usr/src/common/dtrace/dtrace_data.c

/*
 * CDDL HEADER START
 *
 * The contents of this file are subject to the terms of the
 * Common Development and Distribution License (the "License").
 * You may not use this file except in compliance with the License.
 *
 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
 * or http://www.opensolaris.org/os/licensing.
 * See the License for the specific language governing permissions
 * and limitations under the License.
 *
 * When distributing Covered Code, include this CDDL HEADER in each
 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
 * If applicable, add the following below this CDDL HEADER, with the
 * fields enclosed by brackets "[]" replaced with your own identifying
 * information: Portions Copyright [yyyy] [name of copyright owner]
 *
 * CDDL HEADER END
 */

/*
 * Copyright 2007 Sun Microsystems, Inc.  All rights reserved.
 * Use is subject to license terms.
 */

#pragma ident	"%Z%%M%	%I%	%E% SMI"

#include <sys/types.h>

/*
 * In order to let the DTrace fasttrap provider trace processes before libc
 * is initialized, we place this structure in the thread pointer register.
 * This is communicated to the kernel (in the elfexec() function) by
 * placing the address of this structure in the PT_SUNWDTRACE program
 * header with the -zdtrace_data=<object> option to ld(1).
 *
 * Besides DTrace use, the initialization sequence carried out for the
 * PT_SUNWDTRACE data is an essential step required for the correct
 * initialization of any process.  Therefore, PT_SUNWDTRACE data must
 * exist in any interpretor available on Solaris.
 *
 * ld.so.1 is the standard interpretor on all Solaris platforms.  However,
 * for ABI compliance, 32-bit executables are able to identify libc.so.1
 * as their interpretor.  Therefore, this data file is used to build all
 * instances of ld.so.1, and the 32-bit versions of libc.so.1.  Note,
 * although libc.so.1 can act as an interpretor for 32-bit applications,
 * libc.so.1 only provides a bootstrap mechanism to load and jump to
 * ld.so.1.
 *
 * The fields of the program header are set as follows:
 *	p_type:         PT_SUNWDTRACE
 *	p_vaddr:        address of dtrace_data
 *	p_memsz:        size of dtrace_data
 *	p_flags:        flags of segment dtrace_data is assigned to
 *	p_paddr:        <reserved>
 *	p_filesz:       <reserved>
 *	p_offset:       <reserved>
 *	p_align:        <reserved>
 *
 * See the comment in fasttrap.h for information on how to safely change
 * this data structure and the other places that need to be kept in sync.
 */

#if defined(__sparc)

#pragma align 64(dtrace_data)
uint32_t	dtrace_data[32] = {
	0, 0, 0, 0, 0, 0, 0, 0,
	0, 0, 0, 0, 0, 0, 0, 0,
	0x9de04000,			/* save %g1, %g0, %sp */
	0x81e80000,			/* restore %g0, %g0, %g0 */
	0x91d0203a,			/* ta 0x3a */
	0x81ca0000,			/* return %o0 */
	0, 0,				/* self pointer (must be zero) */
	0, 0,
	0, 0, 0, 0, 0, 0, 0, 0
};

#elif defined(__amd64)

#pragma align 64(dtrace_data)
uint8_t	dtrace_data[64] = {
	0, 0, 0, 0, 0, 0, 0, 0,		/* self pointer (must be zero) */
	0, 0, 0, 0, 0, 0, 0, 0,
	0, 0, 0, 0, 0, 0, 0, 0,
	0, 0, 0, 0, 0, 0, 0, 0,
	0, 0, 0, 0, 0, 0, 0, 0,
	0, 0, 0, 0, 0, 0, 0, 0,
	0, 0, 0, 0, 0, 0, 0, 0,
	0, 0, 0, 0, 0, 0, 0, 0
};

#elif defined(__i386)

#pragma align 64(dtrace_data)
uint8_t	dtrace_data[64] = {
	0, 0, 0, 0,			/* self pointer (must be zero)  */
	0, 0, 0, 0,
	0, 0, 0, 0, 0, 0, 0, 0,
	0, 0, 0, 0, 0, 0, 0, 0,
	0, 0, 0, 0, 0, 0, 0, 0,
	0, 0, 0, 0, 0, 0, 0, 0,
	0, 0, 0, 0, 0, 0, 0, 0,
	0, 0, 0, 0, 0, 0, 0, 0,
	0, 0, 0, 0, 0, 0, 0, 0
};

#else

#error "unknown ISA"

#endif