Go to file
Pedro Alves e7bc9db8f4 Don't touch frame_info objects if frame cache was reinitialized
This fixes yet another bug exposed by ASAN + multi-target.exp

Running an Asan-enabled GDB against gdb.multi/multi-target.exp exposed
yet another latent GDB bug.  See here for the full log:

  https://sourceware.org/pipermail/gdb-patches/2020-July/170761.html

As Simon described, the problem is:

 - We create a new frame_info object in restore_selected_frame (by
   calling find_relative_frame)

 - The frame is allocated on the frame_cache_obstack

 - In frame_unwind_try_unwinder, we try to find an unwinder for that
   frame

 - While trying unwinders, memory read fails because the remote target
   closes, because of "monitor exit"

 - That calls reinit_frame_cache (as shown above), which resets
   frame_cache_obstack

 - When handling the exception in frame_unwind_try_unwinder, we try to
   set some things on the frame_info object (like *this_cache, which
   in fact tries to write into frame_info::prologue_cache), but the
   frame_info object is no more, it went away with the obstack.

Fix this by maintaining a frame cache generation counter.  Then in
exception handling code paths, don't touch frame objects if the
generation is not the same as it was on entry.

This commit generalizes the gdb.server/server-kill.exp testcase and
reuses it to test the scenario in question.  The new tests fail
without the GDB fix.

gdb/ChangeLog:

	* frame-unwind.c (frame_unwind_try_unwinder): On exception, don't
	touch THIS_CACHE/THIS_FRAME if the frame cache was cleared
	meanwhile.
	* frame.c (frame_cache_generation, get_frame_cache_generation):
	New.
	(reinit_frame_cache): Increment FRAME_CACHE_GENERATION.
	(get_prev_frame_if_no_cycle): On exception, don't touch
	PREV_FRAME/THIS_FRAME if the frame cache was cleared meanwhile.
	* frame.h (get_frame_cache_generation): Declare.

gdb/testsuite/ChangeLog:

	* gdb.server/server-kill.exp (prepare): New, factored out from the
	top level.
	(kill_server): New.
	(test_tstatus, test_unwind_nosyms, test_unwind_syms): New.
	(top level) : Call test_tstatus, test_unwind_nosyms, test_unwind_syms.
2020-07-23 16:29:28 +01:00
bfd Automatic date update in version.in 2020-07-23 00:00:08 +00:00
binutils binutils, testsuite: allow compilation before doing run_dump_test 2020-07-22 18:03:57 +01:00
config Add markers for binutils 2.35 branch 2020-07-04 10:16:22 +01:00
contrib
cpu Add markers for binutils 2.35 branch 2020-07-04 10:16:22 +01:00
elfcpp Add markers for binutils 2.35 branch 2020-07-04 10:16:22 +01:00
etc
gas MIPS/GAS/testsuite: Fix JALR relocation tests for IRIX targets 2020-07-22 12:46:00 +01:00
gdb Don't touch frame_info objects if frame cache was reinitialized 2020-07-23 16:29:28 +01:00
gdbserver gdbserver: handle running threads in qXfer:threads:read 2020-07-22 12:32:53 +01:00
gdbsupport gdb/riscv: delete target descriptions when gdb exits 2020-07-17 21:15:32 +01:00
gnulib
gold gold: Update x32 test 2020-07-19 07:30:42 -07:00
gprof Update Turkish translation in the gprof sub-directory 2020-07-09 14:25:11 +01:00
include libctf, link: tie in the deduplicating linker 2020-07-22 18:02:19 +01:00
intl
ld ld, testsuite: do not run CTF tests at all on non-ELF for now 2020-07-22 18:05:32 +01:00
libctf libctf: fixes for systems on which sizeof (void *) > sizeof (long) 2020-07-22 18:05:32 +01:00
libdecnumber
libiberty
opcodes Revert "x86: Don't display eiz with no scale" 2020-07-21 14:20:11 +02:00
readline Update readline/README to mention patchlevel 2020-06-30 15:17:07 -06:00
sim sim/igen: Fix linker error with -fno-common 2020-07-03 21:03:47 +02:00
texinfo
zlib
.cvsignore
.gitattributes
.gitignore
ar-lib
ChangeLog Add markers for binutils 2.35 branch 2020-07-04 10:16:22 +01:00
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.