The branch main has been updated by kib:
URL:
https://cgit.FreeBSD.org/src/commit/?id=e8b2980e4a126407e15d33ee8d987385c8321261
commit e8b2980e4a126407e15d33ee8d987385c8321261
Author: Konstantin Belousov <k...@freebsd.org>
AuthorDate: 2022-08-18 04:07:29 +0000
Commit: Konstantin Belousov <k...@freebsd.org>
CommitDate: 2022-08-24 19:12:05 +0000
i386 doreti: stop saving/restoring %ecx around calls into C
There is no reason to do this. Instead just calculate it later.
Reviewed by: jhb
Tested by: pho
Sponsored by: The FreeBSD Foundation
MFC after: 1 week
Differential revision: https://reviews.freebsd.org/D36302
---
sys/i386/i386/exception.s | 17 ++++++++---------
1 file changed, 8 insertions(+), 9 deletions(-)
diff --git a/sys/i386/i386/exception.s b/sys/i386/i386/exception.s
index 5eef9c1d512c..8279a4602ebf 100644
--- a/sys/i386/i386/exception.s
+++ b/sys/i386/i386/exception.s
@@ -518,22 +518,21 @@ doreti_exit:
je doreti_iret_nmi
cmpl $T_TRCTRAP, TF_TRAPNO(%esp)
je doreti_iret_nmi
- movl $TF_SZ, %ecx
testl $PSL_VM,TF_EFLAGS(%esp)
- jz 1f /* PCB_VM86CALL is not set */
- addl $VM86_STACK_SPACE, %ecx
- jmp 2f
-1: testl $SEL_RPL_MASK, TF_CS(%esp)
+ jnz 1f /* PCB_VM86CALL is not set */
+ testl $SEL_RPL_MASK, TF_CS(%esp)
jz doreti_popl_fs
-2: movl $handle_ibrs_exit,%eax
- pushl %ecx /* preserve enough call-used regs */
+1: movl $handle_ibrs_exit,%eax
call *%eax
movl mds_handler,%eax
call *%eax
- popl %ecx
movl %esp, %esi
movl PCPU(TRAMPSTK), %edx
- subl %ecx, %edx
+ movl $TF_SZ, %ecx
+ testl $PSL_VM,TF_EFLAGS(%esp)
+ jz 2f /* PCB_VM86CALL is not set */
+ addl $VM86_STACK_SPACE, %ecx
+2: subl $TF_SZ, %edx
movl %edx, %edi
rep; movsb
movl %edx, %esp
