Binutils with MCST patches
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Sandra Loosemore f489207efd Fix stepping past unwritable kernel helper on nios2-linux-gnu.
This patch fixes a problem on nios2-linux-gnu with stepping past the
kernel helper __kuser_cmpxchg, which was exposed by the testcase
gdb.threads/watchpoint-fork.exp.  The kernel maps this function into
user space on an unwritable page.  In this testcase, the cmpxchg
helper is invoked indirectly from the setbuf call in the test program.
Since this target lacks hardware breakpoint/watchpoint support, GDB
tries to single-step through the program by setting software
breakpoints, and was just giving an error when it reached the function
on the unwritable page.

The solution here is to always step over the call instead of stepping
into it; cmpxchg is supposed to be an atomic operation so this
behavior seems reasonable.  The hook in nios2_get_next_pc is somewhat
generic, but at present cmpxchg is the only helper provided by the
Linux kernel that is invoked by an ordinary function call.  (Signal
return trampolines also go through the unwritable page but not by a
function call.)

Fixing this issue also revealed that the testcase needs a much larger
timeout factor when software single-stepping is used.  That has also
been fixed in this patch.

gdb/ChangeLog

2019-03-28  Sandra Loosemore  <sandra@codesourcery.com>

        * nios2-tdep.h (struct gdbarch_tdep): Add is_kernel_helper.
        * nios2-tdep.c (nios2_get_next_pc): Skip over kernel helpers.
        * nios2-linux-tdep.c (nios2_linux_is_kernel_helper): New.
        (nios2_linux_init_abi): Install it.

gdb/testsuite/ChangeLog

2019-03-28  Sandra Loosemore  <sandra@codesourcery.com>

        * gdb.threads/watchpoint-fork.exp (test): Use large timeout
        factor when no hardware watchpoint support.
2019-03-28 09:29:22 -07:00
bfd PR24392, Clang warning Wtautological-constant-out-of-range-compare 2019-03-28 17:10:31 +10:30
binutils AArch64/Arm: Update testcases fixing endiannes and linux targets 2019-03-26 16:47:14 +00:00
config
contrib
cpu
elfcpp
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gas PR24390, Don't decode mtfsb field as a cr field 2019-03-28 15:21:05 +10:30
gdb Fix stepping past unwritable kernel helper on nios2-linux-gnu. 2019-03-28 09:29:22 -07:00
gold
gprof
include PR24390, Don't decode mtfsb field as a cr field 2019-03-28 15:21:05 +10:30
intl
ld Provide string description of definition, visibility and resolution in LTO plug-in. 2019-03-26 15:22:01 +01:00
libdecnumber
libiberty
opcodes PR24390, Don't decode mtfsb field as a cr field 2019-03-28 15:21:05 +10:30
readline
sim sim: fix aarch64 sim build 2019-03-28 13:46:09 +00:00
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		   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.