1*7c478bd9Sstevel@tonic-gate /* 2*7c478bd9Sstevel@tonic-gate * CDDL HEADER START 3*7c478bd9Sstevel@tonic-gate * 4*7c478bd9Sstevel@tonic-gate * The contents of this file are subject to the terms of the 5*7c478bd9Sstevel@tonic-gate * Common Development and Distribution License, Version 1.0 only 6*7c478bd9Sstevel@tonic-gate * (the "License"). You may not use this file except in compliance 7*7c478bd9Sstevel@tonic-gate * with the License. 8*7c478bd9Sstevel@tonic-gate * 9*7c478bd9Sstevel@tonic-gate * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE 10*7c478bd9Sstevel@tonic-gate * or http://www.opensolaris.org/os/licensing. 11*7c478bd9Sstevel@tonic-gate * See the License for the specific language governing permissions 12*7c478bd9Sstevel@tonic-gate * and limitations under the License. 13*7c478bd9Sstevel@tonic-gate * 14*7c478bd9Sstevel@tonic-gate * When distributing Covered Code, include this CDDL HEADER in each 15*7c478bd9Sstevel@tonic-gate * file and include the License file at usr/src/OPENSOLARIS.LICENSE. 16*7c478bd9Sstevel@tonic-gate * If applicable, add the following below this CDDL HEADER, with the 17*7c478bd9Sstevel@tonic-gate * fields enclosed by brackets "[]" replaced with your own identifying 18*7c478bd9Sstevel@tonic-gate * information: Portions Copyright [yyyy] [name of copyright owner] 19*7c478bd9Sstevel@tonic-gate * 20*7c478bd9Sstevel@tonic-gate * CDDL HEADER END 21*7c478bd9Sstevel@tonic-gate */ 22*7c478bd9Sstevel@tonic-gate /* 23*7c478bd9Sstevel@tonic-gate * Copyright 2004 Sun Microsystems, Inc. All rights reserved. 24*7c478bd9Sstevel@tonic-gate * Use is subject to license terms. 25*7c478bd9Sstevel@tonic-gate */ 26*7c478bd9Sstevel@tonic-gate 27*7c478bd9Sstevel@tonic-gate #pragma ident "%Z%%M% %I% %E% SMI" 28*7c478bd9Sstevel@tonic-gate 29*7c478bd9Sstevel@tonic-gate /* 30*7c478bd9Sstevel@tonic-gate * Redirection ld.so. Based on the 4.x binary compatibility ld.so, used 31*7c478bd9Sstevel@tonic-gate * to redirect aliases for ld.so to the real one. 32*7c478bd9Sstevel@tonic-gate */ 33*7c478bd9Sstevel@tonic-gate 34*7c478bd9Sstevel@tonic-gate /* 35*7c478bd9Sstevel@tonic-gate * Import data structures 36*7c478bd9Sstevel@tonic-gate */ 37*7c478bd9Sstevel@tonic-gate #include "synonyms.h" 38*7c478bd9Sstevel@tonic-gate #include <sys/types.h> 39*7c478bd9Sstevel@tonic-gate #include <sys/mman.h> 40*7c478bd9Sstevel@tonic-gate #include <sys/fcntl.h> 41*7c478bd9Sstevel@tonic-gate #include <sys/stat.h> 42*7c478bd9Sstevel@tonic-gate #include <sys/sysconfig.h> 43*7c478bd9Sstevel@tonic-gate #include <sys/auxv.h> 44*7c478bd9Sstevel@tonic-gate #include <elf.h> 45*7c478bd9Sstevel@tonic-gate #include <link.h> 46*7c478bd9Sstevel@tonic-gate #include <string.h> 47*7c478bd9Sstevel@tonic-gate #include "alias_boot.h" 48*7c478bd9Sstevel@tonic-gate 49*7c478bd9Sstevel@tonic-gate /* 50*7c478bd9Sstevel@tonic-gate * Local manifest constants and macros. 51*7c478bd9Sstevel@tonic-gate */ 52*7c478bd9Sstevel@tonic-gate #define ALIGN(x, a) ((uintptr_t)(x) & ~((a) - 1)) 53*7c478bd9Sstevel@tonic-gate #define ROUND(x, a) (((uintptr_t)(x) + ((a) - 1)) & ~((a) - 1)) 54*7c478bd9Sstevel@tonic-gate 55*7c478bd9Sstevel@tonic-gate #define EMPTY strings[EMPTY_S] 56*7c478bd9Sstevel@tonic-gate #define LDSO strings[LDSO_S] 57*7c478bd9Sstevel@tonic-gate #define ZERO strings[ZERO_S] 58*7c478bd9Sstevel@tonic-gate #define CLOSE (*(funcs[CLOSE_F])) 59*7c478bd9Sstevel@tonic-gate #define FSTAT (*(funcs[FSTAT_F])) 60*7c478bd9Sstevel@tonic-gate #define MMAP (*(funcs[MMAP_F])) 61*7c478bd9Sstevel@tonic-gate #define MUNMAP (*(funcs[MUNMAP_F])) 62*7c478bd9Sstevel@tonic-gate #define OPEN (*(funcs[OPEN_F])) 63*7c478bd9Sstevel@tonic-gate #define PANIC (*(funcs[PANIC_F])) 64*7c478bd9Sstevel@tonic-gate #define SYSCONFIG (*(funcs[SYSCONFIG_F])) 65*7c478bd9Sstevel@tonic-gate 66*7c478bd9Sstevel@tonic-gate /* 67*7c478bd9Sstevel@tonic-gate * Alias ld.so entry point -- receives a bootstrap structure and a vector 68*7c478bd9Sstevel@tonic-gate * of strings. The vector is "well-known" to us, and consists of pointers 69*7c478bd9Sstevel@tonic-gate * to string constants. This aliasing bootstrap requires no relocation in 70*7c478bd9Sstevel@tonic-gate * order to run, save for the pointers of constant strings. This second 71*7c478bd9Sstevel@tonic-gate * parameter provides this. Note that this program is carefully coded in 72*7c478bd9Sstevel@tonic-gate * order to maintain the "no bootstrapping" requirement -- it calls only 73*7c478bd9Sstevel@tonic-gate * local functions, uses no intrinsics, etc. 74*7c478bd9Sstevel@tonic-gate */ 75*7c478bd9Sstevel@tonic-gate static void * 76*7c478bd9Sstevel@tonic-gate __rtld(Elf32_Boot *ebp, const char *strings[], int (*funcs[])()) 77*7c478bd9Sstevel@tonic-gate { 78*7c478bd9Sstevel@tonic-gate int i, p; /* working */ 79*7c478bd9Sstevel@tonic-gate long j; /* working */ 80*7c478bd9Sstevel@tonic-gate long page_size = 0; /* size of a page */ 81*7c478bd9Sstevel@tonic-gate const char *program_name = EMPTY; /* our name */ 82*7c478bd9Sstevel@tonic-gate int ldfd; /* fd assigned to ld.so */ 83*7c478bd9Sstevel@tonic-gate int dzfd = 0; /* fd assigned to /dev/zero */ 84*7c478bd9Sstevel@tonic-gate Elf32_Ehdr *ehdr; /* ELF header of ld.so */ 85*7c478bd9Sstevel@tonic-gate Elf32_Phdr *phdr; /* first Phdr in file */ 86*7c478bd9Sstevel@tonic-gate Elf32_Phdr *pptr; /* working Phdr */ 87*7c478bd9Sstevel@tonic-gate Elf32_Phdr *lph = NULL; /* last loadable Phdr */ 88*7c478bd9Sstevel@tonic-gate Elf32_Phdr *fph = NULL; /* first loadable Phdr */ 89*7c478bd9Sstevel@tonic-gate caddr_t maddr; /* pointer to mapping claim */ 90*7c478bd9Sstevel@tonic-gate Elf32_Off mlen; /* total mapping claim */ 91*7c478bd9Sstevel@tonic-gate caddr_t faddr; /* first program mapping of ld.so */ 92*7c478bd9Sstevel@tonic-gate Elf32_Off foff; /* file offset for segment mapping */ 93*7c478bd9Sstevel@tonic-gate Elf32_Off flen; /* file length for segment mapping */ 94*7c478bd9Sstevel@tonic-gate caddr_t addr; /* working mapping address */ 95*7c478bd9Sstevel@tonic-gate caddr_t zaddr; /* /dev/zero working mapping addr */ 96*7c478bd9Sstevel@tonic-gate struct stat sb; /* stat buffer for sizing */ 97*7c478bd9Sstevel@tonic-gate auxv_t *ap; /* working aux pointer */ 98*7c478bd9Sstevel@tonic-gate 99*7c478bd9Sstevel@tonic-gate /* 100*7c478bd9Sstevel@tonic-gate * Discover things about our environment: auxiliary vector (if 101*7c478bd9Sstevel@tonic-gate * any), arguments, program name, and the like. 102*7c478bd9Sstevel@tonic-gate */ 103*7c478bd9Sstevel@tonic-gate while (ebp->eb_tag != NULL) { 104*7c478bd9Sstevel@tonic-gate switch (ebp->eb_tag) { 105*7c478bd9Sstevel@tonic-gate case EB_ARGV: 106*7c478bd9Sstevel@tonic-gate program_name = *((char **)ebp->eb_un.eb_ptr); 107*7c478bd9Sstevel@tonic-gate break; 108*7c478bd9Sstevel@tonic-gate case EB_AUXV: 109*7c478bd9Sstevel@tonic-gate for (ap = (auxv_t *)ebp->eb_un.eb_ptr; 110*7c478bd9Sstevel@tonic-gate ap->a_type != AT_NULL; ap++) 111*7c478bd9Sstevel@tonic-gate if (ap->a_type == AT_PAGESZ) { 112*7c478bd9Sstevel@tonic-gate page_size = ap->a_un.a_val; 113*7c478bd9Sstevel@tonic-gate break; 114*7c478bd9Sstevel@tonic-gate } 115*7c478bd9Sstevel@tonic-gate break; 116*7c478bd9Sstevel@tonic-gate } 117*7c478bd9Sstevel@tonic-gate ebp++; 118*7c478bd9Sstevel@tonic-gate } 119*7c478bd9Sstevel@tonic-gate 120*7c478bd9Sstevel@tonic-gate /* 121*7c478bd9Sstevel@tonic-gate * If we didn't get a page size from looking in the auxiliary 122*7c478bd9Sstevel@tonic-gate * vector, we need to get one now. 123*7c478bd9Sstevel@tonic-gate */ 124*7c478bd9Sstevel@tonic-gate if (page_size == 0) { 125*7c478bd9Sstevel@tonic-gate page_size = SYSCONFIG(_CONFIG_PAGESIZE); 126*7c478bd9Sstevel@tonic-gate ebp->eb_tag = EB_PAGESIZE, (ebp++)->eb_un.eb_val = 127*7c478bd9Sstevel@tonic-gate (Elf32_Word)page_size; 128*7c478bd9Sstevel@tonic-gate } 129*7c478bd9Sstevel@tonic-gate 130*7c478bd9Sstevel@tonic-gate /* 131*7c478bd9Sstevel@tonic-gate * Map in the real ld.so. Note that we're mapping it as 132*7c478bd9Sstevel@tonic-gate * an ELF database, not as a program -- we just want to walk it's 133*7c478bd9Sstevel@tonic-gate * data structures. Further mappings will actually establish the 134*7c478bd9Sstevel@tonic-gate * program in the address space. 135*7c478bd9Sstevel@tonic-gate */ 136*7c478bd9Sstevel@tonic-gate if ((ldfd = OPEN(LDSO, O_RDONLY)) == -1) 137*7c478bd9Sstevel@tonic-gate PANIC(program_name); 138*7c478bd9Sstevel@tonic-gate if (FSTAT(ldfd, &sb) == -1) 139*7c478bd9Sstevel@tonic-gate PANIC(program_name); 140*7c478bd9Sstevel@tonic-gate ehdr = (Elf32_Ehdr *)MMAP(0, sb.st_size, PROT_READ | PROT_EXEC, 141*7c478bd9Sstevel@tonic-gate MAP_SHARED, ldfd, 0); 142*7c478bd9Sstevel@tonic-gate if (ehdr == (Elf32_Ehdr *)-1) 143*7c478bd9Sstevel@tonic-gate PANIC(program_name); 144*7c478bd9Sstevel@tonic-gate 145*7c478bd9Sstevel@tonic-gate /* 146*7c478bd9Sstevel@tonic-gate * Validate the file we're looking at, ensure it has the correct 147*7c478bd9Sstevel@tonic-gate * ELF structures, such as: ELF magic numbers, coded for SPARC, 148*7c478bd9Sstevel@tonic-gate * is a ".so", etc. 149*7c478bd9Sstevel@tonic-gate */ 150*7c478bd9Sstevel@tonic-gate if (ehdr->e_ident[EI_MAG0] != ELFMAG0 || 151*7c478bd9Sstevel@tonic-gate ehdr->e_ident[EI_MAG1] != ELFMAG1 || 152*7c478bd9Sstevel@tonic-gate ehdr->e_ident[EI_MAG2] != ELFMAG2 || 153*7c478bd9Sstevel@tonic-gate ehdr->e_ident[EI_MAG3] != ELFMAG3) 154*7c478bd9Sstevel@tonic-gate PANIC(program_name); 155*7c478bd9Sstevel@tonic-gate if (ehdr->e_ident[EI_CLASS] != ELFCLASS32 || 156*7c478bd9Sstevel@tonic-gate ehdr->e_ident[EI_DATA] != ELFDATA2MSB) 157*7c478bd9Sstevel@tonic-gate PANIC(program_name); 158*7c478bd9Sstevel@tonic-gate if (ehdr->e_type != ET_DYN) 159*7c478bd9Sstevel@tonic-gate PANIC(program_name); 160*7c478bd9Sstevel@tonic-gate if ((ehdr->e_machine != EM_SPARC) && 161*7c478bd9Sstevel@tonic-gate (ehdr->e_machine != EM_SPARC32PLUS)) 162*7c478bd9Sstevel@tonic-gate PANIC(program_name); 163*7c478bd9Sstevel@tonic-gate if (ehdr->e_version > EV_CURRENT) 164*7c478bd9Sstevel@tonic-gate PANIC(program_name); 165*7c478bd9Sstevel@tonic-gate 166*7c478bd9Sstevel@tonic-gate /* 167*7c478bd9Sstevel@tonic-gate * Point at program headers and start figuring out what to load. 168*7c478bd9Sstevel@tonic-gate */ 169*7c478bd9Sstevel@tonic-gate phdr = (Elf32_Phdr *)((caddr_t)ehdr + ehdr->e_phoff); 170*7c478bd9Sstevel@tonic-gate for (p = 0, pptr = phdr; p < (int)ehdr->e_phnum; p++, 171*7c478bd9Sstevel@tonic-gate pptr = (Elf32_Phdr *)((caddr_t)pptr + ehdr->e_phentsize)) 172*7c478bd9Sstevel@tonic-gate if (pptr->p_type == PT_LOAD) { 173*7c478bd9Sstevel@tonic-gate if (fph == 0) { 174*7c478bd9Sstevel@tonic-gate fph = pptr; 175*7c478bd9Sstevel@tonic-gate } else if (pptr->p_vaddr <= lph->p_vaddr) 176*7c478bd9Sstevel@tonic-gate PANIC(program_name); 177*7c478bd9Sstevel@tonic-gate lph = pptr; 178*7c478bd9Sstevel@tonic-gate } 179*7c478bd9Sstevel@tonic-gate 180*7c478bd9Sstevel@tonic-gate /* 181*7c478bd9Sstevel@tonic-gate * We'd better have at least one loadable segment. 182*7c478bd9Sstevel@tonic-gate */ 183*7c478bd9Sstevel@tonic-gate if (fph == 0) 184*7c478bd9Sstevel@tonic-gate PANIC(program_name); 185*7c478bd9Sstevel@tonic-gate 186*7c478bd9Sstevel@tonic-gate /* 187*7c478bd9Sstevel@tonic-gate * Map enough address space to hold the program (as opposed to the 188*7c478bd9Sstevel@tonic-gate * file) represented by ld.so. The amount to be assigned is the 189*7c478bd9Sstevel@tonic-gate * range between the end of the last loadable segment and the 190*7c478bd9Sstevel@tonic-gate * beginning of the first PLUS the alignment of the first segment. 191*7c478bd9Sstevel@tonic-gate * mmap() can assign us any page-aligned address, but the relocations 192*7c478bd9Sstevel@tonic-gate * assume the alignments included in the program header. As an 193*7c478bd9Sstevel@tonic-gate * optimization, however, let's assume that mmap() will actually 194*7c478bd9Sstevel@tonic-gate * give us an aligned address -- since if it does, we can save 195*7c478bd9Sstevel@tonic-gate * an munmap() later on. If it doesn't -- then go try it again. 196*7c478bd9Sstevel@tonic-gate */ 197*7c478bd9Sstevel@tonic-gate mlen = ROUND((lph->p_vaddr + lph->p_memsz) - 198*7c478bd9Sstevel@tonic-gate ALIGN(fph->p_vaddr, page_size), page_size); 199*7c478bd9Sstevel@tonic-gate maddr = (caddr_t)MMAP(0, mlen, PROT_READ | PROT_EXEC, 200*7c478bd9Sstevel@tonic-gate MAP_SHARED, ldfd, 0); 201*7c478bd9Sstevel@tonic-gate if (maddr == (caddr_t)-1) 202*7c478bd9Sstevel@tonic-gate PANIC(program_name); 203*7c478bd9Sstevel@tonic-gate faddr = (caddr_t)ROUND(maddr, fph->p_align); 204*7c478bd9Sstevel@tonic-gate 205*7c478bd9Sstevel@tonic-gate /* 206*7c478bd9Sstevel@tonic-gate * Check to see whether alignment skew was really needed. 207*7c478bd9Sstevel@tonic-gate */ 208*7c478bd9Sstevel@tonic-gate if (faddr != maddr) { 209*7c478bd9Sstevel@tonic-gate (void) MUNMAP(maddr, mlen); 210*7c478bd9Sstevel@tonic-gate mlen = ROUND((lph->p_vaddr + lph->p_memsz) - 211*7c478bd9Sstevel@tonic-gate ALIGN(fph->p_vaddr, fph->p_align) + fph->p_align, 212*7c478bd9Sstevel@tonic-gate page_size); 213*7c478bd9Sstevel@tonic-gate maddr = (caddr_t)MMAP(0, mlen, PROT_READ | PROT_EXEC, 214*7c478bd9Sstevel@tonic-gate MAP_SHARED, ldfd, 0); 215*7c478bd9Sstevel@tonic-gate if (maddr == (caddr_t)-1) 216*7c478bd9Sstevel@tonic-gate PANIC(program_name); 217*7c478bd9Sstevel@tonic-gate faddr = (caddr_t)ROUND(maddr, fph->p_align); 218*7c478bd9Sstevel@tonic-gate } 219*7c478bd9Sstevel@tonic-gate 220*7c478bd9Sstevel@tonic-gate /* 221*7c478bd9Sstevel@tonic-gate * We have the address space reserved, so map each loadable segment. 222*7c478bd9Sstevel@tonic-gate */ 223*7c478bd9Sstevel@tonic-gate for (p = 0, pptr = phdr; p < (int)ehdr->e_phnum; p++, 224*7c478bd9Sstevel@tonic-gate pptr = (Elf32_Phdr *)((caddr_t)pptr + ehdr->e_phentsize)) { 225*7c478bd9Sstevel@tonic-gate 226*7c478bd9Sstevel@tonic-gate /* 227*7c478bd9Sstevel@tonic-gate * Skip non-loadable segments or segments that don't occupy 228*7c478bd9Sstevel@tonic-gate * any memory. 229*7c478bd9Sstevel@tonic-gate */ 230*7c478bd9Sstevel@tonic-gate if ((pptr->p_type != PT_LOAD) || (pptr->p_memsz == 0)) 231*7c478bd9Sstevel@tonic-gate continue; 232*7c478bd9Sstevel@tonic-gate 233*7c478bd9Sstevel@tonic-gate /* 234*7c478bd9Sstevel@tonic-gate * Determine the file offset to which the mapping will 235*7c478bd9Sstevel@tonic-gate * directed (must be aligned) and how much to map (might 236*7c478bd9Sstevel@tonic-gate * be more than the file in the case of .bss.) 237*7c478bd9Sstevel@tonic-gate */ 238*7c478bd9Sstevel@tonic-gate foff = ALIGN(pptr->p_offset, page_size); 239*7c478bd9Sstevel@tonic-gate flen = pptr->p_memsz + (pptr->p_offset - foff); 240*7c478bd9Sstevel@tonic-gate 241*7c478bd9Sstevel@tonic-gate /* 242*7c478bd9Sstevel@tonic-gate * Set address of this segment relative to our base. 243*7c478bd9Sstevel@tonic-gate */ 244*7c478bd9Sstevel@tonic-gate addr = (caddr_t)ALIGN(faddr + pptr->p_vaddr, page_size); 245*7c478bd9Sstevel@tonic-gate 246*7c478bd9Sstevel@tonic-gate /* 247*7c478bd9Sstevel@tonic-gate * If this is the first program header, record our base 248*7c478bd9Sstevel@tonic-gate * address for later use. 249*7c478bd9Sstevel@tonic-gate */ 250*7c478bd9Sstevel@tonic-gate if (pptr == phdr) { 251*7c478bd9Sstevel@tonic-gate ebp->eb_tag = EB_LDSO_BASE; 252*7c478bd9Sstevel@tonic-gate (ebp++)->eb_un.eb_ptr = (Elf32_Addr)addr; 253*7c478bd9Sstevel@tonic-gate } 254*7c478bd9Sstevel@tonic-gate 255*7c478bd9Sstevel@tonic-gate /* 256*7c478bd9Sstevel@tonic-gate * Unmap anything from the last mapping address to this 257*7c478bd9Sstevel@tonic-gate * one. 258*7c478bd9Sstevel@tonic-gate */ 259*7c478bd9Sstevel@tonic-gate if (addr - maddr) { 260*7c478bd9Sstevel@tonic-gate (void) MUNMAP(maddr, addr - maddr); 261*7c478bd9Sstevel@tonic-gate mlen -= addr - maddr; 262*7c478bd9Sstevel@tonic-gate } 263*7c478bd9Sstevel@tonic-gate 264*7c478bd9Sstevel@tonic-gate /* 265*7c478bd9Sstevel@tonic-gate * Determine the mapping protection from the section 266*7c478bd9Sstevel@tonic-gate * attributes. 267*7c478bd9Sstevel@tonic-gate */ 268*7c478bd9Sstevel@tonic-gate i = 0; 269*7c478bd9Sstevel@tonic-gate if (pptr->p_flags & PF_R) 270*7c478bd9Sstevel@tonic-gate i |= PROT_READ; 271*7c478bd9Sstevel@tonic-gate if (pptr->p_flags & PF_W) 272*7c478bd9Sstevel@tonic-gate i |= PROT_WRITE; 273*7c478bd9Sstevel@tonic-gate if (pptr->p_flags & PF_X) 274*7c478bd9Sstevel@tonic-gate i |= PROT_EXEC; 275*7c478bd9Sstevel@tonic-gate if ((caddr_t)MMAP((caddr_t)addr, flen, i, 276*7c478bd9Sstevel@tonic-gate MAP_FIXED | MAP_PRIVATE, ldfd, foff) == (caddr_t)-1) 277*7c478bd9Sstevel@tonic-gate PANIC(program_name); 278*7c478bd9Sstevel@tonic-gate 279*7c478bd9Sstevel@tonic-gate /* 280*7c478bd9Sstevel@tonic-gate * If the memory occupancy of the segment overflows the 281*7c478bd9Sstevel@tonic-gate * definition in the file, we need to "zero out" the 282*7c478bd9Sstevel@tonic-gate * end of the mapping we've established, and if necessary, 283*7c478bd9Sstevel@tonic-gate * map some more space from /dev/zero. 284*7c478bd9Sstevel@tonic-gate */ 285*7c478bd9Sstevel@tonic-gate if (pptr->p_memsz > pptr->p_filesz) { 286*7c478bd9Sstevel@tonic-gate foff = (uintptr_t)faddr + pptr->p_vaddr + 287*7c478bd9Sstevel@tonic-gate pptr->p_filesz; 288*7c478bd9Sstevel@tonic-gate zaddr = (caddr_t)ROUND(foff, page_size); 289*7c478bd9Sstevel@tonic-gate for (j = 0; j < (int)(zaddr - foff); j++) 290*7c478bd9Sstevel@tonic-gate *((char *)foff + j) = 0; 291*7c478bd9Sstevel@tonic-gate j = (faddr + pptr->p_vaddr + pptr->p_memsz) - zaddr; 292*7c478bd9Sstevel@tonic-gate if (j > 0) { 293*7c478bd9Sstevel@tonic-gate if (dzfd == 0) { 294*7c478bd9Sstevel@tonic-gate dzfd = OPEN(ZERO, O_RDWR); 295*7c478bd9Sstevel@tonic-gate if (dzfd == -1) 296*7c478bd9Sstevel@tonic-gate PANIC(program_name); 297*7c478bd9Sstevel@tonic-gate } 298*7c478bd9Sstevel@tonic-gate if ((caddr_t)MMAP((caddr_t)zaddr, j, i, 299*7c478bd9Sstevel@tonic-gate MAP_FIXED | MAP_PRIVATE, dzfd, 300*7c478bd9Sstevel@tonic-gate 0) == (caddr_t)-1) 301*7c478bd9Sstevel@tonic-gate PANIC(program_name); 302*7c478bd9Sstevel@tonic-gate } 303*7c478bd9Sstevel@tonic-gate } 304*7c478bd9Sstevel@tonic-gate 305*7c478bd9Sstevel@tonic-gate /* 306*7c478bd9Sstevel@tonic-gate * Update the mapping claim pointer. 307*7c478bd9Sstevel@tonic-gate */ 308*7c478bd9Sstevel@tonic-gate maddr = addr + ROUND(flen, page_size); 309*7c478bd9Sstevel@tonic-gate mlen -= maddr - addr; 310*7c478bd9Sstevel@tonic-gate } 311*7c478bd9Sstevel@tonic-gate 312*7c478bd9Sstevel@tonic-gate /* 313*7c478bd9Sstevel@tonic-gate * Unmap any final reservation. 314*7c478bd9Sstevel@tonic-gate */ 315*7c478bd9Sstevel@tonic-gate if (mlen != 0) 316*7c478bd9Sstevel@tonic-gate (void) MUNMAP(maddr, mlen); 317*7c478bd9Sstevel@tonic-gate 318*7c478bd9Sstevel@tonic-gate /* 319*7c478bd9Sstevel@tonic-gate * Clean up file descriptor space we've consumed. Pass along 320*7c478bd9Sstevel@tonic-gate * the /dev/zero file descriptor we got -- every cycle counts. 321*7c478bd9Sstevel@tonic-gate */ 322*7c478bd9Sstevel@tonic-gate (void) CLOSE(ldfd); 323*7c478bd9Sstevel@tonic-gate if (dzfd != 0) 324*7c478bd9Sstevel@tonic-gate ebp->eb_tag = EB_DEVZERO, (ebp++)->eb_un.eb_val = dzfd; 325*7c478bd9Sstevel@tonic-gate 326*7c478bd9Sstevel@tonic-gate /* 327*7c478bd9Sstevel@tonic-gate * The call itself. Note that we start 1 instruction word in. 328*7c478bd9Sstevel@tonic-gate * The ELF ld.so contains an "entry vector" of branch instructions, 329*7c478bd9Sstevel@tonic-gate * which, for our interest are: 330*7c478bd9Sstevel@tonic-gate * +0: ba, a <normal startup> 331*7c478bd9Sstevel@tonic-gate * +4: ba, a <compatibility startup> 332*7c478bd9Sstevel@tonic-gate * +8: ba, a <alias startup> 333*7c478bd9Sstevel@tonic-gate * By starting at the alias startup, the ELF ld.so knows 334*7c478bd9Sstevel@tonic-gate * that a pointer to "eb" is available to it and further knows 335*7c478bd9Sstevel@tonic-gate * how to calculate the offset to the program's arguments and 336*7c478bd9Sstevel@tonic-gate * other structures. We do the "call" by returning to our 337*7c478bd9Sstevel@tonic-gate * bootstrap and then jumping to the address that we return. 338*7c478bd9Sstevel@tonic-gate */ 339*7c478bd9Sstevel@tonic-gate ebp->eb_tag = EB_NULL, ebp->eb_un.eb_val = 0; 340*7c478bd9Sstevel@tonic-gate return ((void *)(ehdr->e_entry + faddr + 8)); 341*7c478bd9Sstevel@tonic-gate } 342