blob: c399e7b3b035250d66ed4522d2da190dc6169aa3 [file] [log] [blame]
Adrian Bunk88278ca2008-05-19 16:53:02 -07001/*
Linus Torvalds1da177e2005-04-16 15:20:36 -07002 * fault.c: Page fault handlers for the Sparc.
3 *
4 * Copyright (C) 1995 David S. Miller (davem@caip.rutgers.edu)
5 * Copyright (C) 1996 Eddie C. Dost (ecd@skynet.be)
6 * Copyright (C) 1997 Jakub Jelinek (jj@sunsite.mff.cuni.cz)
7 */
8
9#include <asm/head.h>
10
11#include <linux/string.h>
12#include <linux/types.h>
13#include <linux/sched.h>
14#include <linux/ptrace.h>
15#include <linux/mman.h>
16#include <linux/threads.h>
17#include <linux/kernel.h>
18#include <linux/signal.h>
19#include <linux/mm.h>
20#include <linux/smp.h>
David S. Millera084b662010-01-20 03:04:14 -080021#include <linux/perf_event.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070022#include <linux/interrupt.h>
Christoph Hellwig1eeb66a2007-05-08 00:27:03 -070023#include <linux/kdebug.h>
David Hildenbrand70ffdb92015-05-11 17:52:11 +020024#include <linux/uaccess.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070025
Linus Torvalds1da177e2005-04-16 15:20:36 -070026#include <asm/page.h>
27#include <asm/pgtable.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070028#include <asm/openprom.h>
29#include <asm/oplib.h>
Sam Ravnborg9edfae32014-04-21 21:39:38 +020030#include <asm/setup.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070031#include <asm/smp.h>
32#include <asm/traps.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070033
Sam Ravnborge1b2f1342014-04-21 21:39:17 +020034#include "mm_32.h"
David S. Miller4b177642010-03-01 00:02:23 -080035
Sam Ravnborge1b2f1342014-04-21 21:39:17 +020036int show_unhandled_signals = 1;
Linus Torvalds1da177e2005-04-16 15:20:36 -070037
Sam Ravnborg70168df2012-05-15 19:02:08 +020038static void __noreturn unhandled_fault(unsigned long address,
39 struct task_struct *tsk,
40 struct pt_regs *regs)
Linus Torvalds1da177e2005-04-16 15:20:36 -070041{
Sam Ravnborg70168df2012-05-15 19:02:08 +020042 if ((unsigned long) address < PAGE_SIZE) {
Linus Torvalds1da177e2005-04-16 15:20:36 -070043 printk(KERN_ALERT
44 "Unable to handle kernel NULL pointer dereference\n");
45 } else {
Sam Ravnborg70168df2012-05-15 19:02:08 +020046 printk(KERN_ALERT "Unable to handle kernel paging request at virtual address %08lx\n",
47 address);
Linus Torvalds1da177e2005-04-16 15:20:36 -070048 }
49 printk(KERN_ALERT "tsk->{mm,active_mm}->context = %08lx\n",
50 (tsk->mm ? tsk->mm->context : tsk->active_mm->context));
51 printk(KERN_ALERT "tsk->{mm,active_mm}->pgd = %08lx\n",
52 (tsk->mm ? (unsigned long) tsk->mm->pgd :
Sam Ravnborg70168df2012-05-15 19:02:08 +020053 (unsigned long) tsk->active_mm->pgd));
Linus Torvalds1da177e2005-04-16 15:20:36 -070054 die_if_kernel("Oops", regs);
55}
56
Sam Ravnborg70168df2012-05-15 19:02:08 +020057asmlinkage int lookup_fault(unsigned long pc, unsigned long ret_pc,
Linus Torvalds1da177e2005-04-16 15:20:36 -070058 unsigned long address)
59{
60 struct pt_regs regs;
61 unsigned long g2;
62 unsigned int insn;
63 int i;
Sam Ravnborg70168df2012-05-15 19:02:08 +020064
Linus Torvalds1da177e2005-04-16 15:20:36 -070065 i = search_extables_range(ret_pc, &g2);
66 switch (i) {
67 case 3:
68 /* load & store will be handled by fixup */
69 return 3;
70
71 case 1:
72 /* store will be handled by fixup, load will bump out */
73 /* for _to_ macros */
74 insn = *((unsigned int *) pc);
75 if ((insn >> 21) & 1)
76 return 1;
77 break;
78
79 case 2:
80 /* load will be handled by fixup, store will bump out */
81 /* for _from_ macros */
82 insn = *((unsigned int *) pc);
83 if (!((insn >> 21) & 1) || ((insn>>19)&0x3f) == 15)
Sam Ravnborg70168df2012-05-15 19:02:08 +020084 return 2;
85 break;
Linus Torvalds1da177e2005-04-16 15:20:36 -070086
87 default:
88 break;
Joe Perches6cb79b32011-06-03 14:45:23 +000089 }
Linus Torvalds1da177e2005-04-16 15:20:36 -070090
Sam Ravnborg70168df2012-05-15 19:02:08 +020091 memset(&regs, 0, sizeof(regs));
Linus Torvalds1da177e2005-04-16 15:20:36 -070092 regs.pc = pc;
93 regs.npc = pc + 4;
94 __asm__ __volatile__(
95 "rd %%psr, %0\n\t"
96 "nop\n\t"
97 "nop\n\t"
98 "nop\n" : "=r" (regs.psr));
99 unhandled_fault(address, current, &regs);
100
101 /* Not reached */
102 return 0;
103}
104
David S. Miller4b177642010-03-01 00:02:23 -0800105static inline void
106show_signal_msg(struct pt_regs *regs, int sig, int code,
107 unsigned long address, struct task_struct *tsk)
108{
109 if (!unhandled_signal(tsk, sig))
110 return;
111
112 if (!printk_ratelimit())
113 return;
114
115 printk("%s%s[%d]: segfault at %lx ip %p (rpc %p) sp %p error %x",
116 task_pid_nr(tsk) > 1 ? KERN_INFO : KERN_EMERG,
117 tsk->comm, task_pid_nr(tsk), address,
118 (void *)regs->pc, (void *)regs->u_regs[UREG_I7],
119 (void *)regs->u_regs[UREG_FP], code);
120
121 print_vma_addr(KERN_CONT " in ", regs->pc);
122
123 printk(KERN_CONT "\n");
124}
125
126static void __do_fault_siginfo(int code, int sig, struct pt_regs *regs,
127 unsigned long addr)
128{
129 siginfo_t info;
130
131 info.si_signo = sig;
132 info.si_code = code;
133 info.si_errno = 0;
134 info.si_addr = (void __user *) addr;
135 info.si_trapno = 0;
136
137 if (unlikely(show_unhandled_signals))
138 show_signal_msg(regs, sig, info.si_code,
139 addr, current);
140
141 force_sig_info (sig, &info, current);
142}
143
Linus Torvalds1da177e2005-04-16 15:20:36 -0700144static unsigned long compute_si_addr(struct pt_regs *regs, int text_fault)
145{
146 unsigned int insn;
147
148 if (text_fault)
149 return regs->pc;
150
Sam Ravnborg70168df2012-05-15 19:02:08 +0200151 if (regs->psr & PSR_PS)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700152 insn = *(unsigned int *) regs->pc;
Sam Ravnborg70168df2012-05-15 19:02:08 +0200153 else
Linus Torvalds1da177e2005-04-16 15:20:36 -0700154 __get_user(insn, (unsigned int *) regs->pc);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700155
156 return safe_compute_effective_address(regs, insn);
157}
158
David S. Miller4b177642010-03-01 00:02:23 -0800159static noinline void do_fault_siginfo(int code, int sig, struct pt_regs *regs,
160 int text_fault)
161{
162 unsigned long addr = compute_si_addr(regs, text_fault);
163
164 __do_fault_siginfo(code, sig, regs, addr);
165}
166
Linus Torvalds1da177e2005-04-16 15:20:36 -0700167asmlinkage void do_sparc_fault(struct pt_regs *regs, int text_fault, int write,
168 unsigned long address)
169{
170 struct vm_area_struct *vma;
171 struct task_struct *tsk = current;
172 struct mm_struct *mm = tsk->mm;
173 unsigned int fixup;
174 unsigned long g2;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700175 int from_user = !(regs->psr & PSR_PS);
David S. Miller4b177642010-03-01 00:02:23 -0800176 int fault, code;
Johannes Weiner759496b2013-09-12 15:13:39 -0700177 unsigned int flags = FAULT_FLAG_ALLOW_RETRY | FAULT_FLAG_KILLABLE;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700178
Sam Ravnborg70168df2012-05-15 19:02:08 +0200179 if (text_fault)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700180 address = regs->pc;
181
182 /*
183 * We fault-in kernel-space virtual memory on-demand. The
184 * 'reference' page table is init_mm.pgd.
185 *
186 * NOTE! We MUST NOT take any locks for this case. We may
187 * be in an interrupt or a critical region, and should
188 * only copy the information from the master page table,
189 * nothing more.
190 */
David S. Millerc816be72011-03-09 13:00:47 -0800191 code = SEGV_MAPERR;
Sam Ravnborg582a0ba2012-05-11 11:35:08 +0000192 if (address >= TASK_SIZE)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700193 goto vmalloc_fault;
194
Linus Torvalds1da177e2005-04-16 15:20:36 -0700195 /*
196 * If we're in an interrupt or have no user
197 * context, we must not take the fault..
198 */
David Hildenbrand70ffdb92015-05-11 17:52:11 +0200199 if (pagefault_disabled() || !mm)
Sam Ravnborg70168df2012-05-15 19:02:08 +0200200 goto no_context;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700201
Peter Zijlstraa8b0ca12011-06-27 14:41:57 +0200202 perf_sw_event(PERF_COUNT_SW_PAGE_FAULTS, 1, regs, address);
David S. Millera084b662010-01-20 03:04:14 -0800203
Kautuk Consulc29554f2012-03-26 06:47:54 +0000204retry:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700205 down_read(&mm->mmap_sem);
206
Sam Ravnborg70168df2012-05-15 19:02:08 +0200207 if (!from_user && address >= PAGE_OFFSET)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700208 goto bad_area;
209
210 vma = find_vma(mm, address);
Sam Ravnborg70168df2012-05-15 19:02:08 +0200211 if (!vma)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700212 goto bad_area;
Sam Ravnborg70168df2012-05-15 19:02:08 +0200213 if (vma->vm_start <= address)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700214 goto good_area;
Sam Ravnborg70168df2012-05-15 19:02:08 +0200215 if (!(vma->vm_flags & VM_GROWSDOWN))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700216 goto bad_area;
Sam Ravnborg70168df2012-05-15 19:02:08 +0200217 if (expand_stack(vma, address))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700218 goto bad_area;
219 /*
220 * Ok, we have a good vm_area for this memory access, so
221 * we can handle it..
222 */
223good_area:
David S. Miller4b177642010-03-01 00:02:23 -0800224 code = SEGV_ACCERR;
Sam Ravnborg70168df2012-05-15 19:02:08 +0200225 if (write) {
226 if (!(vma->vm_flags & VM_WRITE))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700227 goto bad_area;
228 } else {
229 /* Allow reads even for write-only mappings */
Sam Ravnborg70168df2012-05-15 19:02:08 +0200230 if (!(vma->vm_flags & (VM_READ | VM_EXEC)))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700231 goto bad_area;
232 }
233
Johannes Weiner759496b2013-09-12 15:13:39 -0700234 if (from_user)
235 flags |= FAULT_FLAG_USER;
236 if (write)
237 flags |= FAULT_FLAG_WRITE;
238
Linus Torvalds1da177e2005-04-16 15:20:36 -0700239 /*
240 * If for any reason at all we couldn't handle the fault,
241 * make sure we exit gracefully rather than endlessly redo
242 * the fault.
243 */
Kautuk Consulc29554f2012-03-26 06:47:54 +0000244 fault = handle_mm_fault(mm, vma, address, flags);
245
246 if ((fault & VM_FAULT_RETRY) && fatal_signal_pending(current))
247 return;
248
Nick Piggin83c54072007-07-19 01:47:05 -0700249 if (unlikely(fault & VM_FAULT_ERROR)) {
250 if (fault & VM_FAULT_OOM)
251 goto out_of_memory;
Linus Torvalds33692f22015-01-29 10:51:32 -0800252 else if (fault & VM_FAULT_SIGSEGV)
253 goto bad_area;
Nick Piggin83c54072007-07-19 01:47:05 -0700254 else if (fault & VM_FAULT_SIGBUS)
255 goto do_sigbus;
256 BUG();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700257 }
Kautuk Consulc29554f2012-03-26 06:47:54 +0000258
259 if (flags & FAULT_FLAG_ALLOW_RETRY) {
260 if (fault & VM_FAULT_MAJOR) {
261 current->maj_flt++;
262 perf_sw_event(PERF_COUNT_SW_PAGE_FAULTS_MAJ,
263 1, regs, address);
264 } else {
265 current->min_flt++;
266 perf_sw_event(PERF_COUNT_SW_PAGE_FAULTS_MIN,
267 1, regs, address);
268 }
269 if (fault & VM_FAULT_RETRY) {
270 flags &= ~FAULT_FLAG_ALLOW_RETRY;
Shaohua Li45cac652012-10-08 16:32:19 -0700271 flags |= FAULT_FLAG_TRIED;
Kautuk Consulc29554f2012-03-26 06:47:54 +0000272
273 /* No need to up_read(&mm->mmap_sem) as we would
274 * have already released it in __lock_page_or_retry
275 * in mm/filemap.c.
276 */
277
278 goto retry;
279 }
David S. Millera084b662010-01-20 03:04:14 -0800280 }
Kautuk Consulc29554f2012-03-26 06:47:54 +0000281
Linus Torvalds1da177e2005-04-16 15:20:36 -0700282 up_read(&mm->mmap_sem);
283 return;
284
285 /*
286 * Something tried to access memory that isn't in our memory map..
287 * Fix it, but check if it's kernel or user first..
288 */
289bad_area:
290 up_read(&mm->mmap_sem);
291
292bad_area_nosemaphore:
293 /* User mode accesses just cause a SIGSEGV */
David S. Miller4b177642010-03-01 00:02:23 -0800294 if (from_user) {
295 do_fault_siginfo(code, SIGSEGV, regs, text_fault);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700296 return;
297 }
298
299 /* Is this in ex_table? */
300no_context:
301 g2 = regs->u_regs[UREG_G2];
Sam Ravnborg01571412009-01-06 12:52:41 -0800302 if (!from_user) {
303 fixup = search_extables_range(regs->pc, &g2);
Sam Ravnborg70168df2012-05-15 19:02:08 +0200304 /* Values below 10 are reserved for other things */
305 if (fixup > 10) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700306 extern const unsigned __memset_start[];
307 extern const unsigned __memset_end[];
308 extern const unsigned __csum_partial_copy_start[];
309 extern const unsigned __csum_partial_copy_end[];
310
311#ifdef DEBUG_EXCEPTIONS
Sam Ravnborg70168df2012-05-15 19:02:08 +0200312 printk("Exception: PC<%08lx> faddr<%08lx>\n",
313 regs->pc, address);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700314 printk("EX_TABLE: insn<%08lx> fixup<%08x> g2<%08lx>\n",
315 regs->pc, fixup, g2);
316#endif
317 if ((regs->pc >= (unsigned long)__memset_start &&
318 regs->pc < (unsigned long)__memset_end) ||
319 (regs->pc >= (unsigned long)__csum_partial_copy_start &&
320 regs->pc < (unsigned long)__csum_partial_copy_end)) {
Sam Ravnborg70168df2012-05-15 19:02:08 +0200321 regs->u_regs[UREG_I4] = address;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700322 regs->u_regs[UREG_I5] = regs->pc;
323 }
324 regs->u_regs[UREG_G2] = g2;
325 regs->pc = fixup;
326 regs->npc = regs->pc + 4;
327 return;
328 }
329 }
Sam Ravnborg70168df2012-05-15 19:02:08 +0200330
331 unhandled_fault(address, tsk, regs);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700332 do_exit(SIGKILL);
333
334/*
335 * We ran out of memory, or some other thing happened to us that made
336 * us unable to handle the page fault gracefully.
337 */
338out_of_memory:
339 up_read(&mm->mmap_sem);
David S. Millera923c282009-08-02 19:17:15 -0700340 if (from_user) {
341 pagefault_out_of_memory();
342 return;
343 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700344 goto no_context;
345
346do_sigbus:
347 up_read(&mm->mmap_sem);
David S. Miller4b177642010-03-01 00:02:23 -0800348 do_fault_siginfo(BUS_ADRERR, SIGBUS, regs, text_fault);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700349 if (!from_user)
350 goto no_context;
351
352vmalloc_fault:
353 {
354 /*
355 * Synchronize this task's top level page-table
356 * with the 'reference' page table.
357 */
358 int offset = pgd_index(address);
359 pgd_t *pgd, *pgd_k;
360 pmd_t *pmd, *pmd_k;
361
362 pgd = tsk->active_mm->pgd + offset;
363 pgd_k = init_mm.pgd + offset;
364
365 if (!pgd_present(*pgd)) {
366 if (!pgd_present(*pgd_k))
367 goto bad_area_nosemaphore;
368 pgd_val(*pgd) = pgd_val(*pgd_k);
369 return;
370 }
371
372 pmd = pmd_offset(pgd, address);
373 pmd_k = pmd_offset(pgd_k, address);
374
375 if (pmd_present(*pmd) || !pmd_present(*pmd_k))
376 goto bad_area_nosemaphore;
Sam Ravnborg70168df2012-05-15 19:02:08 +0200377
Linus Torvalds1da177e2005-04-16 15:20:36 -0700378 *pmd = *pmd_k;
379 return;
380 }
381}
382
Linus Torvalds1da177e2005-04-16 15:20:36 -0700383/* This always deals with user addresses. */
Adrian Bunk50215d62008-06-05 11:41:51 -0700384static void force_user_fault(unsigned long address, int write)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700385{
386 struct vm_area_struct *vma;
387 struct task_struct *tsk = current;
388 struct mm_struct *mm = tsk->mm;
Johannes Weiner759496b2013-09-12 15:13:39 -0700389 unsigned int flags = FAULT_FLAG_USER;
David S. Miller4b177642010-03-01 00:02:23 -0800390 int code;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700391
David S. Miller4b177642010-03-01 00:02:23 -0800392 code = SEGV_MAPERR;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700393
Linus Torvalds1da177e2005-04-16 15:20:36 -0700394 down_read(&mm->mmap_sem);
395 vma = find_vma(mm, address);
Sam Ravnborg70168df2012-05-15 19:02:08 +0200396 if (!vma)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700397 goto bad_area;
Sam Ravnborg70168df2012-05-15 19:02:08 +0200398 if (vma->vm_start <= address)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700399 goto good_area;
Sam Ravnborg70168df2012-05-15 19:02:08 +0200400 if (!(vma->vm_flags & VM_GROWSDOWN))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700401 goto bad_area;
Sam Ravnborg70168df2012-05-15 19:02:08 +0200402 if (expand_stack(vma, address))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700403 goto bad_area;
404good_area:
David S. Miller4b177642010-03-01 00:02:23 -0800405 code = SEGV_ACCERR;
Sam Ravnborg70168df2012-05-15 19:02:08 +0200406 if (write) {
407 if (!(vma->vm_flags & VM_WRITE))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700408 goto bad_area;
Johannes Weiner759496b2013-09-12 15:13:39 -0700409 flags |= FAULT_FLAG_WRITE;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700410 } else {
Sam Ravnborg70168df2012-05-15 19:02:08 +0200411 if (!(vma->vm_flags & (VM_READ | VM_EXEC)))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700412 goto bad_area;
413 }
Johannes Weiner759496b2013-09-12 15:13:39 -0700414 switch (handle_mm_fault(mm, vma, address, flags)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700415 case VM_FAULT_SIGBUS:
416 case VM_FAULT_OOM:
417 goto do_sigbus;
418 }
419 up_read(&mm->mmap_sem);
420 return;
421bad_area:
422 up_read(&mm->mmap_sem);
David S. Miller4b177642010-03-01 00:02:23 -0800423 __do_fault_siginfo(code, SIGSEGV, tsk->thread.kregs, address);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700424 return;
425
426do_sigbus:
427 up_read(&mm->mmap_sem);
David S. Miller4b177642010-03-01 00:02:23 -0800428 __do_fault_siginfo(BUS_ADRERR, SIGBUS, tsk->thread.kregs, address);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700429}
430
David S. Miller90883332010-09-23 22:06:47 -0700431static void check_stack_aligned(unsigned long sp)
432{
433 if (sp & 0x7UL)
434 force_sig(SIGILL, current);
435}
436
Linus Torvalds1da177e2005-04-16 15:20:36 -0700437void window_overflow_fault(void)
438{
439 unsigned long sp;
440
441 sp = current_thread_info()->rwbuf_stkptrs[0];
Sam Ravnborg70168df2012-05-15 19:02:08 +0200442 if (((sp + 0x38) & PAGE_MASK) != (sp & PAGE_MASK))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700443 force_user_fault(sp + 0x38, 1);
444 force_user_fault(sp, 1);
David S. Miller90883332010-09-23 22:06:47 -0700445
446 check_stack_aligned(sp);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700447}
448
449void window_underflow_fault(unsigned long sp)
450{
Sam Ravnborg70168df2012-05-15 19:02:08 +0200451 if (((sp + 0x38) & PAGE_MASK) != (sp & PAGE_MASK))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700452 force_user_fault(sp + 0x38, 0);
453 force_user_fault(sp, 0);
David S. Miller90883332010-09-23 22:06:47 -0700454
455 check_stack_aligned(sp);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700456}
457
458void window_ret_fault(struct pt_regs *regs)
459{
460 unsigned long sp;
461
462 sp = regs->u_regs[UREG_FP];
Sam Ravnborg70168df2012-05-15 19:02:08 +0200463 if (((sp + 0x38) & PAGE_MASK) != (sp & PAGE_MASK))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700464 force_user_fault(sp + 0x38, 0);
465 force_user_fault(sp, 0);
David S. Miller90883332010-09-23 22:06:47 -0700466
467 check_stack_aligned(sp);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700468}