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ld.elf_so: Drop fallback routine

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Change-Id: Ia2236146c3302ba992aa6fea0fc9e9699fe9e3cd
This commit is contained in:
Lionel Sambuc 2015-12-30 09:16:54 +01:00
parent ef31660ff2
commit 2988757685
5 changed files with 3 additions and 538 deletions
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4
libexec/ld.elf_so/Makefile
View File

@ -76,10 +76,6 @@ SRCS+= rtld.c reloc.c symbol.c xmalloc.c xprintf.c debug.c \
map_object.c load.c search.c headers.c paths.c expand.c \ map_object.c load.c search.c headers.c paths.c expand.c \
tls.c symver.c diagassert.c tls.c symver.c diagassert.c
.if defined(__MINIX)
SRCS+= map_object_fallback.c
.endif # defined(__MINIX)
.if ${USE_FORT} == "yes" .if ${USE_FORT} == "yes"
.PATH.c: ${NETBSDSRCDIR}/lib/libc/misc .PATH.c: ${NETBSDSRCDIR}/lib/libc/misc
SRCS+= stack_protector.c SRCS+= stack_protector.c

24
libexec/ld.elf_so/map_object.c
View File

@ -49,15 +49,6 @@ __RCSID("$NetBSD: map_object.c,v 1.53 2014/10/30 07:53:41 martin Exp $");
#include "debug.h" #include "debug.h"
#include "rtld.h" #include "rtld.h"
#if defined(__minix)
#define MINIXVERBOSE 0
#if MINIXVERBOSE
#include <stdio.h>
#endif
#endif /* defined(__minix) */
static int protflags(int); /* Elf flags -> mmap protection */ static int protflags(int); /* Elf flags -> mmap protection */
#define EA_UNDEF (~(Elf_Addr)0) #define EA_UNDEF (~(Elf_Addr)0)
@ -114,9 +105,6 @@ _rtld_map_object(const char *path, int fd, const struct stat *sb)
caddr_t clear_addr; caddr_t clear_addr;
size_t nclear; size_t nclear;
#endif #endif
#if defined(__minix)
Elf_Addr bsslen;
#endif /* defined(__minix) */
if (sb != NULL && sb->st_size < (off_t)sizeof (Elf_Ehdr)) { if (sb != NULL && sb->st_size < (off_t)sizeof (Elf_Ehdr)) {
_rtld_error("%s: not ELF file (too short)", path); _rtld_error("%s: not ELF file (too short)", path);
@ -135,12 +123,8 @@ _rtld_map_object(const char *path, int fd, const struct stat *sb)
(off_t)0); (off_t)0);
obj->ehdr = ehdr; obj->ehdr = ehdr;
if (ehdr == MAP_FAILED) { if (ehdr == MAP_FAILED) {
#if defined(__minix)
return _rtld_map_object_fallback(path, fd, sb);
#else
_rtld_error("%s: read error: %s", path, xstrerror(errno)); _rtld_error("%s: read error: %s", path, xstrerror(errno));
goto bad; goto bad;
#endif /* defined(__minix) */
} }
/* Make sure the file is valid */ /* Make sure the file is valid */
if (memcmp(ELFMAG, ehdr->e_ident, SELFMAG) != 0) { if (memcmp(ELFMAG, ehdr->e_ident, SELFMAG) != 0) {
@ -373,12 +357,10 @@ _rtld_map_object(const char *path, int fd, const struct stat *sb)
/* Overlay the bss segment onto the proper region. */ /* Overlay the bss segment onto the proper region. */
#if defined(__minix) #if defined(__minix)
bsslen = base_vlimit - data_vlimit; /* MINIX's mmap is strict and refuses 0-bytes mappings. */
if (bsslen > 0 && if (0 < base_vlimit - data_vlimit)
mmap(mapbase + data_vlimit - base_vaddr, bsslen, #endif /*defined(__minix) */
#else
if (mmap(mapbase + data_vlimit - base_vaddr, base_vlimit - data_vlimit, if (mmap(mapbase + data_vlimit - base_vaddr, base_vlimit - data_vlimit,
#endif /* defined(__minix) */
data_flags, MAP_ANON | MAP_PRIVATE | MAP_FIXED, -1, 0) == data_flags, MAP_ANON | MAP_PRIVATE | MAP_FIXED, -1, 0) ==
MAP_FAILED) { MAP_FAILED) {
_rtld_error("mmap of bss failed: %s", xstrerror(errno)); _rtld_error("mmap of bss failed: %s", xstrerror(errno));

506
libexec/ld.elf_so/map_object_fallback.c
View File

@ -1,506 +0,0 @@
/* $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) */

3
libexec/ld.elf_so/rtld.h
View File

@ -472,9 +472,6 @@ __dso_public extern void *___tls_get_addr(void *)
/* map_object.c */ /* map_object.c */
struct stat; struct stat;
Obj_Entry *_rtld_map_object(const char *, int, const struct stat *); Obj_Entry *_rtld_map_object(const char *, int, const struct stat *);
#if defined(__minix)
Obj_Entry *_rtld_map_object_fallback(const char *, int, const struct stat *);
#endif /* defined(__minix) */
void _rtld_obj_free(Obj_Entry *); void _rtld_obj_free(Obj_Entry *);
Obj_Entry *_rtld_obj_new(void); Obj_Entry *_rtld_obj_new(void);

4
usr.bin/ldd/Makefile.elf
View File

@ -7,8 +7,4 @@ SRCS= ldd_elfxx.c
SRCS+= xmalloc.c debug.c expand.c map_object.c load.c search.c \ SRCS+= xmalloc.c debug.c expand.c map_object.c load.c search.c \
headers.c paths.c tls.c symver.c headers.c paths.c tls.c symver.c
.if defined(__MINIX)
SRCS+= map_object_fallback.c
.endif # defined(__MINIX)
.include "Makefile.common" .include "Makefile.common"