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                        struct membuf to)
  25 {
  26         const struct pt_regs *regs = task_pt_regs(target);
  27         const struct switch_stack *sw = (struct switch_stack *)regs - 1;
  28
  29         membuf_zero(&to, 4); // R0
  30         membuf_write(&to, &regs->r1, 7 * 4); // R1..R7
  31         membuf_write(&to, &regs->r8, 8 * 4); // R8..R15
  32         membuf_write(&to, sw, 8 * 4); // R16..R23
  33         membuf_zero(&to, 2 * 4); /* et and bt */
  34         membuf_store(&to, regs->gp);
  35         membuf_store(&to, regs->sp);
  36         membuf_store(&to, regs->fp);
  37         membuf_store(&to, regs->ea);
  38         membuf_zero(&to, 4); // PTR_BA
  39         membuf_store(&to, regs->ra);
  40         membuf_store(&to, regs->ea); /* use ea for PC */
  41         return membuf_zero(&to, (NUM_PTRACE_REG - PTR_PC) * 4);
  42 }
  43
  44 /*
  45  * Set the thread state from a regset passed in via ptrace
  46  */
  47 static int genregs_set(struct task_struct *target,
  48                        const struct user_regset *regset,
  49                        unsigned int pos, unsigned int count,
  50                        const void *kbuf, const void __user *ubuf)
  51 {
  52         struct pt_regs *regs = task_pt_regs(target);
  53         const struct switch_stack *sw = (struct switch_stack *)regs - 1;
  54         int ret = 0;
  55
  56 #define REG_IGNORE_RANGE(START, END)            \
  57         if (!ret)                                       \
  58                 ret = user_regset_copyin_ignore(&pos, &count, &kbuf, &ubuf, \
  59                         START * 4, (END * 4) + 4);
  60
  61 #define REG_IN_ONE(PTR, LOC)    \
  62         if (!ret)                       \
  63                 ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, \
  64                         (void *)(PTR), LOC * 4, (LOC * 4) + 4);
  65
  66 #define REG_IN_RANGE(PTR, START, END)   \
  67         if (!ret)                               \
  68                 ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, \
  69                         (void *)(PTR), START * 4, (END * 4) + 4);
  70
  71         REG_IGNORE_RANGE(PTR_R0, PTR_R0);
  72         REG_IN_RANGE(&regs->r1, PTR_R1, PTR_R7);
  73         REG_IN_RANGE(&regs->r8, PTR_R8, PTR_R15);
  74         REG_IN_RANGE(sw, PTR_R16, PTR_R23);
  75         REG_IGNORE_RANGE(PTR_R24, PTR_R25); /* et and bt */
  76         REG_IN_ONE(&regs->gp, PTR_GP);
  77         REG_IN_ONE(&regs->sp, PTR_SP);
  78         REG_IN_ONE(&regs->fp, PTR_FP);
  79         REG_IN_ONE(&regs->ea, PTR_EA);
  80         REG_IGNORE_RANGE(PTR_BA, PTR_BA);
  81         REG_IN_ONE(&regs->ra, PTR_RA);
  82         REG_IN_ONE(&regs->ea, PTR_PC); /* use ea for PC */
  83         if (!ret)
  84                 ret = user_regset_copyin_ignore(&pos, &count, &kbuf, &ubuf,
  85                                          PTR_STATUS * 4, -1);
  86
  87         return ret;
  88 }
  89
  90 /*
  91  * Define the register sets available on Nios2 under Linux
  92  */
  93 enum nios2_regset {
  94         REGSET_GENERAL,
  95 };
  96
  97 static const struct user_regset nios2_regsets[] = {
  98         [REGSET_GENERAL] = {
  99                 .core_note_type = NT_PRSTATUS,
 100                 .n = NUM_PTRACE_REG,
 101                 .size = sizeof(unsigned long),
 102                 .align = sizeof(unsigned long),
 103                 .regset_get = genregs_get,
 104                 .set = genregs_set,
 105         }
 106 };
 107
 108 static const struct user_regset_view nios2_user_view = {
 109         .name = "nios2",
 110         .e_machine = ELF_ARCH,
 111         .ei_osabi = ELF_OSABI,
 112         .regsets = nios2_regsets,
 113         .n = ARRAY_SIZE(nios2_regsets)
 114 };
 115
 116 const struct user_regset_view *task_user_regset_view(struct task_struct *task)
 117 {
 118         return &nios2_user_view;
 119 }
 120
 121 void ptrace_disable(struct task_struct *child)
 122 {
 123
 124 }
 125
 126 long arch_ptrace(struct task_struct *child, long request, unsigned long addr,
 127                  unsigned long data)
 128 {
 129         return ptrace_request(child, request, addr, data);
 130 }
 131
 132 asmlinkage int do_syscall_trace_enter(void)
 133 {
 134         int ret = 0;
 135
 136         if (test_thread_flag(TIF_SYSCALL_TRACE))
 137                 ret = tracehook_report_syscall_entry(task_pt_regs(current));
 138
 139         return ret;
 140 }
 141
 142 asmlinkage void do_syscall_trace_exit(void)
 143 {
 144         if (test_thread_flag(TIF_SYSCALL_TRACE))
 145                 tracehook_report_syscall_exit(task_pt_regs(current), 0);
 146 }