[PATCH v2 0/4] arm64: Fix single-step handling

[Will Deacon]

Hi all,

This is version two of the patches I previously posted here:

  v1: https://lore.kernel.org/linux-arm-kernel/20200603151033.11512-1-will@kernel.org/

Thanks to Keno for a bunch of helpful feedback on that, which has led to
the following major changes for v2:

  - Use pseudo-step traps for both entering a signal handler and exiting a
    system call.

  - Document our weird x7 behaviour with PTRACE_SYSCALL.

It has to be said that I'm a bit nervous about these changes. I played
around with GDB and things seemed ok, but I would really appreciate it
if Luis could run the GDB testsuite with these changes applied.

Cheers,

Will

Cc: <kernel-team at android.com>
Cc: Mark Rutland <mark.rutland at arm.com>
Cc: Luis Machado <luis.machado at linaro.org>
Cc: Keno Fischer <keno at juliacomputing.com>

--->8


Will Deacon (4):
  arm64: ptrace: Add a comment describing our syscall entry/exit trap
    ABI
  arm64: ptrace: Consistently use pseudo-singlestep exceptions
  arm64: Override SPSR.SS when single-stepping is enabled
  arm64: Use test_tsk_thread_flag() for checking TIF_SINGLESTEP

 arch/arm64/include/asm/debug-monitors.h |  2 ++
 arch/arm64/include/asm/thread_info.h    |  1 +
 arch/arm64/kernel/debug-monitors.c      | 24 +++++++++----
 arch/arm64/kernel/ptrace.c              | 45 +++++++++++++++++++------
 arch/arm64/kernel/signal.c              | 11 ++----
 arch/arm64/kernel/syscall.c             |  2 +-
 6 files changed, 59 insertions(+), 26 deletions(-)

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2.27.0.212.ge8ba1cc988-goog