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| author | Linus Torvalds <torvalds@linux-foundation.org> | 2016-03-24 09:47:32 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2016-03-24 09:47:32 -0700 |
| commit | d88f48e12821ab4b2244124d50ac094568f48db5 (patch) | |
| tree | 4eb16b46898190aac33ed6125a9a0e734d5be10e /arch/x86/kernel/process_64.c | |
| parent | be53f58fa0fcd97c62a84f2eb98cff528f8b2443 (diff) | |
| parent | 9da77666d6975219281fd400eb9608a047337414 (diff) | |
| download | linux-d88f48e12821ab4b2244124d50ac094568f48db5.tar.bz2 | |
Merge branch 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 fixes from Ingo Molnar:
"Misc fixes:
- fix hotplug bugs
- fix irq live lock
- fix various topology handling bugs
- fix APIC ACK ordering
- fix PV iopl handling
- fix speling
- fix/tweak memcpy_mcsafe() return value
- fix fbcon bug
- remove stray prototypes"
* 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/msr: Remove unused native_read_tscp()
x86/apic: Remove declaration of unused hw_nmi_is_cpu_stuck
x86/oprofile/nmi: Add missing hotplug FROZEN handling
x86/hpet: Use proper mask to modify hotplug action
x86/apic/uv: Fix the hotplug notifier
x86/apb/timer: Use proper mask to modify hotplug action
x86/topology: Use total_cpus not nr_cpu_ids for logical packages
x86/topology: Fix Intel HT disable
x86/topology: Fix logical package mapping
x86/irq: Cure live lock in fixup_irqs()
x86/tsc: Prevent NULL pointer deref in calibrate_delay_is_known()
x86/apic: Fix suspicious RCU usage in smp_trace_call_function_interrupt()
x86/iopl: Fix iopl capability check on Xen PV
x86/iopl/64: Properly context-switch IOPL on Xen PV
selftests/x86: Add an iopl test
x86/mm, x86/mce: Fix return type/value for memcpy_mcsafe()
x86/video: Don't assume all FB devices are PCI devices
arch/x86/irq: Purge useless handler declarations from hw_irq.h
x86: Fix misspellings in comments
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 dfa2781610e8..6cbab31ac23a 100644 --- a/arch/x86/kernel/process_64.c +++ b/arch/x86/kernel/process_64.c @@ -48,6 +48,7 @@ #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); @@ -413,6 +414,17 @@ __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(static_cpu_has(X86_FEATURE_XENPV) && + 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 |