diff options
Diffstat (limited to 'arch/x86/kernel/ioport_64.c')
| -rw-r--r-- | arch/x86/kernel/ioport_64.c | 117 |
1 files changed, 0 insertions, 117 deletions
diff --git a/arch/x86/kernel/ioport_64.c b/arch/x86/kernel/ioport_64.c deleted file mode 100644 index 5f62fad64da..00000000000 --- a/arch/x86/kernel/ioport_64.c +++ /dev/null @@ -1,117 +0,0 @@ -/* - * 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 eflags 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->eflags >> 12) & 3; - - if (level > 3) - return -EINVAL; - /* Trying to gain more privileges? */ - if (level > old) { - if (!capable(CAP_SYS_RAWIO)) - return -EPERM; - } - regs->eflags = (regs->eflags &~ X86_EFLAGS_IOPL) | (level << 12); - return 0; -} |