Hi Eric,
On Tue, May 4, 2021 at 11:14 PM 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.
Thanks for your series, which is now in next-20210506.
arch/alpha/include/uapi/asm/siginfo.h | 2 -
arch/alpha/kernel/osf_sys.c | 2 +-
arch/alpha/kernel/signal.c | 4 +-
arch/alpha/kernel/traps.c | 24 ++---
arch/alpha/mm/fault.c | 4 +-
arch/arm/kernel/signal.c | 39 +++++++
arch/arm64/kernel/signal.c | 39 +++++++
arch/arm64/kernel/signal32.c | 39 +++++++
arch/mips/include/uapi/asm/siginfo.h | 2 -
arch/sparc/include/uapi/asm/siginfo.h | 3 -
arch/sparc/kernel/process_64.c | 2 +-
arch/sparc/kernel/signal32.c | 37 +++++++
arch/sparc/kernel/signal_64.c | 36 +++++++
arch/sparc/kernel/sys_sparc_32.c | 2 +-
arch/sparc/kernel/sys_sparc_64.c | 2 +-
arch/sparc/kernel/traps_32.c | 22 ++--
arch/sparc/kernel/traps_64.c | 44 ++++----
arch/sparc/kernel/unaligned_32.c | 2 +-
arch/sparc/mm/fault_32.c | 2 +-
arch/sparc/mm/fault_64.c | 2 +-
arch/x86/kernel/signal_compat.c | 15 ++-
No changes needed for other architectures?
All m68k configs are broken with
arch/m68k/kernel/signal.c:626:35: error: 'siginfo_t' {aka 'struct
siginfo'} has no member named 'si_perf'; did you mean 'si_errno'?
See e.g. http://kisskb.ellerman.id.au/kisskb/buildresult/14537820/
There are still a few more references left to si_perf:
$ git grep -n -w si_perf
Next/merge.log:2902:Merging userns/for-next (4cf4e48fff05 signal: sort
out si_trapno and si_perf)
arch/m68k/kernel/signal.c:626: BUILD_BUG_ON(offsetof(siginfo_t,
si_perf) != 0x10);
include/uapi/linux/perf_event.h:467: * siginfo_t::si_perf, e.g. to
permit user to identify the event.
tools/testing/selftests/perf_events/sigtrap_threads.c:46:/* Unique
value to check si_perf is correctly set from
perf_event_attr::sig_data. */
Thanks!
Gr{oetje,eeting}s,
Geert
--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org
In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
-- Linus Torvalds