struct { char * data; size_t size; size_t pos; /* relative to offset */ - size_t offset; +#ifdef MS_WINDOWS + PY_LONG_LONG offset; +#else + off_t offset; +#endif int exports; #ifdef MS_WINDOWS @@ -433,7 +437,11 @@ mmap_size_method(mmap_object *self, PyErr_SetFromErrno(mmap_module_error); return NULL; } - return PyLong_FromSsize_t(buf.st_size); +#ifdef HAVE_LARGEFILE_SUPPORT + return PyLong_FromLongLong(buf.st_size); +#else + return PyLong_FromLong(buf.st_size); +#endif } #endif /* UNIX */ } @@ -467,17 +475,10 @@ mmap_resize_method(mmap_object *self, CloseHandle(self->map_handle); self->map_handle = NULL; /* Move to the desired EOF position */ -#if SIZEOF_SIZE_T > 4 newSizeHigh = (DWORD)((self->offset + new_size) >> 32); newSizeLow = (DWORD)((self->offset + new_size) & 0xFFFFFFFF); off_hi = (DWORD)(self->offset >> 32); off_lo = (DWORD)(self->offset & 0xFFFFFFFF); -#else - newSizeHigh = 0; - newSizeLow = (DWORD)(self->offset + new_size); - off_hi = 0; - off_lo = (DWORD)self->offset; -#endif SetFilePointer(self->file_handle, newSizeLow, &newSizeHigh, FILE_BEGIN); /* Change the size of the file */ @@ -1051,6 +1052,12 @@ _GetMapSize(PyObject *o, const char* param) } #ifdef UNIX +#ifdef HAVE_LARGEFILE_SUPPORT +#define _Py_PARSE_OFF_T "L" +#else +#define _Py_PARSE_OFF_T "l" +#endif + static PyObject * new_mmap_object(PyTypeObject *type, PyObject *args, PyObject *kwdict) { @@ -1058,8 +1065,9 @@ new_mmap_object(PyTypeObject *type, PyObject *args, PyObject *kwdict) struct stat st; #endif mmap_object *m_obj; - PyObject *map_size_obj = NULL, *offset_obj = NULL; - Py_ssize_t map_size, offset; + PyObject *map_size_obj = NULL; + Py_ssize_t map_size; + off_t offset = 0; int fd, flags = MAP_SHARED, prot = PROT_WRITE | PROT_READ; int devzero = -1; int access = (int)ACCESS_DEFAULT; @@ -1067,16 +1075,18 @@ new_mmap_object(PyTypeObject *type, PyObject *args, PyObject *kwdict) "flags", "prot", "access", "offset", NULL}; - if (!PyArg_ParseTupleAndKeywords(args, kwdict, "iO|iiiO", keywords, + if (!PyArg_ParseTupleAndKeywords(args, kwdict, "iO|iii" _Py_PARSE_OFF_T, keywords, &fd, &map_size_obj, &flags, &prot, - &access, &offset_obj)) + &access, &offset)) return NULL; map_size = _GetMapSize(map_size_obj, "size"); if (map_size < 0) return NULL; - offset = _GetMapSize(offset_obj, "offset"); - if (offset < 0) + if (offset < 0) { + PyErr_SetString(PyExc_OverflowError, + "memory mapped offset must be positive"); return NULL; + } if ((access != (int)ACCESS_DEFAULT) && ((flags != MAP_SHARED) || (prot != (PROT_WRITE | PROT_READ)))) @@ -1121,8 +1131,14 @@ new_mmap_object(PyTypeObject *type, PyObject *args, PyObject *kwdict) "mmap offset is greater than file size"); return NULL; } - map_size = st.st_size - offset; - } else if ((size_t)offset + (size_t)map_size > st.st_size) { + off_t calc_size = st.st_size - offset; + map_size = calc_size; + if (map_size != calc_size) { + PyErr_SetString(PyExc_ValueError, + "mmap length is too large"); + return NULL; + } + } else if (offset + (size_t)map_size > st.st_size) { PyErr_SetString(PyExc_ValueError, "mmap length is greater than file size"); return NULL; @@ -1183,12 +1199,19 @@ new_mmap_object(PyTypeObject *type, PyObject *args, PyObject *kwdict) #endif /* UNIX */ #ifdef MS_WINDOWS + +/* A note on sizes and offsets: while the actual map size must hold in a + Py_ssize_t, both the total file size and the start offset can be longer + than a Py_ssize_t, so we use PY_LONG_LONG which is always 64-bit. +*/ + static PyObject * new_mmap_object(PyTypeObject *type, PyObject *args, PyObject *kwdict) { mmap_object *m_obj; - PyObject *map_size_obj = NULL, *offset_obj = NULL; - Py_ssize_t map_size, offset; + PyObject *map_size_obj = NULL; + Py_ssize_t map_size; + PY_LONG_LONG offset = 0, size; DWORD off_hi; /* upper 32 bits of offset */ DWORD off_lo; /* lower 32 bits of offset */ DWORD size_hi; /* upper 32 bits of size */ @@ -1203,9 +1226,9 @@ new_mmap_object(PyTypeObject *type, PyObject *args, PyObject *kwdict) "tagname", "access", "offset", NULL }; - if (!PyArg_ParseTupleAndKeywords(args, kwdict, "iO|ziO", keywords, + if (!PyArg_ParseTupleAndKeywords(args, kwdict, "iO|ziL", keywords, &fileno, &map_size_obj, - &tagname, &access, &offset_obj)) { + &tagname, &access, &offset)) { return NULL; } @@ -1230,9 +1253,11 @@ new_mmap_object(PyTypeObject *type, PyObject *args, PyObject *kwdict) map_size = _GetMapSize(map_size_obj, "size"); if (map_size < 0) return NULL; - offset = _GetMapSize(offset_obj, "offset"); - if (offset < 0) + if (offset < 0) { + PyErr_SetString(PyExc_OverflowError, + "memory mapped offset must be positive"); return NULL; + } /* assume -1 and 0 both mean invalid filedescriptor to 'anonymously' map memory. @@ -1296,28 +1321,26 @@ new_mmap_object(PyTypeObject *type, PyObject *args, PyObject *kwdict) return PyErr_SetFromWindowsErr(dwErr); } -#if SIZEOF_SIZE_T > 4 - m_obj->size = (((size_t)high)<<32) + low; -#else - if (high) - /* File is too large to map completely */ - m_obj->size = (size_t)-1; - else - m_obj->size = low; -#endif - if (offset >= m_obj->size) { + size = (((PY_LONG_LONG) high) << 32) + low; + if (offset >= size) { PyErr_SetString(PyExc_ValueError, "mmap offset is greater than file size"); Py_DECREF(m_obj); return NULL; } - m_obj->size -= offset; + if (offset - size > PY_SSIZE_T_MAX) + /* Map area too large to fit in memory */ + m_obj->size = (Py_ssize_t) -1; + else + m_obj->size = (Py_ssize_t) (size - offset); } else { m_obj->size = map_size; + size = offset + map_size; } } else { m_obj->size = map_size; + size = offset + map_size; } /* set the initial position */ @@ -1338,22 +1361,10 @@ new_mmap_object(PyTypeObject *type, PyObject *args, PyObject *kwdict) m_obj->tagname = NULL; m_obj->access = (access_mode)access; - /* DWORD is a 4-byte int. If we're on a box where size_t consumes - * more than 4 bytes, we need to break it apart. Else (size_t - * consumes 4 bytes), C doesn't define what happens if we shift - * right by 32, so we need different code. - */ -#if SIZEOF_SIZE_T > 4 - size_hi = (DWORD)((offset + m_obj->size) >> 32); - size_lo = (DWORD)((offset + m_obj->size) & 0xFFFFFFFF); + size_hi = (DWORD)(size >> 32); + size_lo = (DWORD)(size & 0xFFFFFFFF); off_hi = (DWORD)(offset >> 32); off_lo = (DWORD)(offset & 0xFFFFFFFF); -#else - size_hi = 0; - size_lo = (DWORD)(offset + m_obj->size); - off_hi = 0; - off_lo = (DWORD)offset; -#endif /* For files, it would be sufficient to pass 0 as size. For anonymous maps, we have to pass the size explicitly. */ m_obj->map_handle = CreateFileMapping(m_obj->file_handle, |