* bpo-9263: _PyObject_Dump() detects freed memory (GH-10061)
_PyObject_Dump() now uses an heuristic to check if the object memory
has been freed: log "<freed object>" in that case.
The heuristic rely on the debug hooks on Python memory allocators
which fills the memory with DEADBYTE (0xDB) when memory is
deallocated. Use PYTHONMALLOC=debug to always enable these debug
hooks.
(cherry picked from commit 82af0b63b0)
* bpo-9263: Fix _PyObject_Dump() for freed object (#10661)
If _PyObject_Dump() detects that the object is freed, don't try to
dump it (exit immediately).
Enhance also _PyObject_IsFreed(): it now detects if the pointer
itself looks like freed memory.
(cherry picked from commit 2cf5d32fd9)
This function may access memory which is mapped but is considered
free by libc allocator. It behaves so by design, therefore we
need to suppress sanitizer reports.
GCC doesn't support MSan, so disable only TSan for it.
(cherry picked from commit fd3a91cbf9)
Co-authored-by: Alexey Izbyshev <izbyshev@ispras.ru>
Fix typos found by codespell in docs, docstrings, and comments.
(cherry picked from commit c3d9508ff2)
Co-authored-by: Leo Arias <leo.arias@canonical.com>
* Py_Main() now starts by reading Py_xxx configuration variables to
only work on its own private structure, and then later writes back
the configuration into these variables.
* Replace Py_GETENV() with pymain_get_env_var() which ignores empty
variables.
* Add _PyCoreConfig.dump_refs
* Add _PyCoreConfig.malloc_stats
* _PyObject_DebugMallocStats() is now responsible to check if debug
hooks are installed. The function returns 1 if stats were written,
or 0 if the hooks are disabled. Mark _PyMem_PymallocEnabled() as
static.
* Rename PyPathConfig structure to _PyPathConfig and move it to
Include/internal/pystate.h
* Rename path_config to _Py_path_config
* _PyPathConfig: Rename program_name field to program_full_path
* Add assert(str != NULL); to _PyMem_RawWcsdup(), _PyMem_RawStrdup()
and _PyMem_Strdup().
* Rename calculate_path() to pathconfig_global_init(). The function
now does nothing if it's already initiallized.
* Fix _PyMem_SetupAllocators("debug"): always restore allocators to
the defaults, rather than only caling _PyMem_SetupDebugHooks().
* Add _PyMem_SetDefaultAllocator() helper to set the "default"
allocator.
* Add _PyMem_GetAllocatorsName(): get the name of the allocators
* main() now uses debug hooks on memory allocators if Py_DEBUG is
defined, rather than calling directly malloc()
* Document default memory allocators in C API documentation
* _Py_InitializeCore() now fails with a fatal user error if
PYTHONMALLOC value is an unknown memory allocator, instead of
failing with a fatal internal error.
* Add new tests on the PYTHONMALLOC environment variable
* Add support.with_pymalloc()
* Add the _testcapi.WITH_PYMALLOC constant and expose it as
support.with_pymalloc().
* sysconfig.get_config_var('WITH_PYMALLOC') doesn't work on Windows, so
replace it with support.with_pymalloc().
* pythoninfo: add _testcapi collector for pymem
Py_GetPath() and Py_Main() now call
_PyMainInterpreterConfig_ReadEnv() to share the same code to get
environment variables.
Changes:
* Add _PyMainInterpreterConfig_ReadEnv()
* Add _PyMainInterpreterConfig_Clear()
* Add _PyMem_RawWcsdup()
* _PyMainInterpreterConfig: rename pythonhome to home
* Rename _Py_ReadMainInterpreterConfig() to
_PyMainInterpreterConfig_Read()
* Use _Py_INIT_USER_ERR(), instead of _Py_INIT_ERR(), for decoding
errors: the user is able to fix the issue, it's not a bug in
Python. Same change was made in _Py_INIT_NO_MEMORY().
* Remove _Py_GetPythonHomeWithConfig()
bpo-32096, bpo-30860: Partially revert the commit
2ebc5ce42a:
* Move structures back from Include/internal/mem.h to
Objects/obmalloc.c
* Remove _PyObject_Initialize() and _PyMem_Initialize()
* Remove Include/internal/pymalloc.h
* Add test_capi.test_pre_initialization_api():
Make sure that it's possible to call Py_DecodeLocale(), and then call
Py_SetProgramName() with the decoded string, before Py_Initialize().
PyMem_RawMalloc() and Py_DecodeLocale() can be called again before
_PyRuntimeState_Init().
Co-Authored-By: Eric Snow <ericsnowcurrently@gmail.com>
Add a new "developer mode": new "-X dev" command line option to
enable debug checks at runtime.
Changes:
* Add unit tests for -X dev
* test_cmd_line: replace test.support with support.
* Fix _PyRuntimeState_Fini(): Use the same memory allocator
than _PyRuntimeState_Init().
* Fix _PyMem_GetDefaultRawAllocator()
* Don't use "Python runtime" anymore to parse command line options or
to get environment variables: pymain_init() is now a strict
separation.
* Use an error message rather than "crashing" directly with
Py_FatalError(). Limit the number of calls to Py_FatalError(). It
prepares the code to handle errors more nicely later.
* Warnings options (-W, PYTHONWARNINGS) and "XOptions" (-X) are now
only added to the sys module once Python core is properly
initialized.
* _PyMain is now the well identified owner of some important strings
like: warnings options, XOptions, and the "program name". The
program name string is now properly freed at exit.
pymain_free() is now responsible to free the "command" string.
* Rename most methods in Modules/main.c to use a "pymain_" prefix to
avoid conflits and ease debug.
* Replace _Py_CommandLineDetails_INIT with memset(0)
* Reorder a lot of code to fix the initialization ordering. For
example, initializing standard streams now comes before parsing
PYTHONWARNINGS.
* Py_Main() now handles errors when adding warnings options and
XOptions.
* Add _PyMem_GetDefaultRawAllocator() private function.
* Cleanup _PyMem_Initialize(): remove useless global constants: move
them into _PyMem_Initialize().
* Call _PyRuntime_Initialize() as soon as possible:
_PyRuntime_Initialize() now returns an error message on failure.
* Add _PyInitError structure and following macros:
* _Py_INIT_OK()
* _Py_INIT_ERR(msg)
* _Py_INIT_USER_ERR(msg): "user" error, don't abort() in that case
* _Py_INIT_FAILED(err)
Few bytes at the begin and at the end of the reallocated blocks, as well
as the header and the trailer, now are erased before calling realloc()
in debug build. This will help to detect using or double freeing the
reallocated block.
Cleanup pymalloc:
* Rename _PyObject_Alloc() to pymalloc_alloc()
* Rename _PyObject_FreeImpl() to pymalloc_free()
* Rename _PyObject_Realloc() to pymalloc_realloc()
* pymalloc_alloc() and pymalloc_realloc() don't fallback on the raw
allocator anymore, it now must be done by the caller
* Add "success" and "failed" labels to pymalloc_alloc() and
pymalloc_free()
* pymalloc_alloc() and pymalloc_free() don't update
num_allocated_blocks anymore: it should be done in the caller
* _PyObject_Calloc() is now responsible to fill the memory block
allocated by pymalloc with zeros
* Simplify pymalloc_alloc() prototype
* _PyObject_Realloc() now calls _PyObject_Malloc() rather than
calling directly pymalloc_alloc()
_PyMem_DebugRawAlloc() and _PyMem_DebugRawRealloc():
* document the layout of a memory block
* don't increase the serial number if the allocation failed
* check for integer overflow before computing the total size
* add a 'data' variable to make the code easiler to follow
test_setallocators() of _testcapimodule.c now test also the context.
* group the (stateful) runtime globals into various topical structs
* consolidate the topical structs under a single top-level _PyRuntimeState struct
* add a check-c-globals.py script that helps identify runtime globals
Other globals are excluded (see globals.txt and check-c-globals.py).
* group the (stateful) runtime globals into various topical structs
* consolidate the topical structs under a single top-level _PyRuntimeState struct
* add a check-c-globals.py script that helps identify runtime globals
Other globals are excluded (see globals.txt and check-c-globals.py).
Fix MemoryError caused by moving around code in PR #886; nbytes was sometimes used unitinitalized (in non-debug builds, when use_calloc was false and elsize was 0).
Make a non-Py_DEBUG, asserts-enabled build of CPython possible. This means
making sure helper functions are defined when NDEBUG is not defined, not
just when Py_DEBUG is defined.
Also fix a division-by-zero in obmalloc.c that went unnoticed because in Py_DEBUG mode, elsize is never zero.
- Rename Py_ADDRESS_IN_RANGE to address_in_range and make it a static
function instead of macro. Any compiler worth its salt will inline this
function.
- Remove the duplicated function version of Py_ADDRESS_IN_RANGE used when memory
analysis was active. Instead, we can simply mark address_in_range as allergic
to dynamic memory checking. We can now remove the
__attribute__((no_address_safety_analysis)) from _PyObject_Free and
_PyObject_Realloc. All the badness is contained in address_in_range now.
- Fix the code that tried to only read pool->arenaindex once. Putting something
in a variable is no guarantee that it won't be read multiple times. We must
use volatile for that.
