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| author | Andy Lutomirski <luto@kernel.org> | 2017-11-02 00:59:09 -0700 |
|---|---|---|
| committer | Ingo Molnar <mingo@kernel.org> | 2017-11-02 11:04:43 +0100 |
| commit | bd7dc5a6afac719d8ce4092391eef2c7e83c2a75 (patch) | |
| tree | 2ee8471b8b2443be14f0badffe69befd7a76f8d2 /arch/x86/kernel/vm86_32.c | |
| parent | 929bacec21478a72c78e4f29f98fb799bd00105a (diff) | |
| download | linux-bd7dc5a6afac719d8ce4092391eef2c7e83c2a75.tar.bz2 | |
x86/entry/32: Pull the MSR_IA32_SYSENTER_CS update code out of native_load_sp0()
This causes the MSR_IA32_SYSENTER_CS write to move out of the
paravirt callback. This shouldn't affect Xen PV: Xen already ignores
MSR_IA32_SYSENTER_ESP writes. In any event, Xen doesn't support
vm86() in a useful way.
Note to any potential backporters: This patch won't break lguest, as
lguest didn't have any SYSENTER support at all.
Signed-off-by: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bpetkov@suse.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/75cf09fe03ae778532d0ca6c65aa58e66bc2f90c.1509609304.git.luto@kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'arch/x86/kernel/vm86_32.c')
| -rw-r--r-- | arch/x86/kernel/vm86_32.c | 6 |
1 files changed, 5 insertions, 1 deletions
diff --git a/arch/x86/kernel/vm86_32.c b/arch/x86/kernel/vm86_32.c index 7924a5356c8a..5bc1c3ab6287 100644 --- a/arch/x86/kernel/vm86_32.c +++ b/arch/x86/kernel/vm86_32.c @@ -54,6 +54,7 @@ #include <asm/irq.h> #include <asm/traps.h> #include <asm/vm86.h> +#include <asm/switch_to.h> /* * Known problems: @@ -149,6 +150,7 @@ void save_v86_state(struct kernel_vm86_regs *regs, int retval) tsk->thread.sp0 = vm86->saved_sp0; tsk->thread.sysenter_cs = __KERNEL_CS; load_sp0(tss, &tsk->thread); + refresh_sysenter_cs(&tsk->thread); vm86->saved_sp0 = 0; put_cpu(); @@ -368,8 +370,10 @@ static long do_sys_vm86(struct vm86plus_struct __user *user_vm86, bool plus) /* make room for real-mode segments */ tsk->thread.sp0 += 16; - if (static_cpu_has(X86_FEATURE_SEP)) + if (static_cpu_has(X86_FEATURE_SEP)) { tsk->thread.sysenter_cs = 0; + refresh_sysenter_cs(&tsk->thread); + } load_sp0(tss, &tsk->thread); put_cpu(); |