This reverts one part of commit 85235aec83 related to reference
counts. Py_BuildValue always increments the reference count (when it
succeeds) and I could not reproduce the Python 3 problem that was
described there.
Reviewed-by: Laszlo Ersek <lersek@redhat.com>
The event callback gets a buffer parameter which is usually something
like a log message. However as it comes from C it is not necessarily
well-formed (eg) UTF-8 but could contain any old sequence of bytes.
In the test case provided by the reporter, we failed to encode the
buffer as 'str' with this error:
UnicodeDecodeError: 'utf-8' codec can't decode byte 0xc3 in position 137: unexpected end of data
Use 'bytes' instead. Strictly speaking this changes the type
signature of the callbacks, but our existing Python tests which just
print the buffer using '%s' don't fail and in any case we don't
guarantee the stability of non-C APIs.
Reported-by: Yonatan Shtarkman
See: https://listman.redhat.com/archives/libguestfs/2023-February/030653.html
In the case that building the parameters to the Python event callback
fails, args was returned as NULL. We immediately tried to call
Py_INCREF on this which crashed. Returning NULL means the Python
function threw an exception, so print the exception and return (there
is no way to return an error here - the event is lost).
Reported-by: Yonatan Shtarkman
See: https://listman.redhat.com/archives/libguestfs/2023-February/030653.html
Run this command across the source:
perl -pi.bak -e 's/(20[012][0-9])-20[12][012]/$1-2023/g' `git ls-files`
and remove changes to po{,-docs}/*.po{,t} (these will be regenerated
later when we run 'make dist').
Python 2 reached end of life on 2020-01-01:
https://python3statement.org/https://pythonclock.org/
The minimum version required is now Python 3.4 (since that is the
version in Debian oldoldstable), but 3.6 is the minimum version that
I actually test.
This symbol is not present in Python 2.7 or 3.6. It's not really
necessary to call this, it just avoids a crash in certain corner cases
when the interpreter is shutting down. So make the call conditional
on the function existing.
Fixes commit e6f9e0b0f6.
The PyString API is specific to Python < 3, replaced by PyBytes and
PyUnicode in Python 3+; hence, drop the compile time check, and use the
right API depending on the Python version.
If you've registered a callback in Python and the handle is implicitly
closed when the Python interpreter exits, then it can be that the
following happens:
- Python interpreter is finalized.
- guestfs_close is called
- callback is invoked (eg. close event or to display a debug message)
- Python code runs from the callback wrapper
This cause a segfault on shutdown. Catch this case and stop the
callback from running (we lose the event but given the above sequence
of events there's not much we can do about it).
See:
https://bugzilla.redhat.com/show_bug.cgi?id=1773520#c7
All Py_* functions should be protected by the GIL.
Otherwise internal python data structures can get corrupted.
Move PyGILState_Ensure to the beginning of the block and
PyGILState_Release to the bottom.
Signed-off-by: Sam Eiderman <sameid@google.com>
Previously to work around some problems in Python 2 header files we
had to include <Python.h> before any other config file.
For Python 3 which is all we really care about now this is no longer
needed. We can move the include from three files into the local
"actions.h" file, bringing all the Python definitions and workarounds
into a single place.
Make sure to reference the arguments, to make sure they are kept alive
during the function call; this is visible when setting an event handler
for the CLOSE event, and testing it with Python 3.
This does not seem to create a memory leak e.g. with Python 2.
Also, switch away from the quasi-internal PyEval_CallObject to the
public PyObject_CallObject, which takes care of doing safety checks.
Verify the returned values of Python Object constructor functions
are not NULL before adding them to a collection.
This is particularly relevant when constructing Unicode strings in
Python 3 as they will return NULL if non UTF-8 characters are present.
Signed-off-by: Matteo Cafasso <noxdafox@gmail.com>
Make use of functions and types that fit more, and that do the same job:
- use PyErr_NoMemory() on malloc failure
- use PyErr_SetFromErrno when setting an exception from an errno
- throw TypeError if not getting a list when required
The current need for #ifdef's based on the presence of
PyString_FromString makes both the OCaml code of the generator, and the
generated C code a mess to read.
Hence, add three simple wrappers to make both the OCaml, and C code more
readable, and easier to tweak in the future.
This should be just refactoring, with no actual behaviour changes.
Thanks to: Matteo Cafasso
In case there are no event handlers registered with the handle,
get_all_event_callbacks will count 0 elements, trying to malloc a buffer
of that size. POSIX says that this can result in either a null pointer,
or an unusable pointer.
Short-circuit get_all_event_callbacks to allocate nothing when there are
no events, making sure to use its results only when there were events.
Run the following command over the source:
perl -pi.bak -e 's/(20[01][0-9])-2016/$1-2017/g' `git ls-files`
(Thanks Rich for the perl snippet, as used in past years.)
