On Tue, 4 May 2021 at 23:13, Eric W. Biederman [off-list ref] wrote:

This set of changes sorts out the ABI issues with SIGTRAP TRAP_PERF, and
hopefully will can get merged before any userspace code starts using the
new ABI.

The big ideas are:
- Placing the asserts first to prevent unexpected ABI changes
- si_trapno becomming ordinary fault subfield.
- struct signalfd_siginfo is almost full

This set of changes starts out with Marco's static_assert changes and
additional one of my own that enforces the fact that the alignment of
siginfo_t is also part of the ABI.  Together these build time
checks verify there are no unexpected ABI changes in the changes
that follow.

The field si_trapno is changed to become an ordinary extension of the
_sigfault member of siginfo.

The code is refactored a bit and then si_perf_type is added along side
si_perf_data in the _perf subfield of _sigfault of siginfo_t.

Finally the signalfd_siginfo fields are removed as they appear to be
filling up the structure without userspace actually being able to use
them.

v2: https://lkml.kernel.org/r/m14kfjh8et.fsf_-_@fess.ebiederm.org
v1: https://lkml.kernel.org/r/m1zgxfs7zq.fsf_-_@fess.ebiederm.org

Eric W. Biederman (9):
      signal: Verify the alignment and size of siginfo_t
      siginfo: Move si_trapno inside the union inside _si_fault
      signal: Implement SIL_FAULT_TRAPNO
      signal: Use dedicated helpers to send signals with si_trapno set
      signal: Remove __ARCH_SI_TRAPNO
      signal: Rename SIL_PERF_EVENT SIL_FAULT_PERF_EVENT for consistency
      signal: Factor force_sig_perf out of perf_sigtrap
      signal: Deliver all of the siginfo perf data in _perf
      signalfd: Remove SIL_FAULT_PERF_EVENT fields from signalfd_siginfo

Marco Elver (3):
      sparc64: Add compile-time asserts for siginfo_t offsets
      arm: Add compile-time asserts for siginfo_t offsets
      arm64: Add compile-time asserts for siginfo_t offsets

I can't seem to see the rest of them in my inbox. LKML also is missing
them: https://lore.kernel.org/linux-api/m1tuni8ano.fsf_-_@fess.ebiederm.org/ (local)

Something must have swallowed them. Could you resend?
I'll then test in the morning.

Thanks,
-- Marco