path: root/arch/mips/kernel/ptrace.c

/*
 * 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.
 *
 * Copyright (C) 1992 Ross Biro
 * Copyright (C) Linus Torvalds
 * Copyright (C) 1994, 95, 96, 97, 98, 2000 Ralf Baechle
 * Copyright (C) 1996 David S. Miller
 * Kevin D. Kissell, kevink@mips.com and Carsten Langgaard, carstenl@mips.com
 * Copyright (C) 1999 MIPS Technologies, Inc.
 * Copyright (C) 2000 Ulf Carlsson
 *
 * At this time Linux/MIPS64 only supports syscall tracing, even for 32-bit
 * binaries.
 */
#include <linux/compiler.h>
#include <linux/context_tracking.h>
#include <linux/elf.h>
#include <linux/kernel.h>
#include <linux/sched.h>
#include <linux/mm.h>
#include <linux/errno.h>
#include <linux/ptrace.h>
#include <linux/regset.h>
#include <linux/smp.h>
#include <linux/security.h>
#include <linux/stddef.h>
#include <linux/tracehook.h>
#include <linux/audit.h>
#include <linux/seccomp.h>
#include <linux/ftrace.h>

#include <asm/byteorder.h>
#include <asm/cpu.h>
#include <asm/cpu-info.h>
#include <asm/dsp.h>
#include <asm/fpu.h>
#include <asm/mipsregs.h>
#include <asm/mipsmtregs.h>
#include <asm/pgtable.h>
#include <asm/page.h>
#include <asm/syscall.h>
#include <asm/uaccess.h>
#include <asm/bootinfo.h>
#include <asm/reg.h>

#define CREATE_TRACE_POINTS
#include <trace/events/syscalls.h>

static void init_fp_ctx(struct task_struct *target)
{
	/* If FP has been used then the target already has context */
	if (tsk_used_math(target))
		return;

	/* Begin with data registers set to all 1s... */
	memset(&target->thread.fpu.fpr, ~0, sizeof(target->thread.fpu.fpr));

	/* FCSR has been preset by `mips_set_personality_nan'.  */

	/*
	 * Record that the target has "used" math, such that the context
	 * just initialised, and any modifications made by the caller,
	 * aren't discarded.
	 */
	set_stopped_child_used_math(target);
}

/*
 * Called by kernel/ptrace.c when detaching..
 *
 * Make sure single step bits etc are not set.
 */
void ptrace_disable(struct task_struct *child)
{
	/* Don't load the watchpoint registers for the ex-child. */
	clear_tsk_thread_flag(child, TIF_LOAD_WATCH);
}

/*
 * Poke at FCSR according to its mask.  Set the Cause bits even
 * if a corresponding Enable bit is set.  This will be noticed at
 * the time the thread is switched to and SIGFPE thrown accordingly.
 */
static void ptrace_setfcr31(struct task_struct *child, u32 value)
{
	u32 fcr31;
	u32 mask;

	fcr31 = child->thread.fpu.fcr31;
	mask = boot_cpu_data.fpu_msk31;
	child->thread.fpu.fcr31 = (value & ~mask) | (fcr31 & mask);
}

/*
 * Read a general register set.	 We always use the 64-bit format, even
 * for 32-bit kernels and for 32-bit processes on a 64-bit kernel.
 * Registers are sign extended to fill the available space.
 */
int ptrace_getregs(struct task_struct *child, struct user_pt_regs __user *data)
{
	struct pt_regs *regs;
	int i;

	if (!access_ok(VERIFY_WRITE, data, 38 * 8))
		return -EIO;

	regs = task_pt_regs(child);

	for (i = 0; i < 32; i++)
		__put_user((long)regs->regs[i], (__s64 __user *)&data->regs[i]);
	__put_user((long)regs->lo, (__s64 __user *)&data->lo);
	__put_user((long)regs->hi, (__s64 __user *)&data->hi);
	__put_user((long)regs->cp0_epc, (__s64 __user *)&data->cp0_epc);
	__put_user((long)regs->cp0_badvaddr, (__s64 __user *)&data->cp0_badvaddr);
	__put_user((long)regs->cp0_status, (__s64 __user *)&data->cp0_status);
	__put_user((long)regs->cp0_cause, (__s64 __user *)&data->cp0_cause);

	return 0;
}

/*
 * Write a general register set.  As for PTRACE_GETREGS, we always use
 * the 64-bit format.  On a 32-bit kernel only the lower order half
 * (according to endianness) will be used.
 */
int ptrace_setregs(struct task_struct *child, struct user_pt_regs __user *data)
{
	struct pt_regs *regs;
	int i;

	if (!access_ok(VERIFY_READ, data, 38 * 8))
		return -EIO;

	regs = task_pt_regs(child);

	for (i = 0; i < 32; i++)
		__get_user(regs->regs[i], (__s64 __user *)&data->regs[i]);
	__get_user(regs->lo, (__s64 __user *)&data->lo);
	__get_user(regs->hi, (__s64 __user *)&data->hi);
	__get_user(regs->cp0_epc, (__s64 __user *)&data->cp0_epc);

	/* badvaddr, status, and cause may not be written.  */

	return 0;
}

int ptrace_getfpregs(struct task_struct *child, __u32 __user *data)
{
	int i;

	if (!access_ok(VERIFY_WRITE, data, 33 * 8))
		return -EIO;

	if (tsk_used_math(child)) {
		union fpureg *fregs = get_fpu_regs(child);
		for (i = 0; i < 32; i++)
			__put_user(get_fpr64(&fregs[i], 0),
				   i + (__u64 __user *)data);
	} else {
		for (i = 0; i < 32; i++)
			__put_user((__u64) -