text: /*
   * SuperH process tracing
   *
   * Copyright (C) 1999, 2000  Kaz Kojima & Niibe Yutaka
   * Copyright (C) 2002 - 2009  Paul Mundt
   *
   * Audit support by Yuichi Nakamura <ynakam@hitachisoft.jp>
   *
   * This file is subject to the terms and conditions of the GNU General Public
   * License.  See the file "COPYING" in the main directory of this archive
   * for more details.
   */
  #include <linux/kernel.h>
  #include <linux/sched.h>
  #include <linux/mm.h>
  #include <linux/smp.h>
  #include <linux/errno.h>
  #include <linux/ptrace.h>
  #include <linux/user.h>
  #include <linux/security.h>
  #include <linux/signal.h>
  #include <linux/io.h>
  #include <linux/audit.h>
  #include <linux/seccomp.h>
  #include <linux/tracehook.h>
  #include <linux/elf.h>
  #include <linux/regset.h>
  #include <linux/hw_breakpoint.h>
  #include <asm/uaccess.h>
  #include <asm/pgtable.h>
  #include <asm/processor.h>
  #include <asm/mmu_context.h>
  #include <asm/syscalls.h>
  #include <asm/fpu.h>
  
  #define CREATE_TRACE_POINTS
  #include <trace/events/syscalls.h>
  
  /*
   * This routine will get a word off of the process kernel stack.
   */
  static inline int get_stack_long(struct task_struct *task, int offset)
  {
  	unsigned char *stack;
  
  	stack = (unsigned char *)task_pt_regs(task);
  	stack += offset;
  	return (*((int *)stack));
  }
  
  /*
   * This routine will put a word on the process kernel stack.
   */
  static inline int put_stack_long(struct task_struct *task, int offset,
  				 unsigned long data)
  {
  	unsigned char *stack;
  
  	stack = (unsigned char *)task_pt_regs(task);
  	stack += offset;
  	*(unsigned long *) stack = data;
  	return 0;
  }
  
  void ptrace_triggered(struct perf_event *bp,
  		      struct perf_sample_data *data, struct pt_regs *regs)
  {
  	struct perf_event_attr attr;
  
  	/*
  	 * Disable the breakpoint request here since ptrace has defined a
  	 * one-shot behaviour for breakpoint exceptions.
  	 */
  	attr = bp->attr;
  	attr.disabled = true;
  	modify_user_hw_breakpoint(bp, &attr);
  }
  
  static int set_single_step(struct task_struct *tsk, unsigned long addr)
  {
  	struct thread_struct *thread = &tsk->thread;
  	struct perf_event *bp;
  	struct perf_event_attr attr;
  
  	bp = thread->ptrace_bps[0];
  	if (!bp) {
  		ptrace_breakpoint_init(&attr);
  
  		attr.bp_addr = addr;
  		attr.bp_len = HW_BREAKPOINT_LEN_2;
  		attr.bp_type = HW_BREAKPOINT_R;
  
  		bp = register_user_hw_breakpoint(&attr, ptrace_triggered,
  						 NULL, tsk);
  		if (IS_ERR(bp))
  			return PTR_ERR(bp);
  
  		thread->ptrace_bps[0] = bp;
  	} else {
  		int err;
  
  		attr = bp->attr;
  		attr.bp_addr = addr;
  		/* reenable breakpoint */
  		attr.disabled = false;
  		err = modify_user_hw_breakpoint(bp, &attr);
  		if (unlikely(err))
  			return err;
  	}
  
  	return 0;
  }
  
  void user_enable_single_step(struct task_struct *child)
  {
  	unsigned long pc = get_stack_long(child, offsetof(struct pt_regs, pc));
  
  	set_tsk_thread_flag(child, TIF_SINGLESTEP);
  
  	set_single_step(child, pc);
  }
  
  void user_disable_single_step(struct task_struct *child)
  {
  	clear_tsk_thread_flag(child, TIF_SINGLESTEP);
  }
  
  /*
   * Called by kernel/ptrace.c when detaching..
   *
   * Make sure single step bits etc are not set.
   */
  void ptrace_disable(struct task_struct *child)
  {
  	user_disable_single_step(child);
  }
  
  static int genregs_get(struct task_struct *target,
  		       const struct user_regset *regset,
  		       unsigned int pos, unsigned int count,
  		       void *kbuf, void __user *ubuf)
  {
  	const struct pt_regs *regs = task_pt_regs(target);
  	int ret;
  
  	ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf,
  				  regs->regs,
  				  0, 16 * sizeof(unsigned long));
  	if (!ret)
  		/* PC, PR, SR, GBR, MACH, MACL, TRA */
  		ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf,
  					  &regs->pc,
  					  offsetof(struct pt_regs, pc),
  					  sizeof(struct pt_regs));
  	if (!ret)
  		ret = user_regset_copyout_zero(&pos, &count, &kbuf, &ubuf,
  					       sizeof(struct pt_regs), -1);
  
  	return ret;
  }
  
  static int genregs_set(struct task_struct *target,
  		       const struct user_regset *regset,
  		       unsigned int pos, unsigned int count,
  		       const void *kbuf, const void __user *ubuf)
  {
  	struct pt_regs *regs = task_pt_regs(target);
  	int ret;
  
  	ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf,
  				 regs->regs,
  				 0, 16 * sizeof(unsigned long));
  	if (!ret && count > 0)
  		ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf,
  					 &regs->pc,
  					 offsetof(struct pt_regs, pc),
  					 sizeof(struct pt_regs));
  	if (!ret)
  		ret = user_regset_copyin_ignore(&pos, &count, &kbuf, &ubuf,
  						sizeof(struct pt_regs), -1);
  
  	return ret;
  }
  
  #ifdef CONFIG_SH_FPU
  int fpregs_get(struct task_struct *target,
  	       const struct user_regset *regset,
  	       unsigned int pos, unsigned int count,
  	       void *kbuf, void __user *ubuf)
  {
  	int ret;
  
  	ret = init_fpu(target);
  	if (ret)
  		return ret;
  
  	if ((boot_cpu_data.flags & CPU_HAS_FPU))
  		return user_regset_copyout(&pos, &count, &kbuf, &ubuf,
  					   &target->thread.xstate->hardfpu, 0, -1);
  
  	return user_regset_copyout(&pos, &count, &kbuf, &ubuf,
  				   &target->thread.xstate->softfpu, 0, -1);
  }
  
  static int fpregs_set(struct task_struct *target,
  		       const struct user_regset *regset,
  		       unsigned int pos, unsigned int count,
  		       const void *kbuf, const void __user *ubuf)
  {
  	int ret;
  
  	ret = init_fpu(target);
  	if (ret)
  		return ret;
  
  	set_stopped_child_used_math(target);
  
  	if ((boot_cpu_data.flags & CPU_HAS_FPU))
  		return user_regset_copyin(&pos, &count, &kbuf, &ubuf,
  					  &target->thread.xstate->hardfpu, 0, -1);
  
  	return user_regset_copyin(&pos, &count, &kbuf, &ubuf,
  				  &target->thread.xstate->softfpu, 0, -1);
  }
  
  static int fpregs_active(struct task_struct *target,
  			 const struct user_regset *regset)
  {
  	return tsk_used_math(target) ? regset->n : 0;
  }
  #endif
  
  #ifdef CONFIG_SH_DSP
  static int dspregs_get(struct task_struct *target,
  		       const struct user_regset *regset,
  		       unsigned int pos, unsigned int count,
  		       void *kbuf, void __user *ubuf)
  {
  	const struct pt_dspregs *regs =
  		(struct pt_dspregs *)&target->thread.dsp_status.dsp_regs;
  	int ret;
  
  	ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf, regs,
  				  0, sizeof(struct pt_dspregs));
  	if (!ret)
  		ret = user_regset_copyout_zero(&pos, &count, &kbuf, &ubuf,
  					       sizeof(struct pt_dspregs), -1);
  
  	return ret;
  }
  
  static int dspregs_set(struct task_struct *target,
  		       const struct user_regset *regset,
  		       unsigned int pos, unsigned int count,
  		       const void *kbuf, const void __user *ubuf)
  {
  	struct pt_dspregs *regs =
  		(struct pt_dspregs *)&target->thread.dsp_status.dsp_regs;
  	int ret;
  
  	ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, regs,
  				 0, sizeof(struct pt_dspregs));
  	if (!ret)
  		ret = user_regset_copyin_ignore(&pos, &count, &kbuf, &ubuf,
  						sizeof(struct pt_dspregs), -1);
  
  	return ret;
  }
  
  static int dspregs_active(struct task_struct *target,
  			  const struct user_regset *regset)
  {
  	struct pt_regs *regs = task_pt_regs(target);
  
  	return regs->sr & SR_DSP ? regset->n : 0;
  }
  #endif
  
  const struct pt_regs_offset regoffset_table[] = {
  	REGS_OFFSET_NAME(0),
  	REGS_OFFSET_NAME(1),
  	REGS_OFFSET_NAME(2),
  	REGS_OFFSET_NAME(3),
  	REGS_OFFSET_NAME(4),
  	REGS_OFFSET_NAME(5),
  	REGS_OFFSET_NAME(6),
  	REGS_OFFSET_NAME(7),
  	REGS_OFFSET_NAME(8),
  	REGS_OFFSET_NAME(9),
  	REGS_OFFSET_NAME(10),
  	REGS_OFFSET_NAME(11),
  	REGS_OFFSET_NAME(12),
  	REGS_OFFSET_NAME(13),
  	REGS_OFFSET_NAME(14),
  	REGS_OFFSET_NAME(15),
  	REG_OFFSET_NAME(pc),
  	REG_OFFSET_NAME(pr),
  	REG_OFFSET_NAME(sr),
  	REG_OFFSET_NAME(gbr),
  	REG_OFFSET_NAME(mach),
  	REG_OFFSET_NAME(macl),
  	REG_OFFSET_NAME(tra),
  	REG_OFFSET_END,
  };
  
  /*
   * These are our native regset flavours.
   */
  enum sh_regset {
  	REGSET_GENERAL,
  #ifdef CONFIG_SH_FPU
  	REGSET_FPU,
  #endif
  #ifdef CONFIG_SH_DSP
  	REGSET_DSP,
  #endif
  };
  
  static const struct user_regset sh_regsets[] = {
  	/*
  	 * Format is:
  	 *	R0 --> R15
  	 *	PC, PR, SR, GBR, MACH, MACL, TRA
  	 */
  	[REGSET_GENERAL] = {
  		.core_note_type	= NT_PRSTATUS,
  		.n		= ELF_NGREG,
  		.size		= sizeof(long),
  		.align		= sizeof(long),
  		.get		= genregs_get,
  		.set		= genregs_set,
  	},
  
  #ifdef CONFIG_SH_FPU
  	[REGSET_FPU] = {
  		.core_note_type	= NT_PRFPREG,
  		.n		= sizeof(struct user_fpu_struct) / sizeof(long),
  		.size		= sizeof(long),
  		.align		= sizeof(long),
  		.get		= fpregs_get,
  		.set		= fpregs_set,
  		.active		= fpregs_active,
  	},
  #endif
  
  #ifdef CONFIG_SH_DSP
  	[REGSET_DSP] = {
  		.n		= sizeof(struct pt_dspregs) / sizeof(long),
  		.size		= sizeof(long),
  		.align		= sizeof(long),
  		.get		= dspregs_get,
  		.set		= dspregs_set,
  		.active		= dspregs_active,
  	},
  #endif
  };
  
  static const struct user_regset_view user_sh_native_view = {
  	.name		= "sh",
  	.e_machine	= EM_SH,
  	.regsets	= sh_regsets,
  	.n		= ARRAY_SIZE(sh_regsets),
  };
  
  const struct user_regset_view *task_user_regset_view(struct task_struct *task)
  {
  	return &user_sh_native_view;
  }
  
  long arch_ptrace(struct task_struct *child, long request,
  		 unsigned long addr, unsigned long data)
  {
  	unsigned long __user *datap = (unsigned long __user *)data;
  	int ret;
  
  	switch (request) {
  	/* read the word at location addr in the USER area. */
  	case PTRACE_PEEKUSR: {
  		unsigned long tmp;
  
  		ret = -EIO;
  		if ((addr & 3) || addr < 0 ||
  		    addr > sizeof(struct user) - 3)
  			break;
  
  		if (addr < sizeof(struct pt_regs))
  			tmp = get_stack_long(child, addr);
  		else if (addr >= offsetof(struct user, fpu) &&
  			 addr < offsetof(struct user, u_fpvalid)) {
  			if (!tsk_used_math(child)) {
  				if (addr == offsetof(struct user, fpu.fpscr))
  					tmp = FPSCR_INIT;
  				else
  					tmp = 0;
  			} else {
  				unsigned long index;
  				ret = init_fpu(child);
  				if (ret)
  					break;
  				index = addr - offsetof(struct user, fpu);
  				tmp = ((unsigned long *)child->thread.xstate)
  					[index >> 2];
  			}
  		} else if (addr == offsetof(struct user, u_fpvalid))
  			tmp = !!tsk_used_math(child);
  		else if (addr == PT_TEXT_ADDR)
  			tmp = child->mm->start_code;
  		else if (addr == PT_DATA_ADDR)
  			tmp = child->mm->start_data;
  		else if (addr == PT_TEXT_END_ADDR)
  			tmp = child->mm->end_code;
  		else if (addr == PT_TEXT_LEN)
  			tmp = child->mm->end_code - child->mm->start_code;
  		else
  			tmp = 0;
  		ret = put_user(tmp, datap);
  		break;
  	}
  
  	case PTRACE_POKEUSR: /* write the word at location addr in the USER area */
  		ret = -EIO;
  		if ((addr & 3) || addr < 0 ||
  		    addr > sizeof(struct user) - 3)
  			break;
  
  		if (addr < sizeof(struct pt_regs))
  			ret = put_stack_long(child, addr, data);
  		else if (addr >= offsetof(struct user, fpu) &&
  			 addr < offsetof(struct user, u_fpvalid)) {
  			unsigned long index;
  			ret = init_fpu(child);
  			if (ret)
  				break;
  			index = addr - offsetof(struct user, fpu);
  			set_stopped_child_used_math(child);
  			((unsigned long *)child->thread.xstate)
  				[index >> 2] = data;
  			ret = 0;
  		} else if (addr == offsetof(struct user, u_fpvalid)) {
  			conditional_stopped_child_used_math(data, child);
  			ret = 0;
  		}
  		break;
  
  	case PTRACE_GETREGS:
  		return copy_regset_to_user(child, &user_sh_native_view,
  					   REGSET_GENERAL,
  					   0, sizeof(struct pt_regs),
  					   datap);
  	case PTRACE_SETREGS:
  		return copy_regset_from_user(child, &user_sh_native_view,
  					     REGSET_GENERAL,
  					     0, sizeof(struct pt_regs),
  					     datap);
  #ifdef CONFIG_SH_FPU
  	case PTRACE_GETFPREGS:
  		return copy_regset_to_user(child, &user_sh_native_view,
  					   REGSET_FPU,
  					   0, sizeof(struct user_fpu_struct),
  					   datap);
  	case PTRACE_SETFPREGS:
  		return copy_regset_from_user(child, &user_sh_native_view,
  					     REGSET_FPU,
  					     0, sizeof(struct user_fpu_struct),
  					     datap);
  #endif
  #ifdef CONFIG_SH_DSP
  	case PTRACE_GETDSPREGS:
  		return copy_regset_to_user(child, &user_sh_native_view,
  					   REGSET_DSP,
  					   0, sizeof(struct pt_dspregs),
  					   datap);
  	case PTRACE_SETDSPREGS:
  		return copy_regset_from_user(child, &user_sh_native_view,
  					     REGSET_DSP,
  					     0, sizeof(struct pt_dspregs),
  					     datap);
  #endif
  	default:
  		ret = ptrace_request(child, request, addr, data);
  		break;
  	}
  
  	return ret;
  }
  
  static inline int audit_arch(void)
  {
  	int arch = EM_SH;
  
  #ifdef CONFIG_CPU_LITTLE_ENDIAN
  	arch |= __AUDIT_ARCH_LE;
  #endif
  
  	return arch;
  }
  
  asmlinkage long do_syscall_trace_enter(struct pt_regs *regs)
  {
  	long ret = 0;
  
  	secure_computing_strict(regs->regs[0]);
  
  	if (test_thread_flag(TIF_SYSCALL_TRACE) &&
  	    tracehook_report_syscall_entry(regs))
  		/*
  		 * Tracing decided this syscall should not happen.
  		 * We'll return a bogus call number to get an ENOSYS
  		 * error, but leave the original number in regs->regs[0].
  		 */
  		ret = -1L;
  
  	if (unlikely(test_thread_flag(TIF_SYSCALL_TRACEPOINT)))
  		trace_sys_enter(regs, regs->regs[0]);
  
  	audit_syscall_entry(audit_arch(), regs->regs[3],
  			    regs->regs[4], regs->regs[5],
  			    regs->regs[6], regs->regs[7]);
  
  	return ret ?: regs->regs[0];
  }
  
  asmlinkage void do_syscall_trace_leave(struct pt_regs *regs)
  {
  	int step;
  
  	audit_syscall_exit(regs);
  
  	if (unlikely(test_thread_flag(TIF_SYSCALL_TRACEPOINT)))
  		trace_sys_exit(regs, regs->regs[0]);
  
  	step = test_thread_flag(TIF_SINGLESTEP);
  	if (step || test_thread_flag(TIF_SYSCALL_TRACE))
  		tracehook_report_syscall_exit(regs, step);
  }
  