Merge branch 'master' of git://git.kernel.org/pub/scm/linux/kernel/git/linville/wirel...
[linux-2.6-block.git] / arch / sparc / kernel / sys_sparc_64.c
CommitLineData
207ddd0a 1/* linux/arch/sparc64/kernel/sys_sparc.c
1da177e4
LT
2 *
3 * This file contains various random system calls that
4 * have a non-standard calling sequence on the Linux/sparc
5 * platform.
6 */
7
1da177e4
LT
8#include <linux/errno.h>
9#include <linux/types.h>
10#include <linux/sched.h>
11#include <linux/fs.h>
12#include <linux/file.h>
13#include <linux/mm.h>
14#include <linux/sem.h>
15#include <linux/msg.h>
16#include <linux/shm.h>
17#include <linux/stat.h>
18#include <linux/mman.h>
19#include <linux/utsname.h>
20#include <linux/smp.h>
1da177e4
LT
21#include <linux/slab.h>
22#include <linux/syscalls.h>
23#include <linux/ipc.h>
24#include <linux/personality.h>
05f9ca83 25#include <linux/random.h>
066bcaca 26#include <linux/export.h>
812cb83a 27#include <linux/context_tracking.h>
1da177e4
LT
28
29#include <asm/uaccess.h>
1da177e4 30#include <asm/utrap.h>
fe74290d 31#include <asm/unistd.h>
1da177e4 32
207ddd0a 33#include "entry.h"
8df52620 34#include "kernel.h"
207ddd0a
DM
35#include "systbls.h"
36
1da177e4
LT
37/* #define DEBUG_UNIMP_SYSCALL */
38
1da177e4
LT
39asmlinkage unsigned long sys_getpagesize(void)
40{
41 return PAGE_SIZE;
42}
43
8bcd1741
DM
44/* Does addr --> addr+len fall within 4GB of the VA-space hole or
45 * overflow past the end of the 64-bit address space?
46 */
47static inline int invalid_64bit_range(unsigned long addr, unsigned long len)
48{
49 unsigned long va_exclude_start, va_exclude_end;
50
51 va_exclude_start = VA_EXCLUDE_START;
52 va_exclude_end = VA_EXCLUDE_END;
53
54 if (unlikely(len >= va_exclude_start))
55 return 1;
56
57 if (unlikely((addr + len) < addr))
58 return 1;
59
60 if (unlikely((addr >= va_exclude_start && addr < va_exclude_end) ||
61 ((addr + len) >= va_exclude_start &&
62 (addr + len) < va_exclude_end)))
63 return 1;
64
65 return 0;
66}
67
a91690dd
DM
68/* These functions differ from the default implementations in
69 * mm/mmap.c in two ways:
70 *
71 * 1) For file backed MAP_SHARED mmap()'s we D-cache color align,
72 * for fixed such mappings we just validate what the user gave us.
73 * 2) For 64-bit tasks we avoid mapping anything within 4GB of
74 * the spitfire/niagara VA-hole.
75 */
76
748ba883 77static inline unsigned long COLOR_ALIGN(unsigned long addr,
a91690dd
DM
78 unsigned long pgoff)
79{
80 unsigned long base = (addr+SHMLBA-1)&~(SHMLBA-1);
81 unsigned long off = (pgoff<<PAGE_SHIFT) & (SHMLBA-1);
82
83 return base + off;
84}
85
1da177e4
LT
86unsigned long arch_get_unmapped_area(struct file *filp, unsigned long addr, unsigned long len, unsigned long pgoff, unsigned long flags)
87{
88 struct mm_struct *mm = current->mm;
89 struct vm_area_struct * vma;
90 unsigned long task_size = TASK_SIZE;
1da177e4 91 int do_color_align;
bb64f550 92 struct vm_unmapped_area_info info;
1da177e4
LT
93
94 if (flags & MAP_FIXED) {
95 /* We do not accept a shared mapping if it would violate
96 * cache aliasing constraints.
97 */
98 if ((flags & MAP_SHARED) &&
99 ((addr - (pgoff << PAGE_SHIFT)) & (SHMLBA - 1)))
100 return -EINVAL;
101 return addr;
102 }
103
104 if (test_thread_flag(TIF_32BIT))
d61e16df 105 task_size = STACK_TOP32;
a91690dd 106 if (unlikely(len > task_size || len >= VA_EXCLUDE_START))
1da177e4
LT
107 return -ENOMEM;
108
109 do_color_align = 0;
110 if (filp || (flags & MAP_SHARED))
111 do_color_align = 1;
112
113 if (addr) {
114 if (do_color_align)
748ba883 115 addr = COLOR_ALIGN(addr, pgoff);
1da177e4
LT
116 else
117 addr = PAGE_ALIGN(addr);
118
119 vma = find_vma(mm, addr);
120 if (task_size - len >= addr &&
121 (!vma || addr + len <= vma->vm_start))
122 return addr;
123 }
124
bb64f550
ML
125 info.flags = 0;
126 info.length = len;
127 info.low_limit = TASK_UNMAPPED_BASE;
128 info.high_limit = min(task_size, VA_EXCLUDE_START);
129 info.align_mask = do_color_align ? (PAGE_MASK & (SHMLBA - 1)) : 0;
130 info.align_offset = pgoff << PAGE_SHIFT;
131 addr = vm_unmapped_area(&info);
132
133 if ((addr & ~PAGE_MASK) && task_size > VA_EXCLUDE_END) {
134 VM_BUG_ON(addr != -ENOMEM);
135 info.low_limit = VA_EXCLUDE_END;
136 info.high_limit = task_size;
137 addr = vm_unmapped_area(&info);
1363c3cd 138 }
1da177e4 139
bb64f550 140 return addr;
1da177e4
LT
141}
142
a91690dd
DM
143unsigned long
144arch_get_unmapped_area_topdown(struct file *filp, const unsigned long addr0,
145 const unsigned long len, const unsigned long pgoff,
146 const unsigned long flags)
147{
148 struct vm_area_struct *vma;
149 struct mm_struct *mm = current->mm;
d61e16df 150 unsigned long task_size = STACK_TOP32;
a91690dd
DM
151 unsigned long addr = addr0;
152 int do_color_align;
bb64f550 153 struct vm_unmapped_area_info info;
a91690dd
DM
154
155 /* This should only ever run for 32-bit processes. */
156 BUG_ON(!test_thread_flag(TIF_32BIT));
157
158 if (flags & MAP_FIXED) {
159 /* We do not accept a shared mapping if it would violate
160 * cache aliasing constraints.
161 */
162 if ((flags & MAP_SHARED) &&
163 ((addr - (pgoff << PAGE_SHIFT)) & (SHMLBA - 1)))
164 return -EINVAL;
165 return addr;
166 }
167
168 if (unlikely(len > task_size))
169 return -ENOMEM;
170
171 do_color_align = 0;
172 if (filp || (flags & MAP_SHARED))
173 do_color_align = 1;
174
175 /* requesting a specific address */
176 if (addr) {
177 if (do_color_align)
748ba883 178 addr = COLOR_ALIGN(addr, pgoff);
a91690dd
DM
179 else
180 addr = PAGE_ALIGN(addr);
181
182 vma = find_vma(mm, addr);
183 if (task_size - len >= addr &&
184 (!vma || addr + len <= vma->vm_start))
185 return addr;
186 }
187
bb64f550
ML
188 info.flags = VM_UNMAPPED_AREA_TOPDOWN;
189 info.length = len;
190 info.low_limit = PAGE_SIZE;
191 info.high_limit = mm->mmap_base;
192 info.align_mask = do_color_align ? (PAGE_MASK & (SHMLBA - 1)) : 0;
193 info.align_offset = pgoff << PAGE_SHIFT;
194 addr = vm_unmapped_area(&info);
a91690dd 195
a91690dd
DM
196 /*
197 * A failed mmap() very likely causes application failure,
198 * so fall back to the bottom-up function here. This scenario
199 * can happen with large stack limits and large mmap()
200 * allocations.
201 */
bb64f550
ML
202 if (addr & ~PAGE_MASK) {
203 VM_BUG_ON(addr != -ENOMEM);
204 info.flags = 0;
205 info.low_limit = TASK_UNMAPPED_BASE;
206 info.high_limit = STACK_TOP32;
207 addr = vm_unmapped_area(&info);
208 }
a91690dd
DM
209
210 return addr;
211}
212
1da177e4
LT
213/* Try to align mapping such that we align it as much as possible. */
214unsigned long get_fb_unmapped_area(struct file *filp, unsigned long orig_addr, unsigned long len, unsigned long pgoff, unsigned long flags)
215{
216 unsigned long align_goal, addr = -ENOMEM;
c4caa778
AV
217 unsigned long (*get_area)(struct file *, unsigned long,
218 unsigned long, unsigned long, unsigned long);
219
220 get_area = current->mm->get_unmapped_area;
1da177e4
LT
221
222 if (flags & MAP_FIXED) {
223 /* Ok, don't mess with it. */
c4caa778 224 return get_area(NULL, orig_addr, len, pgoff, flags);
1da177e4
LT
225 }
226 flags &= ~MAP_SHARED;
227
228 align_goal = PAGE_SIZE;
229 if (len >= (4UL * 1024 * 1024))
230 align_goal = (4UL * 1024 * 1024);
231 else if (len >= (512UL * 1024))
232 align_goal = (512UL * 1024);
233 else if (len >= (64UL * 1024))
234 align_goal = (64UL * 1024);
235
236 do {
c4caa778 237 addr = get_area(NULL, orig_addr, len + (align_goal - PAGE_SIZE), pgoff, flags);
1da177e4
LT
238 if (!(addr & ~PAGE_MASK)) {
239 addr = (addr + (align_goal - 1UL)) & ~(align_goal - 1UL);
240 break;
241 }
242
243 if (align_goal == (4UL * 1024 * 1024))
244 align_goal = (512UL * 1024);
245 else if (align_goal == (512UL * 1024))
246 align_goal = (64UL * 1024);
247 else
248 align_goal = PAGE_SIZE;
249 } while ((addr & ~PAGE_MASK) && align_goal > PAGE_SIZE);
250
251 /* Mapping is smaller than 64K or larger areas could not
252 * be obtained.
253 */
254 if (addr & ~PAGE_MASK)
c4caa778 255 addr = get_area(NULL, orig_addr, len, pgoff, flags);
1da177e4
LT
256
257 return addr;
258}
917c3660 259EXPORT_SYMBOL(get_fb_unmapped_area);
1da177e4 260
5a0efea0
DM
261/* Essentially the same as PowerPC. */
262static unsigned long mmap_rnd(void)
a91690dd 263{
5a0efea0 264 unsigned long rnd = 0UL;
05f9ca83
DM
265
266 if (current->flags & PF_RANDOMIZE) {
5a0efea0 267 unsigned long val = get_random_int();
05f9ca83 268 if (test_thread_flag(TIF_32BIT))
fa8cbaaf 269 rnd = (val % (1UL << (23UL-PAGE_SHIFT)));
05f9ca83 270 else
fa8cbaaf 271 rnd = (val % (1UL << (30UL-PAGE_SHIFT)));
05f9ca83 272 }
fa8cbaaf 273 return rnd << PAGE_SHIFT;
5a0efea0
DM
274}
275
276void arch_pick_mmap_layout(struct mm_struct *mm)
277{
278 unsigned long random_factor = mmap_rnd();
279 unsigned long gap;
05f9ca83 280
a91690dd
DM
281 /*
282 * Fall back to the standard layout if the personality
283 * bit is set, or if the expected stack growth is unlimited:
284 */
76704fb5 285 gap = rlimit(RLIMIT_STACK);
a91690dd
DM
286 if (!test_thread_flag(TIF_32BIT) ||
287 (current->personality & ADDR_COMPAT_LAYOUT) ||
76704fb5 288 gap == RLIM_INFINITY ||
a91690dd 289 sysctl_legacy_va_layout) {
05f9ca83 290 mm->mmap_base = TASK_UNMAPPED_BASE + random_factor;
a91690dd 291 mm->get_unmapped_area = arch_get_unmapped_area;
a91690dd
DM
292 } else {
293 /* We know it's 32-bit */
d61e16df 294 unsigned long task_size = STACK_TOP32;
a91690dd 295
a91690dd
DM
296 if (gap < 128 * 1024 * 1024)
297 gap = 128 * 1024 * 1024;
298 if (gap > (task_size / 6 * 5))
299 gap = (task_size / 6 * 5);
300
05f9ca83 301 mm->mmap_base = PAGE_ALIGN(task_size - gap - random_factor);
a91690dd 302 mm->get_unmapped_area = arch_get_unmapped_area_topdown;
a91690dd
DM
303 }
304}
305
1da177e4
LT
306/*
307 * sys_pipe() is the normal C calling standard for creating
308 * a pipe. It's not the way unix traditionally does this, though.
309 */
e4265019 310SYSCALL_DEFINE1(sparc_pipe_real, struct pt_regs *, regs)
1da177e4
LT
311{
312 int fd[2];
313 int error;
314
ed8cae8b 315 error = do_pipe_flags(fd, 0);
1da177e4
LT
316 if (error)
317 goto out;
318 regs->u_regs[UREG_I1] = fd[1];
319 error = fd[0];
320out:
321 return error;
322}
323
324/*
325 * sys_ipc() is the de-multiplexer for the SysV IPC calls..
326 *
327 * This is really horribly ugly.
328 */
329
baed7fc9 330SYSCALL_DEFINE6(sparc_ipc, unsigned int, call, int, first, unsigned long, second,
e4265019 331 unsigned long, third, void __user *, ptr, long, fifth)
1da177e4 332{
7379b42b 333 long err;
1da177e4
LT
334
335 /* No need for backward compatibility. We can start fresh... */
336 if (call <= SEMCTL) {
337 switch (call) {
338 case SEMOP:
339 err = sys_semtimedop(first, ptr,
340 (unsigned)second, NULL);
341 goto out;
342 case SEMTIMEDOP:
343 err = sys_semtimedop(first, ptr, (unsigned)second,
207ddd0a
DM
344 (const struct timespec __user *)
345 (unsigned long) fifth);
1da177e4
LT
346 goto out;
347 case SEMGET:
348 err = sys_semget(first, (int)second, (int)third);
349 goto out;
350 case SEMCTL: {
020cfb05
DM
351 err = sys_semctl(first, second,
352 (int)third | IPC_64,
e1fd1f49 353 (unsigned long) ptr);
1da177e4
LT
354 goto out;
355 }
356 default:
357 err = -ENOSYS;
358 goto out;
6cb79b3f 359 }
1da177e4
LT
360 }
361 if (call <= MSGCTL) {
362 switch (call) {
363 case MSGSND:
364 err = sys_msgsnd(first, ptr, (size_t)second,
365 (int)third);
366 goto out;
367 case MSGRCV:
368 err = sys_msgrcv(first, ptr, (size_t)second, fifth,
369 (int)third);
370 goto out;
371 case MSGGET:
372 err = sys_msgget((key_t)first, (int)second);
373 goto out;
374 case MSGCTL:
375 err = sys_msgctl(first, (int)second | IPC_64, ptr);
376 goto out;
377 default:
378 err = -ENOSYS;
379 goto out;
6cb79b3f 380 }
1da177e4
LT
381 }
382 if (call <= SHMCTL) {
383 switch (call) {
384 case SHMAT: {
385 ulong raddr;
079a96ae 386 err = do_shmat(first, ptr, (int)second, &raddr, SHMLBA);
1da177e4
LT
387 if (!err) {
388 if (put_user(raddr,
389 (ulong __user *) third))
390 err = -EFAULT;
391 }
392 goto out;
393 }
394 case SHMDT:
395 err = sys_shmdt(ptr);
396 goto out;
397 case SHMGET:
398 err = sys_shmget(first, (size_t)second, (int)third);
399 goto out;
400 case SHMCTL:
401 err = sys_shmctl(first, (int)second | IPC_64, ptr);
402 goto out;
403 default:
404 err = -ENOSYS;
405 goto out;
6cb79b3f 406 }
1da177e4
LT
407 } else {
408 err = -ENOSYS;
409 }
410out:
411 return err;
412}
413
e4265019 414SYSCALL_DEFINE1(sparc64_personality, unsigned long, personality)
1da177e4
LT
415{
416 int ret;
417
a27032ee
JK
418 if (personality(current->personality) == PER_LINUX32 &&
419 personality(personality) == PER_LINUX)
420 personality |= PER_LINUX32;
1da177e4 421 ret = sys_personality(personality);
a27032ee
JK
422 if (personality(ret) == PER_LINUX32)
423 ret &= ~PER_LINUX32;
1da177e4
LT
424
425 return ret;
426}
427
f92ffa12 428int sparc_mmap_check(unsigned long addr, unsigned long len)
3a459756
KK
429{
430 if (test_thread_flag(TIF_32BIT)) {
431 if (len >= STACK_TOP32)
432 return -EINVAL;
433
58163393 434 if (addr > STACK_TOP32 - len)
3a459756
KK
435 return -EINVAL;
436 } else {
437 if (len >= VA_EXCLUDE_START)
438 return -EINVAL;
439
58163393 440 if (invalid_64bit_range(addr, len))
3a459756
KK
441 return -EINVAL;
442 }
443
444 return 0;
445}
446
1da177e4 447/* Linux version of mmap */
e4265019
DM
448SYSCALL_DEFINE6(mmap, unsigned long, addr, unsigned long, len,
449 unsigned long, prot, unsigned long, flags, unsigned long, fd,
450 unsigned long, off)
1da177e4 451{
f8b72560 452 unsigned long retval = -EINVAL;
1da177e4 453
f8b72560
AV
454 if ((off + PAGE_ALIGN(len)) < off)
455 goto out;
456 if (off & ~PAGE_MASK)
457 goto out;
458 retval = sys_mmap_pgoff(addr, len, prot, flags, fd, off >> PAGE_SHIFT);
1da177e4
LT
459out:
460 return retval;
461}
462
e4265019 463SYSCALL_DEFINE2(64_munmap, unsigned long, addr, size_t, len)
1da177e4 464{
8bcd1741 465 if (invalid_64bit_range(addr, len))
1da177e4 466 return -EINVAL;
8bcd1741 467
bfce281c 468 return vm_munmap(addr, len);
1da177e4 469}
1da177e4 470
e4265019
DM
471SYSCALL_DEFINE5(64_mremap, unsigned long, addr, unsigned long, old_len,
472 unsigned long, new_len, unsigned long, flags,
473 unsigned long, new_addr)
1da177e4 474{
1da177e4 475 if (test_thread_flag(TIF_32BIT))
657bec85
AV
476 return -EINVAL;
477 return sys_mremap(addr, old_len, new_len, flags, new_addr);
1da177e4
LT
478}
479
480/* we come to here via sys_nis_syscall so it can setup the regs argument */
481asmlinkage unsigned long c_sys_nis_syscall(struct pt_regs *regs)
482{
483 static int count;
484
485 /* Don't make the system unusable, if someone goes stuck */
486 if (count++ > 5)
487 return -ENOSYS;
488
489 printk ("Unimplemented SPARC system call %ld\n",regs->u_regs[1]);
490#ifdef DEBUG_UNIMP_SYSCALL
491 show_regs (regs);
492#endif
493
494 return -ENOSYS;
495}
496
497/* #define DEBUG_SPARC_BREAKPOINT */
498
499asmlinkage void sparc_breakpoint(struct pt_regs *regs)
500{
812cb83a 501 enum ctx_state prev_state = exception_enter();
1da177e4
LT
502 siginfo_t info;
503
504 if (test_thread_flag(TIF_32BIT)) {
505 regs->tpc &= 0xffffffff;
506 regs->tnpc &= 0xffffffff;
507 }
508#ifdef DEBUG_SPARC_BREAKPOINT
509 printk ("TRAP: Entering kernel PC=%lx, nPC=%lx\n", regs->tpc, regs->tnpc);
510#endif
511 info.si_signo = SIGTRAP;
512 info.si_errno = 0;
513 info.si_code = TRAP_BRKPT;
514 info.si_addr = (void __user *)regs->tpc;
515 info.si_trapno = 0;
516 force_sig_info(SIGTRAP, &info, current);
517#ifdef DEBUG_SPARC_BREAKPOINT
518 printk ("TRAP: Returning to space: PC=%lx nPC=%lx\n", regs->tpc, regs->tnpc);
519#endif
812cb83a 520 exception_exit(prev_state);
1da177e4
LT
521}
522
523extern void check_pending(int signum);
524
e4265019 525SYSCALL_DEFINE2(getdomainname, char __user *, name, int, len)
1da177e4 526{
8310a32c
DM
527 int nlen, err;
528
b9c54f91 529 if (len < 0)
8310a32c 530 return -EINVAL;
1da177e4
LT
531
532 down_read(&uts_sem);
533
e9ff3990 534 nlen = strlen(utsname()->domainname) + 1;
b9c54f91
AW
535 err = -EINVAL;
536 if (nlen > len)
537 goto out;
8310a32c
DM
538
539 err = -EFAULT;
e9ff3990 540 if (!copy_to_user(name, utsname()->domainname, nlen))
8310a32c
DM
541 err = 0;
542
b9c54f91 543out:
1da177e4
LT
544 up_read(&uts_sem);
545 return err;
546}
547
e4265019
DM
548SYSCALL_DEFINE5(utrap_install, utrap_entry_t, type,
549 utrap_handler_t, new_p, utrap_handler_t, new_d,
550 utrap_handler_t __user *, old_p,
551 utrap_handler_t __user *, old_d)
1da177e4
LT
552{
553 if (type < UT_INSTRUCTION_EXCEPTION || type > UT_TRAP_INSTRUCTION_31)
554 return -EINVAL;
555 if (new_p == (utrap_handler_t)(long)UTH_NOCHANGE) {
556 if (old_p) {
557 if (!current_thread_info()->utraps) {
558 if (put_user(NULL, old_p))
559 return -EFAULT;
560 } else {
561 if (put_user((utrap_handler_t)(current_thread_info()->utraps[type]), old_p))
562 return -EFAULT;
563 }
564 }
565 if (old_d) {
566 if (put_user(NULL, old_d))
567 return -EFAULT;
568 }
569 return 0;
570 }
571 if (!current_thread_info()->utraps) {
572 current_thread_info()->utraps =
9132983a 573 kzalloc((UT_TRAP_INSTRUCTION_31+1)*sizeof(long), GFP_KERNEL);
1da177e4
LT
574 if (!current_thread_info()->utraps)
575 return -ENOMEM;
576 current_thread_info()->utraps[0] = 1;
1da177e4
LT
577 } else {
578 if ((utrap_handler_t)current_thread_info()->utraps[type] != new_p &&
579 current_thread_info()->utraps[0] > 1) {
207ddd0a 580 unsigned long *p = current_thread_info()->utraps;
1da177e4
LT
581
582 current_thread_info()->utraps =
583 kmalloc((UT_TRAP_INSTRUCTION_31+1)*sizeof(long),
584 GFP_KERNEL);
585 if (!current_thread_info()->utraps) {
586 current_thread_info()->utraps = p;
587 return -ENOMEM;
588 }
589 p[0]--;
590 current_thread_info()->utraps[0] = 1;
591 memcpy(current_thread_info()->utraps+1, p+1,
592 UT_TRAP_INSTRUCTION_31*sizeof(long));
593 }
594 }
595 if (old_p) {
596 if (put_user((utrap_handler_t)(current_thread_info()->utraps[type]), old_p))
597 return -EFAULT;
598 }
599 if (old_d) {
600 if (put_user(NULL, old_d))
601 return -EFAULT;
602 }
603 current_thread_info()->utraps[type] = (long)new_p;
604
605 return 0;
606}
607
207ddd0a
DM
608asmlinkage long sparc_memory_ordering(unsigned long model,
609 struct pt_regs *regs)
1da177e4
LT
610{
611 if (model >= 3)
612 return -EINVAL;
613 regs->tstate = (regs->tstate & ~TSTATE_MM) | (model << 14);
614 return 0;
615}
616
e4265019
DM
617SYSCALL_DEFINE5(rt_sigaction, int, sig, const struct sigaction __user *, act,
618 struct sigaction __user *, oact, void __user *, restorer,
619 size_t, sigsetsize)
1da177e4
LT
620{
621 struct k_sigaction new_ka, old_ka;
622 int ret;
623
624 /* XXX: Don't preclude handling different sized sigset_t's. */
625 if (sigsetsize != sizeof(sigset_t))
626 return -EINVAL;
627
628 if (act) {
629 new_ka.ka_restorer = restorer;
630 if (copy_from_user(&new_ka.sa, act, sizeof(*act)))
631 return -EFAULT;
632 }
633
634 ret = do_sigaction(sig, act ? &new_ka : NULL, oact ? &old_ka : NULL);
635
636 if (!ret && oact) {
637 if (copy_to_user(oact, &old_ka.sa, sizeof(*oact)))
638 return -EFAULT;
639 }
640
641 return ret;
642}
643
517ffce4
DM
644asmlinkage long sys_kern_features(void)
645{
646 return KERN_FEATURE_MIXED_MODE_STACK;
647}