arch/x86/kernel/ptrace_64.c - SHIFTPHONES/mainline/linux - Gitiles

 /* By Ross Biro 1/23/92 */
 /*
  * Pentium III FXSR, SSE support
  *	Gareth Hughes <gareth@valinux.com>, May 2000
  *
  * x86-64 port 2000-2002 Andi Kleen
  */

 #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/audit.h>
 #include <linux/seccomp.h>
 #include <linux/signal.h>

 #include <asm/uaccess.h>
 #include <asm/pgtable.h>
 #include <asm/system.h>
 #include <asm/processor.h>
 #include <asm/prctl.h>
 #include <asm/i387.h>
 #include <asm/debugreg.h>
 #include <asm/ldt.h>
 #include <asm/desc.h>
 #include <asm/proto.h>
 #include <asm/ia32.h>

 /*
  * does not yet catch signals sent when the child dies.
  * in exit.c or in signal.c.
  */

 /*
  * Determines which flags the user has access to [1 = access, 0 = no access].
  * Prohibits changing ID(21), VIP(20), VIF(19), VM(17), IOPL(12-13), IF(9).
  * Also masks reserved bits (63-22, 15, 5, 3, 1).
  */
 #define FLAG_MASK 0x54dd5UL

 /*
  * Called by kernel/ptrace.c when detaching..
  *
  * Make sure the single step bit is not set.
  */
 void ptrace_disable(struct task_struct *child)
 {
 	user_disable_single_step(child);
 }

 static unsigned long *pt_regs_access(struct pt_regs *regs, unsigned long offset)
 {
 	BUILD_BUG_ON(offsetof(struct pt_regs, r15) != 0);
 	return &regs->r15 + (offset / sizeof(regs->r15));
 }

 static int putreg(struct task_struct *child,
 	unsigned long regno, unsigned long value)
 {
 	struct pt_regs *regs = task_pt_regs(child);
 	switch (regno) {
 		case offsetof(struct user_regs_struct,fs):
 			if (value && (value & 3) != 3)
 				return -EIO;
 			child->thread.fsindex = value & 0xffff;
 			return 0;
 		case offsetof(struct user_regs_struct,gs):
 			if (value && (value & 3) != 3)
 				return -EIO;
 			child->thread.gsindex = value & 0xffff;
 			return 0;
 		case offsetof(struct user_regs_struct,ds):
 			if (value && (value & 3) != 3)
 				return -EIO;
 			child->thread.ds = value & 0xffff;
 			return 0;
 		case offsetof(struct user_regs_struct,es):
 			if (value && (value & 3) != 3)
 				return -EIO;
 			child->thread.es = value & 0xffff;
 			return 0;
 		case offsetof(struct user_regs_struct,ss):
 			if ((value & 3) != 3)
 				return -EIO;
 			value &= 0xffff;
 			return 0;
 		case offsetof(struct user_regs_struct,fs_base):
 			if (value >= TASK_SIZE_OF(child))
 				return -EIO;
 			/*
 			 * When changing the segment base, use do_arch_prctl
 			 * to set either thread.fs or thread.fsindex and the
 			 * corresponding GDT slot.
 			 */
 			if (child->thread.fs != value)
 				return do_arch_prctl(child, ARCH_SET_FS, value);
 			return 0;
 		case offsetof(struct user_regs_struct,gs_base):
 			/*
 			 * Exactly the same here as the %fs handling above.
 			 */
 			if (value >= TASK_SIZE_OF(child))
 				return -EIO;
 			if (child->thread.gs != value)
 				return do_arch_prctl(child, ARCH_SET_GS, value);
 			return 0;
 		case offsetof(struct user_regs_struct, eflags):
 			value &= FLAG_MASK;
 			/*
 			 * If the user value contains TF, mark that
 			 * it was not "us" (the debugger) that set it.
 			 * If not, make sure it stays set if we had.
 			 */
 			if (value & X86_EFLAGS_TF)
 				clear_tsk_thread_flag(child, TIF_FORCED_TF);
 			else if (test_tsk_thread_flag(child, TIF_FORCED_TF))
 				value |= X86_EFLAGS_TF;
 			value |= regs->eflags & ~FLAG_MASK;
 			break;
 		case offsetof(struct user_regs_struct,cs):
 			if ((value & 3) != 3)
 				return -EIO;
 			value &= 0xffff;
 			break;
 	}
 	*pt_regs_access(regs, regno) = value;
 	return 0;
 }

 static unsigned long getreg(struct task_struct *child, unsigned long regno)
 {
 	struct pt_regs *regs = task_pt_regs(child);
 	unsigned long val;
 	switch (regno) {
 		case offsetof(struct user_regs_struct, fs):
 			return child->thread.fsindex;
 		case offsetof(struct user_regs_struct, gs):
 			return child->thread.gsindex;
 		case offsetof(struct user_regs_struct, ds):
 			return child->thread.ds;
 		case offsetof(struct user_regs_struct, es):
 			return child->thread.es;
 		case offsetof(struct user_regs_struct, fs_base):
 			/*
 			 * do_arch_prctl may have used a GDT slot instead of
 			 * the MSR.  To userland, it appears the same either
 			 * way, except the %fs segment selector might not be 0.
 			 */
 			if (child->thread.fs != 0)
 				return child->thread.fs;
 			if (child->thread.fsindex != FS_TLS_SEL)
 				return 0;
 			return get_desc_base(&child->thread.tls_array[FS_TLS]);
 		case offsetof(struct user_regs_struct, gs_base):
 			/*
 			 * Exactly the same here as the %fs handling above.
 			 */
 			if (child->thread.gs != 0)
 				return child->thread.gs;
 			if (child->thread.gsindex != GS_TLS_SEL)
 				return 0;
 			return get_desc_base(&child->thread.tls_array[GS_TLS]);
 		case offsetof(struct user_regs_struct, eflags):
 			/*
 			 * If the debugger set TF, hide it from the readout.
 			 */
 			val = regs->eflags;
 			if (test_tsk_thread_flag(child, TIF_IA32))
 				val &= 0xffffffff;
 			if (test_tsk_thread_flag(child, TIF_FORCED_TF))
 				val &= ~X86_EFLAGS_TF;
 			return val;
 		default:
 			val = *pt_regs_access(regs, regno);
 			if (test_tsk_thread_flag(child, TIF_IA32))
 				val &= 0xffffffff;
 			return val;
 	}

 }

 unsigned long ptrace_get_debugreg(struct task_struct *child, int n)
 {
 	switch (n) {
 	case 0:		return child->thread.debugreg0;
 	case 1:		return child->thread.debugreg1;
 	case 2:		return child->thread.debugreg2;
 	case 3:		return child->thread.debugreg3;
 	case 6:		return child->thread.debugreg6;
 	case 7:		return child->thread.debugreg7;
 	}
 	return 0;
 }

 int ptrace_set_debugreg(struct task_struct *child, int n, unsigned long data)
 {
 	int i;

 	if (n < 4) {
 		int dsize = test_tsk_thread_flag(child, TIF_IA32) ? 3 : 7;
 		if (unlikely(data >= TASK_SIZE_OF(child) - dsize))
 			return -EIO;
 	}

 	switch (n) {
 	case 0:		child->thread.debugreg0 = data; break;
 	case 1:		child->thread.debugreg1 = data; break;
 	case 2:		child->thread.debugreg2 = data; break;
 	case 3:		child->thread.debugreg3 = data; break;

 	case 6:
 		if (data >> 32)
 			return -EIO;
 		child->thread.debugreg6 = data;
 		break;

 	case 7:
 		/*
 		 * See ptrace_32.c for an explanation of this awkward check.
 		 */
 		data &= ~DR_CONTROL_RESERVED;
 		for (i = 0; i < 4; i++)
 			if ((0x5554 >> ((data >> (16 + 4*i)) & 0xf)) & 1)
 				return -EIO;
 		child->thread.debugreg7 = data;
 		if (data)
 			set_tsk_thread_flag(child, TIF_DEBUG);
 		else
 			clear_tsk_thread_flag(child, TIF_DEBUG);
 		break;
 	}

 	return 0;
 }

 long arch_ptrace(struct task_struct *child, long request, long addr, long data)
 {
 	long ret;
 	unsigned ui;

 	switch (request) {
 	/* when I and D space are separate, these will need to be fixed. */
 	case PTRACE_PEEKTEXT: /* read word at location addr. */
 	case PTRACE_PEEKDATA:
 		ret = generic_ptrace_peekdata(child, addr, data);
 		break;

 	/* read the word at location addr in the USER area. */
 	case PTRACE_PEEKUSR: {
 		unsigned long tmp;

 		ret = -EIO;
 		if ((addr & 7) ||
 		    addr > sizeof(struct user) - 7)
 			break;

 		tmp = 0;
 		if (addr < sizeof(struct user_regs_struct))
 			tmp = getreg(child, addr);
 		else if (addr >= offsetof(struct user, u_debugreg[0])) {
 			addr -= offsetof(struct user, u_debugreg[0]);
 			tmp = ptrace_get_debugreg(child, addr / sizeof(long));
 		}

 		ret = put_user(tmp,(unsigned long __user *) data);
 		break;
 	}

 	/* when I and D space are separate, this will have to be fixed. */
 	case PTRACE_POKETEXT: /* write the word at location addr. */
 	case PTRACE_POKEDATA:
 		ret = generic_ptrace_pokedata(child, addr, data);
 		break;

 	case PTRACE_POKEUSR: /* write the word at location addr in the USER area */
 		ret = -EIO;
 		if ((addr & 7) ||
 		    addr > sizeof(struct user) - 7)
 			break;

 		if (addr < sizeof(struct user_regs_struct))
 			ret = putreg(child, addr, data);
 		else if (addr >= offsetof(struct user, u_debugreg[0])) {
 			addr -= offsetof(struct user, u_debugreg[0]);
 			ret = ptrace_set_debugreg(child,
 						  addr / sizeof(long), data);
 		}
 		break;

 #ifdef CONFIG_IA32_EMULATION
 		/* This makes only sense with 32bit programs. Allow a
 		   64bit debugger to fully examine them too. Better
 		   don't use it against 64bit processes, use
 		   PTRACE_ARCH_PRCTL instead. */
 	case PTRACE_GET_THREAD_AREA:
 		if (addr < 0)
 			return -EIO;
 		ret = do_get_thread_area(child, addr,
 					 (struct user_desc __user *) data);

 		break;
 	case PTRACE_SET_THREAD_AREA:
 		if (addr < 0)
 			return -EIO;
 		ret = do_set_thread_area(child, addr,
 					 (struct user_desc __user *) data, 0);
 		break;
 #endif
 		/* normal 64bit interface to access TLS data.
 		   Works just like arch_prctl, except that the arguments
 		   are reversed. */
 	case PTRACE_ARCH_PRCTL:
 		ret = do_arch_prctl(child, data, addr);
 		break;

 	case PTRACE_GETREGS: { /* Get all gp regs from the child. */
 	  	if (!access_ok(VERIFY_WRITE, (unsigned __user *)data,
 			       sizeof(struct user_regs_struct))) {
 			ret = -EIO;
 			break;
 		}
 		ret = 0;
 		for (ui = 0; ui < sizeof(struct user_regs_struct); ui += sizeof(long)) {
 			ret |= __put_user(getreg(child, ui),(unsigned long __user *) data);
 			data += sizeof(long);
 		}
 		break;
 	}

 	case PTRACE_SETREGS: { /* Set all gp regs in the child. */
 		unsigned long tmp;
 	  	if (!access_ok(VERIFY_READ, (unsigned __user *)data,
 			       sizeof(struct user_regs_struct))) {
 			ret = -EIO;
 			break;
 		}
 		ret = 0;
 		for (ui = 0; ui < sizeof(struct user_regs_struct); ui += sizeof(long)) {
 			ret = __get_user(tmp, (unsigned long __user *) data);
 			if (ret)
 				break;
 			ret = putreg(child, ui, tmp);
 			if (ret)
 				break;
 			data += sizeof(long);
 		}
 		break;
 	}

 	case PTRACE_GETFPREGS: { /* Get the child extended FPU state. */
 		if (!access_ok(VERIFY_WRITE, (unsigned __user *)data,
 			       sizeof(struct user_i387_struct))) {
 			ret = -EIO;
 			break;
 		}
 		ret = get_fpregs((struct user_i387_struct __user *)data, child);
 		break;
 	}

 	case PTRACE_SETFPREGS: { /* Set the child extended FPU state. */
 		if (!access_ok(VERIFY_READ, (unsigned __user *)data,
 			       sizeof(struct user_i387_struct))) {
 			ret = -EIO;
 			break;
 		}
 		set_stopped_child_used_math(child);
 		ret = set_fpregs(child, (struct user_i387_struct __user *)data);
 		break;
 	}

 	default:
 		ret = ptrace_request(child, request, addr, data);
 		break;
 	}
 	return ret;
 }

 static void syscall_trace(struct pt_regs *regs)
 {

 #if 0
 	printk("trace %s rip %lx rsp %lx rax %d origrax %d caller %lx tiflags %x ptrace %x\n",
 	       current->comm,
 	       regs->rip, regs->rsp, regs->rax, regs->orig_rax, __builtin_return_address(0),
 	       current_thread_info()->flags, current->ptrace);
 #endif

 	ptrace_notify(SIGTRAP | ((current->ptrace & PT_TRACESYSGOOD)
 				? 0x80 : 0));
 	/*
 	 * this isn't the same as continuing with a signal, but it will do
 	 * for normal use.  strace only continues with a signal if the
 	 * stopping signal is not SIGTRAP.  -brl
 	 */
 	if (current->exit_code) {
 		send_sig(current->exit_code, current, 1);
 		current->exit_code = 0;
 	}
 }

 asmlinkage void syscall_trace_enter(struct pt_regs *regs)
 {
 	/* do the secure computing check first */
 	secure_computing(regs->orig_rax);

 	if (test_thread_flag(TIF_SYSCALL_TRACE)
 	    && (current->ptrace & PT_PTRACED))
 		syscall_trace(regs);

 	if (unlikely(current->audit_context)) {
 		if (test_thread_flag(TIF_IA32)) {
 			audit_syscall_entry(AUDIT_ARCH_I386,
 					    regs->orig_rax,
 					    regs->rbx, regs->rcx,
 					    regs->rdx, regs->rsi);
 		} else {
 			audit_syscall_entry(AUDIT_ARCH_X86_64,
 					    regs->orig_rax,
 					    regs->rdi, regs->rsi,
 					    regs->rdx, regs->r10);
 		}
 	}
 }

 asmlinkage void syscall_trace_leave(struct pt_regs *regs)
 {
 	if (unlikely(current->audit_context))
 		audit_syscall_exit(AUDITSC_RESULT(regs->rax), regs->rax);

 	if ((test_thread_flag(TIF_SYSCALL_TRACE)
 	     || test_thread_flag(TIF_SINGLESTEP))
 	    && (current->ptrace & PT_PTRACED))
 		syscall_trace(regs);
 }
	/* By Ross Biro 1/23/92 */
	/*
	* Pentium III FXSR, SSE support
	* Gareth Hughes <gareth@valinux.com>, May 2000
	*
	* x86-64 port 2000-2002 Andi Kleen
	*/

	#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/audit.h>
	#include <linux/seccomp.h>
	#include <linux/signal.h>

	#include <asm/uaccess.h>
	#include <asm/pgtable.h>
	#include <asm/system.h>
	#include <asm/processor.h>
	#include <asm/prctl.h>
	#include <asm/i387.h>
	#include <asm/debugreg.h>
	#include <asm/ldt.h>
	#include <asm/desc.h>
	#include <asm/proto.h>
	#include <asm/ia32.h>

	/*
	* does not yet catch signals sent when the child dies.
	* in exit.c or in signal.c.
	*/

	/*
	* Determines which flags the user has access to [1 = access, 0 = no access].
	* Prohibits changing ID(21), VIP(20), VIF(19), VM(17), IOPL(12-13), IF(9).
	* Also masks reserved bits (63-22, 15, 5, 3, 1).
	*/
	#define FLAG_MASK 0x54dd5UL

	/*
	* Called by kernel/ptrace.c when detaching..
	*
	* Make sure the single step bit is not set.
	*/
	void ptrace_disable(struct task_struct *child)
	{
	user_disable_single_step(child);
	}

	static unsigned long pt_regs_access(struct pt_regs regs, unsigned long offset)
	{
	BUILD_BUG_ON(offsetof(struct pt_regs, r15) != 0);
	return &regs->r15 + (offset / sizeof(regs->r15));
	}

	static int putreg(struct task_struct *child,
	unsigned long regno, unsigned long value)
	{
	struct pt_regs *regs = task_pt_regs(child);
	switch (regno) {
	case offsetof(struct user_regs_struct,fs):
	if (value && (value & 3) != 3)
	return -EIO;
	child->thread.fsindex = value & 0xffff;
	return 0;
	case offsetof(struct user_regs_struct,gs):
	if (value && (value & 3) != 3)
	return -EIO;
	child->thread.gsindex = value & 0xffff;
	return 0;
	case offsetof(struct user_regs_struct,ds):
	if (value && (value & 3) != 3)
	return -EIO;
	child->thread.ds = value & 0xffff;
	return 0;
	case offsetof(struct user_regs_struct,es):
	if (value && (value & 3) != 3)
	return -EIO;
	child->thread.es = value & 0xffff;
	return 0;
	case offsetof(struct user_regs_struct,ss):
	if ((value & 3) != 3)
	return -EIO;
	value &= 0xffff;
	return 0;
	case offsetof(struct user_regs_struct,fs_base):
	if (value >= TASK_SIZE_OF(child))
	return -EIO;
	/*
	* When changing the segment base, use do_arch_prctl
	* to set either thread.fs or thread.fsindex and the
	* corresponding GDT slot.
	*/
	if (child->thread.fs != value)
	return do_arch_prctl(child, ARCH_SET_FS, value);
	return 0;
	case offsetof(struct user_regs_struct,gs_base):
	/*
	* Exactly the same here as the %fs handling above.
	*/
	if (value >= TASK_SIZE_OF(child))
	return -EIO;
	if (child->thread.gs != value)
	return do_arch_prctl(child, ARCH_SET_GS, value);
	return 0;
	case offsetof(struct user_regs_struct, eflags):
	value &= FLAG_MASK;
	/*
	* If the user value contains TF, mark that
	* it was not "us" (the debugger) that set it.
	* If not, make sure it stays set if we had.
	*/
	if (value & X86_EFLAGS_TF)
	clear_tsk_thread_flag(child, TIF_FORCED_TF);
	else if (test_tsk_thread_flag(child, TIF_FORCED_TF))
	value \|= X86_EFLAGS_TF;
	value \|= regs->eflags & ~FLAG_MASK;
	break;
	case offsetof(struct user_regs_struct,cs):
	if ((value & 3) != 3)
	return -EIO;
	value &= 0xffff;
	break;
	}
	*pt_regs_access(regs, regno) = value;
	return 0;
	}

	static unsigned long getreg(struct task_struct *child, unsigned long regno)
	{
	struct pt_regs *regs = task_pt_regs(child);
	unsigned long val;
	switch (regno) {
	case offsetof(struct user_regs_struct, fs):
	return child->thread.fsindex;
	case offsetof(struct user_regs_struct, gs):
	return child->thread.gsindex;
	case offsetof(struct user_regs_struct, ds):
	return child->thread.ds;
	case offsetof(struct user_regs_struct, es):
	return child->thread.es;
	case offsetof(struct user_regs_struct, fs_base):
	/*
	* do_arch_prctl may have used a GDT slot instead of
	* the MSR. To userland, it appears the same either
	* way, except the %fs segment selector might not be 0.
	*/
	if (child->thread.fs != 0)
	return child->thread.fs;
	if (child->thread.fsindex != FS_TLS_SEL)
	return 0;
	return get_desc_base(&child->thread.tls_array[FS_TLS]);
	case offsetof(struct user_regs_struct, gs_base):
	/*
	* Exactly the same here as the %fs handling above.
	*/
	if (child->thread.gs != 0)
	return child->thread.gs;
	if (child->thread.gsindex != GS_TLS_SEL)
	return 0;
	return get_desc_base(&child->thread.tls_array[GS_TLS]);
	case offsetof(struct user_regs_struct, eflags):
	/*
	* If the debugger set TF, hide it from the readout.
	*/
	val = regs->eflags;
	if (test_tsk_thread_flag(child, TIF_IA32))
	val &= 0xffffffff;
	if (test_tsk_thread_flag(child, TIF_FORCED_TF))
	val &= ~X86_EFLAGS_TF;
	return val;
	default:
	val = *pt_regs_access(regs, regno);
	if (test_tsk_thread_flag(child, TIF_IA32))
	val &= 0xffffffff;
	return val;
	}

	}

	unsigned long ptrace_get_debugreg(struct task_struct *child, int n)
	{
	switch (n) {
	case 0: return child->thread.debugreg0;
	case 1: return child->thread.debugreg1;
	case 2: return child->thread.debugreg2;
	case 3: return child->thread.debugreg3;
	case 6: return child->thread.debugreg6;
	case 7: return child->thread.debugreg7;
	}
	return 0;
	}

	int ptrace_set_debugreg(struct task_struct *child, int n, unsigned long data)
	{
	int i;

	if (n < 4) {
	int dsize = test_tsk_thread_flag(child, TIF_IA32) ? 3 : 7;
	if (unlikely(data >= TASK_SIZE_OF(child) - dsize))
	return -EIO;
	}

	switch (n) {
	case 0: child->thread.debugreg0 = data; break;
	case 1: child->thread.debugreg1 = data; break;
	case 2: child->thread.debugreg2 = data; break;
	case 3: child->thread.debugreg3 = data; break;

	case 6:
	if (data >> 32)
	return -EIO;
	child->thread.debugreg6 = data;
	break;

	case 7:
	/*
	* See ptrace_32.c for an explanation of this awkward check.
	*/
	data &= ~DR_CONTROL_RESERVED;
	for (i = 0; i < 4; i++)
	if ((0x5554 >> ((data >> (16 + 4*i)) & 0xf)) & 1)
	return -EIO;
	child->thread.debugreg7 = data;
	if (data)
	set_tsk_thread_flag(child, TIF_DEBUG);
	else
	clear_tsk_thread_flag(child, TIF_DEBUG);
	break;
	}

	return 0;
	}

	long arch_ptrace(struct task_struct *child, long request, long addr, long data)
	{
	long ret;
	unsigned ui;

	switch (request) {
	/* when I and D space are separate, these will need to be fixed. */
	case PTRACE_PEEKTEXT: /* read word at location addr. */
	case PTRACE_PEEKDATA:
	ret = generic_ptrace_peekdata(child, addr, data);
	break;

	/* read the word at location addr in the USER area. */
	case PTRACE_PEEKUSR: {
	unsigned long tmp;

	ret = -EIO;
	if ((addr & 7) \|\|
	addr > sizeof(struct user) - 7)
	break;

	tmp = 0;
	if (addr < sizeof(struct user_regs_struct))
	tmp = getreg(child, addr);
	else if (addr >= offsetof(struct user, u_debugreg[0])) {
	addr -= offsetof(struct user, u_debugreg[0]);
	tmp = ptrace_get_debugreg(child, addr / sizeof(long));
	}

	ret = put_user(tmp,(unsigned long __user *) data);
	break;
	}

	/* when I and D space are separate, this will have to be fixed. */
	case PTRACE_POKETEXT: /* write the word at location addr. */
	case PTRACE_POKEDATA:
	ret = generic_ptrace_pokedata(child, addr, data);
	break;

	case PTRACE_POKEUSR: /* write the word at location addr in the USER area */
	ret = -EIO;
	if ((addr & 7) \|\|
	addr > sizeof(struct user) - 7)
	break;

	if (addr < sizeof(struct user_regs_struct))
	ret = putreg(child, addr, data);
	else if (addr >= offsetof(struct user, u_debugreg[0])) {
	addr -= offsetof(struct user, u_debugreg[0]);
	ret = ptrace_set_debugreg(child,
	addr / sizeof(long), data);
	}
	break;

	#ifdef CONFIG_IA32_EMULATION
	/* This makes only sense with 32bit programs. Allow a
	64bit debugger to fully examine them too. Better
	don't use it against 64bit processes, use
	PTRACE_ARCH_PRCTL instead. */
	case PTRACE_GET_THREAD_AREA:
	if (addr < 0)
	return -EIO;
	ret = do_get_thread_area(child, addr,
	(struct user_desc __user *) data);

	break;
	case PTRACE_SET_THREAD_AREA:
	if (addr < 0)
	return -EIO;
	ret = do_set_thread_area(child, addr,
	(struct user_desc __user *) data, 0);
	break;
	#endif
	/* normal 64bit interface to access TLS data.
	Works just like arch_prctl, except that the arguments
	are reversed. */
	case PTRACE_ARCH_PRCTL:
	ret = do_arch_prctl(child, data, addr);
	break;

	case PTRACE_GETREGS: { /* Get all gp regs from the child. */
	if (!access_ok(VERIFY_WRITE, (unsigned __user *)data,
	sizeof(struct user_regs_struct))) {
	ret = -EIO;
	break;
	}
	ret = 0;
	for (ui = 0; ui < sizeof(struct user_regs_struct); ui += sizeof(long)) {
	ret \|= __put_user(getreg(child, ui),(unsigned long __user *) data);
	data += sizeof(long);
	}
	break;
	}

	case PTRACE_SETREGS: { /* Set all gp regs in the child. */
	unsigned long tmp;
	if (!access_ok(VERIFY_READ, (unsigned __user *)data,
	sizeof(struct user_regs_struct))) {
	ret = -EIO;
	break;
	}
	ret = 0;
	for (ui = 0; ui < sizeof(struct user_regs_struct); ui += sizeof(long)) {
	ret = __get_user(tmp, (unsigned long __user *) data);
	if (ret)
	break;
	ret = putreg(child, ui, tmp);
	if (ret)
	break;
	data += sizeof(long);
	}
	break;
	}

	case PTRACE_GETFPREGS: { /* Get the child extended FPU state. */
	if (!access_ok(VERIFY_WRITE, (unsigned __user *)data,
	sizeof(struct user_i387_struct))) {
	ret = -EIO;
	break;
	}
	ret = get_fpregs((struct user_i387_struct __user *)data, child);
	break;
	}

	case PTRACE_SETFPREGS: { /* Set the child extended FPU state. */
	if (!access_ok(VERIFY_READ, (unsigned __user *)data,
	sizeof(struct user_i387_struct))) {
	ret = -EIO;
	break;
	}
	set_stopped_child_used_math(child);
	ret = set_fpregs(child, (struct user_i387_struct __user *)data);
	break;
	}

	default:
	ret = ptrace_request(child, request, addr, data);
	break;
	}
	return ret;
	}

	static void syscall_trace(struct pt_regs *regs)
	{

	#if 0
	printk("trace %s rip %lx rsp %lx rax %d origrax %d caller %lx tiflags %x ptrace %x\n",
	current->comm,
	regs->rip, regs->rsp, regs->rax, regs->orig_rax, __builtin_return_address(0),
	current_thread_info()->flags, current->ptrace);
	#endif

	ptrace_notify(SIGTRAP \| ((current->ptrace & PT_TRACESYSGOOD)
	? 0x80 : 0));
	/*
	* this isn't the same as continuing with a signal, but it will do
	* for normal use. strace only continues with a signal if the
	* stopping signal is not SIGTRAP. -brl
	*/
	if (current->exit_code) {
	send_sig(current->exit_code, current, 1);
	current->exit_code = 0;
	}
	}

	asmlinkage void syscall_trace_enter(struct pt_regs *regs)
	{
	/* do the secure computing check first */
	secure_computing(regs->orig_rax);

	if (test_thread_flag(TIF_SYSCALL_TRACE)
	&& (current->ptrace & PT_PTRACED))
	syscall_trace(regs);

	if (unlikely(current->audit_context)) {
	if (test_thread_flag(TIF_IA32)) {
	audit_syscall_entry(AUDIT_ARCH_I386,
	regs->orig_rax,
	regs->rbx, regs->rcx,
	regs->rdx, regs->rsi);
	} else {
	audit_syscall_entry(AUDIT_ARCH_X86_64,
	regs->orig_rax,
	regs->rdi, regs->rsi,
	regs->rdx, regs->r10);
	}
	}
	}

	asmlinkage void syscall_trace_leave(struct pt_regs *regs)
	{
	if (unlikely(current->audit_context))
	audit_syscall_exit(AUDITSC_RESULT(regs->rax), regs->rax);

	if ((test_thread_flag(TIF_SYSCALL_TRACE)
	\|\| test_thread_flag(TIF_SINGLESTEP))
	&& (current->ptrace & PT_PTRACED))
	syscall_trace(regs);
	}