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Pedro Alves 0703599a49 Fix adjust_pc_after_break, remove still current thread check
On decr_pc_after_break targets, GDB adjusts the PC incorrectly if a
background single-step stops somewhere where PC-$decr_pc has a
breakpoint, and the thread that finishes the step is not the current
thread, like:

   ADDR1 nop <-- breakpoint here
   ADDR2 jmp PC

IOW, say thread A is stepping ADDR2's line in the background (an
infinite loop), and the user switches focus to thread B.  GDB's
adjust_pc_after_break logic confuses the single-step stop of thread A
for a hit of the breakpoint at ADDR1, and thus adjusts thread A's PC
to point at ADDR1 when it should not, and reports a breakpoint hit,
when thread A did not execute the instruction at ADDR1 at all.

The test added by this patch exercises exactly that.

I can't find any reason we'd need the "thread to be examined is still
the current thread" condition in adjust_pc_after_break, at least
nowadays; it might have made sense in the past.  Best just remove it,
and rely on currently_stepping().

Here's the test's log of a run with an unpatched GDB:

 35        while (1);
 (gdb) PASS: gdb.threads/step-bg-decr-pc-switch-thread.exp: next over nop
 next&
 (gdb) PASS: gdb.threads/step-bg-decr-pc-switch-thread.exp: next& over inf loop
 thread 1
 [Switching to thread 1 (Thread 0x7ffff7fc2740 (LWP 29027))](running)
 (gdb)
 PASS: gdb.threads/step-bg-decr-pc-switch-thread.exp: switch to main thread
 Breakpoint 2, thread_function (arg=0x0) at ...src/gdb/testsuite/gdb.threads/step-bg-decr-pc-switch-thread.c:34
 34        NOP; /* set breakpoint here */
 FAIL: gdb.threads/step-bg-decr-pc-switch-thread.exp: no output while stepping

gdb/ChangeLog:
2015-02-11  Pedro Alves  <pedro@codesourcery.com>

	* infrun.c (adjust_pc_after_break): Don't adjust the PC just
	because the event thread is not the current thread.

gdb/testsuite/ChangeLog:
2015-02-11  Pedro Alves  <pedro@codesourcery.com>

	* gdb.threads/step-bg-decr-pc-switch-thread.c: New file.
	* gdb.threads/step-bg-decr-pc-switch-thread.exp: New file.
2015-02-11 09:45:41 +00:00
bfd Automatic date update in version.in 2015-02-11 00:00:08 +00:00
binutils Fix memory access violations discovered by running readelf compiled with undefined memory access sanitization on fuzzed binaries. 2015-02-10 17:53:53 +00:00
config Fix --diable-shared --enable-plugins build breakage 2014-08-19 21:59:56 +09:30
cpu or1k: add missing l.msync, l.psync and l.psync instructions. 2014-07-20 20:26:09 +03:00
elfcpp This patch adds IFUNC support for arm gold backend. 2015-01-29 10:15:42 -08:00
etc PR external/{16327,16328}: Remove etc/configure.texi and etc/standards.texi. 2014-06-27 11:33:25 +02:00
gas [ARM][gas] Use as_tsktsk instead of as_warn for deprecation messages. 2015-02-09 11:20:30 +00:00
gdb Fix adjust_pc_after_break, remove still current thread check 2015-02-11 09:45:41 +00:00
gold gold/arm.cc: Output mapping symbol for PLT code 2015-02-11 15:18:59 +08:00
gprof Regenerate Makeile.in file for copyright update 2015-01-02 22:27:27 +10:30
include Recognize new DWARF5/GCC5 DW_LANG constants for Fortran 03 and Fortran 08. 2015-02-10 09:07:25 +01:00
intl
ld Initialize use_mmap 2015-02-10 19:02:07 -08:00
libdecnumber Another part of fixing "make TAGS". 2015-01-22 21:07:31 +02:00
libiberty strerror.c: Do not declare sys_nerr or sys_errlist if already macros 2015-01-19 16:29:07 +01:00
opcodes opcodes/microblaze: Rename 'or', 'and', 'xor' to avoid C++ conflict 2015-02-10 18:09:39 +00:00
readline Fix executable indicator in file name completion on Windows. 2014-12-30 21:14:25 +02:00
sim sim: Be sure of calling freeargv() after successfully call buildargv(). 2015-02-03 04:03:41 +08:00
texinfo
.cvsignore
.gitattributes Add a .gitattributes file for use with git-merge-changelog 2014-07-25 18:07:23 -04:00
.gitignore
ChangeLog FT32 initial support 2015-01-28 16:25:18 +10:30
compile Update from upstream Automake 2014-11-16 13:43:48 +01:00
config-ml.in
config.guess config.sub, config.guess: Update from upstream, to 2015-01-01 version. 2015-01-02 10:40:57 +01:00
config.rpath
config.sub config.sub, config.guess: Update from upstream, to 2015-01-01 version. 2015-01-02 10:40:57 +01:00
configure FT32 initial support 2015-01-28 16:25:18 +10:30
configure.ac FT32 initial support 2015-01-28 16:25:18 +10:30
COPYING
COPYING.LIB
COPYING.LIBGLOSS
COPYING.NEWLIB
COPYING3
COPYING3.LIB
depcomp Update from upstream Automake 2014-11-16 13:43:48 +01:00
djunpack.bat
install-sh Update from upstream Automake 2014-11-16 13:43:48 +01:00
libtool.m4 Update libtool.m4 from GCC trunk 2014-11-24 09:14:09 -08:00
ltgcc.m4
ltmain.sh PR target/59788 2014-02-06 11:01:57 +01:00
ltoptions.m4
ltsugar.m4
ltversion.m4
lt~obsolete.m4
MAINTAINERS Update description of ownership of files in include/ 2014-11-04 16:14:14 -08:00
Makefile.def [GCC bug #63539]: libgo does not use the newly built objcopy when doing a combined build 2015-01-03 14:54:45 -08:00
Makefile.in [GCC bug #63539]: libgo does not use the newly built objcopy when doing a combined build 2015-01-03 14:54:45 -08:00
Makefile.tpl [GCC bug #63539]: libgo does not use the newly built objcopy when doing a combined build 2015-01-03 14:54:45 -08:00
makefile.vms
missing Update from upstream Automake 2014-11-16 13:43:48 +01:00
mkdep
mkinstalldirs Update from upstream Automake 2014-11-16 13:43:48 +01:00
move-if-change Update `move-if-change' from gnulib 2014-11-16 17:04:02 +01:00
README
README-maintainer-mode
setup.com
src-release.sh src-release.sh: configure using --target. 2014-10-15 09:50:53 +02:00
symlink-tree
ylwrap Update from upstream Automake 2014-11-16 13:43:48 +01:00

		   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.