Treat them as read-only, and make a copy as appropriately. This was
first reported by Bill Janssend and later by Craig Rowland and Ron
Sedlmeyer. This fix is mine.
"""
It fixes a memory corruption error resulting from BadPickleGet
exceptions in load_get, load_binget and load_long_binget. This was
initially reported on c.l.py as a problem with Cookie.py; see the thread
titled "python core dump (SIGBUS) on Solaris" for more details.
If PyDict_GetItem(self->memo, py_key) call failed, then py_key was being
Py_DECREF'd out of existence before call was made to
PyErr_SetObject(BadPickleGet, py_key).
The bug can be duplicated as follows:
import cPickle
cPickle.loads('garyp')
This raises a BadPickleGet exception whose value is a freed object. A
core dump will soon follow.
"""
Jim Fulton approves of the patch.
different values in the environ dict with the same key (although he
couldn't explain exactly how this came to be). Since getenv() uses
the first one, Python should do too. (Some doubts about case
sensitivity, but for now this at least seems the right thing to do
regardless of platform.)
- Don't call Py_FatalError() when initialization fails.
- Fix bogus use of return value from PyRun_String().
- Fix misc. compiler errors on some platforms.
I've updated cPickle.c to use class exceptions:
Changed pickle error types to classes:
PickleError
PicklingError
UnpickleableError
UnpicklingError
And change the handling of unpickleable objects so that an UnpickleableError
is raised with the unpickleable object as the argument. UnpickleableError
has a reasonable string representation and provides access to the problem
object, which is useful during debugging.
[I'm still waiting for patches to do the same to pickle.py.]
The test really wanted to distinguish between the two. So now we test
for __GLIBC__ instead. I have confirmed that this works for glibc and
I have an email from Christian Tanzer confirming that it works for
libc5, so it should be fine.
I have attached a new cPickle that adds a new control attribute
to unpicklers:
Added new Unpickler attribute, find_global. If set to None, then
global and instance pickles are disabled. Otherwise, it should be set to
a callable object that takes two arguments, a module name and an
object name, and returns an object. If the attribute is unset, then
the default mechanism is used.
This feature provides an additional mechanism for controlling which
classes can be used for unpickling.
Without this, if inflate() returned Z_BUF_ERROR asking for more output
space, we would report the error; now, we increase the buffer size and
try again, just as for Z_OK.
"""
The GNU folks, in their infinite wisdom, have decided not to implement
altzone in libc6; this would not be horrible, except that timezone
(which is implemented) includes the current DST setting (i.e. timezone
for Central is 18000 in summer and 21600 in winter). So Python's
timezone and altzone variables aren't set correctly during DST.
Here's a patch relative to 1.5.2b2 that (a) makes timezone and altzone
show the "right" thing on Linux (by using the tm_gmtoff stuff
available in BSD, which is how the GLIBC manual claims things should
be done) and (b) should cope with the southern hemisphere. In pursuit
of (b), I also took the liberty of renaming the "summer" and "winter"
variables to "july" and "jan". This patch should also make certain
time calculations on Linux actually work right (like the tz-aware
functions in the rfc822 module).
(It's hard to find DST that's currently being used in the southern
hemisphere; I tested using Africa/Windhoek.)
"""
is not an empty string, this means that you have arrived at the
end of the stream of compressed data, and the contents of .unused_data are
whatever follows the compressed stream.
data struct before calling gethostby{name,addr}_r(); (2) ignore the
3/5/6 args determinations made by the configure script and switch on
platform identifiers instead:
AIX, OSF have 3 args
Sun, SGI have 5 args
Linux has 6 args
On all other platforms, undef HAVE_GETHOSTBYNAME_R altogether.
- Use HAVE_GETHOSTBYNAME_R_6_ARG instead of testing for Linux and
glibc2.
- If gethostbyname takes 3 args, undefine HAVE_GETHOSTBYNAME_R --
don't know what code should be used.
- New symbol USE_GETHOSTBYNAME_LOCK defined iff the lock should be used.
- Modify the gethostbyaddr() code to also hold on to the lock until
after it is safe to release, overlapping with the Python lock.
(Note: I think that it could in theory be possible that Python code
executed while gethostbyname_lock is held could attempt to reacquire
the lock -- e.g. in a signal handler or destructor. I will simply say
"don't do that then.")
Here's a patch to fix the race condition, which wasn't fixed by Rob's
patch. It holds the gethostbyname lock until the results are copied out,
which means that this lock and the Python global lock are held at the same
time. This shouldn't be a problem as long as the gethostbyname lock is
always acquired when the global lock is not held.
He writes:
I had an off-by-1000 error in floatsleep(),
and the problem with time.clock() is that it's not implemented properly
on QNX... ANSI says it's supposed to return _CPU_ time used by the
process, but on QNX it returns the amount of real time used... so I was
confused.
guessing what happened when strftime() returns 0. Is it buffer
overflow or was the result simply 0 bytes long? (This happens for an
empty format string, or when the format string is a single %Z and the
timezone is unknown.) if the buffer is at least 256 times as long as
the format, assume the latter.
converted was a "digit" -- use isalnum(). This test is there only to
guard against "+" or "-" being interpreted as a valid int literal.
Reported by Takahiro Nakayama.
up the _tkinter main loop. Not clear why; the _kbhit() call _tkinter
makes probably confuses the stdio library when buffering isn't set to
whatever it is by default.
f_fsid field, since it's not a scalar on all systems supporting this
call (in particular, it's a tuple of two longs on AIX). Since it's
not particularly useful, just nuke it. Adapted the doc strings too.
was appended to a list. Lists are reference count neutral, so the
string must be DECREF'd. Also added some checks for the return value
of PyList_Append().
Note: there are still some memory problems reported by Purify (I get
two Array Bounds Reads still and an Unitialized Memory Read). Also,
in scanning the code, there appears to be some potential problems
where return values aren't checked. To much to attack now though.
Purify) being caused by a bug in the readline library. Nothing we can
do about it.
Cause: readline_initialize_everything() throws away the return value
from rl_read_init_file(), but that happens to be the last reference to
a dynamically allocated char*.
decompressor object. This required adding a flag to the struct which is
true if initialisation was completed; on object destruction, deflateEnd()
is only called if the flag is true.
NOTE: There is still a bug of some sort in the behavior of zlib. In
at least one case, inflate returns Z_OK (which is typically
interpreted to mean that more output space is needed) when it has
finished inflating a buffer. This has been reported as a bug to the
zlib maintainers; we may need to change the Python interface.
Fred Drake
Guido van Rossum
Barry Warsaw
Andrew M. Kuchling
Jeremy Hylton