[GitHub/mt8127/android_kernel_alcatel_ttab.git] / arch / tile / kernel / ptrace.c

/*
 * Copyright 2010 Tilera Corporation. All Rights Reserved.
 *
 *   This program is free software; you can redistribute it and/or
 *   modify it under the terms of the GNU General Public License
 *   as published by the Free Software Foundation, version 2.
 *
 *   This program is distributed in the hope that it will be useful, but
 *   WITHOUT ANY WARRANTY; without even the implied warranty of
 *   MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or
 *   NON INFRINGEMENT.  See the GNU General Public License for
 *   more details.
 *
 * Copied from i386: Ross Biro 1/23/92
 */

#include <linux/kernel.h>
#include <linux/ptrace.h>
#include <linux/kprobes.h>
#include <linux/compat.h>
#include <linux/uaccess.h>
#include <linux/regset.h>
#include <linux/elf.h>
#include <asm/traps.h>
#include <arch/chip.h>

void user_enable_single_step(struct task_struct *child)
{
	set_tsk_thread_flag(child, TIF_SINGLESTEP);
}

void user_disable_single_step(struct task_struct *child)
{
	clear_tsk_thread_flag(child, TIF_SINGLESTEP);
}

/*
 * Called by kernel/ptrace.c when detaching..
 */
void ptrace_disable(struct task_struct *child)
{
	clear_tsk_thread_flag(child, TIF_SINGLESTEP);

	/*
	 * These two are currently unused, but will be set by arch_ptrace()
	 * and used in the syscall assembly when we do support them.
	 */
	clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE);
}

/*
 * Get registers from task and ready the result for userspace.
 * Note that we localize the API issues to getregs() and putregs() at
 * some cost in performance, e.g. we need a full pt_regs copy for
 * PEEKUSR, and two copies for POKEUSR.  But in general we expect
 * GETREGS/PUTREGS to be the API of choice anyway.
 */
static char *getregs(struct task_struct *child, struct pt_regs *uregs)
{
	*uregs = *task_pt_regs(child);

	/* Set up flags ABI bits. */
	uregs->flags = 0;
#ifdef CONFIG_COMPAT
	if (task_thread_info(child)->status & TS_COMPAT)
		uregs->flags |= PT_FLAGS_COMPAT;
#endif

	return (char *)uregs;
}

/* Put registers back to task. */
static void putregs(struct task_struct *child, struct pt_regs *uregs)
{
	struct pt_regs *regs = task_pt_regs(child);

	/* Don't allow overwriting the kernel-internal flags word. */
	uregs->flags = regs->flags;

	/* Only allow setting the ICS bit in the ex1 word. */
	uregs->ex1 = PL_ICS_EX1(USER_PL, EX1_ICS(uregs->ex1));

	*regs = *uregs;
}

enum tile_regset {
	REGSET_GPR,
};

static int tile_gpr_get(struct task_struct *target,
			  const struct user_regset *regset,
			  unsigned int pos, unsigned int count,
			  void *kbuf, void __user *ubuf)
{
	struct pt_regs regs;

	getregs(target, &regs);

	return user_regset_copyout(&pos, &count, &kbuf, &ubuf, &regs, 0,
				   sizeof(regs));
}

static int tile_gpr_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;
	struct pt_regs regs;

	ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, &regs, 0,
				 sizeof(regs));
	if (ret)
		return ret;

	putregs(target, &regs);

	return 0;
}

static const struct user_regset tile_user_regset[] = {
	[REGSET_GPR] = {
		.core_note_type = NT_PRSTATUS,
		.n = ELF_NGREG,
		.size = sizeof(elf_greg_t),
		.align = sizeof(elf_greg_t),
		.get = tile_gpr_get,
		.set = tile_gpr_set,
	},
};

static const struct user_regset_view tile_user_regset_view = {
	.name = CHIP_ARCH_NAME,
	.e_machine = ELF_ARCH,
	.ei_osabi = ELF_OSABI,
	.regsets = tile_user_regset,
	.n = ARRAY_SIZE(tile_user_regset),
};

const struct user_regset_view *task_user_regset_view(struct task_struct *task)
{
	return &tile_user_regset_view;
}

long arch_ptrace(struct task_struct *child, long request,
		 unsigned long addr, unsigned long data)
{
	unsigned long __user *datap = (long __user __force *)data;
	unsigned long tmp;
	long ret = -EIO;
	char *childreg;
	struct pt_regs copyregs;

	switch (request) {

	case PTRACE_PEEKUSR:  /* Read register from pt_regs. */
		if (addr >= PTREGS_SIZE)
			break;
		childreg = getregs(child, &copyregs) + addr;
#ifdef CONFIG_COMPAT
		if (is_compat_task()) {
			if (addr & (sizeof(compat_long_t)-1))
				break;
			ret = put_user(*(compat_long_t *)childreg,
				       (compat_long_t __user *)datap);
		} else
#endif
		{
			if (addr & (sizeof(long)-1))
				break;
			ret = put_user(*(long *)childreg, datap);
		}
		break;

	case PTRACE_POKEUSR:  /* Write register in pt_regs. */
		if (addr >= PTREGS_SIZE)
			break;
		childreg = getregs(child, &copyregs) + addr;
#ifdef CONFIG_COMPAT
		if (is_compat_task()) {
			if (addr & (sizeof(compat_long_t)-1))
				break;
			*(compat_long_t *)childreg = data;
		} else
#endif
		{
			if (addr & (sizeof(long)-1))
				break;
			*(long *)childreg = data;
		}
		putregs(child, &copyregs);
		ret = 0;
		break;

	case PTRACE_GETREGS:  /* Get all registers from the child. */
		if (copy_to_user(datap, getregs(child, &copyregs),
				 sizeof(struct pt_regs)) == 0) {
			ret = 0;
		}
		break;

	case PTRACE_SETREGS:  /* Set all registers in the child. */
		if (copy_from_user(&copyregs, datap,
				   sizeof(struct pt_regs)) == 0) {
			putregs(child, &copyregs);
			ret = 0;
		}
		break;

	case PTRACE_GETFPREGS:  /* Get the child FPU state. */
	case PTRACE_SETFPREGS:  /* Set the child FPU state. */
		break;

	case PTRACE_SETOPTIONS:
		/* Support TILE-specific ptrace options. */
		BUILD_BUG_ON(PTRACE_O_MASK_TILE & PTRACE_O_MASK);
		tmp = data & PTRACE_O_MASK_TILE;
		data &= ~PTRACE_O_MASK_TILE;
		ret = ptrace_request(child, request, addr, data);
		if (ret == 0) {
			unsigned int flags = child->ptrace;
			flags &= ~(PTRACE_O_MASK_TILE << PT_OPT_FLAG_SHIFT);
			flags |= (tmp << PT_OPT_FLAG_SHIFT);
			child->ptrace = flags;
		}
		break;

	default:
#ifdef CONFIG_COMPAT
		if (task_thread_info(current)->status & TS_COMPAT) {
			ret = compat_ptrace_request(child, request,
						    addr, data);
			break;
		}
#endif
		ret = ptrace_request(child, request, addr, data);
		break;
	}

	return ret;
}

#ifdef CONFIG_COMPAT
/* Not used; we handle compat issues in arch_ptrace() directly. */
long compat_arch_ptrace(struct task_struct *child, compat_long_t request,
			       compat_ulong_t addr, compat_ulong_t data)
{
	BUG();
}
#endif

void do_syscall_trace(void)
{
	if (!test_thread_flag(TIF_SYSCALL_TRACE))
		return;

	if (!(current->ptrace & PT_PTRACED))
		return;

	/*
	 * 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;
	}
}

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

	memset(&info, 0, sizeof(info));
	info.si_signo = SIGTRAP;
	info.si_code  = TRAP_BRKPT;
	info.si_addr  = (void __user *) regs->pc;

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

/* Handle synthetic interrupt delivered only by the simulator. */
void __kprobes do_breakpoint(struct pt_regs* regs, int fault_num)
{
	send_sigtrap(current, regs, fault_num);
}
Commit	Line	Data
867e359b CM	1	/*
	2	* Copyright 2010 Tilera Corporation. All Rights Reserved.
	3	*
	4	* This program is free software; you can redistribute it and/or
	5	* modify it under the terms of the GNU General Public License
	6	* as published by the Free Software Foundation, version 2.
	7	*
	8	* This program is distributed in the hope that it will be useful, but
	9	* WITHOUT ANY WARRANTY; without even the implied warranty of
	10	* MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or
	11	* NON INFRINGEMENT. See the GNU General Public License for
	12	* more details.
	13	*
	14	* Copied from i386: Ross Biro 1/23/92
	15	*/
	16
	17	#include <linux/kernel.h>
	18	#include <linux/ptrace.h>
	19	#include <linux/kprobes.h>
	20	#include <linux/compat.h>
	21	#include <linux/uaccess.h>
7be68284 SM	22	#include <linux/regset.h>
7be68284 SM	23	#include <linux/elf.h>
0707ad30	24	#include <asm/traps.h>
7be68284	25	#include <arch/chip.h>
867e359b CM	26
	27	void user_enable_single_step(struct task_struct *child)
	28	{
	29	set_tsk_thread_flag(child, TIF_SINGLESTEP);
	30	}
	31
	32	void user_disable_single_step(struct task_struct *child)
	33	{
	34	clear_tsk_thread_flag(child, TIF_SINGLESTEP);
	35	}
	36
867e359b CM	37	/*
	38	* Called by kernel/ptrace.c when detaching..
	39	*/
	40	void ptrace_disable(struct task_struct *child)
	41	{
	42	clear_tsk_thread_flag(child, TIF_SINGLESTEP);
	43
	44	/*
	45	* These two are currently unused, but will be set by arch_ptrace()
	46	* and used in the syscall assembly when we do support them.
	47	*/
	48	clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE);
	49	}
	50
cb67e161 CM	51	/*
	52	* Get registers from task and ready the result for userspace.
	53	* Note that we localize the API issues to getregs() and putregs() at
	54	* some cost in performance, e.g. we need a full pt_regs copy for
	55	* PEEKUSR, and two copies for POKEUSR. But in general we expect
	56	* GETREGS/PUTREGS to be the API of choice anyway.
	57	*/
	58	static char getregs(struct task_struct child, struct pt_regs *uregs)
	59	{
	60	uregs = task_pt_regs(child);
	61
	62	/* Set up flags ABI bits. */
	63	uregs->flags = 0;
	64	#ifdef CONFIG_COMPAT
	65	if (task_thread_info(child)->status & TS_COMPAT)
	66	uregs->flags \|= PT_FLAGS_COMPAT;
	67	#endif
	68
	69	return (char *)uregs;
	70	}
	71
	72	/* Put registers back to task. */
	73	static void putregs(struct task_struct child, struct pt_regs uregs)
	74	{
	75	struct pt_regs *regs = task_pt_regs(child);
	76
	77	/* Don't allow overwriting the kernel-internal flags word. */
	78	uregs->flags = regs->flags;
	79
	80	/* Only allow setting the ICS bit in the ex1 word. */
	81	uregs->ex1 = PL_ICS_EX1(USER_PL, EX1_ICS(uregs->ex1));
	82
	83	regs = uregs;
	84	}
	85
7be68284 SM	86	enum tile_regset {
	87	REGSET_GPR,
	88	};
	89
	90	static int tile_gpr_get(struct task_struct *target,
	91	const struct user_regset *regset,
	92	unsigned int pos, unsigned int count,
	93	void kbuf, void __user ubuf)
	94	{
	95	struct pt_regs regs;
	96
	97	getregs(target, &regs);
	98
	99	return user_regset_copyout(&pos, &count, &kbuf, &ubuf, &regs, 0,
	100	sizeof(regs));
	101	}
	102
	103	static int tile_gpr_set(struct task_struct *target,
	104	const struct user_regset *regset,
	105	unsigned int pos, unsigned int count,
	106	const void kbuf, const void __user ubuf)
	107	{
	108	int ret;
	109	struct pt_regs regs;
	110
	111	ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, &regs, 0,
	112	sizeof(regs));
	113	if (ret)
	114	return ret;
	115
	116	putregs(target, &regs);
	117
	118	return 0;
	119	}
	120
	121	static const struct user_regset tile_user_regset[] = {
	122	[REGSET_GPR] = {
	123	.core_note_type = NT_PRSTATUS,
	124	.n = ELF_NGREG,
	125	.size = sizeof(elf_greg_t),
	126	.align = sizeof(elf_greg_t),
	127	.get = tile_gpr_get,
	128	.set = tile_gpr_set,
	129	},
	130	};
	131
	132	static const struct user_regset_view tile_user_regset_view = {
	133	.name = CHIP_ARCH_NAME,
	134	.e_machine = ELF_ARCH,
	135	.ei_osabi = ELF_OSABI,
	136	.regsets = tile_user_regset,
	137	.n = ARRAY_SIZE(tile_user_regset),
	138	};
	139
	140	const struct user_regset_view task_user_regset_view(struct task_struct task)
	141	{
	142	return &tile_user_regset_view;
	143	}
	144
9b05a69e NK	145	long arch_ptrace(struct task_struct *child, long request,
9b05a69e NK	146	unsigned long addr, unsigned long data)
867e359b	147	{
ce7f2a39	148	unsigned long __user datap = (long __user __force )data;
867e359b	149	unsigned long tmp;
867e359b	150	long ret = -EIO;
ce7f2a39	151	char *childreg;
1deb9c5d	152	struct pt_regs copyregs;
867e359b CM	153
	154	switch (request) {
	155
	156	case PTRACE_PEEKUSR: /* Read register from pt_regs. */
8c0acac3	157	if (addr >= PTREGS_SIZE)
867e359b	158	break;
cb67e161	159	childreg = getregs(child, &copyregs) + addr;
ce7f2a39 CM	160	#ifdef CONFIG_COMPAT
	161	if (is_compat_task()) {
	162	if (addr & (sizeof(compat_long_t)-1))
	163	break;
	164	ret = put_user((compat_long_t )childreg,
	165	(compat_long_t __user *)datap);
	166	} else
	167	#endif
	168	{
	169	if (addr & (sizeof(long)-1))
	170	break;
	171	ret = put_user((long )childreg, datap);
	172	}
867e359b CM	173	break;
	174
	175	case PTRACE_POKEUSR: /* Write register in pt_regs. */
8c0acac3	176	if (addr >= PTREGS_SIZE)
867e359b	177	break;
cb67e161	178	childreg = getregs(child, &copyregs) + addr;
ce7f2a39 CM	179	#ifdef CONFIG_COMPAT
	180	if (is_compat_task()) {
	181	if (addr & (sizeof(compat_long_t)-1))
	182	break;
	183	(compat_long_t )childreg = data;
	184	} else
	185	#endif
	186	{
	187	if (addr & (sizeof(long)-1))
	188	break;
	189	(long )childreg = data;
	190	}
cb67e161	191	putregs(child, &copyregs);
bcd97c3f	192	ret = 0;
867e359b CM	193	break;
	194
	195	case PTRACE_GETREGS: /* Get all registers from the child. */
cb67e161	196	if (copy_to_user(datap, getregs(child, &copyregs),
1deb9c5d CM	197	sizeof(struct pt_regs)) == 0) {
1deb9c5d CM	198	ret = 0;
867e359b CM	199	}
	200	break;
	201
	202	case PTRACE_SETREGS: /* Set all registers in the child. */
1deb9c5d CM	203	if (copy_from_user(&copyregs, datap,
1deb9c5d CM	204	sizeof(struct pt_regs)) == 0) {
cb67e161	205	putregs(child, &copyregs);
1deb9c5d	206	ret = 0;
867e359b CM	207	}
	208	break;
	209
	210	case PTRACE_GETFPREGS: /* Get the child FPU state. */
	211	case PTRACE_SETFPREGS: /* Set the child FPU state. */
	212	break;
	213
	214	case PTRACE_SETOPTIONS:
	215	/* Support TILE-specific ptrace options. */
395e095e	216	BUILD_BUG_ON(PTRACE_O_MASK_TILE & PTRACE_O_MASK);
867e359b CM	217	tmp = data & PTRACE_O_MASK_TILE;
	218	data &= ~PTRACE_O_MASK_TILE;
	219	ret = ptrace_request(child, request, addr, data);
395e095e CM	220	if (ret == 0) {
	221	unsigned int flags = child->ptrace;
	222	flags &= ~(PTRACE_O_MASK_TILE << PT_OPT_FLAG_SHIFT);
	223	flags \|= (tmp << PT_OPT_FLAG_SHIFT);
	224	child->ptrace = flags;
	225	}
867e359b CM	226	break;
	227
	228	default:
	229	#ifdef CONFIG_COMPAT
	230	if (task_thread_info(current)->status & TS_COMPAT) {
	231	ret = compat_ptrace_request(child, request,
	232	addr, data);
	233	break;
	234	}
	235	#endif
	236	ret = ptrace_request(child, request, addr, data);
	237	break;
	238	}
	239
	240	return ret;
	241	}
	242
	243	#ifdef CONFIG_COMPAT
	244	/* Not used; we handle compat issues in arch_ptrace() directly. */
	245	long compat_arch_ptrace(struct task_struct *child, compat_long_t request,
	246	compat_ulong_t addr, compat_ulong_t data)
	247	{
	248	BUG();
	249	}
	250	#endif
	251
	252	void do_syscall_trace(void)
	253	{
	254	if (!test_thread_flag(TIF_SYSCALL_TRACE))
	255	return;
	256
	257	if (!(current->ptrace & PT_PTRACED))
	258	return;
	259
	260	/*
	261	* The 0x80 provides a way for the tracing parent to distinguish
	262	* between a syscall stop and SIGTRAP delivery
	263	*/
	264	ptrace_notify(SIGTRAP\|((current->ptrace & PT_TRACESYSGOOD) ? 0x80 : 0));
	265
	266	/*
	267	* this isn't the same as continuing with a signal, but it will do
	268	* for normal use. strace only continues with a signal if the
	269	* stopping signal is not SIGTRAP. -brl
	270	*/
	271	if (current->exit_code) {
	272	send_sig(current->exit_code, current, 1);
	273	current->exit_code = 0;
	274	}
	275	}
	276
	277	void send_sigtrap(struct task_struct tsk, struct pt_regs regs, int error_code)
	278	{
	279	struct siginfo info;
	280
	281	memset(&info, 0, sizeof(info));
	282	info.si_signo = SIGTRAP;
	283	info.si_code = TRAP_BRKPT;
	284	info.si_addr = (void __user *) regs->pc;
	285
	286	/* Send us the fakey SIGTRAP */
	287	force_sig_info(SIGTRAP, &info, tsk);
	288	}
	289
290	/* Handle synthetic interrupt delivered only by the simulator. */
291	void __kprobes do_breakpoint(struct pt_regs* regs, int fault_num)
292	{
293	send_sigtrap(current, regs, fault_num);
294	}