arch/nios2/kernel/ptrace.c

   1 /*
   2  * Copyright (C) 2014 Altera Corporation
   3  * Copyright (C) 2010 Tobias Klauser <tklauser@distanz.ch>
   4  *
   5  * This file is subject to the terms and conditions of the GNU General
   6  * Public License.  See the file COPYING in the main directory of this
   7  * archive for more details.
   8  */
   9
  10 #include <linux/elf.h>
  11 #include <linux/errno.h>
  12 #include <linux/kernel.h>
  13 #include <linux/mm.h>
  14 #include <linux/ptrace.h>
  15 #include <linux/regset.h>
  16 #include <linux/sched.h>
  17 #include <linux/sched/task_stack.h>
  18 #include <linux/tracehook.h>
  19 #include <linux/uaccess.h>
  20 #include <linux/user.h>
  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 *regs = task_pt_regs(target);
  28         const struct switch_stack *sw = (struct switch_stack *)regs - 1;
  29         int ret = 0;
  30
  31 #define REG_O_ZERO_RANGE(START, END)            \
  32         if (!ret)                                       \
  33                 ret = user_regset_copyout_zero(&pos, &count, &kbuf, &ubuf, \
  34                         START * 4, (END * 4) + 4);
  35
  36 #define REG_O_ONE(PTR, LOC)     \
  37         if (!ret)                       \
  38                 ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf, PTR, \
  39                         LOC * 4, (LOC * 4) + 4);
  40
  41 #define REG_O_RANGE(PTR, START, END)    \
  42         if (!ret)                               \
  43                 ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf, PTR, \
  44                         START * 4, (END * 4) + 4);
  45
  46         REG_O_ZERO_RANGE(PTR_R0, PTR_R0);
  47         REG_O_RANGE(&regs->r1, PTR_R1, PTR_R7);
  48         REG_O_RANGE(&regs->r8, PTR_R8, PTR_R15);
  49         REG_O_RANGE(sw, PTR_R16, PTR_R23);
  50         REG_O_ZERO_RANGE(PTR_R24, PTR_R25); /* et and bt */
  51         REG_O_ONE(&regs->gp, PTR_GP);
  52         REG_O_ONE(&regs->sp, PTR_SP);
  53         REG_O_ONE(&regs->fp, PTR_FP);
  54         REG_O_ONE(&regs->ea, PTR_EA);
  55         REG_O_ZERO_RANGE(PTR_BA, PTR_BA);
  56         REG_O_ONE(&regs->ra, PTR_RA);
  57         REG_O_ONE(&regs->ea, PTR_PC); /* use ea for PC */
  58         if (!ret)
  59                 ret = user_regset_copyout_zero(&pos, &count, &kbuf, &ubuf,
  60                                          PTR_STATUS * 4, -1);
  61
  62         return ret;
  63 }
  64
  65 /*
  66  * Set the thread state from a regset passed in via ptrace
  67  */
  68 static int genregs_set(struct task_struct *target,
  69                        const struct user_regset *regset,
  70                        unsigned int pos, unsigned int count,
  71                        const void *kbuf, const void __user *ubuf)
  72 {
  73         struct pt_regs *regs = task_pt_regs(target);
  74         const struct switch_stack *sw = (struct switch_stack *)regs - 1;
  75         int ret = 0;
  76
  77 #define REG_IGNORE_RANGE(START, END)            \
  78         if (!ret)                                       \
  79                 ret = user_regset_copyin_ignore(&pos, &count, &kbuf, &ubuf, \
  80                         START * 4, (END * 4) + 4);
  81
  82 #define REG_IN_ONE(PTR, LOC)    \
  83         if (!ret)                       \
  84                 ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, \
  85                         (void *)(PTR), LOC * 4, (LOC * 4) + 4);
  86
  87 #define REG_IN_RANGE(PTR, START, END)   \
  88         if (!ret)                               \
  89                 ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, \
  90                         (void *)(PTR), START * 4, (END * 4) + 4);
  91
  92         REG_IGNORE_RANGE(PTR_R0, PTR_R0);
  93         REG_IN_RANGE(&regs->r1, PTR_R1, PTR_R7);
  94         REG_IN_RANGE(&regs->r8, PTR_R8, PTR_R15);
  95         REG_IN_RANGE(sw, PTR_R16, PTR_R23);
  96         REG_IGNORE_RANGE(PTR_R24, PTR_R25); /* et and bt */
  97         REG_IN_ONE(&regs->gp, PTR_GP);
  98         REG_IN_ONE(&regs->sp, PTR_SP);
  99         REG_IN_ONE(&regs->fp, PTR_FP);
 100         REG_IN_ONE(&regs->ea, PTR_EA);
 101         REG_IGNORE_RANGE(PTR_BA, PTR_BA);
 102         REG_IN_ONE(&regs->ra, PTR_RA);
 103         REG_IN_ONE(&regs->ea, PTR_PC); /* use ea for PC */
 104         if (!ret)
 105                 ret = user_regset_copyin_ignore(&pos, &count, &kbuf, &ubuf,
 106                                          PTR_STATUS * 4, -1);
 107
 108         return ret;
 109 }
 110
 111 /*
 112  * Define the register sets available on Nios2 under Linux
 113  */
 114 enum nios2_regset {
 115         REGSET_GENERAL,
 116 };
 117
 118 static const struct user_regset nios2_regsets[] = {
 119         [REGSET_GENERAL] = {
 120                 .core_note_type = NT_PRSTATUS,
 121                 .n = NUM_PTRACE_REG,
 122                 .size = sizeof(unsigned long),
 123                 .align = sizeof(unsigned long),
 124                 .get = genregs_get,
 125                 .set = genregs_set,
 126         }
 127 };
 128
 129 static const struct user_regset_view nios2_user_view = {
 130         .name = "nios2",
 131         .e_machine = ELF_ARCH,
 132         .ei_osabi = ELF_OSABI,
 133         .regsets = nios2_regsets,
 134         .n = ARRAY_SIZE(nios2_regsets)
 135 };
 136
 137 const struct user_regset_view *task_user_regset_view(struct task_struct *task)
 138 {
 139         return &nios2_user_view;
 140 }
 141
 142 void ptrace_disable(struct task_struct *child)
 143 {
 144
 145 }
 146
 147 long arch_ptrace(struct task_struct *child, long request, unsigned long addr,
 148                  unsigned long data)
 149 {
 150         return ptrace_request(child, request, addr, data);
 151 }
 152
 153 asmlinkage int do_syscall_trace_enter(void)
 154 {
 155         int ret = 0;
 156
 157         if (test_thread_flag(TIF_SYSCALL_TRACE))
 158                 ret = tracehook_report_syscall_entry(task_pt_regs(current));
 159
 160         return ret;
 161 }
 162
 163 asmlinkage void do_syscall_trace_exit(void)
 164 {
 165         if (test_thread_flag(TIF_SYSCALL_TRACE))
 166                 tracehook_report_syscall_exit(task_pt_regs(current), 0);
 167 }