x86: ioport_{32|64}.c unification

ioport_{32|64}.c unification.

This patch unifies the code from the ioport_32.c and ioport_64.c files.

Tested and working fine with i386 and x86_64 kernels.
Signed-off-by: NMiguel Botón <mboton@gmail.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>

arch/x86/kernel/Makefile

@@ -10,7 +10,7 @@ CFLAGS_vsyscall_64.o := $(PROFILING) -g0
 
 obj-y			:= process_$(BITS).o signal_$(BITS).o entry_$(BITS).o
 obj-y			+= traps_$(BITS).o irq_$(BITS).o
-obj-y			+= time_$(BITS).o ioport_$(BITS).o ldt.o
+obj-y			+= time_$(BITS).o ioport.o ldt.o
 obj-y			+= setup_$(BITS).o i8259_$(BITS).o
 obj-$(CONFIG_X86_32)	+= sys_i386_32.o i386_ksyms_32.o
 obj-$(CONFIG_X86_64)	+= sys_x86_64.o x8664_ksyms_64.o

arch/x86/kernel/ioport_32.c → arch/x86/kernel/ioport.c

 /*
  * This contains the io-permission bitmap code - written by obz, with changes
- * by Linus.
+ * by Linus. 32/64 bits code unification by Miguel Botón.
  */
 
 #include <linux/sched.h>
@@ -36,7 +36,7 @@ asmlinkage long sys_ioperm(unsigned long from, unsigned long num, int turn_on)
 {
 	struct thread_struct * t = &current->thread;
 	struct tss_struct * tss;
-	unsigned long i, max_long;
+	unsigned int i, max_long, bytes, bytes_updated;
 
 	if ((from + num <= from) || (from + num > IO_BITMAP_BITS))
 		return -EINVAL;
@@ -79,8 +79,12 @@ asmlinkage long sys_ioperm(unsigned long from, unsigned long num, int turn_on)
 		if (t->io_bitmap_ptr[i] != ~0UL)
 			max_long = i;
 
-	t->io_bitmap_max = (max_long + 1) * sizeof(unsigned long);
+	bytes = (max_long + 1) * sizeof(unsigned long);
+	bytes_updated = max(bytes, t->io_bitmap_max);
 
+	t->io_bitmap_max = bytes;
+
+#ifdef CONFIG_X86_32
 	/*
 	 * Sets the lazy trigger so that the next I/O operation will
 	 * reload the correct bitmap.
@@ -89,6 +93,10 @@ asmlinkage long sys_ioperm(unsigned long from, unsigned long num, int turn_on)
 	 */
 	tss->x86_tss.io_bitmap_base = INVALID_IO_BITMAP_OFFSET_LAZY;
 	tss->io_bitmap_owner = NULL;
+#else
+	/* Update the TSS: */
+	memcpy(tss->io_bitmap, t->io_bitmap_ptr, bytes_updated);
+#endif
 
 	put_cpu();
 
@@ -105,13 +113,12 @@ 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)
 {
 	volatile 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;
@@ -120,10 +127,24 @@ asmlinkage long sys_iopl(unsigned long regsp)
 		if (!capable(CAP_SYS_RAWIO))
 			return -EPERM;
 	}
+	regs->flags = (regs->flags & ~X86_EFLAGS_IOPL) | (level << 12);
+
+	return 0;
+}
+#else
+asmlinkage long sys_iopl(unsigned int level, struct pt_regs *regs)
+{
+	unsigned int old = (regs->flags >> 12) & 3;
 
-	t->iopl = level << 12;
-	regs->flags = (regs->flags & ~X86_EFLAGS_IOPL) | t->iopl;
-	set_iopl_mask(t->iopl);
+	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;
 }
+#endif

arch/x86/kernel/ioport_64.c

-/*
- * This contains the io-permission bitmap code - written by obz, with changes
- * by Linus.
- */
-
-#include <linux/sched.h>
-#include <linux/kernel.h>
-#include <linux/capability.h>
-#include <linux/errno.h>
-#include <linux/types.h>
-#include <linux/ioport.h>
-#include <linux/smp.h>
-#include <linux/stddef.h>
-#include <linux/slab.h>
-#include <linux/thread_info.h>
-#include <linux/syscalls.h>
-
-/* Set EXTENT bits starting at BASE in BITMAP to value TURN_ON. */
-static void set_bitmap(unsigned long *bitmap, unsigned int base, unsigned int extent, int new_value)
-{
-	int i;
-		if (new_value)
-		for (i = base; i < base + extent; i++) 
-			__set_bit(i, bitmap); 
-		else
-		for (i = base; i < base + extent; i++) 
-			clear_bit(i, bitmap); 
-}
-
-/*
- * this changes the io permissions bitmap in the current task.
- */
-asmlinkage long sys_ioperm(unsigned long from, unsigned long num, int turn_on)
-{
-	unsigned int i, max_long, bytes, bytes_updated;
-	struct thread_struct * t = &current->thread;
-	struct tss_struct * tss;
-	unsigned long *bitmap;
-
-	if ((from + num <= from) || (from + num > IO_BITMAP_BITS))
-		return -EINVAL;
-	if (turn_on && !capable(CAP_SYS_RAWIO))
-		return -EPERM;
-
-	/*
-	 * If it's the first ioperm() call in this thread's lifetime, set the
-	 * IO bitmap up. ioperm() is much less timing critical than clone(),
-	 * this is why we delay this operation until now:
-	 */
-	if (!t->io_bitmap_ptr) {
-		bitmap = kmalloc(IO_BITMAP_BYTES, GFP_KERNEL);
-		if (!bitmap)
-			return -ENOMEM;
-
-		memset(bitmap, 0xff, IO_BITMAP_BYTES);
-		t->io_bitmap_ptr = bitmap;
-		set_thread_flag(TIF_IO_BITMAP);
-	}
-
-	/*
-	 * do it in the per-thread copy and in the TSS ...
-	 *
-	 * Disable preemption via get_cpu() - we must not switch away
-	 * because the ->io_bitmap_max value must match the bitmap
-	 * contents:
-	 */
-	tss = &per_cpu(init_tss, get_cpu());
-
-	set_bitmap(t->io_bitmap_ptr, from, num, !turn_on);
-
-	/*
-	 * Search for a (possibly new) maximum. This is simple and stupid,
-	 * to keep it obviously correct:
-	 */
-	max_long = 0;
-	for (i = 0; i < IO_BITMAP_LONGS; i++)
-		if (t->io_bitmap_ptr[i] != ~0UL)
-			max_long = i;
-
-	bytes = (max_long + 1) * sizeof(long);
-	bytes_updated = max(bytes, t->io_bitmap_max);
-
-	t->io_bitmap_max = bytes;
-
-	/* Update the TSS: */
-	memcpy(tss->io_bitmap, t->io_bitmap_ptr, bytes_updated);
-
-	put_cpu();
-
-	return 0;
-}
-
-/*
- * sys_iopl has to be used when you want to access the IO ports
- * beyond the 0x3ff range: to get the full 65536 ports bitmapped
- * you'd need 8kB of bitmaps/process, which is a bit excessive.
- *
- * Here we just change the flags value on the stack: we allow
- * only the super-user to do it. This depends on the stack-layout
- * on system-call entry - see also fork() and the signal handling
- * code.
- */
-
-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;
-}