binutils-gdb modified for the FreeChainXenon project
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Lancelot SIX 72994b6028 gdb/tui: install SIGWINCH only when connected to a TTY
PR26056 reports that when GDB is connected to non-TTY stdin/stdout, it
crashes when it receives a SIGWINCH signal.

This can be reproduced as follows:

    $ gdb/gdb -nx -batch -ex 'run' --args sleep 60 </dev/null 2>&1 | cat

    # from another terminal:
    $ kill -WINCH %(pidof gdb)

When doing so, the process crashes in a call to rl_resize_terminal:

    void
    rl_resize_terminal (void)
    {
      _rl_get_screen_size (fileno (rl_instream), 1);
      ...
    }

The problem is that at this point rl_instream has the value NULL.

The rl_instream variable is supposed to be initialized during a call to
readline_initialize_everything, which in a normal startup sequence is
called under this call chain:

    tui_interp::init
      tui_ensure_readline_initialized
        rl_initialize
          readline_initialize_everything

In tui_interp::init, we have the following sequence:

    tui_initialize_io ();
    tui_initialize_win ();                // <- Installs SIGWINCH
    if (gdb_stdout->isatty ())
      tui_ensure_readline_initialized (); // <- Initializes rl_instream

This function unconditionally installs the SIGWINCH signal handler (this
is done by tui_initialize_win), and then if gdb_stdout is a TTY it
initializes readline.  Therefore, if stdout is not a TTY, SIGWINCH is
installed but readline is not initialized.  In such situation
rl_instream stays NULL, and when GDB receives a SIGWINCH it calls its
handler and in fine tries to access rl_instream leading to the crash.

This patch proposes to fix this issue by installing the SIGWINCH signal
handler only if GDB is connected to a TTY.  Given that this
initialization it the only task of tui_initialize_win, this patch moves
tui_initialize_win just after the call to
tui_ensure_readline_initialized.

Tested on x86_64-linux.

Co-authored-by: Pedro Alves <pedro@palves.net>
Bug: https://sourceware.org/bugzilla/show_bug.cgi?id=26056
Change-Id: I6458acef7b0d9beda2a10715d0345f02361076d9
2021-12-17 03:56:25 -05:00
bfd asan: NULL dereference in bfd_elf_set_group_contents 2021-12-17 16:54:56 +10:30
binutils try_build_id_prefix gcc-10 -Wformat-security errors 2021-12-17 11:42:18 +10:30
config Deprecate a.out support for NetBSD targets. 2021-08-11 13:17:54 +01:00
contrib Import mklog.py from gcc repo 2020-09-25 10:24:44 -04:00
cpu Re: opcodes: constify & local meps macros 2021-07-05 21:40:49 +09:30
elfcpp [GOLD] PowerPC64 @notoc in non-power10 code 2021-12-11 14:52:36 +10:30
etc etc: switch to automake 2021-09-09 23:30:12 -04:00
gas Fix AVR assembler so that it creates relocs that will work with linker relaxation. 2021-12-16 16:40:57 +00:00
gdb gdb/tui: install SIGWINCH only when connected to a TTY 2021-12-17 03:56:25 -05:00
gdbserver New --enable-threading configure option to control use of threads in GDB/GDBserver 2021-12-15 17:00:00 -03:00
gdbsupport New --enable-threading configure option to control use of threads in GDB/GDBserver 2021-12-15 17:00:00 -03:00
gnulib gnulib: import various network functions 2021-09-08 17:48:09 -04:00
gold [GOLD] PowerPC64 @notoc in non-power10 code 2021-12-11 14:52:36 +10:30
gprof gprof: enable silent build rules 2021-11-29 20:28:29 -05:00
include arm: Add support for Armv9.1-A to Armv9.3-A 2021-12-16 09:32:00 +00:00
intl Regenerate a couple of files 2021-11-15 12:20:12 +10:30
ld Fix AVR assembler so that it creates relocs that will work with linker relaxation. 2021-12-16 16:40:57 +00:00
libbacktrace sync libbacktrace from gcc 2021-11-14 18:07:50 +10:30
libctf libctf: workaround automake bug with conditional info pages 2021-12-02 23:26:18 -05:00
libdecnumber Run autoreconf -vf throughout 2020-07-29 16:03:55 -04:00
libiberty Deprecate a.out support for NetBSD targets. 2021-08-11 13:17:54 +01:00
opcodes RISC-V: Support svinval extension with frozen version 1.0. 2021-12-16 16:04:53 +08:00
readline Update config.sub and config.guess for MIPS R3 and R5 ISA support 2021-05-24 18:11:49 +02:00
sim sim: mips/or1k: drop redundant arg to bitsize macro 2021-12-16 02:36:10 -05:00
texinfo
zlib zlib: enable silent build rules 2021-11-29 20:28:29 -05:00
.cvsignore
.gitattributes
.gitignore Add gnu global outputs to .gitignore 2020-12-02 10:00:27 -05:00
ar-lib
ChangeLog Document "memory-tag-violations". 2021-10-29 13:31:37 +03:00
compile
config-ml.in
config.guess Update config.sub and config.guess for MIPS R3 and R5 ISA support 2021-05-24 18:11:49 +02:00
config.rpath
config.sub Update config.sub and config.guess for MIPS R3 and R5 ISA support 2021-05-24 18:11:49 +02:00
configure top-level configure: setup target_configdirs based on repository 2021-09-28 12:21:21 +01:00
configure.ac top-level configure: setup target_configdirs based on repository 2021-09-28 12:21:21 +01:00
COPYING
COPYING.LIB
COPYING.LIBGLOSS
COPYING.NEWLIB
COPYING3
COPYING3.LIB
depcomp
djunpack.bat
install-sh
libtool.m4 libtool.m4: fix nm BSD flag detection 2021-09-27 20:31:23 +01:00
ltgcc.m4
ltmain.sh
ltoptions.m4
ltsugar.m4
ltversion.m4
lt~obsolete.m4
MAINTAINERS MAINTAINERS: Update path to readline config.{sub,guess} files 2021-05-24 18:11:49 +02:00
Makefile.def Import Makefile.def from gcc 2021-11-12 19:02:12 +10:30
Makefile.in Sync Makefile.tpl with GCC 2021-11-13 09:04:03 -08:00
Makefile.tpl Sync Makefile.tpl with GCC 2021-11-13 09:04:03 -08:00
makefile.vms
missing
mkdep
mkinstalldirs
move-if-change
multilib.am
README
README-maintainer-mode
setup.com
src-release.sh src-release.sh: add libbacktrace to GDB_SUPPORT_DIRS 2021-09-28 12:21:21 +01:00
symlink-tree
test-driver
ylwrap

		   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.