65ea5b0349
We have a lot of code which differs only by the naming of specific members of structures that contain registers. In order to enable additional unifications, this patch drops the e- or r- size prefix from the register names in struct pt_regs, and drops the x- prefixes for segment registers on the 32-bit side. This patch also performs the equivalent renames in some additional places that might be candidates for unification in the future. Signed-off-by: H. Peter Anvin <hpa@zytor.com> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
118 lines
3.0 KiB
C
118 lines
3.0 KiB
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 = ¤t->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;
|
|
}
|