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1// SPDX-License-Identifier: GPL-2.0
2/*
3 * fault.c: Page fault handlers for the Sparc.
4 *
5 * Copyright (C) 1995 David S. Miller (davem@caip.rutgers.edu)
6 * Copyright (C) 1996 Eddie C. Dost (ecd@skynet.be)
7 * Copyright (C) 1997 Jakub Jelinek (jj@sunsite.mff.cuni.cz)
8 */
9
10#include <asm/head.h>
11
12#include <linux/string.h>
13#include <linux/types.h>
14#include <linux/sched.h>
15#include <linux/ptrace.h>
16#include <linux/mman.h>
17#include <linux/threads.h>
18#include <linux/kernel.h>
19#include <linux/signal.h>
20#include <linux/mm.h>
21#include <linux/smp.h>
22#include <linux/perf_event.h>
23#include <linux/interrupt.h>
24#include <linux/kdebug.h>
25#include <linux/uaccess.h>
26#include <linux/extable.h>
27
28#include <asm/page.h>
29#include <asm/openprom.h>
30#include <asm/oplib.h>
31#include <asm/setup.h>
32#include <asm/smp.h>
33#include <asm/traps.h>
34
35#include "mm_32.h"
36
37int show_unhandled_signals = 1;
38
39static void __noreturn unhandled_fault(unsigned long address,
40 struct task_struct *tsk,
41 struct pt_regs *regs)
42{
43 if ((unsigned long) address < PAGE_SIZE) {
44 printk(KERN_ALERT
45 "Unable to handle kernel NULL pointer dereference\n");
46 } else {
47 printk(KERN_ALERT "Unable to handle kernel paging request at virtual address %08lx\n",
48 address);
49 }
50 printk(KERN_ALERT "tsk->{mm,active_mm}->context = %08lx\n",
51 (tsk->mm ? tsk->mm->context : tsk->active_mm->context));
52 printk(KERN_ALERT "tsk->{mm,active_mm}->pgd = %08lx\n",
53 (tsk->mm ? (unsigned long) tsk->mm->pgd :
54 (unsigned long) tsk->active_mm->pgd));
55 die_if_kernel("Oops", regs);
56}
57
58static inline void
59show_signal_msg(struct pt_regs *regs, int sig, int code,
60 unsigned long address, struct task_struct *tsk)
61{
62 if (!unhandled_signal(tsk, sig))
63 return;
64
65 if (!printk_ratelimit())
66 return;
67
68 printk("%s%s[%d]: segfault at %lx ip %px (rpc %px) sp %px error %x",
69 task_pid_nr(tsk) > 1 ? KERN_INFO : KERN_EMERG,
70 tsk->comm, task_pid_nr(tsk), address,
71 (void *)regs->pc, (void *)regs->u_regs[UREG_I7],
72 (void *)regs->u_regs[UREG_FP], code);
73
74 print_vma_addr(KERN_CONT " in ", regs->pc);
75
76 printk(KERN_CONT "\n");
77}
78
79static void __do_fault_siginfo(int code, int sig, struct pt_regs *regs,
80 unsigned long addr)
81{
82 if (unlikely(show_unhandled_signals))
83 show_signal_msg(regs, sig, code,
84 addr, current);
85
86 force_sig_fault(sig, code, (void __user *) addr);
87}
88
89static unsigned long compute_si_addr(struct pt_regs *regs, int text_fault)
90{
91 unsigned int insn;
92
93 if (text_fault)
94 return regs->pc;
95
96 if (regs->psr & PSR_PS)
97 insn = *(unsigned int *) regs->pc;
98 else
99 __get_user(insn, (unsigned int *) regs->pc);
100
101 return safe_compute_effective_address(regs, insn);
102}
103
104static noinline void do_fault_siginfo(int code, int sig, struct pt_regs *regs,
105 int text_fault)
106{
107 unsigned long addr = compute_si_addr(regs, text_fault);
108
109 __do_fault_siginfo(code, sig, regs, addr);
110}
111
112asmlinkage void do_sparc_fault(struct pt_regs *regs, int text_fault, int write,
113 unsigned long address)
114{
115 struct vm_area_struct *vma;
116 struct task_struct *tsk = current;
117 struct mm_struct *mm = tsk->mm;
118 int from_user = !(regs->psr & PSR_PS);
119 int code;
120 vm_fault_t fault;
121 unsigned int flags = FAULT_FLAG_DEFAULT;
122
123 if (text_fault)
124 address = regs->pc;
125
126 /*
127 * We fault-in kernel-space virtual memory on-demand. The
128 * 'reference' page table is init_mm.pgd.
129 *
130 * NOTE! We MUST NOT take any locks for this case. We may
131 * be in an interrupt or a critical region, and should
132 * only copy the information from the master page table,
133 * nothing more.
134 */
135 code = SEGV_MAPERR;
136 if (address >= TASK_SIZE)
137 goto vmalloc_fault;
138
139 /*
140 * If we're in an interrupt or have no user
141 * context, we must not take the fault..
142 */
143 if (pagefault_disabled() || !mm)
144 goto no_context;
145
146 if (!from_user && address >= PAGE_OFFSET)
147 goto no_context;
148
149 perf_sw_event(PERF_COUNT_SW_PAGE_FAULTS, 1, regs, address);
150
151retry:
152 vma = lock_mm_and_find_vma(mm, address, regs);
153 if (!vma)
154 goto bad_area_nosemaphore;
155 /*
156 * Ok, we have a good vm_area for this memory access, so
157 * we can handle it..
158 */
159 code = SEGV_ACCERR;
160 if (write) {
161 if (!(vma->vm_flags & VM_WRITE))
162 goto bad_area;
163 } else {
164 /* Allow reads even for write-only mappings */
165 if (!(vma->vm_flags & (VM_READ | VM_EXEC)))
166 goto bad_area;
167 }
168
169 if (from_user)
170 flags |= FAULT_FLAG_USER;
171 if (write)
172 flags |= FAULT_FLAG_WRITE;
173
174 /*
175 * If for any reason at all we couldn't handle the fault,
176 * make sure we exit gracefully rather than endlessly redo
177 * the fault.
178 */
179 fault = handle_mm_fault(vma, address, flags, regs);
180
181 if (fault_signal_pending(fault, regs)) {
182 if (!from_user)
183 goto no_context;
184 return;
185 }
186
187 /* The fault is fully completed (including releasing mmap lock) */
188 if (fault & VM_FAULT_COMPLETED)
189 return;
190
191 if (unlikely(fault & VM_FAULT_ERROR)) {
192 if (fault & VM_FAULT_OOM)
193 goto out_of_memory;
194 else if (fault & VM_FAULT_SIGSEGV)
195 goto bad_area;
196 else if (fault & VM_FAULT_SIGBUS)
197 goto do_sigbus;
198 BUG();
199 }
200
201 if (fault & VM_FAULT_RETRY) {
202 flags |= FAULT_FLAG_TRIED;
203
204 /* No need to mmap_read_unlock(mm) as we would
205 * have already released it in __lock_page_or_retry
206 * in mm/filemap.c.
207 */
208
209 goto retry;
210 }
211
212 mmap_read_unlock(mm);
213 return;
214
215 /*
216 * Something tried to access memory that isn't in our memory map..
217 * Fix it, but check if it's kernel or user first..
218 */
219bad_area:
220 mmap_read_unlock(mm);
221
222bad_area_nosemaphore:
223 /* User mode accesses just cause a SIGSEGV */
224 if (from_user) {
225 do_fault_siginfo(code, SIGSEGV, regs, text_fault);
226 return;
227 }
228
229 /* Is this in ex_table? */
230no_context:
231 if (!from_user) {
232 const struct exception_table_entry *entry;
233
234 entry = search_exception_tables(regs->pc);
235#ifdef DEBUG_EXCEPTIONS
236 printk("Exception: PC<%08lx> faddr<%08lx>\n",
237 regs->pc, address);
238 printk("EX_TABLE: insn<%08lx> fixup<%08x>\n",
239 regs->pc, entry->fixup);
240#endif
241 regs->pc = entry->fixup;
242 regs->npc = regs->pc + 4;
243 return;
244 }
245
246 unhandled_fault(address, tsk, regs);
247
248/*
249 * We ran out of memory, or some other thing happened to us that made
250 * us unable to handle the page fault gracefully.
251 */
252out_of_memory:
253 mmap_read_unlock(mm);
254 if (from_user) {
255 pagefault_out_of_memory();
256 return;
257 }
258 goto no_context;
259
260do_sigbus:
261 mmap_read_unlock(mm);
262 do_fault_siginfo(BUS_ADRERR, SIGBUS, regs, text_fault);
263 if (!from_user)
264 goto no_context;
265
266vmalloc_fault:
267 {
268 /*
269 * Synchronize this task's top level page-table
270 * with the 'reference' page table.
271 */
272 int offset = pgd_index(address);
273 pgd_t *pgd, *pgd_k;
274 p4d_t *p4d, *p4d_k;
275 pud_t *pud, *pud_k;
276 pmd_t *pmd, *pmd_k;
277
278 pgd = tsk->active_mm->pgd + offset;
279 pgd_k = init_mm.pgd + offset;
280
281 if (!pgd_present(*pgd)) {
282 if (!pgd_present(*pgd_k))
283 goto bad_area_nosemaphore;
284 pgd_val(*pgd) = pgd_val(*pgd_k);
285 return;
286 }
287
288 p4d = p4d_offset(pgd, address);
289 pud = pud_offset(p4d, address);
290 pmd = pmd_offset(pud, address);
291
292 p4d_k = p4d_offset(pgd_k, address);
293 pud_k = pud_offset(p4d_k, address);
294 pmd_k = pmd_offset(pud_k, address);
295
296 if (pmd_present(*pmd) || !pmd_present(*pmd_k))
297 goto bad_area_nosemaphore;
298
299 *pmd = *pmd_k;
300 return;
301 }
302}
303
304/* This always deals with user addresses. */
305static void force_user_fault(unsigned long address, int write)
306{
307 struct vm_area_struct *vma;
308 struct task_struct *tsk = current;
309 struct mm_struct *mm = tsk->mm;
310 unsigned int flags = FAULT_FLAG_USER;
311 int code;
312
313 code = SEGV_MAPERR;
314
315 vma = lock_mm_and_find_vma(mm, address, NULL);
316 if (!vma)
317 goto bad_area_nosemaphore;
318 code = SEGV_ACCERR;
319 if (write) {
320 if (!(vma->vm_flags & VM_WRITE))
321 goto bad_area;
322 flags |= FAULT_FLAG_WRITE;
323 } else {
324 if (!(vma->vm_flags & (VM_READ | VM_EXEC)))
325 goto bad_area;
326 }
327 switch (handle_mm_fault(vma, address, flags, NULL)) {
328 case VM_FAULT_SIGBUS:
329 case VM_FAULT_OOM:
330 goto do_sigbus;
331 }
332 mmap_read_unlock(mm);
333 return;
334bad_area:
335 mmap_read_unlock(mm);
336bad_area_nosemaphore:
337 __do_fault_siginfo(code, SIGSEGV, tsk->thread.kregs, address);
338 return;
339
340do_sigbus:
341 mmap_read_unlock(mm);
342 __do_fault_siginfo(BUS_ADRERR, SIGBUS, tsk->thread.kregs, address);
343}
344
345static void check_stack_aligned(unsigned long sp)
346{
347 if (sp & 0x7UL)
348 force_sig(SIGILL);
349}
350
351void window_overflow_fault(void)
352{
353 unsigned long sp;
354
355 sp = current_thread_info()->rwbuf_stkptrs[0];
356 if (((sp + 0x38) & PAGE_MASK) != (sp & PAGE_MASK))
357 force_user_fault(sp + 0x38, 1);
358 force_user_fault(sp, 1);
359
360 check_stack_aligned(sp);
361}
362
363void window_underflow_fault(unsigned long sp)
364{
365 if (((sp + 0x38) & PAGE_MASK) != (sp & PAGE_MASK))
366 force_user_fault(sp + 0x38, 0);
367 force_user_fault(sp, 0);
368
369 check_stack_aligned(sp);
370}
371
372void window_ret_fault(struct pt_regs *regs)
373{
374 unsigned long sp;
375
376 sp = regs->u_regs[UREG_FP];
377 if (((sp + 0x38) & PAGE_MASK) != (sp & PAGE_MASK))
378 force_user_fault(sp + 0x38, 0);
379 force_user_fault(sp, 0);
380
381 check_stack_aligned(sp);
382}
1// SPDX-License-Identifier: GPL-2.0
2/*
3 * fault.c: Page fault handlers for the Sparc.
4 *
5 * Copyright (C) 1995 David S. Miller (davem@caip.rutgers.edu)
6 * Copyright (C) 1996 Eddie C. Dost (ecd@skynet.be)
7 * Copyright (C) 1997 Jakub Jelinek (jj@sunsite.mff.cuni.cz)
8 */
9
10#include <asm/head.h>
11
12#include <linux/string.h>
13#include <linux/types.h>
14#include <linux/sched.h>
15#include <linux/ptrace.h>
16#include <linux/mman.h>
17#include <linux/threads.h>
18#include <linux/kernel.h>
19#include <linux/signal.h>
20#include <linux/mm.h>
21#include <linux/smp.h>
22#include <linux/perf_event.h>
23#include <linux/interrupt.h>
24#include <linux/kdebug.h>
25#include <linux/uaccess.h>
26
27#include <asm/page.h>
28#include <asm/openprom.h>
29#include <asm/oplib.h>
30#include <asm/setup.h>
31#include <asm/smp.h>
32#include <asm/traps.h>
33
34#include "mm_32.h"
35
36int show_unhandled_signals = 1;
37
38static void __noreturn unhandled_fault(unsigned long address,
39 struct task_struct *tsk,
40 struct pt_regs *regs)
41{
42 if ((unsigned long) address < PAGE_SIZE) {
43 printk(KERN_ALERT
44 "Unable to handle kernel NULL pointer dereference\n");
45 } else {
46 printk(KERN_ALERT "Unable to handle kernel paging request at virtual address %08lx\n",
47 address);
48 }
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 :
53 (unsigned long) tsk->active_mm->pgd));
54 die_if_kernel("Oops", regs);
55}
56
57asmlinkage int lookup_fault(unsigned long pc, unsigned long ret_pc,
58 unsigned long address)
59{
60 struct pt_regs regs;
61 unsigned long g2;
62 unsigned int insn;
63 int i;
64
65 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)
84 return 2;
85 break;
86
87 default:
88 break;
89 }
90
91 memset(®s, 0, sizeof(regs));
92 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, ®s);
100
101 /* Not reached */
102 return 0;
103}
104
105static 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 %px (rpc %px) sp %px 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 if (unlikely(show_unhandled_signals))
130 show_signal_msg(regs, sig, code,
131 addr, current);
132
133 force_sig_fault(sig, code, (void __user *) addr, 0);
134}
135
136static unsigned long compute_si_addr(struct pt_regs *regs, int text_fault)
137{
138 unsigned int insn;
139
140 if (text_fault)
141 return regs->pc;
142
143 if (regs->psr & PSR_PS)
144 insn = *(unsigned int *) regs->pc;
145 else
146 __get_user(insn, (unsigned int *) regs->pc);
147
148 return safe_compute_effective_address(regs, insn);
149}
150
151static noinline void do_fault_siginfo(int code, int sig, struct pt_regs *regs,
152 int text_fault)
153{
154 unsigned long addr = compute_si_addr(regs, text_fault);
155
156 __do_fault_siginfo(code, sig, regs, addr);
157}
158
159asmlinkage void do_sparc_fault(struct pt_regs *regs, int text_fault, int write,
160 unsigned long address)
161{
162 struct vm_area_struct *vma;
163 struct task_struct *tsk = current;
164 struct mm_struct *mm = tsk->mm;
165 unsigned int fixup;
166 unsigned long g2;
167 int from_user = !(regs->psr & PSR_PS);
168 int code;
169 vm_fault_t fault;
170 unsigned int flags = FAULT_FLAG_DEFAULT;
171
172 if (text_fault)
173 address = regs->pc;
174
175 /*
176 * We fault-in kernel-space virtual memory on-demand. The
177 * 'reference' page table is init_mm.pgd.
178 *
179 * NOTE! We MUST NOT take any locks for this case. We may
180 * be in an interrupt or a critical region, and should
181 * only copy the information from the master page table,
182 * nothing more.
183 */
184 code = SEGV_MAPERR;
185 if (address >= TASK_SIZE)
186 goto vmalloc_fault;
187
188 /*
189 * If we're in an interrupt or have no user
190 * context, we must not take the fault..
191 */
192 if (pagefault_disabled() || !mm)
193 goto no_context;
194
195 perf_sw_event(PERF_COUNT_SW_PAGE_FAULTS, 1, regs, address);
196
197retry:
198 mmap_read_lock(mm);
199
200 if (!from_user && address >= PAGE_OFFSET)
201 goto bad_area;
202
203 vma = find_vma(mm, address);
204 if (!vma)
205 goto bad_area;
206 if (vma->vm_start <= address)
207 goto good_area;
208 if (!(vma->vm_flags & VM_GROWSDOWN))
209 goto bad_area;
210 if (expand_stack(vma, address))
211 goto bad_area;
212 /*
213 * Ok, we have a good vm_area for this memory access, so
214 * we can handle it..
215 */
216good_area:
217 code = SEGV_ACCERR;
218 if (write) {
219 if (!(vma->vm_flags & VM_WRITE))
220 goto bad_area;
221 } else {
222 /* Allow reads even for write-only mappings */
223 if (!(vma->vm_flags & (VM_READ | VM_EXEC)))
224 goto bad_area;
225 }
226
227 if (from_user)
228 flags |= FAULT_FLAG_USER;
229 if (write)
230 flags |= FAULT_FLAG_WRITE;
231
232 /*
233 * If for any reason at all we couldn't handle the fault,
234 * make sure we exit gracefully rather than endlessly redo
235 * the fault.
236 */
237 fault = handle_mm_fault(vma, address, flags, regs);
238
239 if (fault_signal_pending(fault, regs))
240 return;
241
242 if (unlikely(fault & VM_FAULT_ERROR)) {
243 if (fault & VM_FAULT_OOM)
244 goto out_of_memory;
245 else if (fault & VM_FAULT_SIGSEGV)
246 goto bad_area;
247 else if (fault & VM_FAULT_SIGBUS)
248 goto do_sigbus;
249 BUG();
250 }
251
252 if (flags & FAULT_FLAG_ALLOW_RETRY) {
253 if (fault & VM_FAULT_RETRY) {
254 flags |= FAULT_FLAG_TRIED;
255
256 /* No need to mmap_read_unlock(mm) as we would
257 * have already released it in __lock_page_or_retry
258 * in mm/filemap.c.
259 */
260
261 goto retry;
262 }
263 }
264
265 mmap_read_unlock(mm);
266 return;
267
268 /*
269 * Something tried to access memory that isn't in our memory map..
270 * Fix it, but check if it's kernel or user first..
271 */
272bad_area:
273 mmap_read_unlock(mm);
274
275bad_area_nosemaphore:
276 /* User mode accesses just cause a SIGSEGV */
277 if (from_user) {
278 do_fault_siginfo(code, SIGSEGV, regs, text_fault);
279 return;
280 }
281
282 /* Is this in ex_table? */
283no_context:
284 g2 = regs->u_regs[UREG_G2];
285 if (!from_user) {
286 fixup = search_extables_range(regs->pc, &g2);
287 /* Values below 10 are reserved for other things */
288 if (fixup > 10) {
289 extern const unsigned int __memset_start[];
290 extern const unsigned int __memset_end[];
291 extern const unsigned int __csum_partial_copy_start[];
292 extern const unsigned int __csum_partial_copy_end[];
293
294#ifdef DEBUG_EXCEPTIONS
295 printk("Exception: PC<%08lx> faddr<%08lx>\n",
296 regs->pc, address);
297 printk("EX_TABLE: insn<%08lx> fixup<%08x> g2<%08lx>\n",
298 regs->pc, fixup, g2);
299#endif
300 if ((regs->pc >= (unsigned long)__memset_start &&
301 regs->pc < (unsigned long)__memset_end) ||
302 (regs->pc >= (unsigned long)__csum_partial_copy_start &&
303 regs->pc < (unsigned long)__csum_partial_copy_end)) {
304 regs->u_regs[UREG_I4] = address;
305 regs->u_regs[UREG_I5] = regs->pc;
306 }
307 regs->u_regs[UREG_G2] = g2;
308 regs->pc = fixup;
309 regs->npc = regs->pc + 4;
310 return;
311 }
312 }
313
314 unhandled_fault(address, tsk, regs);
315 do_exit(SIGKILL);
316
317/*
318 * We ran out of memory, or some other thing happened to us that made
319 * us unable to handle the page fault gracefully.
320 */
321out_of_memory:
322 mmap_read_unlock(mm);
323 if (from_user) {
324 pagefault_out_of_memory();
325 return;
326 }
327 goto no_context;
328
329do_sigbus:
330 mmap_read_unlock(mm);
331 do_fault_siginfo(BUS_ADRERR, SIGBUS, regs, text_fault);
332 if (!from_user)
333 goto no_context;
334
335vmalloc_fault:
336 {
337 /*
338 * Synchronize this task's top level page-table
339 * with the 'reference' page table.
340 */
341 int offset = pgd_index(address);
342 pgd_t *pgd, *pgd_k;
343 p4d_t *p4d, *p4d_k;
344 pud_t *pud, *pud_k;
345 pmd_t *pmd, *pmd_k;
346
347 pgd = tsk->active_mm->pgd + offset;
348 pgd_k = init_mm.pgd + offset;
349
350 if (!pgd_present(*pgd)) {
351 if (!pgd_present(*pgd_k))
352 goto bad_area_nosemaphore;
353 pgd_val(*pgd) = pgd_val(*pgd_k);
354 return;
355 }
356
357 p4d = p4d_offset(pgd, address);
358 pud = pud_offset(p4d, address);
359 pmd = pmd_offset(pud, address);
360
361 p4d_k = p4d_offset(pgd_k, address);
362 pud_k = pud_offset(p4d_k, address);
363 pmd_k = pmd_offset(pud_k, address);
364
365 if (pmd_present(*pmd) || !pmd_present(*pmd_k))
366 goto bad_area_nosemaphore;
367
368 *pmd = *pmd_k;
369 return;
370 }
371}
372
373/* This always deals with user addresses. */
374static void force_user_fault(unsigned long address, int write)
375{
376 struct vm_area_struct *vma;
377 struct task_struct *tsk = current;
378 struct mm_struct *mm = tsk->mm;
379 unsigned int flags = FAULT_FLAG_USER;
380 int code;
381
382 code = SEGV_MAPERR;
383
384 mmap_read_lock(mm);
385 vma = find_vma(mm, address);
386 if (!vma)
387 goto bad_area;
388 if (vma->vm_start <= address)
389 goto good_area;
390 if (!(vma->vm_flags & VM_GROWSDOWN))
391 goto bad_area;
392 if (expand_stack(vma, address))
393 goto bad_area;
394good_area:
395 code = SEGV_ACCERR;
396 if (write) {
397 if (!(vma->vm_flags & VM_WRITE))
398 goto bad_area;
399 flags |= FAULT_FLAG_WRITE;
400 } else {
401 if (!(vma->vm_flags & (VM_READ | VM_EXEC)))
402 goto bad_area;
403 }
404 switch (handle_mm_fault(vma, address, flags, NULL)) {
405 case VM_FAULT_SIGBUS:
406 case VM_FAULT_OOM:
407 goto do_sigbus;
408 }
409 mmap_read_unlock(mm);
410 return;
411bad_area:
412 mmap_read_unlock(mm);
413 __do_fault_siginfo(code, SIGSEGV, tsk->thread.kregs, address);
414 return;
415
416do_sigbus:
417 mmap_read_unlock(mm);
418 __do_fault_siginfo(BUS_ADRERR, SIGBUS, tsk->thread.kregs, address);
419}
420
421static void check_stack_aligned(unsigned long sp)
422{
423 if (sp & 0x7UL)
424 force_sig(SIGILL);
425}
426
427void window_overflow_fault(void)
428{
429 unsigned long sp;
430
431 sp = current_thread_info()->rwbuf_stkptrs[0];
432 if (((sp + 0x38) & PAGE_MASK) != (sp & PAGE_MASK))
433 force_user_fault(sp + 0x38, 1);
434 force_user_fault(sp, 1);
435
436 check_stack_aligned(sp);
437}
438
439void window_underflow_fault(unsigned long sp)
440{
441 if (((sp + 0x38) & PAGE_MASK) != (sp & PAGE_MASK))
442 force_user_fault(sp + 0x38, 0);
443 force_user_fault(sp, 0);
444
445 check_stack_aligned(sp);
446}
447
448void window_ret_fault(struct pt_regs *regs)
449{
450 unsigned long sp;
451
452 sp = regs->u_regs[UREG_FP];
453 if (((sp + 0x38) & PAGE_MASK) != (sp & PAGE_MASK))
454 force_user_fault(sp + 0x38, 0);
455 force_user_fault(sp, 0);
456
457 check_stack_aligned(sp);
458}