[CRIU] [PATCHv2 0/9] x86/ptrace: Workaround Skylake bug

[Dmitry Safonov]

Changes for v2:
o Fix align gcc8.1 error *for real*
o Adress comments by Andrew, such as:
  - use in kdat test clone() instead of fork() (lighter)
  - use CLONE_UNTRACED to make kdat work under strace (tested)
  - Assume that criu doesn't set SIG_IGN to SIGCHLD and
    simplify error-checking

Origin description:

A nasty kernel(older v4.14) bug, resulted in incorrect C/R of fpu state.

Tested on Skylake Amazon VM with zdtm's fpu tests and fpu02..
Shlomi, will you be able by any chance to test this with your python
project and older kernel (ubuntu v4.13)?

Cc: Cyrill Gorcunov <gorcunov at gmail.com>
Cc: Andrei Vagin <avagin at virtuozzo.com>
Cc: Shlomi Matichin <shlomi at binaris.com>

Dmitry Safonov (9):
  x86/crtools: Add fork() err-path handle
  x86/kerndat: Add a check for ptrace() bug on Skylake
  compel/infect: Unite save_regs_t with save_regs() declaration
  compel: Add ctx flags to get_task_regs()
  compel/x86: Separate functions used to get fpu state
  compel/x86: Add workaround on ptrace() bug on Skylake
  compel: Cleanup INFECT_* definitions
  zdtm/x86: Add a mxcsr preserving fpu test
  compel: Explicitely align all containers of i387_fxsave_struct

 compel/arch/aarch64/src/lib/infect.c           |  3 +-
 compel/arch/arm/src/lib/infect.c               |  3 +-
 compel/arch/ppc64/src/lib/infect.c             |  3 +-
 compel/arch/s390/src/lib/infect.c              |  2 +-
 compel/arch/x86/src/lib/include/uapi/asm/fpu.h |  9 +--
 compel/arch/x86/src/lib/infect.c               | 57 ++++++++++++-----
 compel/include/infect-priv.h                   |  3 +-
 compel/include/uapi/infect.h                   | 21 ++++--
 compel/src/lib/infect.c                        |  5 +-
 criu/arch/x86/crtools.c                        | 84 +++++++++++++++++++++++-
 criu/arch/x86/include/asm/restorer.h           |  2 +
 criu/include/kerndat.h                         |  1 +
 criu/kerndat.c                                 | 18 ++++++
 criu/parasite-syscall.c                        |  2 +
 test/zdtm/static/Makefile                      |  1 +
 test/zdtm/static/fpu02.c                       | 88 ++++++++++++++++++++++++++
 16 files changed, 268 insertions(+), 34 deletions(-)
 create mode 100644 test/zdtm/static/fpu02.c

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2.13.6