arch/riscv/kernel/ptrace.c

   1 /*
   2  * Copyright 2010 Tilera Corporation. All Rights Reserved.
   3  * Copyright 2015 Regents of the University of California
   4  * Copyright 2017 SiFive
   5  *
   6  *   This program is free software; you can redistribute it and/or
   7  *   modify it under the terms of the GNU General Public License
   8  *   as published by the Free Software Foundation, version 2.
   9  *
  10  *   This program is distributed in the hope that it will be useful,
  11  *   but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13  *   GNU General Public License for more details.
  14  *
  15  * Copied from arch/tile/kernel/ptrace.c
  16  */
  17
  18 #include <asm/ptrace.h>
  19 #include <asm/syscall.h>
  20 #include <asm/thread_info.h>
  21 #include <linux/ptrace.h>
  22 #include <linux/elf.h>
  23 #include <linux/regset.h>
  24 #include <linux/sched.h>
  25 #include <linux/sched/task_stack.h>
  26 #include <linux/tracehook.h>
  27 #include <trace/events/syscalls.h>
  28
  29 enum riscv_regset {
  30         REGSET_X,
  31 };
  32
  33 static int riscv_gpr_get(struct task_struct *target,
  34                          const struct user_regset *regset,
  35                          unsigned int pos, unsigned int count,
  36                          void *kbuf, void __user *ubuf)
  37 {
  38         struct pt_regs *regs;
  39
  40         regs = task_pt_regs(target);
  41         return user_regset_copyout(&pos, &count, &kbuf, &ubuf, regs, 0, -1);
  42 }
  43
  44 static int riscv_gpr_set(struct task_struct *target,
  45                          const struct user_regset *regset,
  46                          unsigned int pos, unsigned int count,
  47                          const void *kbuf, const void __user *ubuf)
  48 {
  49         int ret;
  50         struct pt_regs *regs;
  51
  52         regs = task_pt_regs(target);
  53         ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, &regs, 0, -1);
  54         return ret;
  55 }
  56
  57
  58 static const struct user_regset riscv_user_regset[] = {
  59         [REGSET_X] = {
  60                 .core_note_type = NT_PRSTATUS,
  61                 .n = ELF_NGREG,
  62                 .size = sizeof(elf_greg_t),
  63                 .align = sizeof(elf_greg_t),
  64                 .get = &riscv_gpr_get,
  65                 .set = &riscv_gpr_set,
  66         },
  67 };
  68
  69 static const struct user_regset_view riscv_user_native_view = {
  70         .name = "riscv",
  71         .e_machine = EM_RISCV,
  72         .regsets = riscv_user_regset,
  73         .n = ARRAY_SIZE(riscv_user_regset),
  74 };
  75
  76 const struct user_regset_view *task_user_regset_view(struct task_struct *task)
  77 {
  78         return &riscv_user_native_view;
  79 }
  80
  81 void ptrace_disable(struct task_struct *child)
  82 {
  83         clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE);
  84 }
  85
  86 long arch_ptrace(struct task_struct *child, long request,
  87                  unsigned long addr, unsigned long data)
  88 {
  89         long ret = -EIO;
  90
  91         switch (request) {
  92         default:
  93                 ret = ptrace_request(child, request, addr, data);
  94                 break;
  95         }
  96
  97         return ret;
  98 }
  99
 100 /*
 101  * Allows PTRACE_SYSCALL to work.  These are called from entry.S in
 102  * {handle,ret_from}_syscall.
 103  */
 104 void do_syscall_trace_enter(struct pt_regs *regs)
 105 {
 106         if (test_thread_flag(TIF_SYSCALL_TRACE))
 107                 if (tracehook_report_syscall_entry(regs))
 108                         syscall_set_nr(current, regs, -1);
 109
 110 #ifdef CONFIG_HAVE_SYSCALL_TRACEPOINTS
 111         if (test_thread_flag(TIF_SYSCALL_TRACEPOINT))
 112                 trace_sys_enter(regs, syscall_get_nr(current, regs));
 113 #endif
 114 }
 115
 116 void do_syscall_trace_exit(struct pt_regs *regs)
 117 {
 118         if (test_thread_flag(TIF_SYSCALL_TRACE))
 119                 tracehook_report_syscall_exit(regs, 0);
 120
 121 #ifdef CONFIG_HAVE_SYSCALL_TRACEPOINTS
 122         if (test_thread_flag(TIF_SYSCALL_TRACEPOINT))
 123                 trace_sys_exit(regs, regs->regs[0]);
 124 #endif
 125 }