[deliverable/linux.git] / arch / x86 / kernel / ptrace_32.c

/* By Ross Biro 1/23/92 */
/*
 * Pentium III FXSR, SSE support
 *	Gareth Hughes <gareth@valinux.com>, May 2000
 */

#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/i387.h>
#include <asm/debugreg.h>
#include <asm/ldt.h>
#include <asm/desc.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), NT(14), IOPL(12-13), IF(9).
 * Also masks reserved bits (31-22, 15, 5, 3, 1).
 */
#define FLAG_MASK 0x00050dd5

static long *pt_regs_access(struct pt_regs *regs, unsigned long regno)
{
	BUILD_BUG_ON(offsetof(struct pt_regs, bx) != 0);
	if (regno > FS)
		--regno;
	return &regs->bx + regno;
}

static int putreg(struct task_struct *child,
	unsigned long regno, unsigned long value)
{
	struct pt_regs *regs = task_pt_regs(child);
	regno >>= 2;
	switch (regno) {
		case GS:
			if (value && (value & 3) != 3)
				return -EIO;
			child->thread.gs = value;
			return 0;
		case DS:
		case ES:
		case FS:
			if (value && (value & 3) != 3)
				return -EIO;
			value &= 0xffff;
			break;
		case SS:
		case CS:
			if ((value & 3) != 3)
				return -EIO;
			value &= 0xffff;
			break;
		case EFL:
			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->flags & ~FLAG_MASK;
			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 retval = ~0UL;

	regno >>= 2;
	switch (regno) {
		case EFL:
			/*
			 * If the debugger set TF, hide it from the readout.
			 */
			retval = regs->flags;
			if (test_tsk_thread_flag(child, TIF_FORCED_TF))
				retval &= ~X86_EFLAGS_TF;
			break;
		case GS:
			retval = child->thread.gs;
			break;
		case DS:
		case ES:
		case FS:
		case SS:
		case CS:
			retval = 0xffff;
			/* fall through */
		default:
			retval &= *pt_regs_access(regs, regno);
	}
	return retval;
}

/*
 * This function is trivial and will be inlined by the compiler.
 * Having it separates the implementation details of debug
 * registers from the interface details of ptrace.
 */
static unsigned long ptrace_get_debugreg(struct task_struct *child, int n)
{
	return child->thread.debugreg[n];
}

static int ptrace_set_debugreg(struct task_struct *child,
			       int n, unsigned long data)
{
	if (unlikely(n == 4 || n == 5))
		return -EIO;

	if (n < 4 && unlikely(data >= TASK_SIZE - 3))
		return -EIO;

	if (n == 7) {
		/*
		 * Sanity-check data. Take one half-byte at once with
		 * check = (val >> (16 + 4*i)) & 0xf. It contains the
		 * R/Wi and LENi bits; bits 0 and 1 are R/Wi, and bits
		 * 2 and 3 are LENi. Given a list of invalid values,
		 * we do mask |= 1 << invalid_value, so that
		 * (mask >> check) & 1 is a correct test for invalid
		 * values.
		 *
		 * R/Wi contains the type of the breakpoint /
		 * watchpoint, LENi contains the length of the watched
		 * data in the watchpoint case.
		 *
		 * The invalid values are:
		 * - LENi == 0x10 (undefined), so mask |= 0x0f00.
		 * - R/Wi == 0x10 (break on I/O reads or writes), so
		 *   mask |= 0x4444.
		 * - R/Wi == 0x00 && LENi != 0x00, so we have mask |=
		 *   0x1110.
		 *
		 * Finally, mask = 0x0f00 | 0x4444 | 0x1110 == 0x5f54.
		 *
		 * See the Intel Manual "System Programming Guide",
		 * 15.2.4
		 *
		 * Note that LENi == 0x10 is defined on x86_64 in long
		 * mode (i.e. even for 32-bit userspace software, but
		 * 64-bit kernel), so the x86_64 mask value is 0x5454.
		 * See the AMD manual no. 24593 (AMD64 System Programming)
		 */
		int i;
		data &= ~DR_CONTROL_RESERVED;
		for (i = 0; i < 4; i++)
			if ((0x5f54 >> ((data >> (16 + 4*i)) & 0xf)) & 1)
				return -EIO;
		if (data)
			set_tsk_thread_flag(child, TIF_DEBUG);
		else
			clear_tsk_thread_flag(child, TIF_DEBUG);
	}

	child->thread.debugreg[n] = data;

	return 0;
}

/*
 * 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);
	clear_tsk_thread_flag(child, TIF_SYSCALL_EMU);
}

long arch_ptrace(struct task_struct *child, long request, long addr, long data)
{
	struct user * dummy = NULL;
	int i, ret;
	unsigned long __user *datap = (unsigned long __user *)data;

	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 & 3) || addr < 0 || 
		    addr > sizeof(struct user) - 3)
			break;

		tmp = 0;  /* Default return condition */
		if(addr < FRAME_SIZE*sizeof(long))
			tmp = getreg(child, addr);
		if(addr >= (long) &dummy->u_debugreg[0] &&
		   addr <= (long) &dummy->u_debugreg[7]){
			addr -= (long) &dummy->u_debugreg[0];
			addr = addr >> 2;
			tmp = ptrace_get_debugreg(child, addr);
		}
		ret = put_user(tmp, datap);
		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 & 3) || addr < 0 || 
		    addr > sizeof(struct user) - 3)
			break;

		if (addr < FRAME_SIZE*sizeof(long)) {
			ret = putreg(child, addr, data);
			break;
		}
		/* We need to be very careful here.  We implicitly
		   want to modify a portion of the task_struct, and we
		   have to be selective about what portions we allow someone
		   to modify. */

		  ret = -EIO;
		  if(addr >= (long) &dummy->u_debugreg[0] &&
		     addr <= (long) &dummy->u_debugreg[7]){
			  addr -= (long) &dummy->u_debugreg;
			  addr = addr >> 2;
			  ret = ptrace_set_debugreg(child, addr, data);
		  }
		  break;

	case PTRACE_GETREGS: { /* Get all gp regs from the child. */
	  	if (!access_ok(VERIFY_WRITE, datap, FRAME_SIZE*sizeof(long))) {
			ret = -EIO;
			break;
		}
		for ( i = 0; i < FRAME_SIZE*sizeof(long); i += sizeof(long) ) {
			__put_user(getreg(child, i), datap);
			datap++;
		}
		ret = 0;
		break;
	}

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

	case PTRACE_GETFPREGS: { /* Get the child FPU state. */
		if (!access_ok(VERIFY_WRITE, datap,
			       sizeof(struct user_i387_struct))) {
			ret = -EIO;
			break;
		}
		ret = 0;
		if (!tsk_used_math(child))
			init_fpu(child);
		get_fpregs((struct user_i387_struct __user *)data, child);
		break;
	}

	case PTRACE_SETFPREGS: { /* Set the child FPU state. */
		if (!access_ok(VERIFY_READ, datap,
			       sizeof(struct user_i387_struct))) {
			ret = -EIO;
			break;
		}
		set_stopped_child_used_math(child);
		set_fpregs(child, (struct user_i387_struct __user *)data);
		ret = 0;
		break;
	}

	case PTRACE_GETFPXREGS: { /* Get the child extended FPU state. */
		if (!access_ok(VERIFY_WRITE, datap,
			       sizeof(struct user_fxsr_struct))) {
			ret = -EIO;
			break;
		}
		if (!tsk_used_math(child))
			init_fpu(child);
		ret = get_fpxregs((struct user_fxsr_struct __user *)data, child);
		break;
	}

	case PTRACE_SETFPXREGS: { /* Set the child extended FPU state. */
		if (!access_ok(VERIFY_READ, datap,
			       sizeof(struct user_fxsr_struct))) {
			ret = -EIO;
			break;
		}
		set_stopped_child_used_math(child);
		ret = set_fpxregs(child, (struct user_fxsr_struct __user *)data);
		break;
	}

	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;

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

	return ret;
}

void send_sigtrap(struct task_struct *tsk, struct pt_regs *regs, int error_code)
{
	struct siginfo info;

	tsk->thread.trap_no = 1;
	tsk->thread.error_code = error_code;

	memset(&info, 0, sizeof(info));
	info.si_signo = SIGTRAP;
	info.si_code = TRAP_BRKPT;

	/* User-mode ip? */
	info.si_addr = user_mode_vm(regs) ? (void __user *) regs->ip : NULL;

	/* Send us the fake SIGTRAP */
	force_sig_info(SIGTRAP, &info, tsk);
}

/* notification of system call entry/exit
 * - triggered by current->work.syscall_trace
 */
__attribute__((regparm(3)))
int do_syscall_trace(struct pt_regs *regs, int entryexit)
{
	int is_sysemu = test_thread_flag(TIF_SYSCALL_EMU);
	/*
	 * With TIF_SYSCALL_EMU set we want to ignore TIF_SINGLESTEP for syscall
	 * interception
	 */
	int is_singlestep = !is_sysemu && test_thread_flag(TIF_SINGLESTEP);
	int ret = 0;

	/* do the secure computing check first */
	if (!entryexit)
		secure_computing(regs->orig_ax);

	if (unlikely(current->audit_context)) {
		if (entryexit)
			audit_syscall_exit(AUDITSC_RESULT(regs->ax),
						regs->ax);
		/* Debug traps, when using PTRACE_SINGLESTEP, must be sent only
		 * on the syscall exit path. Normally, when TIF_SYSCALL_AUDIT is
		 * not used, entry.S will call us only on syscall exit, not
		 * entry; so when TIF_SYSCALL_AUDIT is used we must avoid
		 * calling send_sigtrap() on syscall entry.
		 *
		 * Note that when PTRACE_SYSEMU_SINGLESTEP is used,
		 * is_singlestep is false, despite his name, so we will still do
		 * the correct thing.
		 */
		else if (is_singlestep)
			goto out;
	}

	if (!(current->ptrace & PT_PTRACED))
		goto out;

	/* If a process stops on the 1st tracepoint with SYSCALL_TRACE
	 * and then is resumed with SYSEMU_SINGLESTEP, it will come in
	 * here. We have to check this and return */
	if (is_sysemu && entryexit)
		return 0;

	/* Fake a debug trap */
	if (is_singlestep)
		send_sigtrap(current, regs, 0);

 	if (!test_thread_flag(TIF_SYSCALL_TRACE) && !is_sysemu)
		goto out;

	/* the 0x80 provides a way for the tracing parent to distinguish
	   between a syscall stop and SIGTRAP delivery */
	/* Note that the debugger could change the result of test_thread_flag!*/
	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;
	}
	ret = is_sysemu;
out:
	if (unlikely(current->audit_context) && !entryexit)
		audit_syscall_entry(AUDIT_ARCH_I386, regs->orig_ax,
				    regs->bx, regs->cx, regs->dx, regs->si);
	if (ret == 0)
		return 0;

	regs->orig_ax = -1; /* force skip of syscall restarting */
	if (unlikely(current->audit_context))
		audit_syscall_exit(AUDITSC_RESULT(regs->ax), regs->ax);
	return 1;
}
Commit	Line	Data
1da177e4 LT	1	/* By Ross Biro 1/23/92 */
	2	/*
	3	* Pentium III FXSR, SSE support
	4	* Gareth Hughes <gareth@valinux.com>, May 2000
	5	*/
	6
	7	#include <linux/kernel.h>
	8	#include <linux/sched.h>
	9	#include <linux/mm.h>
	10	#include <linux/smp.h>
1da177e4 LT	11	#include <linux/errno.h>
	12	#include <linux/ptrace.h>
	13	#include <linux/user.h>
	14	#include <linux/security.h>
	15	#include <linux/audit.h>
	16	#include <linux/seccomp.h>
7ed20e1a	17	#include <linux/signal.h>
1da177e4 LT	18
	19	#include <asm/uaccess.h>
	20	#include <asm/pgtable.h>
	21	#include <asm/system.h>
	22	#include <asm/processor.h>
	23	#include <asm/i387.h>
	24	#include <asm/debugreg.h>
	25	#include <asm/ldt.h>
	26	#include <asm/desc.h>
	27
	28	/*
	29	* does not yet catch signals sent when the child dies.
	30	* in exit.c or in signal.c.
	31	*/
	32
9f155b98 CE	33	/*
9f155b98 CE	34	* Determines which flags the user has access to [1 = access, 0 = no access].
3c36c6aa	35	* Prohibits changing ID(21), VIP(20), VIF(19), VM(17), NT(14), IOPL(12-13), IF(9).
9f155b98 CE	36	* Also masks reserved bits (31-22, 15, 5, 3, 1).
9f155b98 CE	37	*/
3c36c6aa	38	#define FLAG_MASK 0x00050dd5
1da177e4	39
62a97d44	40	static long pt_regs_access(struct pt_regs regs, unsigned long regno)
1da177e4	41	{
65ea5b03	42	BUILD_BUG_ON(offsetof(struct pt_regs, bx) != 0);
62a97d44 RM	43	if (regno > FS)
62a97d44 RM	44	--regno;
65ea5b03	45	return &regs->bx + regno;
1da177e4 LT	46	}
	47
	48	static int putreg(struct task_struct *child,
	49	unsigned long regno, unsigned long value)
	50	{
62a97d44 RM	51	struct pt_regs *regs = task_pt_regs(child);
	52	regno >>= 2;
	53	switch (regno) {
464d1a78	54	case GS:
1da177e4 LT	55	if (value && (value & 3) != 3)
1da177e4 LT	56	return -EIO;
464d1a78	57	child->thread.gs = value;
1da177e4	58	return 0;
1da177e4 LT	59	case DS:
1da177e4 LT	60	case ES:
464d1a78	61	case FS:
1da177e4 LT	62	if (value && (value & 3) != 3)
	63	return -EIO;
	64	value &= 0xffff;
	65	break;
	66	case SS:
	67	case CS:
	68	if ((value & 3) != 3)
	69	return -EIO;
	70	value &= 0xffff;
	71	break;
	72	case EFL:
	73	value &= FLAG_MASK;
e1f28773 RM	74	/*
	75	* If the user value contains TF, mark that
	76	* it was not "us" (the debugger) that set it.
	77	* If not, make sure it stays set if we had.
	78	*/
	79	if (value & X86_EFLAGS_TF)
	80	clear_tsk_thread_flag(child, TIF_FORCED_TF);
	81	else if (test_tsk_thread_flag(child, TIF_FORCED_TF))
	82	value \|= X86_EFLAGS_TF;
65ea5b03	83	value \|= regs->flags & ~FLAG_MASK;
1da177e4 LT	84	break;
1da177e4 LT	85	}
62a97d44	86	*pt_regs_access(regs, regno) = value;
1da177e4 LT	87	return 0;
	88	}
	89
62a97d44	90	static unsigned long getreg(struct task_struct *child, unsigned long regno)
1da177e4	91	{
62a97d44	92	struct pt_regs *regs = task_pt_regs(child);
1da177e4 LT	93	unsigned long retval = ~0UL;
1da177e4 LT	94
62a97d44 RM	95	regno >>= 2;
62a97d44 RM	96	switch (regno) {
e1f28773 RM	97	case EFL:
	98	/*
	99	* If the debugger set TF, hide it from the readout.
	100	*/
65ea5b03	101	retval = regs->flags;
e1f28773 RM	102	if (test_tsk_thread_flag(child, TIF_FORCED_TF))
	103	retval &= ~X86_EFLAGS_TF;
	104	break;
464d1a78 JF	105	case GS:
464d1a78 JF	106	retval = child->thread.gs;
1da177e4	107	break;
1da177e4 LT	108	case DS:
1da177e4 LT	109	case ES:
464d1a78	110	case FS:
1da177e4 LT	111	case SS:
	112	case CS:
	113	retval = 0xffff;
	114	/* fall through */
	115	default:
62a97d44	116	retval &= *pt_regs_access(regs, regno);
1da177e4 LT	117	}
	118	return retval;
	119	}
	120
d9771e8c RM	121	/*
	122	* This function is trivial and will be inlined by the compiler.
	123	* Having it separates the implementation details of debug
	124	* registers from the interface details of ptrace.
	125	*/
	126	static unsigned long ptrace_get_debugreg(struct task_struct *child, int n)
	127	{
	128	return child->thread.debugreg[n];
	129	}
	130
	131	static int ptrace_set_debugreg(struct task_struct *child,
	132	int n, unsigned long data)
	133	{
	134	if (unlikely(n == 4 \|\| n == 5))
	135	return -EIO;
	136
	137	if (n < 4 && unlikely(data >= TASK_SIZE - 3))
	138	return -EIO;
	139
	140	if (n == 7) {
	141	/*
	142	* Sanity-check data. Take one half-byte at once with
	143	* check = (val >> (16 + 4*i)) & 0xf. It contains the
	144	* R/Wi and LENi bits; bits 0 and 1 are R/Wi, and bits
	145	* 2 and 3 are LENi. Given a list of invalid values,
	146	* we do mask \|= 1 << invalid_value, so that
	147	* (mask >> check) & 1 is a correct test for invalid
	148	* values.
	149	*
	150	* R/Wi contains the type of the breakpoint /
	151	* watchpoint, LENi contains the length of the watched
	152	* data in the watchpoint case.
	153	*
	154	* The invalid values are:
	155	* - LENi == 0x10 (undefined), so mask \|= 0x0f00.
	156	* - R/Wi == 0x10 (break on I/O reads or writes), so
	157	* mask \|= 0x4444.
	158	* - R/Wi == 0x00 && LENi != 0x00, so we have mask \|=
	159	* 0x1110.
	160	*
	161	* Finally, mask = 0x0f00 \| 0x4444 \| 0x1110 == 0x5f54.
	162	*
	163	* See the Intel Manual "System Programming Guide",
	164	* 15.2.4
	165	*
	166	* Note that LENi == 0x10 is defined on x86_64 in long
	167	* mode (i.e. even for 32-bit userspace software, but
	168	* 64-bit kernel), so the x86_64 mask value is 0x5454.
	169	* See the AMD manual no. 24593 (AMD64 System Programming)
	170	*/
	171	int i;
	172	data &= ~DR_CONTROL_RESERVED;
	173	for (i = 0; i < 4; i++)
	174	if ((0x5f54 >> ((data >> (16 + 4*i)) & 0xf)) & 1)
	175	return -EIO;
	176	if (data)
	177	set_tsk_thread_flag(child, TIF_DEBUG);
	178	else
	179	clear_tsk_thread_flag(child, TIF_DEBUG);
	180	}
	181
	182	child->thread.debugreg[n] = data;
	183
	184	return 0;
185	}
186
1da177e4 LT	187	/*
	188	* Called by kernel/ptrace.c when detaching..
	189	*
	190	* Make sure the single step bit is not set.
	191	*/
	192	void ptrace_disable(struct task_struct *child)
	193	{
7f232343	194	user_disable_single_step(child);
ab1c23c2	195	clear_tsk_thread_flag(child, TIF_SYSCALL_EMU);
1da177e4 LT	196	}
1da177e4 LT	197
481bed45	198	long arch_ptrace(struct task_struct *child, long request, long addr, long data)
1da177e4	199	{
1da177e4 LT	200	struct user * dummy = NULL;
	201	int i, ret;
	202	unsigned long __user datap = (unsigned long __user )data;
	203
1da177e4 LT	204	switch (request) {
	205	/* when I and D space are separate, these will need to be fixed. */
	206	case PTRACE_PEEKTEXT: /* read word at location addr. */
76647323 AD	207	case PTRACE_PEEKDATA:
76647323 AD	208	ret = generic_ptrace_peekdata(child, addr, data);
1da177e4	209	break;
1da177e4 LT	210
	211	/* read the word at location addr in the USER area. */
	212	case PTRACE_PEEKUSR: {
	213	unsigned long tmp;
	214
	215	ret = -EIO;
	216	if ((addr & 3) \|\| addr < 0 \|\|
	217	addr > sizeof(struct user) - 3)
	218	break;
	219
	220	tmp = 0; /* Default return condition */
	221	if(addr < FRAME_SIZE*sizeof(long))
	222	tmp = getreg(child, addr);
	223	if(addr >= (long) &dummy->u_debugreg[0] &&
	224	addr <= (long) &dummy->u_debugreg[7]){
	225	addr -= (long) &dummy->u_debugreg[0];
	226	addr = addr >> 2;
d9771e8c	227	tmp = ptrace_get_debugreg(child, addr);
1da177e4 LT	228	}
	229	ret = put_user(tmp, datap);
	230	break;
	231	}
	232
	233	/* when I and D space are separate, this will have to be fixed. */
	234	case PTRACE_POKETEXT: /* write the word at location addr. */
	235	case PTRACE_POKEDATA:
f284ce72	236	ret = generic_ptrace_pokedata(child, addr, data);
1da177e4 LT	237	break;
	238
	239	case PTRACE_POKEUSR: /* write the word at location addr in the USER area */
	240	ret = -EIO;
	241	if ((addr & 3) \|\| addr < 0 \|\|
	242	addr > sizeof(struct user) - 3)
	243	break;
	244
	245	if (addr < FRAME_SIZE*sizeof(long)) {
	246	ret = putreg(child, addr, data);
	247	break;
	248	}
	249	/* We need to be very careful here. We implicitly
	250	want to modify a portion of the task_struct, and we
	251	have to be selective about what portions we allow someone
	252	to modify. */
	253
	254	ret = -EIO;
	255	if(addr >= (long) &dummy->u_debugreg[0] &&
	256	addr <= (long) &dummy->u_debugreg[7]){
1da177e4 LT	257	addr -= (long) &dummy->u_debugreg;
1da177e4 LT	258	addr = addr >> 2;
d9771e8c	259	ret = ptrace_set_debugreg(child, addr, data);
1da177e4 LT	260	}
	261	break;
	262
1da177e4 LT	263	case PTRACE_GETREGS: { /* Get all gp regs from the child. */
	264	if (!access_ok(VERIFY_WRITE, datap, FRAME_SIZE*sizeof(long))) {
	265	ret = -EIO;
	266	break;
	267	}
	268	for ( i = 0; i < FRAME_SIZE*sizeof(long); i += sizeof(long) ) {
	269	__put_user(getreg(child, i), datap);
	270	datap++;
	271	}
	272	ret = 0;
	273	break;
	274	}
	275
	276	case PTRACE_SETREGS: { /* Set all gp regs in the child. */
	277	unsigned long tmp;
	278	if (!access_ok(VERIFY_READ, datap, FRAME_SIZE*sizeof(long))) {
	279	ret = -EIO;
	280	break;
	281	}
	282	for ( i = 0; i < FRAME_SIZE*sizeof(long); i += sizeof(long) ) {
	283	__get_user(tmp, datap);
	284	putreg(child, i, tmp);
	285	datap++;
	286	}
	287	ret = 0;
	288	break;
	289	}
	290
	291	case PTRACE_GETFPREGS: { /* Get the child FPU state. */
	292	if (!access_ok(VERIFY_WRITE, datap,
	293	sizeof(struct user_i387_struct))) {
	294	ret = -EIO;
	295	break;
	296	}
	297	ret = 0;
	298	if (!tsk_used_math(child))
	299	init_fpu(child);
	300	get_fpregs((struct user_i387_struct __user *)data, child);
	301	break;
	302	}
	303
	304	case PTRACE_SETFPREGS: { /* Set the child FPU state. */
	305	if (!access_ok(VERIFY_READ, datap,
	306	sizeof(struct user_i387_struct))) {
	307	ret = -EIO;
	308	break;
	309	}
	310	set_stopped_child_used_math(child);
	311	set_fpregs(child, (struct user_i387_struct __user *)data);
	312	ret = 0;
	313	break;
	314	}
	315
	316	case PTRACE_GETFPXREGS: { /* Get the child extended FPU state. */
	317	if (!access_ok(VERIFY_WRITE, datap,
	318	sizeof(struct user_fxsr_struct))) {
	319	ret = -EIO;
	320	break;
	321	}
	322	if (!tsk_used_math(child))
	323	init_fpu(child);
	324	ret = get_fpxregs((struct user_fxsr_struct __user *)data, child);
	325	break;
	326	}
327
328	case PTRACE_SETFPXREGS: { /* Set the child extended FPU state. */
329	if (!access_ok(VERIFY_READ, datap,
330	sizeof(struct user_fxsr_struct))) {
331	ret = -EIO;
332	break;
333	}
334	set_stopped_child_used_math(child);
335	ret = set_fpxregs(child, (struct user_fxsr_struct __user *)data);
336	break;
337	}
338
339	case PTRACE_GET_THREAD_AREA:
efd1ca52 RM	340	if (addr < 0)
	341	return -EIO;
	342	ret = do_get_thread_area(child, addr,
	343	(struct user_desc __user *) data);
1da177e4 LT	344	break;
	345
	346	case PTRACE_SET_THREAD_AREA:
efd1ca52 RM	347	if (addr < 0)
	348	return -EIO;
	349	ret = do_set_thread_area(child, addr,
	350	(struct user_desc __user *) data, 0);
1da177e4 LT	351	break;
	352
	353	default:
	354	ret = ptrace_request(child, request, addr, data);
	355	break;
	356	}
d9771e8c	357
1da177e4 LT	358	return ret;
	359	}
	360
	361	void send_sigtrap(struct task_struct tsk, struct pt_regs regs, int error_code)
	362	{
	363	struct siginfo info;
	364
	365	tsk->thread.trap_no = 1;
	366	tsk->thread.error_code = error_code;
	367
	368	memset(&info, 0, sizeof(info));
	369	info.si_signo = SIGTRAP;
	370	info.si_code = TRAP_BRKPT;
	371
65ea5b03 PA	372	/* User-mode ip? */
65ea5b03 PA	373	info.si_addr = user_mode_vm(regs) ? (void __user *) regs->ip : NULL;
1da177e4	374
27b46d76	375	/* Send us the fake SIGTRAP */
1da177e4 LT	376	force_sig_info(SIGTRAP, &info, tsk);
	377	}
	378
	379	/* notification of system call entry/exit
	380	* - triggered by current->work.syscall_trace
	381	*/
	382	__attribute__((regparm(3)))
ed75e8d5	383	int do_syscall_trace(struct pt_regs *regs, int entryexit)
1da177e4	384	{
4c7fc722 AA	385	int is_sysemu = test_thread_flag(TIF_SYSCALL_EMU);
	386	/*
	387	* With TIF_SYSCALL_EMU set we want to ignore TIF_SINGLESTEP for syscall
	388	* interception
	389	*/
1b38f006	390	int is_singlestep = !is_sysemu && test_thread_flag(TIF_SINGLESTEP);
4c7fc722	391	int ret = 0;
1b38f006	392
1da177e4	393	/* do the secure computing check first */
4c7fc722	394	if (!entryexit)
65ea5b03	395	secure_computing(regs->orig_ax);
1da177e4	396
ab1c23c2 BS	397	if (unlikely(current->audit_context)) {
ab1c23c2 BS	398	if (entryexit)
65ea5b03 PA	399	audit_syscall_exit(AUDITSC_RESULT(regs->ax),
65ea5b03 PA	400	regs->ax);
ab1c23c2 BS	401	/* Debug traps, when using PTRACE_SINGLESTEP, must be sent only
	402	* on the syscall exit path. Normally, when TIF_SYSCALL_AUDIT is
	403	* not used, entry.S will call us only on syscall exit, not
	404	* entry; so when TIF_SYSCALL_AUDIT is used we must avoid
	405	* calling send_sigtrap() on syscall entry.
	406	*
	407	* Note that when PTRACE_SYSEMU_SINGLESTEP is used,
	408	* is_singlestep is false, despite his name, so we will still do
	409	* the correct thing.
	410	*/
	411	else if (is_singlestep)
	412	goto out;
	413	}
1da177e4 LT	414
1da177e4 LT	415	if (!(current->ptrace & PT_PTRACED))
2fd6f58b	416	goto out;
1da177e4	417
1b38f006 BS	418	/* If a process stops on the 1st tracepoint with SYSCALL_TRACE
	419	* and then is resumed with SYSEMU_SINGLESTEP, it will come in
	420	* here. We have to check this and return */
	421	if (is_sysemu && entryexit)
	422	return 0;
ed75e8d5	423
1da177e4	424	/* Fake a debug trap */
c8c86cec	425	if (is_singlestep)
1da177e4 LT	426	send_sigtrap(current, regs, 0);
1da177e4 LT	427
c8c86cec	428	if (!test_thread_flag(TIF_SYSCALL_TRACE) && !is_sysemu)
2fd6f58b	429	goto out;
1da177e4 LT	430
	431	/* the 0x80 provides a way for the tracing parent to distinguish
	432	between a syscall stop and SIGTRAP delivery */
ed75e8d5	433	/* Note that the debugger could change the result of test_thread_flag!*/
4c7fc722	434	ptrace_notify(SIGTRAP \| ((current->ptrace & PT_TRACESYSGOOD) ? 0x80:0));
1da177e4 LT	435
	436	/*
	437	* this isn't the same as continuing with a signal, but it will do
	438	* for normal use. strace only continues with a signal if the
	439	* stopping signal is not SIGTRAP. -brl
	440	*/
	441	if (current->exit_code) {
	442	send_sig(current->exit_code, current, 1);
	443	current->exit_code = 0;
	444	}
ed75e8d5	445	ret = is_sysemu;
4c7fc722	446	out:
2fd6f58b	447	if (unlikely(current->audit_context) && !entryexit)
65ea5b03 PA	448	audit_syscall_entry(AUDIT_ARCH_I386, regs->orig_ax,
65ea5b03 PA	449	regs->bx, regs->cx, regs->dx, regs->si);
c8c86cec BS	450	if (ret == 0)
	451	return 0;
	452
65ea5b03	453	regs->orig_ax = -1; /* force skip of syscall restarting */
c8c86cec	454	if (unlikely(current->audit_context))
65ea5b03	455	audit_syscall_exit(AUDITSC_RESULT(regs->ax), regs->ax);
c8c86cec	456	return 1;
1da177e4	457	}