Contributors: 23
| Author |
Tokens |
Token Proportion |
Commits |
Commit Proportion |
| Linus Torvalds (pre-git) |
133 |
29.82% |
11 |
28.21% |
| Miguel Botón |
52 |
11.66% |
1 |
2.56% |
| Ingo Molnar |
46 |
10.31% |
2 |
5.13% |
| Dominik Brodowski |
42 |
9.42% |
1 |
2.56% |
| Andrew Lutomirski |
27 |
6.05% |
4 |
10.26% |
| Brian Gerst |
22 |
4.93% |
2 |
5.13% |
| Benjamin LaHaise |
20 |
4.48% |
1 |
2.56% |
| Akinobu Mita |
20 |
4.48% |
1 |
2.56% |
| Chris Wright |
14 |
3.14% |
2 |
5.13% |
| Al Viro |
13 |
2.91% |
1 |
2.56% |
| Thomas Gleixner |
12 |
2.69% |
1 |
2.56% |
| Albert D. Cahalan |
7 |
1.57% |
1 |
2.56% |
| Andrew Morton |
6 |
1.35% |
1 |
2.56% |
| Shai Fultheim |
5 |
1.12% |
1 |
2.56% |
| Stéphane Eranian |
5 |
1.12% |
1 |
2.56% |
| Zachary Amsden |
5 |
1.12% |
1 |
2.56% |
| Robert Love |
4 |
0.90% |
1 |
2.56% |
| Adrian Bunk |
3 |
0.67% |
1 |
2.56% |
| Randy Dunlap |
3 |
0.67% |
1 |
2.56% |
| Linus Torvalds |
3 |
0.67% |
1 |
2.56% |
| Jaswinder Singh Rajput |
2 |
0.45% |
1 |
2.56% |
| H. Peter Anvin |
1 |
0.22% |
1 |
2.56% |
| Greg Kroah-Hartman |
1 |
0.22% |
1 |
2.56% |
| Total |
446 |
|
39 |
|
// SPDX-License-Identifier: GPL-2.0
/*
* This contains the io-permission bitmap code - written by obz, with changes
* by Linus. 32/64 bits code unification by Miguel Botón.
*/
#include <linux/sched.h>
#include <linux/sched/task_stack.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>
#include <linux/bitmap.h>
#include <asm/syscalls.h>
#include <asm/desc.h>
/*
* this changes the io permissions bitmap in the current task.
*/
long ksys_ioperm(unsigned long from, unsigned long num, int turn_on)
{
struct thread_struct *t = ¤t->thread;
struct tss_struct *tss;
unsigned int i, max_long, bytes, bytes_updated;
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) {
unsigned long *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);
/*
* Now that we have an IO bitmap, we need our TSS limit to be
* correct. It's fine if we are preempted after doing this:
* with TIF_IO_BITMAP set, context switches will keep our TSS
* limit correct.
*/
preempt_disable();
refresh_tss_limit();
preempt_enable();
}
/*
* 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(cpu_tss_rw, get_cpu());
if (turn_on)
bitmap_clear(t->io_bitmap_ptr, from, num);
else
bitmap_set(t->io_bitmap_ptr, from, num);
/*
* 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(unsigned 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;
}
SYSCALL_DEFINE3(ioperm, unsigned long, from, unsigned long, num, int, turn_on)
{
return ksys_ioperm(from, num, turn_on);
}
/*
* 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.
*/
SYSCALL_DEFINE1(iopl, unsigned int, level)
{
struct pt_regs *regs = current_pt_regs();
struct thread_struct *t = ¤t->thread;
/*
* Careful: the IOPL bits in regs->flags are undefined under Xen PV
* and changing them has no effect.
*/
unsigned int old = t->iopl >> X86_EFLAGS_IOPL_BIT;
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 << X86_EFLAGS_IOPL_BIT);
t->iopl = level << X86_EFLAGS_IOPL_BIT;
set_iopl_mask(t->iopl);
return 0;
}