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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
19#include <asm/setup.h>
20
21#include "kernel.h"
22
23enum direction {
24 load,
25 store,
26 both,
27 fpload,
28 fpstore,
29 invalid,
30};
31
32static inline enum direction decode_direction(unsigned int insn)
33{
34 unsigned long tmp = (insn >> 21) & 1;
35
36 if(!tmp)
37 return load;
38 else {
39 if(((insn>>19)&0x3f) == 15)
40 return both;
41 else
42 return store;
43 }
44}
45
46
47static inline int decode_access_size(unsigned int insn)
48{
49 insn = (insn >> 19) & 3;
50
51 if(!insn)
52 return 4;
53 else if(insn == 3)
54 return 8;
55 else if(insn == 2)
56 return 2;
57 else {
58 printk("Impossible unaligned trap. insn=%08x\n", insn);
59 die_if_kernel("Byte sized unaligned access?!?!", current->thread.kregs);
60 return 4;
61 }
62}
63
64
65static inline int decode_signedness(unsigned int insn)
66{
67 return (insn & 0x400000);
68}
69
70static inline void maybe_flush_windows(unsigned int rs1, unsigned int rs2,
71 unsigned int rd)
72{
73 if(rs2 >= 16 || rs1 >= 16 || rd >= 16) {
74
75 __asm__ __volatile__("save %sp, -0x40, %sp\n\t"
76 "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 "restore; restore; restore; restore;\n\t"
83 "restore; restore; restore;\n\t");
84 }
85}
86
87static inline int sign_extend_imm13(int imm)
88{
89 return imm << 19 >> 19;
90}
91
92static inline unsigned long fetch_reg(unsigned int reg, struct pt_regs *regs)
93{
94 struct reg_window32 *win;
95
96 if(reg < 16)
97 return (!reg ? 0 : regs->u_regs[reg]);
98
99
100 win = (struct reg_window32 *) regs->u_regs[UREG_FP];
101 return win->locals[reg - 16];
102}
103
104static inline unsigned long safe_fetch_reg(unsigned int reg, struct pt_regs *regs)
105{
106 struct reg_window32 __user *win;
107 unsigned long ret;
108
109 if (reg < 16)
110 return (!reg ? 0 : regs->u_regs[reg]);
111
112
113 win = (struct reg_window32 __user *) regs->u_regs[UREG_FP];
114
115 if ((unsigned long)win & 3)
116 return -1;
117
118 if (get_user(ret, &win->locals[reg - 16]))
119 return -1;
120
121 return ret;
122}
123
124static inline unsigned long *fetch_reg_addr(unsigned int reg, struct pt_regs *regs)
125{
126 struct reg_window32 *win;
127
128 if(reg < 16)
129 return ®s->u_regs[reg];
130 win = (struct reg_window32 *) regs->u_regs[UREG_FP];
131 return &win->locals[reg - 16];
132}
133
134static unsigned long compute_effective_address(struct pt_regs *regs,
135 unsigned int insn)
136{
137 unsigned int rs1 = (insn >> 14) & 0x1f;
138 unsigned int rs2 = insn & 0x1f;
139 unsigned int rd = (insn >> 25) & 0x1f;
140
141 if(insn & 0x2000) {
142 maybe_flush_windows(rs1, 0, rd);
143 return (fetch_reg(rs1, regs) + sign_extend_imm13(insn));
144 } else {
145 maybe_flush_windows(rs1, rs2, rd);
146 return (fetch_reg(rs1, regs) + fetch_reg(rs2, regs));
147 }
148}
149
150unsigned long safe_compute_effective_address(struct pt_regs *regs,
151 unsigned int insn)
152{
153 unsigned int rs1 = (insn >> 14) & 0x1f;
154 unsigned int rs2 = insn & 0x1f;
155 unsigned int rd = (insn >> 25) & 0x1f;
156
157 if(insn & 0x2000) {
158 maybe_flush_windows(rs1, 0, rd);
159 return (safe_fetch_reg(rs1, regs) + sign_extend_imm13(insn));
160 } else {
161 maybe_flush_windows(rs1, rs2, rd);
162 return (safe_fetch_reg(rs1, regs) + safe_fetch_reg(rs2, regs));
163 }
164}
165
166
167static void unaligned_panic(char *str)
168{
169 panic("%s", str);
170}
171
172
173extern int do_int_load(unsigned long *dest_reg, int size,
174 unsigned long *saddr, int is_signed);
175extern int __do_int_store(unsigned long *dst_addr, int size,
176 unsigned long *src_val);
177
178static int do_int_store(int reg_num, int size, unsigned long *dst_addr,
179 struct pt_regs *regs)
180{
181 unsigned long zero[2] = { 0, 0 };
182 unsigned long *src_val;
183
184 if (reg_num)
185 src_val = fetch_reg_addr(reg_num, regs);
186 else {
187 src_val = &zero[0];
188 if (size == 8)
189 zero[1] = fetch_reg(1, regs);
190 }
191 return __do_int_store(dst_addr, size, src_val);
192}
193
194extern void smp_capture(void);
195extern void smp_release(void);
196
197static inline void advance(struct pt_regs *regs)
198{
199 regs->pc = regs->npc;
200 regs->npc += 4;
201}
202
203static inline int floating_point_load_or_store_p(unsigned int insn)
204{
205 return (insn >> 24) & 1;
206}
207
208static inline int ok_for_kernel(unsigned int insn)
209{
210 return !floating_point_load_or_store_p(insn);
211}
212
213static void kernel_mna_trap_fault(struct pt_regs *regs, unsigned int insn)
214{
215 unsigned long g2 = regs->u_regs [UREG_G2];
216 unsigned long fixup = search_extables_range(regs->pc, &g2);
217
218 if (!fixup) {
219 unsigned long address = compute_effective_address(regs, insn);
220 if(address < PAGE_SIZE) {
221 printk(KERN_ALERT "Unable to handle kernel NULL pointer dereference in mna handler");
222 } else
223 printk(KERN_ALERT "Unable to handle kernel paging request in mna handler");
224 printk(KERN_ALERT " at virtual address %08lx\n",address);
225 printk(KERN_ALERT "current->{mm,active_mm}->context = %08lx\n",
226 (current->mm ? current->mm->context :
227 current->active_mm->context));
228 printk(KERN_ALERT "current->{mm,active_mm}->pgd = %08lx\n",
229 (current->mm ? (unsigned long) current->mm->pgd :
230 (unsigned long) current->active_mm->pgd));
231 die_if_kernel("Oops", regs);
232
233 }
234 regs->pc = fixup;
235 regs->npc = regs->pc + 4;
236 regs->u_regs [UREG_G2] = g2;
237}
238
239asmlinkage void kernel_unaligned_trap(struct pt_regs *regs, unsigned int insn)
240{
241 enum direction dir = decode_direction(insn);
242 int size = decode_access_size(insn);
243
244 if(!ok_for_kernel(insn) || dir == both) {
245 printk("Unsupported unaligned load/store trap for kernel at <%08lx>.\n",
246 regs->pc);
247 unaligned_panic("Wheee. Kernel does fpu/atomic unaligned load/store.");
248 } else {
249 unsigned long addr = compute_effective_address(regs, insn);
250 int err;
251
252 perf_sw_event(PERF_COUNT_SW_ALIGNMENT_FAULTS, 1, regs, addr);
253 switch (dir) {
254 case load:
255 err = do_int_load(fetch_reg_addr(((insn>>25)&0x1f),
256 regs),
257 size, (unsigned long *) addr,
258 decode_signedness(insn));
259 break;
260
261 case store:
262 err = do_int_store(((insn>>25)&0x1f), size,
263 (unsigned long *) addr, regs);
264 break;
265 default:
266 panic("Impossible kernel unaligned trap.");
267
268 }
269 if (err)
270 kernel_mna_trap_fault(regs, insn);
271 else
272 advance(regs);
273 }
274}
275
276static inline int ok_for_user(struct pt_regs *regs, unsigned int insn,
277 enum direction dir)
278{
279 unsigned int reg;
280 int check = (dir == load) ? VERIFY_READ : VERIFY_WRITE;
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(check, WINREG_ADDR(reg - 16), size))
293 return -EFAULT;
294 }
295 reg = (insn >> 14) & 0x1f;
296 if (reg >= 16) {
297 if (!access_ok(check, 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(check, 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 siginfo_t info;
314
315 info.si_signo = SIGBUS;
316 info.si_errno = 0;
317 info.si_code = BUS_ADRALN;
318 info.si_addr = (void __user *)safe_compute_effective_address(regs, insn);
319 info.si_trapno = 0;
320 send_sig_info(SIGBUS, &info, current);
321}
322
323asmlinkage void user_unaligned_trap(struct pt_regs *regs, unsigned int insn)
324{
325 enum direction dir;
326
327 if(!(current->thread.flags & SPARC_FLAG_UNALIGNED) ||
328 (((insn >> 30) & 3) != 3))
329 goto kill_user;
330 dir = decode_direction(insn);
331 if(!ok_for_user(regs, insn, dir)) {
332 goto kill_user;
333 } else {
334 int err, size = decode_access_size(insn);
335 unsigned long addr;
336
337 if(floating_point_load_or_store_p(insn)) {
338 printk("User FPU load/store unaligned unsupported.\n");
339 goto kill_user;
340 }
341
342 addr = compute_effective_address(regs, insn);
343 perf_sw_event(PERF_COUNT_SW_ALIGNMENT_FAULTS, 1, regs, addr);
344 switch(dir) {
345 case load:
346 err = do_int_load(fetch_reg_addr(((insn>>25)&0x1f),
347 regs),
348 size, (unsigned long *) addr,
349 decode_signedness(insn));
350 break;
351
352 case store:
353 err = do_int_store(((insn>>25)&0x1f), size,
354 (unsigned long *) addr, regs);
355 break;
356
357 case both:
358
359
360
361
362 printk("Unaligned SWAP unsupported.\n");
363 err = -EFAULT;
364 break;
365
366 default:
367 unaligned_panic("Impossible user unaligned trap.");
368 goto out;
369 }
370 if (err)
371 goto kill_user;
372 else
373 advance(regs);
374 goto out;
375 }
376
377kill_user:
378 user_mna_trap_fault(regs, insn);
379out:
380 ;
381}
382
