This RFC series adds s390 support for unwinding of signal frames in user
space using SFrame V3's indication of signal frames.


Prerequirements:

This series applies on top of the latest unwind user sframe s390 series
"[PATCH v4 00/12] s390: SFrame user space unwinding":
https://lore.kernel.org/all/20260127151926.2805123-1-jremus@linux.ibm.com/

on top of the latest unwind user sframe series
"[PATCH v13 00/18] unwind_deferred: Implement sframe handling":
https://lore.kernel.org/all/20260127150554.2760964-1-jremus@linux.ibm.com/

Like above series it depends on the upcoming binutils 2.46 release to
be used to build executables and libraries (e.g. vDSO) with SFrame V3
on s390 (using the assembler option --gsframe-3).


Overview:

Patches 1 and 2 enables the common unwind user (sframe) frameworks to
support signal frames:

- Patch 1 enables unwind user to resort to an architecture-specific
  signal frame unwinder, if a frame is a signal frame.

- Patch 2 adds support to unwind user sframe to provide the signal
  frame indication represented in SFrame V3.

Patch 3 annotates the s390 vDSO functions __kernel_[rt_]sigreturn()
as signal frames.

Patch 4 moves the s390 struct [rt_]sigframe to asm/sigframe.h so that
it can be used in unwind user.

Patch 5 enables signal frame unwinding in user space on s390.

Regards,
Jens


Jens Remus (5):
  unwind_user: Enable arch-specific signal frame unwinders
  unwind_user/sframe: Add support for signal frame indication
  s390/vdso: Annotate __kernel_[rt_]sigreturn as signal frames
  s390/signal: Move struct [rt_]sigframe to asm/sigframe.h
  s390/unwind_user: Enable signal frame unwinding of user space

 arch/s390/include/asm/dwarf.h             |  3 +
 arch/s390/include/asm/sigframe.h          | 78 +++++++++++++++++++++++
 arch/s390/include/asm/unwind_user.h       | 57 +++++++++++++++++
 arch/s390/kernel/signal.c                 | 71 +--------------------
 arch/s390/kernel/vdso/vdso_user_wrapper.S | 15 ++++-
 arch/x86/include/asm/unwind_user.h        |  6 +-
 include/linux/unwind_user.h               |  9 +++
 include/linux/unwind_user_types.h         |  1 +
 kernel/unwind/sframe.c                    |  8 ++-
 kernel/unwind/sframe.h                    |  1 +
 kernel/unwind/user.c                      |  4 ++
 11 files changed, 178 insertions(+), 75 deletions(-)
 create mode 100644 arch/s390/include/asm/sigframe.h

-- 
2.51.0