x86: refactor ioport unification

Refactor ioport unification to pull out common code.

Cc: mboton@gmail.com
Cc: Kevin Winchester <kjwinchester@gmail.com>
Cc: Zach Brown <zach.brown@oracle.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Signed-off-by: Chris Wright <chrisw@sous-sol.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

1 files changed, 21 insertions, 19 deletions

diff --git a/arch/x86/kernel/ioport.c b/arch/x86/kernel/ioport.c
index be72d809bce7..50e5e4a31c85 100644
--- a/arch/x86/kernel/ioport.c
+++ b/arch/x86/kernel/ioport.c
@@ -113,13 +113,9 @@ asmlinkage long sys_ioperm(unsigned long from, unsigned long num, int turn_on)
  * on system-call entry - see also fork() and the signal handling
  * code.
  */
-#ifdef CONFIG_X86_32
-asmlinkage long sys_iopl(unsigned long regsp)
+static int do_iopl(unsigned int level, struct pt_regs *regs)
 {
-        struct pt_regs *regs = (struct pt_regs *)&regsp;
-        unsigned int level = regs->bx;
         unsigned int old = (regs->flags >> 12) & 3;
-        struct thread_struct *t = &current->thread;
 
         if (level > 3)
                 return -EINVAL;
@@ -128,25 +124,31 @@ asmlinkage long sys_iopl(unsigned long regsp)
                 if (!capable(CAP_SYS_RAWIO))
                         return -EPERM;
         }
-        t->iopl = level << 12;
         regs->flags = (regs->flags & ~X86_EFLAGS_IOPL) | (level << 12);
-        set_iopl_mask(t->iopl);
+
         return 0;
 }
-#else
-asmlinkage long sys_iopl(unsigned int level, struct pt_regs *regs)
+
+#ifdef CONFIG_X86_32
+asmlinkage long sys_iopl(unsigned long regsp)
 {
-        unsigned int old = (regs->flags >> 12) & 3;
+        struct pt_regs *regs = (struct pt_regs *)&regsp;
+        unsigned int level = regs->bx;
+        struct thread_struct *t = &current->thread;
+        int rc;
 
-        if (level > 3)
-                return -EINVAL;
-        /* Trying to gain more privileges? */
-        if (level > old) {
-                if (!capable(CAP_SYS_RAWIO))
-                        return -EPERM;
-        }
-        regs->flags = (regs->flags & ~X86_EFLAGS_IOPL) | (level << 12);
+        rc = do_iopl(level, regs);
+        if (rc < 0)
+                goto out;
 
-        return 0;
+        t->iopl = level << 12;
+        set_iopl_mask(t->iopl);
+out:
+        return rc;
+}
+#else
+asmlinkage long sys_iopl(unsigned int level, struct pt_regs *regs)
+{
+        return do_iopl(level, regs);
 }
 #endif