arch/arc/kernel/ptrace.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * Copyright (C) 2004, 2007-2010, 2011-2012 Synopsys, Inc. (www.synopsys.com)
   4  */
   5
   6 #include <linux/ptrace.h>
   7 #include <linux/tracehook.h>
   8 #include <linux/sched/task_stack.h>
   9 #include <linux/regset.h>
  10 #include <linux/unistd.h>
  11 #include <linux/elf.h>
  12
  13 static struct callee_regs *task_callee_regs(struct task_struct *tsk)
  14 {
  15         struct callee_regs *tmp = (struct callee_regs *)tsk->thread.callee_reg;
  16         return tmp;
  17 }
  18
  19 static int genregs_get(struct task_struct *target,
  20                        const struct user_regset *regset,
  21                        struct membuf to)
  22 {
  23         const struct pt_regs *ptregs = task_pt_regs(target);
  24         const struct callee_regs *cregs = task_callee_regs(target);
  25         unsigned int stop_pc_val;
  26
  27         membuf_zero(&to, 4);    // pad
  28         membuf_store(&to, ptregs->bta);
  29         membuf_store(&to, ptregs->lp_start);
  30         membuf_store(&to, ptregs->lp_end);
  31         membuf_store(&to, ptregs->lp_count);
  32         membuf_store(&to, ptregs->status32);
  33         membuf_store(&to, ptregs->ret);
  34         membuf_store(&to, ptregs->blink);
  35         membuf_store(&to, ptregs->fp);
  36         membuf_store(&to, ptregs->r26); // gp
  37         membuf_store(&to, ptregs->r12);
  38         membuf_store(&to, ptregs->r11);
  39         membuf_store(&to, ptregs->r10);
  40         membuf_store(&to, ptregs->r9);
  41         membuf_store(&to, ptregs->r8);
  42         membuf_store(&to, ptregs->r7);
  43         membuf_store(&to, ptregs->r6);
  44         membuf_store(&to, ptregs->r5);
  45         membuf_store(&to, ptregs->r4);
  46         membuf_store(&to, ptregs->r3);
  47         membuf_store(&to, ptregs->r2);
  48         membuf_store(&to, ptregs->r1);
  49         membuf_store(&to, ptregs->r0);
  50         membuf_store(&to, ptregs->sp);
  51         membuf_zero(&to, 4);    // pad2
  52         membuf_store(&to, cregs->r25);
  53         membuf_store(&to, cregs->r24);
  54         membuf_store(&to, cregs->r23);
  55         membuf_store(&to, cregs->r22);
  56         membuf_store(&to, cregs->r21);
  57         membuf_store(&to, cregs->r20);
  58         membuf_store(&to, cregs->r19);
  59         membuf_store(&to, cregs->r18);
  60         membuf_store(&to, cregs->r17);
  61         membuf_store(&to, cregs->r16);
  62         membuf_store(&to, cregs->r15);
  63         membuf_store(&to, cregs->r14);
  64         membuf_store(&to, cregs->r13);
  65         membuf_store(&to, target->thread.fault_address); // efa
  66
  67         if (in_brkpt_trap(ptregs)) {
  68                 stop_pc_val = target->thread.fault_address;
  69                 pr_debug("\t\tstop_pc (brk-pt)\n");
  70         } else {
  71                 stop_pc_val = ptregs->ret;
  72                 pr_debug("\t\tstop_pc (others)\n");
  73         }
  74
  75         return membuf_store(&to, stop_pc_val); // stop_pc
  76 }
  77
  78 static int genregs_set(struct task_struct *target,
  79                        const struct user_regset *regset,
  80                        unsigned int pos, unsigned int count,
  81                        const void *kbuf, const void __user *ubuf)
  82 {
  83         const struct pt_regs *ptregs = task_pt_regs(target);
  84         const struct callee_regs *cregs = task_callee_regs(target);
  85         int ret = 0;
  86
  87 #define REG_IN_CHUNK(FIRST, NEXT, PTR)  \
  88         if (!ret)                       \
  89                 ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, \
  90                         (void *)(PTR), \
  91                         offsetof(struct user_regs_struct, FIRST), \
  92                         offsetof(struct user_regs_struct, NEXT));
  93
  94 #define REG_IN_ONE(LOC, PTR)            \
  95         if (!ret)                       \
  96                 ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, \
  97                         (void *)(PTR), \
  98                         offsetof(struct user_regs_struct, LOC), \
  99                         offsetof(struct user_regs_struct, LOC) + 4);
 100
 101 #define REG_IGNORE_ONE(LOC)             \
 102         if (!ret)                       \
 103                 ret = user_regset_copyin_ignore(&pos, &count, &kbuf, &ubuf, \
 104                         offsetof(struct user_regs_struct, LOC), \
 105                         offsetof(struct user_regs_struct, LOC) + 4);
 106
 107         REG_IGNORE_ONE(pad);
 108
 109         REG_IN_ONE(scratch.bta, &ptregs->bta);
 110         REG_IN_ONE(scratch.lp_start, &ptregs->lp_start);
 111         REG_IN_ONE(scratch.lp_end, &ptregs->lp_end);
 112         REG_IN_ONE(scratch.lp_count, &ptregs->lp_count);
 113
 114         REG_IGNORE_ONE(scratch.status32);
 115
 116         REG_IN_ONE(scratch.ret, &ptregs->ret);
 117         REG_IN_ONE(scratch.blink, &ptregs->blink);
 118         REG_IN_ONE(scratch.fp, &ptregs->fp);
 119         REG_IN_ONE(scratch.gp, &ptregs->r26);
 120         REG_IN_ONE(scratch.r12, &ptregs->r12);
 121         REG_IN_ONE(scratch.r11, &ptregs->r11);
 122         REG_IN_ONE(scratch.r10, &ptregs->r10);
 123         REG_IN_ONE(scratch.r9, &ptregs->r9);
 124         REG_IN_ONE(scratch.r8, &ptregs->r8);
 125         REG_IN_ONE(scratch.r7, &ptregs->r7);
 126         REG_IN_ONE(scratch.r6, &ptregs->r6);
 127         REG_IN_ONE(scratch.r5, &ptregs->r5);
 128         REG_IN_ONE(scratch.r4, &ptregs->r4);
 129         REG_IN_ONE(scratch.r3, &ptregs->r3);
 130         REG_IN_ONE(scratch.r2, &ptregs->r2);
 131         REG_IN_ONE(scratch.r1, &ptregs->r1);
 132         REG_IN_ONE(scratch.r0, &ptregs->r0);
 133         REG_IN_ONE(scratch.sp, &ptregs->sp);
 134
 135         REG_IGNORE_ONE(pad2);
 136
 137         REG_IN_ONE(callee.r25, &cregs->r25);
 138         REG_IN_ONE(callee.r24, &cregs->r24);
 139         REG_IN_ONE(callee.r23, &cregs->r23);
 140         REG_IN_ONE(callee.r22, &cregs->r22);
 141         REG_IN_ONE(callee.r21, &cregs->r21);
 142         REG_IN_ONE(callee.r20, &cregs->r20);
 143         REG_IN_ONE(callee.r19, &cregs->r19);
 144         REG_IN_ONE(callee.r18, &cregs->r18);
 145         REG_IN_ONE(callee.r17, &cregs->r17);
 146         REG_IN_ONE(callee.r16, &cregs->r16);
 147         REG_IN_ONE(callee.r15, &cregs->r15);
 148         REG_IN_ONE(callee.r14, &cregs->r14);
 149         REG_IN_ONE(callee.r13, &cregs->r13);
 150
 151         REG_IGNORE_ONE(efa);                    /* efa update invalid */
 152         REG_IGNORE_ONE(stop_pc);                /* PC updated via @ret */
 153
 154         return ret;
 155 }
 156
 157 #ifdef CONFIG_ISA_ARCV2
 158 static int arcv2regs_get(struct task_struct *target,
 159                        const struct user_regset *regset,
 160                        struct membuf to)
 161 {
 162         const struct pt_regs *regs = task_pt_regs(target);
 163
 164         if (IS_ENABLED(CONFIG_ARC_HAS_ACCL_REGS))
 165                 /*
 166                  * itemized copy not needed like above as layout of regs (r30,r58,r59)
 167                  * is exactly same in kernel (pt_regs) and userspace (user_regs_arcv2)
 168                  */
 169                 return membuf_write(&to, &regs->r30, sizeof(struct user_regs_arcv2));
 170
 171
 172         membuf_write(&to, &regs->r30, 4); /* r30 only */
 173         return membuf_zero(&to, sizeof(struct user_regs_arcv2) - 4);
 174 }
 175
 176 static int arcv2regs_set(struct task_struct *target,
 177                        const struct user_regset *regset,
 178                        unsigned int pos, unsigned int count,
 179                        const void *kbuf, const void __user *ubuf)
 180 {
 181         const struct pt_regs *regs = task_pt_regs(target);
 182         int ret, copy_sz;
 183
 184         if (IS_ENABLED(CONFIG_ARC_HAS_ACCL_REGS))
 185                 copy_sz = sizeof(struct user_regs_arcv2);
 186         else
 187                 copy_sz = 4;    /* r30 only */
 188
 189         ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, (void *)&regs->r30,
 190                                   0, copy_sz);
 191
 192         return ret;
 193 }
 194
 195 #endif
 196
 197 enum arc_getset {
 198         REGSET_CMN,
 199         REGSET_ARCV2,
 200 };
 201
 202 static const struct user_regset arc_regsets[] = {
 203         [REGSET_CMN] = {
 204                .core_note_type = NT_PRSTATUS,
 205                .n = ELF_NGREG,
 206                .size = sizeof(unsigned long),
 207                .align = sizeof(unsigned long),
 208                .regset_get = genregs_get,
 209                .set = genregs_set,
 210         },
 211 #ifdef CONFIG_ISA_ARCV2
 212         [REGSET_ARCV2] = {
 213                .core_note_type = NT_ARC_V2,
 214                .n = ELF_ARCV2REG,
 215                .size = sizeof(unsigned long),
 216                .align = sizeof(unsigned long),
 217                .regset_get = arcv2regs_get,
 218                .set = arcv2regs_set,
 219         },
 220 #endif
 221 };
 222
 223 static const struct user_regset_view user_arc_view = {
 224         .name           = "arc",
 225         .e_machine      = EM_ARC_INUSE,
 226         .regsets        = arc_regsets,
 227         .n              = ARRAY_SIZE(arc_regsets)
 228 };
 229
 230 const struct user_regset_view *task_user_regset_view(struct task_struct *task)
 231 {
 232         return &user_arc_view;
 233 }
 234
 235 void ptrace_disable(struct task_struct *child)
 236 {
 237 }
 238
 239 long arch_ptrace(struct task_struct *child, long request,
 240                  unsigned long addr, unsigned long data)
 241 {
 242         int ret = -EIO;
 243
 244         pr_debug("REQ=%ld: ADDR =0x%lx, DATA=0x%lx)\n", request, addr, data);
 245
 246         switch (request) {
 247         case PTRACE_GET_THREAD_AREA:
 248                 ret = put_user(task_thread_info(child)->thr_ptr,
 249                                (unsigned long __user *)data);
 250                 break;
 251         default:
 252                 ret = ptrace_request(child, request, addr, data);
 253                 break;
 254         }
 255
 256         return ret;
 257 }
 258
 259 asmlinkage int syscall_trace_entry(struct pt_regs *regs)
 260 {
 261         if (tracehook_report_syscall_entry(regs))
 262                 return ULONG_MAX;
 263
 264         return regs->r8;
 265 }
 266
 267 asmlinkage void syscall_trace_exit(struct pt_regs *regs)
 268 {
 269         tracehook_report_syscall_exit(regs, 0);
 270 }