* let me declare single limit
* use our new limit in process_frame_chain()
* add it in parse_async_frame_chain()
* parse_coro_chain()
* NEWS
* async in the message?
* test
* no race
* process_task_awaited_by
* process_task_awaited_by limit test
* NEWS
* MAX_TASK_WAITER_CHAIN_DEPTH
* TASK_WAITER_CHAIN_DEPTH in test
* TASK_WAITER_CHAIN_DEPTH 256
* prevent the drift with the comment
* better naming, better style
* MAX_TASK_WAITER_CHAIN_DEPTH comment
* task-waiter iterative bfs walk
* iterative coro-walk
* nicer news
* 1 << 14
* comment
* unused read_Py_ssize_t
* fix tombstones
* simplify
* correct msg
* better test
* news for tombstones
* left-over from when testing buggy version
* redundant new line
Treat the debug offset tables read from a target process as untrusted input
and validate them before the unwinder uses any reported sizes or offsets.
Add a shared validator in debug_offsets_validation.h and run it once when
_Py_DebugOffsets is loaded and once when AsyncioDebug is loaded. The checks
cover section sizes used for fixed local buffers and every offset that is
later dereferenced against a local buffer or local object view. This keeps
the bounds checks out of the sampling hot path while rejecting malformed
tables up front.
When _ctypes is imported, it may call dlopen on the libpython shared
library, causing the dynamic linker to load a second mapping of the
library into the process address space. The remote debugging code
iterates memory regions from low addresses upward and returns the first
mapping whose filename matches libpython. After _ctypes is imported, it
finds the dlopen'd copy first, but that copy's PyRuntime section was
never initialized, so reading debug offsets from it fails.
Fix this by validating each candidate PyRuntime address before accepting
it. The validation reads the first 8 bytes and checks for the "xdebugpy"
cookie that is only present in an initialized PyRuntime. Uninitialized
duplicate mappings will fail this check and be skipped, allowing the
search to continue to the real, initialized PyRuntime.
Kumar Aditya