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 #pragma ident "%Z%%M% %I% %E% SMI" 28 29 #include <libelf.h> 30 #include <sys/reg.h> 31 #include <rtld_db.h> 32 #include "_rtld_db.h" 33 #include "msg.h" 34 35 36 /* 37 * On amd64, basically, a PLT entry looks like this: 38 * 39 * 0x00 ff 25 00 00 00 00 jmpq *func@got(%rip) ; jmp GOT[N] 40 * 0x06 68 01 00 00 00 pushq $0x1 ; push index 41 * 0x0b e9 00 00 00 00 jmpq .plt0 ; jmp plt[0] 42 * 0x10 ... 43 * 44 * The first time around GOT[N] contains address of pushq; this forces 45 * first time resolution to go thru PLT's first entry (which is a call) 46 * The nth time around, the GOT[N] actually contains the resolved 47 * address of the symbol(name), so the jmp is direct 48 */ 49 /* ARGSUSED 3 */ 50 rd_err_e 51 plt64_resolution(rd_agent_t *rap, psaddr_t pc, lwpid_t lwpid, 52 psaddr_t pltbase, rd_plt_info_t *rpi) 53 { 54 uint32_t pcrel; 55 psaddr_t destaddr; 56 psaddr_t pltoff, pltaddr; 57 prgregset_t gr; 58 59 60 if (rtld_db_version >= RD_VERSION3) { 61 rpi->pi_flags = 0; 62 rpi->pi_baddr = 0; 63 } 64 65 pltoff = pc - pltbase; 66 pltaddr = pltbase + 67 ((pltoff / M_PLT_ENTSIZE) * M_PLT_ENTSIZE); 68 /* 69 * This is the target of the jmp instruction 70 */ 71 if (ps_pread(rap->rd_psp, pltaddr + 2, (char *)&pcrel, 72 sizeof (pcrel)) != PS_OK) { 73 LOG(ps_plog(MSG_ORIG(MSG_DB_READFAIL_2), EC_ADDR(pltaddr + 2))); 74 return (RD_ERR); 75 } 76 77 /* 78 * the offset to the GOT table entry is 79 * PC-relative. 80 */ 81 destaddr = pcrel + pltaddr + 6; 82 83 /* 84 * Find out what's pointed to by @OFFSET_INTO_GOT 85 */ 86 if (ps_pread(rap->rd_psp, destaddr, (char *)&destaddr, 87 sizeof (destaddr)) != PS_OK) { 88 LOG(ps_plog(MSG_ORIG(MSG_DB_READFAIL_2), EC_ADDR(destaddr))); 89 return (RD_ERR); 90 } 91 if (destaddr == (pltaddr + 6)) { 92 rd_err_e rerr; 93 /* 94 * If GOT[ind] points to PLT+6 then this is the first 95 * time through this PLT. 96 */ 97 if ((rerr = rd_binder_exit_addr(rap, MSG_ORIG(MSG_SYM_RTBIND), 98 &(rpi->pi_target))) != RD_OK) { 99 return (rerr); 100 } 101 rpi->pi_skip_method = RD_RESOLVE_TARGET_STEP; 102 rpi->pi_nstep = 1; 103 } else { 104 /* 105 * This is the n'th time through and GOT[ind] points 106 * to the final destination. 107 */ 108 rpi->pi_skip_method = RD_RESOLVE_STEP; 109 rpi->pi_nstep = 1; 110 rpi->pi_target = 0; 111 if (rtld_db_version >= RD_VERSION3) { 112 rpi->pi_flags |= RD_FLG_PI_PLTBOUND; 113 rpi->pi_baddr = destaddr; 114 } 115 } 116 117 return (RD_OK); 118 } 119