xref: /illumos-gate/usr/src/cmd/sgs/rtld/amd64/dlamd64getunwind.c (revision f441771b)

/*
 * 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 (c) 2004, 2010, Oracle and/or its affiliates. All rights reserved.
 */

#include	<string.h>
#include	<dlfcn.h>
#include	<stdio.h>
#include	<debug.h>
#include	"_rtld.h"
#include	"_elf.h"
#include	"_inline_gen.h"
#include	"msg.h"


static Dl_amd64_unwindinfo *
getunwind_core(Lm_list *lml, void *pc, Dl_amd64_unwindinfo *unwindinfo)
{
	Rt_map	*lmp;

	/*
	 * Validate the version information.
	 */
	if (unwindinfo == NULL) {
		eprintf(lml, ERR_FATAL, MSG_INTL(MSG_ARG_ILLVAL));
		return (0);
	}
	if ((unwindinfo->dlui_version < DLUI_VERS_1) ||
	    (unwindinfo->dlui_version > DLUI_VERS_CURRENT)) {
		eprintf(lml, ERR_FATAL, MSG_INTL(MSG_UNW_BADVERS),
		    unwindinfo->dlui_version, DLUI_VERS_CURRENT);
		return (0);
	}

	/*
	 * Clean out the structure.
	 */
	unwindinfo->dlui_flags = 0;
	unwindinfo->dlui_objname = 0;
	unwindinfo->dlui_unwindstart = 0;
	unwindinfo->dlui_unwindend = 0;
	unwindinfo->dlui_segstart = 0;
	unwindinfo->dlui_segend = 0;

	/*
	 * Identify the link-map associated with the exception "pc".  Note,
	 * the "pc" might not correspond to a link-map (as can happen with a
	 * "pc" fabricated by a debugger such as dbx).  In this case, the
	 * unwind data buffer will be filled with flags set to indicate an
	 * unknown caller.
	 */
	lmp = _caller(pc, CL_NONE);

	if (lmp) {
		mmapobj_result_t	*mpp;

		/*
		 * Determine the associated segment.
		 */
		if ((mpp = find_segment(pc, lmp)) == NULL)
			return (0);

		unwindinfo->dlui_objname = (char *)PATHNAME(lmp);
		unwindinfo->dlui_segstart = mpp->mr_addr;
		unwindinfo->dlui_segend = mpp->mr_addr + mpp->mr_msize;

		if (PTUNWIND(lmp) && (mpp->mr_addr)) {
			uintptr_t   base;

			if (FLAGS(lmp) & FLG_RT_FIXED)
				base = 0;
			else
				base = ADDR(lmp);

			unwindinfo->dlui_unwindstart =
			    (void *)(PTUNWIND(lmp)->p_vaddr + base);
			unwindinfo->dlui_unwindend =
			    (void *)(PTUNWIND(lmp)->p_vaddr +
			    PTUNWIND(lmp)->p_memsz + base);

		} else if (mpp->mr_addr)
			unwindinfo->dlui_flags |= DLUI_FLG_NOUNWIND;
		else
			unwindinfo->dlui_flags |=
			    DLUI_FLG_NOUNWIND | DLUI_FLG_NOOBJ;
	} else {
		/*
		 * No object found.
		 */
		unwindinfo->dlui_flags = DLUI_FLG_NOOBJ | DLUI_FLG_NOUNWIND;
	}
	return (unwindinfo);
}

#pragma weak _dlamd64getunwind = dlamd64getunwind

Dl_amd64_unwindinfo *
dlamd64getunwind(void *pc, Dl_amd64_unwindinfo *unwindinfo)
{
	Rt_map	*lmp;
	Lm_list	*lml;
	int	entry = enter(0);

	lmp = _caller(caller(), CL_EXECDEF);
	lml = LIST(lmp);

	unwindinfo = getunwind_core(lml, pc, unwindinfo);

	if (entry)
		leave(lml, 0);
	return (unwindinfo);
}