First cut at adding arm64 Linux / Android support to Breakpad.

First cut at adding arm64 Linux / Android support to Breakpad.

This is an initial attempt to add Arm64 (aarch64) support to Breakpad for
Linux / Android platforms.  This CL adds the Arm64 data structures, but does
not yet implement the Android getcontext support or CPUFillFromThreadInfo /
CPUFillFromUContext.

BUG=354405,335641
R=mark@chromium.org

Committed: 1301

[rmcilroy]

Mark: This is a first go at implementing arm64 support for Breakpad on Android /
Linux clients.  I've only implemented the data-structure definitions in this CL,
I've not yet implemented Android getcontext support or CPUFillFromThreadInfo /
CPUFillFromUContext for arm64.  If this CL seems to be going in the right
direction I can implement those either in the same CL or a different CL as you
prefer?

To build, this requires arm64 support in inux_syscall_support.h - I have another
CL at https://codereview.chromium.org/220933002/ which implements the necessary
support.

PTAL.

https://breakpad.appspot.com/1354002/diff/1/client/linux/minidump_writer/linu...
File client/linux/minidump_writer/linux_ptrace_dumper.cc (right):

https://breakpad.appspot.com/1354002/diff/1/client/linux/minidump_writer/linu...
client/linux/minidump_writer/linux_ptrace_dumper.cc:204: }
PTRACE_GETREGS isn't defined for aarch64.  The new way of making the call
involves using PTRACE_GETREGSET.

[Mark Mentovai]

This is going in the right direction. I think I’d prefer to see this change be
limited to what it currently does, and then a follow-up (or follow-ups) to
implement the TODOs you’re leaving behind. Bite-sized pieces.

https://breakpad.appspot.com/1354002/diff/20001/client/linux/minidump_writer/...
File client/linux/minidump_writer/linux_ptrace_dumper.cc (right):

https://breakpad.appspot.com/1354002/diff/20001/client/linux/minidump_writer/...
client/linux/minidump_writer/linux_ptrace_dumper.cc:197: if
(sys_ptrace(PTRACE_GETREGSET, tid, (void*)NT_PRSTATUS, (void*)&io) == -1) {
Would this work for any other architectures?

https://breakpad.appspot.com/1354002/diff/20001/common/android/include/elf.h
File common/android/include/elf.h (right):

https://breakpad.appspot.com/1354002/diff/20001/common/android/include/elf.h#...
common/android/include/elf.h:60: #if !defined(ELFSIZE) && defined(ARCH_ELFSIZE)
Did you take the changes to these files in common/android/include from the
upstream files?

https://breakpad.appspot.com/1354002/diff/20001/common/android/ucontext_const...
File common/android/ucontext_constants.h (right):

https://breakpad.appspot.com/1354002/diff/20001/common/android/ucontext_const...
common/android/ucontext_constants.h:50: #define  MCONTEXT_GREGS_OFFSET     48
Why aren’t these using offsetof?

https://breakpad.appspot.com/1354002/diff/20001/common/memory.h
File common/memory.h (right):

https://breakpad.appspot.com/1354002/diff/20001/common/memory.h#newcode113
common/memory.h:113: #if defined(__x86_64) || defined(__aarch64__)
x86_64 is normally spelled in our codebase with the __ on both ends: __x86_64__.

[rmcilroy]

https://breakpad.appspot.com/1354002/diff/20001/client/linux/minidump_writer/...
File client/linux/minidump_writer/linux_ptrace_dumper.cc (right):

https://breakpad.appspot.com/1354002/diff/20001/client/linux/minidump_writer/...
client/linux/minidump_writer/linux_ptrace_dumper.cc:197: if
(sys_ptrace(PTRACE_GETREGSET, tid, (void*)NT_PRSTATUS, (void*)&io) == -1) {
On 2014/04/01 19:13:32, Mark Mentovai wrote:
> Would this work for any other architectures?

It does work on my Linux desktop, and according to
http://www.cygwin.com/ml/archer/2010-q3/msg00193.html it should be supported by
kernels since  2.6.35 (I'm not sure what our minimum requirement is here for
Linux), but unfortunately the older Android NDK doesn't define PTRACE_GETREGSET.
 I've ifdef'ed it with #ifdef PTRACE_GETREGSET instead of #ifdef __aarch64__ -
wdyt?

https://breakpad.appspot.com/1354002/diff/20001/common/android/include/elf.h
File common/android/include/elf.h (right):

https://breakpad.appspot.com/1354002/diff/20001/common/android/include/elf.h#...
common/android/include/elf.h:60: #if !defined(ELFSIZE) && defined(ARCH_ELFSIZE)
On 2014/04/01 19:13:32, Mark Mentovai wrote:
> Did you take the changes to these files in common/android/include from the
> upstream files?

Removed this change - no longer necessary after the android header cleanup CL.

https://breakpad.appspot.com/1354002/diff/20001/common/android/ucontext_const...
File common/android/ucontext_constants.h (right):

https://breakpad.appspot.com/1354002/diff/20001/common/android/ucontext_const...
common/android/ucontext_constants.h:50: #define  MCONTEXT_GREGS_OFFSET     48
On 2014/04/01 19:13:32, Mark Mentovai wrote:
> Why aren’t these using offsetof?

Unfortunately that doesn't work since these are used by the assembly in
breakpad_getcontext.S, and offsetof only gets converted to a value at compile
time, not preprocess time.

https://breakpad.appspot.com/1354002/diff/20001/common/memory.h
File common/memory.h (right):

https://breakpad.appspot.com/1354002/diff/20001/common/memory.h#newcode113
common/memory.h:113: #if defined(__x86_64) || defined(__aarch64__)
On 2014/04/01 19:13:32, Mark Mentovai wrote:
> x86_64 is normally spelled in our codebase with the __ on both ends:
__x86_64__.

Done.

[Mark Mentovai]

LG otherwise

https://breakpad.appspot.com/1354002/diff/80001/client/linux/minidump_writer/...
File client/linux/minidump_writer/linux_ptrace_dumper.cc (right):

https://breakpad.appspot.com/1354002/diff/80001/client/linux/minidump_writer/...
client/linux/minidump_writer/linux_ptrace_dumper.cc:56: #if defined(__aarch64__)
This isn’t right now. Can this #include be unguarded?

https://breakpad.appspot.com/1354002/diff/80001/common/android/include/elf.h
File common/android/include/elf.h (right):

https://breakpad.appspot.com/1354002/diff/80001/common/android/include/elf.h#...
common/android/include/elf.h:116: #elif defined(__x86_64) ||
defined(__aarch64__)
__x86_64__ (and __i386__ two lines above)

[rmcilroy]

https://breakpad.appspot.com/1354002/diff/80001/client/linux/minidump_writer/...
File client/linux/minidump_writer/linux_ptrace_dumper.cc (right):

https://breakpad.appspot.com/1354002/diff/80001/client/linux/minidump_writer/...
client/linux/minidump_writer/linux_ptrace_dumper.cc:56: #if defined(__aarch64__)
On 2014/04/02 16:27:24, Mark Mentovai wrote:
> This isn’t right now. Can this #include be unguarded?

Ahh yes, thanks. Done.

https://breakpad.appspot.com/1354002/diff/80001/common/android/include/elf.h
File common/android/include/elf.h (right):

https://breakpad.appspot.com/1354002/diff/80001/common/android/include/elf.h#...
common/android/include/elf.h:116: #elif defined(__x86_64) ||
defined(__aarch64__)
On 2014/04/02 16:27:24, Mark Mentovai wrote:
> __x86_64__ (and __i386__ two lines above)

Done.

[Mark Mentovai]

LGTM

[rmcilroy]

Committed patchset #4 manually as r1301 (presubmit successful).