arch/arc/kernel/ptrace.c

   1 /*
   2  * Copyright (C) 2004, 2007-2010, 2011-2012 Synopsys, Inc. (www.synopsys.com)
   3  *
   4  * This program is free software; you can redistribute it and/or modify
   5  * it under the terms of the GNU General Public License version 2 as
   6  * published by the Free Software Foundation.
   7  */
   8
   9 #include <linux/ptrace.h>
  10 #include <linux/tracehook.h>
  11 #include <linux/sched/task_stack.h>
  12 #include <linux/regset.h>
  13 #include <linux/unistd.h>
  14 #include <linux/elf.h>
  15
  16 static struct callee_regs *task_callee_regs(struct task_struct *tsk)
  17 {
  18         struct callee_regs *tmp = (struct callee_regs *)tsk->thread.callee_reg;
  19         return tmp;
  20 }
  21
  22 static int genregs_get(struct task_struct *target,
  23                        const struct user_regset *regset,
  24                        unsigned int pos, unsigned int count,
  25                        void *kbuf, void __user *ubuf)
  26 {
  27         const struct pt_regs *ptregs = task_pt_regs(target);
  28         const struct callee_regs *cregs = task_callee_regs(target);
  29         int ret = 0;
  30         unsigned int stop_pc_val;
  31
  32 #define REG_O_CHUNK(START, END, PTR)    \
  33         if (!ret)       \
  34                 ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf, PTR, \
  35                         offsetof(struct user_regs_struct, START), \
  36                         offsetof(struct user_regs_struct, END));
  37
  38 #define REG_O_ONE(LOC, PTR)     \
  39         if (!ret)               \
  40                 ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf, PTR, \
  41                         offsetof(struct user_regs_struct, LOC), \
  42                         offsetof(struct user_regs_struct, LOC) + 4);
  43
  44 #define REG_O_ZERO(LOC)         \
  45         if (!ret)               \
  46                 ret = user_regset_copyout_zero(&pos, &count, &kbuf, &ubuf, \
  47                         offsetof(struct user_regs_struct, LOC), \
  48                         offsetof(struct user_regs_struct, LOC) + 4);
  49
  50         REG_O_ZERO(pad);
  51         REG_O_ONE(scratch.bta, &ptregs->bta);
  52         REG_O_ONE(scratch.lp_start, &ptregs->lp_start);
  53         REG_O_ONE(scratch.lp_end, &ptregs->lp_end);
  54         REG_O_ONE(scratch.lp_count, &ptregs->lp_count);
  55         REG_O_ONE(scratch.status32, &ptregs->status32);
  56         REG_O_ONE(scratch.ret, &ptregs->ret);
  57         REG_O_ONE(scratch.blink, &ptregs->blink);
  58         REG_O_ONE(scratch.fp, &ptregs->fp);
  59         REG_O_ONE(scratch.gp, &ptregs->r26);
  60         REG_O_ONE(scratch.r12, &ptregs->r12);
  61         REG_O_ONE(scratch.r11, &ptregs->r11);
  62         REG_O_ONE(scratch.r10, &ptregs->r10);
  63         REG_O_ONE(scratch.r9, &ptregs->r9);
  64         REG_O_ONE(scratch.r8, &ptregs->r8);
  65         REG_O_ONE(scratch.r7, &ptregs->r7);
  66         REG_O_ONE(scratch.r6, &ptregs->r6);
  67         REG_O_ONE(scratch.r5, &ptregs->r5);
  68         REG_O_ONE(scratch.r4, &ptregs->r4);
  69         REG_O_ONE(scratch.r3, &ptregs->r3);
  70         REG_O_ONE(scratch.r2, &ptregs->r2);
  71         REG_O_ONE(scratch.r1, &ptregs->r1);
  72         REG_O_ONE(scratch.r0, &ptregs->r0);
  73         REG_O_ONE(scratch.sp, &ptregs->sp);
  74
  75         REG_O_ZERO(pad2);
  76
  77         REG_O_ONE(callee.r25, &cregs->r25);
  78         REG_O_ONE(callee.r24, &cregs->r24);
  79         REG_O_ONE(callee.r23, &cregs->r23);
  80         REG_O_ONE(callee.r22, &cregs->r22);
  81         REG_O_ONE(callee.r21, &cregs->r21);
  82         REG_O_ONE(callee.r20, &cregs->r20);
  83         REG_O_ONE(callee.r19, &cregs->r19);
  84         REG_O_ONE(callee.r18, &cregs->r18);
  85         REG_O_ONE(callee.r17, &cregs->r17);
  86         REG_O_ONE(callee.r16, &cregs->r16);
  87         REG_O_ONE(callee.r15, &cregs->r15);
  88         REG_O_ONE(callee.r14, &cregs->r14);
  89         REG_O_ONE(callee.r13, &cregs->r13);
  90
  91         REG_O_ONE(efa, &target->thread.fault_address);
  92
  93         if (!ret) {
  94                 if (in_brkpt_trap(ptregs)) {
  95                         stop_pc_val = target->thread.fault_address;
  96                         pr_debug("\t\tstop_pc (brk-pt)\n");
  97                 } else {
  98                         stop_pc_val = ptregs->ret;
  99                         pr_debug("\t\tstop_pc (others)\n");
 100                 }
 101
 102                 REG_O_ONE(stop_pc, &stop_pc_val);
 103         }
 104
 105         return ret;
 106 }
 107
 108 static int genregs_set(struct task_struct *target,
 109                        const struct user_regset *regset,
 110                        unsigned int pos, unsigned int count,
 111                        const void *kbuf, const void __user *ubuf)
 112 {
 113         const struct pt_regs *ptregs = task_pt_regs(target);
 114         const struct callee_regs *cregs = task_callee_regs(target);
 115         int ret = 0;
 116
 117 #define REG_IN_CHUNK(FIRST, NEXT, PTR)  \
 118         if (!ret)                       \
 119                 ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, \
 120                         (void *)(PTR), \
 121                         offsetof(struct user_regs_struct, FIRST), \
 122                         offsetof(struct user_regs_struct, NEXT));
 123
 124 #define REG_IN_ONE(LOC, PTR)            \
 125         if (!ret)                       \
 126                 ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, \
 127                         (void *)(PTR), \
 128                         offsetof(struct user_regs_struct, LOC), \
 129                         offsetof(struct user_regs_struct, LOC) + 4);
 130
 131 #define REG_IGNORE_ONE(LOC)             \
 132         if (!ret)                       \
 133                 ret = user_regset_copyin_ignore(&pos, &count, &kbuf, &ubuf, \
 134                         offsetof(struct user_regs_struct, LOC), \
 135                         offsetof(struct user_regs_struct, LOC) + 4);
 136
 137         REG_IGNORE_ONE(pad);
 138
 139         REG_IN_ONE(scratch.bta, &ptregs->bta);
 140         REG_IN_ONE(scratch.lp_start, &ptregs->lp_start);
 141         REG_IN_ONE(scratch.lp_end, &ptregs->lp_end);
 142         REG_IN_ONE(scratch.lp_count, &ptregs->lp_count);
 143
 144         REG_IGNORE_ONE(scratch.status32);
 145
 146         REG_IN_ONE(scratch.ret, &ptregs->ret);
 147         REG_IN_ONE(scratch.blink, &ptregs->blink);
 148         REG_IN_ONE(scratch.fp, &ptregs->fp);
 149         REG_IN_ONE(scratch.gp, &ptregs->r26);
 150         REG_IN_ONE(scratch.r12, &ptregs->r12);
 151         REG_IN_ONE(scratch.r11, &ptregs->r11);
 152         REG_IN_ONE(scratch.r10, &ptregs->r10);
 153         REG_IN_ONE(scratch.r9, &ptregs->r9);
 154         REG_IN_ONE(scratch.r8, &ptregs->r8);
 155         REG_IN_ONE(scratch.r7, &ptregs->r7);
 156         REG_IN_ONE(scratch.r6, &ptregs->r6);
 157         REG_IN_ONE(scratch.r5, &ptregs->r5);
 158         REG_IN_ONE(scratch.r4, &ptregs->r4);
 159         REG_IN_ONE(scratch.r3, &ptregs->r3);
 160         REG_IN_ONE(scratch.r2, &ptregs->r2);
 161         REG_IN_ONE(scratch.r1, &ptregs->r1);
 162         REG_IN_ONE(scratch.r0, &ptregs->r0);
 163         REG_IN_ONE(scratch.sp, &ptregs->sp);
 164
 165         REG_IGNORE_ONE(pad2);
 166
 167         REG_IN_ONE(callee.r25, &cregs->r25);
 168         REG_IN_ONE(callee.r24, &cregs->r24);
 169         REG_IN_ONE(callee.r23, &cregs->r23);
 170         REG_IN_ONE(callee.r22, &cregs->r22);
 171         REG_IN_ONE(callee.r21, &cregs->r21);
 172         REG_IN_ONE(callee.r20, &cregs->r20);
 173         REG_IN_ONE(callee.r19, &cregs->r19);
 174         REG_IN_ONE(callee.r18, &cregs->r18);
 175         REG_IN_ONE(callee.r17, &cregs->r17);
 176         REG_IN_ONE(callee.r16, &cregs->r16);
 177         REG_IN_ONE(callee.r15, &cregs->r15);
 178         REG_IN_ONE(callee.r14, &cregs->r14);
 179         REG_IN_ONE(callee.r13, &cregs->r13);
 180
 181         REG_IGNORE_ONE(efa);                    /* efa update invalid */
 182         REG_IGNORE_ONE(stop_pc);                /* PC updated via @ret */
 183
 184         return ret;
 185 }
 186
 187 #ifdef CONFIG_ISA_ARCV2
 188 static int arcv2regs_get(struct task_struct *target,
 189                        const struct user_regset *regset,
 190                        unsigned int pos, unsigned int count,
 191                        void *kbuf, void __user *ubuf)
 192 {
 193         const struct pt_regs *regs = task_pt_regs(target);
 194         int ret, copy_sz;
 195
 196         if (IS_ENABLED(CONFIG_ARC_HAS_ACCL_REGS))
 197                 copy_sz = sizeof(struct user_regs_arcv2);
 198         else
 199                 copy_sz = 4;    /* r30 only */
 200
 201         /*
 202          * itemized copy not needed like above as layout of regs (r30,r58,r59)
 203          * is exactly same in kernel (pt_regs) and userspace (user_regs_arcv2)
 204          */
 205         ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf, &regs->r30,
 206                                   0, copy_sz);
 207
 208         return ret;
 209 }
 210
 211 static int arcv2regs_set(struct task_struct *target,
 212                        const struct user_regset *regset,
 213                        unsigned int pos, unsigned int count,
 214                        const void *kbuf, const void __user *ubuf)
 215 {
 216         const struct pt_regs *regs = task_pt_regs(target);
 217         int ret, copy_sz;
 218
 219         if (IS_ENABLED(CONFIG_ARC_HAS_ACCL_REGS))
 220                 copy_sz = sizeof(struct user_regs_arcv2);
 221         else
 222                 copy_sz = 4;    /* r30 only */
 223
 224         ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, (void *)&regs->r30,
 225                                   0, copy_sz);
 226
 227         return ret;
 228 }
 229
 230 #endif
 231
 232 enum arc_getset {
 233         REGSET_CMN,
 234         REGSET_ARCV2,
 235 };
 236
 237 static const struct user_regset arc_regsets[] = {
 238         [REGSET_CMN] = {
 239                .core_note_type = NT_PRSTATUS,
 240                .n = ELF_NGREG,
 241                .size = sizeof(unsigned long),
 242                .align = sizeof(unsigned long),
 243                .get = genregs_get,
 244                .set = genregs_set,
 245         },
 246 #ifdef CONFIG_ISA_ARCV2
 247         [REGSET_ARCV2] = {
 248                .core_note_type = NT_ARC_V2,
 249                .n = ELF_ARCV2REG,
 250                .size = sizeof(unsigned long),
 251                .align = sizeof(unsigned long),
 252                .get = arcv2regs_get,
 253                .set = arcv2regs_set,
 254         },
 255 #endif
 256 };
 257
 258 static const struct user_regset_view user_arc_view = {
 259         .name           = UTS_MACHINE,
 260         .e_machine      = EM_ARC_INUSE,
 261         .regsets        = arc_regsets,
 262         .n              = ARRAY_SIZE(arc_regsets)
 263 };
 264
 265 const struct user_regset_view *task_user_regset_view(struct task_struct *task)
 266 {
 267         return &user_arc_view;
 268 }
 269
 270 void ptrace_disable(struct task_struct *child)
 271 {
 272 }
 273
 274 long arch_ptrace(struct task_struct *child, long request,
 275                  unsigned long addr, unsigned long data)
 276 {
 277         int ret = -EIO;
 278
 279         pr_debug("REQ=%ld: ADDR =0x%lx, DATA=0x%lx)\n", request, addr, data);
 280
 281         switch (request) {
 282         case PTRACE_GET_THREAD_AREA:
 283                 ret = put_user(task_thread_info(child)->thr_ptr,
 284                                (unsigned long __user *)data);
 285                 break;
 286         default:
 287                 ret = ptrace_request(child, request, addr, data);
 288                 break;
 289         }
 290
 291         return ret;
 292 }
 293
 294 asmlinkage int syscall_trace_entry(struct pt_regs *regs)
 295 {
 296         if (tracehook_report_syscall_entry(regs))
 297                 return ULONG_MAX;
 298
 299         return regs->r8;
 300 }
 301
 302 asmlinkage void syscall_trace_exit(struct pt_regs *regs)
 303 {
 304         tracehook_report_syscall_exit(regs, 0);
 305 }