diff options
| author | Mark Kettenis <kettenis@cvs.openbsd.org> | 2023-07-08 07:18:40 +0000 |
|---|---|---|
| committer | Mark Kettenis <kettenis@cvs.openbsd.org> | 2023-07-08 07:18:40 +0000 |
| commit | b67df4c21695812cf0ad8dfd8117b877f86d5810 (patch) | |
| tree | 086d13098609acdf1259f4afe40f17966a0e6197 /sys | |
| parent | 5d6d05bfff01bc249963b00a33fdfb552c5c069d (diff) | |
Toggle IBT off during EFI runtime services calls.
While UEFI 2.10 has a way of indicating that runtime services use the
appropriate ENDBR64 instructions, firmware that's out int the wild doesn't
actually use that yet. Once the landscape changes we may want to
reconsider toggling IBT off.
ok guenther@, kn@
Diffstat (limited to 'sys')
| -rw-r--r-- | sys/arch/amd64/amd64/efi_machdep.c | 6 |
1 files changed, 5 insertions, 1 deletions
diff --git a/sys/arch/amd64/amd64/efi_machdep.c b/sys/arch/amd64/amd64/efi_machdep.c index 97be06b224b..7486ff106ac 100644 --- a/sys/arch/amd64/amd64/efi_machdep.c +++ b/sys/arch/amd64/amd64/efi_machdep.c @@ -1,4 +1,4 @@ -/* $OpenBSD: efi_machdep.c,v 1.6 2023/04/30 17:24:24 kettenis Exp $ */ +/* $OpenBSD: efi_machdep.c,v 1.7 2023/07/08 07:18:39 kettenis Exp $ */ /* * Copyright (c) 2022 Mark Kettenis <kettenis@openbsd.org> @@ -208,11 +208,15 @@ efi_enter(struct efi_softc *sc) fpu_kernel_enter(); curpcb->pcb_onfault = (void *)efi_fault; + if (curcpu()->ci_feature_sefflags_edx & SEFF0EDX_IBT) + lcr4(rcr4() & ~CR4_CET); } void efi_leave(struct efi_softc *sc) { + if (curcpu()->ci_feature_sefflags_edx & SEFF0EDX_IBT) + lcr4(rcr4() | CR4_CET); curpcb->pcb_onfault = NULL; fpu_kernel_exit(); |