[deliverable/linux.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 <linux/tracehook.h>
#include <linux/context_tracking.h>
#include <asm/traps.h>
#include <arch/chip.h>

#define CREATE_TRACE_POINTS
#include <trace/events/syscalls.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. */
		ret = copy_regset_to_user(child, &tile_user_regset_view,
					  REGSET_GPR, 0,
					  sizeof(struct pt_regs), datap);
		break;

	case PTRACE_SETREGS:  /* Set all registers in the child. */
		ret = copy_regset_from_user(child, &tile_user_regset_view,
					    REGSET_GPR, 0,
					    sizeof(struct pt_regs), datap);
		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

int do_syscall_trace_enter(struct pt_regs *regs)
{
	u32 work = ACCESS_ONCE(current_thread_info()->flags);

	if (secure_computing() == -1)
		return -1;

	if (work & _TIF_SYSCALL_TRACE) {
		if (tracehook_report_syscall_entry(regs))
			regs->regs[TREG_SYSCALL_NR] = -1;
	}

	if (work & _TIF_SYSCALL_TRACEPOINT)
		trace_sys_enter(regs, regs->regs[TREG_SYSCALL_NR]);

	return regs->regs[TREG_SYSCALL_NR];
}

void do_syscall_trace_exit(struct pt_regs *regs)
{
	long errno;

	/*
	 * The standard tile calling convention returns the value (or negative
	 * errno) in r0, and zero (or positive errno) in r1.
	 * It saves a couple of cycles on the hot path to do this work in
	 * registers only as we return, rather than updating the in-memory
	 * struct ptregs.
	 */
	errno = (long) regs->regs[0];
	if (errno < 0 && errno > -4096)
		regs->regs[1] = -errno;
	else
		regs->regs[1] = 0;

	if (test_thread_flag(TIF_SYSCALL_TRACE))
		tracehook_report_syscall_exit(regs, 0);

	if (test_thread_flag(TIF_SYSCALL_TRACEPOINT))
		trace_sys_exit(regs, regs->regs[0]);
}

void send_sigtrap(struct task_struct *tsk, struct pt_regs *regs)
{
	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);
}
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>
ef182724	24	#include <linux/tracehook.h>
49e4e156	25	#include <linux/context_tracking.h>
0707ad30	26	#include <asm/traps.h>
7be68284	27	#include <arch/chip.h>
867e359b	28
ef567f25 SM	29	#define CREATE_TRACE_POINTS
	30	#include <trace/events/syscalls.h>
	31
867e359b CM	32	void user_enable_single_step(struct task_struct *child)
	33	{
	34	set_tsk_thread_flag(child, TIF_SINGLESTEP);
	35	}
	36
	37	void user_disable_single_step(struct task_struct *child)
	38	{
	39	clear_tsk_thread_flag(child, TIF_SINGLESTEP);
	40	}
	41
867e359b CM	42	/*
	43	* Called by kernel/ptrace.c when detaching..
	44	*/
	45	void ptrace_disable(struct task_struct *child)
	46	{
	47	clear_tsk_thread_flag(child, TIF_SINGLESTEP);
	48
	49	/*
	50	* These two are currently unused, but will be set by arch_ptrace()
	51	* and used in the syscall assembly when we do support them.
	52	*/
	53	clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE);
	54	}
	55
cb67e161 CM	56	/*
	57	* Get registers from task and ready the result for userspace.
	58	* Note that we localize the API issues to getregs() and putregs() at
	59	* some cost in performance, e.g. we need a full pt_regs copy for
	60	* PEEKUSR, and two copies for POKEUSR. But in general we expect
	61	* GETREGS/PUTREGS to be the API of choice anyway.
	62	*/
	63	static char getregs(struct task_struct child, struct pt_regs *uregs)
	64	{
	65	uregs = task_pt_regs(child);
	66
	67	/* Set up flags ABI bits. */
	68	uregs->flags = 0;
	69	#ifdef CONFIG_COMPAT
	70	if (task_thread_info(child)->status & TS_COMPAT)
	71	uregs->flags \|= PT_FLAGS_COMPAT;
	72	#endif
	73
	74	return (char *)uregs;
	75	}
	76
	77	/* Put registers back to task. */
	78	static void putregs(struct task_struct child, struct pt_regs uregs)
	79	{
	80	struct pt_regs *regs = task_pt_regs(child);
	81
	82	/* Don't allow overwriting the kernel-internal flags word. */
	83	uregs->flags = regs->flags;
	84
	85	/* Only allow setting the ICS bit in the ex1 word. */
	86	uregs->ex1 = PL_ICS_EX1(USER_PL, EX1_ICS(uregs->ex1));
	87
	88	regs = uregs;
	89	}
	90
7be68284 SM	91	enum tile_regset {
	92	REGSET_GPR,
	93	};
	94
	95	static int tile_gpr_get(struct task_struct *target,
	96	const struct user_regset *regset,
	97	unsigned int pos, unsigned int count,
	98	void kbuf, void __user ubuf)
	99	{
	100	struct pt_regs regs;
	101
	102	getregs(target, &regs);
	103
	104	return user_regset_copyout(&pos, &count, &kbuf, &ubuf, &regs, 0,
	105	sizeof(regs));
	106	}
	107
	108	static int tile_gpr_set(struct task_struct *target,
	109	const struct user_regset *regset,
	110	unsigned int pos, unsigned int count,
	111	const void kbuf, const void __user ubuf)
	112	{
	113	int ret;
	114	struct pt_regs regs;
	115
	116	ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, &regs, 0,
	117	sizeof(regs));
	118	if (ret)
	119	return ret;
	120
	121	putregs(target, &regs);
	122
	123	return 0;
	124	}
	125
	126	static const struct user_regset tile_user_regset[] = {
	127	[REGSET_GPR] = {
	128	.core_note_type = NT_PRSTATUS,
	129	.n = ELF_NGREG,
	130	.size = sizeof(elf_greg_t),
	131	.align = sizeof(elf_greg_t),
	132	.get = tile_gpr_get,
	133	.set = tile_gpr_set,
	134	},
	135	};
	136
	137	static const struct user_regset_view tile_user_regset_view = {
	138	.name = CHIP_ARCH_NAME,
	139	.e_machine = ELF_ARCH,
	140	.ei_osabi = ELF_OSABI,
	141	.regsets = tile_user_regset,
	142	.n = ARRAY_SIZE(tile_user_regset),
	143	};
	144
	145	const struct user_regset_view task_user_regset_view(struct task_struct task)
	146	{
	147	return &tile_user_regset_view;
	148	}
	149
9b05a69e NK	150	long arch_ptrace(struct task_struct *child, long request,
9b05a69e NK	151	unsigned long addr, unsigned long data)
867e359b	152	{
ce7f2a39	153	unsigned long __user datap = (long __user __force )data;
867e359b	154	unsigned long tmp;
867e359b	155	long ret = -EIO;
ce7f2a39	156	char *childreg;
1deb9c5d	157	struct pt_regs copyregs;
867e359b CM	158
	159	switch (request) {
	160
	161	case PTRACE_PEEKUSR: /* Read register from pt_regs. */
8c0acac3	162	if (addr >= PTREGS_SIZE)
867e359b	163	break;
cb67e161	164	childreg = getregs(child, &copyregs) + addr;
ce7f2a39 CM	165	#ifdef CONFIG_COMPAT
	166	if (is_compat_task()) {
	167	if (addr & (sizeof(compat_long_t)-1))
	168	break;
	169	ret = put_user((compat_long_t )childreg,
	170	(compat_long_t __user *)datap);
	171	} else
	172	#endif
	173	{
	174	if (addr & (sizeof(long)-1))
	175	break;
	176	ret = put_user((long )childreg, datap);
	177	}
867e359b CM	178	break;
	179
	180	case PTRACE_POKEUSR: /* Write register in pt_regs. */
8c0acac3	181	if (addr >= PTREGS_SIZE)
867e359b	182	break;
cb67e161	183	childreg = getregs(child, &copyregs) + addr;
ce7f2a39 CM	184	#ifdef CONFIG_COMPAT
	185	if (is_compat_task()) {
	186	if (addr & (sizeof(compat_long_t)-1))
	187	break;
	188	(compat_long_t )childreg = data;
	189	} else
	190	#endif
	191	{
	192	if (addr & (sizeof(long)-1))
	193	break;
	194	(long )childreg = data;
	195	}
cb67e161	196	putregs(child, &copyregs);
bcd97c3f	197	ret = 0;
867e359b CM	198	break;
	199
	200	case PTRACE_GETREGS: /* Get all registers from the child. */
9af62547 SM	201	ret = copy_regset_to_user(child, &tile_user_regset_view,
	202	REGSET_GPR, 0,
	203	sizeof(struct pt_regs), datap);
867e359b CM	204	break;
	205
	206	case PTRACE_SETREGS: /* Set all registers in the child. */
9af62547 SM	207	ret = copy_regset_from_user(child, &tile_user_regset_view,
	208	REGSET_GPR, 0,
	209	sizeof(struct pt_regs), datap);
867e359b CM	210	break;
	211
	212	case PTRACE_GETFPREGS: /* Get the child FPU state. */
	213	case PTRACE_SETFPREGS: /* Set the child FPU state. */
	214	break;
	215
	216	case PTRACE_SETOPTIONS:
	217	/* Support TILE-specific ptrace options. */
395e095e	218	BUILD_BUG_ON(PTRACE_O_MASK_TILE & PTRACE_O_MASK);
867e359b CM	219	tmp = data & PTRACE_O_MASK_TILE;
	220	data &= ~PTRACE_O_MASK_TILE;
	221	ret = ptrace_request(child, request, addr, data);
395e095e CM	222	if (ret == 0) {
	223	unsigned int flags = child->ptrace;
	224	flags &= ~(PTRACE_O_MASK_TILE << PT_OPT_FLAG_SHIFT);
	225	flags \|= (tmp << PT_OPT_FLAG_SHIFT);
	226	child->ptrace = flags;
	227	}
867e359b CM	228	break;
	229
	230	default:
	231	#ifdef CONFIG_COMPAT
	232	if (task_thread_info(current)->status & TS_COMPAT) {
	233	ret = compat_ptrace_request(child, request,
	234	addr, data);
	235	break;
	236	}
	237	#endif
	238	ret = ptrace_request(child, request, addr, data);
	239	break;
	240	}
	241
	242	return ret;
	243	}
	244
	245	#ifdef CONFIG_COMPAT
	246	/* Not used; we handle compat issues in arch_ptrace() directly. */
	247	long compat_arch_ptrace(struct task_struct *child, compat_long_t request,
	248	compat_ulong_t addr, compat_ulong_t data)
	249	{
	250	BUG();
	251	}
	252	#endif
	253
ef182724	254	int do_syscall_trace_enter(struct pt_regs *regs)
867e359b	255	{
49e4e156 CM	256	u32 work = ACCESS_ONCE(current_thread_info()->flags);
49e4e156 CM	257
a0ddef81 CM	258	if (secure_computing() == -1)
	259	return -1;
	260
49e4e156	261	if (work & _TIF_SYSCALL_TRACE) {
ef567f25 SM	262	if (tracehook_report_syscall_entry(regs))
ef567f25 SM	263	regs->regs[TREG_SYSCALL_NR] = -1;
ef182724	264	}
867e359b	265
49e4e156	266	if (work & _TIF_SYSCALL_TRACEPOINT)
ef567f25 SM	267	trace_sys_enter(regs, regs->regs[TREG_SYSCALL_NR]);
ef567f25 SM	268
ef182724 SM	269	return regs->regs[TREG_SYSCALL_NR];
ef182724 SM	270	}
867e359b	271
ef182724 SM	272	void do_syscall_trace_exit(struct pt_regs *regs)
ef182724 SM	273	{
9b5bbf72 CM	274	long errno;
	275
	276	/*
	277	* The standard tile calling convention returns the value (or negative
	278	* errno) in r0, and zero (or positive errno) in r1.
	279	* It saves a couple of cycles on the hot path to do this work in
	280	* registers only as we return, rather than updating the in-memory
	281	* struct ptregs.
	282	*/
	283	errno = (long) regs->regs[0];
	284	if (errno < 0 && errno > -4096)
	285	regs->regs[1] = -errno;
	286	else
	287	regs->regs[1] = 0;
	288
ef567f25 SM	289	if (test_thread_flag(TIF_SYSCALL_TRACE))
	290	tracehook_report_syscall_exit(regs, 0);
	291
	292	if (test_thread_flag(TIF_SYSCALL_TRACEPOINT))
9fc1894c	293	trace_sys_exit(regs, regs->regs[0]);
867e359b CM	294	}
867e359b CM	295
2f9ac29e	296	void send_sigtrap(struct task_struct tsk, struct pt_regs regs)
867e359b CM	297	{
	298	struct siginfo info;
	299
	300	memset(&info, 0, sizeof(info));
	301	info.si_signo = SIGTRAP;
	302	info.si_code = TRAP_BRKPT;
	303	info.si_addr = (void __user *) regs->pc;
	304
	305	/* Send us the fakey SIGTRAP */
	306	force_sig_info(SIGTRAP, &info, tsk);
	307	}
	308
	309	/* Handle synthetic interrupt delivered only by the simulator. */
	310	void __kprobes do_breakpoint(struct pt_regs* regs, int fault_num)
	311	{
2f9ac29e	312	send_sigtrap(current, regs);
867e359b	313	}