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1/* linux/arch/sparc64/kernel/sys_sparc.c
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
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>
21#include <linux/slab.h>
22#include <linux/syscalls.h>
23#include <linux/ipc.h>
24#include <linux/personality.h>
25#include <linux/random.h>
26#include <linux/export.h>
27
28#include <asm/uaccess.h>
29#include <asm/utrap.h>
30#include <asm/unistd.h>
31
32#include "entry.h"
33#include "systbls.h"
34
35/* #define DEBUG_UNIMP_SYSCALL */
36
37asmlinkage unsigned long sys_getpagesize(void)
38{
39 return PAGE_SIZE;
40}
41
42#define VA_EXCLUDE_START (0x0000080000000000UL - (1UL << 32UL))
43#define VA_EXCLUDE_END (0xfffff80000000000UL + (1UL << 32UL))
44
45/* Does addr --> addr+len fall within 4GB of the VA-space hole or
46 * overflow past the end of the 64-bit address space?
47 */
48static inline int invalid_64bit_range(unsigned long addr, unsigned long len)
49{
50 unsigned long va_exclude_start, va_exclude_end;
51
52 va_exclude_start = VA_EXCLUDE_START;
53 va_exclude_end = VA_EXCLUDE_END;
54
55 if (unlikely(len >= va_exclude_start))
56 return 1;
57
58 if (unlikely((addr + len) < addr))
59 return 1;
60
61 if (unlikely((addr >= va_exclude_start && addr < va_exclude_end) ||
62 ((addr + len) >= va_exclude_start &&
63 (addr + len) < va_exclude_end)))
64 return 1;
65
66 return 0;
67}
68
69/* Does start,end straddle the VA-space hole? */
70static inline int straddles_64bit_va_hole(unsigned long start, unsigned long end)
71{
72 unsigned long va_exclude_start, va_exclude_end;
73
74 va_exclude_start = VA_EXCLUDE_START;
75 va_exclude_end = VA_EXCLUDE_END;
76
77 if (likely(start < va_exclude_start && end < va_exclude_start))
78 return 0;
79
80 if (likely(start >= va_exclude_end && end >= va_exclude_end))
81 return 0;
82
83 return 1;
84}
85
86/* These functions differ from the default implementations in
87 * mm/mmap.c in two ways:
88 *
89 * 1) For file backed MAP_SHARED mmap()'s we D-cache color align,
90 * for fixed such mappings we just validate what the user gave us.
91 * 2) For 64-bit tasks we avoid mapping anything within 4GB of
92 * the spitfire/niagara VA-hole.
93 */
94
95static inline unsigned long COLOUR_ALIGN(unsigned long addr,
96 unsigned long pgoff)
97{
98 unsigned long base = (addr+SHMLBA-1)&~(SHMLBA-1);
99 unsigned long off = (pgoff<<PAGE_SHIFT) & (SHMLBA-1);
100
101 return base + off;
102}
103
104static inline unsigned long COLOUR_ALIGN_DOWN(unsigned long addr,
105 unsigned long pgoff)
106{
107 unsigned long base = addr & ~(SHMLBA-1);
108 unsigned long off = (pgoff<<PAGE_SHIFT) & (SHMLBA-1);
109
110 if (base + off <= addr)
111 return base + off;
112 return base - off;
113}
114
115unsigned long arch_get_unmapped_area(struct file *filp, unsigned long addr, unsigned long len, unsigned long pgoff, unsigned long flags)
116{
117 struct mm_struct *mm = current->mm;
118 struct vm_area_struct * vma;
119 unsigned long task_size = TASK_SIZE;
120 unsigned long start_addr;
121 int do_color_align;
122
123 if (flags & MAP_FIXED) {
124 /* We do not accept a shared mapping if it would violate
125 * cache aliasing constraints.
126 */
127 if ((flags & MAP_SHARED) &&
128 ((addr - (pgoff << PAGE_SHIFT)) & (SHMLBA - 1)))
129 return -EINVAL;
130 return addr;
131 }
132
133 if (test_thread_flag(TIF_32BIT))
134 task_size = STACK_TOP32;
135 if (unlikely(len > task_size || len >= VA_EXCLUDE_START))
136 return -ENOMEM;
137
138 do_color_align = 0;
139 if (filp || (flags & MAP_SHARED))
140 do_color_align = 1;
141
142 if (addr) {
143 if (do_color_align)
144 addr = COLOUR_ALIGN(addr, pgoff);
145 else
146 addr = PAGE_ALIGN(addr);
147
148 vma = find_vma(mm, addr);
149 if (task_size - len >= addr &&
150 (!vma || addr + len <= vma->vm_start))
151 return addr;
152 }
153
154 if (len > mm->cached_hole_size) {
155 start_addr = addr = mm->free_area_cache;
156 } else {
157 start_addr = addr = TASK_UNMAPPED_BASE;
158 mm->cached_hole_size = 0;
159 }
160
161 task_size -= len;
162
163full_search:
164 if (do_color_align)
165 addr = COLOUR_ALIGN(addr, pgoff);
166 else
167 addr = PAGE_ALIGN(addr);
168
169 for (vma = find_vma(mm, addr); ; vma = vma->vm_next) {
170 /* At this point: (!vma || addr < vma->vm_end). */
171 if (addr < VA_EXCLUDE_START &&
172 (addr + len) >= VA_EXCLUDE_START) {
173 addr = VA_EXCLUDE_END;
174 vma = find_vma(mm, VA_EXCLUDE_END);
175 }
176 if (unlikely(task_size < addr)) {
177 if (start_addr != TASK_UNMAPPED_BASE) {
178 start_addr = addr = TASK_UNMAPPED_BASE;
179 mm->cached_hole_size = 0;
180 goto full_search;
181 }
182 return -ENOMEM;
183 }
184 if (likely(!vma || addr + len <= vma->vm_start)) {
185 /*
186 * Remember the place where we stopped the search:
187 */
188 mm->free_area_cache = addr + len;
189 return addr;
190 }
191 if (addr + mm->cached_hole_size < vma->vm_start)
192 mm->cached_hole_size = vma->vm_start - addr;
193
194 addr = vma->vm_end;
195 if (do_color_align)
196 addr = COLOUR_ALIGN(addr, pgoff);
197 }
198}
199
200unsigned long
201arch_get_unmapped_area_topdown(struct file *filp, const unsigned long addr0,
202 const unsigned long len, const unsigned long pgoff,
203 const unsigned long flags)
204{
205 struct vm_area_struct *vma;
206 struct mm_struct *mm = current->mm;
207 unsigned long task_size = STACK_TOP32;
208 unsigned long addr = addr0;
209 int do_color_align;
210
211 /* This should only ever run for 32-bit processes. */
212 BUG_ON(!test_thread_flag(TIF_32BIT));
213
214 if (flags & MAP_FIXED) {
215 /* We do not accept a shared mapping if it would violate
216 * cache aliasing constraints.
217 */
218 if ((flags & MAP_SHARED) &&
219 ((addr - (pgoff << PAGE_SHIFT)) & (SHMLBA - 1)))
220 return -EINVAL;
221 return addr;
222 }
223
224 if (unlikely(len > task_size))
225 return -ENOMEM;
226
227 do_color_align = 0;
228 if (filp || (flags & MAP_SHARED))
229 do_color_align = 1;
230
231 /* requesting a specific address */
232 if (addr) {
233 if (do_color_align)
234 addr = COLOUR_ALIGN(addr, pgoff);
235 else
236 addr = PAGE_ALIGN(addr);
237
238 vma = find_vma(mm, addr);
239 if (task_size - len >= addr &&
240 (!vma || addr + len <= vma->vm_start))
241 return addr;
242 }
243
244 /* check if free_area_cache is useful for us */
245 if (len <= mm->cached_hole_size) {
246 mm->cached_hole_size = 0;
247 mm->free_area_cache = mm->mmap_base;
248 }
249
250 /* either no address requested or can't fit in requested address hole */
251 addr = mm->free_area_cache;
252 if (do_color_align) {
253 unsigned long base = COLOUR_ALIGN_DOWN(addr-len, pgoff);
254
255 addr = base + len;
256 }
257
258 /* make sure it can fit in the remaining address space */
259 if (likely(addr > len)) {
260 vma = find_vma(mm, addr-len);
261 if (!vma || addr <= vma->vm_start) {
262 /* remember the address as a hint for next time */
263 return (mm->free_area_cache = addr-len);
264 }
265 }
266
267 if (unlikely(mm->mmap_base < len))
268 goto bottomup;
269
270 addr = mm->mmap_base-len;
271 if (do_color_align)
272 addr = COLOUR_ALIGN_DOWN(addr, pgoff);
273
274 do {
275 /*
276 * Lookup failure means no vma is above this address,
277 * else if new region fits below vma->vm_start,
278 * return with success:
279 */
280 vma = find_vma(mm, addr);
281 if (likely(!vma || addr+len <= vma->vm_start)) {
282 /* remember the address as a hint for next time */
283 return (mm->free_area_cache = addr);
284 }
285
286 /* remember the largest hole we saw so far */
287 if (addr + mm->cached_hole_size < vma->vm_start)
288 mm->cached_hole_size = vma->vm_start - addr;
289
290 /* try just below the current vma->vm_start */
291 addr = vma->vm_start-len;
292 if (do_color_align)
293 addr = COLOUR_ALIGN_DOWN(addr, pgoff);
294 } while (likely(len < vma->vm_start));
295
296bottomup:
297 /*
298 * A failed mmap() very likely causes application failure,
299 * so fall back to the bottom-up function here. This scenario
300 * can happen with large stack limits and large mmap()
301 * allocations.
302 */
303 mm->cached_hole_size = ~0UL;
304 mm->free_area_cache = TASK_UNMAPPED_BASE;
305 addr = arch_get_unmapped_area(filp, addr0, len, pgoff, flags);
306 /*
307 * Restore the topdown base:
308 */
309 mm->free_area_cache = mm->mmap_base;
310 mm->cached_hole_size = ~0UL;
311
312 return addr;
313}
314
315/* Try to align mapping such that we align it as much as possible. */
316unsigned long get_fb_unmapped_area(struct file *filp, unsigned long orig_addr, unsigned long len, unsigned long pgoff, unsigned long flags)
317{
318 unsigned long align_goal, addr = -ENOMEM;
319 unsigned long (*get_area)(struct file *, unsigned long,
320 unsigned long, unsigned long, unsigned long);
321
322 get_area = current->mm->get_unmapped_area;
323
324 if (flags & MAP_FIXED) {
325 /* Ok, don't mess with it. */
326 return get_area(NULL, orig_addr, len, pgoff, flags);
327 }
328 flags &= ~MAP_SHARED;
329
330 align_goal = PAGE_SIZE;
331 if (len >= (4UL * 1024 * 1024))
332 align_goal = (4UL * 1024 * 1024);
333 else if (len >= (512UL * 1024))
334 align_goal = (512UL * 1024);
335 else if (len >= (64UL * 1024))
336 align_goal = (64UL * 1024);
337
338 do {
339 addr = get_area(NULL, orig_addr, len + (align_goal - PAGE_SIZE), pgoff, flags);
340 if (!(addr & ~PAGE_MASK)) {
341 addr = (addr + (align_goal - 1UL)) & ~(align_goal - 1UL);
342 break;
343 }
344
345 if (align_goal == (4UL * 1024 * 1024))
346 align_goal = (512UL * 1024);
347 else if (align_goal == (512UL * 1024))
348 align_goal = (64UL * 1024);
349 else
350 align_goal = PAGE_SIZE;
351 } while ((addr & ~PAGE_MASK) && align_goal > PAGE_SIZE);
352
353 /* Mapping is smaller than 64K or larger areas could not
354 * be obtained.
355 */
356 if (addr & ~PAGE_MASK)
357 addr = get_area(NULL, orig_addr, len, pgoff, flags);
358
359 return addr;
360}
361EXPORT_SYMBOL(get_fb_unmapped_area);
362
363/* Essentially the same as PowerPC. */
364static unsigned long mmap_rnd(void)
365{
366 unsigned long rnd = 0UL;
367
368 if (current->flags & PF_RANDOMIZE) {
369 unsigned long val = get_random_int();
370 if (test_thread_flag(TIF_32BIT))
371 rnd = (val % (1UL << (23UL-PAGE_SHIFT)));
372 else
373 rnd = (val % (1UL << (30UL-PAGE_SHIFT)));
374 }
375 return rnd << PAGE_SHIFT;
376}
377
378void arch_pick_mmap_layout(struct mm_struct *mm)
379{
380 unsigned long random_factor = mmap_rnd();
381 unsigned long gap;
382
383 /*
384 * Fall back to the standard layout if the personality
385 * bit is set, or if the expected stack growth is unlimited:
386 */
387 gap = rlimit(RLIMIT_STACK);
388 if (!test_thread_flag(TIF_32BIT) ||
389 (current->personality & ADDR_COMPAT_LAYOUT) ||
390 gap == RLIM_INFINITY ||
391 sysctl_legacy_va_layout) {
392 mm->mmap_base = TASK_UNMAPPED_BASE + random_factor;
393 mm->get_unmapped_area = arch_get_unmapped_area;
394 mm->unmap_area = arch_unmap_area;
395 } else {
396 /* We know it's 32-bit */
397 unsigned long task_size = STACK_TOP32;
398
399 if (gap < 128 * 1024 * 1024)
400 gap = 128 * 1024 * 1024;
401 if (gap > (task_size / 6 * 5))
402 gap = (task_size / 6 * 5);
403
404 mm->mmap_base = PAGE_ALIGN(task_size - gap - random_factor);
405 mm->get_unmapped_area = arch_get_unmapped_area_topdown;
406 mm->unmap_area = arch_unmap_area_topdown;
407 }
408}
409
410/*
411 * sys_pipe() is the normal C calling standard for creating
412 * a pipe. It's not the way unix traditionally does this, though.
413 */
414SYSCALL_DEFINE1(sparc_pipe_real, struct pt_regs *, regs)
415{
416 int fd[2];
417 int error;
418
419 error = do_pipe_flags(fd, 0);
420 if (error)
421 goto out;
422 regs->u_regs[UREG_I1] = fd[1];
423 error = fd[0];
424out:
425 return error;
426}
427
428/*
429 * sys_ipc() is the de-multiplexer for the SysV IPC calls..
430 *
431 * This is really horribly ugly.
432 */
433
434SYSCALL_DEFINE6(sparc_ipc, unsigned int, call, int, first, unsigned long, second,
435 unsigned long, third, void __user *, ptr, long, fifth)
436{
437 long err;
438
439 /* No need for backward compatibility. We can start fresh... */
440 if (call <= SEMCTL) {
441 switch (call) {
442 case SEMOP:
443 err = sys_semtimedop(first, ptr,
444 (unsigned)second, NULL);
445 goto out;
446 case SEMTIMEDOP:
447 err = sys_semtimedop(first, ptr, (unsigned)second,
448 (const struct timespec __user *)
449 (unsigned long) fifth);
450 goto out;
451 case SEMGET:
452 err = sys_semget(first, (int)second, (int)third);
453 goto out;
454 case SEMCTL: {
455 err = sys_semctl(first, second,
456 (int)third | IPC_64,
457 (union semun) ptr);
458 goto out;
459 }
460 default:
461 err = -ENOSYS;
462 goto out;
463 }
464 }
465 if (call <= MSGCTL) {
466 switch (call) {
467 case MSGSND:
468 err = sys_msgsnd(first, ptr, (size_t)second,
469 (int)third);
470 goto out;
471 case MSGRCV:
472 err = sys_msgrcv(first, ptr, (size_t)second, fifth,
473 (int)third);
474 goto out;
475 case MSGGET:
476 err = sys_msgget((key_t)first, (int)second);
477 goto out;
478 case MSGCTL:
479 err = sys_msgctl(first, (int)second | IPC_64, ptr);
480 goto out;
481 default:
482 err = -ENOSYS;
483 goto out;
484 }
485 }
486 if (call <= SHMCTL) {
487 switch (call) {
488 case SHMAT: {
489 ulong raddr;
490 err = do_shmat(first, ptr, (int)second, &raddr);
491 if (!err) {
492 if (put_user(raddr,
493 (ulong __user *) third))
494 err = -EFAULT;
495 }
496 goto out;
497 }
498 case SHMDT:
499 err = sys_shmdt(ptr);
500 goto out;
501 case SHMGET:
502 err = sys_shmget(first, (size_t)second, (int)third);
503 goto out;
504 case SHMCTL:
505 err = sys_shmctl(first, (int)second | IPC_64, ptr);
506 goto out;
507 default:
508 err = -ENOSYS;
509 goto out;
510 }
511 } else {
512 err = -ENOSYS;
513 }
514out:
515 return err;
516}
517
518SYSCALL_DEFINE1(sparc64_personality, unsigned long, personality)
519{
520 int ret;
521
522 if (current->personality == PER_LINUX32 &&
523 personality == PER_LINUX)
524 personality = PER_LINUX32;
525 ret = sys_personality(personality);
526 if (ret == PER_LINUX32)
527 ret = PER_LINUX;
528
529 return ret;
530}
531
532int sparc_mmap_check(unsigned long addr, unsigned long len)
533{
534 if (test_thread_flag(TIF_32BIT)) {
535 if (len >= STACK_TOP32)
536 return -EINVAL;
537
538 if (addr > STACK_TOP32 - len)
539 return -EINVAL;
540 } else {
541 if (len >= VA_EXCLUDE_START)
542 return -EINVAL;
543
544 if (invalid_64bit_range(addr, len))
545 return -EINVAL;
546 }
547
548 return 0;
549}
550
551/* Linux version of mmap */
552SYSCALL_DEFINE6(mmap, unsigned long, addr, unsigned long, len,
553 unsigned long, prot, unsigned long, flags, unsigned long, fd,
554 unsigned long, off)
555{
556 unsigned long retval = -EINVAL;
557
558 if ((off + PAGE_ALIGN(len)) < off)
559 goto out;
560 if (off & ~PAGE_MASK)
561 goto out;
562 retval = sys_mmap_pgoff(addr, len, prot, flags, fd, off >> PAGE_SHIFT);
563out:
564 return retval;
565}
566
567SYSCALL_DEFINE2(64_munmap, unsigned long, addr, size_t, len)
568{
569 if (invalid_64bit_range(addr, len))
570 return -EINVAL;
571
572 return vm_munmap(addr, len);
573}
574
575extern unsigned long do_mremap(unsigned long addr,
576 unsigned long old_len, unsigned long new_len,
577 unsigned long flags, unsigned long new_addr);
578
579SYSCALL_DEFINE5(64_mremap, unsigned long, addr, unsigned long, old_len,
580 unsigned long, new_len, unsigned long, flags,
581 unsigned long, new_addr)
582{
583 if (test_thread_flag(TIF_32BIT))
584 return -EINVAL;
585 return sys_mremap(addr, old_len, new_len, flags, new_addr);
586}
587
588/* we come to here via sys_nis_syscall so it can setup the regs argument */
589asmlinkage unsigned long c_sys_nis_syscall(struct pt_regs *regs)
590{
591 static int count;
592
593 /* Don't make the system unusable, if someone goes stuck */
594 if (count++ > 5)
595 return -ENOSYS;
596
597 printk ("Unimplemented SPARC system call %ld\n",regs->u_regs[1]);
598#ifdef DEBUG_UNIMP_SYSCALL
599 show_regs (regs);
600#endif
601
602 return -ENOSYS;
603}
604
605/* #define DEBUG_SPARC_BREAKPOINT */
606
607asmlinkage void sparc_breakpoint(struct pt_regs *regs)
608{
609 siginfo_t info;
610
611 if (test_thread_flag(TIF_32BIT)) {
612 regs->tpc &= 0xffffffff;
613 regs->tnpc &= 0xffffffff;
614 }
615#ifdef DEBUG_SPARC_BREAKPOINT
616 printk ("TRAP: Entering kernel PC=%lx, nPC=%lx\n", regs->tpc, regs->tnpc);
617#endif
618 info.si_signo = SIGTRAP;
619 info.si_errno = 0;
620 info.si_code = TRAP_BRKPT;
621 info.si_addr = (void __user *)regs->tpc;
622 info.si_trapno = 0;
623 force_sig_info(SIGTRAP, &info, current);
624#ifdef DEBUG_SPARC_BREAKPOINT
625 printk ("TRAP: Returning to space: PC=%lx nPC=%lx\n", regs->tpc, regs->tnpc);
626#endif
627}
628
629extern void check_pending(int signum);
630
631SYSCALL_DEFINE2(getdomainname, char __user *, name, int, len)
632{
633 int nlen, err;
634
635 if (len < 0)
636 return -EINVAL;
637
638 down_read(&uts_sem);
639
640 nlen = strlen(utsname()->domainname) + 1;
641 err = -EINVAL;
642 if (nlen > len)
643 goto out;
644
645 err = -EFAULT;
646 if (!copy_to_user(name, utsname()->domainname, nlen))
647 err = 0;
648
649out:
650 up_read(&uts_sem);
651 return err;
652}
653
654SYSCALL_DEFINE5(utrap_install, utrap_entry_t, type,
655 utrap_handler_t, new_p, utrap_handler_t, new_d,
656 utrap_handler_t __user *, old_p,
657 utrap_handler_t __user *, old_d)
658{
659 if (type < UT_INSTRUCTION_EXCEPTION || type > UT_TRAP_INSTRUCTION_31)
660 return -EINVAL;
661 if (new_p == (utrap_handler_t)(long)UTH_NOCHANGE) {
662 if (old_p) {
663 if (!current_thread_info()->utraps) {
664 if (put_user(NULL, old_p))
665 return -EFAULT;
666 } else {
667 if (put_user((utrap_handler_t)(current_thread_info()->utraps[type]), old_p))
668 return -EFAULT;
669 }
670 }
671 if (old_d) {
672 if (put_user(NULL, old_d))
673 return -EFAULT;
674 }
675 return 0;
676 }
677 if (!current_thread_info()->utraps) {
678 current_thread_info()->utraps =
679 kzalloc((UT_TRAP_INSTRUCTION_31+1)*sizeof(long), GFP_KERNEL);
680 if (!current_thread_info()->utraps)
681 return -ENOMEM;
682 current_thread_info()->utraps[0] = 1;
683 } else {
684 if ((utrap_handler_t)current_thread_info()->utraps[type] != new_p &&
685 current_thread_info()->utraps[0] > 1) {
686 unsigned long *p = current_thread_info()->utraps;
687
688 current_thread_info()->utraps =
689 kmalloc((UT_TRAP_INSTRUCTION_31+1)*sizeof(long),
690 GFP_KERNEL);
691 if (!current_thread_info()->utraps) {
692 current_thread_info()->utraps = p;
693 return -ENOMEM;
694 }
695 p[0]--;
696 current_thread_info()->utraps[0] = 1;
697 memcpy(current_thread_info()->utraps+1, p+1,
698 UT_TRAP_INSTRUCTION_31*sizeof(long));
699 }
700 }
701 if (old_p) {
702 if (put_user((utrap_handler_t)(current_thread_info()->utraps[type]), old_p))
703 return -EFAULT;
704 }
705 if (old_d) {
706 if (put_user(NULL, old_d))
707 return -EFAULT;
708 }
709 current_thread_info()->utraps[type] = (long)new_p;
710
711 return 0;
712}
713
714asmlinkage long sparc_memory_ordering(unsigned long model,
715 struct pt_regs *regs)
716{
717 if (model >= 3)
718 return -EINVAL;
719 regs->tstate = (regs->tstate & ~TSTATE_MM) | (model << 14);
720 return 0;
721}
722
723SYSCALL_DEFINE5(rt_sigaction, int, sig, const struct sigaction __user *, act,
724 struct sigaction __user *, oact, void __user *, restorer,
725 size_t, sigsetsize)
726{
727 struct k_sigaction new_ka, old_ka;
728 int ret;
729
730 /* XXX: Don't preclude handling different sized sigset_t's. */
731 if (sigsetsize != sizeof(sigset_t))
732 return -EINVAL;
733
734 if (act) {
735 new_ka.ka_restorer = restorer;
736 if (copy_from_user(&new_ka.sa, act, sizeof(*act)))
737 return -EFAULT;
738 }
739
740 ret = do_sigaction(sig, act ? &new_ka : NULL, oact ? &old_ka : NULL);
741
742 if (!ret && oact) {
743 if (copy_to_user(oact, &old_ka.sa, sizeof(*oact)))
744 return -EFAULT;
745 }
746
747 return ret;
748}
749
750/*
751 * Do a system call from kernel instead of calling sys_execve so we
752 * end up with proper pt_regs.
753 */
754int kernel_execve(const char *filename,
755 const char *const argv[],
756 const char *const envp[])
757{
758 long __res;
759 register long __g1 __asm__ ("g1") = __NR_execve;
760 register long __o0 __asm__ ("o0") = (long)(filename);
761 register long __o1 __asm__ ("o1") = (long)(argv);
762 register long __o2 __asm__ ("o2") = (long)(envp);
763 asm volatile ("t 0x6d\n\t"
764 "sub %%g0, %%o0, %0\n\t"
765 "movcc %%xcc, %%o0, %0\n\t"
766 : "=r" (__res), "=&r" (__o0)
767 : "1" (__o0), "r" (__o1), "r" (__o2), "r" (__g1)
768 : "cc");
769 return __res;
770}
1// SPDX-License-Identifier: GPL-2.0
2/* linux/arch/sparc64/kernel/sys_sparc.c
3 *
4 * This file contains various random system calls that
5 * have a non-standard calling sequence on the Linux/sparc
6 * platform.
7 */
8
9#include <linux/errno.h>
10#include <linux/types.h>
11#include <linux/sched/signal.h>
12#include <linux/sched/mm.h>
13#include <linux/sched/debug.h>
14#include <linux/fs.h>
15#include <linux/file.h>
16#include <linux/mm.h>
17#include <linux/sem.h>
18#include <linux/msg.h>
19#include <linux/shm.h>
20#include <linux/stat.h>
21#include <linux/mman.h>
22#include <linux/utsname.h>
23#include <linux/smp.h>
24#include <linux/slab.h>
25#include <linux/syscalls.h>
26#include <linux/ipc.h>
27#include <linux/personality.h>
28#include <linux/random.h>
29#include <linux/export.h>
30#include <linux/context_tracking.h>
31#include <linux/timex.h>
32#include <linux/uaccess.h>
33
34#include <asm/utrap.h>
35#include <asm/unistd.h>
36
37#include "entry.h"
38#include "kernel.h"
39#include "systbls.h"
40
41/* #define DEBUG_UNIMP_SYSCALL */
42
43SYSCALL_DEFINE0(getpagesize)
44{
45 return PAGE_SIZE;
46}
47
48/* Does addr --> addr+len fall within 4GB of the VA-space hole or
49 * overflow past the end of the 64-bit address space?
50 */
51static inline int invalid_64bit_range(unsigned long addr, unsigned long len)
52{
53 unsigned long va_exclude_start, va_exclude_end;
54
55 va_exclude_start = VA_EXCLUDE_START;
56 va_exclude_end = VA_EXCLUDE_END;
57
58 if (unlikely(len >= va_exclude_start))
59 return 1;
60
61 if (unlikely((addr + len) < addr))
62 return 1;
63
64 if (unlikely((addr >= va_exclude_start && addr < va_exclude_end) ||
65 ((addr + len) >= va_exclude_start &&
66 (addr + len) < va_exclude_end)))
67 return 1;
68
69 return 0;
70}
71
72/* These functions differ from the default implementations in
73 * mm/mmap.c in two ways:
74 *
75 * 1) For file backed MAP_SHARED mmap()'s we D-cache color align,
76 * for fixed such mappings we just validate what the user gave us.
77 * 2) For 64-bit tasks we avoid mapping anything within 4GB of
78 * the spitfire/niagara VA-hole.
79 */
80
81static inline unsigned long COLOR_ALIGN(unsigned long addr,
82 unsigned long pgoff)
83{
84 unsigned long base = (addr+SHMLBA-1)&~(SHMLBA-1);
85 unsigned long off = (pgoff<<PAGE_SHIFT) & (SHMLBA-1);
86
87 return base + off;
88}
89
90unsigned long arch_get_unmapped_area(struct file *filp, unsigned long addr, unsigned long len, unsigned long pgoff, unsigned long flags)
91{
92 struct mm_struct *mm = current->mm;
93 struct vm_area_struct * vma;
94 unsigned long task_size = TASK_SIZE;
95 int do_color_align;
96 struct vm_unmapped_area_info info;
97
98 if (flags & MAP_FIXED) {
99 /* We do not accept a shared mapping if it would violate
100 * cache aliasing constraints.
101 */
102 if ((flags & MAP_SHARED) &&
103 ((addr - (pgoff << PAGE_SHIFT)) & (SHMLBA - 1)))
104 return -EINVAL;
105 return addr;
106 }
107
108 if (test_thread_flag(TIF_32BIT))
109 task_size = STACK_TOP32;
110 if (unlikely(len > task_size || len >= VA_EXCLUDE_START))
111 return -ENOMEM;
112
113 do_color_align = 0;
114 if (filp || (flags & MAP_SHARED))
115 do_color_align = 1;
116
117 if (addr) {
118 if (do_color_align)
119 addr = COLOR_ALIGN(addr, pgoff);
120 else
121 addr = PAGE_ALIGN(addr);
122
123 vma = find_vma(mm, addr);
124 if (task_size - len >= addr &&
125 (!vma || addr + len <= vm_start_gap(vma)))
126 return addr;
127 }
128
129 info.flags = 0;
130 info.length = len;
131 info.low_limit = TASK_UNMAPPED_BASE;
132 info.high_limit = min(task_size, VA_EXCLUDE_START);
133 info.align_mask = do_color_align ? (PAGE_MASK & (SHMLBA - 1)) : 0;
134 info.align_offset = pgoff << PAGE_SHIFT;
135 addr = vm_unmapped_area(&info);
136
137 if ((addr & ~PAGE_MASK) && task_size > VA_EXCLUDE_END) {
138 VM_BUG_ON(addr != -ENOMEM);
139 info.low_limit = VA_EXCLUDE_END;
140 info.high_limit = task_size;
141 addr = vm_unmapped_area(&info);
142 }
143
144 return addr;
145}
146
147unsigned long
148arch_get_unmapped_area_topdown(struct file *filp, const unsigned long addr0,
149 const unsigned long len, const unsigned long pgoff,
150 const unsigned long flags)
151{
152 struct vm_area_struct *vma;
153 struct mm_struct *mm = current->mm;
154 unsigned long task_size = STACK_TOP32;
155 unsigned long addr = addr0;
156 int do_color_align;
157 struct vm_unmapped_area_info info;
158
159 /* This should only ever run for 32-bit processes. */
160 BUG_ON(!test_thread_flag(TIF_32BIT));
161
162 if (flags & MAP_FIXED) {
163 /* We do not accept a shared mapping if it would violate
164 * cache aliasing constraints.
165 */
166 if ((flags & MAP_SHARED) &&
167 ((addr - (pgoff << PAGE_SHIFT)) & (SHMLBA - 1)))
168 return -EINVAL;
169 return addr;
170 }
171
172 if (unlikely(len > task_size))
173 return -ENOMEM;
174
175 do_color_align = 0;
176 if (filp || (flags & MAP_SHARED))
177 do_color_align = 1;
178
179 /* requesting a specific address */
180 if (addr) {
181 if (do_color_align)
182 addr = COLOR_ALIGN(addr, pgoff);
183 else
184 addr = PAGE_ALIGN(addr);
185
186 vma = find_vma(mm, addr);
187 if (task_size - len >= addr &&
188 (!vma || addr + len <= vm_start_gap(vma)))
189 return addr;
190 }
191
192 info.flags = VM_UNMAPPED_AREA_TOPDOWN;
193 info.length = len;
194 info.low_limit = PAGE_SIZE;
195 info.high_limit = mm->mmap_base;
196 info.align_mask = do_color_align ? (PAGE_MASK & (SHMLBA - 1)) : 0;
197 info.align_offset = pgoff << PAGE_SHIFT;
198 addr = vm_unmapped_area(&info);
199
200 /*
201 * A failed mmap() very likely causes application failure,
202 * so fall back to the bottom-up function here. This scenario
203 * can happen with large stack limits and large mmap()
204 * allocations.
205 */
206 if (addr & ~PAGE_MASK) {
207 VM_BUG_ON(addr != -ENOMEM);
208 info.flags = 0;
209 info.low_limit = TASK_UNMAPPED_BASE;
210 info.high_limit = STACK_TOP32;
211 addr = vm_unmapped_area(&info);
212 }
213
214 return addr;
215}
216
217/* Try to align mapping such that we align it as much as possible. */
218unsigned long get_fb_unmapped_area(struct file *filp, unsigned long orig_addr, unsigned long len, unsigned long pgoff, unsigned long flags)
219{
220 unsigned long align_goal, addr = -ENOMEM;
221 unsigned long (*get_area)(struct file *, unsigned long,
222 unsigned long, unsigned long, unsigned long);
223
224 get_area = current->mm->get_unmapped_area;
225
226 if (flags & MAP_FIXED) {
227 /* Ok, don't mess with it. */
228 return get_area(NULL, orig_addr, len, pgoff, flags);
229 }
230 flags &= ~MAP_SHARED;
231
232 align_goal = PAGE_SIZE;
233 if (len >= (4UL * 1024 * 1024))
234 align_goal = (4UL * 1024 * 1024);
235 else if (len >= (512UL * 1024))
236 align_goal = (512UL * 1024);
237 else if (len >= (64UL * 1024))
238 align_goal = (64UL * 1024);
239
240 do {
241 addr = get_area(NULL, orig_addr, len + (align_goal - PAGE_SIZE), pgoff, flags);
242 if (!(addr & ~PAGE_MASK)) {
243 addr = (addr + (align_goal - 1UL)) & ~(align_goal - 1UL);
244 break;
245 }
246
247 if (align_goal == (4UL * 1024 * 1024))
248 align_goal = (512UL * 1024);
249 else if (align_goal == (512UL * 1024))
250 align_goal = (64UL * 1024);
251 else
252 align_goal = PAGE_SIZE;
253 } while ((addr & ~PAGE_MASK) && align_goal > PAGE_SIZE);
254
255 /* Mapping is smaller than 64K or larger areas could not
256 * be obtained.
257 */
258 if (addr & ~PAGE_MASK)
259 addr = get_area(NULL, orig_addr, len, pgoff, flags);
260
261 return addr;
262}
263EXPORT_SYMBOL(get_fb_unmapped_area);
264
265/* Essentially the same as PowerPC. */
266static unsigned long mmap_rnd(void)
267{
268 unsigned long rnd = 0UL;
269
270 if (current->flags & PF_RANDOMIZE) {
271 unsigned long val = get_random_long();
272 if (test_thread_flag(TIF_32BIT))
273 rnd = (val % (1UL << (23UL-PAGE_SHIFT)));
274 else
275 rnd = (val % (1UL << (30UL-PAGE_SHIFT)));
276 }
277 return rnd << PAGE_SHIFT;
278}
279
280void arch_pick_mmap_layout(struct mm_struct *mm, struct rlimit *rlim_stack)
281{
282 unsigned long random_factor = mmap_rnd();
283 unsigned long gap;
284
285 /*
286 * Fall back to the standard layout if the personality
287 * bit is set, or if the expected stack growth is unlimited:
288 */
289 gap = rlim_stack->rlim_cur;
290 if (!test_thread_flag(TIF_32BIT) ||
291 (current->personality & ADDR_COMPAT_LAYOUT) ||
292 gap == RLIM_INFINITY ||
293 sysctl_legacy_va_layout) {
294 mm->mmap_base = TASK_UNMAPPED_BASE + random_factor;
295 mm->get_unmapped_area = arch_get_unmapped_area;
296 } else {
297 /* We know it's 32-bit */
298 unsigned long task_size = STACK_TOP32;
299
300 if (gap < 128 * 1024 * 1024)
301 gap = 128 * 1024 * 1024;
302 if (gap > (task_size / 6 * 5))
303 gap = (task_size / 6 * 5);
304
305 mm->mmap_base = PAGE_ALIGN(task_size - gap - random_factor);
306 mm->get_unmapped_area = arch_get_unmapped_area_topdown;
307 }
308}
309
310/*
311 * sys_pipe() is the normal C calling standard for creating
312 * a pipe. It's not the way unix traditionally does this, though.
313 */
314SYSCALL_DEFINE0(sparc_pipe)
315{
316 int fd[2];
317 int error;
318
319 error = do_pipe_flags(fd, 0);
320 if (error)
321 goto out;
322 current_pt_regs()->u_regs[UREG_I1] = fd[1];
323 error = fd[0];
324out:
325 return error;
326}
327
328/*
329 * sys_ipc() is the de-multiplexer for the SysV IPC calls..
330 *
331 * This is really horribly ugly.
332 */
333
334SYSCALL_DEFINE6(sparc_ipc, unsigned int, call, int, first, unsigned long, second,
335 unsigned long, third, void __user *, ptr, long, fifth)
336{
337 long err;
338
339 if (!IS_ENABLED(CONFIG_SYSVIPC))
340 return -ENOSYS;
341
342 /* No need for backward compatibility. We can start fresh... */
343 if (call <= SEMTIMEDOP) {
344 switch (call) {
345 case SEMOP:
346 err = ksys_semtimedop(first, ptr,
347 (unsigned int)second, NULL);
348 goto out;
349 case SEMTIMEDOP:
350 err = ksys_semtimedop(first, ptr, (unsigned int)second,
351 (const struct __kernel_timespec __user *)
352 (unsigned long) fifth);
353 goto out;
354 case SEMGET:
355 err = ksys_semget(first, (int)second, (int)third);
356 goto out;
357 case SEMCTL: {
358 err = ksys_old_semctl(first, second,
359 (int)third | IPC_64,
360 (unsigned long) ptr);
361 goto out;
362 }
363 default:
364 err = -ENOSYS;
365 goto out;
366 }
367 }
368 if (call <= MSGCTL) {
369 switch (call) {
370 case MSGSND:
371 err = ksys_msgsnd(first, ptr, (size_t)second,
372 (int)third);
373 goto out;
374 case MSGRCV:
375 err = ksys_msgrcv(first, ptr, (size_t)second, fifth,
376 (int)third);
377 goto out;
378 case MSGGET:
379 err = ksys_msgget((key_t)first, (int)second);
380 goto out;
381 case MSGCTL:
382 err = ksys_old_msgctl(first, (int)second | IPC_64, ptr);
383 goto out;
384 default:
385 err = -ENOSYS;
386 goto out;
387 }
388 }
389 if (call <= SHMCTL) {
390 switch (call) {
391 case SHMAT: {
392 ulong raddr;
393 err = do_shmat(first, ptr, (int)second, &raddr, SHMLBA);
394 if (!err) {
395 if (put_user(raddr,
396 (ulong __user *) third))
397 err = -EFAULT;
398 }
399 goto out;
400 }
401 case SHMDT:
402 err = ksys_shmdt(ptr);
403 goto out;
404 case SHMGET:
405 err = ksys_shmget(first, (size_t)second, (int)third);
406 goto out;
407 case SHMCTL:
408 err = ksys_old_shmctl(first, (int)second | IPC_64, ptr);
409 goto out;
410 default:
411 err = -ENOSYS;
412 goto out;
413 }
414 } else {
415 err = -ENOSYS;
416 }
417out:
418 return err;
419}
420
421SYSCALL_DEFINE1(sparc64_personality, unsigned long, personality)
422{
423 long ret;
424
425 if (personality(current->personality) == PER_LINUX32 &&
426 personality(personality) == PER_LINUX)
427 personality |= PER_LINUX32;
428 ret = sys_personality(personality);
429 if (personality(ret) == PER_LINUX32)
430 ret &= ~PER_LINUX32;
431
432 return ret;
433}
434
435int sparc_mmap_check(unsigned long addr, unsigned long len)
436{
437 if (test_thread_flag(TIF_32BIT)) {
438 if (len >= STACK_TOP32)
439 return -EINVAL;
440
441 if (addr > STACK_TOP32 - len)
442 return -EINVAL;
443 } else {
444 if (len >= VA_EXCLUDE_START)
445 return -EINVAL;
446
447 if (invalid_64bit_range(addr, len))
448 return -EINVAL;
449 }
450
451 return 0;
452}
453
454/* Linux version of mmap */
455SYSCALL_DEFINE6(mmap, unsigned long, addr, unsigned long, len,
456 unsigned long, prot, unsigned long, flags, unsigned long, fd,
457 unsigned long, off)
458{
459 unsigned long retval = -EINVAL;
460
461 if ((off + PAGE_ALIGN(len)) < off)
462 goto out;
463 if (off & ~PAGE_MASK)
464 goto out;
465 retval = ksys_mmap_pgoff(addr, len, prot, flags, fd, off >> PAGE_SHIFT);
466out:
467 return retval;
468}
469
470SYSCALL_DEFINE2(64_munmap, unsigned long, addr, size_t, len)
471{
472 if (invalid_64bit_range(addr, len))
473 return -EINVAL;
474
475 return vm_munmap(addr, len);
476}
477
478SYSCALL_DEFINE5(64_mremap, unsigned long, addr, unsigned long, old_len,
479 unsigned long, new_len, unsigned long, flags,
480 unsigned long, new_addr)
481{
482 if (test_thread_flag(TIF_32BIT))
483 return -EINVAL;
484 return sys_mremap(addr, old_len, new_len, flags, new_addr);
485}
486
487SYSCALL_DEFINE0(nis_syscall)
488{
489 static int count;
490 struct pt_regs *regs = current_pt_regs();
491
492 /* Don't make the system unusable, if someone goes stuck */
493 if (count++ > 5)
494 return -ENOSYS;
495
496 printk ("Unimplemented SPARC system call %ld\n",regs->u_regs[1]);
497#ifdef DEBUG_UNIMP_SYSCALL
498 show_regs (regs);
499#endif
500
501 return -ENOSYS;
502}
503
504/* #define DEBUG_SPARC_BREAKPOINT */
505
506asmlinkage void sparc_breakpoint(struct pt_regs *regs)
507{
508 enum ctx_state prev_state = exception_enter();
509
510 if (test_thread_flag(TIF_32BIT)) {
511 regs->tpc &= 0xffffffff;
512 regs->tnpc &= 0xffffffff;
513 }
514#ifdef DEBUG_SPARC_BREAKPOINT
515 printk ("TRAP: Entering kernel PC=%lx, nPC=%lx\n", regs->tpc, regs->tnpc);
516#endif
517 force_sig_fault(SIGTRAP, TRAP_BRKPT, (void __user *)regs->tpc, 0);
518#ifdef DEBUG_SPARC_BREAKPOINT
519 printk ("TRAP: Returning to space: PC=%lx nPC=%lx\n", regs->tpc, regs->tnpc);
520#endif
521 exception_exit(prev_state);
522}
523
524SYSCALL_DEFINE2(getdomainname, char __user *, name, int, len)
525{
526 int nlen, err;
527 char tmp[__NEW_UTS_LEN + 1];
528
529 if (len < 0)
530 return -EINVAL;
531
532 down_read(&uts_sem);
533
534 nlen = strlen(utsname()->domainname) + 1;
535 err = -EINVAL;
536 if (nlen > len)
537 goto out_unlock;
538 memcpy(tmp, utsname()->domainname, nlen);
539
540 up_read(&uts_sem);
541
542 if (copy_to_user(name, tmp, nlen))
543 return -EFAULT;
544 return 0;
545
546out_unlock:
547 up_read(&uts_sem);
548 return err;
549}
550
551SYSCALL_DEFINE1(sparc_adjtimex, struct timex __user *, txc_p)
552{
553 struct timex txc; /* Local copy of parameter */
554 struct __kernel_timex *kt = (void *)&txc;
555 int ret;
556
557 /* Copy the user data space into the kernel copy
558 * structure. But bear in mind that the structures
559 * may change
560 */
561 if (copy_from_user(&txc, txc_p, sizeof(struct timex)))
562 return -EFAULT;
563
564 /*
565 * override for sparc64 specific timeval type: tv_usec
566 * is 32 bit wide instead of 64-bit in __kernel_timex
567 */
568 kt->time.tv_usec = txc.time.tv_usec;
569 ret = do_adjtimex(kt);
570 txc.time.tv_usec = kt->time.tv_usec;
571
572 return copy_to_user(txc_p, &txc, sizeof(struct timex)) ? -EFAULT : ret;
573}
574
575SYSCALL_DEFINE2(sparc_clock_adjtime, const clockid_t, which_clock,struct timex __user *, txc_p)
576{
577 struct timex txc; /* Local copy of parameter */
578 struct __kernel_timex *kt = (void *)&txc;
579 int ret;
580
581 if (!IS_ENABLED(CONFIG_POSIX_TIMERS)) {
582 pr_err_once("process %d (%s) attempted a POSIX timer syscall "
583 "while CONFIG_POSIX_TIMERS is not set\n",
584 current->pid, current->comm);
585
586 return -ENOSYS;
587 }
588
589 /* Copy the user data space into the kernel copy
590 * structure. But bear in mind that the structures
591 * may change
592 */
593 if (copy_from_user(&txc, txc_p, sizeof(struct timex)))
594 return -EFAULT;
595
596 /*
597 * override for sparc64 specific timeval type: tv_usec
598 * is 32 bit wide instead of 64-bit in __kernel_timex
599 */
600 kt->time.tv_usec = txc.time.tv_usec;
601 ret = do_clock_adjtime(which_clock, kt);
602 txc.time.tv_usec = kt->time.tv_usec;
603
604 return copy_to_user(txc_p, &txc, sizeof(struct timex)) ? -EFAULT : ret;
605}
606
607SYSCALL_DEFINE5(utrap_install, utrap_entry_t, type,
608 utrap_handler_t, new_p, utrap_handler_t, new_d,
609 utrap_handler_t __user *, old_p,
610 utrap_handler_t __user *, old_d)
611{
612 if (type < UT_INSTRUCTION_EXCEPTION || type > UT_TRAP_INSTRUCTION_31)
613 return -EINVAL;
614 if (new_p == (utrap_handler_t)(long)UTH_NOCHANGE) {
615 if (old_p) {
616 if (!current_thread_info()->utraps) {
617 if (put_user(NULL, old_p))
618 return -EFAULT;
619 } else {
620 if (put_user((utrap_handler_t)(current_thread_info()->utraps[type]), old_p))
621 return -EFAULT;
622 }
623 }
624 if (old_d) {
625 if (put_user(NULL, old_d))
626 return -EFAULT;
627 }
628 return 0;
629 }
630 if (!current_thread_info()->utraps) {
631 current_thread_info()->utraps =
632 kcalloc(UT_TRAP_INSTRUCTION_31 + 1, sizeof(long),
633 GFP_KERNEL);
634 if (!current_thread_info()->utraps)
635 return -ENOMEM;
636 current_thread_info()->utraps[0] = 1;
637 } else {
638 if ((utrap_handler_t)current_thread_info()->utraps[type] != new_p &&
639 current_thread_info()->utraps[0] > 1) {
640 unsigned long *p = current_thread_info()->utraps;
641
642 current_thread_info()->utraps =
643 kmalloc_array(UT_TRAP_INSTRUCTION_31 + 1,
644 sizeof(long),
645 GFP_KERNEL);
646 if (!current_thread_info()->utraps) {
647 current_thread_info()->utraps = p;
648 return -ENOMEM;
649 }
650 p[0]--;
651 current_thread_info()->utraps[0] = 1;
652 memcpy(current_thread_info()->utraps+1, p+1,
653 UT_TRAP_INSTRUCTION_31*sizeof(long));
654 }
655 }
656 if (old_p) {
657 if (put_user((utrap_handler_t)(current_thread_info()->utraps[type]), old_p))
658 return -EFAULT;
659 }
660 if (old_d) {
661 if (put_user(NULL, old_d))
662 return -EFAULT;
663 }
664 current_thread_info()->utraps[type] = (long)new_p;
665
666 return 0;
667}
668
669SYSCALL_DEFINE1(memory_ordering, unsigned long, model)
670{
671 struct pt_regs *regs = current_pt_regs();
672 if (model >= 3)
673 return -EINVAL;
674 regs->tstate = (regs->tstate & ~TSTATE_MM) | (model << 14);
675 return 0;
676}
677
678SYSCALL_DEFINE5(rt_sigaction, int, sig, const struct sigaction __user *, act,
679 struct sigaction __user *, oact, void __user *, restorer,
680 size_t, sigsetsize)
681{
682 struct k_sigaction new_ka, old_ka;
683 int ret;
684
685 /* XXX: Don't preclude handling different sized sigset_t's. */
686 if (sigsetsize != sizeof(sigset_t))
687 return -EINVAL;
688
689 if (act) {
690 new_ka.ka_restorer = restorer;
691 if (copy_from_user(&new_ka.sa, act, sizeof(*act)))
692 return -EFAULT;
693 }
694
695 ret = do_sigaction(sig, act ? &new_ka : NULL, oact ? &old_ka : NULL);
696
697 if (!ret && oact) {
698 if (copy_to_user(oact, &old_ka.sa, sizeof(*oact)))
699 return -EFAULT;
700 }
701
702 return ret;
703}
704
705SYSCALL_DEFINE0(kern_features)
706{
707 return KERN_FEATURE_MIXED_MODE_STACK;
708}