Do not clear %RFLAGS.DF on fast syscall entry.

Hardware already did it for us due to the mask loaded into the
MSR_SF_MASK msr register.

Reviewed by:	jhb
Sponsored by:	The FreeBSD Foundation
MFC after:	1 week
Differential revision:	https://reviews.freebsd.org/D13838
This commit is contained in:
Konstantin Belousov 2018-01-11 12:54:33 +00:00
parent 0f7c159f6b
commit 4975c202ac

View File

@ -410,7 +410,6 @@ IDTVEC(fast_syscall)
movq %r14,TF_R14(%rsp) /* C preserved */
movq %r15,TF_R15(%rsp) /* C preserved */
movl $TF_HASSEGS,TF_FLAGS(%rsp)
cld
FAKE_MCOUNT(TF_RIP(%rsp))
movq PCPU(CURTHREAD),%rdi
movq %rsp,TD_FRAME(%rdi)