xref: /illumos-gate/usr/src/cmd/sgs/librtld_db/sparc/plt32_resolution.c (revision 9164a50bf932130cbb5097a16f6986873ce0e6e5)
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, Version 1.0 only
6  * (the "License").  You may not use this file except in compliance
7  * with the License.
8  *
9  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
10  * or http://www.opensolaris.org/os/licensing.
11  * See the License for the specific language governing permissions
12  * and limitations under the License.
13  *
14  * When distributing Covered Code, include this CDDL HEADER in each
15  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
16  * If applicable, add the following below this CDDL HEADER, with the
17  * fields enclosed by brackets "[]" replaced with your own identifying
18  * information: Portions Copyright [yyyy] [name of copyright owner]
19  *
20  * CDDL HEADER END
21  */
22 /*
23  * Copyright 2004 Sun Microsystems, Inc.  All rights reserved.
24  * Use is subject to license terms.
25  */
26 
27 #include	<stdio.h>
28 #include	<proc_service.h>
29 #include	<link.h>
30 #include	<rtld_db.h>
31 #include	<_rtld_db.h>
32 #include	<msg.h>
33 
34 
35 /*
36  * A un-initialized PLT look like so:
37  *
38  * .PLT
39  *	sethi	(.-.PLT0), %g1
40  *	ba,a	.PLT0
41  *	nop
42  *
43  * To test to see if this is an uninitialized PLT we check
44  * the second instruction and confirm that it's a branch.
45  */
46 /* ARGSUSED 2 */
47 rd_err_e
48 plt32_resolution(rd_agent_t *rap, psaddr_t pc, lwpid_t lwpid,
49 	psaddr_t pltbase, rd_plt_info_t *rpi)
50 {
51 	unsigned int	instr[4];
52 	rd_err_e	rerr;
53 	psaddr_t	destaddr = 0;
54 	psaddr_t	pltoff, pltaddr;
55 	int		pltbound = 0;
56 
57 	pltoff = pc - pltbase;
58 	pltaddr = pltbase +
59 		((pltoff / M32_PLT_ENTSIZE) * M32_PLT_ENTSIZE);
60 
61 	if (ps_pread(rap->rd_psp, pltaddr, (char *)instr,
62 	    M32_PLT_ENTSIZE) != PS_OK) {
63 		LOG(ps_plog(MSG_ORIG(MSG_DB_READFAIL_2), EC_ADDR(pltaddr)));
64 		return (RD_ERR);
65 	}
66 
67 	if (rtld_db_version >= RD_VERSION3) {
68 		rpi->pi_flags = 0;
69 		rpi->pi_baddr = 0;
70 	}
71 
72 	if ((instr[0] != M_NOP) &&
73 	    ((instr[1] & (~(S_MASK(22)))) == M_BA_A)) {
74 		/*
75 		 * Unbound PLT
76 		 */
77 		if ((rerr = rd_binder_exit_addr(rap, MSG_ORIG(MSG_SYM_RTBIND),
78 		    &(rpi->pi_target))) != RD_OK) {
79 			return (rerr);
80 		}
81 		rpi->pi_skip_method = RD_RESOLVE_TARGET_STEP;
82 		rpi->pi_nstep = 1;
83 	} else if ((instr[2] & (~(S_MASK(13)))) == M_JMPL) {
84 		/*
85 		 * Resolved 32-bit PLT entry format (full-32):
86 		 *
87 		 * .PLT:
88 		 * 0	sethi	(.-PLT0), %g1
89 		 * 1	sethi	%hi(dest), %g1
90 		 * 2	jmpl	%g1 + lo(dest), %g0
91 		 * 3	nop
92 		 */
93 		rpi->pi_skip_method = RD_RESOLVE_STEP;
94 		rpi->pi_nstep = 4;
95 		rpi->pi_target = 0;
96 		if (rtld_db_version >= RD_VERSION3) {
97 			uint_t		hi_bits;
98 			uint_t		lo_bits;
99 			hi_bits = instr[1] & S_MASK(22); /* 31..10 */
100 			lo_bits = instr[2] & S_MASK(10); /* 09..00 */
101 			destaddr = (hi_bits << 10) | lo_bits;
102 			pltbound++;
103 		}
104 	} else  if ((instr[0] == M_NOP) &&
105 	    ((instr[1] & (~(S_MASK(22)))) == M_BA_A)) {
106 		/*
107 		 * Resolved 32-bit PLT entry format (b+-8mb):
108 		 * .PLT
109 		 * 0	nop
110 		 * 1	ba,a	<dest>
111 		 * 2	nop
112 		 * 3	nop
113 		 */
114 		rpi->pi_skip_method = RD_RESOLVE_STEP;
115 		rpi->pi_nstep = 2;
116 		rpi->pi_target = 0;
117 		if (rtld_db_version >= RD_VERSION3) {
118 			uint_t	d22;
119 			d22 = instr[1] & S_MASK(22);
120 			destaddr = ((int)pltaddr + 4) +
121 				(((int)d22 << 10) >> 8);
122 			pltbound++;
123 		}
124 	} else if ((instr[0] == M_NOP) &&
125 	    ((instr[1] & (~(S_MASK(19)))) == M_BA_A_PT)) {
126 		/*
127 		 * Resolved 32-bit PLT entry format (b+-2mb):
128 		 * .PLT
129 		 * 0	nop
130 		 * 1	ba,a,pt	%icc, <dest>
131 		 * 2	nop
132 		 * 3	nop
133 		 */
134 		rpi->pi_skip_method = RD_RESOLVE_STEP;
135 		rpi->pi_nstep = 2;
136 		rpi->pi_target = 0;
137 		if (rtld_db_version >= RD_VERSION3) {
138 			uint_t	d19;
139 			d19 = instr[1] & S_MASK(22);
140 			destaddr = ((int)pltaddr + 4) +
141 				(((int)d19 << 13) >> 11);
142 			pltbound++;
143 		}
144 	} else
145 		rpi->pi_skip_method = RD_RESOLVE_NONE;
146 
147 	if ((rtld_db_version >= RD_VERSION3) && pltbound) {
148 		rpi->pi_flags |= RD_FLG_PI_PLTBOUND;
149 		rpi->pi_baddr = destaddr;
150 	}
151 	return (RD_OK);
152 }
153