ldasm.S revision 1.21
1/* $OpenBSD: ldasm.S,v 1.21 2003/08/12 18:53:44 jason Exp $ */ 2/* $NetBSD: rtld_start.S,v 1.5 2001/08/14 22:17:48 eeh Exp $ */ 3 4/* 5 * Copyright (c) 2001 Jason L. Wright (jason@thought.net) 6 * All rights reserved. 7 * 8 * Redistribution and use in source and binary forms, with or without 9 * modification, are permitted provided that the following conditions 10 * are met: 11 * 1. Redistributions of source code must retain the above copyright 12 * notice, this list of conditions and the following disclaimer. 13 * 2. Redistributions in binary form must reproduce the above copyright 14 * notice, this list of conditions and the following disclaimer in the 15 * documentation and/or other materials provided with the distribution. 16 * 17 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 18 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED 19 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE 20 * DISCLAIMED. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, 21 * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES 22 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR 23 * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 24 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, 25 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN 26 * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 27 * POSSIBILITY OF SUCH DAMAGE. 28 */ 29 30/*- 31 * Copyright (c) 2000 Eduardo Horvath. 32 * Copyright (c) 1999 The NetBSD Foundation, Inc. 33 * All rights reserved. 34 * 35 * This code is derived from software contributed to The NetBSD Foundation 36 * by Christos Zoulas and Paul Kranenburg. 37 * 38 * Redistribution and use in source and binary forms, with or without 39 * modification, are permitted provided that the following conditions 40 * are met: 41 * 1. Redistributions of source code must retain the above copyright 42 * notice, this list of conditions and the following disclaimer. 43 * 2. Redistributions in binary form must reproduce the above copyright 44 * notice, this list of conditions and the following disclaimer in the 45 * documentation and/or other materials provided with the distribution. 46 * 3. All advertising materials mentioning features or use of this software 47 * must display the following acknowledgement: 48 * This product includes software developed by the NetBSD 49 * Foundation, Inc. and its contributors. 50 * 4. Neither the name of The NetBSD Foundation nor the names of its 51 * contributors may be used to endorse or promote products derived 52 * from this software without specific prior written permission. 53 * 54 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS 55 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED 56 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 57 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS 58 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 59 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 60 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 61 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 62 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 63 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 64 * POSSIBILITY OF SUCH DAMAGE. 65 */ 66 67#include <sys/syscall.h> 68#include <machine/trap.h> 69#include <machine/asm.h> 70#define _LOCORE 71#include <machine/frame.h> 72 73/* 74 * ELF: 75 * On startup the stack should contain 16 extended word register save 76 * area, followed by the arg count, etc. 77 * 78 * _rtld() expects the stack pointer to point to two longwords for argument 79 * return followed by argc, etc. We need to create a pointer to 80 * &argc + 16 and pass that in. The return args will be in those 81 * locations. 82 * 83 * NB: We are violating the ELF spec by passing a pointer to the ps strings in 84 * %g1 instead of a termination routine. 85 */ 86 87/* Offset of ARGC from bottom of stack */ 88#define ARGC (16*8) 89/* XXX - DL_DATA_SIZE should be (9*8), but I can't think right now. */ 90#define DL_DATA_SIZE (16*8) 91 92 .section ".text" 93 .align 16 94 95_ENTRY(_dl_start) 96 sub %g0, %g0, %fp ! clear frame 97 mov %g1, %l1 ! save ps_strings 98 sub %sp, DL_DATA_SIZE, %sp ! make room for dl_data 99 add %sp, BIAS + ARGC, %l3 100 101 add %l3, DL_DATA_SIZE, %o0 102 mov %o0, %l0 103 104 /* 105 * need to figure out where _DYNAMIC is located, newer binutils 106 * does not fill in GOT to read _DYNAMIC before relocation. 107 */ 108 call 0f 109 nop 110 call _DYNAMIC+8 ! not executed (no delay needed) 1110: ld [%o7+8], %o2 ! load stub call instruction 112 sll %o2, 2, %o2 ! extract PC offset 113 sra %o2, 0, %o2 ! sign-extend 114 115 add %o2, %o7, %o2 ! real &_DYNAMIC 116 117 call _dl_boot_bind ! _dl_boot_bind(sp,dl_data,dynamicp) 118 mov %l3, %o1 119 120 mov %l3, %o3 121 ldx [%l0], %l3 ! argc = *sp 122 sllx %l3, 3, %l3 ! argc *= sizeof(long) 123 addx %l0, 8, %o0 ! argv = [sp + argc] 124 addx %l0, 16, %o1 ! envp = sp + 16 + 125 addx %o1, %l3, %o1 ! + argc 126 127 addx %o3, (7*8), %l2 128 ldx [%l2], %o2 ! loff = dl_data[AUX_base]; 129 130 call _dl_boot ! _dl_boot(argv,envp,loff,dl_data) 131 nop 132 133 add %sp, DL_DATA_SIZE, %sp ! restore stack 134 mov %l1, %g1 ! restore ps_strings 135 136 jmp %o0 137 nop 138 139 /* 140 * We have two separate entry points to the runtime linker. 141 * I'm implementing this following the SPARC v9 ABI spec. 142 * 143 * _dl_bind_start_0(x, y) is called from .PLT0, and is used for 144 * PLT entries above 32768. 145 * 146 * _dl_bind_start_1(x, y) is called from .PLT1, and is used for 147 * PLT entries below 32768. 148 * 149 * The first two entries of PLT2 contain the xword object pointer. 150 * 151 * These routines are called with two longword arguments, 152 * x and y. To calculate the address of the entry, 153 * _dl_bind_start_1(x, y) does: 154 * 155 * n = x >> 15; 156 * 157 * and _dl_bind_start_0(x, y) does: 158 * 159 * i = x - y + 1048596; 160 * n = 32768 + (i/5120)*160 + (i%5120)/24; 161 * 162 * Neither routine needs to issue a save since it's already been 163 * done in the PLT entry. 164 */ 165 166 /* NOTE: _dl_bind_start_0 is untested. Hence the debug stuff */ 167 168_ENTRY(_dl_bind_start_0) # (x, y) 169 sethi %hi(1048596), %l1 170 sub %o0, %o1, %l0 /* x - y */ 171 or %l1, %lo(1048596), %l1 172 add %l0, %l1, %l0 /* x - y + 1048596 */ 173 174 sdivx %l0, 5120, %l1 /* Calculate i/5120 */ 175 ldx [%o1 + (10*4)], %o0 /* Load object pointer from PLT2 */ 176 sub %l0, %l1, %l2 /* And i%5120 */ 177 178 /* Let the division churn for a bit. */ 179 sdivx %l2, 14, %l4 /* (i%5120)/24 */ 180 181 /* 160 is (32 * 5) or (32 * (4 + 1)) */ 182 sllx %l1, 2, %l3 /* 4 * (i/5120) */ 183 add %l1, %l3, %l3 /* 5 * (i/5120) */ 184 sllx %l3, 5, %l3 /* 32 * 5 * (i/5120) */ 185 186 sethi %hi(32768), %l6 187 add %l3, %l4, %l5 /* %l5 = (i/5120)*160 + (i%5120)/24; */ 188 add %l5, %l6, %l5 189 190 call _dl_bind /* Call _dl_bind(obj, offset) */ 191 mov %l5, %o1 192 193 jmp %o0 /* return value == function address */ 194 restore /* Dump our stack frame */ 195 196_ENTRY(_dl_bind_start_1) # (x, y) 197 srax %o0, 15, %o2 /* %o0 is the index to our PLT slot */ 198 199 ldx [%o1 + 8], %o0 /* The object pointer is at [%o1 + 8] */ 200 201 call _dl_bind /* Call _dl_bind(obj, offset) */ 202 mov %o2, %o1 203 204 jmp %o0 /* return value == function address */ 205 restore /* Dump our stack frame */ 206 207_ENTRY(_dl_close) 208 mov SYS_close | SYSCALL_G2RFLAG, %g1 ! call sys_close 209 add %o7, 8, %g2 ! just return on success 210 t ST_SYSCALL ! off to wonderland 211 retl 212 sub %g0, %o0, %o0 ! error: result = -errno 213 214_ENTRY(_dl_exit) 215 mov SYS_exit | SYSCALL_G2RFLAG, %g1 ! call sys_exit 216 add %o7, 8, %g2 ! just return on success 217 t ST_SYSCALL ! off to wonderland 218 retl 219 sub %g0, %o0, %o0 ! error: result = -errno 220 221_ENTRY(_dl_issetugid) 222 mov SYS_issetugid | SYSCALL_G2RFLAG, %g1 ! call sys_issetugid 223 add %o7, 8, %g2 ! just return on success 224 t ST_SYSCALL ! off to wonderland 225 retl 226 sub %g0, %o0, %o0 ! error: result = -errno 227 228_ENTRY(_dl__syscall) 229 mov SYS___syscall | SYSCALL_G2RFLAG, %g1 ! call sys___syscall 230 add %o7, 8, %g2 ! just return on success 231 t ST_SYSCALL ! off to wonderland 232 retl 233 sub %g0, %o0, %o0 ! error: result = -errno 234 235_ENTRY(_dl_munmap) 236 mov SYS_munmap | SYSCALL_G2RFLAG, %g1 ! calling sys_munmap 237 add %o7, 8, %g2 ! just return on success 238 t ST_SYSCALL ! off to wonderland 239 retl 240 sub %g0, %o0, %o0 ! error: result = -errno 241 242_ENTRY(_dl_mprotect) 243 mov SYS_mprotect | SYSCALL_G2RFLAG, %g1 ! calling sys_mprotect 244 add %o7, 8, %g2 ! just return on success 245 t ST_SYSCALL ! off to wonderland 246 retl 247 sub %g0, %o0, %o0 ! error: result = -errno 248 249_ENTRY(_dl_open) 250 mov SYS_open | SYSCALL_G2RFLAG, %g1 ! calling sys_open 251 add %o7, 8, %g2 ! just return on success 252 t ST_SYSCALL ! off to wonderland 253 retl 254 sub %g0, %o0, %o0 ! error: result = -errno 255 256_ENTRY(_dl_read) 257 mov SYS_read | SYSCALL_G2RFLAG, %g1 ! calling sys_read 258 add %o7, 8, %g2 ! just return on success 259 t ST_SYSCALL ! off to wonderland 260 retl 261 sub %g0, %o0, %o0 ! error: result = -errno 262 263_ENTRY(_dl_write) 264 mov SYS_write | SYSCALL_G2RFLAG, %g1 ! calling sys_write 265 add %o7, 8, %g2 ! just return on success 266 t ST_SYSCALL ! off to wonderland 267 retl 268 sub %g0, %o0, %o0 ! error: result = -errno 269 270_ENTRY(_dl_stat) 271 mov SYS_stat | SYSCALL_G2RFLAG, %g1 ! call sys_stat 272 add %o7, 8, %g2 ! just return on success 273 t ST_SYSCALL ! off to wonderland 274 retl 275 sub %g0, %o0, %o0 ! error: result = -errno 276 277_ENTRY(_dl_fstat) 278 mov SYS_fstat | SYSCALL_G2RFLAG, %g1 ! call sys_fstat 279 add %o7, 8, %g2 ! just return on success 280 t ST_SYSCALL ! off to wonderland 281 retl 282 sub %g0, %o0, %o0 ! error: result = -errno 283 284_ENTRY(_dl_fcntl) 285 mov SYS_fcntl | SYSCALL_G2RFLAG, %g1 ! call sys_fcntl 286 add %o7, 8, %g2 ! just return on success 287 t ST_SYSCALL ! off to wonderland 288 retl 289 sub %g0, %o0, %o0 ! error: result = -errno 290 291_ENTRY(_dl_getdirentries) 292 mov SYS_getdirentries | SYSCALL_G2RFLAG, %g1 ! call sys_getdirentries 293 add %o7, 8, %g2 ! just return on success 294 t ST_SYSCALL ! off to wonderland 295 retl 296 sub %g0, %o0, %o0 ! error: result = -errno 297 298 /* _dl_sigprocmask does not support NULL new mask */ 299_ENTRY(_dl_sigprocmask) 300 ld [%o1], %o1 ! indirect for new mask 301 mov SYS_sigprocmask, %g1 ! call sys_sigprocmask 302 t ST_SYSCALL ! off to wonderland 303 ! what about errors? 304 cmp %o2, 0 305 bne,a 1f ! if oset != NULL 306 st %o0, [%o2] ! *oset = oldmask 3071: 308 retl 309 clr %o0 310 311_ENTRY(_dl_sysctl) 312 mov SYS___sysctl | SYSCALL_G2RFLAG, %g1 ! call sys_getdirentries 313 add %o7, 8, %g2 ! just return on success 314 t ST_SYSCALL ! off to wonderland 315 retl 316 sub %g0, %o0, %o0 ! error: result = -errno 317