/*	$NetBSD: linux_ptrace.c,v 1.10 2003/01/18 08:02:50 thorpej Exp $ */

/*-
 * Copyright (c) 1999, 2001 The NetBSD Foundation, Inc.
 * All rights reserved.
 *
 * This code is derived from software contributed to The NetBSD Foundation
 * by Matthias Scheler and Emmanuel Dreyfus.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *	This product includes software developed by the NetBSD
 *	Foundation, Inc. and its contributors.
 * 4. Neither the name of The NetBSD Foundation nor the names of its
 *    contributors may be used to endorse or promote products derived
 *    from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 * POSSIBILITY OF SUCH DAMAGE.
 */

#include <sys/cdefs.h>
__KERNEL_RCSID(0, "$NetBSD: linux_ptrace.c,v 1.10 2003/01/18 08:02:50 thorpej Exp $");

#include <sys/param.h>
#include <sys/malloc.h>
#include <sys/mount.h>
#include <sys/proc.h>
#include <sys/ptrace.h>
#include <sys/systm.h>
#include <sys/sa.h>
#include <sys/syscallargs.h>
#include <uvm/uvm_extern.h>

#include <machine/reg.h>

#include <compat/linux/common/linux_types.h>
#include <compat/linux/common/linux_ptrace.h>
#include <compat/linux/common/linux_signal.h>

#include <compat/linux/common/linux_util.h>
#include <compat/linux/common/linux_machdep.h>
#include <compat/linux/common/linux_emuldata.h>
#include <compat/linux/common/linux_exec.h>	/* for emul_linux */

#include <compat/linux/linux_syscallargs.h>

#include <lib/libkern/libkern.h>	/* for offsetof() */

/* 
 * From Linux's include/asm-ppc/ptrace.h.  
 * structure used for storing reg context:  defined in linux_machdep.h 
 * structure used for storing floating point context:
 * Linux just uses a double fpr[32], no struct 
 */
 
/* 
 * user struct for linux process - this is used for Linux ptrace emulation 
 * most of it is junk only used by gdb 
 * 
 * From Linux's include/asm-ppc/user.h 
 * 
 * XXX u_ar0 was a struct reg in Linux/powerpc 
 * Can't find out what a struct regs is for Linux/powerpc, 
 * so we use a struct pt_regs instead. don't know if this is right.
 */

struct linux_user {
	struct linux_pt_regs regs;		
#define lusr_startgdb regs
	size_t u_tsize;	 
	size_t u_dsize;	 
	size_t u_ssize;	 
	unsigned long start_code;
	unsigned long start_data;
	unsigned long start_stack;
	long int signal;	  
	struct linux_pt_regs *u_ar0;		/* help gdb find registers */
	unsigned long magic;		  
	char u_comm[32];	 
#define lu_comm_end u_comm[31]
};

#define LUSR_OFF(member) offsetof(struct linux_user, member)
#define LUSR_REG_OFF(member) offsetof(struct linux_pt_regs, member)
#define ISSET(t, f) ((t) & (f))

int
linux_sys_ptrace_arch(l, v, retval)	/* XXX Check me! (From NetBSD/i386) */
	struct lwp *l;
	void *v;
	register_t *retval;
{
	struct linux_sys_ptrace_args /* {
		syscallarg(int) request;
		syscallarg(int) pid;
		syscallarg(int) addr;
		syscallarg(int) data;
	} */ *uap = v;
	int request, error;
	struct proc *p = l->l_proc;
	struct proc *t;				/* target process */
	struct lwp *lt;
	struct reg *regs = NULL;
	struct fpreg *fpregs = NULL;
	struct linux_pt_regs *linux_regs = NULL;
	double *linux_fpreg = NULL;  /* it's an array, not a struct */
	int addr;
	int i;

	switch (request = SCARG(uap, request)) {
		case LINUX_PTRACE_PEEKUSR:
		case LINUX_PTRACE_POKEUSR:
		case LINUX_PTRACE_GETREGS:
		case LINUX_PTRACE_SETREGS:
		case LINUX_PTRACE_GETFPREGS:
		case LINUX_PTRACE_SETFPREGS:
			break;
		default:
			return EIO;
	}

	/* Find the process we're supposed to be operating on. */
	if ((t = pfind(SCARG(uap, pid))) == NULL)
		return ESRCH;

	/*
	 * You can't do what you want to the process if:
	 *	(1) It's not being traced at all,
	 */
	if (!ISSET(t->p_flag, P_TRACED))
		return EPERM;

	/*
	 *	(2) it's being traced by procfs (which has
	 *		 different signal delivery semantics),
	 */
	if (ISSET(t->p_flag, P_FSTRACE))
		return EBUSY;

	/*
	 *	(3) it's not being traced by _you_, or
	 */
	if (t->p_pptr != p)
		return EBUSY;

	/*
	 *	(4) it's not currently stopped.
	 */
	if (t->p_stat != SSTOP || !ISSET(t->p_flag, P_WAITED))
		return EBUSY;

	lt = LIST_FIRST(&t->p_lwps);
	*retval = 0;

	switch (request) {
	case  LINUX_PTRACE_GETREGS:
		MALLOC(regs, struct reg*, sizeof(struct reg), M_TEMP, M_WAITOK);
		MALLOC(linux_regs, struct linux_pt_regs*, sizeof(*linux_regs),
		    M_TEMP, M_WAITOK);

		error = process_read_regs(lt, regs);
		if (error != 0)
			goto out;

		for (i=0; i<=31; i++) 
			linux_regs->lgpr[i] = regs->fixreg[i];
		linux_regs->lnip = regs->pc;
		linux_regs->lmsr = 0;
		/* XXX Is that right? */
		linux_regs->lorig_gpr3 = regs->fixreg[3];
		linux_regs->lctr = regs->ctr;
		linux_regs->llink = regs->lr;
		linux_regs->lxer = regs->xer;
		linux_regs->lccr = regs->cr;
		linux_regs->lmq = 0; 
		linux_regs->ltrap = 0;
		linux_regs->ldar = 0;
		linux_regs->ldsisr = 0;
		linux_regs->lresult = 0;

		error = copyout(linux_regs, (caddr_t)SCARG(uap, data),
			 sizeof(struct linux_pt_regs));
		goto out;

	case  LINUX_PTRACE_SETREGS:
		MALLOC(regs, struct reg*, sizeof(struct reg), M_TEMP, M_WAITOK);
		MALLOC(linux_regs, struct linux_pt_regs*, sizeof(*linux_regs),
		    M_TEMP, M_WAITOK);

		error = copyin((caddr_t)SCARG(uap, data), linux_regs,
			 sizeof(struct linux_pt_regs));
		if (error != 0)
			goto out;

		for (i=0; i<=31; i++) 
			regs->fixreg[i] = linux_regs->lgpr[i];
		regs->lr = linux_regs->llink;
		regs->cr = linux_regs->lccr;
		regs->xer = linux_regs->lxer;
		regs->ctr = linux_regs->lctr;
		regs->pc = linux_regs->lnip; /* XXX */

		error = process_write_regs(lt, regs);
		goto out;

	case  LINUX_PTRACE_GETFPREGS:
		MALLOC(fpregs, struct fpreg *, sizeof(struct fpreg),
		    M_TEMP, M_WAITOK);
		MALLOC(linux_fpreg, double *,
		    32*sizeof(double), M_TEMP, M_WAITOK);

		error = process_read_fpregs(lt, fpregs);
		if (error != 0)
			goto out;

		/* zero the contents if NetBSD fpreg structure is smaller */
		if (sizeof(struct fpreg) < (32*sizeof(double)))
			memset(linux_fpreg, '\0', (32*sizeof(double)));

		memcpy(linux_fpreg, fpregs,
			min(32*sizeof(double), sizeof(struct fpreg)));
		error = copyout(linux_fpreg, (caddr_t)SCARG(uap, data),
			 32*sizeof(double));
		goto out;

	case  LINUX_PTRACE_SETFPREGS:
		MALLOC(fpregs, struct fpreg *, sizeof(struct fpreg),
		    M_TEMP, M_WAITOK);
		MALLOC(linux_fpreg, double *,
		    32*sizeof(double), M_TEMP, M_WAITOK);
		error = copyin((caddr_t)SCARG(uap, data), linux_fpreg,
			 32*sizeof(double));
		if (error != 0)
			goto out;

		memset(fpregs, '\0', sizeof(struct fpreg));
		memcpy(fpregs, linux_fpreg,
		    min(32*sizeof(double), sizeof(struct fpreg)));

		error = process_write_fpregs(lt, fpregs);
		goto out;

	case  LINUX_PTRACE_PEEKUSR:
		addr = SCARG(uap, addr);
		MALLOC(regs, struct reg*, sizeof(struct reg), M_TEMP, M_WAITOK);
		error = process_read_regs(lt, regs);
		if (error)
			goto out;

		PHOLD(lt);	/* need full process info */
		error = 0;
		if ((addr < LUSR_OFF(lusr_startgdb)) || 
		    (addr > LUSR_OFF(lu_comm_end))) 
		 	error = 1;
		else if (addr == LUSR_OFF(u_tsize))
			*retval = p->p_vmspace->vm_tsize;
		else if (addr == LUSR_OFF(u_dsize))
			*retval = p->p_vmspace->vm_dsize;
		else if (addr == LUSR_OFF(u_ssize))
			*retval = p->p_vmspace->vm_ssize;
		else if (addr == LUSR_OFF(start_code))
			*retval = (register_t) p->p_vmspace->vm_taddr;
		else if (addr == LUSR_OFF(start_stack))
			*retval = (register_t) p->p_vmspace->vm_minsaddr;
		else if ((addr >= LUSR_REG_OFF(lpt_regs_fixreg_begin)) && 
		    (addr <= LUSR_REG_OFF(lpt_regs_fixreg_end)))
			*retval = regs->fixreg[addr / sizeof (register_t)];
		else if (addr == LUSR_REG_OFF(lnip))
			*retval = regs->pc;
		else if (addr == LUSR_REG_OFF(lctr))
			*retval = regs->ctr;
		else if (addr == LUSR_REG_OFF(llink))
			*retval = regs->lr;
		else if (addr == LUSR_REG_OFF(lxer))
			*retval = regs->xer;
		else if (addr == LUSR_REG_OFF(lccr))
			*retval = regs->cr;
		else if (addr == LUSR_OFF(signal))
			error = 1;
		else if (addr == LUSR_OFF(signal))
			error = 1;
		else if (addr == LUSR_OFF(magic))
			error = 1;
		else if (addr == LUSR_OFF(u_comm))
			error = 1;
		else {
#ifdef DEBUG_LINUX
			printf("linux_ptrace: unsupported address: %d\n", addr);
#endif
			error = 1;
		}

		PRELE(lt);

		if (error)
			goto out;

		error = copyout (retval, 
		    (caddr_t)SCARG(uap, data), sizeof retval);
		*retval = SCARG(uap, data);

		goto out;

		break;

	case  LINUX_PTRACE_POKEUSR: /* XXX Not tested */
		addr = SCARG(uap, addr);
		MALLOC(regs, struct reg*, sizeof(struct reg), M_TEMP, M_WAITOK);
		error = process_read_regs(lt, regs);
		if (error)
			goto out;

		PHOLD(lt);       /* need full process info */
		error = 0;
		if ((addr < LUSR_OFF(lusr_startgdb)) || 
		    (addr > LUSR_OFF(lu_comm_end)))
		 	error = 1;
		else if (addr == LUSR_OFF(u_tsize))
			error = 1;
		else if (addr == LUSR_OFF(u_dsize))
			error = 1;
		else if (addr == LUSR_OFF(u_ssize))
			error = 1;
		else if (addr == LUSR_OFF(start_code))
			error = 1;
		else if (addr == LUSR_OFF(start_stack))
			error = 1;
		else if ((addr >= LUSR_REG_OFF(lpt_regs_fixreg_begin)) && 
		    (addr <= LUSR_REG_OFF(lpt_regs_fixreg_end)))
			regs->fixreg[addr / sizeof (register_t)] = 
			    (register_t)SCARG(uap, data);
		else if (addr == LUSR_REG_OFF(lnip))
			regs->pc = (register_t)SCARG(uap, data);
		else if (addr == LUSR_REG_OFF(lctr))
			regs->ctr = (register_t)SCARG(uap, data);
		else if (addr == LUSR_REG_OFF(llink))
			regs->lr = (register_t)SCARG(uap, data);
		else if (addr == LUSR_REG_OFF(lxer))
			regs->xer = (register_t)SCARG(uap, data);
		else if (addr == LUSR_REG_OFF(lccr))
			regs->cr = (register_t)SCARG(uap, data);
		else if (addr == LUSR_OFF(signal))
			error = 1;
		else if (addr == LUSR_OFF(magic))
			error = 1;
		else if (addr == LUSR_OFF(u_comm))
			error = 1;
		else {
#ifdef DEBUG_LINUX
			printf("linux_ptrace: unsupported address: %d\n", addr);
#endif
			error = 1;
		}

		PRELE(lt);

		error = process_write_regs(lt,regs);
		if (error) 
			goto out;

		break;
	default:
		/* never reached */
		break;
	}
	return EIO;

	 out:
	if (regs)
		FREE(regs, M_TEMP);
	if (fpregs)
		FREE(fpregs, M_TEMP);
	if (linux_regs)
		FREE(linux_regs, M_TEMP);
	if (linux_fpreg)
		FREE(linux_fpreg, M_TEMP);
	return (error);
}
