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-rw-r--r--arch/arm26/mm/fault.c312
1 files changed, 0 insertions, 312 deletions
diff --git a/arch/arm26/mm/fault.c b/arch/arm26/mm/fault.c
deleted file mode 100644
index dec638a0c8d..00000000000
--- a/arch/arm26/mm/fault.c
+++ /dev/null
@@ -1,312 +0,0 @@
1/*
2 * linux/arch/arm26/mm/fault.c
3 *
4 * Copyright (C) 1995 Linus Torvalds
5 * Modifications for ARM processor (c) 1995-2001 Russell King
6 *
7 * This program is free software; you can redistribute it and/or modify
8 * it under the terms of the GNU General Public License version 2 as
9 * published by the Free Software Foundation.
10 */
11#include <linux/signal.h>
12#include <linux/sched.h>
13#include <linux/kernel.h>
14#include <linux/errno.h>
15#include <linux/string.h>
16#include <linux/types.h>
17#include <linux/ptrace.h>
18#include <linux/mman.h>
19#include <linux/mm.h>
20#include <linux/interrupt.h>
21#include <linux/proc_fs.h>
22#include <linux/init.h>
23
24#include <asm/system.h>
25#include <asm/pgtable.h>
26#include <asm/uaccess.h> //FIXME this header may be bogusly included
27
28#include "fault.h"
29
30#define FAULT_CODE_LDRSTRPOST 0x80
31#define FAULT_CODE_LDRSTRPRE 0x40
32#define FAULT_CODE_LDRSTRREG 0x20
33#define FAULT_CODE_LDMSTM 0x10
34#define FAULT_CODE_LDCSTC 0x08
35#define FAULT_CODE_PREFETCH 0x04
36#define FAULT_CODE_WRITE 0x02
37#define FAULT_CODE_FORCECOW 0x01
38
39#define DO_COW(m) ((m) & (FAULT_CODE_WRITE|FAULT_CODE_FORCECOW))
40#define READ_FAULT(m) (!((m) & FAULT_CODE_WRITE))
41#define DEBUG
42/*
43 * This is useful to dump out the page tables associated with
44 * 'addr' in mm 'mm'.
45 */
46void show_pte(struct mm_struct *mm, unsigned long addr)
47{
48 pgd_t *pgd;
49
50 if (!mm)
51 mm = &init_mm;
52
53 printk(KERN_ALERT "pgd = %p\n", mm->pgd);
54 pgd = pgd_offset(mm, addr);
55 printk(KERN_ALERT "[%08lx] *pgd=%08lx", addr, pgd_val(*pgd));
56
57 do {
58 pmd_t *pmd;
59 pte_t *pte;
60
61 pmd = pmd_offset(pgd, addr);
62
63 if (pmd_none(*pmd))
64 break;
65
66 if (pmd_bad(*pmd)) {
67 printk("(bad)");
68 break;
69 }
70
71 /* We must not map this if we have highmem enabled */
72 /* FIXME */
73 pte = pte_offset_map(pmd, addr);
74 printk(", *pte=%08lx", pte_val(*pte));
75 pte_unmap(pte);
76 } while(0);
77
78 printk("\n");
79}
80
81/*
82 * Oops. The kernel tried to access some page that wasn't present.
83 */
84static void
85__do_kernel_fault(struct mm_struct *mm, unsigned long addr, unsigned int fsr,
86 struct pt_regs *regs)
87{
88 /*
89 * Are we prepared to handle this kernel fault?
90 */
91 if (fixup_exception(regs))
92 return;
93
94 /*
95 * No handler, we'll have to terminate things with extreme prejudice.
96 */
97 bust_spinlocks(1);
98 printk(KERN_ALERT
99 "Unable to handle kernel %s at virtual address %08lx\n",
100 (addr < PAGE_SIZE) ? "NULL pointer dereference" :
101 "paging request", addr);
102
103 show_pte(mm, addr);
104 die("Oops", regs, fsr);
105 bust_spinlocks(0);
106 do_exit(SIGKILL);
107}
108
109/*
110 * Something tried to access memory that isn't in our memory map..
111 * User mode accesses just cause a SIGSEGV
112 */
113static void
114__do_user_fault(struct task_struct *tsk, unsigned long addr,
115 unsigned int fsr, int code, struct pt_regs *regs)
116{
117 struct siginfo si;
118
119#ifdef CONFIG_DEBUG_USER
120 printk("%s: unhandled page fault at 0x%08lx, code 0x%03x\n",
121 tsk->comm, addr, fsr);
122 show_pte(tsk->mm, addr);
123 show_regs(regs);
124 //dump_backtrace(regs, tsk); // FIXME ARM32 dropped this - why?
125 while(1); //FIXME - hack to stop debug going nutso
126#endif
127
128 tsk->thread.address = addr;
129 tsk->thread.error_code = fsr;
130 tsk->thread.trap_no = 14;
131 si.si_signo = SIGSEGV;
132 si.si_errno = 0;
133 si.si_code = code;
134 si.si_addr = (void *)addr;
135 force_sig_info(SIGSEGV, &si, tsk);
136}
137
138static int
139__do_page_fault(struct mm_struct *mm, unsigned long addr, unsigned int fsr,
140 struct task_struct *tsk)
141{
142 struct vm_area_struct *vma;
143 int fault, mask;
144
145 vma = find_vma(mm, addr);
146 fault = -2; /* bad map area */
147 if (!vma)
148 goto out;
149 if (vma->vm_start > addr)
150 goto check_stack;
151
152 /*
153 * Ok, we have a good vm_area for this
154 * memory access, so we can handle it.
155 */
156good_area:
157 if (READ_FAULT(fsr)) /* read? */
158 mask = VM_READ|VM_EXEC|VM_WRITE;
159 else
160 mask = VM_WRITE;
161
162 fault = -1; /* bad access type */
163 if (!(vma->vm_flags & mask))
164 goto out;
165
166 /*
167 * If for any reason at all we couldn't handle
168 * the fault, make sure we exit gracefully rather
169 * than endlessly redo the fault.
170 */
171survive:
172 fault = handle_mm_fault(mm, vma, addr & PAGE_MASK, DO_COW(fsr));
173 if (unlikely(fault & VM_FAULT_ERROR)) {
174 if (fault & VM_FAULT_OOM)
175 goto out_of_memory;
176 else if (fault & VM_FAULT_SIGBUS)
177 return fault;
178 BUG();
179 }
180 if (fault & VM_FAULT_MAJOR)
181 tsk->maj_flt++;
182 else
183 tsk->min_flt++;
184 return fault;
185
186out_of_memory:
187 fault = -3; /* out of memory */
188 if (!is_init(tsk))
189 goto out;
190
191 /*
192 * If we are out of memory for pid1,
193 * sleep for a while and retry
194 */
195 yield();
196 goto survive;
197
198check_stack:
199 if (vma->vm_flags & VM_GROWSDOWN && !expand_stack(vma, addr))
200 goto good_area;
201out:
202 return fault;
203}
204
205int do_page_fault(unsigned long addr, unsigned int fsr, struct pt_regs *regs)
206{
207 struct task_struct *tsk;
208 struct mm_struct *mm;
209 int fault;
210
211 tsk = current;
212 mm = tsk->mm;
213
214 /*
215 * If we're in an interrupt or have no user
216 * context, we must not take the fault..
217 */
218 if (in_atomic() || !mm)
219 goto no_context;
220
221 down_read(&mm->mmap_sem);
222 fault = __do_page_fault(mm, addr, fsr, tsk);
223 up_read(&mm->mmap_sem);
224
225 /*
226 * Handle the "normal" case first
227 */
228 if (likely(!(fault & VM_FAULT_ERROR)))
229 return 0;
230 if (fault & VM_FAULT_SIGBUS)
231 goto do_sigbus;
232 /* else VM_FAULT_OOM */
233
234 /*
235 * If we are in kernel mode at this point, we
236 * have no context to handle this fault with.
237 * FIXME - is this test right?
238 */
239 if (!user_mode(regs)){
240 goto no_context;
241 }
242
243 if (fault == -3) {
244 /*
245 * We ran out of memory, or some other thing happened to
246 * us that made us unable to handle the page fault gracefully.
247 */
248 printk("VM: killing process %s\n", tsk->comm);
249 do_exit(SIGKILL);
250 }
251 else{
252 __do_user_fault(tsk, addr, fsr, fault == -1 ? SEGV_ACCERR : SEGV_MAPERR, regs);
253 }
254
255 return 0;
256
257
258/*
259 * We ran out of memory, or some other thing happened to us that made
260 * us unable to handle the page fault gracefully.
261 */
262do_sigbus:
263 /*
264 * Send a sigbus, regardless of whether we were in kernel
265 * or user mode.
266 */
267 tsk->thread.address = addr; //FIXME - need other bits setting?
268 tsk->thread.error_code = fsr;
269 tsk->thread.trap_no = 14;
270 force_sig(SIGBUS, tsk);
271#ifdef CONFIG_DEBUG_USER
272 printk(KERN_DEBUG "%s: sigbus at 0x%08lx, pc=0x%08lx\n",
273 current->comm, addr, instruction_pointer(regs));
274#endif
275
276 /* Kernel mode? Handle exceptions or die */
277 if (user_mode(regs))
278 return 0;
279
280no_context:
281 __do_kernel_fault(mm, addr, fsr, regs);
282 return 0;
283}
284
285/*
286 * Handle a data abort. Note that we have to handle a range of addresses
287 * on ARM2/3 for ldm. If both pages are zero-mapped, then we have to force
288 * a copy-on-write. However, on the second page, we always force COW.
289 */
290asmlinkage void
291do_DataAbort(unsigned long min_addr, unsigned long max_addr, int mode, struct pt_regs *regs)
292{
293 do_page_fault(min_addr, mode, regs);
294
295 if ((min_addr ^ max_addr) >> PAGE_SHIFT){
296 do_page_fault(max_addr, mode | FAULT_CODE_FORCECOW, regs);
297 }
298}
299
300asmlinkage int
301do_PrefetchAbort(unsigned long addr, struct pt_regs *regs)
302{
303#if 0
304 if (the memc mapping for this page exists) {
305 printk ("Page in, but got abort (undefined instruction?)\n");
306 return 0;
307 }
308#endif
309 do_page_fault(addr, FAULT_CODE_PREFETCH, regs);
310 return 1;
311}
312
generated by cgit v1.2.2 (git 2.25.0) at 2025-01-19 22:56:21 -0500