LXR linux/arch/c6x/kernel/ptrace.c

   1// SPDX-License-Identifier: GPL-2.0-only
   2/*
   3 *  Port on Texas Instruments TMS320C6x architecture
   4 *
   5 *  Copyright (C) 2004, 2006, 2009, 2010, 2011 Texas Instruments Incorporated
   6 *  Author: Aurelien Jacquiot (aurelien.jacquiot@jaluna.com)
   7 *
   8 *  Updated for 2.6.34: Mark Salter <msalter@redhat.com>
   9 */
  10#include <linux/ptrace.h>
  11#include <linux/tracehook.h>
  12#include <linux/regset.h>
  13#include <linux/elf.h>
  14#include <linux/sched/task_stack.h>
  15
  16#include <asm/cacheflush.h>
  17
  18#define PT_REG_SIZE       (sizeof(struct pt_regs))
  19
  20/*
  21 * Called by kernel/ptrace.c when detaching.
  22 */
  23void ptrace_disable(struct task_struct *child)
  24{
  25        /* nothing to do */
  26}
  27
  28/*
  29 * Get a register number from live pt_regs for the specified task.
  30 */
  31static inline long get_reg(struct task_struct *task, int regno)
  32{
  33        long *addr = (long *)task_pt_regs(task);
  34
  35        if (regno == PT_TSR || regno == PT_CSR)
  36                return 0;
  37
  38        return addr[regno];
  39}
  40
  41/*
  42 * Write contents of register REGNO in task TASK.
  43 */
  44static inline int put_reg(struct task_struct *task,
  45                          int regno,
  46                          unsigned long data)
  47{
  48        unsigned long *addr = (unsigned long *)task_pt_regs(task);
  49
  50        if (regno != PT_TSR && regno != PT_CSR)
  51                addr[regno] = data;
  52
  53        return 0;
  54}
  55
  56/* regset get/set implementations */
  57
  58static int gpr_get(struct task_struct *target,
  59                   const struct user_regset *regset,
  60                   struct membuf to)
  61{
  62        return membuf_write(&to, task_pt_regs(target), sizeof(struct pt_regs));
  63}
  64
  65enum c6x_regset {
  66        REGSET_GPR,
  67};
  68
  69static const struct user_regset c6x_regsets[] = {
  70        [REGSET_GPR] = {
  71                .core_note_type = NT_PRSTATUS,
  72                .n = ELF_NGREG,
  73                .size = sizeof(u32),
  74                .align = sizeof(u32),
  75                .regset_get = gpr_get,
  76        },
  77};
  78
  79static const struct user_regset_view user_c6x_native_view = {
  80        .name           = "tic6x",
  81        .e_machine      = EM_TI_C6000,
  82        .regsets        = c6x_regsets,
  83        .n              = ARRAY_SIZE(c6x_regsets),
  84};
  85
  86const struct user_regset_view *task_user_regset_view(struct task_struct *task)
  87{
  88        return &user_c6x_native_view;
  89}
  90
  91/*
  92 * Perform ptrace request
  93 */
  94long arch_ptrace(struct task_struct *child, long request,
  95                 unsigned long addr, unsigned long data)
  96{
  97        int ret = 0;
  98
  99        switch (request) {
 100                /*
 101                 * write the word at location addr.
 102                 */
 103        case PTRACE_POKETEXT:
 104                ret = generic_ptrace_pokedata(child, addr, data);
 105                if (ret == 0 && request == PTRACE_POKETEXT)
 106                        flush_icache_range(addr, addr + 4);
 107                break;
 108        default:
 109                ret = ptrace_request(child, request, addr, data);
 110                break;
 111        }
 112
 113        return ret;
 114}
 115
 116/*
 117 * handle tracing of system call entry
 118 * - return the revised system call number or ULONG_MAX to cause ENOSYS
 119 */
 120asmlinkage unsigned long syscall_trace_entry(struct pt_regs *regs)
 121{
 122        if (tracehook_report_syscall_entry(regs))
 123                /* tracing decided this syscall should not happen, so
 124                 * We'll return a bogus call number to get an ENOSYS
 125                 * error, but leave the original number in
 126                 * regs->orig_a4
 127                 */
 128                return ULONG_MAX;
 129
 130        return regs->b0;
 131}
 132
 133/*
 134 * handle tracing of system call exit
 135 */
 136asmlinkage void syscall_trace_exit(struct pt_regs *regs)
 137{
 138        tracehook_report_syscall_exit(regs, 0);
 139}
 140