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10#include <linux/kernel.h>
11#include <linux/sched.h>
12#include <linux/mm.h>
13#include <asm/ptrace.h>
14#include <asm/processor.h>
15#include <asm/uaccess.h>
16#include <linux/smp.h>
17#include <linux/perf_event.h>
18
19enum direction {
20 load,
21 store,
22 both,
23 fpload,
24 fpstore,
25 invalid,
26};
27
28static inline enum direction decode_direction(unsigned int insn)
29{
30 unsigned long tmp = (insn >> 21) & 1;
31
32 if(!tmp)
33 return load;
34 else {
35 if(((insn>>19)&0x3f) == 15)
36 return both;
37 else
38 return store;
39 }
40}
41
42
43static inline int decode_access_size(unsigned int insn)
44{
45 insn = (insn >> 19) & 3;
46
47 if(!insn)
48 return 4;
49 else if(insn == 3)
50 return 8;
51 else if(insn == 2)
52 return 2;
53 else {
54 printk("Impossible unaligned trap. insn=%08x\n", insn);
55 die_if_kernel("Byte sized unaligned access?!?!", current->thread.kregs);
56 return 4;
57 }
58}
59
60
61static inline int decode_signedness(unsigned int insn)
62{
63 return (insn & 0x400000);
64}
65
66static inline void maybe_flush_windows(unsigned int rs1, unsigned int rs2,
67 unsigned int rd)
68{
69 if(rs2 >= 16 || rs1 >= 16 || rd >= 16) {
70
71 __asm__ __volatile__("save %sp, -0x40, %sp\n\t"
72 "save %sp, -0x40, %sp\n\t"
73 "save %sp, -0x40, %sp\n\t"
74 "save %sp, -0x40, %sp\n\t"
75 "save %sp, -0x40, %sp\n\t"
76 "save %sp, -0x40, %sp\n\t"
77 "save %sp, -0x40, %sp\n\t"
78 "restore; restore; restore; restore;\n\t"
79 "restore; restore; restore;\n\t");
80 }
81}
82
83static inline int sign_extend_imm13(int imm)
84{
85 return imm << 19 >> 19;
86}
87
88static inline unsigned long fetch_reg(unsigned int reg, struct pt_regs *regs)
89{
90 struct reg_window32 *win;
91
92 if(reg < 16)
93 return (!reg ? 0 : regs->u_regs[reg]);
94
95
96 win = (struct reg_window32 *) regs->u_regs[UREG_FP];
97 return win->locals[reg - 16];
98}
99
100static inline unsigned long safe_fetch_reg(unsigned int reg, struct pt_regs *regs)
101{
102 struct reg_window32 __user *win;
103 unsigned long ret;
104
105 if (reg < 16)
106 return (!reg ? 0 : regs->u_regs[reg]);
107
108
109 win = (struct reg_window32 __user *) regs->u_regs[UREG_FP];
110
111 if ((unsigned long)win & 3)
112 return -1;
113
114 if (get_user(ret, &win->locals[reg - 16]))
115 return -1;
116
117 return ret;
118}
119
120static inline unsigned long *fetch_reg_addr(unsigned int reg, struct pt_regs *regs)
121{
122 struct reg_window32 *win;
123
124 if(reg < 16)
125 return ®s->u_regs[reg];
126 win = (struct reg_window32 *) regs->u_regs[UREG_FP];
127 return &win->locals[reg - 16];
128}
129
130static unsigned long compute_effective_address(struct pt_regs *regs,
131 unsigned int insn)
132{
133 unsigned int rs1 = (insn >> 14) & 0x1f;
134 unsigned int rs2 = insn & 0x1f;
135 unsigned int rd = (insn >> 25) & 0x1f;
136
137 if(insn & 0x2000) {
138 maybe_flush_windows(rs1, 0, rd);
139 return (fetch_reg(rs1, regs) + sign_extend_imm13(insn));
140 } else {
141 maybe_flush_windows(rs1, rs2, rd);
142 return (fetch_reg(rs1, regs) + fetch_reg(rs2, regs));
143 }
144}
145
146unsigned long safe_compute_effective_address(struct pt_regs *regs,
147 unsigned int insn)
148{
149 unsigned int rs1 = (insn >> 14) & 0x1f;
150 unsigned int rs2 = insn & 0x1f;
151 unsigned int rd = (insn >> 25) & 0x1f;
152
153 if(insn & 0x2000) {
154 maybe_flush_windows(rs1, 0, rd);
155 return (safe_fetch_reg(rs1, regs) + sign_extend_imm13(insn));
156 } else {
157 maybe_flush_windows(rs1, rs2, rd);
158 return (safe_fetch_reg(rs1, regs) + safe_fetch_reg(rs2, regs));
159 }
160}
161
162
163static void unaligned_panic(char *str)
164{
165 panic(str);
166}
167
168
169extern int do_int_load(unsigned long *dest_reg, int size,
170 unsigned long *saddr, int is_signed);
171extern int __do_int_store(unsigned long *dst_addr, int size,
172 unsigned long *src_val);
173
174static int do_int_store(int reg_num, int size, unsigned long *dst_addr,
175 struct pt_regs *regs)
176{
177 unsigned long zero[2] = { 0, 0 };
178 unsigned long *src_val;
179
180 if (reg_num)
181 src_val = fetch_reg_addr(reg_num, regs);
182 else {
183 src_val = &zero[0];
184 if (size == 8)
185 zero[1] = fetch_reg(1, regs);
186 }
187 return __do_int_store(dst_addr, size, src_val);
188}
189
190extern void smp_capture(void);
191extern void smp_release(void);
192
193static inline void advance(struct pt_regs *regs)
194{
195 regs->pc = regs->npc;
196 regs->npc += 4;
197}
198
199static inline int floating_point_load_or_store_p(unsigned int insn)
200{
201 return (insn >> 24) & 1;
202}
203
204static inline int ok_for_kernel(unsigned int insn)
205{
206 return !floating_point_load_or_store_p(insn);
207}
208
209static void kernel_mna_trap_fault(struct pt_regs *regs, unsigned int insn)
210{
211 unsigned long g2 = regs->u_regs [UREG_G2];
212 unsigned long fixup = search_extables_range(regs->pc, &g2);
213
214 if (!fixup) {
215 unsigned long address = compute_effective_address(regs, insn);
216 if(address < PAGE_SIZE) {
217 printk(KERN_ALERT "Unable to handle kernel NULL pointer dereference in mna handler");
218 } else
219 printk(KERN_ALERT "Unable to handle kernel paging request in mna handler");
220 printk(KERN_ALERT " at virtual address %08lx\n",address);
221 printk(KERN_ALERT "current->{mm,active_mm}->context = %08lx\n",
222 (current->mm ? current->mm->context :
223 current->active_mm->context));
224 printk(KERN_ALERT "current->{mm,active_mm}->pgd = %08lx\n",
225 (current->mm ? (unsigned long) current->mm->pgd :
226 (unsigned long) current->active_mm->pgd));
227 die_if_kernel("Oops", regs);
228
229 }
230 regs->pc = fixup;
231 regs->npc = regs->pc + 4;
232 regs->u_regs [UREG_G2] = g2;
233}
234
235asmlinkage void kernel_unaligned_trap(struct pt_regs *regs, unsigned int insn)
236{
237 enum direction dir = decode_direction(insn);
238 int size = decode_access_size(insn);
239
240 if(!ok_for_kernel(insn) || dir == both) {
241 printk("Unsupported unaligned load/store trap for kernel at <%08lx>.\n",
242 regs->pc);
243 unaligned_panic("Wheee. Kernel does fpu/atomic unaligned load/store.");
244 } else {
245 unsigned long addr = compute_effective_address(regs, insn);
246 int err;
247
248 perf_sw_event(PERF_COUNT_SW_ALIGNMENT_FAULTS, 1, regs, addr);
249 switch (dir) {
250 case load:
251 err = do_int_load(fetch_reg_addr(((insn>>25)&0x1f),
252 regs),
253 size, (unsigned long *) addr,
254 decode_signedness(insn));
255 break;
256
257 case store:
258 err = do_int_store(((insn>>25)&0x1f), size,
259 (unsigned long *) addr, regs);
260 break;
261 default:
262 panic("Impossible kernel unaligned trap.");
263
264 }
265 if (err)
266 kernel_mna_trap_fault(regs, insn);
267 else
268 advance(regs);
269 }
270}
271
272static inline int ok_for_user(struct pt_regs *regs, unsigned int insn,
273 enum direction dir)
274{
275 unsigned int reg;
276 int check = (dir == load) ? VERIFY_READ : VERIFY_WRITE;
277 int size = ((insn >> 19) & 3) == 3 ? 8 : 4;
278
279 if ((regs->pc | regs->npc) & 3)
280 return 0;
281
282
283#define WINREG_ADDR(regnum) \
284 ((void __user *)(((unsigned long *)regs->u_regs[UREG_FP])+(regnum)))
285
286 reg = (insn >> 25) & 0x1f;
287 if (reg >= 16) {
288 if (!access_ok(check, WINREG_ADDR(reg - 16), size))
289 return -EFAULT;
290 }
291 reg = (insn >> 14) & 0x1f;
292 if (reg >= 16) {
293 if (!access_ok(check, WINREG_ADDR(reg - 16), size))
294 return -EFAULT;
295 }
296 if (!(insn & 0x2000)) {
297 reg = (insn & 0x1f);
298 if (reg >= 16) {
299 if (!access_ok(check, WINREG_ADDR(reg - 16), size))
300 return -EFAULT;
301 }
302 }
303#undef WINREG_ADDR
304 return 0;
305}
306
307static void user_mna_trap_fault(struct pt_regs *regs, unsigned int insn)
308{
309 siginfo_t info;
310
311 info.si_signo = SIGBUS;
312 info.si_errno = 0;
313 info.si_code = BUS_ADRALN;
314 info.si_addr = (void __user *)safe_compute_effective_address(regs, insn);
315 info.si_trapno = 0;
316 send_sig_info(SIGBUS, &info, current);
317}
318
319asmlinkage void user_unaligned_trap(struct pt_regs *regs, unsigned int insn)
320{
321 enum direction dir;
322
323 if(!(current->thread.flags & SPARC_FLAG_UNALIGNED) ||
324 (((insn >> 30) & 3) != 3))
325 goto kill_user;
326 dir = decode_direction(insn);
327 if(!ok_for_user(regs, insn, dir)) {
328 goto kill_user;
329 } else {
330 int err, size = decode_access_size(insn);
331 unsigned long addr;
332
333 if(floating_point_load_or_store_p(insn)) {
334 printk("User FPU load/store unaligned unsupported.\n");
335 goto kill_user;
336 }
337
338 addr = compute_effective_address(regs, insn);
339 perf_sw_event(PERF_COUNT_SW_ALIGNMENT_FAULTS, 1, regs, addr);
340 switch(dir) {
341 case load:
342 err = do_int_load(fetch_reg_addr(((insn>>25)&0x1f),
343 regs),
344 size, (unsigned long *) addr,
345 decode_signedness(insn));
346 break;
347
348 case store:
349 err = do_int_store(((insn>>25)&0x1f), size,
350 (unsigned long *) addr, regs);
351 break;
352
353 case both:
354
355
356
357
358 printk("Unaligned SWAP unsupported.\n");
359 err = -EFAULT;
360 break;
361
362 default:
363 unaligned_panic("Impossible user unaligned trap.");
364 goto out;
365 }
366 if (err)
367 goto kill_user;
368 else
369 advance(regs);
370 goto out;
371 }
372
373kill_user:
374 user_mna_trap_fault(regs, insn);
375out:
376 ;
377}
378
