1 // SPDX-License-Identifier: GPL-2.0
2 // Copyright (C) 2018 Hangzhou C-SKY Microsystems co.,ltd.
3
4 #include <linux/audit.h>
5 #include <linux/elf.h>
6 #include <linux/errno.h>
7 #include <linux/kernel.h>
8 #include <linux/mm.h>
9 #include <linux/ptrace.h>
10 #include <linux/regset.h>
11 #include <linux/sched.h>
12 #include <linux/sched/task_stack.h>
13 #include <linux/signal.h>
14 #include <linux/smp.h>
15 #include <linux/tracehook.h>
16 #include <linux/uaccess.h>
17 #include <linux/user.h>
18
19 #include <asm/thread_info.h>
20 #include <asm/page.h>
21 #include <asm/processor.h>
22 #include <asm/asm-offsets.h>
23
24 #include <abi/regdef.h>
25
26 #define CREATE_TRACE_POINTS
27 #include <trace/events/syscalls.h>
28
29 /* sets the trace bits. */
30 #define TRACE_MODE_SI (1 << 14)
31 #define TRACE_MODE_RUN 0
32 #define TRACE_MODE_MASK ~(0x3 << 14)
33
34 /*
35 * Make sure the single step bit is not set.
36 */
singlestep_disable(struct task_struct * tsk)37 static void singlestep_disable(struct task_struct *tsk)
38 {
39 struct pt_regs *regs;
40
41 regs = task_pt_regs(tsk);
42 regs->sr = (regs->sr & TRACE_MODE_MASK) | TRACE_MODE_RUN;
43
44 /* Enable irq */
45 regs->sr |= BIT(6);
46 }
47
singlestep_enable(struct task_struct * tsk)48 static void singlestep_enable(struct task_struct *tsk)
49 {
50 struct pt_regs *regs;
51
52 regs = task_pt_regs(tsk);
53 regs->sr = (regs->sr & TRACE_MODE_MASK) | TRACE_MODE_SI;
54
55 /* Disable irq */
56 regs->sr &= ~BIT(6);
57 }
58
59 /*
60 * Make sure the single step bit is set.
61 */
user_enable_single_step(struct task_struct * child)62 void user_enable_single_step(struct task_struct *child)
63 {
64 singlestep_enable(child);
65 }
66
user_disable_single_step(struct task_struct * child)67 void user_disable_single_step(struct task_struct *child)
68 {
69 singlestep_disable(child);
70 }
71
72 enum csky_regset {
73 REGSET_GPR,
74 REGSET_FPR,
75 };
76
gpr_get(struct task_struct * target,const struct user_regset * regset,struct membuf to)77 static int gpr_get(struct task_struct *target,
78 const struct user_regset *regset,
79 struct membuf to)
80 {
81 struct pt_regs *regs = task_pt_regs(target);
82
83 /* Abiv1 regs->tls is fake and we need sync here. */
84 regs->tls = task_thread_info(target)->tp_value;
85
86 return membuf_write(&to, regs, sizeof(*regs));
87 }
88
gpr_set(struct task_struct * target,const struct user_regset * regset,unsigned int pos,unsigned int count,const void * kbuf,const void __user * ubuf)89 static int gpr_set(struct task_struct *target,
90 const struct user_regset *regset,
91 unsigned int pos, unsigned int count,
92 const void *kbuf, const void __user *ubuf)
93 {
94 int ret;
95 struct pt_regs regs;
96
97 ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, ®s, 0, -1);
98 if (ret)
99 return ret;
100
101 /* BIT(0) of regs.sr is Condition Code/Carry bit */
102 regs.sr = (regs.sr & BIT(0)) | (task_pt_regs(target)->sr & ~BIT(0));
103 #ifdef CONFIG_CPU_HAS_HILO
104 regs.dcsr = task_pt_regs(target)->dcsr;
105 #endif
106 task_thread_info(target)->tp_value = regs.tls;
107
108 *task_pt_regs(target) = regs;
109
110 return 0;
111 }
112
fpr_get(struct task_struct * target,const struct user_regset * regset,struct membuf to)113 static int fpr_get(struct task_struct *target,
114 const struct user_regset *regset,
115 struct membuf to)
116 {
117 struct user_fp *regs = (struct user_fp *)&target->thread.user_fp;
118
119 #if defined(CONFIG_CPU_HAS_FPUV2) && !defined(CONFIG_CPU_HAS_VDSP)
120 int i;
121 struct user_fp tmp = *regs;
122
123 for (i = 0; i < 16; i++) {
124 tmp.vr[i*4] = regs->vr[i*2];
125 tmp.vr[i*4 + 1] = regs->vr[i*2 + 1];
126 }
127
128 for (i = 0; i < 32; i++)
129 tmp.vr[64 + i] = regs->vr[32 + i];
130
131 return membuf_write(&to, &tmp, sizeof(tmp));
132 #else
133 return membuf_write(&to, regs, sizeof(*regs));
134 #endif
135 }
136
fpr_set(struct task_struct * target,const struct user_regset * regset,unsigned int pos,unsigned int count,const void * kbuf,const void __user * ubuf)137 static int fpr_set(struct task_struct *target,
138 const struct user_regset *regset,
139 unsigned int pos, unsigned int count,
140 const void *kbuf, const void __user *ubuf)
141 {
142 int ret;
143 struct user_fp *regs = (struct user_fp *)&target->thread.user_fp;
144
145 #if defined(CONFIG_CPU_HAS_FPUV2) && !defined(CONFIG_CPU_HAS_VDSP)
146 int i;
147 struct user_fp tmp;
148
149 ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, &tmp, 0, -1);
150
151 *regs = tmp;
152
153 for (i = 0; i < 16; i++) {
154 regs->vr[i*2] = tmp.vr[i*4];
155 regs->vr[i*2 + 1] = tmp.vr[i*4 + 1];
156 }
157
158 for (i = 0; i < 32; i++)
159 regs->vr[32 + i] = tmp.vr[64 + i];
160 #else
161 ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, regs, 0, -1);
162 #endif
163
164 return ret;
165 }
166
167 static const struct user_regset csky_regsets[] = {
168 [REGSET_GPR] = {
169 .core_note_type = NT_PRSTATUS,
170 .n = sizeof(struct pt_regs) / sizeof(u32),
171 .size = sizeof(u32),
172 .align = sizeof(u32),
173 .regset_get = gpr_get,
174 .set = gpr_set,
175 },
176 [REGSET_FPR] = {
177 .core_note_type = NT_PRFPREG,
178 .n = sizeof(struct user_fp) / sizeof(u32),
179 .size = sizeof(u32),
180 .align = sizeof(u32),
181 .regset_get = fpr_get,
182 .set = fpr_set,
183 },
184 };
185
186 static const struct user_regset_view user_csky_view = {
187 .name = "csky",
188 .e_machine = ELF_ARCH,
189 .regsets = csky_regsets,
190 .n = ARRAY_SIZE(csky_regsets),
191 };
192
task_user_regset_view(struct task_struct * task)193 const struct user_regset_view *task_user_regset_view(struct task_struct *task)
194 {
195 return &user_csky_view;
196 }
197
198 struct pt_regs_offset {
199 const char *name;
200 int offset;
201 };
202
203 #define REG_OFFSET_NAME(r) {.name = #r, .offset = offsetof(struct pt_regs, r)}
204 #define REG_OFFSET_END {.name = NULL, .offset = 0}
205
206 static const struct pt_regs_offset regoffset_table[] = {
207 REG_OFFSET_NAME(tls),
208 REG_OFFSET_NAME(lr),
209 REG_OFFSET_NAME(pc),
210 REG_OFFSET_NAME(sr),
211 REG_OFFSET_NAME(usp),
212 REG_OFFSET_NAME(orig_a0),
213 REG_OFFSET_NAME(a0),
214 REG_OFFSET_NAME(a1),
215 REG_OFFSET_NAME(a2),
216 REG_OFFSET_NAME(a3),
217 REG_OFFSET_NAME(regs[0]),
218 REG_OFFSET_NAME(regs[1]),
219 REG_OFFSET_NAME(regs[2]),
220 REG_OFFSET_NAME(regs[3]),
221 REG_OFFSET_NAME(regs[4]),
222 REG_OFFSET_NAME(regs[5]),
223 REG_OFFSET_NAME(regs[6]),
224 REG_OFFSET_NAME(regs[7]),
225 REG_OFFSET_NAME(regs[8]),
226 REG_OFFSET_NAME(regs[9]),
227 #if defined(__CSKYABIV2__)
228 REG_OFFSET_NAME(exregs[0]),
229 REG_OFFSET_NAME(exregs[1]),
230 REG_OFFSET_NAME(exregs[2]),
231 REG_OFFSET_NAME(exregs[3]),
232 REG_OFFSET_NAME(exregs[4]),
233 REG_OFFSET_NAME(exregs[5]),
234 REG_OFFSET_NAME(exregs[6]),
235 REG_OFFSET_NAME(exregs[7]),
236 REG_OFFSET_NAME(exregs[8]),
237 REG_OFFSET_NAME(exregs[9]),
238 REG_OFFSET_NAME(exregs[10]),
239 REG_OFFSET_NAME(exregs[11]),
240 REG_OFFSET_NAME(exregs[12]),
241 REG_OFFSET_NAME(exregs[13]),
242 REG_OFFSET_NAME(exregs[14]),
243 REG_OFFSET_NAME(rhi),
244 REG_OFFSET_NAME(rlo),
245 REG_OFFSET_NAME(dcsr),
246 #endif
247 REG_OFFSET_END,
248 };
249
250 /**
251 * regs_query_register_offset() - query register offset from its name
252 * @name: the name of a register
253 *
254 * regs_query_register_offset() returns the offset of a register in struct
255 * pt_regs from its name. If the name is invalid, this returns -EINVAL;
256 */
regs_query_register_offset(const char * name)257 int regs_query_register_offset(const char *name)
258 {
259 const struct pt_regs_offset *roff;
260
261 for (roff = regoffset_table; roff->name != NULL; roff++)
262 if (!strcmp(roff->name, name))
263 return roff->offset;
264 return -EINVAL;
265 }
266
267 /**
268 * regs_within_kernel_stack() - check the address in the stack
269 * @regs: pt_regs which contains kernel stack pointer.
270 * @addr: address which is checked.
271 *
272 * regs_within_kernel_stack() checks @addr is within the kernel stack page(s).
273 * If @addr is within the kernel stack, it returns true. If not, returns false.
274 */
regs_within_kernel_stack(struct pt_regs * regs,unsigned long addr)275 static bool regs_within_kernel_stack(struct pt_regs *regs, unsigned long addr)
276 {
277 return (addr & ~(THREAD_SIZE - 1)) ==
278 (kernel_stack_pointer(regs) & ~(THREAD_SIZE - 1));
279 }
280
281 /**
282 * regs_get_kernel_stack_nth() - get Nth entry of the stack
283 * @regs: pt_regs which contains kernel stack pointer.
284 * @n: stack entry number.
285 *
286 * regs_get_kernel_stack_nth() returns @n th entry of the kernel stack which
287 * is specified by @regs. If the @n th entry is NOT in the kernel stack,
288 * this returns 0.
289 */
regs_get_kernel_stack_nth(struct pt_regs * regs,unsigned int n)290 unsigned long regs_get_kernel_stack_nth(struct pt_regs *regs, unsigned int n)
291 {
292 unsigned long *addr = (unsigned long *)kernel_stack_pointer(regs);
293
294 addr += n;
295 if (regs_within_kernel_stack(regs, (unsigned long)addr))
296 return *addr;
297 else
298 return 0;
299 }
300
ptrace_disable(struct task_struct * child)301 void ptrace_disable(struct task_struct *child)
302 {
303 singlestep_disable(child);
304 }
305
arch_ptrace(struct task_struct * child,long request,unsigned long addr,unsigned long data)306 long arch_ptrace(struct task_struct *child, long request,
307 unsigned long addr, unsigned long data)
308 {
309 long ret = -EIO;
310
311 switch (request) {
312 default:
313 ret = ptrace_request(child, request, addr, data);
314 break;
315 }
316
317 return ret;
318 }
319
syscall_trace_enter(struct pt_regs * regs)320 asmlinkage int syscall_trace_enter(struct pt_regs *regs)
321 {
322 if (test_thread_flag(TIF_SYSCALL_TRACE))
323 if (tracehook_report_syscall_entry(regs))
324 return -1;
325
326 if (secure_computing() == -1)
327 return -1;
328
329 if (test_thread_flag(TIF_SYSCALL_TRACEPOINT))
330 trace_sys_enter(regs, syscall_get_nr(current, regs));
331
332 audit_syscall_entry(regs_syscallid(regs), regs->a0, regs->a1, regs->a2, regs->a3);
333 return 0;
334 }
335
syscall_trace_exit(struct pt_regs * regs)336 asmlinkage void syscall_trace_exit(struct pt_regs *regs)
337 {
338 audit_syscall_exit(regs);
339
340 if (test_thread_flag(TIF_SYSCALL_TRACE))
341 tracehook_report_syscall_exit(regs, 0);
342
343 if (test_thread_flag(TIF_SYSCALL_TRACEPOINT))
344 trace_sys_exit(regs, syscall_get_return_value(current, regs));
345 }
346
show_regs(struct pt_regs * fp)347 void show_regs(struct pt_regs *fp)
348 {
349 pr_info("\nCURRENT PROCESS:\n\n");
350 pr_info("COMM=%s PID=%d\n", current->comm, current->pid);
351
352 if (current->mm) {
353 pr_info("TEXT=%08x-%08x DATA=%08x-%08x BSS=%08x-%08x\n",
354 (int) current->mm->start_code,
355 (int) current->mm->end_code,
356 (int) current->mm->start_data,
357 (int) current->mm->end_data,
358 (int) current->mm->end_data,
359 (int) current->mm->brk);
360 pr_info("USER-STACK=%08x KERNEL-STACK=%08x\n\n",
361 (int) current->mm->start_stack,
362 (int) (((unsigned long) current) + 2 * PAGE_SIZE));
363 }
364
365 pr_info("PC: 0x%08lx (%pS)\n", (long)fp->pc, (void *)fp->pc);
366 pr_info("LR: 0x%08lx (%pS)\n", (long)fp->lr, (void *)fp->lr);
367 pr_info("SP: 0x%08lx\n", (long)fp);
368 pr_info("orig_a0: 0x%08lx\n", fp->orig_a0);
369 pr_info("PSR: 0x%08lx\n", (long)fp->sr);
370
371 pr_info(" a0: 0x%08lx a1: 0x%08lx a2: 0x%08lx a3: 0x%08lx\n",
372 fp->a0, fp->a1, fp->a2, fp->a3);
373 #if defined(__CSKYABIV2__)
374 pr_info(" r4: 0x%08lx r5: 0x%08lx r6: 0x%08lx r7: 0x%08lx\n",
375 fp->regs[0], fp->regs[1], fp->regs[2], fp->regs[3]);
376 pr_info(" r8: 0x%08lx r9: 0x%08lx r10: 0x%08lx r11: 0x%08lx\n",
377 fp->regs[4], fp->regs[5], fp->regs[6], fp->regs[7]);
378 pr_info("r12: 0x%08lx r13: 0x%08lx r15: 0x%08lx\n",
379 fp->regs[8], fp->regs[9], fp->lr);
380 pr_info("r16: 0x%08lx r17: 0x%08lx r18: 0x%08lx r19: 0x%08lx\n",
381 fp->exregs[0], fp->exregs[1], fp->exregs[2], fp->exregs[3]);
382 pr_info("r20: 0x%08lx r21: 0x%08lx r22: 0x%08lx r23: 0x%08lx\n",
383 fp->exregs[4], fp->exregs[5], fp->exregs[6], fp->exregs[7]);
384 pr_info("r24: 0x%08lx r25: 0x%08lx r26: 0x%08lx r27: 0x%08lx\n",
385 fp->exregs[8], fp->exregs[9], fp->exregs[10], fp->exregs[11]);
386 pr_info("r28: 0x%08lx r29: 0x%08lx r30: 0x%08lx tls: 0x%08lx\n",
387 fp->exregs[12], fp->exregs[13], fp->exregs[14], fp->tls);
388 pr_info(" hi: 0x%08lx lo: 0x%08lx\n",
389 fp->rhi, fp->rlo);
390 #else
391 pr_info(" r6: 0x%08lx r7: 0x%08lx r8: 0x%08lx r9: 0x%08lx\n",
392 fp->regs[0], fp->regs[1], fp->regs[2], fp->regs[3]);
393 pr_info("r10: 0x%08lx r11: 0x%08lx r12: 0x%08lx r13: 0x%08lx\n",
394 fp->regs[4], fp->regs[5], fp->regs[6], fp->regs[7]);
395 pr_info("r14: 0x%08lx r1: 0x%08lx\n",
396 fp->regs[8], fp->regs[9]);
397 #endif
398
399 return;
400 }
401