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Pedro Alves 31445d1036 GDBserver: Don't assume a current process in D;PID implementation (PR gdb/23377)
This fixes a gdb.base/multi-forks.exp regression with GDBserver.

Git commit f2ffa92bbc ("gdb: Eliminate the 'stop_pc' global") caused
the regression by exposing a latent bug in gdbserver.

The bug is that GDBserver's implementation of the D;PID packet
incorrectly assumes that the selected thread points to the process
being detached.  This happens via the any_persistent_commands call,
which calls current_process:

  (gdb) bt
  #0  0x000000000040a57e in internal_error(char const*, int, char const*, ...)
  (file=0x4a53c0 "src/gdb/gdbserver/inferiors.c", line=212, fmt=0x4a539e "%s:
  Assertion `%s' failed.") at src/gdb/gdbserver/../common/errors.c:54
  #1  0x0000000000420acf in current_process() () at
  src/gdb/gdbserver/inferiors.c:212
  #2  0x00000000004226a0 in any_persistent_commands() () at
  gdb/gdbserver/mem-break.c:308
  #3  0x000000000042cb43 in handle_detach(char*) (own_buf=0x6f0280 "D;62ea") at
  src/gdb/gdbserver/server.c:1210
  #4  0x0000000000433af3 in process_serial_event() () at
  src/gdb/gdbserver/server.c:4055
  #5  0x0000000000434878 in handle_serial_event(int, void*) (err=0,
  client_data=0x0)

The "eliminate stop_pc" commit exposes the problem because before that
commit, GDB's switch_to_thread always read the newly-selected thread's
PC, and that would end up forcing GDBserver's selected thread to
change accordingly as side effect.  After that commit, GDB no longer
reads the thread's PC, and GDBserver does not switch the thread.

Fix this by removing the assumption from GDBserver.

gdb/gdbserver/ChangeLog:
2018-07-11  Pedro Alves  <palves@redhat.com>

	PR gdb/23377
	* mem-break.c (any_persistent_commands): Add process_info
	parameter and use it instead of relying on the current process.
	Change return type to bool.
	* mem-break.h (any_persistent_commands): Add process_info
	parameter and change return type to bool.
	* server.c (handle_detach): Remove require_running_or_return call.
	Look up the process_info for the process we're about to detach.
	If not found, return back error to GDB.  Adjust
	any_persistent_commands call to pass down a process pointer.
2018-07-11 23:31:44 +01:00
bfd MIPS/BFD: Fix TLS relocation resolution for regular executables 2018-07-11 17:44:45 +01:00
binutils xgate testsuite fixes 2018-07-10 23:59:59 +09:30
config Bump to autoconf 2.69 and automake 1.15.1 2018-06-19 16:55:06 -04:00
cpu PR22069, Several instances of register accidentally spelled as regsiter 2018-05-09 15:55:28 +09:30
elfcpp [GOLD] PowerPC .gnu.attributes support 2018-07-06 15:18:51 +09:30
etc Bump to autoconf 2.69 and automake 1.15.1 2018-06-19 16:55:06 -04:00
gas Adds the speculation barrier instructions to the ARM assembler and disassembler. 2018-07-11 18:05:34 +01:00
gdb GDBserver: Don't assume a current process in D;PID implementation (PR gdb/23377) 2018-07-11 23:31:44 +01:00
gold Fix printing the size of GOLD's memory areana on Cygwin based systems. 2018-07-11 08:39:36 -07:00
gprof Fix use of "command line X" in binutils doc 2018-07-02 11:18:24 +01:00
include Fix diagnostic errors 2018-07-06 15:18:59 +09:30
intl Bump to autoconf 2.69 and automake 1.15.1 2018-06-19 16:55:06 -04:00
ld MIPS/BFD: Fix TLS relocation resolution for regular executables 2018-07-11 17:44:45 +01:00
libdecnumber Bump to autoconf 2.69 and automake 1.15.1 2018-06-19 16:55:06 -04:00
libiberty Bump to autoconf 2.69 and automake 1.15.1 2018-06-19 16:55:06 -04:00
opcodes Adds the speculation barrier instructions to the ARM assembler and disassembler. 2018-07-11 18:05:34 +01:00
readline Bump to autoconf 2.69 and automake 1.15.1 2018-06-19 16:55:06 -04:00
sim Bump to autoconf 2.69 and automake 1.15.1 2018-06-19 16:55:06 -04:00
texinfo
zlib Regen doc/Makefile.in 2018-06-21 23:00:05 +09:30
.cvsignore
.gitattributes
.gitignore
ar-lib Bump to autoconf 2.69 and automake 1.15.1 2018-06-19 16:55:06 -04:00
ChangeLog Update config.sub 2018-07-06 08:23:40 +02:00
compile
config-ml.in Update top level configure files by synchronizing them with gcc. 2018-01-10 15:29:21 +00:00
config.guess Update config.guess and config.sub 2018-07-05 13:35:19 +02:00
config.rpath
config.sub Update config.sub 2018-07-06 08:23:40 +02:00
configure Introduce @unless/@endunless and postbootstrap Makefile targets 2018-06-29 23:49:28 -03:00
configure.ac Introduce @unless/@endunless and postbootstrap Makefile targets 2018-06-29 23:49:28 -03:00
COPYING
COPYING3
COPYING3.LIB
COPYING.LIB
COPYING.LIBGLOSS Update the address of the FSF in the copyright notice of files which were using the old address. 2017-12-14 12:48:55 +00:00
COPYING.NEWLIB
depcomp
djunpack.bat
install-sh
libtool.m4 Bump to autoconf 2.69 and automake 1.15.1 2018-06-19 16:55:06 -04:00
lt~obsolete.m4
ltgcc.m4
ltmain.sh
ltoptions.m4
ltsugar.m4
ltversion.m4
MAINTAINERS
Makefile.def This was already applied on the GCC side. 2018-06-19 00:05:40 +02:00
Makefile.in Introduce @unless/@endunless and postbootstrap Makefile targets 2018-06-29 23:49:28 -03:00
Makefile.tpl Introduce @unless/@endunless and postbootstrap Makefile targets 2018-06-29 23:49:28 -03:00
makefile.vms
missing
mkdep
mkinstalldirs
move-if-change
README
README-maintainer-mode Bump to autoconf 2.69 and automake 1.15.1 2018-06-19 16:55:06 -04:00
setup.com
src-release.sh Improve junk file removal in source tarball creation script. 2018-01-30 17:48:24 +00:00
symlink-tree
test-driver Bump to autoconf 2.69 and automake 1.15.1 2018-06-19 16:55:06 -04:00
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.