s10_npreload.c revision 12808:eb600d5471d5 
1/*
2 * CDDL HEADER START
3 *
4 * The contents of this file are subject to the terms of the
5 * Common Development and Distribution License (the "License").
6 * You may not use this file except in compliance with the License.
7 *
8 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
9 * or http://www.opensolaris.org/os/licensing.
10 * See the License for the specific language governing permissions
11 * and limitations under the License.
12 *
13 * When distributing Covered Code, include this CDDL HEADER in each
14 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
15 * If applicable, add the following below this CDDL HEADER, with the
16 * fields enclosed by brackets "[]" replaced with your own identifying
17 * information: Portions Copyright [yyyy] [name of copyright owner]
18 *
19 * CDDL HEADER END
20 */
21
22/*
23 * Copyright (c) 2009, 2010, Oracle and/or its affiliates. All rights reserved.
24 */
25
26#pragma init(init)
27
28#include <s10_brand.h>
29#include <stdlib.h>
30#include <sys/syscall.h>
31#include <dlfcn.h>
32#include <link.h>
33#include <limits.h>
34#include <sys/mman.h>
35#include <strings.h>
36
37/* MAXCOMLEN is only defined in user.h in the kernel. */
38#define	MAXCOMLEN	16
39
40/*
41 * This is a library that is LD_PRELOADed into native processes.
42 * Its primary function is to perform one brand operation, B_S10_NATIVE,
43 * which checks that this is actually a native process.  If it is, then
44 * the operation changes the executable name so that it is no longer
45 * ld.so.1.  Instead it changes it to be the name of the real native
46 * executable that we're runnning.  This allows things like pgrep to work
47 * as expected.  Note that this brand operation only changes the process
48 * name wrt the kernel.  From the process' perspective, AT_SUN_EXECNAME is
49 * still ld.so.1. ld.so.1 removes itself and its arguments from the argv list.
50 */
51void
52init(void)
53{
54	int i;
55	Dl_argsinfo_t argsinfo;
56	sysret_t rval;
57	char	*pcomm;
58	char	cmd_buf[MAXCOMLEN + 1];
59	char	arg_buf[PSARGSZ];
60
61	if (dlinfo(RTLD_SELF, RTLD_DI_ARGSINFO, &argsinfo) == -1)
62		return;
63
64	/* get the base cmd name */
65	if ((pcomm = strrchr(argsinfo.dla_argv[0], '/')) != NULL)
66		pcomm = pcomm + 1;
67	else
68		pcomm = argsinfo.dla_argv[0];
69	(void) strlcpy(cmd_buf, pcomm, sizeof (cmd_buf));
70
71	(void) strlcpy(arg_buf, argsinfo.dla_argv[0], sizeof (arg_buf));
72
73	for (i = 1; i < argsinfo.dla_argc; i++) {
74		(void) strlcat(arg_buf, " ", sizeof (arg_buf));
75		if (strlcat(arg_buf, argsinfo.dla_argv[i], sizeof (arg_buf))
76		    >= sizeof (arg_buf))
77			break;
78	}
79
80	(void) __systemcall(&rval, SYS_brand, B_S10_NATIVE, cmd_buf, arg_buf);
81}
82