mirror of
https://sourceware.org/git/binutils-gdb.git
synced 2024-12-27 04:52:05 +08:00
3a3fd0fd2c
This patch fixes an internal error exposed by a test that does something like: define kill-and-remove kill inferiors 2 remove-inferiors 2 end # Start one inferior. start # Start another inferior. add-inferior 2 inferior 2 start # Kill and remove inferior 1 while inferior 2 is selected. thread apply 1.1 kill-and-remove The internal error looks like this: Thread 1.1 (Thread 0x7ffff7fc2700 (LWP 20677)): [Switching to inferior 1 [process 20677] (gdb/testsuite/outputs/gdb.threads/threadapply/threadapply)] [Switching to thread 1.1 (Thread 0x7ffff7fc2700 (LWP 20677))] #0 main () at src/gdb/testsuite/gdb.threads/threadapply.c:38 38 for (i = 0; i < NUM; i++) src/gdb/inferior.c:66: internal-error: void set_current_inferior(inferior*): Assertion `inf != NULL' failed. A problem internal to GDB has been detected, further debugging may prove unreliable. Quit this debugging session? (y or n) FAIL: gdb.threads/threadapply.exp: kill_and_remove_inferior: try kill-and-remove: thread apply 1.1 kill-and-remove (GDB internal error) There are several problems around this area of the code. One is that in do_restore_current_thread_cleanup, we do a look up of inferior by ptid, which can find the wrong inferior if the previously selected inferior exited and some other inferior was started with a reused pid (rare, but still...). The other problem is that the "remove-inferiors" command rejects attempts to remove the current inferior, but when we get to "remove-inferiors" in a "thread apply THR remove-inferiors 2" command, the current inferior is the inferior of thread THR, not the previously selected inferior, so if the previously selected inferior was inferior 2, that command still manages to wipe it, and then gdb restores the old selected inferior, which is now a dangling pointer... So the fix here is: - Make make_cleanup_restore_current_thread store a pointer to the previously selected inferior directly, and use it directly instead of doing ptid look ups. - Add a refcount to inferiors, very similar to thread_info's refcount, that is incremented/decremented by make_cleanup_restore_current_thread, and checked before deleting an inferior. To avoid duplication, a new refcounted_object type is added, that both thread_info and inferior inherit from. gdb/ChangeLog: 2017-04-19 Pedro Alves <palves@redhat.com> * common/refcounted-object.h: New file. * gdbthread.h: Include "common/refcounted-object.h". (thread_info): Inherit from refcounted_object and add comments. (thread_info::incref, thread_info::decref) (thread_info::m_refcount): Delete. (thread_info::deletable): Use the refcounted_object::refcount() method. * inferior.c (current_inferior_): Add comment. (set_current_inferior): Increment/decrement refcounts. (prune_inferiors, remove_inferior_command): Skip inferiors marked not-deletable instead of comparing with the current inferior. (initialize_inferiors): Increment the initial inferior's refcount. * inferior.h (struct inferior): Forward declare. Include "common/refcounted-object.h". (current_inferior, set_current_inferior): Move declaration to before struct inferior's definition, and fix comment. (inferior): Inherit from refcounted_object. Add comments. * thread.c (switch_to_thread_no_regs): Reference the thread's inferior pointer directly instead of doing a ptid lookup. (switch_to_no_thread): New function. (switch_to_thread(thread_info *)): New function, factored out from ... (switch_to_thread(ptid_t)): ... this. (restore_current_thread): Delete. (current_thread_cleanup): Remove 'inf_id' and 'was_removable' fields, and add 'inf' field. (do_restore_current_thread_cleanup): Check whether old->inf is alive instead of looking up an inferior by ptid. Use switch_to_thread and switch_to_no_thread. (restore_current_thread_cleanup_dtor): Use old->inf directly instead of lookup up an inferior by id. Decref the inferior. Don't restore 'removable'. (make_cleanup_restore_current_thread): Same the inferior pointer in old, instead of the inferior number. Incref the inferior. Don't save/clear 'removable'. gdb/testsuite/ChangeLog: 2017-04-19 Pedro Alves <palves@redhat.com> * gdb.threads/threadapply.exp (kill_and_remove_inferior): New procedure. (top level): Call it. * lib/gdb.exp (gdb_define_cmd): New procedure. |
||
---|---|---|
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 | ||
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 | ||
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.