On 7/20/26 17:51, Konstantin Belousov wrote:
The branch main has been updated by kib:
URL:
https://cgit.FreeBSD.org/src/commit/?id=6e93f5e4d6932c423b89dff8fc08d86f8bdeb7b9
commit 6e93f5e4d6932c423b89dff8fc08d86f8bdeb7b9
Author: Konstantin Belousov <[email protected]>
AuthorDate: 2026-02-13 11:24:40 +0000
Commit: Konstantin Belousov <[email protected]>
CommitDate: 2026-07-20 21:51:02 +0000
amd64: FRED support
FRED support as defined starting from the SDM rev. 90, requires a new
'events' entry point to receive user and kernel mode exceptions and
interrupts notifications from the hardware. A minimal asm trampoline is
enough, rest can be implemented in C due to the clean FRED organization
of the event reporting.
The syscall entry is handled by a microptimized assembly path, directly
calling into the amd64_syscall() handler, instead of the generic events
entry point.
Tested by: emaste
Sponsored by: The FreeBSD Foundation
MFC after: 1 week
Differential revision: https://reviews.freebsd.org/D55829
This appears to have broken the cross-build jobs on GitHub for the past week
which build with clang 15 and clang 18. Are those versions too old to support
the instructions used here?
Sample output:
--------------------------------------------------------------
stage 3.1: building everything
--------------------------------------------------------------
/home/runner/work/freebsd-src/freebsd-src/sys/amd64/amd64/exception.S:1455:2:
error: invalid instruction mnemonic 'eretu'
eretu
^~~~~
/home/runner/work/freebsd-src/freebsd-src/sys/amd64/amd64/exception.S:1521:2:
error: invalid instruction mnemonic 'lkgs'
lkgs %ax
^~~~
/home/runner/work/freebsd-src/freebsd-src/sys/amd64/amd64/exception.S:1542:2:
error: invalid instruction mnemonic 'eretu'
eretu
^~~~~
/home/runner/work/freebsd-src/freebsd-src/sys/amd64/amd64/exception.S:1662:2:
error: invalid instruction mnemonic 'erets'
erets
^~~~~
/home/runner/work/freebsd-src/freebsd-src/sys/amd64/amd64/exception.S:1682:2:
error: invalid instruction mnemonic 'erets'
erets
^~~~~
--- exception.o ---
*** [exception.o] Error code 1
(Or maybe clang needs some -m<foo> or .set <foo> to enable use of these
instructions?)
--
John Baldwin
