+++ /dev/null
-/* $NetBSD: map_object.c,v 1.53 2014/10/30 07:53:41 martin Exp $ */
-
-/*
- * Copyright 1996 John D. Polstra.
- * Copyright 1996 Matt Thomas <matt@3am-software.com>
- * Copyright 2002 Charles M. Hannum <root@ihack.net>
- * All rights reserved.
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions
- * are met:
- * 1. Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- * 2. Redistributions in binary form must reproduce the above copyright
- * notice, this list of conditions and the following disclaimer in the
- * documentation and/or other materials provided with the distribution.
- * 3. All advertising materials mentioning features or use of this software
- * must display the following acknowledgement:
- * This product includes software developed by John Polstra.
- * 4. The name of the author may not be used to endorse or promote products
- * derived from this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
- * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
- * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
- * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
- * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
- * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
- * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-
-#include <sys/cdefs.h>
-#ifndef lint
-__RCSID("$NetBSD: map_object.c,v 1.53 2014/10/30 07:53:41 martin Exp $");
-#endif /* not lint */
-
-#include <errno.h>
-#include <stddef.h>
-#include <stdlib.h>
-#include <string.h>
-#include <unistd.h>
-#include <sys/stat.h>
-#include <sys/types.h>
-#include <sys/mman.h>
-
-#include "debug.h"
-#include "rtld.h"
-
-#if defined(__minix)
-#define MINIXVERBOSE 0
-
-#if MINIXVERBOSE
-#include <stdio.h>
-#endif
-
-static void Pread(void *addr, size_t size, int fd, off_t off)
-{
- int s;
- if((s=pread(fd,addr, size, off)) < 0) {
- _rtld_error("pread failed");
- exit(1);
- }
-
-#if MINIXVERBOSE
- fprintf(stderr, "read 0x%lx bytes from offset 0x%lx to addr 0x%lx\n", size, off, addr);
-#endif
-}
-
-/* minix-without-mmap version of _rtld_map_object() */
-
-#else
-static int protflags(int); /* Elf flags -> mmap protection */
-#endif /* defined(__minix) */
-
-#define EA_UNDEF (~(Elf_Addr)0)
-
-/*
- * Map a shared object into memory. The argument is a file descriptor,
- * which must be open on the object and positioned at its beginning.
- *
- * The return value is a pointer to a newly-allocated Obj_Entry structure
- * for the shared object. Returns NULL on failure.
- */
-Obj_Entry *
-_rtld_map_object_fallback(const char *path, int fd, const struct stat *sb)
-{
- Obj_Entry *obj;
- Elf_Ehdr *ehdr;
- Elf_Phdr *phdr;
-#if defined(__HAVE_TLS_VARIANT_I) || defined(__HAVE_TLS_VARIANT_II)
- Elf_Phdr *phtls;
-#endif
- size_t phsize;
- Elf_Phdr *phlimit;
- Elf_Phdr *segs[2];
- int nsegs;
- caddr_t mapbase = MAP_FAILED;
- size_t mapsize = 0;
-#if !defined(__minix)
- int mapflags;
-#endif /* !defined(__minix) */
- Elf_Off base_offset;
-#if !defined(__minix)
-#ifdef MAP_ALIGNED
- Elf_Addr base_alignment;
-#endif
-#endif /* !defined(__minix) */
- Elf_Addr base_vaddr;
- Elf_Addr base_vlimit;
- Elf_Addr text_vlimit;
-#if !defined(__minix)
- int text_flags;
-#endif /* !defined(__minix) */
- caddr_t base_addr;
- Elf_Off data_offset;
- Elf_Addr data_vaddr;
- Elf_Addr data_vlimit;
-#if !defined(__minix)
- int data_flags;
-#endif /* !defined(__minix) */
- caddr_t data_addr;
-#if defined(__HAVE_TLS_VARIANT_I) || defined(__HAVE_TLS_VARIANT_II)
- Elf_Addr tls_vaddr = 0; /* Noise GCC */
-#endif
- Elf_Addr phdr_vaddr;
- size_t phdr_memsz;
-#if defined(__minix) && (defined(__HAVE_TLS_VARIANT_I) || defined(__HAVE_TLS_VARIANT_II))
- caddr_t gap_addr;
- size_t gap_size;
-#endif /* defined(__minix) */
- int i;
-#ifdef RTLD_LOADER
- Elf_Addr clear_vaddr;
- caddr_t clear_addr;
- size_t nclear;
-#endif
-
- if (sb != NULL && sb->st_size < (off_t)sizeof (Elf_Ehdr)) {
- _rtld_error("%s: not ELF file (too short)", path);
- return NULL;
- }
-
- obj = _rtld_obj_new();
- obj->path = xstrdup(path);
- obj->pathlen = strlen(path);
- if (sb != NULL) {
- obj->dev = sb->st_dev;
- obj->ino = sb->st_ino;
- }
-
-#ifdef __minix
- ehdr = mmap(NULL, _rtld_pagesz, PROT_READ|PROT_WRITE,
- MAP_PREALLOC|MAP_ANON, -1, (off_t)0);
- Pread(ehdr, _rtld_pagesz, fd, 0);
-#if MINIXVERBOSE
- fprintf(stderr, "minix mmap for header: 0x%lx\n", ehdr);
-#endif
-#else
- ehdr = mmap(NULL, _rtld_pagesz, PROT_READ, MAP_FILE | MAP_SHARED, fd,
- (off_t)0);
-#endif
- obj->ehdr = ehdr;
- if (ehdr == MAP_FAILED) {
- _rtld_error("%s: read error: %s", path, xstrerror(errno));
- goto bad;
- }
- /* Make sure the file is valid */
- if (memcmp(ELFMAG, ehdr->e_ident, SELFMAG) != 0) {
- _rtld_error("%s: not ELF file (magic number bad)", path);
- goto bad;
- }
- if (ehdr->e_ident[EI_CLASS] != ELFCLASS) {
- _rtld_error("%s: invalid ELF class %x; expected %x", path,
- ehdr->e_ident[EI_CLASS], ELFCLASS);
- goto bad;
- }
- /* Elf_e_ident includes class */
- if (ehdr->e_ident[EI_VERSION] != EV_CURRENT ||
- ehdr->e_version != EV_CURRENT ||
- ehdr->e_ident[EI_DATA] != ELFDEFNNAME(MACHDEP_ENDIANNESS)) {
- _rtld_error("%s: unsupported file version", path);
- goto bad;
- }
- if (ehdr->e_type != ET_EXEC && ehdr->e_type != ET_DYN) {
- _rtld_error("%s: unsupported file type", path);
- goto bad;
- }
- switch (ehdr->e_machine) {
- ELFDEFNNAME(MACHDEP_ID_CASES)
- default:
- _rtld_error("%s: unsupported machine", path);
- goto bad;
- }
-
- /*
- * We rely on the program header being in the first page. This is
- * not strictly required by the ABI specification, but it seems to
- * always true in practice. And, it simplifies things considerably.
- */
- assert(ehdr->e_phentsize == sizeof(Elf_Phdr));
- assert(ehdr->e_phoff + ehdr->e_phnum * sizeof(Elf_Phdr) <=
- _rtld_pagesz);
-
- /*
- * Scan the program header entries, and save key information.
- *
- * We rely on there being exactly two load segments, text and data,
- * in that order.
- */
- phdr = (Elf_Phdr *) ((caddr_t)ehdr + ehdr->e_phoff);
-#if defined(__HAVE_TLS_VARIANT_I) || defined(__HAVE_TLS_VARIANT_II)
- phtls = NULL;
-#endif
- phsize = ehdr->e_phnum * sizeof(phdr[0]);
- obj->phdr = NULL;
- phdr_vaddr = EA_UNDEF;
- phdr_memsz = 0;
- phlimit = phdr + ehdr->e_phnum;
- nsegs = 0;
- while (phdr < phlimit) {
- switch (phdr->p_type) {
- case PT_INTERP:
- obj->interp = (void *)(uintptr_t)phdr->p_vaddr;
- dbg(("%s: PT_INTERP %p", obj->path, obj->interp));
- break;
-
- case PT_LOAD:
- if (nsegs < 2)
- segs[nsegs] = phdr;
- ++nsegs;
-
- dbg(("%s: %s %p phsize %" PRImemsz, obj->path, "PT_LOAD",
- (void *)(uintptr_t)phdr->p_vaddr, phdr->p_memsz));
- break;
-
- case PT_PHDR:
- phdr_vaddr = phdr->p_vaddr;
- phdr_memsz = phdr->p_memsz;
- dbg(("%s: %s %p phsize %" PRImemsz, obj->path, "PT_PHDR",
- (void *)(uintptr_t)phdr->p_vaddr, phdr->p_memsz));
- break;
-
- case PT_DYNAMIC:
- obj->dynamic = (void *)(uintptr_t)phdr->p_vaddr;
- dbg(("%s: %s %p phsize %" PRImemsz, obj->path, "PT_DYNAMIC",
- (void *)(uintptr_t)phdr->p_vaddr, phdr->p_memsz));
- break;
-
-#if defined(__HAVE_TLS_VARIANT_I) || defined(__HAVE_TLS_VARIANT_II)
- case PT_TLS:
- phtls = phdr;
- dbg(("%s: %s %p phsize %" PRImemsz, obj->path, "PT_TLS",
- (void *)(uintptr_t)phdr->p_vaddr, phdr->p_memsz));
- break;
-#endif
-#ifdef __ARM_EABI__
- case PT_ARM_EXIDX:
- obj->exidx_start = (void *)(uintptr_t)phdr->p_vaddr;
- obj->exidx_sz = phdr->p_memsz;
- break;
-#endif
- }
-
- ++phdr;
- }
- phdr = (Elf_Phdr *) ((caddr_t)ehdr + ehdr->e_phoff);
- obj->entry = (void *)(uintptr_t)ehdr->e_entry;
- if (!obj->dynamic) {
- _rtld_error("%s: not dynamically linked", path);
- goto bad;
- }
- if (nsegs != 2) {
- _rtld_error("%s: wrong number of segments (%d != 2)", path,
- nsegs);
- goto bad;
- }
-
- /*
- * Map the entire address space of the object as a file
- * region to stake out our contiguous region and establish a
- * base for relocation. We use a file mapping so that
- * the kernel will give us whatever alignment is appropriate
- * for the platform we're running on.
- *
- * We map it using the text protection, map the data segment
- * into the right place, then map an anon segment for the bss
- * and unmap the gaps left by padding to alignment.
- */
-
-#if !defined(__minix)
-#ifdef MAP_ALIGNED
- base_alignment = segs[0]->p_align;
-#endif
-#endif /* !defined(__minix) */
- base_offset = round_down(segs[0]->p_offset);
- base_vaddr = round_down(segs[0]->p_vaddr);
- base_vlimit = round_up(segs[1]->p_vaddr + segs[1]->p_memsz);
- text_vlimit = round_up(segs[0]->p_vaddr + segs[0]->p_memsz);
-#if !defined(__minix)
- text_flags = protflags(segs[0]->p_flags);
-#endif /* !defined(__minix) */
- data_offset = round_down(segs[1]->p_offset);
- data_vaddr = round_down(segs[1]->p_vaddr);
- data_vlimit = round_up(segs[1]->p_vaddr + segs[1]->p_filesz);
-#if !defined(__minix)
- data_flags = protflags(segs[1]->p_flags);
-#endif /* !defined(__minix) */
-#ifdef RTLD_LOADER
- clear_vaddr = segs[1]->p_vaddr + segs[1]->p_filesz;
-#endif
-
- obj->textsize = text_vlimit - base_vaddr;
- obj->vaddrbase = base_vaddr;
- obj->isdynamic = ehdr->e_type == ET_DYN;
-
-#if defined(__HAVE_TLS_VARIANT_I) || defined(__HAVE_TLS_VARIANT_II)
- if (phtls != NULL) {
- ++_rtld_tls_dtv_generation;
- obj->tlsindex = ++_rtld_tls_max_index;
- obj->tlssize = phtls->p_memsz;
- obj->tlsalign = phtls->p_align;
- obj->tlsinitsize = phtls->p_filesz;
- tls_vaddr = phtls->p_vaddr;
- }
-#endif
-
- obj->phdr_loaded = false;
- for (i = 0; i < nsegs; i++) {
- if (phdr_vaddr != EA_UNDEF &&
- segs[i]->p_vaddr <= phdr_vaddr &&
- segs[i]->p_memsz >= phdr_memsz) {
- obj->phdr_loaded = true;
- break;
- }
- if (segs[i]->p_offset <= ehdr->e_phoff &&
- segs[i]->p_memsz >= phsize) {
- phdr_vaddr = segs[i]->p_vaddr + ehdr->e_phoff;
- phdr_memsz = phsize;
- obj->phdr_loaded = true;
- break;
- }
- }
- if (obj->phdr_loaded) {
- obj->phdr = (void *)(uintptr_t)phdr_vaddr;
- obj->phsize = phdr_memsz;
- } else {
- Elf_Phdr *buf;
- buf = xmalloc(phsize);
- if (buf == NULL) {
- _rtld_error("%s: cannot allocate program header", path);
- goto bad;
- }
- memcpy(buf, phdr, phsize);
- obj->phdr = buf;
- obj->phsize = phsize;
- }
- dbg(("%s: phdr %p phsize %zu (%s)", obj->path, obj->phdr, obj->phsize,
- obj->phdr_loaded ? "loaded" : "allocated"));
-
- /* Unmap header if it overlaps the first load section. */
- if (base_offset < _rtld_pagesz) {
- munmap(ehdr, _rtld_pagesz);
- obj->ehdr = MAP_FAILED;
- }
-
- /*
- * Calculate log2 of the base section alignment.
- */
-#if !defined(__minix)
- mapflags = 0;
-#ifdef MAP_ALIGNED
- if (base_alignment > _rtld_pagesz) {
- unsigned int log2 = 0;
- for (; base_alignment > 1; base_alignment >>= 1)
- log2++;
- mapflags = MAP_ALIGNED(log2);
- }
-#endif
-#endif /* defined(__minix) */
-
-#ifdef RTLD_LOADER
- base_addr = obj->isdynamic ? NULL : (caddr_t)base_vaddr;
-#else
- base_addr = NULL;
-#endif
- mapsize = base_vlimit - base_vaddr;
-
-#ifndef __minix
- mapbase = mmap(base_addr, mapsize, text_flags,
- mapflags | MAP_FILE | MAP_PRIVATE, fd, base_offset);
-#else
- mapbase = mmap(base_addr, mapsize, PROT_READ|PROT_WRITE,
- MAP_ANON | MAP_PREALLOC, -1, 0);
-#if MINIXVERBOSE
- fprintf(stderr, "minix mmap for whole block: 0x%lx-0x%lx\n", mapbase, mapbase+mapsize);
-#endif
- Pread(mapbase, obj->textsize, fd, 0);
-#endif
- if (mapbase == MAP_FAILED) {
- _rtld_error("mmap of entire address space failed: %s",
- xstrerror(errno));
- goto bad;
- }
-
- /* Overlay the data segment onto the proper region. */
- data_addr = mapbase + (data_vaddr - base_vaddr);
-#ifdef __minix
- Pread(data_addr, data_vlimit - data_vaddr, fd, data_offset);
-#else
- if (mmap(data_addr, data_vlimit - data_vaddr, data_flags,
- MAP_FILE | MAP_PRIVATE | MAP_FIXED, fd, data_offset) ==
- MAP_FAILED) {
- _rtld_error("mmap of data failed: %s", xstrerror(errno));
- goto bad;
- }
-
- /* Overlay the bss segment onto the proper region. */
- if (mmap(mapbase + data_vlimit - base_vaddr, base_vlimit - data_vlimit,
- data_flags, MAP_ANON | MAP_PRIVATE | MAP_FIXED, -1, 0) ==
- MAP_FAILED) {
- _rtld_error("mmap of bss failed: %s", xstrerror(errno));
- goto bad;
- }
-
- /* Unmap the gap between the text and data. */
- gap_addr = mapbase + round_up(text_vlimit - base_vaddr);
- gap_size = data_addr - gap_addr;
- if (gap_size != 0 && mprotect(gap_addr, gap_size, PROT_NONE) == -1) {
- _rtld_error("mprotect of text -> data gap failed: %s",
- xstrerror(errno));
- goto bad;
- }
-#endif /* defined(__minix) */
-
-#ifdef RTLD_LOADER
- /* Clear any BSS in the last page of the data segment. */
- clear_addr = mapbase + (clear_vaddr - base_vaddr);
- if ((nclear = data_vlimit - clear_vaddr) > 0)
- memset(clear_addr, 0, nclear);
-
- /* Non-file portion of BSS mapped above. */
-#endif
-
-#if defined(__HAVE_TLS_VARIANT_I) || defined(__HAVE_TLS_VARIANT_II)
- if (phtls != NULL)
- obj->tlsinit = mapbase + tls_vaddr;
-#endif
-
- obj->mapbase = mapbase;
- obj->mapsize = mapsize;
- obj->relocbase = mapbase - base_vaddr;
-
- if (obj->dynamic)
- obj->dynamic = (void *)(obj->relocbase + (Elf_Addr)(uintptr_t)obj->dynamic);
- if (obj->entry)
- obj->entry = (void *)(obj->relocbase + (Elf_Addr)(uintptr_t)obj->entry);
- if (obj->interp)
- obj->interp = (void *)(obj->relocbase + (Elf_Addr)(uintptr_t)obj->interp);
- if (obj->phdr_loaded)
- obj->phdr = (void *)(obj->relocbase + (Elf_Addr)(uintptr_t)obj->phdr);
-#ifdef __ARM_EABI__
- if (obj->exidx_start)
- obj->exidx_start = (void *)(obj->relocbase + (Elf_Addr)(uintptr_t)obj->exidx_start);
-#endif
-
- return obj;
-
-bad:
- if (obj->ehdr != MAP_FAILED)
- munmap(obj->ehdr, _rtld_pagesz);
- if (mapbase != MAP_FAILED)
- munmap(mapbase, mapsize);
- _rtld_obj_free(obj);
- return NULL;
-}
-
-#if !defined(__minix)
-/*
- * Given a set of ELF protection flags, return the corresponding protection
- * flags for MMAP.
- */
-static int
-protflags(int elfflags)
-{
- int prot = 0;
-
- if (elfflags & PF_R)
- prot |= PROT_READ;
-#ifdef RTLD_LOADER
- if (elfflags & PF_W)
- prot |= PROT_WRITE;
-#endif
- if (elfflags & PF_X)
- prot |= PROT_EXEC;
-#if defined(__minix)
- /* Minix has to map it writable so we can do relocations
- * as we don't have mprotect() yet.
- */
- prot |= PROT_WRITE;
-#endif /* defined(__minix) */
- return prot;
-}
-#endif /* defined(__minix) */