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Simon Marchi 6f8b04077b Fix python-interactive with Python 3.6
New in v2:

 - Define PyMem_RawMalloc as PyMem_Malloc for Python < 3.4 and use
   PyMem_RawMalloc in the code.

Since Python 3.4, the callback installed in PyOS_ReadlineFunctionPointer
should return a value allocated with PyMem_RawMalloc instead of
PyMem_Malloc.  The reason is that PyMem_Malloc must be called with the
Python Global Interpreter Lock (GIL) held, which is not the case in the
context where this function is called.  PyMem_RawMalloc was introduced
for cases like this.

In Python 3.6, it looks like they added an assert to verify that
PyMem_Malloc was not called without the GIL.  The consequence is that
typing anything in the python-interactive mode of gdb crashes the
process.  The same behavior was observed with the official package on
Arch Linux as well as with a manual Python build on Ubuntu 14.04.

This is what is shown with a debug build of Python 3.6 (the error with a
non-debug build is far less clear):

  (gdb) pi
  >>> print(1)
  Fatal Python error: Python memory allocator called without holding the GIL

  Current thread 0x00007f1459af8780 (most recent call first):
  [1]    21326 abort      ./gdb

and the backtrace:

  #0  0x00007ffff618bc37 in raise () from /lib/x86_64-linux-gnu/libc.so.6
  #1  0x00007ffff618f028 in abort () from /lib/x86_64-linux-gnu/libc.so.6
  #2  0x00007ffff6b104d6 in Py_FatalError (msg=msg@entry=0x7ffff6ba15b8 "Python memory allocator called without holding the GIL") at Python/pylifecycle.c:1457
  #3  0x00007ffff6a37a68 in _PyMem_DebugCheckGIL () at Objects/obmalloc.c:1972
  #4  0x00007ffff6a3804e in _PyMem_DebugFree (ctx=0x7ffff6e65290 <_PyMem_Debug+48>, ptr=0x24f8830) at Objects/obmalloc.c:1994
  #5  0x00007ffff6a38e1d in PyMem_Free (ptr=<optimized out>) at Objects/obmalloc.c:442
  #6  0x00007ffff6b866c6 in _PyFaulthandler_Fini () at ./Modules/faulthandler.c:1369
  #7  0x00007ffff6b104bd in Py_FatalError (msg=msg@entry=0x7ffff6ba15b8 "Python memory allocator called without holding the GIL") at Python/pylifecycle.c:1431
  #8  0x00007ffff6a37a68 in _PyMem_DebugCheckGIL () at Objects/obmalloc.c:1972
  #9  0x00007ffff6a37aa3 in _PyMem_DebugMalloc (ctx=0x7ffff6e65290 <_PyMem_Debug+48>, nbytes=5) at Objects/obmalloc.c:1980
  #10 0x00007ffff6a38d91 in PyMem_Malloc (size=<optimized out>) at Objects/obmalloc.c:418
  #11 0x000000000064dbe2 in gdbpy_readline_wrapper (sys_stdin=0x7ffff6514640 <_IO_2_1_stdin_>, sys_stdout=0x7ffff6514400 <_IO_2_1_stdout_>, prompt=0x7ffff4d4f7d0 ">>> ")
    at /home/emaisin/src/binutils-gdb/gdb/python/py-gdb-readline.c:75

The documentation is very clear about it [1] and it was also mentioned
in the "What's New In Python 3.4" page [2].

[1] https://docs.python.org/3/c-api/veryhigh.html#c.PyOS_ReadlineFunctionPointer
[2] https://docs.python.org/3/whatsnew/3.4.html#changes-in-the-c-api

gdb/ChangeLog:

	* python/python-internal.h (PyMem_RawMalloc): Define for
	Python < 3.4.
	* python/py-gdb-readline.c (gdbpy_readline_wrapper): Use
	PyMem_RawMalloc instead of PyMem_Malloc.
2017-01-20 20:39:08 -05:00
bfd Automatic date update in version.in 2017-01-21 00:00:21 +00:00
binutils objdump: Better objdump section headers in wide mode 2017-01-20 09:05:41 +00:00
config picflag.m4 high bit set in comment 2017-01-05 00:02:57 +10:30
cpu Add fall through comment to source in cpu/ 2016-10-06 22:48:37 +10:30
elfcpp Update year range in copyright notice of all files. 2017-01-02 14:08:56 +10:30
etc update-copyright.py for binutils 2017-01-05 00:03:07 +10:30
gas Fix potential array overrun in x86 assembler. 2017-01-20 10:32:25 +00:00
gdb Fix python-interactive with Python 3.6 2017-01-20 20:39:08 -05:00
gold Fix problem in aarch64 gold sources uncovered by Coverty - using sizeof on a pointer instead of an array. 2017-01-20 10:21:17 +00:00
gprof Update year range in copyright notice of all files. 2017-01-02 14:08:56 +10:30
include [DWARF] Sync GCC dwarf.def change on AArch64 2017-01-04 14:27:52 +00:00
intl
ld [AArch64] Optimize .gnu.hash table size for executable 2017-01-20 13:30:32 +00:00
libdecnumber
libiberty Sync libiberty from gcc 2017-01-05 00:03:07 +10:30
opcodes Updated Irish translation for the opcodes library. 2017-01-20 12:25:07 +00:00
readline Improve MinGW support in Readline 2016-09-17 11:50:37 +03:00
sim Fixes for addv and xtn2 instructions. 2017-01-17 16:11:09 -08:00
texinfo
zlib Sync zlib sources with GCC, upgrading to 1.2.10. 2017-01-20 10:17:42 +00:00
.cvsignore
.gitattributes
.gitignore Add archives and make stamps to the .gitignore file. 2016-09-27 15:10:42 +01:00
ChangeLog Import config.sub 2016-12-31 11:47:16 +10:30
compile
config-ml.in
config.guess Sync config.sub,config.guess with upstream. 2016-11-07 13:08:55 -08:00
config.rpath
config.sub Import config.sub 2016-12-31 11:47:16 +10:30
configure sync binutils config/ with gcc 2016-12-08 21:35:11 +10:30
configure.ac Add support for Fushia OS. 2016-12-02 10:44:29 +00:00
COPYING
COPYING3
COPYING3.LIB
COPYING.LIB
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COPYING.NEWLIB
depcomp
djunpack.bat
install-sh
libtool.m4 Sync top-level btool.m4 with GCC 2016-01-12 08:44:52 -08:00
lt~obsolete.m4
ltgcc.m4
ltmain.sh
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Makefile.in Add dependencies to configure rule 2016-05-28 22:36:04 +09:30
Makefile.tpl Add dependencies to configure rule 2016-05-28 22:36:04 +09:30
makefile.vms
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README
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setup.com
src-release.sh fix gdb version parsing in src-release.sh 2016-01-17 10:01:55 +04:00
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		   README for GNU development tools

This directory contains various GNU compilers, assemblers, linkers, 
debuggers, etc., plus their support routines, definitions, and documentation.

If you are receiving this as part of a GDB release, see the file gdb/README.
If with a binutils release, see binutils/README;  if with a libg++ release,
see libg++/README, etc.  That'll give you info about this
package -- supported targets, how to use it, how to report bugs, etc.

It is now possible to automatically configure and build a variety of
tools with one command.  To build all of the tools contained herein,
run the ``configure'' script here, e.g.:

	./configure 
	make

To install them (by default in /usr/local/bin, /usr/local/lib, etc),
then do:
	make install

(If the configure script can't determine your type of computer, give it
the name as an argument, for instance ``./configure sun4''.  You can
use the script ``config.sub'' to test whether a name is recognized; if
it is, config.sub translates it to a triplet specifying CPU, vendor,
and OS.)

If you have more than one compiler on your system, it is often best to
explicitly set CC in the environment before running configure, and to
also set CC when running make.  For example (assuming sh/bash/ksh):

	CC=gcc ./configure
	make

A similar example using csh:

	setenv CC gcc
	./configure
	make

Much of the code and documentation enclosed is copyright by
the Free Software Foundation, Inc.  See the file COPYING or
COPYING.LIB in the various directories, for a description of the
GNU General Public License terms under which you can copy the files.

REPORTING BUGS: Again, see gdb/README, binutils/README, etc., for info
on where and how to report problems.