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/uaccess.h>
  19 #include <linux/user.h>
  20
  21 static int genregs_get(struct task_struct *target,
  22                        const struct user_regset *regset,
  23                        struct membuf to)
  24 {
  25         const struct pt_regs *regs = task_pt_regs(target);
  26         const struct switch_stack *sw = (struct switch_stack *)regs - 1;
  27
  28         membuf_zero(&to, 4); // R0
  29         membuf_write(&to, &regs->r1, 7 * 4); // R1..R7
  30         membuf_write(&to, &regs->r8, 8 * 4); // R8..R15
  31         membuf_write(&to, sw, 8 * 4); // R16..R23
  32         membuf_zero(&to, 2 * 4); /* et and bt */
  33         membuf_store(&to, regs->gp);
  34         membuf_store(&to, regs->sp);
  35         membuf_store(&to, regs->fp);
  36         membuf_store(&to, regs->ea);
  37         membuf_zero(&to, 4); // PTR_BA
  38         membuf_store(&to, regs->ra);
  39         membuf_store(&to, regs->ea); /* use ea for PC */
  40         return membuf_zero(&to, (NUM_PTRACE_REG - PTR_PC) * 4);
  41 }
  42
  43 /*
  44  * Set the thread state from a regset passed in via ptrace
  45  */
  46 static int genregs_set(struct task_struct *target,
  47                        const struct user_regset *regset,
  48                        unsigned int pos, unsigned int count,
  49                        const void *kbuf, const void __user *ubuf)
  50 {
  51         struct pt_regs *regs = task_pt_regs(target);
  52         const struct switch_stack *sw = (struct switch_stack *)regs - 1;
  53         int ret = 0;
  54
  55 #define REG_IGNORE_RANGE(START, END)            \
  56         if (!ret)                                       \
  57                 user_regset_copyin_ignore(&pos, &count, &kbuf, &ubuf, \
  58                         START * 4, (END * 4) + 4);
  59
  60 #define REG_IN_ONE(PTR, LOC)    \
  61         if (!ret)                       \
  62                 ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, \
  63                         (void *)(PTR), LOC * 4, (LOC * 4) + 4);
  64
  65 #define REG_IN_RANGE(PTR, START, END)   \
  66         if (!ret)                               \
  67                 ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, \
  68                         (void *)(PTR), START * 4, (END * 4) + 4);
  69
  70         REG_IGNORE_RANGE(PTR_R0, PTR_R0);
  71         REG_IN_RANGE(&regs->r1, PTR_R1, PTR_R7);
  72         REG_IN_RANGE(&regs->r8, PTR_R8, PTR_R15);
  73         REG_IN_RANGE(sw, PTR_R16, PTR_R23);
  74         REG_IGNORE_RANGE(PTR_R24, PTR_R25); /* et and bt */
  75         REG_IN_ONE(&regs->gp, PTR_GP);
  76         REG_IN_ONE(&regs->sp, PTR_SP);
  77         REG_IN_ONE(&regs->fp, PTR_FP);
  78         REG_IN_ONE(&regs->ea, PTR_EA);
  79         REG_IGNORE_RANGE(PTR_BA, PTR_BA);
  80         REG_IN_ONE(&regs->ra, PTR_RA);
  81         REG_IN_ONE(&regs->ea, PTR_PC); /* use ea for PC */
  82         if (!ret)
  83                 user_regset_copyin_ignore(&pos, &count, &kbuf, &ubuf,
  84                                           PTR_STATUS * 4, -1);
  85
  86         return ret;
  87 }
  88
  89 /*
  90  * Define the register sets available on Nios2 under Linux
  91  */
  92 enum nios2_regset {
  93         REGSET_GENERAL,
  94 };
  95
  96 static const struct user_regset nios2_regsets[] = {
  97         [REGSET_GENERAL] = {
  98                 .core_note_type = NT_PRSTATUS,
  99                 .n = NUM_PTRACE_REG,
 100                 .size = sizeof(unsigned long),
 101                 .align = sizeof(unsigned long),
 102                 .regset_get = genregs_get,
 103                 .set = genregs_set,
 104         }
 105 };
 106
 107 static const struct user_regset_view nios2_user_view = {
 108         .name = "nios2",
 109         .e_machine = ELF_ARCH,
 110         .ei_osabi = ELF_OSABI,
 111         .regsets = nios2_regsets,
 112         .n = ARRAY_SIZE(nios2_regsets)
 113 };
 114
 115 const struct user_regset_view *task_user_regset_view(struct task_struct *task)
 116 {
 117         return &nios2_user_view;
 118 }
 119
 120 void ptrace_disable(struct task_struct *child)
 121 {
 122
 123 }
 124
 125 long arch_ptrace(struct task_struct *child, long request, unsigned long addr,
 126                  unsigned long data)
 127 {
 128         return ptrace_request(child, request, addr, data);
 129 }
 130
 131 asmlinkage int do_syscall_trace_enter(void)
 132 {
 133         int ret = 0;
 134
 135         if (test_thread_flag(TIF_SYSCALL_TRACE))
 136                 ret = ptrace_report_syscall_entry(task_pt_regs(current));
 137
 138         return ret;
 139 }
 140
 141 asmlinkage void do_syscall_trace_exit(void)
 142 {
 143         if (test_thread_flag(TIF_SYSCALL_TRACE))
 144                 ptrace_report_syscall_exit(task_pt_regs(current), 0);
 145 }