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/regset.h>
  12 #include <linux/unistd.h>
  13 #include <linux/elf.h>
  14
  15 static struct callee_regs *task_callee_regs(struct task_struct *tsk)
  16 {
  17         struct callee_regs *tmp = (struct callee_regs *)tsk->thread.callee_reg;
  18         return tmp;
  19 }
  20
  21 static int genregs_get(struct task_struct *target,
  22                        const struct user_regset *regset,
  23                        unsigned int pos, unsigned int count,
  24                        void *kbuf, void __user *ubuf)
  25 {
  26         const struct pt_regs *ptregs = task_pt_regs(target);
  27         const struct callee_regs *cregs = task_callee_regs(target);
  28         int ret = 0;
  29         unsigned int stop_pc_val;
  30
  31 #define REG_O_CHUNK(START, END, PTR)    \
  32         if (!ret)       \
  33                 ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf, PTR, \
  34                         offsetof(struct user_regs_struct, START), \
  35                         offsetof(struct user_regs_struct, END));
  36
  37 #define REG_O_ONE(LOC, PTR)     \
  38         if (!ret)               \
  39                 ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf, PTR, \
  40                         offsetof(struct user_regs_struct, LOC), \
  41                         offsetof(struct user_regs_struct, LOC) + 4);
  42
  43 #define REG_O_ZERO(LOC)         \
  44         if (!ret)               \
  45                 ret = user_regset_copyout_zero(&pos, &count, &kbuf, &ubuf, \
  46                         offsetof(struct user_regs_struct, LOC), \
  47                         offsetof(struct user_regs_struct, LOC) + 4);
  48
  49         REG_O_ZERO(pad);
  50         REG_O_CHUNK(scratch, callee, ptregs);
  51         REG_O_ZERO(pad2);
  52         REG_O_CHUNK(callee, efa, cregs);
  53         REG_O_CHUNK(efa, stop_pc, &target->thread.fault_address);
  54
  55         if (!ret) {
  56                 if (in_brkpt_trap(ptregs)) {
  57                         stop_pc_val = target->thread.fault_address;
  58                         pr_debug("\t\tstop_pc (brk-pt)\n");
  59                 } else {
  60                         stop_pc_val = ptregs->ret;
  61                         pr_debug("\t\tstop_pc (others)\n");
  62                 }
  63
  64                 REG_O_ONE(stop_pc, &stop_pc_val);
  65         }
  66
  67         return ret;
  68 }
  69
  70 static int genregs_set(struct task_struct *target,
  71                        const struct user_regset *regset,
  72                        unsigned int pos, unsigned int count,
  73                        const void *kbuf, const void __user *ubuf)
  74 {
  75         const struct pt_regs *ptregs = task_pt_regs(target);
  76         const struct callee_regs *cregs = task_callee_regs(target);
  77         int ret = 0;
  78
  79 #define REG_IN_CHUNK(FIRST, NEXT, PTR)  \
  80         if (!ret)                       \
  81                 ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, \
  82                         (void *)(PTR), \
  83                         offsetof(struct user_regs_struct, FIRST), \
  84                         offsetof(struct user_regs_struct, NEXT));
  85
  86 #define REG_IN_ONE(LOC, PTR)            \
  87         if (!ret)                       \
  88                 ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, \
  89                         (void *)(PTR), \
  90                         offsetof(struct user_regs_struct, LOC), \
  91                         offsetof(struct user_regs_struct, LOC) + 4);
  92
  93 #define REG_IGNORE_ONE(LOC)             \
  94         if (!ret)                       \
  95                 ret = user_regset_copyin_ignore(&pos, &count, &kbuf, &ubuf, \
  96                         offsetof(struct user_regs_struct, LOC), \
  97                         offsetof(struct user_regs_struct, LOC) + 4);
  98
  99         REG_IGNORE_ONE(pad);
 100         /* TBD: disallow updates to STATUS32 etc*/
 101         REG_IN_CHUNK(scratch, pad2, ptregs);    /* pt_regs[bta..sp] */
 102         REG_IGNORE_ONE(pad2);
 103         REG_IN_CHUNK(callee, efa, cregs);       /* callee_regs[r25..r13] */
 104         REG_IGNORE_ONE(efa);                    /* efa update invalid */
 105         REG_IGNORE_ONE(stop_pc);                        /* PC updated via @ret */
 106
 107         return ret;
 108 }
 109
 110 enum arc_getset {
 111         REGSET_GENERAL,
 112 };
 113
 114 static const struct user_regset arc_regsets[] = {
 115         [REGSET_GENERAL] = {
 116                .core_note_type = NT_PRSTATUS,
 117                .n = ELF_NGREG,
 118                .size = sizeof(unsigned long),
 119                .align = sizeof(unsigned long),
 120                .get = genregs_get,
 121                .set = genregs_set,
 122         }
 123 };
 124
 125 static const struct user_regset_view user_arc_view = {
 126         .name           = UTS_MACHINE,
 127         .e_machine      = EM_ARCOMPACT,
 128         .regsets        = arc_regsets,
 129         .n              = ARRAY_SIZE(arc_regsets)
 130 };
 131
 132 const struct user_regset_view *task_user_regset_view(struct task_struct *task)
 133 {
 134         return &user_arc_view;
 135 }
 136
 137 void ptrace_disable(struct task_struct *child)
 138 {
 139 }
 140
 141 long arch_ptrace(struct task_struct *child, long request,
 142                  unsigned long addr, unsigned long data)
 143 {
 144         int ret = -EIO;
 145
 146         pr_debug("REQ=%ld: ADDR =0x%lx, DATA=0x%lx)\n", request, addr, data);
 147
 148         switch (request) {
 149         default:
 150                 ret = ptrace_request(child, request, addr, data);
 151                 break;
 152         }
 153
 154         return ret;
 155 }
 156
 157 asmlinkage int syscall_trace_entry(struct pt_regs *regs)
 158 {
 159         if (tracehook_report_syscall_entry(regs))
 160                 return ULONG_MAX;
 161
 162         return regs->r8;
 163 }
 164
 165 asmlinkage void syscall_trace_exit(struct pt_regs *regs)
 166 {
 167         tracehook_report_syscall_exit(regs, 0);
 168 }