[deliverable/linux.git] / 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/config.h>
#include <linux/compiler.h>
#include <linux/kernel.h>
#include <linux/sched.h>
#include <linux/mm.h>
#include <linux/errno.h>
#include <linux/ptrace.h>
#include <linux/audit.h>
#include <linux/smp.h>
#include <linux/smp_lock.h>
#include <linux/user.h>
#include <linux/security.h>
#include <linux/signal.h>

#include <asm/byteorder.h>
#include <asm/cpu.h>
#include <asm/dsp.h>
#include <asm/fpu.h>
#include <asm/mipsregs.h>
#include <asm/pgtable.h>
#include <asm/page.h>
#include <asm/system.h>
#include <asm/uaccess.h>
#include <asm/bootinfo.h>

/*
 * Called by kernel/ptrace.c when detaching..
 *
 * Make sure single step bits etc are not set.
 */
void ptrace_disable(struct task_struct *child)
{
	/* Nothing to do.. */
}

asmlinkage int sys_ptrace(long request, long pid, long addr, long data)
{
	struct task_struct *child;
	int ret;

#if 0
	printk("ptrace(r=%d,pid=%d,addr=%08lx,data=%08lx)\n",
	       (int) request, (int) pid, (unsigned long) addr,
	       (unsigned long) data);
#endif
	lock_kernel();
	ret = -EPERM;
	if (request == PTRACE_TRACEME) {
		/* are we already being traced? */
		if (current->ptrace & PT_PTRACED)
			goto out;
		if ((ret = security_ptrace(current->parent, current)))
			goto out;
		/* set the ptrace bit in the process flags. */
		current->ptrace |= PT_PTRACED;
		ret = 0;
		goto out;
	}
	ret = -ESRCH;
	read_lock(&tasklist_lock);
	child = find_task_by_pid(pid);
	if (child)
		get_task_struct(child);
	read_unlock(&tasklist_lock);
	if (!child)
		goto out;

	ret = -EPERM;
	if (pid == 1)		/* you may not mess with init */
		goto out_tsk;

	if (request == PTRACE_ATTACH) {
		ret = ptrace_attach(child);
		goto out_tsk;
	}

	ret = ptrace_check_attach(child, request == PTRACE_KILL);
	if (ret < 0)
		goto out_tsk;

	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: {
		unsigned long tmp;
		int copied;

		copied = access_process_vm(child, addr, &tmp, sizeof(tmp), 0);
		ret = -EIO;
		if (copied != sizeof(tmp))
			break;
		ret = put_user(tmp,(unsigned long __user *) data);
		break;
	}

	/* Read the word at location addr in the USER area. */
	case PTRACE_PEEKUSR: {
		struct pt_regs *regs;
		unsigned long tmp = 0;

		regs = (struct pt_regs *) ((unsigned long) child->thread_info +
		       THREAD_SIZE - 32 - sizeof(struct pt_regs));
		ret = 0;  /* Default return value. */

		switch (addr) {
		case 0 ... 31:
			tmp = regs->regs[addr];
			break;
		case FPR_BASE ... FPR_BASE + 31:
			if (tsk_used_math(child)) {
				fpureg_t *fregs = get_fpu_regs(child);

#ifdef CONFIG_32BIT
				/*
				 * The odd registers are actually the high
				 * order bits of the values stored in the even
				 * registers - unless we're using r2k_switch.S.
				 */
				if (addr & 1)
					tmp = (unsigned long) (fregs[((addr & ~1) - 32)] >> 32);
				else
					tmp = (unsigned long) (fregs[(addr - 32)] & 0xffffffff);
#endif
#ifdef CONFIG_64BIT
				tmp = fregs[addr - FPR_BASE];
#endif
			} else {
				tmp = -1;	/* FP not yet used  */
			}
			break;
		case PC:
			tmp = regs->cp0_epc;
			break;
		case CAUSE:
			tmp = regs->cp0_cause;
			break;
		case BADVADDR:
			tmp = regs->cp0_badvaddr;
			break;
		case MMHI:
			tmp = regs->hi;
			break;
		case MMLO:
			tmp = regs->lo;
			break;
		case FPC_CSR:
			if (cpu_has_fpu)
				tmp = child->thread.fpu.hard.fcr31;
			else
				tmp = child->thread.fpu.soft.fcr31;
			break;
		case FPC_EIR: {	/* implementation / version register */
			unsigned int flags;

			if (!cpu_has_fpu)
				break;

			flags = read_c0_status();
			__enable_fpu();
			__asm__ __volatile__("cfc1\t%0,$0": "=r" (tmp));
			write_c0_status(flags);
			break;
		}
		case DSP_BASE ... DSP_BASE + 5: {
			dspreg_t *dregs;

			if (!cpu_has_dsp) {
				tmp = 0;
				ret = -EIO;
				goto out_tsk;
			}
			if (child->thread.dsp.used_dsp) {
				dregs = __get_dsp_regs(child);
				tmp = (unsigned long) (dregs[addr - DSP_BASE]);
			} else {
				tmp = -1;	/* DSP registers yet used  */
			}
			break;
		}
		case DSP_CONTROL:
			if (!cpu_has_dsp) {
				tmp = 0;
				ret = -EIO;
				goto out_tsk;
			}
			tmp = child->thread.dsp.dspcontrol;
			break;
		default:
			tmp = 0;
			ret = -EIO;
			goto out_tsk;
		}
		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 = 0;
		if (access_process_vm(child, addr, &data, sizeof(data), 1)
		    == sizeof(data))
			break;
		ret = -EIO;
		break;

	case PTRACE_POKEUSR: {
		struct pt_regs *regs;
		ret = 0;
		regs = (struct pt_regs *) ((unsigned long) child->thread_info +
		       THREAD_SIZE - 32 - sizeof(struct pt_regs));

		switch (addr) {
		case 0 ... 31:
			regs->regs[addr] = data;
			break;
		case FPR_BASE ... FPR_BASE + 31: {
			fpureg_t *fregs = get_fpu_regs(child);

			if (!tsk_used_math(child)) {
				/* FP not yet used  */
				memset(&child->thread.fpu.hard, ~0,
				       sizeof(child->thread.fpu.hard));
				child->thread.fpu.hard.fcr31 = 0;
			}
#ifdef CONFIG_32BIT
			/*
			 * The odd registers are actually the high order bits
			 * of the values stored in the even registers - unless
			 * we're using r2k_switch.S.
			 */
			if (addr & 1) {
				fregs[(addr & ~1) - FPR_BASE] &= 0xffffffff;
				fregs[(addr & ~1) - FPR_BASE] |= ((unsigned long long) data) << 32;
			} else {
				fregs[addr - FPR_BASE] &= ~0xffffffffLL;
				fregs[addr - FPR_BASE] |= data;
			}
#endif
#ifdef CONFIG_64BIT
			fregs[addr - FPR_BASE] = data;
#endif
			break;
		}
		case PC:
			regs->cp0_epc = data;
			break;
		case MMHI:
			regs->hi = data;
			break;
		case MMLO:
			regs->lo = data;
			break;
		case FPC_CSR:
			if (cpu_has_fpu)
				child->thread.fpu.hard.fcr31 = data;
			else
				child->thread.fpu.soft.fcr31 = data;
			break;
		case DSP_BASE ... DSP_BASE + 5: {
			dspreg_t *dregs;

			if (!cpu_has_dsp) {
				ret = -EIO;
				break;
			}

			dregs = __get_dsp_regs(child);
			dregs[addr - DSP_BASE] = data;
			break;
		}
		case DSP_CONTROL:
			if (!cpu_has_dsp) {
				ret = -EIO;
				break;
			}
			child->thread.dsp.dspcontrol = data;
			break;
		default:
			/* The rest are not allowed. */
			ret = -EIO;
			break;
		}
		break;
		}

	case PTRACE_SYSCALL: /* continue and stop at next (return from) syscall */
	case PTRACE_CONT: { /* restart after signal. */
		ret = -EIO;
		if (!valid_signal(data))
			break;
		if (request == PTRACE_SYSCALL) {
			set_tsk_thread_flag(child, TIF_SYSCALL_TRACE);
		}
		else {
			clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE);
		}
		child->exit_code = data;
		wake_up_process(child);
		ret = 0;
		break;
	}

	/*
	 * make the child exit.  Best I can do is send it a sigkill.
	 * perhaps it should be put in the status that it wants to
	 * exit.
	 */
	case PTRACE_KILL:
		ret = 0;
		if (child->exit_state == EXIT_ZOMBIE)	/* already dead */
			break;
		child->exit_code = SIGKILL;
		wake_up_process(child);
		break;

	case PTRACE_DETACH: /* detach a process that was attached. */
		ret = ptrace_detach(child, data);
		break;

	case PTRACE_GET_THREAD_AREA:
		ret = put_user(child->thread_info->tp_value,
				(unsigned long __user *) data);
		break;

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

out_tsk:
	put_task_struct(child);
out:
	unlock_kernel();
	return ret;
}

static inline int audit_arch(void)
{
	int arch = EM_MIPS;
#ifdef CONFIG_64BIT
	arch |=  __AUDIT_ARCH_64BIT;
#endif
#if defined(__LITTLE_ENDIAN)
	arch |=  __AUDIT_ARCH_LE;
#endif
	return arch;
}

/*
 * Notification of system call entry/exit
 * - triggered by current->work.syscall_trace
 */
asmlinkage void do_syscall_trace(struct pt_regs *regs, int entryexit)
{
	if (unlikely(current->audit_context) && entryexit)
		audit_syscall_exit(current, AUDITSC_RESULT(regs->regs[2]),
		                   regs->regs[2]);

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

	/* The 0x80 provides a way for the tracing parent to distinguish
	   between a syscall stop and SIGTRAP delivery */
	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;
	}
 out:
	if (unlikely(current->audit_context) && !entryexit)
		audit_syscall_entry(current, audit_arch(), regs->regs[2],
				    regs->regs[4], regs->regs[5],
				    regs->regs[6], regs->regs[7]);
}
Commit	Line	Data
1da177e4 LT	1	/*
	2	* This file is subject to the terms and conditions of the GNU General Public
	3	* License. See the file "COPYING" in the main directory of this archive
	4	* for more details.
	5	*
	6	* Copyright (C) 1992 Ross Biro
	7	* Copyright (C) Linus Torvalds
	8	* Copyright (C) 1994, 95, 96, 97, 98, 2000 Ralf Baechle
	9	* Copyright (C) 1996 David S. Miller
	10	* Kevin D. Kissell, kevink@mips.com and Carsten Langgaard, carstenl@mips.com
	11	* Copyright (C) 1999 MIPS Technologies, Inc.
	12	* Copyright (C) 2000 Ulf Carlsson
	13	*
	14	* At this time Linux/MIPS64 only supports syscall tracing, even for 32-bit
	15	* binaries.
	16	*/
	17	#include <linux/config.h>
	18	#include <linux/compiler.h>
	19	#include <linux/kernel.h>
	20	#include <linux/sched.h>
	21	#include <linux/mm.h>
	22	#include <linux/errno.h>
	23	#include <linux/ptrace.h>
	24	#include <linux/audit.h>
	25	#include <linux/smp.h>
	26	#include <linux/smp_lock.h>
	27	#include <linux/user.h>
	28	#include <linux/security.h>
7ed20e1a	29	#include <linux/signal.h>
1da177e4	30
f8280c8d	31	#include <asm/byteorder.h>
1da177e4	32	#include <asm/cpu.h>
e50c0a8f	33	#include <asm/dsp.h>
1da177e4 LT	34	#include <asm/fpu.h>
	35	#include <asm/mipsregs.h>
	36	#include <asm/pgtable.h>
	37	#include <asm/page.h>
	38	#include <asm/system.h>
	39	#include <asm/uaccess.h>
	40	#include <asm/bootinfo.h>
	41
	42	/*
	43	* Called by kernel/ptrace.c when detaching..
	44	*
	45	* Make sure single step bits etc are not set.
	46	*/
	47	void ptrace_disable(struct task_struct *child)
	48	{
	49	/* Nothing to do.. */
	50	}
	51
	52	asmlinkage int sys_ptrace(long request, long pid, long addr, long data)
	53	{
	54	struct task_struct *child;
	55	int ret;
	56
	57	#if 0
	58	printk("ptrace(r=%d,pid=%d,addr=%08lx,data=%08lx)\n",
	59	(int) request, (int) pid, (unsigned long) addr,
	60	(unsigned long) data);
	61	#endif
	62	lock_kernel();
	63	ret = -EPERM;
	64	if (request == PTRACE_TRACEME) {
	65	/* are we already being traced? */
	66	if (current->ptrace & PT_PTRACED)
	67	goto out;
	68	if ((ret = security_ptrace(current->parent, current)))
	69	goto out;
	70	/* set the ptrace bit in the process flags. */
	71	current->ptrace \|= PT_PTRACED;
	72	ret = 0;
	73	goto out;
	74	}
	75	ret = -ESRCH;
	76	read_lock(&tasklist_lock);
	77	child = find_task_by_pid(pid);
	78	if (child)
	79	get_task_struct(child);
	80	read_unlock(&tasklist_lock);
	81	if (!child)
	82	goto out;
	83
	84	ret = -EPERM;
	85	if (pid == 1) /* you may not mess with init */
	86	goto out_tsk;
	87
	88	if (request == PTRACE_ATTACH) {
	89	ret = ptrace_attach(child);
	90	goto out_tsk;
	91	}
	92
	93	ret = ptrace_check_attach(child, request == PTRACE_KILL);
	94	if (ret < 0)
	95	goto out_tsk;
	96
	97	switch (request) {
98	/* when I and D space are separate, these will need to be fixed. */
99	case PTRACE_PEEKTEXT: /* read word at location addr. */
100	case PTRACE_PEEKDATA: {
101	unsigned long tmp;
102	int copied;
103
104	copied = access_process_vm(child, addr, &tmp, sizeof(tmp), 0);
105	ret = -EIO;
106	if (copied != sizeof(tmp))
107	break;
fe00f943	108	ret = put_user(tmp,(unsigned long __user *) data);
1da177e4 LT	109	break;
	110	}
	111
	112	/* Read the word at location addr in the USER area. */
	113	case PTRACE_PEEKUSR: {
	114	struct pt_regs *regs;
	115	unsigned long tmp = 0;
	116
	117	regs = (struct pt_regs *) ((unsigned long) child->thread_info +
	118	THREAD_SIZE - 32 - sizeof(struct pt_regs));
	119	ret = 0; /* Default return value. */
	120
	121	switch (addr) {
	122	case 0 ... 31:
	123	tmp = regs->regs[addr];
	124	break;
	125	case FPR_BASE ... FPR_BASE + 31:
	126	if (tsk_used_math(child)) {
	127	fpureg_t *fregs = get_fpu_regs(child);
	128
875d43e7	129	#ifdef CONFIG_32BIT
1da177e4 LT	130	/*
	131	* The odd registers are actually the high
	132	* order bits of the values stored in the even
	133	* registers - unless we're using r2k_switch.S.
	134	*/
	135	if (addr & 1)
	136	tmp = (unsigned long) (fregs[((addr & ~1) - 32)] >> 32);
	137	else
	138	tmp = (unsigned long) (fregs[(addr - 32)] & 0xffffffff);
	139	#endif
875d43e7	140	#ifdef CONFIG_64BIT
1da177e4 LT	141	tmp = fregs[addr - FPR_BASE];
	142	#endif
	143	} else {
	144	tmp = -1; /* FP not yet used */
	145	}
	146	break;
	147	case PC:
	148	tmp = regs->cp0_epc;
	149	break;
	150	case CAUSE:
	151	tmp = regs->cp0_cause;
	152	break;
	153	case BADVADDR:
	154	tmp = regs->cp0_badvaddr;
	155	break;
	156	case MMHI:
	157	tmp = regs->hi;
	158	break;
	159	case MMLO:
	160	tmp = regs->lo;
	161	break;
	162	case FPC_CSR:
	163	if (cpu_has_fpu)
	164	tmp = child->thread.fpu.hard.fcr31;
	165	else
	166	tmp = child->thread.fpu.soft.fcr31;
	167	break;
	168	case FPC_EIR: { /* implementation / version register */
	169	unsigned int flags;
	170
	171	if (!cpu_has_fpu)
	172	break;
	173
	174	flags = read_c0_status();
	175	__enable_fpu();
	176	__asm__ __volatile__("cfc1\t%0,$0": "=r" (tmp));
	177	write_c0_status(flags);
	178	break;
	179	}
c134a5ec RB	180	case DSP_BASE ... DSP_BASE + 5: {
	181	dspreg_t *dregs;
	182
e50c0a8f RB	183	if (!cpu_has_dsp) {
	184	tmp = 0;
	185	ret = -EIO;
	186	goto out_tsk;
	187	}
	188	if (child->thread.dsp.used_dsp) {
c134a5ec	189	dregs = __get_dsp_regs(child);
e50c0a8f RB	190	tmp = (unsigned long) (dregs[addr - DSP_BASE]);
	191	} else {
	192	tmp = -1; /* DSP registers yet used */
	193	}
	194	break;
c134a5ec	195	}
e50c0a8f RB	196	case DSP_CONTROL:
	197	if (!cpu_has_dsp) {
	198	tmp = 0;
	199	ret = -EIO;
	200	goto out_tsk;
	201	}
	202	tmp = child->thread.dsp.dspcontrol;
	203	break;
1da177e4 LT	204	default:
	205	tmp = 0;
	206	ret = -EIO;
	207	goto out_tsk;
	208	}
fe00f943	209	ret = put_user(tmp, (unsigned long __user *) data);
1da177e4 LT	210	break;
	211	}
	212
	213	/* when I and D space are separate, this will have to be fixed. */
	214	case PTRACE_POKETEXT: /* write the word at location addr. */
	215	case PTRACE_POKEDATA:
	216	ret = 0;
	217	if (access_process_vm(child, addr, &data, sizeof(data), 1)
	218	== sizeof(data))
	219	break;
	220	ret = -EIO;
	221	break;
	222
	223	case PTRACE_POKEUSR: {
	224	struct pt_regs *regs;
	225	ret = 0;
	226	regs = (struct pt_regs *) ((unsigned long) child->thread_info +
	227	THREAD_SIZE - 32 - sizeof(struct pt_regs));
	228
	229	switch (addr) {
	230	case 0 ... 31:
	231	regs->regs[addr] = data;
	232	break;
	233	case FPR_BASE ... FPR_BASE + 31: {
	234	fpureg_t *fregs = get_fpu_regs(child);
	235
	236	if (!tsk_used_math(child)) {
	237	/* FP not yet used */
	238	memset(&child->thread.fpu.hard, ~0,
	239	sizeof(child->thread.fpu.hard));
	240	child->thread.fpu.hard.fcr31 = 0;
	241	}
875d43e7	242	#ifdef CONFIG_32BIT
1da177e4 LT	243	/*
	244	* The odd registers are actually the high order bits
	245	* of the values stored in the even registers - unless
	246	* we're using r2k_switch.S.
	247	*/
	248	if (addr & 1) {
	249	fregs[(addr & ~1) - FPR_BASE] &= 0xffffffff;
	250	fregs[(addr & ~1) - FPR_BASE] \|= ((unsigned long long) data) << 32;
	251	} else {
	252	fregs[addr - FPR_BASE] &= ~0xffffffffLL;
	253	fregs[addr - FPR_BASE] \|= data;
	254	}
	255	#endif
875d43e7	256	#ifdef CONFIG_64BIT
1da177e4 LT	257	fregs[addr - FPR_BASE] = data;
	258	#endif
	259	break;
	260	}
	261	case PC:
	262	regs->cp0_epc = data;
	263	break;
	264	case MMHI:
	265	regs->hi = data;
	266	break;
	267	case MMLO:
	268	regs->lo = data;
	269	break;
	270	case FPC_CSR:
	271	if (cpu_has_fpu)
	272	child->thread.fpu.hard.fcr31 = data;
	273	else
	274	child->thread.fpu.soft.fcr31 = data;
	275	break;
c134a5ec RB	276	case DSP_BASE ... DSP_BASE + 5: {
	277	dspreg_t *dregs;
	278
e50c0a8f RB	279	if (!cpu_has_dsp) {
	280	ret = -EIO;
	281	break;
	282	}
	283
c134a5ec	284	dregs = __get_dsp_regs(child);
e50c0a8f RB	285	dregs[addr - DSP_BASE] = data;
e50c0a8f RB	286	break;
c134a5ec	287	}
e50c0a8f RB	288	case DSP_CONTROL:
	289	if (!cpu_has_dsp) {
	290	ret = -EIO;
	291	break;
	292	}
	293	child->thread.dsp.dspcontrol = data;
	294	break;
1da177e4 LT	295	default:
	296	/* The rest are not allowed. */
	297	ret = -EIO;
	298	break;
	299	}
	300	break;
	301	}
	302
	303	case PTRACE_SYSCALL: /* continue and stop at next (return from) syscall */
	304	case PTRACE_CONT: { /* restart after signal. */
	305	ret = -EIO;
7ed20e1a	306	if (!valid_signal(data))
1da177e4 LT	307	break;
	308	if (request == PTRACE_SYSCALL) {
	309	set_tsk_thread_flag(child, TIF_SYSCALL_TRACE);
	310	}
	311	else {
	312	clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE);
	313	}
	314	child->exit_code = data;
	315	wake_up_process(child);
	316	ret = 0;
	317	break;
	318	}
	319
	320	/*
	321	* make the child exit. Best I can do is send it a sigkill.
	322	* perhaps it should be put in the status that it wants to
	323	* exit.
	324	*/
	325	case PTRACE_KILL:
	326	ret = 0;
	327	if (child->exit_state == EXIT_ZOMBIE) /* already dead */
	328	break;
	329	child->exit_code = SIGKILL;
	330	wake_up_process(child);
	331	break;
	332
	333	case PTRACE_DETACH: /* detach a process that was attached. */
	334	ret = ptrace_detach(child, data);
	335	break;
	336
3c37026d RB	337	case PTRACE_GET_THREAD_AREA:
	338	ret = put_user(child->thread_info->tp_value,
	339	(unsigned long __user *) data);
	340	break;
	341
1da177e4 LT	342	default:
	343	ret = ptrace_request(child, request, addr, data);
	344	break;
	345	}
	346
	347	out_tsk:
	348	put_task_struct(child);
	349	out:
	350	unlock_kernel();
	351	return ret;
	352	}
	353
67eb81e1	354	static inline int audit_arch(void)
2fd6f58b	355	{
f8280c8d	356	int arch = EM_MIPS;
875d43e7	357	#ifdef CONFIG_64BIT
f8280c8d RB	358	arch \|= __AUDIT_ARCH_64BIT;
	359	#endif
	360	#if defined(__LITTLE_ENDIAN)
	361	arch \|= __AUDIT_ARCH_LE;
	362	#endif
	363	return arch;
2fd6f58b	364	}
2fd6f58b	365
1da177e4 LT	366	/*
	367	* Notification of system call entry/exit
	368	* - triggered by current->work.syscall_trace
	369	*/
	370	asmlinkage void do_syscall_trace(struct pt_regs *regs, int entryexit)
	371	{
2fd6f58b	372	if (unlikely(current->audit_context) && entryexit)
f8280c8d RB	373	audit_syscall_exit(current, AUDITSC_RESULT(regs->regs[2]),
f8280c8d RB	374	regs->regs[2]);
1da177e4	375
1da177e4	376	if (!(current->ptrace & PT_PTRACED))
2fd6f58b	377	goto out;
f8280c8d RB	378	if (!test_thread_flag(TIF_SYSCALL_TRACE))
f8280c8d RB	379	goto out;
1da177e4 LT	380
	381	/* The 0x80 provides a way for the tracing parent to distinguish
	382	between a syscall stop and SIGTRAP delivery */
	383	ptrace_notify(SIGTRAP \| ((current->ptrace & PT_TRACESYSGOOD) ?
	384	0x80 : 0));
	385
	386	/*
	387	* this isn't the same as continuing with a signal, but it will do
	388	* for normal use. strace only continues with a signal if the
	389	* stopping signal is not SIGTRAP. -brl
	390	*/
	391	if (current->exit_code) {
	392	send_sig(current->exit_code, current, 1);
	393	current->exit_code = 0;
	394	}
2fd6f58b	395	out:
	396	if (unlikely(current->audit_context) && !entryexit)
	397	audit_syscall_entry(current, audit_arch(), regs->regs[2],
	398	regs->regs[4], regs->regs[5],
	399	regs->regs[6], regs->regs[7]);
1da177e4	400	}