Date: Thu, 29 Jul 2021 14:49:12 GMT From: Mark Johnston <markj@FreeBSD.org> To: src-committers@FreeBSD.org, dev-commits-src-all@FreeBSD.org, dev-commits-src-main@FreeBSD.org Subject: git: e15374508381 - main - amd64: Set MSR_KGSBASE to 0 during AP startup Message-ID: <202107291449.16TEnCMw055952@gitrepo.freebsd.org>
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The branch main has been updated by markj: URL: https://cgit.FreeBSD.org/src/commit/?id=e1537450838134daaf584d1f17e661673b2c4c76 commit e1537450838134daaf584d1f17e661673b2c4c76 Author: Mark Johnston <markj@FreeBSD.org> AuthorDate: 2021-07-29 14:14:05 +0000 Commit: Mark Johnston <markj@FreeBSD.org> CommitDate: 2021-07-29 14:14:05 +0000 amd64: Set MSR_KGSBASE to 0 during AP startup There is no reason to initialize it to anything else, and this matches initialization of the BSP. No functional change intended. Reviewed by: kib MFC after: 2 weeks Sponsored by: The FreeBSD Foundation Differential Revision: https://reviews.freebsd.org/D31336 --- sys/amd64/amd64/mp_machdep.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/sys/amd64/amd64/mp_machdep.c b/sys/amd64/amd64/mp_machdep.c index df0270c543e6..86a5d78c8a8e 100644 --- a/sys/amd64/amd64/mp_machdep.c +++ b/sys/amd64/amd64/mp_machdep.c @@ -262,8 +262,8 @@ init_secondary(void) lgdt(&ap_gdt); /* does magic intra-segment return */ wrmsr(MSR_FSBASE, 0); /* User value */ - wrmsr(MSR_GSBASE, (u_int64_t)pc); - wrmsr(MSR_KGSBASE, (u_int64_t)pc); /* XXX User value while we're in the kernel */ + wrmsr(MSR_GSBASE, (uint64_t)pc); + wrmsr(MSR_KGSBASE, 0); /* User value */ fix_cpuid(); lidt(&r_idt);
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