Binutils with MCST patches
65d2b333a8
When running under valgrind, multi-arch-exec.exp blocks forever.
Some (painful) investigation shows this is due to valgrind slowing
down GDB, and GDB has to output some messages at a different time,
when GDB does not have the terminal for output.
To reproduce the problem, you need to slow down GDB.
It can be reproduced by:
cd gdb/testsuite/outputs/gdb.multi/multi-arch-exec/
../../../../gdb -ex 'set debug lin-lwp 1' -ex 'break all_started' -ex 'run' ./2-multi-arch-exec
The above stops at a breakpoint. Do continue.
GDB is then suspended because of SIGTTOU.
The stacktrace that leads to the hanging GDB is:
(top-gdb) bt
at ../../binutils-gdb/gdb/exceptions.c:130
....
Alternatively, the same happens when doing
strace -o s.out ../../../../gdb -ex 'break all_started' -ex 'run' ./2-multi-arch-exec
And of course, valgrind is also sufficiently slowing down GDB to
reproduce this :).
Fix this by calling target_terminal::ours_for_output ();
at the beginning of follow_exec.
Note that all this terminal handling is not very clear to me:
* Some code takes the terminal, and then takes care to give it back to the inferior
if the terminal was belonging to the inferior.
(e.g. annotate_breakpoints_invalid).
* some code takes the terminal, but does not give it back
(e.g. update_inserted_breakpoint_locations).
* some code takes it, and unconditionally gives it back
(e.g. handle_jit_event)
* here and there, we also find
gdb::optional<target_terminal::scoped_restore_terminal_state> term_state;
before a (sometimes optional) call to ours_for_output.
And such calls to ours_for_output is sometimes protected by:
if (target_supports_terminal_ours ())
(e.g. exceptions.c: print_flush).
but most of the code calls it without checking if the target supports it.
* some code is outputting some errors, but only takes the terminal
after. E.g. infcmd.c: prepare_one_step
gdb/ChangeLog
2019-03-28 Philippe Waroquiers <philippe.waroquiers@skynet.be>
* infrun.c (follow_exec): Call target_terminal::ours_for_output.
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| bfd | ||
| binutils | ||
| config | ||
| contrib | ||
| cpu | ||
| elfcpp | ||
| etc | ||
| gas | ||
| gdb | ||
| gold | ||
| gprof | ||
| include | ||
| intl | ||
| ld | ||
| libdecnumber | ||
| libiberty | ||
| opcodes | ||
| readline | ||
| sim | ||
| texinfo | ||
| zlib | ||
| .cvsignore | ||
| .gitattributes | ||
| .gitignore | ||
| ar-lib | ||
| ChangeLog | ||
| compile | ||
| config-ml.in | ||
| config.guess | ||
| config.rpath | ||
| config.sub | ||
| configure | ||
| configure.ac | ||
| COPYING | ||
| COPYING3 | ||
| COPYING3.LIB | ||
| COPYING.LIB | ||
| COPYING.LIBGLOSS | ||
| COPYING.NEWLIB | ||
| depcomp | ||
| djunpack.bat | ||
| install-sh | ||
| libtool.m4 | ||
| lt~obsolete.m4 | ||
| ltgcc.m4 | ||
| ltmain.sh | ||
| ltoptions.m4 | ||
| ltsugar.m4 | ||
| ltversion.m4 | ||
| MAINTAINERS | ||
| Makefile.def | ||
| Makefile.in | ||
| Makefile.tpl | ||
| makefile.vms | ||
| missing | ||
| mkdep | ||
| mkinstalldirs | ||
| move-if-change | ||
| multilib.am | ||
| README | ||
| README-maintainer-mode | ||
| setup.com | ||
| src-release.sh | ||
| 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.