mirror of
https://sourceware.org/git/binutils-gdb.git
synced 2025-01-06 12:09:26 +08:00
56f4dea207
While testing a WIP Cygwin GDB that supports non-stop, I noticed that gdb.threads/attach-non-stop.exp exposes that this: (gdb) attach PID& ... (gdb) detach ... hangs. And it turns out that it hangs in all-stop as well. This commits fixes that. After "attach &", the target is set running, we've called ContinueDebugEvent and the process_thread thread is waiting for WaitForDebugEvent events. It is the equivalent of "attach; c&". In windows_nat_target::detach, the first thing we do is unconditionally call windows_continue (for ContinueDebugEvent), which blocks in do_synchronously, until the process_thread sees an event out of WaitForDebugEvent. Unless the inferior happens to run into a breakpoint, etc., then this hangs indefinitely. If we've already called ContinueDebugEvent earlier, then we shouldn't be calling it again in ::detach. Still in windows_nat_target::detach, we have an interesting issue that ends up being the bulk of the patch -- only the process_thread thread can call DebugActiveProcessStop, but if it is blocked in WaitForDebugEvent, we need to somehow force it to break out of it. The only way to do that, is to force the inferior to do something that causes WaitForDebugEvent to return some event. This patch uses CreateRemoteThread to do it, which results in WaitForDebugEvent reporting CREATE_THREAD_DEBUG_EVENT. We then terminate the injected thread before it has a chance to run any userspace code. Note that Win32 functions like DebugBreakProcess and GenerateConsoleCtrlEvent would also inject a new thread in the inferior. I first used DebugBreakProcess, but that is actually more complicated to use, because we'd have to be sure to consume the breakpoint event before detaching, otherwise the inferior would likely die due a breakpoint exception being raised with no debugger around to intercept it. See the new break_out_process_thread method. So the fix has two parts: - Keep track of whether we've called ContinueDebugEvent and the process_thread thread is waiting for events, or whether WaitForDebugEvent already returned an event. - In windows_nat_target::detach, if the process_thread thread is waiting for events, unblock out of its WaitForDebugEvent, before proceeding with the actual detach. New test included. Passes cleanly on GNU/Linux native and gdbserver, and also passes cleanly on Cygwin and MinGW, with the fix. Before the fix, it would hang and fail with a timeout. Tested-By: Hannes Domani <ssbssa@yahoo.de> Reviewed-By: Tom Tromey <tom@tromey.com> Change-Id: Ifb91c58c08af1a9bcbafecedc93dfce001040905 |
||
---|---|---|
bfd | ||
binutils | ||
config | ||
contrib | ||
cpu | ||
elfcpp | ||
etc | ||
gas | ||
gdb | ||
gdbserver | ||
gdbsupport | ||
gnulib | ||
gold | ||
gprof | ||
gprofng | ||
include | ||
ld | ||
libbacktrace | ||
libctf | ||
libdecnumber | ||
libiberty | ||
libsframe | ||
opcodes | ||
readline | ||
sim | ||
texinfo | ||
zlib | ||
.cvsignore | ||
.editorconfig | ||
.gitattributes | ||
.gitignore | ||
.pre-commit-config.yaml | ||
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 | ||
SECURITY.txt | ||
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.