/*
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/*
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* linux/arch/i386/kernel/ioport.c
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* linux/arch/i386/kernel/ioport.c
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*
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*
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* This contains the io-permission bitmap code - written by obz, with changes
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* This contains the io-permission bitmap code - written by obz, with changes
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* by Linus.
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* by Linus.
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*/
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*/
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#include <linux/sched.h>
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#include <linux/sched.h>
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#include <linux/kernel.h>
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#include <linux/kernel.h>
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#include <linux/errno.h>
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#include <linux/errno.h>
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#include <linux/types.h>
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#include <linux/types.h>
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#include <linux/ioport.h>
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#include <linux/ioport.h>
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/* Set EXTENT bits starting at BASE in BITMAP to value TURN_ON. */
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/* Set EXTENT bits starting at BASE in BITMAP to value TURN_ON. */
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static void set_bitmap(unsigned long *bitmap, short base, short extent, int new_value)
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static void set_bitmap(unsigned long *bitmap, short base, short extent, int new_value)
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{
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{
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int mask;
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int mask;
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unsigned long *bitmap_base = bitmap + (base >> 5);
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unsigned long *bitmap_base = bitmap + (base >> 5);
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unsigned short low_index = base & 0x1f;
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unsigned short low_index = base & 0x1f;
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int length = low_index + extent;
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int length = low_index + extent;
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if (low_index != 0) {
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if (low_index != 0) {
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mask = (~0 << low_index);
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mask = (~0 << low_index);
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if (length < 32)
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if (length < 32)
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mask &= ~(~0 << length);
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mask &= ~(~0 << length);
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if (new_value)
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if (new_value)
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*bitmap_base++ |= mask;
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*bitmap_base++ |= mask;
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else
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else
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*bitmap_base++ &= ~mask;
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*bitmap_base++ &= ~mask;
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length -= 32;
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length -= 32;
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}
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}
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mask = (new_value ? ~0 : 0);
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mask = (new_value ? ~0 : 0);
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while (length >= 32) {
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while (length >= 32) {
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*bitmap_base++ = mask;
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*bitmap_base++ = mask;
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length -= 32;
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length -= 32;
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}
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}
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if (length > 0) {
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if (length > 0) {
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mask = ~(~0 << length);
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mask = ~(~0 << length);
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if (new_value)
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if (new_value)
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*bitmap_base++ |= mask;
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*bitmap_base++ |= mask;
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else
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else
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*bitmap_base++ &= ~mask;
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*bitmap_base++ &= ~mask;
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}
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}
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}
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}
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/*
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/*
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* this changes the io permissions bitmap in the current task.
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* this changes the io permissions bitmap in the current task.
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*/
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*/
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asmlinkage int sys_ioperm(unsigned long from, unsigned long num, int turn_on)
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asmlinkage int sys_ioperm(unsigned long from, unsigned long num, int turn_on)
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{
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{
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if (from + num <= from)
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if (from + num <= from)
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return -EINVAL;
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return -EINVAL;
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if (from + num > IO_BITMAP_SIZE*32)
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if (from + num > IO_BITMAP_SIZE*32)
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return -EINVAL;
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return -EINVAL;
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if (!suser() || securelevel > 0)
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if (!suser() || securelevel > 0)
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return -EPERM;
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return -EPERM;
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set_bitmap((unsigned long *)current->tss.io_bitmap, from, num, !turn_on);
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set_bitmap((unsigned long *)current->tss.io_bitmap, from, num, !turn_on);
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return 0;
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return 0;
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}
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}
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unsigned int *stack;
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unsigned int *stack;
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/*
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/*
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* sys_iopl has to be used when you want to access the IO ports
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* sys_iopl has to be used when you want to access the IO ports
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* beyond the 0x3ff range: to get the full 65536 ports bitmapped
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* beyond the 0x3ff range: to get the full 65536 ports bitmapped
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* you'd need 8kB of bitmaps/process, which is a bit excessive.
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* you'd need 8kB of bitmaps/process, which is a bit excessive.
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*
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*
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* Here we just change the eflags value on the stack: we allow
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* Here we just change the eflags value on the stack: we allow
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* only the super-user to do it. This depends on the stack-layout
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* only the super-user to do it. This depends on the stack-layout
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* on system-call entry - see also fork() and the signal handling
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* on system-call entry - see also fork() and the signal handling
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* code.
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* code.
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*/
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*/
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asmlinkage int sys_iopl(long ebx,long ecx,long edx,
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asmlinkage int sys_iopl(long ebx,long ecx,long edx,
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long esi, long edi, long ebp, long eax, long ds,
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long esi, long edi, long ebp, long eax, long ds,
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long es, long fs, long gs, long orig_eax,
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long es, long fs, long gs, long orig_eax,
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long eip,long cs,long eflags,long esp,long ss)
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long eip,long cs,long eflags,long esp,long ss)
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{
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{
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unsigned int level = ebx;
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unsigned int level = ebx;
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if (level > 3)
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if (level > 3)
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return -EINVAL;
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return -EINVAL;
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if (!suser() || securelevel > 0)
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if (!suser() || securelevel > 0)
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return -EPERM;
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return -EPERM;
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*(&eflags) = (eflags & 0xffffcfff) | (level << 12);
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*(&eflags) = (eflags & 0xffffcfff) | (level << 12);
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return 0;
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return 0;
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}
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}
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