ia64/xen-unstable

view linux-2.6-xen-sparse/arch/x86_64/kernel/ioport-xen.c @ 13647:057c4c2991fa

32-on-64: Fix an one-off error in compat_addr_ok().
Signed-off-by: Jan Beulich <jbeulich@novell.com>
author kaf24@localhost.localdomain
date Fri Jan 26 13:36:52 2007 +0000 (2007-01-26)
parents 28128dafbe03
children 8af1a8250c13
line source
1 /*
2 * linux/arch/x86_64/kernel/ioport.c
3 *
4 * This contains the io-permission bitmap code - written by obz, with changes
5 * by Linus.
6 */
8 #include <linux/sched.h>
9 #include <linux/kernel.h>
10 #include <linux/capability.h>
11 #include <linux/errno.h>
12 #include <linux/types.h>
13 #include <linux/ioport.h>
14 #include <linux/mm.h>
15 #include <linux/smp.h>
16 #include <linux/smp_lock.h>
17 #include <linux/stddef.h>
18 #include <linux/slab.h>
19 #include <linux/thread_info.h>
20 #include <xen/interface/physdev.h>
22 /* Set EXTENT bits starting at BASE in BITMAP to value TURN_ON. */
23 static void set_bitmap(unsigned long *bitmap, unsigned int base, unsigned int extent, int new_value)
24 {
25 int i;
27 if (new_value)
28 for (i = base; i < base + extent; i++)
29 __set_bit(i, bitmap);
30 else
31 for (i = base; i < base + extent; i++)
32 clear_bit(i, bitmap);
33 }
35 /*
36 * this changes the io permissions bitmap in the current task.
37 */
38 asmlinkage long sys_ioperm(unsigned long from, unsigned long num, int turn_on)
39 {
40 struct thread_struct * t = &current->thread;
41 unsigned long *bitmap;
42 struct physdev_set_iobitmap set_iobitmap;
44 if ((from + num <= from) || (from + num > IO_BITMAP_BITS))
45 return -EINVAL;
46 if (turn_on && !capable(CAP_SYS_RAWIO))
47 return -EPERM;
49 /*
50 * If it's the first ioperm() call in this thread's lifetime, set the
51 * IO bitmap up. ioperm() is much less timing critical than clone(),
52 * this is why we delay this operation until now:
53 */
54 if (!t->io_bitmap_ptr) {
55 bitmap = kmalloc(IO_BITMAP_BYTES, GFP_KERNEL);
56 if (!bitmap)
57 return -ENOMEM;
59 memset(bitmap, 0xff, IO_BITMAP_BYTES);
60 t->io_bitmap_ptr = bitmap;
62 set_iobitmap.bitmap = (char *)bitmap;
63 set_iobitmap.nr_ports = IO_BITMAP_BITS;
64 HYPERVISOR_physdev_op(PHYSDEVOP_set_iobitmap, &set_iobitmap);
65 }
67 set_bitmap(t->io_bitmap_ptr, from, num, !turn_on);
69 return 0;
70 }
72 /*
73 * sys_iopl has to be used when you want to access the IO ports
74 * beyond the 0x3ff range: to get the full 65536 ports bitmapped
75 * you'd need 8kB of bitmaps/process, which is a bit excessive.
76 *
77 */
79 asmlinkage long sys_iopl(unsigned int new_iopl, struct pt_regs *regs)
80 {
81 unsigned int old_iopl = current->thread.iopl;
82 struct physdev_set_iopl set_iopl;
84 if (new_iopl > 3)
85 return -EINVAL;
87 /* Need "raw I/O" privileges for direct port access. */
88 if ((new_iopl > old_iopl) && !capable(CAP_SYS_RAWIO))
89 return -EPERM;
91 /* Change our version of the privilege levels. */
92 current->thread.iopl = new_iopl;
94 /* Force the change at ring 0. */
95 set_iopl.iopl = (new_iopl == 0) ? 1 : new_iopl;
96 HYPERVISOR_physdev_op(PHYSDEVOP_set_iopl, &set_iopl);
98 return 0;
99 }