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