No description
c06cbd92be
Nowadays, when --wrapper is used, GDBserver skips extra traps/stops in the wrapper program, and stops at the first instruction of the program to be debugged. However, GDBserver created target description in the first stop of inferior, and the executable of the inferior is the wrapper program rather than the program to be debugged. In this way, the target description can be wrong if the architectures of wrapper program and program to be debugged are different. This is shown by some fails in gdb.server/wrapper.exp on buildbot. We are testing i686-linux GDB (Fedora-i686) on an x86_64-linux box (fedora-x86-64-4) in buildbot, such configuration causes fails in gdb.server/wrapper.exp like this: spawn /home/gdb-buildbot-2/fedora-x86-64-4/fedora-i686/build/gdb/testsuite/../../gdb/gdbserver/gdbserver --once --wrapper env TEST=1 -- :2346 /home/gdb-buildbot-2/fedora-x86-64-4/fedora-i686/build/gdb/testsuite/outputs/gdb.server/wrapper/wrapper Process /home/gdb-buildbot-2/fedora-x86-64-4/fedora-i686/build/gdb/testsuite/outputs/gdb.server/wrapper/wrapper created; pid = 8795 Can't debug 64-bit process with 32-bit GDBserver Exiting target remote localhost:2346 localhost:2346: Connection timed out. (gdb) FAIL: gdb.server/wrapper.exp: setting breakpoint at marker See https://sourceware.org/ml/gdb-testers/2015-q3/msg01541.html In this case, program to be debugged ("wrapper") is 32-bit but wrapper program ("/usr/bin/env") is 64-bit, so GDBserver gets the 64-bit target description instead of 32-bit. The root cause of this problem is that GDBserver creates target description too early, and the rationale of fix could be creating target description once the GDBserver skips extra traps and inferior stops at the first instruction of the program we want to debug. IOW, when GDBserver skips extra traps, the inferior's tdesc is NULL, and mywait and its callees shouldn't use inferior's tdesc, so in this patch, we skip code that requires register access, see changes in linux_resume_one_lwp_throw and need_step_over_p. In linux_low_filter_event, if target description isn't initialised and GDBserver attached the process, we create target description immediately, because GDBserver don't have to skip extra traps for attach, IOW, it makes no sense to use --attach and --wrapper together. Otherwise, the process is launched by GDBserver, we keep the status pending, and return. After GDBserver skipped extra traps in start_inferior, we call a target_ops hook arch_setup to initialise target description there. gdb/gdbserver: 2015-07-24 Yao Qi <yao.qi@linaro.org> * linux-low.c (linux_arch_setup): New function. (linux_low_filter_event): If proc->tdesc is NULL and proc->attached is true, call the_low_target.arch_setup. Otherwise, keep status pending, and return. (linux_resume_one_lwp_throw): Don't call get_pc if thread->while_stepping isn't NULL. Don't call get_thread_regcache if proc->tdesc is NULL. (need_step_over_p): Return 0 if proc->tdesc is NULL. (linux_target_ops): Install arch_setup. * server.c (start_inferior): Call the_target->arch_setup. * target.h (struct target_ops) <arch_setup>: New field. (target_arch_setup): New marco. * lynx-low.c (lynx_target_ops): Update. * nto-low.c (nto_target_ops): Update. * spu-low.c (spu_target_ops): Update. * win32-low.c (win32_target_ops): Update. |
||
---|---|---|
bfd | ||
binutils | ||
config | ||
cpu | ||
elfcpp | ||
etc | ||
gas | ||
gdb | ||
gold | ||
gprof | ||
include | ||
intl | ||
ld | ||
libdecnumber | ||
libiberty | ||
opcodes | ||
readline | ||
sim | ||
texinfo | ||
zlib | ||
.cvsignore | ||
.gitattributes | ||
.gitignore | ||
ChangeLog | ||
compile | ||
config-ml.in | ||
config.guess | ||
config.rpath | ||
config.sub | ||
configure | ||
configure.ac | ||
COPYING | ||
COPYING.LIB | ||
COPYING.LIBGLOSS | ||
COPYING.NEWLIB | ||
COPYING3 | ||
COPYING3.LIB | ||
depcomp | ||
djunpack.bat | ||
install-sh | ||
libtool.m4 | ||
ltgcc.m4 | ||
ltmain.sh | ||
ltoptions.m4 | ||
ltsugar.m4 | ||
ltversion.m4 | ||
lt~obsolete.m4 | ||
MAINTAINERS | ||
Makefile.def | ||
Makefile.in | ||
Makefile.tpl | ||
makefile.vms | ||
missing | ||
mkdep | ||
mkinstalldirs | ||
move-if-change | ||
README | ||
README-maintainer-mode | ||
setup.com | ||
src-release.sh | ||
symlink-tree | ||
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.