rtld_start.S revision 1.11
1 /* $NetBSD: rtld_start.S,v 1.11 2002/09/11 18:18:37 mycroft Exp $ */ 2 3 /* 4 * Copyright 1996 Matt Thomas <matt (at) 3am-software.com> 5 * All rights reserved. 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 10 * 1. Redistributions of source code must retain the above copyright 11 * notice, this list of conditions and the following disclaimer. 12 * 2. Redistributions in binary form must reproduce the above copyright 13 * notice, this list of conditions and the following disclaimer in the 14 * documentation and/or other materials provided with the distribution. 15 * 3. The name of the author may not be used to endorse or promote products 16 * derived from this software without specific prior written permission. 17 * 18 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 19 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 20 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 21 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 22 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 23 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 24 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 25 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 26 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 27 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 28 */ 29 30 #include <machine/asm.h> 31 32 .extern _GLOBAL_OFFSET_TABLE_ 33 34 /* 35 * Note: we can call ourselves LEAF even though we use callee-saved 36 * registers because we're the root of the call graph. 37 */ 38 LEAF_NOPROFILE(_rtld_start, 0) 39 .set noreorder 40 br pv, 1f 41 1: LDGP(pv) 42 43 /* 44 * Relocate ourself. 45 */ 46 br t2, 2f /* get our PC */ 47 2: ldiq t3, 2b /* get where the linker thought we were */ 48 subq t2, t3, a1 /* calculate the displacement */ 49 50 lda t5, _DYNAMIC 51 addq a1, t5, a0 /* add the displacement */ 52 53 bsr ra, _rtld_relocate_nonplt_self 54 LDGP(ra) 55 56 /* 57 * Allocate space on the stack for the cleanup and obj_main 58 * entries that _rtld() will provide for us. 59 */ 60 lda sp, -16(sp) 61 62 mov sp, a0 /* v0 = _rtld(sp); */ 63 CALL(_rtld) 64 65 ldq a1, 0(sp) /* cleanup */ 66 ldq a2, 8(sp) /* obj_main */ 67 lda sp, 16(sp) /* pop stack */ 68 69 mov sp, a0 /* stack pointer */ 70 mov s0, a3 /* ps_strings */ 71 72 mov v0, pv /* set up PV for entry point */ 73 74 jsr ra, (v0), 0 /* (*_start)(sp, cleanup, obj, ps_strings); */ 75 ldgp gp, 0(ra) 76 77 CALL(exit) 78 halt 79 END(_rtld_start) 80 81 #define RTLD_BIND_START_PROLOGUE \ 82 /* at_reg already used by PLT code. */ \ 83 .set noat ; \ 84 \ 85 /* \ 86 * Allocate stack frame and preserve all registers that the \ 87 * caller would have normally saved themselves. \ 88 */ \ 89 lda sp, -168(sp) ; \ 90 stq ra, 0(sp) ; \ 91 stq v0, 8(sp) ; \ 92 stq t0, 16(sp) ; \ 93 stq t1, 24(sp) ; \ 94 stq t2, 32(sp) ; \ 95 stq t3, 40(sp) ; \ 96 stq t4, 48(sp) ; \ 97 stq t5, 56(sp) ; \ 98 stq t6, 64(sp) ; \ 99 stq t7, 72(sp) ; \ 100 stq a0, 80(sp) ; \ 101 stq a1, 88(sp) ; \ 102 stq a2, 96(sp) ; \ 103 stq a3, 104(sp) ; \ 104 stq a4, 112(sp) ; \ 105 stq a5, 120(sp) ; \ 106 stq t8, 128(sp) ; \ 107 stq t9, 136(sp) ; \ 108 stq t10, 144(sp) ; \ 109 stq t11, 152(sp) ; \ 110 stq gp, 160(sp) ; \ 111 \ 112 /* \ 113 * Load our global pointer. Note, can't use pv, since it is \ 114 * already used by the PLT code. \ 115 */ \ 116 br t0, 1f ; \ 117 1: LDGP(t0) 118 119 #define RTLD_BIND_START_EPILOGUE \ 120 /* Move the destination address into position. */ \ 121 mov v0, pv ; \ 122 \ 123 /* Restore program registers. */ \ 124 ldq ra, 0(sp) ; \ 125 ldq v0, 8(sp) ; \ 126 ldq t0, 16(sp) ; \ 127 ldq t1, 24(sp) ; \ 128 ldq t2, 32(sp) ; \ 129 ldq t3, 40(sp) ; \ 130 ldq t4, 48(sp) ; \ 131 ldq t5, 56(sp) ; \ 132 ldq t6, 64(sp) ; \ 133 ldq t7, 72(sp) ; \ 134 ldq a0, 80(sp) ; \ 135 ldq a1, 88(sp) ; \ 136 ldq a2, 96(sp) ; \ 137 ldq a3, 104(sp) ; \ 138 ldq a4, 112(sp) ; \ 139 ldq a5, 120(sp) ; \ 140 ldq t8, 128(sp) ; \ 141 ldq t9, 136(sp) ; \ 142 ldq t10, 144(sp) ; \ 143 ldq t11, 152(sp) ; \ 144 ldq gp, 160(sp) ; \ 145 /* XXX LDGP? */ \ 146 \ 147 /* \ 148 * We've patched the PLT; sync the I-stream. \ 149 */ \ 150 imb ; \ 151 \ 152 /* Pop the stack frame and turn control to the destination. */ \ 153 lda sp, 168(sp) ; \ 154 jmp zero, (pv) 155 156 /* 157 * Lazy binding entry point, called via PLT. 158 */ 159 NESTED_NOPROFILE(_rtld_bind_start, 0, 168, ra, 0, 0) 160 161 RTLD_BIND_START_PROLOGUE 162 163 /* Set up the arguments for _rtld_bind. */ 164 subq at_reg, pv, a1 /* calculate offset of reloc entry */ 165 ldq a0, 8(pv) /* object structure */ 166 subq a1, 20, a1 /* = (at - pv - 20) / 12 * 24 */ 167 addq a1, a1, a1 168 169 CALL(_rtld_bind) 170 171 RTLD_BIND_START_EPILOGUE 172 173 END(_rtld_bind_start) 174 175 /* 176 * Lazy binding entry point, called via PLT. This version is for the 177 * old PLT entry format. 178 */ 179 NESTED_NOPROFILE(_rtld_bind_start_old, 0, 168, ra, 0, 0) 180 181 RTLD_BIND_START_PROLOGUE 182 183 /* Set up the arguments for _rtld_bind. */ 184 ldq a0, 8(pv) /* object structure */ 185 mov at_reg, a1 /* offset of reloc entry */ 186 187 CALL(_rtld_bind) 188 189 RTLD_BIND_START_EPILOGUE 190 191 END(_rtld_bind_start_old) 192
Indexes created Thu Oct 02 14:10:14 GMT 2025