diff options
| author | Philip Guenther <guenther@cvs.openbsd.org> | 2018-03-13 05:10:41 +0000 |
|---|---|---|
| committer | Philip Guenther <guenther@cvs.openbsd.org> | 2018-03-13 05:10:41 +0000 |
| commit | eff3ec5f17b83e30220790cf58d96f9cdc664246 (patch) | |
| tree | ffd008ef5778cbc8c7071358140724e6db645bc8 /sys/arch/amd64 | |
| parent | aa6e0fdffa87fe91cde00764cf5a7adc919c10b8 (diff) | |
We don't save+restore FS.base and GS.base on every context switch but
rather reset GS.base and restore FS.base to what was set via __tcb_set(),
so we can't really support the wr{fs,gs}base instructions by userspace.
Enabling CR4_FSGSBASE is therefore incorrect so stop doing so.
ok jsg@ krw@
Diffstat (limited to 'sys/arch/amd64')
| -rw-r--r-- | sys/arch/amd64/amd64/cpu.c | 4 |
1 files changed, 1 insertions, 3 deletions
diff --git a/sys/arch/amd64/amd64/cpu.c b/sys/arch/amd64/amd64/cpu.c index 7e14b3709de..00f8b8bd79e 100644 --- a/sys/arch/amd64/amd64/cpu.c +++ b/sys/arch/amd64/amd64/cpu.c @@ -1,4 +1,4 @@ -/* $OpenBSD: cpu.c,v 1.112 2018/02/21 19:24:15 guenther Exp $ */ +/* $OpenBSD: cpu.c,v 1.113 2018/03/13 05:10:40 guenther Exp $ */ /* $NetBSD: cpu.c,v 1.1 2003/04/26 18:39:26 fvdl Exp $ */ /*- @@ -520,8 +520,6 @@ cpu_init(struct cpu_info *ci) cr4 |= CR4_SMEP; if (ci->ci_feature_sefflags_ebx & SEFF0EBX_SMAP) cr4 |= CR4_SMAP; - if (ci->ci_feature_sefflags_ebx & SEFF0EBX_FSGSBASE) - cr4 |= CR4_FSGSBASE; if (ci->ci_feature_sefflags_ecx & SEFF0ECX_UMIP) cr4 |= CR4_UMIP; if (cpu_ecxfeature & CPUIDECX_XSAVE) |