Issue #22896: Avoid to use PyObject_AsCharBuffer(), PyObject_AsReadBuffer()

and PyObject_AsWriteBuffer().

18 files changed, 420 insertions, 395 deletions

diff --git a/Include/bytes_methods.h b/Include/bytes_methods.h
index 290488124a..11d5f42752 100644
--- a/Include/bytes_methods.h
+++ b/Include/bytes_methods.h
@@ -22,7 +22,7 @@ extern void _Py_bytes_capitalize(char *result, char *s, Py_ssize_t len);
 extern void _Py_bytes_swapcase(char *result, char *s, Py_ssize_t len);
 
 /* The maketrans() static method. */
-extern PyObject* _Py_bytes_maketrans(PyObject *frm, PyObject *to);
+extern PyObject* _Py_bytes_maketrans(Py_buffer *frm, Py_buffer *to);
 
 /* Shared __doc__ strings. */
 extern const char _Py_isspace__doc__[];
diff --git a/Lib/ctypes/test/test_frombuffer.py b/Lib/ctypes/test/test_frombuffer.py
index ffb27a6ea3..6aa2d1c591 100644
--- a/Lib/ctypes/test/test_frombuffer.py
+++ b/Lib/ctypes/test/test_frombuffer.py
@@ -10,7 +10,7 @@ class X(Structure):
         self._init_called = True
 
 class Test(unittest.TestCase):
-    def test_fom_buffer(self):
+    def test_from_buffer(self):
         a = array.array("i", range(16))
         x = (c_int * 16).from_buffer(a)
 
@@ -23,25 +23,37 @@ class Test(unittest.TestCase):
         a[0], a[-1] = 200, -200
         self.assertEqual(x[:], a.tolist())
 
-        self.assertIn(a, x._objects.values())
+        self.assertRaises(BufferError, a.append, 100)
+        self.assertRaises(BufferError, a.pop)
 
-        self.assertRaises(ValueError,
-                          c_int.from_buffer, a, -1)
+        del x; del y; gc.collect(); gc.collect(); gc.collect()
+        a.append(100)
+        a.pop()
+        x = (c_int * 16).from_buffer(a)
+
+        self.assertIn(a, [obj.obj if isinstance(obj, memoryview) else obj
+                          for obj in x._objects.values()])
 
         expected = x[:]
         del a; gc.collect(); gc.collect(); gc.collect()
         self.assertEqual(x[:], expected)
 
-        self.assertRaises(TypeError,
-                          (c_char * 16).from_buffer, "a" * 16)
+        with self.assertRaises(TypeError):
+            (c_char * 16).from_buffer(b"a" * 16)
+        with self.assertRaises(TypeError):
+            (c_char * 16).from_buffer("a" * 16)
 
-    def test_fom_buffer_with_offset(self):
+    def test_from_buffer_with_offset(self):
         a = array.array("i", range(16))
         x = (c_int * 15).from_buffer(a, sizeof(c_int))
 
         self.assertEqual(x[:], a.tolist()[1:])
-        self.assertRaises(ValueError, lambda: (c_int * 16).from_buffer(a, sizeof(c_int)))
-        self.assertRaises(ValueError, lambda: (c_int * 1).from_buffer(a, 16 * sizeof(c_int)))
+        with self.assertRaises(ValueError):
+            c_int.from_buffer(a, -1)
+        with self.assertRaises(ValueError):
+            (c_int * 16).from_buffer(a, sizeof(c_int))
+        with self.assertRaises(ValueError):
+            (c_int * 1).from_buffer(a, 16 * sizeof(c_int))
 
     def test_from_buffer_copy(self):
         a = array.array("i", range(16))
@@ -56,26 +68,30 @@ class Test(unittest.TestCase):
         a[0], a[-1] = 200, -200
         self.assertEqual(x[:], list(range(16)))
 
-        self.assertEqual(x._objects, None)
+        a.append(100)
+        self.assertEqual(x[:], list(range(16)))
 
-        self.assertRaises(ValueError,
-                          c_int.from_buffer, a, -1)
+        self.assertEqual(x._objects, None)
 
         del a; gc.collect(); gc.collect(); gc.collect()
         self.assertEqual(x[:], list(range(16)))
 
         x = (c_char * 16).from_buffer_copy(b"a" * 16)
         self.assertEqual(x[:], b"a" * 16)
+        with self.assertRaises(TypeError):
+            (c_char * 16).from_buffer_copy("a" * 16)
 
-    def test_fom_buffer_copy_with_offset(self):
+    def test_from_buffer_copy_with_offset(self):
         a = array.array("i", range(16))
         x = (c_int * 15).from_buffer_copy(a, sizeof(c_int))
 
         self.assertEqual(x[:], a.tolist()[1:])
-        self.assertRaises(ValueError,
-                          (c_int * 16).from_buffer_copy, a, sizeof(c_int))
-        self.assertRaises(ValueError,
-                          (c_int * 1).from_buffer_copy, a, 16 * sizeof(c_int))
+        with self.assertRaises(ValueError):
+            c_int.from_buffer_copy(a, -1)
+        with self.assertRaises(ValueError):
+            (c_int * 16).from_buffer_copy(a, sizeof(c_int))
+        with self.assertRaises(ValueError):
+            (c_int * 1).from_buffer_copy(a, 16 * sizeof(c_int))
 
 if __name__ == '__main__':
     unittest.main()
diff --git a/Misc/NEWS b/Misc/NEWS
index 649e804513..62e5794871 100644
--- a/Misc/NEWS
+++ b/Misc/NEWS
@@ -10,6 +10,9 @@ Release date: TBA
 Core and Builtins
 -----------------
 
+- Issue #22896: Avoid using PyObject_AsCharBuffer(), PyObject_AsReadBuffer()
+  and PyObject_AsWriteBuffer().
+
 - Issue #21295: Revert some changes (issue #16795) to AST line numbers and
   column offsets that constituted a regression.
 
diff --git a/Modules/_codecsmodule.c b/Modules/_codecsmodule.c
index f25297a41a..bf408afeca 100644
--- a/Modules/_codecsmodule.c
+++ b/Modules/_codecsmodule.c
@@ -288,8 +288,6 @@ unicode_internal_decode(PyObject *self,
 {
     PyObject *obj;
     const char *errors = NULL;
-    const char *data;
-    Py_ssize_t size;
 
     if (!PyArg_ParseTuple(args, "O|z:unicode_internal_decode",
                           &obj, &errors))
@@ -302,11 +300,16 @@ unicode_internal_decode(PyObject *self,
         return codec_tuple(obj, PyUnicode_GET_LENGTH(obj));
     }
     else {
-        if (PyObject_AsReadBuffer(obj, (const void **)&data, &size))
+        Py_buffer view;
+        PyObject *result;
+        if (PyObject_GetBuffer(obj, &view, PyBUF_SIMPLE) != 0)
             return NULL;
 
-        return codec_tuple(_PyUnicode_DecodeUnicodeInternal(data, size, errors),
-                           size);
+        result = codec_tuple(
+                _PyUnicode_DecodeUnicodeInternal(view.buf, view.len, errors),
+                view.len);
+        PyBuffer_Release(&view);
+        return result;
     }
 }
 
@@ -731,8 +734,6 @@ unicode_internal_encode(PyObject *self,
 {
     PyObject *obj;
     const char *errors = NULL;
-    const char *data;
-    Py_ssize_t len, size;
 
     if (PyErr_WarnEx(PyExc_DeprecationWarning,
                      "unicode_internal codec has been deprecated",
@@ -745,6 +746,7 @@ unicode_internal_encode(PyObject *self,
 
     if (PyUnicode_Check(obj)) {
         Py_UNICODE *u;
+        Py_ssize_t len, size;
 
         if (PyUnicode_READY(obj) < 0)
             return NULL;
@@ -759,9 +761,13 @@ unicode_internal_encode(PyObject *self,
                            PyUnicode_GET_LENGTH(obj));
     }
     else {
-        if (PyObject_AsReadBuffer(obj, (const void **)&data, &size))
+        Py_buffer view;
+        PyObject *result;
+        if (PyObject_GetBuffer(obj, &view, PyBUF_SIMPLE) != 0)
             return NULL;
-        return codec_tuple(PyBytes_FromStringAndSize(data, size), size);
+        result = codec_tuple(PyBytes_FromStringAndSize(view.buf, view.len), view.len);
+        PyBuffer_Release(&view);
+        return result;
     }
 }
 
diff --git a/Modules/_ctypes/_ctypes.c b/Modules/_ctypes/_ctypes.c
index f771473aa8..c2889d2ec3 100644
--- a/Modules/_ctypes/_ctypes.c
+++ b/Modules/_ctypes/_ctypes.c
@@ -463,39 +463,45 @@ KeepRef(CDataObject *target, Py_ssize_t index, PyObject *keep);
 static PyObject *
 CDataType_from_buffer(PyObject *type, PyObject *args)
 {
-    void *buffer;
-    Py_ssize_t buffer_len;
+    Py_buffer buffer;
     Py_ssize_t offset = 0;
-    PyObject *obj, *result;
+    PyObject *result, *mv;
     StgDictObject *dict = PyType_stgdict(type);
     assert (dict);
 
-    if (!PyArg_ParseTuple(args, "O|n:from_buffer", &obj, &offset))
-        return NULL;
-
-    if (-1 == PyObject_AsWriteBuffer(obj, &buffer, &buffer_len))
+    if (!PyArg_ParseTuple(args, "w*|n:from_buffer", &buffer, &offset))
         return NULL;
 
     if (offset < 0) {
         PyErr_SetString(PyExc_ValueError,
                         "offset cannot be negative");
+        PyBuffer_Release(&buffer);
         return NULL;
     }
-    if (dict->size > buffer_len - offset) {
+    if (dict->size > buffer.len - offset) {
         PyErr_Format(PyExc_ValueError,
                      "Buffer size too small (%zd instead of at least %zd bytes)",
-                     buffer_len, dict->size + offset);
+                     buffer.len, dict->size + offset);
+        PyBuffer_Release(&buffer);
         return NULL;
     }
 
-    result = PyCData_AtAddress(type, (char *)buffer + offset);
-    if (result == NULL)
+    result = PyCData_AtAddress(type, (char *)buffer.buf + offset);
+    if (result == NULL) {
+        PyBuffer_Release(&buffer);
         return NULL;
+    }
 
-    Py_INCREF(obj);
-    if (-1 == KeepRef((CDataObject *)result, -1, obj)) {
+    mv = PyMemoryView_FromBuffer(&buffer);
+    if (mv == NULL) {
+        PyBuffer_Release(&buffer);
         return NULL;
     }
+    /* Hack the memoryview so that it will release the buffer. */
+    ((PyMemoryViewObject *)mv)->mbuf->master.obj = buffer.obj;
+    ((PyMemoryViewObject *)mv)->view.obj = buffer.obj;
+    if (-1 == KeepRef((CDataObject *)result, -1, mv))
+        result = NULL;
     return result;
 }
 
@@ -508,37 +514,36 @@ GenericPyCData_new(PyTypeObject *type, PyObject *args, PyObject *kwds);
 static PyObject *
 CDataType_from_buffer_copy(PyObject *type, PyObject *args)
 {
-    const void *buffer;
-    Py_ssize_t buffer_len;
+    Py_buffer buffer;
     Py_ssize_t offset = 0;
-    PyObject *obj, *result;
+    PyObject *result;
     StgDictObject *dict = PyType_stgdict(type);
     assert (dict);
 
-    if (!PyArg_ParseTuple(args, "O|n:from_buffer", &obj, &offset))
-        return NULL;
-
-    if (-1 == PyObject_AsReadBuffer(obj, (const void**)&buffer, &buffer_len))
+    if (!PyArg_ParseTuple(args, "y*|n:from_buffer", &buffer, &offset))
         return NULL;
 
     if (offset < 0) {
         PyErr_SetString(PyExc_ValueError,
                         "offset cannot be negative");
+        PyBuffer_Release(&buffer);
         return NULL;
     }
 
-    if (dict->size > buffer_len - offset) {
+    if (dict->size > buffer.len - offset) {
         PyErr_Format(PyExc_ValueError,
                      "Buffer size too small (%zd instead of at least %zd bytes)",
-                     buffer_len, dict->size + offset);
+                     buffer.len, dict->size + offset);
+        PyBuffer_Release(&buffer);
         return NULL;
     }
 
     result = GenericPyCData_new((PyTypeObject *)type, NULL, NULL);
-    if (result == NULL)
-        return NULL;
-    memcpy(((CDataObject *)result)->b_ptr,
-           (char *)buffer+offset, dict->size);
+    if (result != NULL) {
+        memcpy(((CDataObject *)result)->b_ptr,
+               (char *)buffer.buf + offset, dict->size);
+    }
+    PyBuffer_Release(&buffer);
     return result;
 }
 
diff --git a/Modules/_io/bytesio.c b/Modules/_io/bytesio.c
index 56ad788d3f..801ddcdc88 100644
--- a/Modules/_io/bytesio.c
+++ b/Modules/_io/bytesio.c
@@ -553,17 +553,18 @@ PyDoc_STRVAR(readinto_doc,
 "is set not to block as has no data to read.");
 
 static PyObject *
-bytesio_readinto(bytesio *self, PyObject *buffer)
+bytesio_readinto(bytesio *self, PyObject *arg)
 {
-    void *raw_buffer;
+    Py_buffer buffer;
     Py_ssize_t len, n;
 
     CHECK_CLOSED(self, NULL);
 
-    if (PyObject_AsWriteBuffer(buffer, &raw_buffer, &len) == -1)
+    if (!PyArg_Parse(arg, "w*", &buffer))
         return NULL;
 
     /* adjust invalid sizes */
+    len = buffer.len;
     n = self->string_size - self->pos;
     if (len > n) {
         len = n;
@@ -571,10 +572,11 @@ bytesio_readinto(bytesio *self, PyObject *buffer)
             len = 0;
     }
 
-    memcpy(raw_buffer, self->buf + self->pos, len);
+    memcpy(buffer.buf, self->buf + self->pos, len);
     assert(self->pos + len < PY_SSIZE_T_MAX);
     assert(len >= 0);
     self->pos += len;
+    PyBuffer_Release(&buffer);
 
     return PyLong_FromSsize_t(len);
 }
diff --git a/Modules/_sqlite/connection.c b/Modules/_sqlite/connection.c
index 535464dbf1..2e8cab5554 100644
--- a/Modules/_sqlite/connection.c
+++ b/Modules/_sqlite/connection.c
@@ -522,19 +522,20 @@ _pysqlite_set_result(sqlite3_context* context, PyObject* py_val)
             return -1;
         sqlite3_result_text(context, str, -1, SQLITE_TRANSIENT);
     } else if (PyObject_CheckBuffer(py_val)) {
-        const char* buffer;
-        Py_ssize_t buflen;
-        if (PyObject_AsCharBuffer(py_val, &buffer, &buflen) != 0) {
+        Py_buffer view;
+        if (PyObject_GetBuffer(py_val, &view, PyBUF_SIMPLE) != 0) {
             PyErr_SetString(PyExc_ValueError,
                             "could not convert BLOB to buffer");
             return -1;
         }
-        if (buflen > INT_MAX) {
+        if (view.len > INT_MAX) {
             PyErr_SetString(PyExc_OverflowError,
                             "BLOB longer than INT_MAX bytes");
+            PyBuffer_Release(&view);
             return -1;
         }
-        sqlite3_result_blob(context, buffer, (int)buflen, SQLITE_TRANSIENT);
+        sqlite3_result_blob(context, view.buf, (int)view.len, SQLITE_TRANSIENT);
+        PyBuffer_Release(&view);
     } else {
         return -1;
     }
diff --git a/Modules/_sqlite/statement.c b/Modules/_sqlite/statement.c
index 34babfd750..e87063341d 100644
--- a/Modules/_sqlite/statement.c
+++ b/Modules/_sqlite/statement.c
@@ -94,7 +94,6 @@ int pysqlite_statement_create(pysqlite_Statement* self, pysqlite_Connection* con
 int pysqlite_statement_bind_parameter(pysqlite_Statement* self, int pos, PyObject* parameter)
 {
     int rc = SQLITE_OK;
-    const char* buffer;
     char* string;
     Py_ssize_t buflen;
     parameter_type paramtype;
@@ -145,18 +144,22 @@ int pysqlite_statement_bind_parameter(pysqlite_Statement* self, int pos, PyObjec
             }
             rc = sqlite3_bind_text(self->st, pos, string, (int)buflen, SQLITE_TRANSIENT);
             break;
-        case TYPE_BUFFER:
-            if (PyObject_AsCharBuffer(parameter, &buffer, &buflen) != 0) {
+        case TYPE_BUFFER: {
+            Py_buffer view;
+            if (PyObject_GetBuffer(parameter, &view, PyBUF_SIMPLE) != 0) {
                 PyErr_SetString(PyExc_ValueError, "could not convert BLOB to buffer");
                 return -1;
             }
-            if (buflen > INT_MAX) {
+            if (view.len > INT_MAX) {
                 PyErr_SetString(PyExc_OverflowError,
                                 "BLOB longer than INT_MAX bytes");
+                PyBuffer_Release(&view);
                 return -1;
             }
-            rc = sqlite3_bind_blob(self->st, pos, buffer, buflen, SQLITE_TRANSIENT);
+            rc = sqlite3_bind_blob(self->st, pos, view.buf, (int)view.len, SQLITE_TRANSIENT);
+            PyBuffer_Release(&view);
             break;
+        }
         case TYPE_UNKNOWN:
             rc = -1;
     }
diff --git a/Modules/_struct.c b/Modules/_struct.c
index 06f0d3a77e..068c5d1e1d 100644
--- a/Modules/_struct.c
+++ b/Modules/_struct.c
@@ -1842,8 +1842,8 @@ static PyObject *
 s_pack_into(PyObject *self, PyObject *args)
 {
     PyStructObject *soself;
-    char *buffer;
-    Py_ssize_t buffer_len, offset;
+    Py_buffer buffer;
+    Py_ssize_t offset;
 
     /* Validate arguments.  +1 is for the first arg as buffer. */
     soself = (PyStructObject *)self;
@@ -1868,34 +1868,37 @@ s_pack_into(PyObject *self, PyObject *args)
     }
 
     /* Extract a writable memory buffer from the first argument */
-    if ( PyObject_AsWriteBuffer(PyTuple_GET_ITEM(args, 0),
-                                                            (void**)&buffer, &buffer_len) == -1 ) {
+    if (!PyArg_Parse(PyTuple_GET_ITEM(args, 0), "w*", &buffer))
         return NULL;
-    }
-    assert( buffer_len >= 0 );
+    assert(buffer.len >= 0);
 
     /* Extract the offset from the first argument */
     offset = PyNumber_AsSsize_t(PyTuple_GET_ITEM(args, 1), PyExc_IndexError);
-    if (offset == -1 && PyErr_Occurred())
+    if (offset == -1 && PyErr_Occurred()) {
+        PyBuffer_Release(&buffer);
         return NULL;
+    }
 
     /* Support negative offsets. */
     if (offset < 0)
-        offset += buffer_len;
+        offset += buffer.len;
 
     /* Check boundaries */
-    if (offset < 0 || (buffer_len - offset) < soself->s_size) {
+    if (offset < 0 || (buffer.len - offset) < soself->s_size) {
         PyErr_Format(StructError,
                      "pack_into requires a buffer of at least %zd bytes",
                      soself->s_size);
+        PyBuffer_Release(&buffer);
         return NULL;
     }
 
     /* Call the guts */
-    if ( s_pack_internal(soself, args, 2, buffer + offset) != 0 ) {
+    if (s_pack_internal(soself, args, 2, (char*)buffer.buf + offset) != 0) {
+        PyBuffer_Release(&buffer);
         return NULL;
     }
 
+    PyBuffer_Release(&buffer);
     Py_RETURN_NONE;
 }
 
diff --git a/Objects/abstract.c b/Objects/abstract.c
index d7dde91519..483f4da474 100644
--- a/Objects/abstract.c
+++ b/Objects/abstract.c
@@ -250,27 +250,7 @@ PyObject_AsCharBuffer(PyObject *obj,
                       const char **buffer,
                       Py_ssize_t *buffer_len)
 {
-    PyBufferProcs *pb;
-    Py_buffer view;
-
-    if (obj == NULL || buffer == NULL || buffer_len == NULL) {
-        null_error();
-        return -1;
-    }
-    pb = obj->ob_type->tp_as_buffer;
-    if (pb == NULL || pb->bf_getbuffer == NULL) {
-        PyErr_SetString(PyExc_TypeError,
-                        "expected a bytes-like object");
-        return -1;
-    }
-    if ((*pb->bf_getbuffer)(obj, &view, PyBUF_SIMPLE)) return -1;
-
-    *buffer = view.buf;
-    *buffer_len = view.len;
-    if (pb->bf_releasebuffer != NULL)
-        (*pb->bf_releasebuffer)(obj, &view);
-    Py_XDECREF(view.obj);
-    return 0;
+    return PyObject_AsReadBuffer(obj, (const void **)buffer, buffer_len);
 }
 
 int
@@ -294,28 +274,18 @@ int PyObject_AsReadBuffer(PyObject *obj,
                           const void **buffer,
                           Py_ssize_t *buffer_len)
 {
-    PyBufferProcs *pb;
     Py_buffer view;
 
     if (obj == NULL || buffer == NULL || buffer_len == NULL) {
         null_error();
         return -1;
     }
-    pb = obj->ob_type->tp_as_buffer;
-    if (pb == NULL ||
-        pb->bf_getbuffer == NULL) {
-        PyErr_SetString(PyExc_TypeError,
-                        "expected a bytes-like object");
+    if (PyObject_GetBuffer(obj, &view, PyBUF_SIMPLE) != 0)
         return -1;
-    }
-
-    if ((*pb->bf_getbuffer)(obj, &view, PyBUF_SIMPLE)) return -1;
 
     *buffer = view.buf;
     *buffer_len = view.len;
-    if (pb->bf_releasebuffer != NULL)
-        (*pb->bf_releasebuffer)(obj, &view);
-    Py_XDECREF(view.obj);
+    PyBuffer_Release(&view);
     return 0;
 }
 
@@ -341,9 +311,7 @@ int PyObject_AsWriteBuffer(PyObject *obj,
 
     *buffer = view.buf;
     *buffer_len = view.len;
-    if (pb->bf_releasebuffer != NULL)
-        (*pb->bf_releasebuffer)(obj, &view);
-    Py_XDECREF(view.obj);
+    PyBuffer_Release(&view);
     return 0;
 }
 
@@ -352,13 +320,15 @@ int PyObject_AsWriteBuffer(PyObject *obj,
 int
 PyObject_GetBuffer(PyObject *obj, Py_buffer *view, int flags)
 {
-    if (!PyObject_CheckBuffer(obj)) {
+    PyBufferProcs *pb = obj->ob_type->tp_as_buffer;
+
+    if (pb == NULL || pb->bf_getbuffer == NULL) {
         PyErr_Format(PyExc_TypeError,
                      "a bytes-like object is required, not '%.100s'",
                      Py_TYPE(obj)->tp_name);
         return -1;
     }
-    return (*(obj->ob_type->tp_as_buffer->bf_getbuffer))(obj, view, flags);
+    return (*pb->bf_getbuffer)(obj, view, flags);
 }
 
 static int
@@ -676,10 +646,14 @@ void
 PyBuffer_Release(Py_buffer *view)
 {
     PyObject *obj = view->obj;
-    if (obj && Py_TYPE(obj)->tp_as_buffer && Py_TYPE(obj)->tp_as_buffer->bf_releasebuffer)
-        Py_TYPE(obj)->tp_as_buffer->bf_releasebuffer(obj, view);
-    Py_XDECREF(obj);
+    PyBufferProcs *pb;
+    if (obj == NULL)
+        return;
+    pb = Py_TYPE(obj)->tp_as_buffer;
+    if (pb && pb->bf_releasebuffer)
+        pb->bf_releasebuffer(obj, view);
     view->obj = NULL;
+    Py_DECREF(obj);
 }
 
 PyObject *
@@ -1288,8 +1262,7 @@ PyNumber_Long(PyObject *o)
 {
     PyNumberMethods *m;
     PyObject *trunc_func;
-    const char *buffer;
-    Py_ssize_t buffer_len;
+    Py_buffer view;
     _Py_IDENTIFIER(__trunc__);
 
     if (o == NULL)
@@ -1327,21 +1300,22 @@ PyNumber_Long(PyObject *o)
     if (PyErr_Occurred())
         return NULL;
 
-    if (PyBytes_Check(o))
+    if (PyUnicode_Check(o))
+        /* The below check is done in PyLong_FromUnicode(). */
+        return PyLong_FromUnicodeObject(o, 10);
+
+    if (PyObject_GetBuffer(o, &view, PyBUF_SIMPLE) == 0) {
         /* need to do extra error checking that PyLong_FromString()
          * doesn't do.  In particular int('9\x005') must raise an
          * exception, not truncate at the null.
          */
-        return _PyLong_FromBytes(PyBytes_AS_STRING(o),
-                                 PyBytes_GET_SIZE(o), 10);
-    if (PyUnicode_Check(o))
-        /* The above check is done in PyLong_FromUnicode(). */
-        return PyLong_FromUnicodeObject(o, 10);
-    if (!PyObject_AsCharBuffer(o, &buffer, &buffer_len))
-        return _PyLong_FromBytes(buffer, buffer_len, 10);
+        PyObject *result = _PyLong_FromBytes(view.buf, view.len, 10);
+        PyBuffer_Release(&view);
+        return result;
+    }
 
-    return type_error("int() argument must be a string or a "
-                      "number, not '%.200s'", o);
+    return type_error("int() argument must be a string, a bytes-like object "
+                      "or a number, not '%.200s'", o);
 }
 
 PyObject *
diff --git a/Objects/bytearrayobject.c b/Objects/bytearrayobject.c
index b9a87d6a31..ce22f4bb49 100644
--- a/Objects/bytearrayobject.c
+++ b/Objects/bytearrayobject.c
@@ -80,24 +80,6 @@ bytearray_releasebuffer(PyByteArrayObject *obj, Py_buffer *view)
     obj->ob_exports--;
 }
 
-static Py_ssize_t
-_getbuffer(PyObject *obj, Py_buffer *view)
-{
-    PyBufferProcs *buffer = Py_TYPE(obj)->tp_as_buffer;
-
-    if (buffer == NULL || buffer->bf_getbuffer == NULL)
-    {
-        PyErr_Format(PyExc_TypeError,
-                     "a bytes-like object is required, not '%.100s'",
-                     Py_TYPE(obj)->tp_name);
-        return -1;
-    }
-
-    if (buffer->bf_getbuffer(obj, view, PyBUF_SIMPLE) < 0)
-            return -1;
-    return view->len;
-}
-
 static int
 _canresize(PyByteArrayObject *self)
 {
@@ -268,8 +250,8 @@ PyByteArray_Concat(PyObject *a, PyObject *b)
 
     va.len = -1;
     vb.len = -1;
-    if (_getbuffer(a, &va) < 0  ||
-        _getbuffer(b, &vb) < 0) {
+    if (PyObject_GetBuffer(a, &va, PyBUF_SIMPLE) != 0 ||
+        PyObject_GetBuffer(b, &vb, PyBUF_SIMPLE) != 0) {
             PyErr_Format(PyExc_TypeError, "can't concat %.100s to %.100s",
                          Py_TYPE(a)->tp_name, Py_TYPE(b)->tp_name);
             goto done;
@@ -335,7 +317,7 @@ bytearray_iconcat(PyByteArrayObject *self, PyObject *other)
     Py_ssize_t size;
     Py_buffer vo;
 
-    if (_getbuffer(other, &vo) < 0) {
+    if (PyObject_GetBuffer(other, &vo, PyBUF_SIMPLE) != 0) {
         PyErr_Format(PyExc_TypeError, "can't concat %.100s to %.100s",
                      Py_TYPE(other)->tp_name, Py_TYPE(self)->tp_name);
         return NULL;
@@ -595,14 +577,14 @@ bytearray_setslice(PyByteArrayObject *self, Py_ssize_t lo, Py_ssize_t hi,
         needed = 0;
     }
     else {
-            if (_getbuffer(values, &vbytes) < 0) {
-                    PyErr_Format(PyExc_TypeError,
-                                 "can't set bytearray slice from %.100s",
-                                 Py_TYPE(values)->tp_name);
-                    return -1;
-            }
-            needed = vbytes.len;
-            bytes = vbytes.buf;
+        if (PyObject_GetBuffer(values, &vbytes, PyBUF_SIMPLE) != 0) {
+            PyErr_Format(PyExc_TypeError,
+                         "can't set bytearray slice from %.100s",
+                         Py_TYPE(values)->tp_name);
+            return -1;
+        }
+        needed = vbytes.len;
+        bytes = vbytes.buf;
     }
 
     if (lo < 0)
@@ -1047,18 +1029,18 @@ bytearray_richcompare(PyObject *self, PyObject *other, int op)
         Py_RETURN_NOTIMPLEMENTED;
     }
 
-    self_size = _getbuffer(self, &self_bytes);
-    if (self_size < 0) {
+    if (PyObject_GetBuffer(self, &self_bytes, PyBUF_SIMPLE) != 0) {
         PyErr_Clear();
         Py_RETURN_NOTIMPLEMENTED;
     }
+    self_size = self_bytes.len;
 
-    other_size = _getbuffer(other, &other_bytes);
-    if (other_size < 0) {
+    if (PyObject_GetBuffer(other, &other_bytes, PyBUF_SIMPLE) != 0) {
         PyErr_Clear();
         PyBuffer_Release(&self_bytes);
         Py_RETURN_NOTIMPLEMENTED;
     }
+    other_size = other_bytes.len;
 
     if (self_size != other_size && (op == Py_EQ || op == Py_NE)) {
         /* Shortcut: if the lengths differ, the objects differ */
@@ -1170,7 +1152,7 @@ bytearray_find_internal(PyByteArrayObject *self, PyObject *args, int dir)
         return -2;
 
     if (subobj) {
-        if (_getbuffer(subobj, &subbuf) < 0)
+        if (PyObject_GetBuffer(subobj, &subbuf, PyBUF_SIMPLE) != 0)
             return -2;
 
         sub = subbuf.buf;
@@ -1238,7 +1220,7 @@ bytearray_count(PyByteArrayObject *self, PyObject *args)
         return NULL;
 
     if (sub_obj) {
-        if (_getbuffer(sub_obj, &vsub) < 0)
+        if (PyObject_GetBuffer(sub_obj, &vsub, PyBUF_SIMPLE) != 0)
             return NULL;
 
         sub = vsub.buf;
@@ -1397,7 +1379,7 @@ bytearray_contains(PyObject *self, PyObject *arg)
         Py_buffer varg;
         Py_ssize_t pos;
         PyErr_Clear();
-        if (_getbuffer(arg, &varg) < 0)
+        if (PyObject_GetBuffer(arg, &varg, PyBUF_SIMPLE) != 0)
             return -1;
         pos = stringlib_find(PyByteArray_AS_STRING(self), Py_SIZE(self),
                              varg.buf, varg.len, 0);
@@ -1428,7 +1410,7 @@ _bytearray_tailmatch(PyByteArrayObject *self, PyObject *substr, Py_ssize_t start
 
     str = PyByteArray_AS_STRING(self);
 
-    if (_getbuffer(substr, &vsubstr) < 0)
+    if (PyObject_GetBuffer(substr, &vsubstr, PyBUF_SIMPLE) != 0)
         return -1;
 
     ADJUST_INDICES(start, end, len);
@@ -1621,7 +1603,7 @@ bytearray_translate_impl(PyByteArrayObject *self, PyObject *table, int group_rig
     if (table == Py_None) {
         table_chars = NULL;
         table = NULL;
-    } else if (_getbuffer(table, &vtable) < 0) {
+    } else if (PyObject_GetBuffer(table, &vtable, PyBUF_SIMPLE) != 0) {
         return NULL;
     } else {
         if (vtable.len != 256) {
@@ -1634,7 +1616,7 @@ bytearray_translate_impl(PyByteArrayObject *self, PyObject *table, int group_rig
     }
 
     if (deletechars != NULL) {
-        if (_getbuffer(deletechars, &vdel) < 0) {
+        if (PyObject_GetBuffer(deletechars, &vdel, PyBUF_SIMPLE) != 0) {
             if (table != NULL)
                 PyBuffer_Release(&vtable);
             return NULL;
@@ -1699,8 +1681,8 @@ done:
 @staticmethod
 bytearray.maketrans
 
-    frm: object
-    to: object
+    frm: Py_buffer
+    to: Py_buffer
     /
 
 Return a translation table useable for the bytes or bytearray translate method.
@@ -1726,28 +1708,35 @@ PyDoc_STRVAR(bytearray_maketrans__doc__,
     {"maketrans", (PyCFunction)bytearray_maketrans, METH_VARARGS|METH_STATIC, bytearray_maketrans__doc__},
 
 static PyObject *
-bytearray_maketrans_impl(PyObject *frm, PyObject *to);
+bytearray_maketrans_impl(Py_buffer *frm, Py_buffer *to);
 
 static PyObject *
 bytearray_maketrans(void *null, PyObject *args)
 {
     PyObject *return_value = NULL;
-    PyObject *frm;
-    PyObject *to;
+    Py_buffer frm = {NULL, NULL};
+    Py_buffer to = {NULL, NULL};
 
-    if (!PyArg_UnpackTuple(args, "maketrans",
-        2, 2,
+    if (!PyArg_ParseTuple(args,
+        "y*y*:maketrans",
         &frm, &to))
         goto exit;
-    return_value = bytearray_maketrans_impl(frm, to);
+    return_value = bytearray_maketrans_impl(&frm, &to);
 
 exit:
+    /* Cleanup for frm */
+    if (frm.obj)
+       PyBuffer_Release(&frm);
+    /* Cleanup for to */
+    if (to.obj)
+       PyBuffer_Release(&to);
+
     return return_value;
 }
 
 static PyObject *
-bytearray_maketrans_impl(PyObject *frm, PyObject *to)
-/*[clinic end generated code: output=307752019d9b25b5 input=ea9bdc6b328c15e2]*/
+bytearray_maketrans_impl(Py_buffer *frm, Py_buffer *to)
+/*[clinic end generated code: output=d332622814c26f4b input=5925a81d2fbbf151]*/
 {
     return _Py_bytes_maketrans(frm, to);
 }
@@ -2243,8 +2232,8 @@ replace(PyByteArrayObject *self,
 /*[clinic input]
 bytearray.replace
 
-    old: object
-    new: object
+    old: Py_buffer
+    new: Py_buffer
     count: Py_ssize_t = -1
         Maximum number of occurrences to replace.
         -1 (the default value) means replace all occurrences.
@@ -2273,47 +2262,40 @@ PyDoc_STRVAR(bytearray_replace__doc__,
     {"replace", (PyCFunction)bytearray_replace, METH_VARARGS, bytearray_replace__doc__},
 
 static PyObject *
-bytearray_replace_impl(PyByteArrayObject *self, PyObject *old, PyObject *new, Py_ssize_t count);
+bytearray_replace_impl(PyByteArrayObject *self, Py_buffer *old, Py_buffer *new, Py_ssize_t count);
 
 static PyObject *
 bytearray_replace(PyByteArrayObject *self, PyObject *args)
 {
     PyObject *return_value = NULL;
-    PyObject *old;
-    PyObject *new;
+    Py_buffer old = {NULL, NULL};
+    Py_buffer new = {NULL, NULL};
     Py_ssize_t count = -1;
 
     if (!PyArg_ParseTuple(args,
-        "OO|n:replace",
+        "y*y*|n:replace",
         &old, &new, &count))
         goto exit;
-    return_value = bytearray_replace_impl(self, old, new, count);
+    return_value = bytearray_replace_impl(self, &old, &new, count);
 
 exit:
+    /* Cleanup for old */
+    if (old.obj)
+       PyBuffer_Release(&old);
+    /* Cleanup for new */
+    if (new.obj)
+       PyBuffer_Release(&new);
+
     return return_value;
 }
 
 static PyObject *
-bytearray_replace_impl(PyByteArrayObject *self, PyObject *old, PyObject *new, Py_ssize_t count)
-/*[clinic end generated code: output=4d2e3c9130da0f96 input=9aaaa123608dfc1f]*/
+bytearray_replace_impl(PyByteArrayObject *self, Py_buffer *old, Py_buffer *new, Py_ssize_t count)
+/*[clinic end generated code: output=9997fbbd5bac4883 input=aa379d988637c7fb]*/
 {
-    PyObject *res;
-    Py_buffer vold, vnew;
-
-    if (_getbuffer(old, &vold) < 0)
-        return NULL;
-    if (_getbuffer(new, &vnew) < 0) {
-        PyBuffer_Release(&vold);
-        return NULL;
-    }
-
-    res = (PyObject *)replace((PyByteArrayObject *) self,
-                              vold.buf, vold.len,
-                              vnew.buf, vnew.len, count);
-
-    PyBuffer_Release(&vold);
-    PyBuffer_Release(&vnew);
-    return res;
+    return (PyObject *)replace((PyByteArrayObject *) self,
+                               old->buf, old->len,
+                               new->buf, new->len, count);
 }
 
 /*[clinic input]
@@ -2383,7 +2365,7 @@ bytearray_split_impl(PyByteArrayObject *self, PyObject *sep, Py_ssize_t maxsplit
     if (sep == Py_None)
         return stringlib_split_whitespace((PyObject*) self, s, len, maxsplit);
 
-    if (_getbuffer(sep, &vsub) < 0)
+    if (PyObject_GetBuffer(sep, &vsub, PyBUF_SIMPLE) != 0)
         return NULL;
     sub = vsub.buf;
     n = vsub.len;
@@ -2566,7 +2548,7 @@ bytearray_rsplit_impl(PyByteArrayObject *self, PyObject *sep, Py_ssize_t maxspli
     if (sep == Py_None)
         return stringlib_rsplit_whitespace((PyObject*) self, s, len, maxsplit);
 
-    if (_getbuffer(sep, &vsub) < 0)
+    if (PyObject_GetBuffer(sep, &vsub, PyBUF_SIMPLE) != 0)
         return NULL;
     sub = vsub.buf;
     n = vsub.len;
@@ -3088,7 +3070,7 @@ bytearray_strip_impl(PyByteArrayObject *self, PyObject *bytes)
         byteslen = 6;
     }
     else {
-        if (_getbuffer(bytes, &vbytes) < 0)
+        if (PyObject_GetBuffer(bytes, &vbytes, PyBUF_SIMPLE) != 0)
             return NULL;
         bytesptr = (char *) vbytes.buf;
         byteslen = vbytes.len;
@@ -3159,7 +3141,7 @@ bytearray_lstrip_impl(PyByteArrayObject *self, PyObject *bytes)
         byteslen = 6;
     }
     else {
-        if (_getbuffer(bytes, &vbytes) < 0)
+        if (PyObject_GetBuffer(bytes, &vbytes, PyBUF_SIMPLE) != 0)
             return NULL;
         bytesptr = (char *) vbytes.buf;
         byteslen = vbytes.len;
@@ -3227,7 +3209,7 @@ bytearray_rstrip_impl(PyByteArrayObject *self, PyObject *bytes)
         byteslen = 6;
     }
     else {
-        if (_getbuffer(bytes, &vbytes) < 0)
+        if (PyObject_GetBuffer(bytes, &vbytes, PyBUF_SIMPLE) != 0)
             return NULL;
         bytesptr = (char *) vbytes.buf;
         byteslen = vbytes.len;
diff --git a/Objects/bytes_methods.c b/Objects/bytes_methods.c
index 1cf20c97d3..a29991584a 100644
--- a/Objects/bytes_methods.c
+++ b/Objects/bytes_methods.c
@@ -363,59 +363,27 @@ for use in the bytes or bytearray translate method where each byte\n\
 in frm is mapped to the byte at the same position in to.\n\
 The bytes objects frm and to must be of the same length.");
 
-static Py_ssize_t
-_getbuffer(PyObject *obj, Py_buffer *view)
-{
-    PyBufferProcs *buffer = Py_TYPE(obj)->tp_as_buffer;
-
-    if (buffer == NULL || buffer->bf_getbuffer == NULL)
-    {
-        PyErr_Format(PyExc_TypeError,
-                     "a bytes-like object is required, not '%.100s'",
-                     Py_TYPE(obj)->tp_name);
-        return -1;
-    }
-
-    if (buffer->bf_getbuffer(obj, view, PyBUF_SIMPLE) < 0)
-        return -1;
-    return view->len;
-}
-
 PyObject *
-_Py_bytes_maketrans(PyObject *frm, PyObject *to)
+_Py_bytes_maketrans(Py_buffer *frm, Py_buffer *to)
 {
     PyObject *res = NULL;
-    Py_buffer bfrm, bto;
     Py_ssize_t i;
     char *p;
 
-    bfrm.len = -1;
-    bto.len = -1;
-
-    if (_getbuffer(frm, &bfrm) < 0)
-        return NULL;
-    if (_getbuffer(to, &bto) < 0)
-        goto done;
-    if (bfrm.len != bto.len) {
+    if (frm->len != to->len) {
         PyErr_Format(PyExc_ValueError,
                      "maketrans arguments must have same length");
-        goto done;
+        return NULL;
     }
     res = PyBytes_FromStringAndSize(NULL, 256);
-    if (!res) {
-        goto done;
-    }
+    if (!res)
+        return NULL;
     p = PyBytes_AS_STRING(res);
     for (i = 0; i < 256; i++)
         p[i] = (char) i;
-    for (i = 0; i < bfrm.len; i++) {
-        p[((unsigned char *)bfrm.buf)[i]] = ((char *)bto.buf)[i];
+    for (i = 0; i < frm->len; i++) {
+        p[((unsigned char *)frm->buf)[i]] = ((char *)to->buf)[i];
     }
 
-done:
-    if (bfrm.len != -1)
-        PyBuffer_Release(&bfrm);
-    if (bto.len != -1)
-        PyBuffer_Release(&bto);
     return res;
 }
diff --git a/Objects/bytesobject.c b/Objects/bytesobject.c
index d4f7d01197..b2fbc92622 100644
--- a/Objects/bytesobject.c
+++ b/Objects/bytesobject.c
@@ -12,33 +12,6 @@ class bytes "PyBytesObject*" "&PyBytes_Type"
 [clinic start generated code]*/
 /*[clinic end generated code: output=da39a3ee5e6b4b0d input=1a1d9102afc1b00c]*/
 
-static Py_ssize_t
-_getbuffer(PyObject *obj, Py_buffer *view)
-{
-    PyBufferProcs *bufferprocs;
-    if (PyBytes_CheckExact(obj)) {
-        /* Fast path, e.g. for .join() of many bytes objects */
-        Py_INCREF(obj);
-        view->obj = obj;
-        view->buf = PyBytes_AS_STRING(obj);
-        view->len = PyBytes_GET_SIZE(obj);
-        return view->len;
-    }
-
-    bufferprocs = Py_TYPE(obj)->tp_as_buffer;
-    if (bufferprocs == NULL || bufferprocs->bf_getbuffer == NULL)
-    {
-        PyErr_Format(PyExc_TypeError,
-                     "a bytes-like object is required, not '%.100s'",
-                     Py_TYPE(obj)->tp_name);
-        return -1;
-    }
-
-    if (bufferprocs->bf_getbuffer(obj, view, PyBUF_SIMPLE) < 0)
-        return -1;
-    return view->len;
-}
-
 #ifdef COUNT_ALLOCS
 Py_ssize_t null_strings, one_strings;
 #endif
@@ -1349,8 +1322,8 @@ bytes_concat(PyObject *a, PyObject *b)
 
     va.len = -1;
     vb.len = -1;
-    if (_getbuffer(a, &va) < 0  ||
-        _getbuffer(b, &vb) < 0) {
+    if (PyObject_GetBuffer(a, &va, PyBUF_SIMPLE) != 0 ||
+        PyObject_GetBuffer(b, &vb, PyBUF_SIMPLE) != 0) {
         PyErr_Format(PyExc_TypeError, "can't concat %.100s to %.100s",
                      Py_TYPE(a)->tp_name, Py_TYPE(b)->tp_name);
         goto done;
@@ -1448,7 +1421,7 @@ bytes_contains(PyObject *self, PyObject *arg)
         Py_buffer varg;
         Py_ssize_t pos;
         PyErr_Clear();
-        if (_getbuffer(arg, &varg) < 0)
+        if (PyObject_GetBuffer(arg, &varg, PyBUF_SIMPLE) != 0)
             return -1;
         pos = stringlib_find(PyBytes_AS_STRING(self), Py_SIZE(self),
                              varg.buf, varg.len, 0);
@@ -1737,7 +1710,7 @@ bytes_split_impl(PyBytesObject*self, PyObject *sep, Py_ssize_t maxsplit)
         maxsplit = PY_SSIZE_T_MAX;
     if (sep == Py_None)
         return stringlib_split_whitespace((PyObject*) self, s, len, maxsplit);
-    if (_getbuffer(sep, &vsub) < 0)
+    if (PyObject_GetBuffer(sep, &vsub, PyBUF_SIMPLE) != 0)
         return NULL;
     sub = vsub.buf;
     n = vsub.len;
@@ -1751,7 +1724,7 @@ bytes_split_impl(PyBytesObject*self, PyObject *sep, Py_ssize_t maxsplit)
 bytes.partition
 
     self: self(type="PyBytesObject *")
-    sep: object
+    sep: Py_buffer
     /
 
 Partition the bytes into three parts using the given separator.
@@ -1778,26 +1751,39 @@ PyDoc_STRVAR(bytes_partition__doc__,
 "object and two empty bytes objects.");
 
 #define BYTES_PARTITION_METHODDEF    \
-    {"partition", (PyCFunction)bytes_partition, METH_O, bytes_partition__doc__},
+    {"partition", (PyCFunction)bytes_partition, METH_VARARGS, bytes_partition__doc__},
 
 static PyObject *
-bytes_partition(PyBytesObject *self, PyObject *sep)
-/*[clinic end generated code: output=b41e119c873c08bc input=6c5b9dcc5a9fd62e]*/
+bytes_partition_impl(PyBytesObject *self, Py_buffer *sep);
+
+static PyObject *
+bytes_partition(PyBytesObject *self, PyObject *args)
 {
-    const char *sep_chars;
-    Py_ssize_t sep_len;
+    PyObject *return_value = NULL;
+    Py_buffer sep = {NULL, NULL};
 
-    if (PyBytes_Check(sep)) {
-        sep_chars = PyBytes_AS_STRING(sep);
-        sep_len = PyBytes_GET_SIZE(sep);
-    }
-    else if (PyObject_AsCharBuffer(sep, &sep_chars, &sep_len))
-        return NULL;
+    if (!PyArg_ParseTuple(args,
+        "y*:partition",
+        &sep))
+        goto exit;
+    return_value = bytes_partition_impl(self, &sep);
+
+exit:
+    /* Cleanup for sep */
+    if (sep.obj)
+       PyBuffer_Release(&sep);
 
+    return return_value;
+}
+
+static PyObject *
+bytes_partition_impl(PyBytesObject *self, Py_buffer *sep)
+/*[clinic end generated code: output=3006727cfbf83aa4 input=bc855dc63ca949de]*/
+{
     return stringlib_partition(
         (PyObject*) self,
         PyBytes_AS_STRING(self), PyBytes_GET_SIZE(self),
-        sep, sep_chars, sep_len
+        sep->obj, (const char *)sep->buf, sep->len
         );
 }
 
@@ -1805,7 +1791,7 @@ bytes_partition(PyBytesObject *self, PyObject *sep)
 bytes.rpartition
 
     self: self(type="PyBytesObject *")
-    sep: object
+    sep: Py_buffer
     /
 
 Partition the bytes into three parts using the given separator.
@@ -1832,26 +1818,39 @@ PyDoc_STRVAR(bytes_rpartition__doc__,
 "objects and the original bytes object.");
 
 #define BYTES_RPARTITION_METHODDEF    \
-    {"rpartition", (PyCFunction)bytes_rpartition, METH_O, bytes_rpartition__doc__},
+    {"rpartition", (PyCFunction)bytes_rpartition, METH_VARARGS, bytes_rpartition__doc__},
 
 static PyObject *
-bytes_rpartition(PyBytesObject *self, PyObject *sep)
-/*[clinic end generated code: output=3a620803657196ee input=79bc2932e78e5ce0]*/
+bytes_rpartition_impl(PyBytesObject *self, Py_buffer *sep);
+
+static PyObject *
+bytes_rpartition(PyBytesObject *self, PyObject *args)
 {
-    const char *sep_chars;
-    Py_ssize_t sep_len;
+    PyObject *return_value = NULL;
+    Py_buffer sep = {NULL, NULL};
 
-    if (PyBytes_Check(sep)) {
-        sep_chars = PyBytes_AS_STRING(sep);
-        sep_len = PyBytes_GET_SIZE(sep);
-    }
-    else if (PyObject_AsCharBuffer(sep, &sep_chars, &sep_len))
-        return NULL;
+    if (!PyArg_ParseTuple(args,
+        "y*:rpartition",
+        &sep))
+        goto exit;
+    return_value = bytes_rpartition_impl(self, &sep);
+
+exit:
+    /* Cleanup for sep */
+    if (sep.obj)
+       PyBuffer_Release(&sep);
 
+    return return_value;
+}
+
+static PyObject *
+bytes_rpartition_impl(PyBytesObject *self, Py_buffer *sep)
+/*[clinic end generated code: output=57b169dc47fa90e8 input=6588fff262a9170e]*/
+{
     return stringlib_rpartition(
         (PyObject*) self,
         PyBytes_AS_STRING(self), PyBytes_GET_SIZE(self),
-        sep, sep_chars, sep_len
+        sep->obj, (const char *)sep->buf, sep->len
         );
 }
 
@@ -1916,7 +1915,7 @@ bytes_rsplit_impl(PyBytesObject*self, PyObject *sep, Py_ssize_t maxsplit)
         maxsplit = PY_SSIZE_T_MAX;
     if (sep == Py_None)
         return stringlib_rsplit_whitespace((PyObject*) self, s, len, maxsplit);
-    if (_getbuffer(sep, &vsub) < 0)
+    if (PyObject_GetBuffer(sep, &vsub, PyBUF_SIMPLE) != 0)
         return NULL;
     sub = vsub.buf;
     n = vsub.len;
@@ -2003,7 +2002,7 @@ bytes_find_internal(PyBytesObject *self, PyObject *args, int dir)
         return -2;
 
     if (subobj) {
-        if (_getbuffer(subobj, &subbuf) < 0)
+        if (PyObject_GetBuffer(subobj, &subbuf, PyBUF_SIMPLE) != 0)
             return -2;
 
         sub = subbuf.buf;
@@ -2118,7 +2117,7 @@ do_xstrip(PyBytesObject *self, int striptype, PyObject *sepobj)
     Py_ssize_t seplen;
     Py_ssize_t i, j;
 
-    if (_getbuffer(sepobj, &vsep) < 0)
+    if (PyObject_GetBuffer(sepobj, &vsep, PyBUF_SIMPLE) != 0)
         return NULL;
     sep = vsep.buf;
     seplen = vsep.len;
@@ -2360,7 +2359,7 @@ bytes_count(PyBytesObject *self, PyObject *args)
         return NULL;
 
     if (sub_obj) {
-        if (_getbuffer(sub_obj, &vsub) < 0)
+        if (PyObject_GetBuffer(sub_obj, &vsub, PyBUF_SIMPLE) != 0)
             return NULL;
 
         sub = vsub.buf;
@@ -2450,6 +2449,8 @@ bytes_translate_impl(PyBytesObject *self, PyObject *table, int group_right_1, Py
 /*[clinic end generated code: output=f0f29a57f41df5d8 input=d8fa5519d7cc4be7]*/
 {
     char *input, *output;
+    Py_buffer table_view = {NULL, NULL};
+    Py_buffer del_table_view = {NULL, NULL};
     const char *table_chars;
     Py_ssize_t i, c, changed = 0;
     PyObject *input_obj = (PyObject*)self;
@@ -2466,12 +2467,17 @@ bytes_translate_impl(PyBytesObject *self, PyObject *table, int group_right_1, Py
         table_chars = NULL;
         tablen = 256;
     }
-    else if (PyObject_AsCharBuffer(table, &table_chars, &tablen))
-        return NULL;
+    else {
+        if (PyObject_GetBuffer(table, &table_view, PyBUF_SIMPLE) != 0)
+            return NULL;
+        table_chars = table_view.buf;
+        tablen = table_view.len;
+    }
 
     if (tablen != 256) {
         PyErr_SetString(PyExc_ValueError,
           "translation table must be 256 characters long");
+        PyBuffer_Release(&table_view);
         return NULL;
     }
 
@@ -2480,8 +2486,14 @@ bytes_translate_impl(PyBytesObject *self, PyObject *table, int group_right_1, Py
             del_table_chars = PyBytes_AS_STRING(deletechars);
             dellen = PyBytes_GET_SIZE(deletechars);
         }
-        else if (PyObject_AsCharBuffer(deletechars, &del_table_chars, &dellen))
-            return NULL;
+        else {
+            if (PyObject_GetBuffer(deletechars, &del_table_view, PyBUF_SIMPLE) != 0) {
+                PyBuffer_Release(&table_view);
+                return NULL;
+            }
+            del_table_chars = del_table_view.buf;
+            dellen = del_table_view.len;
+        }
     }
     else {
         del_table_chars = NULL;
@@ -2490,8 +2502,11 @@ bytes_translate_impl(PyBytesObject *self, PyObject *table, int group_right_1, Py
 
     inlen = PyBytes_GET_SIZE(input_obj);
     result = PyBytes_FromStringAndSize((char *)NULL, inlen);
-    if (result == NULL)
+    if (result == NULL) {
+        PyBuffer_Release(&del_table_view);
+        PyBuffer_Release(&table_view);
         return NULL;
+    }
     output_start = output = PyBytes_AsString(result);
     input = PyBytes_AS_STRING(input_obj);
 
@@ -2502,11 +2517,14 @@ bytes_translate_impl(PyBytesObject *self, PyObject *table, int group_right_1, Py
             if (Py_CHARMASK((*output++ = table_chars[c])) != c)
                 changed = 1;
         }
-        if (changed || !PyBytes_CheckExact(input_obj))
-            return result;
-        Py_DECREF(result);
-        Py_INCREF(input_obj);
-        return input_obj;
+        if (!changed && PyBytes_CheckExact(input_obj)) {
+            Py_INCREF(input_obj);
+            Py_DECREF(result);
+            result = input_obj;
+        }
+        PyBuffer_Release(&del_table_view);
+        PyBuffer_Release(&table_view);
+        return result;
     }
 
     if (table_chars == NULL) {
@@ -2516,9 +2534,11 @@ bytes_translate_impl(PyBytesObject *self, PyObject *table, int group_right_1, Py
         for (i = 0; i < 256; i++)
             trans_table[i] = Py_CHARMASK(table_chars[i]);
     }
+    PyBuffer_Release(&table_view);
 
     for (i = 0; i < dellen; i++)
         trans_table[(int) Py_CHARMASK(del_table_chars[i])] = -1;
+    PyBuffer_Release(&del_table_view);
 
     for (i = inlen; --i >= 0; ) {
         c = Py_CHARMASK(*input++);
@@ -2544,8 +2564,8 @@ bytes_translate_impl(PyBytesObject *self, PyObject *table, int group_right_1, Py
 @staticmethod
 bytes.maketrans
 
-    frm: object
-    to: object
+    frm: Py_buffer
+    to: Py_buffer
     /
 
 Return a translation table useable for the bytes or bytearray translate method.
@@ -2571,28 +2591,35 @@ PyDoc_STRVAR(bytes_maketrans__doc__,
     {"maketrans", (PyCFunction)bytes_maketrans, METH_VARARGS|METH_STATIC, bytes_maketrans__doc__},
 
 static PyObject *
-bytes_maketrans_impl(PyObject *frm, PyObject *to);
+bytes_maketrans_impl(Py_buffer *frm, Py_buffer *to);
 
 static PyObject *
 bytes_maketrans(void *null, PyObject *args)
 {
     PyObject *return_value = NULL;
-    PyObject *frm;
-    PyObject *to;
+    Py_buffer frm = {NULL, NULL};
+    Py_buffer to = {NULL, NULL};
 
-    if (!PyArg_UnpackTuple(args, "maketrans",
-        2, 2,
+    if (!PyArg_ParseTuple(args,
+        "y*y*:maketrans",
         &frm, &to))
         goto exit;
-    return_value = bytes_maketrans_impl(frm, to);
+    return_value = bytes_maketrans_impl(&frm, &to);
 
 exit:
+    /* Cleanup for frm */
+    if (frm.obj)
+       PyBuffer_Release(&frm);
+    /* Cleanup for to */
+    if (to.obj)
+       PyBuffer_Release(&to);
+
     return return_value;
 }
 
 static PyObject *
-bytes_maketrans_impl(PyObject *frm, PyObject *to)
-/*[clinic end generated code: output=89a3c3556975e466 input=d204f680f85da382]*/
+bytes_maketrans_impl(Py_buffer *frm, Py_buffer *to)
+/*[clinic end generated code: output=7df47390c476ac60 input=de7a8fc5632bb8f1]*/
 {
     return _Py_bytes_maketrans(frm, to);
 }
@@ -3093,8 +3120,8 @@ replace(PyBytesObject *self,
 /*[clinic input]
 bytes.replace
 
-    old: object
-    new: object
+    old: Py_buffer
+    new: Py_buffer
     count: Py_ssize_t = -1
         Maximum number of occurrences to replace.
         -1 (the default value) means replace all occurrences.
@@ -3123,50 +3150,40 @@ PyDoc_STRVAR(bytes_replace__doc__,
     {"replace", (PyCFunction)bytes_replace, METH_VARARGS, bytes_replace__doc__},
 
 static PyObject *
-bytes_replace_impl(PyBytesObject*self, PyObject *old, PyObject *new, Py_ssize_t count);
+bytes_replace_impl(PyBytesObject*self, Py_buffer *old, Py_buffer *new, Py_ssize_t count);
 
 static PyObject *
 bytes_replace(PyBytesObject*self, PyObject *args)
 {
     PyObject *return_value = NULL;
-    PyObject *old;
-    PyObject *new;
+    Py_buffer old = {NULL, NULL};
+    Py_buffer new = {NULL, NULL};
     Py_ssize_t count = -1;
 
     if (!PyArg_ParseTuple(args,
-        "OO|n:replace",
+        "y*y*|n:replace",
         &old, &new, &count))
         goto exit;
-    return_value = bytes_replace_impl(self, old, new, count);
+    return_value = bytes_replace_impl(self, &old, &new, count);
 
 exit:
+    /* Cleanup for old */
+    if (old.obj)
+       PyBuffer_Release(&old);
+    /* Cleanup for new */
+    if (new.obj)
+       PyBuffer_Release(&new);
+
     return return_value;
 }
 
 static PyObject *
-bytes_replace_impl(PyBytesObject*self, PyObject *old, PyObject *new, Py_ssize_t count)
-/*[clinic end generated code: output=14ce72f4f9cb91cf input=d3ac254ea50f4ac1]*/
+bytes_replace_impl(PyBytesObject*self, Py_buffer *old, Py_buffer *new, Py_ssize_t count)
+/*[clinic end generated code: output=f07bd9ecf29ee8d8 input=b2fbbf0bf04de8e5]*/
 {
-    const char *old_s, *new_s;
-    Py_ssize_t old_len, new_len;
-
-    if (PyBytes_Check(old)) {
-        old_s = PyBytes_AS_STRING(old);
-        old_len = PyBytes_GET_SIZE(old);
-    }
-    else if (PyObject_AsCharBuffer(old, &old_s, &old_len))
-        return NULL;
-
-    if (PyBytes_Check(new)) {
-        new_s = PyBytes_AS_STRING(new);
-        new_len = PyBytes_GET_SIZE(new);
-    }
-    else if (PyObject_AsCharBuffer(new, &new_s, &new_len))
-        return NULL;
-
     return (PyObject *)replace((PyBytesObject *) self,
-                               old_s, old_len,
-                               new_s, new_len, count);
+                               (const char *)old->buf, old->len,
+                               (const char *)new->buf, new->len, count);
 }
 
 /** End DALKE **/
@@ -3181,6 +3198,7 @@ _bytes_tailmatch(PyBytesObject *self, PyObject *substr, Py_ssize_t start,
 {
     Py_ssize_t len = PyBytes_GET_SIZE(self);
     Py_ssize_t slen;
+    Py_buffer sub_view = {NULL, NULL};
     const char* sub;
     const char* str;
 
@@ -3188,8 +3206,12 @@ _bytes_tailmatch(PyBytesObject *self, PyObject *substr, Py_ssize_t start,
         sub = PyBytes_AS_STRING(substr);
         slen = PyBytes_GET_SIZE(substr);
     }
-    else if (PyObject_AsCharBuffer(substr, &sub, &slen))
-        return -1;
+    else {
+        if (PyObject_GetBuffer(substr, &sub_view, PyBUF_SIMPLE) != 0)
+            return -1;
+        sub = sub_view.buf;
+        slen = sub_view.len;
+    }
     str = PyBytes_AS_STRING(self);
 
     ADJUST_INDICES(start, end, len);
@@ -3197,17 +3219,25 @@ _bytes_tailmatch(PyBytesObject *self, PyObject *substr, Py_ssize_t start,
     if (direction < 0) {
         /* startswith */
         if (start+slen > len)
-            return 0;
+            goto notfound;
     } else {
         /* endswith */
         if (end-start < slen || start > len)
-            return 0;
+            goto notfound;
 
         if (end-slen > start)
             start = end - slen;
     }
-    if (end-start >= slen)
-        return ! memcmp(str+start, sub, slen);
+    if (end-start < slen)
+        goto notfound;
+    if (memcmp(str+start, sub, slen) != 0)
+        goto notfound;
+
+    PyBuffer_Release(&sub_view);
+    return 1;
+
+notfound:
+    PyBuffer_Release(&sub_view);
     return 0;
 }
 
@@ -3978,7 +4008,7 @@ PyBytes_Concat(PyObject **pv, PyObject *w)
         Py_buffer wb;
 
         wb.len = -1;
-        if (_getbuffer(w, &wb) < 0) {
+        if (PyObject_GetBuffer(w, &wb, PyBUF_SIMPLE) != 0) {
             PyErr_Format(PyExc_TypeError, "can't concat %.100s to %.100s",
                          Py_TYPE(w)->tp_name, Py_TYPE(*pv)->tp_name);
             Py_CLEAR(*pv);
diff --git a/Objects/complexobject.c b/Objects/complexobject.c
index 7e2e88a3ae..dc1212e4b7 100644
--- a/Objects/complexobject.c
+++ b/Objects/complexobject.c
@@ -767,6 +767,7 @@ complex_subtype_from_string(PyTypeObject *type, PyObject *v)
     int got_bracket=0;
     PyObject *s_buffer = NULL;
     Py_ssize_t len;
+    Py_buffer view = {NULL, NULL};
 
     if (PyUnicode_Check(v)) {
         s_buffer = _PyUnicode_TransformDecimalAndSpaceToASCII(v);
@@ -776,7 +777,11 @@ complex_subtype_from_string(PyTypeObject *type, PyObject *v)
         if (s == NULL)
             goto error;
     }
-    else if (PyObject_AsCharBuffer(v, &s, &len)) {
+    else if (PyObject_GetBuffer(v, &view, PyBUF_SIMPLE) == 0) {
+        s = (const char *)view.buf;
+        len = view.len;
+    }
+    else {
         PyErr_Format(PyExc_TypeError,
             "complex() argument must be a string or a number, not '%.200s'",
             Py_TYPE(v)->tp_name);
@@ -890,6 +895,7 @@ complex_subtype_from_string(PyTypeObject *type, PyObject *v)
     if (s-start != len)
         goto parse_error;
 
+    PyBuffer_Release(&view);
     Py_XDECREF(s_buffer);
     return complex_subtype_from_doubles(type, x, y);
 
@@ -897,6 +903,7 @@ complex_subtype_from_string(PyTypeObject *type, PyObject *v)
     PyErr_SetString(PyExc_ValueError,
                     "complex() arg is a malformed string");
   error:
+    PyBuffer_Release(&view);
     Py_XDECREF(s_buffer);
     return NULL;
 }
diff --git a/Objects/exceptions.c b/Objects/exceptions.c
index 5532821aa6..e09d384faa 100644
--- a/Objects/exceptions.c
+++ b/Objects/exceptions.c
@@ -1922,8 +1922,6 @@ static int
 UnicodeDecodeError_init(PyObject *self, PyObject *args, PyObject *kwds)
 {
     PyUnicodeErrorObject *ude;
-    const char *data;
-    Py_ssize_t size;
 
     if (BaseException_init((PyBaseExceptionObject *)self, args, kwds) == -1)
         return -1;
@@ -1944,21 +1942,27 @@ UnicodeDecodeError_init(PyObject *self, PyObject *args, PyObject *kwds)
              return -1;
     }
 
-    if (!PyBytes_Check(ude->object)) {
-        if (PyObject_AsReadBuffer(ude->object, (const void **)&data, &size)) {
-            ude->encoding = ude->object = ude->reason = NULL;
-            return -1;
-        }
-        ude->object = PyBytes_FromStringAndSize(data, size);
-    }
-    else {
-        Py_INCREF(ude->object);
-    }
-
     Py_INCREF(ude->encoding);
+    Py_INCREF(ude->object);
     Py_INCREF(ude->reason);
 
+    if (!PyBytes_Check(ude->object)) {
+        Py_buffer view;
+        if (PyObject_GetBuffer(ude->object, &view, PyBUF_SIMPLE) != 0)
+            goto error;
+        Py_CLEAR(ude->object);
+        ude->object = PyBytes_FromStringAndSize(view.buf, view.len);
+        PyBuffer_Release(&view);
+        if (!ude->object)
+            goto error;
+    }
     return 0;
+
+error:
+    Py_CLEAR(ude->encoding);
+    Py_CLEAR(ude->object);
+    Py_CLEAR(ude->reason);
+    return -1;
 }
 
 static PyObject *
diff --git a/Objects/floatobject.c b/Objects/floatobject.c
index dceb55ef29..8d85121910 100644
--- a/Objects/floatobject.c
+++ b/Objects/floatobject.c
@@ -131,6 +131,7 @@ PyFloat_FromString(PyObject *v)
     double x;
     PyObject *s_buffer = NULL;
     Py_ssize_t len;
+    Py_buffer view = {NULL, NULL};
     PyObject *result = NULL;
 
     if (PyUnicode_Check(v)) {
@@ -143,7 +144,11 @@ PyFloat_FromString(PyObject *v)
             return NULL;
         }
     }
-    else if (PyObject_AsCharBuffer(v, &s, &len)) {
+    else if (PyObject_GetBuffer(v, &view, PyBUF_SIMPLE) == 0) {
+        s = (const char *)view.buf;
+        len = view.len;
+    }
+    else {
         PyErr_Format(PyExc_TypeError,
             "float() argument must be a string or a number, not '%.200s'",
             Py_TYPE(v)->tp_name);
@@ -170,6 +175,7 @@ PyFloat_FromString(PyObject *v)
     else
         result = PyFloat_FromDouble(x);
 
+    PyBuffer_Release(&view);
     Py_XDECREF(s_buffer);
     return result;
 }
diff --git a/Objects/stringlib/join.h b/Objects/stringlib/join.h
index 35eb984352..cbf81be170 100644
--- a/Objects/stringlib/join.h
+++ b/Objects/stringlib/join.h
@@ -58,7 +58,14 @@ STRINGLIB(bytes_join)(PyObject *sep, PyObject *iterable)
     for (i = 0, nbufs = 0; i < seqlen; i++) {
         Py_ssize_t itemlen;
         item = PySequence_Fast_GET_ITEM(seq, i);
-        if (_getbuffer(item, &buffers[i]) < 0) {
+        if (PyBytes_CheckExact(item)) {
+            /* Fast path. */
+            Py_INCREF(item);
+            buffers[i].obj = item;
+            buffers[i].buf = PyBytes_AS_STRING(item);
+            buffers[i].len = PyBytes_GET_SIZE(item);
+        }
+        else if (PyObject_GetBuffer(item, &buffers[i], PyBUF_SIMPLE) != 0) {
             PyErr_Format(PyExc_TypeError,
                          "sequence item %zd: expected a bytes-like object, "
                          "%.80s found",
diff --git a/Python/bltinmodule.c b/Python/bltinmodule.c
index 068398fb9b..f9bb388b5a 100644
--- a/Python/bltinmodule.c
+++ b/Python/bltinmodule.c
@@ -723,10 +723,10 @@ builtin_chr_impl(PyModuleDef *module, int i)
 }
 
 
-static char *
-source_as_string(PyObject *cmd, char *funcname, char *what, PyCompilerFlags *cf)
+static const char *
+source_as_string(PyObject *cmd, const char *funcname, const char *what, PyCompilerFlags *cf, Py_buffer *view)
 {
-    char *str;
+    const char *str;
     Py_ssize_t size;
 
     if (PyUnicode_Check(cmd)) {
@@ -735,19 +735,21 @@ source_as_string(PyObject *cmd, char *funcname, char *what, PyCompilerFlags *cf)
         if (str == NULL)
             return NULL;
     }
-    else if (!PyObject_CheckReadBuffer(cmd)) {
+    else if (PyObject_GetBuffer(cmd, view, PyBUF_SIMPLE) == 0) {
+        str = (const char *)view->buf;
+        size = view->len;
+    }
+    else {
         PyErr_Format(PyExc_TypeError,
           "%s() arg 1 must be a %s object",
           funcname, what);
         return NULL;
     }
-    else if (PyObject_AsReadBuffer(cmd, (const void **)&str, &size) < 0) {
-        return NULL;
-    }
 
-    if (strlen(str) != (size_t)size)  {
+    if (strlen(str) != (size_t)size) {
         PyErr_SetString(PyExc_ValueError,
                         "source code string cannot contain null bytes");
+        PyBuffer_Release(view);
         return NULL;
     }
     return str;
@@ -827,7 +829,8 @@ static PyObject *
 builtin_compile_impl(PyModuleDef *module, PyObject *source, PyObject *filename, const char *mode, int flags, int dont_inherit, int optimize)
 /*[clinic end generated code: output=c72d197809d178fc input=c6212a9d21472f7e]*/
 {
-    char *str;
+    Py_buffer view = {NULL, NULL};
+    const char *str;
     int compile_mode = -1;
     int is_ast;
     PyCompilerFlags cf;
@@ -898,11 +901,12 @@ builtin_compile_impl(PyModuleDef *module, PyObject *source, PyObject *filename,
         goto finally;
     }
 
-    str = source_as_string(source, "compile", "string, bytes or AST", &cf);
+    str = source_as_string(source, "compile", "string, bytes or AST", &cf, &view);
     if (str == NULL)
         goto error;
 
     result = Py_CompileStringObject(str, filename, start[compile_mode], &cf, optimize);
+    PyBuffer_Release(&view);
     goto finally;
 
 error:
@@ -1042,7 +1046,8 @@ builtin_eval_impl(PyModuleDef *module, PyObject *source, PyObject *globals, PyOb
 /*[clinic end generated code: output=644fd59012538ce6 input=31e42c1d2125b50b]*/
 {
     PyObject *result, *tmp = NULL;
-    char *str;
+    Py_buffer view = {NULL, NULL};
+    const char *str;
     PyCompilerFlags cf;
 
     if (locals != Py_None && !PyMapping_Check(locals)) {
@@ -1089,7 +1094,7 @@ builtin_eval_impl(PyModuleDef *module, PyObject *source, PyObject *globals, PyOb
     }
 
     cf.cf_flags = PyCF_SOURCE_IS_UTF8;
-    str = source_as_string(source, "eval", "string, bytes or code", &cf);
+    str = source_as_string(source, "eval", "string, bytes or code", &cf, &view);
     if (str == NULL)
         return NULL;
 
@@ -1098,6 +1103,7 @@ builtin_eval_impl(PyModuleDef *module, PyObject *source, PyObject *globals, PyOb
 
     (void)PyEval_MergeCompilerFlags(&cf);
     result = PyRun_StringFlags(str, Py_eval_input, globals, locals, &cf);
+    PyBuffer_Release(&view);
     Py_XDECREF(tmp);
     return result;
 }
@@ -1204,11 +1210,12 @@ builtin_exec_impl(PyModuleDef *module, PyObject *source, PyObject *globals, PyOb
         v = PyEval_EvalCode(source, globals, locals);
     }
     else {
-        char *str;
+        Py_buffer view = {NULL, NULL};
+        const char *str;
         PyCompilerFlags cf;
         cf.cf_flags = PyCF_SOURCE_IS_UTF8;
         str = source_as_string(source, "exec",
-                                       "string, bytes or code", &cf);
+                                       "string, bytes or code", &cf, &view);
         if (str == NULL)
             return NULL;
         if (PyEval_MergeCompilerFlags(&cf))
@@ -1216,6 +1223,7 @@ builtin_exec_impl(PyModuleDef *module, PyObject *source, PyObject *globals, PyOb
                                   locals, &cf);
         else
             v = PyRun_String(str, Py_file_input, globals, locals);
+        PyBuffer_Release(&view);
     }
     if (v == NULL)
         return NULL;