2 files changed, 10 insertions, 3 deletions

diff --git a/arch/i386/kernel/ioport.c b/arch/i386/kernel/ioport.c
index 8b25160393c1..f2b37654777f 100644
--- a/arch/i386/kernel/ioport.c
+++ b/arch/i386/kernel/ioport.c
@@ -132,6 +132,7 @@ asmlinkage long sys_iopl(unsigned long unused)
         volatile struct pt_regs * regs = (struct pt_regs *) &unused;
         unsigned int level = regs->ebx;
         unsigned int old = (regs->eflags >> 12) & 3;
+        struct thread_struct *t = &current->thread;
 
         if (level > 3)
                 return -EINVAL;
@@ -140,8 +141,8 @@ asmlinkage long sys_iopl(unsigned long unused)
                 if (!capable(CAP_SYS_RAWIO))
                         return -EPERM;
         }
-        regs->eflags = (regs->eflags &~ 0x3000UL) | (level << 12);
-        /* Make sure we return the long way (not sysenter) */
-        set_thread_flag(TIF_IRET);
+        t->iopl = level << 12;
+        regs->eflags = (regs->eflags & ~X86_EFLAGS_IOPL) | t->iopl;
+        set_iopl_mask(t->iopl);
         return 0;
 }
diff --git a/arch/i386/kernel/process.c b/arch/i386/kernel/process.c
index 660997800393..b45cbf93d439 100644
--- a/arch/i386/kernel/process.c
+++ b/arch/i386/kernel/process.c
@@ -712,6 +712,12 @@ struct task_struct fastcall * __switch_to(struct task_struct *prev_p, struct tas
                 loadsegment(gs, next->gs);
 
         /*
+         * Restore IOPL if needed.
+         */
+        if (unlikely(prev->iopl != next->iopl))
+                set_iopl_mask(next->iopl);
+
+        /*
          * Now maybe reload the debug registers
          */
         if (unlikely(next->debugreg[7])) {