arch/c6x/kernel/ptrace.c

   1 /*
   2  *  Port on Texas Instruments TMS320C6x architecture
   3  *
   4  *  Copyright (C) 2004, 2006, 2009, 2010, 2011 Texas Instruments Incorporated
   5  *  Author: Aurelien Jacquiot (aurelien.jacquiot@jaluna.com)
   6  *
   7  *  Updated for 2.6.34: Mark Salter <msalter@redhat.com>
   8  *
   9  *  This program is free software; you can redistribute it and/or modify
  10  *  it under the terms of the GNU General Public License version 2 as
  11  *  published by the Free Software Foundation.
  12  */
  13 #include <linux/ptrace.h>
  14 #include <linux/tracehook.h>
  15 #include <linux/regset.h>
  16 #include <linux/elf.h>
  17
  18 #include <asm/cacheflush.h>
  19
  20 #define PT_REG_SIZE       (sizeof(struct pt_regs))
  21
  22 /*
  23  * Called by kernel/ptrace.c when detaching.
  24  */
  25 void ptrace_disable(struct task_struct *child)
  26 {
  27         /* nothing to do */
  28 }
  29
  30 /*
  31  * Get a register number from live pt_regs for the specified task.
  32  */
  33 static inline long get_reg(struct task_struct *task, int regno)
  34 {
  35         long *addr = (long *)task_pt_regs(task);
  36
  37         if (regno == PT_TSR || regno == PT_CSR)
  38                 return 0;
  39
  40         return addr[regno];
  41 }
  42
  43 /*
  44  * Write contents of register REGNO in task TASK.
  45  */
  46 static inline int put_reg(struct task_struct *task,
  47                           int regno,
  48                           unsigned long data)
  49 {
  50         unsigned long *addr = (unsigned long *)task_pt_regs(task);
  51
  52         if (regno != PT_TSR && regno != PT_CSR)
  53                 addr[regno] = data;
  54
  55         return 0;
  56 }
  57
  58 /* regset get/set implementations */
  59
  60 static int gpr_get(struct task_struct *target,
  61                    const struct user_regset *regset,
  62                    unsigned int pos, unsigned int count,
  63                    void *kbuf, void __user *ubuf)
  64 {
  65         struct pt_regs *regs = task_pt_regs(target);
  66
  67         return user_regset_copyout(&pos, &count, &kbuf, &ubuf,
  68                                    regs,
  69                                    0, sizeof(*regs));
  70 }
  71
  72 static int gpr_set(struct task_struct *target,
  73                    const struct user_regset *regset,
  74                    unsigned int pos, unsigned int count,
  75                    const void *kbuf, const void __user *ubuf)
  76 {
  77         int ret;
  78         struct pt_regs *regs = task_pt_regs(target);
  79
  80         /* Don't copyin TSR or CSR */
  81         ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf,
  82                                  &regs,
  83                                  0, PT_TSR * sizeof(long));
  84         if (ret)
  85                 return ret;
  86
  87         ret = user_regset_copyin_ignore(&pos, &count, &kbuf, &ubuf,
  88                                         PT_TSR * sizeof(long),
  89                                         (PT_TSR + 1) * sizeof(long));
  90         if (ret)
  91                 return ret;
  92
  93         ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf,
  94                                  &regs,
  95                                  (PT_TSR + 1) * sizeof(long),
  96                                  PT_CSR * sizeof(long));
  97         if (ret)
  98                 return ret;
  99
 100         ret = user_regset_copyin_ignore(&pos, &count, &kbuf, &ubuf,
 101                                         PT_CSR * sizeof(long),
 102                                         (PT_CSR + 1) * sizeof(long));
 103         if (ret)
 104                 return ret;
 105
 106         ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf,
 107                                  &regs,
 108                                  (PT_CSR + 1) * sizeof(long), -1);
 109         return ret;
 110 }
 111
 112 enum c6x_regset {
 113         REGSET_GPR,
 114 };
 115
 116 static const struct user_regset c6x_regsets[] = {
 117         [REGSET_GPR] = {
 118                 .core_note_type = NT_PRSTATUS,
 119                 .n = ELF_NGREG,
 120                 .size = sizeof(u32),
 121                 .align = sizeof(u32),
 122                 .get = gpr_get,
 123                 .set = gpr_set
 124         },
 125 };
 126
 127 static const struct user_regset_view user_c6x_native_view = {
 128         .name           = "tic6x",
 129         .e_machine      = EM_TI_C6000,
 130         .regsets        = c6x_regsets,
 131         .n              = ARRAY_SIZE(c6x_regsets),
 132 };
 133
 134 const struct user_regset_view *task_user_regset_view(struct task_struct *task)
 135 {
 136         return &user_c6x_native_view;
 137 }
 138
 139 /*
 140  * Perform ptrace request
 141  */
 142 long arch_ptrace(struct task_struct *child, long request,
 143                  unsigned long addr, unsigned long data)
 144 {
 145         int ret = 0;
 146
 147         switch (request) {
 148                 /*
 149                  * write the word at location addr.
 150                  */
 151         case PTRACE_POKETEXT:
 152                 ret = generic_ptrace_pokedata(child, addr, data);
 153                 if (ret == 0 && request == PTRACE_POKETEXT)
 154                         flush_icache_range(addr, addr + 4);
 155                 break;
 156         default:
 157                 ret = ptrace_request(child, request, addr, data);
 158                 break;
 159         }
 160
 161         return ret;
 162 }
 163
 164 /*
 165  * handle tracing of system call entry
 166  * - return the revised system call number or ULONG_MAX to cause ENOSYS
 167  */
 168 asmlinkage unsigned long syscall_trace_entry(struct pt_regs *regs)
 169 {
 170         if (tracehook_report_syscall_entry(regs))
 171                 /* tracing decided this syscall should not happen, so
 172                  * We'll return a bogus call number to get an ENOSYS
 173                  * error, but leave the original number in
 174                  * regs->orig_a4
 175                  */
 176                 return ULONG_MAX;
 177
 178         return regs->b0;
 179 }
 180
 181 /*
 182  * handle tracing of system call exit
 183  */
 184 asmlinkage void syscall_trace_exit(struct pt_regs *regs)
 185 {
 186         tracehook_report_syscall_exit(regs, 0);
 187 }