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| author | Alex Shi <alex.shi@linaro.org> | 2016-05-05 13:36:03 +0800 |
|---|---|---|
| committer | Alex Shi <alex.shi@linaro.org> | 2016-05-05 13:36:03 +0800 |
| commit | e91b1cc90283c1b9b75670b027a18afbd20fe070 (patch) | |
| tree | 81c395406a3774775a183d544aee9c5ced1c31d6 /arch/x86/kernel/process_64.c | |
| parent | d83731cf53fd3af7173cab5e3f573d06ebc852be (diff) | |
| parent | 0b3df30dcadcddc56aed56c3c2d2de2ca963e81d (diff) | |
Merge branch 'linux-linaro-lsk-v4.1' into linux-linaro-lsk-v4.1-rtlsk-v4.1-16.06-rtlsk-v4.1-16.05-rt
Diffstat (limited to 'arch/x86/kernel/process_64.c')
| -rw-r--r-- | arch/x86/kernel/process_64.c | 12 |
1 files changed, 12 insertions, 0 deletions
diff --git a/arch/x86/kernel/process_64.c b/arch/x86/kernel/process_64.c index 58e02d938218..f7724a1d7de1 100644 --- a/arch/x86/kernel/process_64.c +++ b/arch/x86/kernel/process_64.c @@ -49,6 +49,7 @@ #include <asm/syscalls.h> #include <asm/debugreg.h> #include <asm/switch_to.h> +#include <asm/xen/hypervisor.h> asmlinkage extern void ret_from_fork(void); @@ -419,6 +420,17 @@ __switch_to(struct task_struct *prev_p, struct task_struct *next_p) task_thread_info(prev_p)->flags & _TIF_WORK_CTXSW_PREV)) __switch_to_xtra(prev_p, next_p, tss); +#ifdef CONFIG_XEN + /* + * On Xen PV, IOPL bits in pt_regs->flags have no effect, and + * current_pt_regs()->flags may not match the current task's + * intended IOPL. We need to switch it manually. + */ + if (unlikely(xen_pv_domain() && + prev->iopl != next->iopl)) + xen_set_iopl_mask(next->iopl); +#endif + if (static_cpu_has_bug(X86_BUG_SYSRET_SS_ATTRS)) { /* * AMD CPUs have a misfeature: SYSRET sets the SS selector but |