arch/nds32/kernel/ptrace.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 // Copyright (C) 2005-2017 Andes Technology Corporation
   3
   4 #include <linux/ptrace.h>
   5 #include <linux/regset.h>
   6 #include <linux/tracehook.h>
   7 #include <linux/elf.h>
   8 #include <linux/sched/task_stack.h>
   9
  10 enum nds32_regset {
  11         REGSET_GPR,
  12 };
  13
  14 static int gpr_get(struct task_struct *target,
  15                    const struct user_regset *regset,
  16                    unsigned int pos, unsigned int count,
  17                    void *kbuf, void __user * ubuf)
  18 {
  19         struct user_pt_regs *uregs = &task_pt_regs(target)->user_regs;
  20         return user_regset_copyout(&pos, &count, &kbuf, &ubuf, uregs, 0, -1);
  21 }
  22
  23 static int gpr_set(struct task_struct *target, const struct user_regset *regset,
  24                    unsigned int pos, unsigned int count,
  25                    const void *kbuf, const void __user * ubuf)
  26 {
  27         int err;
  28         struct user_pt_regs newregs = task_pt_regs(target)->user_regs;
  29
  30         err = user_regset_copyin(&pos, &count, &kbuf, &ubuf, &newregs, 0, -1);
  31         if (err)
  32                 return err;
  33
  34         task_pt_regs(target)->user_regs = newregs;
  35         return 0;
  36 }
  37
  38 static const struct user_regset nds32_regsets[] = {
  39         [REGSET_GPR] = {
  40                         .core_note_type = NT_PRSTATUS,
  41                         .n = sizeof(struct user_pt_regs) / sizeof(u32),
  42                         .size = sizeof(elf_greg_t),
  43                         .align = sizeof(elf_greg_t),
  44                         .get = gpr_get,
  45                         .set = gpr_set}
  46 };
  47
  48 static const struct user_regset_view nds32_user_view = {
  49         .name = "nds32",
  50         .e_machine = EM_NDS32,
  51         .regsets = nds32_regsets,
  52         .n = ARRAY_SIZE(nds32_regsets)
  53 };
  54
  55 const struct user_regset_view *task_user_regset_view(struct task_struct *task)
  56 {
  57         return &nds32_user_view;
  58 }
  59
  60 void ptrace_disable(struct task_struct *child)
  61 {
  62         user_disable_single_step(child);
  63 }
  64
  65 /* do_ptrace()
  66  *
  67  * Provide ptrace defined service.
  68  */
  69 long arch_ptrace(struct task_struct *child, long request, unsigned long addr,
  70                  unsigned long data)
  71 {
  72         int ret = -EIO;
  73
  74         switch (request) {
  75         default:
  76                 ret = ptrace_request(child, request, addr, data);
  77                 break;
  78         }
  79
  80         return ret;
  81 }
  82
  83 void user_enable_single_step(struct task_struct *child)
  84 {
  85         struct pt_regs *regs;
  86         regs = task_pt_regs(child);
  87         regs->ipsw |= PSW_mskHSS;
  88         set_tsk_thread_flag(child, TIF_SINGLESTEP);
  89 }
  90
  91 void user_disable_single_step(struct task_struct *child)
  92 {
  93         struct pt_regs *regs;
  94         regs = task_pt_regs(child);
  95         regs->ipsw &= ~PSW_mskHSS;
  96         clear_tsk_thread_flag(child, TIF_SINGLESTEP);
  97 }
  98
  99 /* sys_trace()
 100  *
 101  * syscall trace handler.
 102  */
 103
 104 asmlinkage int syscall_trace_enter(struct pt_regs *regs)
 105 {
 106         if (test_thread_flag(TIF_SYSCALL_TRACE)) {
 107                 if (tracehook_report_syscall_entry(regs))
 108                         forget_syscall(regs);
 109         }
 110         return regs->syscallno;
 111 }
 112
 113 asmlinkage void syscall_trace_leave(struct pt_regs *regs)
 114 {
 115         int step = test_thread_flag(TIF_SINGLESTEP);
 116         if (step || test_thread_flag(TIF_SYSCALL_TRACE))
 117                 tracehook_report_syscall_exit(regs, step);
 118
 119 }