[RFC,00/15] rseq uapi and selftest updates

Message

Mathieu Desnoyers Jan. 24, 2022, 5:12 p.m. UTC

Update the rseq selftests to adapt to the userspace ABI chosen by glibc
(will be released in February 2022). Provide a fallback implementation
to work with older glibc as well.

Remove broken 32-bit little/big endian accessor fields in rseq uapi.

Integrate various fixes gathered from librseq, including work-around for
known gcc and clang compiler bugs with asm goto.

The uplift to glibc's userspace ABI means we can now use %fs/%gs segment
selectors directly in the inline assembler for accesses to the rseq
thread area on x86.

Feedback is welcome,

Thanks,

Mathieu

Mathieu Desnoyers (15):
  selftests/rseq: introduce own copy of rseq uapi header
  rseq: Remove broken uapi field layout on 32-bit little endian
  selftests/rseq: Remove useless assignment to cpu variable
  selftests/rseq: Remove volatile from __rseq_abi
  selftests/rseq: Introduce rseq_get_abi() helper
  selftests/rseq: Introduce thread pointer getters
  selftests/rseq: Uplift rseq selftests for compatibility with
    glibc-2.35
  selftests/rseq: Fix ppc32: wrong rseq_cs 32-bit field pointer on big
    endian
  selftests/rseq: Fix ppc32 missing instruction selection "u" and "x"
    for load/store
  selftests/rseq: Fix ppc32 offsets by using long rather than off_t
  selftests/rseq: Fix warnings about #if checks of undefined tokens
  selftests/rseq: Remove arm/mips asm goto compiler work-around
  selftests/rseq: Fix: work-around asm goto compiler bugs
  selftests/rseq: x86-64: use %fs segment selector for accessing rseq
    thread area
  selftests/rseq: x86-32: use %gs segment selector for accessing rseq
    thread area

 include/uapi/linux/rseq.h                     |  17 +-
 tools/testing/selftests/rseq/Makefile         |   2 +-
 .../selftests/rseq/basic_percpu_ops_test.c    |   2 +-
 tools/testing/selftests/rseq/compiler.h       |  30 +++
 tools/testing/selftests/rseq/param_test.c     |   8 +-
 tools/testing/selftests/rseq/rseq-abi.h       | 151 +++++++++++++
 tools/testing/selftests/rseq/rseq-arm.h       | 110 +++++-----
 tools/testing/selftests/rseq/rseq-arm64.h     |  79 +++++--
 .../rseq/rseq-generic-thread-pointer.h        |  25 +++
 tools/testing/selftests/rseq/rseq-mips.h      |  71 ++-----
 .../selftests/rseq/rseq-ppc-thread-pointer.h  |  30 +++
 tools/testing/selftests/rseq/rseq-ppc.h       | 128 +++++++----
 tools/testing/selftests/rseq/rseq-s390.h      |  55 +++--
 tools/testing/selftests/rseq/rseq-skip.h      |   2 +-
 .../selftests/rseq/rseq-thread-pointer.h      |  19 ++
 .../selftests/rseq/rseq-x86-thread-pointer.h  |  40 ++++
 tools/testing/selftests/rseq/rseq-x86.h       | 200 ++++++++++++------
 tools/testing/selftests/rseq/rseq.c           | 163 +++++++-------
 tools/testing/selftests/rseq/rseq.h           |  29 ++-
 19 files changed, 793 insertions(+), 368 deletions(-)
 create mode 100644 tools/testing/selftests/rseq/compiler.h
 create mode 100644 tools/testing/selftests/rseq/rseq-abi.h
 create mode 100644 tools/testing/selftests/rseq/rseq-generic-thread-pointer.h
 create mode 100644 tools/testing/selftests/rseq/rseq-ppc-thread-pointer.h
 create mode 100644 tools/testing/selftests/rseq/rseq-thread-pointer.h
 create mode 100644 tools/testing/selftests/rseq/rseq-x86-thread-pointer.h

Comments

Peter Zijlstra Jan. 27, 2022, 3:46 p.m. UTC | #1

On Mon, Jan 24, 2022 at 12:12:38PM -0500, Mathieu Desnoyers wrote:
> Mathieu Desnoyers (15):
>   selftests/rseq: introduce own copy of rseq uapi header
>   rseq: Remove broken uapi field layout on 32-bit little endian
>   selftests/rseq: Remove useless assignment to cpu variable
>   selftests/rseq: Remove volatile from __rseq_abi
>   selftests/rseq: Introduce rseq_get_abi() helper
>   selftests/rseq: Introduce thread pointer getters
>   selftests/rseq: Uplift rseq selftests for compatibility with
>     glibc-2.35
>   selftests/rseq: Fix ppc32: wrong rseq_cs 32-bit field pointer on big
>     endian
>   selftests/rseq: Fix ppc32 missing instruction selection "u" and "x"
>     for load/store
>   selftests/rseq: Fix ppc32 offsets by using long rather than off_t
>   selftests/rseq: Fix warnings about #if checks of undefined tokens
>   selftests/rseq: Remove arm/mips asm goto compiler work-around
>   selftests/rseq: Fix: work-around asm goto compiler bugs
>   selftests/rseq: x86-64: use %fs segment selector for accessing rseq
>     thread area
>   selftests/rseq: x86-32: use %gs segment selector for accessing rseq
>     thread area

Thanks, I'll go stick then in sched/core.