From a1bf250a6f31afb8caac166ae50dc7b89c38084c Mon Sep 17 00:00:00 2001
From: Chris Wright <chrisw@sous-sol.org>
Date: Wed, 30 Jan 2008 13:33:10 +0100
Subject: [PATCH] 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>
---
 arch/x86/kernel/ioport.c | 46 +++++++++++++++++++++-------------------
 1 file changed, 24 insertions(+), 22 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
@@ -113,40 +113,42 @@ 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.
  */
+static int do_iopl(unsigned int level, struct pt_regs *regs)
+{
+	unsigned int old = (regs->flags >> 12) & 3;
+
+	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);
+
+	return 0;
+}
+
 #ifdef CONFIG_X86_32
 asmlinkage long sys_iopl(unsigned long regsp)
 {
 	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;
+	int rc;
+
+	rc = do_iopl(level, regs);
+	if (rc < 0)
+		goto out;
 
-	if (level > 3)
-		return -EINVAL;
-	/* Trying to gain more privileges? */
-	if (level > old) {
-		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;
+out:
+	return rc;
 }
 #else
 asmlinkage long sys_iopl(unsigned int level, struct pt_regs *regs)
 {
-	unsigned int old = (regs->flags >> 12) & 3;
-
-	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);
-
-	return 0;
+	return do_iopl(level, regs);
 }
 #endif