Aarch64: Make CPSR a 32-bit register again in the target description

This reverts commit a4d9ba85 - 'AARCH64: Change cpsr type to be
64bit.'.

Even though Linux's ptrace exposes CPSR as 64-bit, CPSR is really
32-bit, and basing GDB's fundamentals on a particular OS's ptrace(2)
implementation is a bad idea.

In addition, while that commit intended to fix big endian Aarch64, it
ended up breaking floating point debugging against GDBserver, for both
big and little endian, because it changed the CPSR to be 64-bit in the
features/aarch64-core.xml file, but missed regenerating the
regformats/aarch64.dat file.  If we generate it now, we see this:

  diff --git c/gdb/regformats/aarch64.dat w/gdb/regformats/aarch64.dat
  index afe1028..0d32183 100644
  --- c/gdb/regformats/aarch64.dat
  +++ w/gdb/regformats/aarch64.dat
  @@ -35,7 +35,7 @@ expedite:x29,sp,pc
   64:x30
   64:sp
   64:pc
  -32:cpsr
  +64:cpsr
   128:v0
   128:v1
   128:v2

IOW, that commit left regformats/aarch64.dat still considering CPSR as
32-bits.  regformats/aarch64.dat is used by GDBserver for its internal
regcache layout, and for the g/G packet register block.  See the
generated aarch64.c file in GDBserver's build dir.

So the target description xml file that GDBserver reports to GDB is
now claiming that CPSR is 64-bit, but what GDBserver actually puts in
the g/G register packets is 32-bits.  Because GDB thinks CPSR is
64-bit (because that's what the XML description says), GDB will be
reading the remaining 32-bit bits of CPSR out of v0 (the register
immediately afterwards), and then all the registers that follow CPSR
in the register packet end up wrong in GDB, because they're being read
from the wrong offsets...

gdb/
2014-10-01  Pedro Alves  <palves@redhat.com>

	* features/aarch64-core.xml (cpsr): Change back to 32-bit.
	* features/aarch64.c: Regenerate.
Fix features/i386/64bit-avx512.xml

This file's format is invalid, as it's missing some end quotes.

I noticed this because I tried to regenerate all the .dat files in
gdb/regformats/.  I got:

    sh ../../move-if-change ../regformats/i386/x32-avx.tmp ../regformats/i386/x32-avx.dat
    echo "# DO NOT EDIT: generated from i386/x32-avx512.xml" > ../regformats/i386/x32-avx512.tmp
    echo "name:`echo x32-avx512 | sed 's/-/_/g'`" >> ../regformats/i386/x32-avx512.tmp
    echo "xmltarget:x32-avx512.xml" >> ../regformats/i386/x32-avx512.tmp
    echo "expedite:rbp,rsp,rip" \
      >> ../regformats/i386/x32-avx512.tmp
    xsltproc --path "/home/pedro/gdb/mygit/src/gdb/features" --xinclude number-regs.xsl i386/x32-avx512.xml | \
      xsltproc sort-regs.xsl - | \
      xsltproc gdbserver-regs.xsl - >> ../regformats/i386/x32-avx512.tmp
    i386/64bit-avx512.xml:81: parser error : Unescaped '<' not allowed in attributes values
      <reg name="zmm11h" bitsize="256" type="v2ui128/>
      ^
    i386/64bit-avx512.xml:81: parser error : attributes construct error
      <reg name="zmm11h" bitsize="256" type="v2ui128/>
      ^
    i386/64bit-avx512.xml:81: parser error : Couldn't find end of Start Tag reg line 80
      <reg name="zmm11h" bitsize="256" type="v2ui128/>
      ^
    i386/64bit-avx512.xml:82: parser error : Unescaped '<' not allowed in attributes values
      <reg name="zmm12h" bitsize="256" type="v2ui128/>
      ^
    i386/64bit-avx512.xml:82: parser error : attributes construct error
      <reg name="zmm12h" bitsize="256" type="v2ui128/>
      ^
...
    i386/x32-avx512.xml:17: element include: XInclude error : could not load i386/64bit-avx512.xml, and no fallback was found
    -:1: parser error : Document is empty

    ^
    -:1: parser error : Start tag expected, '<' not found

    ^
    unable to parse -
    -:1: parser error : Document is empty

    ^
    -:1: parser error : Start tag expected, '<' not found

    ^
    unable to parse -
    make: *** [../regformats/i386/x32-avx512.dat] Error 6

Interestingly, gdb/expat manages to grok the broken file.

gdb/
2014-10-01  Pedro Alves  <palves@redhat.com>

	* features/i386/64bit-avx512.xml (zmm10h, zmm11h, zmm12h, zmm13h)
	(zmm14h): Add missing end quotes.
features/Makefile: Add a "clean" rule.

So that we can do "make clean all" to regenerate all the renerated
.dat files.

gdb/
2014-10-01  Pedro Alves  <palves@redhat.com>

	* features/Makefile (clean): New rule.
gdb/regformats: Don't build .dat files that aren't used by GDBserver

The only reason .dat files exist is for GBBserver to use them in its
build system.

A few .dat files are listed as targets for generation that shouldn't.
The target descriptions these files are built from aren't used by
GDBserver.  They're fallback descriptions GDB itself has baked in.

Remove them from the list of .dat files to be generated, otherwise a
plain "make" under src/gdb/features/ generates new .dat files that
aren't even in the tree today.

gdb/
2014-10-01  Pedro Alves  <palves@redhat.com>

	* features/Makefile (WHICH): Remove arm-with-m,
	arm-with-m-fpa-layout and arm-with-m-vfp-d16.
Regenerate AVX512 target description C files

I regenerated all the .c files under src/gdb/features/ and this is
what I got.

gdb/
2014-10-01  Pedro Alves  <palves@redhat.com>

	* features/i386/amd64-avx512-linux.c: Regenerate.
	* features/i386/amd64-avx512.c: Regenerate.
	* features/i386/x32-avx512-linux.c: Regenerate.
	* features/i386/x32-avx512.c: Regenerate.
features/Makefile: Make 'make cfiles' default to generating all C files

This makes it easier to rebuild all GDB's generated target description
C files.

It also clarifies the comments a bit.  One might think we need a GDB
configured for the particular arquitecture (--target=foo).  But a
build that includes support for the target description is sufficient.
(GDB rejects target descriptions that explicitly specify the
architecture, with an <architecture> element, if the architecture is
unknown.)

Tested that "make clean-cfiles" deletes all .c files under
src/gdb/features/, and that "make cfiles" generates them all without
error, and that diffing the newly generated C files against master
comes out an empty diff.

gdb/
2014-10-01  Pedro Alves  <palves@redhat.com>

	* features/Makefile: Update comments.
	(XMLTOC): List all xml files we build C files from.
	(clean-cfiles): New rule.
Add read-only markers to generated gdb/regformats/ .dat files

We have read-only markers in most generated sources already, so that
Emacs/Vi users won't edit them accidentally, but were missing them on
the generated gdb/regformats/ .dat files.

gdb/
2014-10-01  Pedro Alves  <palves@redhat.com>

	* features/Makefile ($(outdir)/%.dat): Output "THIS FILE IS
	GENERATED" along with emacs/vi read-only markers.
	* regformats/aarch64.dat: Regenerate.
	* regformats/arm-with-iwmmxt.dat: Regenerate.
	* regformats/arm-with-neon.dat: Regenerate.
	* regformats/arm-with-vfpv2.dat: Regenerate.
	* regformats/arm-with-vfpv3.dat: Regenerate.
	* regformats/i386/amd64-avx-linux.dat: Regenerate.
	* regformats/i386/amd64-avx.dat: Regenerate.
	* regformats/i386/amd64-avx512-linux.dat: Regenerate.
	* regformats/i386/amd64-avx512.dat: Regenerate.
	* regformats/i386/amd64-linux.dat: Regenerate.
	* regformats/i386/amd64-mpx-linux.dat: Regenerate.
	* regformats/i386/amd64-mpx.dat: Regenerate.
	* regformats/i386/amd64.dat: Regenerate.
	* regformats/i386/i386-avx-linux.dat: Regenerate.
	* regformats/i386/i386-avx.dat: Regenerate.
	* regformats/i386/i386-avx512-linux.dat: Regenerate.
	* regformats/i386/i386-avx512.dat: Regenerate.
	* regformats/i386/i386-linux.dat: Regenerate.
	* regformats/i386/i386-mmx-linux.dat: Regenerate.
	* regformats/i386/i386-mmx.dat: Regenerate.
	* regformats/i386/i386-mpx-linux.dat: Regenerate.
	* regformats/i386/i386-mpx.dat: Regenerate.
	* regformats/i386/i386.dat: Regenerate.
	* regformats/i386/x32-avx-linux.dat: Regenerate.
	* regformats/i386/x32-avx.dat: Regenerate.
	* regformats/i386/x32-avx512-linux.dat: Regenerate.
	* regformats/i386/x32-avx512.dat: Regenerate.
	* regformats/i386/x32-linux.dat: Regenerate.
	* regformats/i386/x32.dat: Regenerate.
	* regformats/microblaze-with-stack-protect.dat: Regenerate.
	* regformats/mips-dsp-linux.dat: Regenerate.
	* regformats/mips-linux.dat: Regenerate.
	* regformats/mips64-dsp-linux.dat: Regenerate.
	* regformats/mips64-linux.dat: Regenerate.
	* regformats/nios2-linux.dat: Regenerate.
	* regformats/rs6000/powerpc-32.dat: Regenerate.
	* regformats/rs6000/powerpc-32l.dat: Regenerate.
	* regformats/rs6000/powerpc-64l.dat: Regenerate.
	* regformats/rs6000/powerpc-altivec32l.dat: Regenerate.
	* regformats/rs6000/powerpc-altivec64l.dat: Regenerate.
	* regformats/rs6000/powerpc-cell32l.dat: Regenerate.
	* regformats/rs6000/powerpc-cell64l.dat: Regenerate.
	* regformats/rs6000/powerpc-e500l.dat: Regenerate.
	* regformats/rs6000/powerpc-vsx32l.dat: Regenerate.
	* regformats/rs6000/powerpc-vsx64l.dat: Regenerate.
	* regformats/s390-linux32.dat: Regenerate.
	* regformats/s390-linux32v1.dat: Regenerate.
	* regformats/s390-linux32v2.dat: Regenerate.
	* regformats/s390-linux64.dat: Regenerate.
	* regformats/s390-linux64v1.dat: Regenerate.
	* regformats/s390-linux64v2.dat: Regenerate.
	* regformats/s390-te-linux64.dat: Regenerate.
	* regformats/s390x-linux64.dat: Regenerate.
	* regformats/s390x-linux64v1.dat: Regenerate.
	* regformats/s390x-linux64v2.dat: Regenerate.
	* regformats/s390x-te-linux64.dat: Regenerate.
	* regformats/tic6x-c62x-linux.dat: Regenerate.
	* regformats/tic6x-c62x.dat: Regenerate.
	* regformats/tic6x-c64x-linux.dat: Regenerate.
	* regformats/tic6x-c64x.dat: Regenerate.
	* regformats/tic6x-c64xp-linux.dat: Regenerate.
	* regformats/tic6x-c64xp.dat: Regenerate.
Exit code of exited inferiors in -list-thread-groups

Don't reset the exit code at inferior exit and print it in
-list-thread-groups.

gdb/ChangeLog:

	* NEWS: Announce new exit-code field in -list-thread-groups
	output.
	* inferior.c (exit_inferior_1): Don't clear exit code.
	(inferior_appeared): Clear exit code.
	* mi/mi-main.c (print_one_inferior): Add printing of the exit
	code.

gdb/testsuite/ChangeLog:

	* gdb.mi/mi-exit-code.exp: New file.
	* gdb.mi/mi-exit-code.c: New file.

gdb/doc/ChangeLog:

	* gdb.texinfo (Miscellaneous gdb/mi Commands): Document new
	exit-code field in -list-thread-groups output.
Really fail inserting software breakpoints on read-only regions

Currently, with "set breakpoint auto-hw off", we'll still try to
insert a software breakpoint at addresses covered by supposedly
read-only or inacessible regions:

 (top-gdb) mem 0x443000 0x450000 ro
 (top-gdb) set mem inaccessible-by-default off
 (top-gdb) disassemble
 Dump of assembler code for function main:
    0x0000000000443956 <+34>:    movq   $0x0,0x10(%rax)
 => 0x000000000044395e <+42>:    movq   $0x0,0x18(%rax)
    0x0000000000443966 <+50>:    mov    -0x24(%rbp),%eax
    0x0000000000443969 <+53>:    mov    %eax,-0x20(%rbp)
 End of assembler dump.
 (top-gdb) b *0x0000000000443969
 Breakpoint 5 at 0x443969: file ../../src/gdb/gdb.c, line 29.
 (top-gdb) c
 Continuing.
 warning: cannot set software breakpoint at readonly address 0x443969

 Breakpoint 5, 0x0000000000443969 in main (argc=1, argv=0x7fffffffd918) at ../../src/gdb/gdb.c:29
 29        args.argc = argc;
 (top-gdb)

We warn, saying that the insertion can't be done, but then proceed
attempting the insertion anyway, and in case of manually added
regions, the insert actually succeeds.

This is a regression; GDB used to fail inserting the breakpoint.  More
below.

I stumbled on this as I wrote a test that manually sets up a read-only
memory region with the "mem" command, in order to test GDB's behavior
with breakpoints set on read-only regions, even when the real memory
the breakpoints are set at isn't really read-only.  I wanted that in
order to add a test that exercises software single-stepping through
read-only regions.

Note that the memory regions that target_memory_map returns aren't
like e.g., what would expect to see in /proc/PID/maps on Linux.
Instead, they're the physical memory map from the _debuggers_
perspective.  E.g., a read-only region would be real ROM or flash
memory, while a read-only+execute mapping in /proc/PID/maps is still
read-write to the debugger (otherwise the debugger wouldn't be able to
set software breakpoints in the code segment).

If one tries to manually write to memory that falls within a memory
region that is known to be read-only, with e.g., "p foo = 1", then we
hit a check in memory_xfer_partial_1 before the write mananges to make
it to the target side.

But writing a software/memory breakpoint nowadays goes through
target_write_raw_memory, and unlike when writing memory with
TARGET_OBJECT_MEMORY, nothing on the TARGET_OBJECT_RAW_MEMORY path
checks whether we're trying to write to a read-only region.

At the time "breakpoint auto-hw" was added, we didn't have the
TARGET_OBJECT_MEMORY vs TARGET_OBJECT_RAW_MEMORY target object
distinction yet, and the code path in memory_xfer_partial that blocks
writes to read-only memory was hit for memory breakpoints too.  With
GDB 6.8 we had:

 warning: cannot set software breakpoint at readonly address 0000000000443943
 Warning:
 Cannot insert breakpoint 1.
 Error accessing memory address 0x443943: Input/output error.

So I started out by fixing this by adding the memory region validation
to TARGET_OBJECT_RAW_MEMORY too.

But later, when testing against GDBserver, I realized that that would
only block software/memory breakpoints GDB itself inserts with
gdb/mem-break.c.  If a target has a to_insert_breakpoint method, the
insertion request will still pass through to the target.  So I ended
up converting the "cannot set breakpoint" warning in breakpoint.c to a
real error return, thus blocking the insertion sooner.

With that, we'll end up no longer needing the TARGET_OBJECT_RAW_MEMORY
changes once software single-step breakpoints are converted to real
breakpoints.  We need them today as software single-step breakpoints
bypass insert_bp_location.  But, it'll be best to leave that in as
safeguard anyway, for other direct uses of TARGET_OBJECT_RAW_MEMORY.

Tested on x86_64 Fedora 20, native and gdbserver.

gdb/
2014-10-01  Pedro Alves  <palves@redhat.com>

	* breakpoint.c (insert_bp_location): Error out if inserting a
	software breakpoint at a read-only address.
	* target.c (memory_xfer_check_region): New function, factored out
	from ...
	(memory_xfer_partial_1): ... this.  Make the 'reg_len' local a
	ULONGEST.
	(target_xfer_partial) <TARGET_OBJECT_RAW_MEMORY>: Check the access
	against the memory region attributes.

gdb/testsuite/
2014-10-01  Pedro Alves  <palves@redhat.com>

	* gdb.base/breakpoint-in-ro-region.c: New file.
	* gdb.base/breakpoint-in-ro-region.exp: New file.
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