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link_elf.c
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/*-
* SPDX-License-Identifier: BSD-2-Clause-FreeBSD
*
* Copyright (c) 1998-2000 Doug Rabson
* 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.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``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 OR CONTRIBUTORS 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>
__FBSDID("$FreeBSD$");
#include "opt_ddb.h"
#include "opt_gdb.h"
#include <sys/param.h>
#include <sys/systm.h>
#ifdef GPROF
#include <sys/gmon.h>
#endif
#include <sys/kernel.h>
#include <sys/lock.h>
#include <sys/malloc.h>
#include <sys/mutex.h>
#include <sys/mount.h>
#include <sys/pcpu.h>
#include <sys/proc.h>
#include <sys/namei.h>
#include <sys/fcntl.h>
#include <sys/vnode.h>
#include <sys/linker.h>
#include <machine/elf.h>
#include <net/vnet.h>
#include <security/mac/mac_framework.h>
#include <vm/vm.h>
#include <vm/vm_param.h>
#ifdef SPARSE_MAPPING
#include <vm/vm_object.h>
#include <vm/vm_kern.h>
#include <vm/vm_extern.h>
#endif
#include <vm/pmap.h>
#include <vm/vm_map.h>
#include <sys/link_elf.h>
#ifdef DDB_CTF
#include <sys/zlib.h>
#endif
#include "linker_if.h"
#define MAXSEGS 4
typedef struct elf_file {
struct linker_file lf; /* Common fields */
int preloaded; /* Was file pre-loaded */
caddr_t address; /* Relocation address */
#ifdef SPARSE_MAPPING
vm_object_t object; /* VM object to hold file pages */
#endif
Elf_Dyn *dynamic; /* Symbol table etc. */
Elf_Hashelt nbuckets; /* DT_HASH info */
Elf_Hashelt nchains;
const Elf_Hashelt *buckets;
const Elf_Hashelt *chains;
caddr_t hash;
caddr_t strtab; /* DT_STRTAB */
int strsz; /* DT_STRSZ */
const Elf_Sym *symtab; /* DT_SYMTAB */
Elf_Addr *got; /* DT_PLTGOT */
const Elf_Rel *pltrel; /* DT_JMPREL */
int pltrelsize; /* DT_PLTRELSZ */
const Elf_Rela *pltrela; /* DT_JMPREL */
int pltrelasize; /* DT_PLTRELSZ */
const Elf_Rel *rel; /* DT_REL */
int relsize; /* DT_RELSZ */
const Elf_Rela *rela; /* DT_RELA */
int relasize; /* DT_RELASZ */
caddr_t modptr;
const Elf_Sym *ddbsymtab; /* The symbol table we are using */
long ddbsymcnt; /* Number of symbols */
caddr_t ddbstrtab; /* String table */
long ddbstrcnt; /* number of bytes in string table */
caddr_t symbase; /* malloc'ed symbold base */
caddr_t strbase; /* malloc'ed string base */
caddr_t ctftab; /* CTF table */
long ctfcnt; /* number of bytes in CTF table */
caddr_t ctfoff; /* CTF offset table */
caddr_t typoff; /* Type offset table */
long typlen; /* Number of type entries. */
Elf_Addr pcpu_start; /* Pre-relocation pcpu set start. */
Elf_Addr pcpu_stop; /* Pre-relocation pcpu set stop. */
Elf_Addr pcpu_base; /* Relocated pcpu set address. */
#ifdef VIMAGE
Elf_Addr vnet_start; /* Pre-relocation vnet set start. */
Elf_Addr vnet_stop; /* Pre-relocation vnet set stop. */
Elf_Addr vnet_base; /* Relocated vnet set address. */
#endif
#ifdef GDB
struct link_map gdb; /* hooks for gdb */
#endif
} *elf_file_t;
struct elf_set {
Elf_Addr es_start;
Elf_Addr es_stop;
Elf_Addr es_base;
TAILQ_ENTRY(elf_set) es_link;
};
TAILQ_HEAD(elf_set_head, elf_set);
#include <kern/kern_ctf.c>
static int link_elf_link_common_finish(linker_file_t);
static int link_elf_link_preload(linker_class_t cls,
const char *, linker_file_t *);
static int link_elf_link_preload_finish(linker_file_t);
static int link_elf_load_file(linker_class_t, const char *,
linker_file_t *);
static int link_elf_lookup_symbol(linker_file_t, const char *,
c_linker_sym_t *);
static int link_elf_symbol_values(linker_file_t, c_linker_sym_t,
linker_symval_t *);
static int link_elf_search_symbol(linker_file_t, caddr_t,
c_linker_sym_t *, long *);
static void link_elf_unload_file(linker_file_t);
static void link_elf_unload_preload(linker_file_t);
static int link_elf_lookup_set(linker_file_t, const char *,
void ***, void ***, int *);
static int link_elf_each_function_name(linker_file_t,
int (*)(const char *, void *), void *);
static int link_elf_each_function_nameval(linker_file_t,
linker_function_nameval_callback_t, void *);
static void link_elf_reloc_local(linker_file_t);
static long link_elf_symtab_get(linker_file_t, const Elf_Sym **);
static long link_elf_strtab_get(linker_file_t, caddr_t *);
static int elf_lookup(linker_file_t, Elf_Size, int, Elf_Addr *);
static kobj_method_t link_elf_methods[] = {
KOBJMETHOD(linker_lookup_symbol, link_elf_lookup_symbol),
KOBJMETHOD(linker_symbol_values, link_elf_symbol_values),
KOBJMETHOD(linker_search_symbol, link_elf_search_symbol),
KOBJMETHOD(linker_unload, link_elf_unload_file),
KOBJMETHOD(linker_load_file, link_elf_load_file),
KOBJMETHOD(linker_link_preload, link_elf_link_preload),
KOBJMETHOD(linker_link_preload_finish, link_elf_link_preload_finish),
KOBJMETHOD(linker_lookup_set, link_elf_lookup_set),
KOBJMETHOD(linker_each_function_name, link_elf_each_function_name),
KOBJMETHOD(linker_each_function_nameval, link_elf_each_function_nameval),
KOBJMETHOD(linker_ctf_get, link_elf_ctf_get),
KOBJMETHOD(linker_symtab_get, link_elf_symtab_get),
KOBJMETHOD(linker_strtab_get, link_elf_strtab_get),
{ 0, 0 }
};
static struct linker_class link_elf_class = {
#if ELF_TARG_CLASS == ELFCLASS32
"elf32",
#else
"elf64",
#endif
link_elf_methods, sizeof(struct elf_file)
};
typedef int (*elf_reloc_fn)(linker_file_t lf, Elf_Addr relocbase,
const void *data, int type, elf_lookup_fn lookup);
static int parse_dynamic(elf_file_t);
static int relocate_file(elf_file_t);
static int relocate_file1(elf_file_t ef, elf_lookup_fn lookup,
elf_reloc_fn reloc, bool ifuncs);
static int link_elf_preload_parse_symbols(elf_file_t);
static struct elf_set_head set_pcpu_list;
#ifdef VIMAGE
static struct elf_set_head set_vnet_list;
#endif
static void
elf_set_add(struct elf_set_head *list, Elf_Addr start, Elf_Addr stop, Elf_Addr base)
{
struct elf_set *set, *iter;
set = malloc(sizeof(*set), M_LINKER, M_WAITOK);
set->es_start = start;
set->es_stop = stop;
set->es_base = base;
TAILQ_FOREACH(iter, list, es_link) {
KASSERT((set->es_start < iter->es_start && set->es_stop < iter->es_stop) ||
(set->es_start > iter->es_start && set->es_stop > iter->es_stop),
("linker sets intersection: to insert: 0x%jx-0x%jx; inserted: 0x%jx-0x%jx",
(uintmax_t)set->es_start, (uintmax_t)set->es_stop,
(uintmax_t)iter->es_start, (uintmax_t)iter->es_stop));
if (iter->es_start > set->es_start) {
TAILQ_INSERT_BEFORE(iter, set, es_link);
break;
}
}
if (iter == NULL)
TAILQ_INSERT_TAIL(list, set, es_link);
}
static int
elf_set_find(struct elf_set_head *list, Elf_Addr addr, Elf_Addr *start, Elf_Addr *base)
{
struct elf_set *set;
TAILQ_FOREACH(set, list, es_link) {
if (addr < set->es_start)
return (0);
if (addr < set->es_stop) {
*start = set->es_start;
*base = set->es_base;
return (1);
}
}
return (0);
}
static void
elf_set_delete(struct elf_set_head *list, Elf_Addr start)
{
struct elf_set *set;
TAILQ_FOREACH(set, list, es_link) {
if (start < set->es_start)
break;
if (start == set->es_start) {
TAILQ_REMOVE(list, set, es_link);
free(set, M_LINKER);
return;
}
}
KASSERT(0, ("deleting unknown linker set (start = 0x%jx)",
(uintmax_t)start));
}
#ifdef GDB
static void r_debug_state(struct r_debug *, struct link_map *);
/*
* A list of loaded modules for GDB to use for loading symbols.
*/
struct r_debug r_debug;
#define GDB_STATE(s) do { \
r_debug.r_state = s; r_debug_state(NULL, NULL); \
} while (0)
/*
* Function for the debugger to set a breakpoint on to gain control.
*/
static void
r_debug_state(struct r_debug *dummy_one __unused,
struct link_map *dummy_two __unused)
{
}
static void
link_elf_add_gdb(struct link_map *l)
{
struct link_map *prev;
l->l_next = NULL;
if (r_debug.r_map == NULL) {
/* Add first. */
l->l_prev = NULL;
r_debug.r_map = l;
} else {
/* Append to list. */
for (prev = r_debug.r_map;
prev->l_next != NULL;
prev = prev->l_next)
;
l->l_prev = prev;
prev->l_next = l;
}
}
static void
link_elf_delete_gdb(struct link_map *l)
{
if (l->l_prev == NULL) {
/* Remove first. */
if ((r_debug.r_map = l->l_next) != NULL)
l->l_next->l_prev = NULL;
} else {
/* Remove any but first. */
if ((l->l_prev->l_next = l->l_next) != NULL)
l->l_next->l_prev = l->l_prev;
}
}
#endif /* GDB */
/*
* The kernel symbol table starts here.
*/
extern struct _dynamic _DYNAMIC;
static void
link_elf_error(const char *filename, const char *s)
{
if (filename == NULL)
printf("kldload: %s\n", s);
else
printf("kldload: %s: %s\n", filename, s);
}
static void
link_elf_invoke_ctors(caddr_t addr, size_t size)
{
void (**ctor)(void);
size_t i, cnt;
if (addr == NULL || size == 0)
return;
cnt = size / sizeof(*ctor);
ctor = (void *)addr;
for (i = 0; i < cnt; i++) {
if (ctor[i] != NULL)
(*ctor[i])();
}
}
/*
* Actions performed after linking/loading both the preloaded kernel and any
* modules; whether preloaded or dynamicly loaded.
*/
static int
link_elf_link_common_finish(linker_file_t lf)
{
#ifdef GDB
elf_file_t ef = (elf_file_t)lf;
char *newfilename;
#endif
int error;
/* Notify MD code that a module is being loaded. */
error = elf_cpu_load_file(lf);
if (error != 0)
return (error);
#ifdef GDB
GDB_STATE(RT_ADD);
ef->gdb.l_addr = lf->address;
newfilename = malloc(strlen(lf->filename) + 1, M_LINKER, M_WAITOK);
strcpy(newfilename, lf->filename);
ef->gdb.l_name = newfilename;
ef->gdb.l_ld = ef->dynamic;
link_elf_add_gdb(&ef->gdb);
GDB_STATE(RT_CONSISTENT);
#endif
/* Invoke .ctors */
link_elf_invoke_ctors(lf->ctors_addr, lf->ctors_size);
return (0);
}
extern vm_offset_t __startkernel, __endkernel;
static void
link_elf_init(void* arg)
{
Elf_Dyn *dp;
Elf_Addr *ctors_addrp;
Elf_Size *ctors_sizep;
caddr_t modptr, baseptr, sizeptr;
elf_file_t ef;
char *modname;
linker_add_class(&link_elf_class);
dp = (Elf_Dyn *)&_DYNAMIC;
modname = NULL;
modptr = preload_search_by_type("elf" __XSTRING(__ELF_WORD_SIZE) " kernel");
if (modptr == NULL)
modptr = preload_search_by_type("elf kernel");
modname = (char *)preload_search_info(modptr, MODINFO_NAME);
if (modname == NULL)
modname = "kernel";
linker_kernel_file = linker_make_file(modname, &link_elf_class);
if (linker_kernel_file == NULL)
panic("%s: Can't create linker structures for kernel",
__func__);
ef = (elf_file_t) linker_kernel_file;
ef->preloaded = 1;
#ifdef __powerpc__
ef->address = (caddr_t) (__startkernel - KERNBASE);
#else
ef->address = 0;
#endif
#ifdef SPARSE_MAPPING
ef->object = 0;
#endif
ef->dynamic = dp;
if (dp != NULL)
parse_dynamic(ef);
#ifdef __powerpc__
linker_kernel_file->address = (caddr_t)__startkernel;
linker_kernel_file->size = (intptr_t)(__endkernel - __startkernel);
#else
linker_kernel_file->address += KERNBASE;
linker_kernel_file->size = -(intptr_t)linker_kernel_file->address;
#endif
if (modptr != NULL) {
ef->modptr = modptr;
baseptr = preload_search_info(modptr, MODINFO_ADDR);
if (baseptr != NULL)
linker_kernel_file->address = *(caddr_t *)baseptr;
sizeptr = preload_search_info(modptr, MODINFO_SIZE);
if (sizeptr != NULL)
linker_kernel_file->size = *(size_t *)sizeptr;
ctors_addrp = (Elf_Addr *)preload_search_info(modptr,
MODINFO_METADATA | MODINFOMD_CTORS_ADDR);
ctors_sizep = (Elf_Size *)preload_search_info(modptr,
MODINFO_METADATA | MODINFOMD_CTORS_SIZE);
if (ctors_addrp != NULL && ctors_sizep != NULL) {
linker_kernel_file->ctors_addr = ef->address +
*ctors_addrp;
linker_kernel_file->ctors_size = *ctors_sizep;
}
}
(void)link_elf_preload_parse_symbols(ef);
#ifdef GDB
r_debug.r_map = NULL;
r_debug.r_brk = r_debug_state;
r_debug.r_state = RT_CONSISTENT;
#endif
(void)link_elf_link_common_finish(linker_kernel_file);
linker_kernel_file->flags |= LINKER_FILE_LINKED;
TAILQ_INIT(&set_pcpu_list);
#ifdef VIMAGE
TAILQ_INIT(&set_vnet_list);
#endif
}
SYSINIT(link_elf, SI_SUB_KLD, SI_ORDER_THIRD, link_elf_init, NULL);
static int
link_elf_preload_parse_symbols(elf_file_t ef)
{
caddr_t pointer;
caddr_t ssym, esym, base;
caddr_t strtab;
int strcnt;
Elf_Sym *symtab;
int symcnt;
if (ef->modptr == NULL)
return (0);
pointer = preload_search_info(ef->modptr,
MODINFO_METADATA | MODINFOMD_SSYM);
if (pointer == NULL)
return (0);
ssym = *(caddr_t *)pointer;
pointer = preload_search_info(ef->modptr,
MODINFO_METADATA | MODINFOMD_ESYM);
if (pointer == NULL)
return (0);
esym = *(caddr_t *)pointer;
base = ssym;
symcnt = *(long *)base;
base += sizeof(long);
symtab = (Elf_Sym *)base;
base += roundup(symcnt, sizeof(long));
if (base > esym || base < ssym) {
printf("Symbols are corrupt!\n");
return (EINVAL);
}
strcnt = *(long *)base;
base += sizeof(long);
strtab = base;
base += roundup(strcnt, sizeof(long));
if (base > esym || base < ssym) {
printf("Symbols are corrupt!\n");
return (EINVAL);
}
ef->ddbsymtab = symtab;
ef->ddbsymcnt = symcnt / sizeof(Elf_Sym);
ef->ddbstrtab = strtab;
ef->ddbstrcnt = strcnt;
return (0);
}
static int
parse_dynamic(elf_file_t ef)
{
Elf_Dyn *dp;
int plttype = DT_REL;
for (dp = ef->dynamic; dp->d_tag != DT_NULL; dp++) {
switch (dp->d_tag) {
case DT_HASH:
{
/* From src/libexec/rtld-elf/rtld.c */
const Elf_Hashelt *hashtab = (const Elf_Hashelt *)
(ef->address + dp->d_un.d_ptr);
ef->nbuckets = hashtab[0];
ef->nchains = hashtab[1];
ef->buckets = hashtab + 2;
ef->chains = ef->buckets + ef->nbuckets;
break;
}
case DT_STRTAB:
ef->strtab = (caddr_t) (ef->address + dp->d_un.d_ptr);
break;
case DT_STRSZ:
ef->strsz = dp->d_un.d_val;
break;
case DT_SYMTAB:
ef->symtab = (Elf_Sym*) (ef->address + dp->d_un.d_ptr);
break;
case DT_SYMENT:
if (dp->d_un.d_val != sizeof(Elf_Sym))
return (ENOEXEC);
break;
case DT_PLTGOT:
ef->got = (Elf_Addr *) (ef->address + dp->d_un.d_ptr);
break;
case DT_REL:
ef->rel = (const Elf_Rel *) (ef->address + dp->d_un.d_ptr);
break;
case DT_RELSZ:
ef->relsize = dp->d_un.d_val;
break;
case DT_RELENT:
if (dp->d_un.d_val != sizeof(Elf_Rel))
return (ENOEXEC);
break;
case DT_JMPREL:
ef->pltrel = (const Elf_Rel *) (ef->address + dp->d_un.d_ptr);
break;
case DT_PLTRELSZ:
ef->pltrelsize = dp->d_un.d_val;
break;
case DT_RELA:
ef->rela = (const Elf_Rela *) (ef->address + dp->d_un.d_ptr);
break;
case DT_RELASZ:
ef->relasize = dp->d_un.d_val;
break;
case DT_RELAENT:
if (dp->d_un.d_val != sizeof(Elf_Rela))
return (ENOEXEC);
break;
case DT_PLTREL:
plttype = dp->d_un.d_val;
if (plttype != DT_REL && plttype != DT_RELA)
return (ENOEXEC);
break;
#ifdef GDB
case DT_DEBUG:
dp->d_un.d_ptr = (Elf_Addr)&r_debug;
break;
#endif
}
}
if (plttype == DT_RELA) {
ef->pltrela = (const Elf_Rela *)ef->pltrel;
ef->pltrel = NULL;
ef->pltrelasize = ef->pltrelsize;
ef->pltrelsize = 0;
}
ef->ddbsymtab = ef->symtab;
ef->ddbsymcnt = ef->nchains;
ef->ddbstrtab = ef->strtab;
ef->ddbstrcnt = ef->strsz;
return (0);
}
static int
parse_dpcpu(elf_file_t ef)
{
int error, size;
ef->pcpu_start = 0;
ef->pcpu_stop = 0;
error = link_elf_lookup_set(&ef->lf, "pcpu", (void ***)&ef->pcpu_start,
(void ***)&ef->pcpu_stop, NULL);
/* Error just means there is no pcpu set to relocate. */
if (error != 0)
return (0);
size = (uintptr_t)ef->pcpu_stop - (uintptr_t)ef->pcpu_start;
/* Empty set? */
if (size < 1)
return (0);
/*
* Allocate space in the primary pcpu area. Copy in our
* initialization from the data section and then initialize
* all per-cpu storage from that.
*/
ef->pcpu_base = (Elf_Addr)(uintptr_t)dpcpu_alloc(size);
if (ef->pcpu_base == 0) {
printf("%s: pcpu module space is out of space; "
"cannot allocate %d for %s\n",
__func__, size, ef->lf.pathname);
return (ENOSPC);
}
memcpy((void *)ef->pcpu_base, (void *)ef->pcpu_start, size);
dpcpu_copy((void *)ef->pcpu_base, size);
elf_set_add(&set_pcpu_list, ef->pcpu_start, ef->pcpu_stop,
ef->pcpu_base);
return (0);
}
#ifdef VIMAGE
static int
parse_vnet(elf_file_t ef)
{
int error, size;
ef->vnet_start = 0;
ef->vnet_stop = 0;
error = link_elf_lookup_set(&ef->lf, "vnet", (void ***)&ef->vnet_start,
(void ***)&ef->vnet_stop, NULL);
/* Error just means there is no vnet data set to relocate. */
if (error != 0)
return (0);
size = (uintptr_t)ef->vnet_stop - (uintptr_t)ef->vnet_start;
/* Empty set? */
if (size < 1)
return (0);
/*
* Allocate space in the primary vnet area. Copy in our
* initialization from the data section and then initialize
* all per-vnet storage from that.
*/
ef->vnet_base = (Elf_Addr)(uintptr_t)vnet_data_alloc(size);
if (ef->vnet_base == 0) {
printf("%s: vnet module space is out of space; "
"cannot allocate %d for %s\n",
__func__, size, ef->lf.pathname);
return (ENOSPC);
}
memcpy((void *)ef->vnet_base, (void *)ef->vnet_start, size);
vnet_data_copy((void *)ef->vnet_base, size);
elf_set_add(&set_vnet_list, ef->vnet_start, ef->vnet_stop,
ef->vnet_base);
return (0);
}
#endif
static int
link_elf_link_preload(linker_class_t cls,
const char* filename, linker_file_t *result)
{
Elf_Addr *ctors_addrp;
Elf_Size *ctors_sizep;
caddr_t modptr, baseptr, sizeptr, dynptr;
char *type;
elf_file_t ef;
linker_file_t lf;
int error;
vm_offset_t dp;
/* Look to see if we have the file preloaded */
modptr = preload_search_by_name(filename);
if (modptr == NULL)
return (ENOENT);
type = (char *)preload_search_info(modptr, MODINFO_TYPE);
baseptr = preload_search_info(modptr, MODINFO_ADDR);
sizeptr = preload_search_info(modptr, MODINFO_SIZE);
dynptr = preload_search_info(modptr,
MODINFO_METADATA | MODINFOMD_DYNAMIC);
if (type == NULL ||
(strcmp(type, "elf" __XSTRING(__ELF_WORD_SIZE) " module") != 0 &&
strcmp(type, "elf module") != 0))
return (EFTYPE);
if (baseptr == NULL || sizeptr == NULL || dynptr == NULL)
return (EINVAL);
lf = linker_make_file(filename, &link_elf_class);
if (lf == NULL)
return (ENOMEM);
ef = (elf_file_t) lf;
ef->preloaded = 1;
ef->modptr = modptr;
ef->address = *(caddr_t *)baseptr;
#ifdef SPARSE_MAPPING
ef->object = 0;
#endif
dp = (vm_offset_t)ef->address + *(vm_offset_t *)dynptr;
ef->dynamic = (Elf_Dyn *)dp;
lf->address = ef->address;
lf->size = *(size_t *)sizeptr;
ctors_addrp = (Elf_Addr *)preload_search_info(modptr,
MODINFO_METADATA | MODINFOMD_CTORS_ADDR);
ctors_sizep = (Elf_Size *)preload_search_info(modptr,
MODINFO_METADATA | MODINFOMD_CTORS_SIZE);
if (ctors_addrp != NULL && ctors_sizep != NULL) {
lf->ctors_addr = ef->address + *ctors_addrp;
lf->ctors_size = *ctors_sizep;
}
error = parse_dynamic(ef);
if (error == 0)
error = parse_dpcpu(ef);
#ifdef VIMAGE
if (error == 0)
error = parse_vnet(ef);
#endif
if (error != 0) {
linker_file_unload(lf, LINKER_UNLOAD_FORCE);
return (error);
}
link_elf_reloc_local(lf);
*result = lf;
return (0);
}
static int
link_elf_link_preload_finish(linker_file_t lf)
{
elf_file_t ef;
int error;
ef = (elf_file_t) lf;
error = relocate_file(ef);
if (error != 0)
return (error);
(void)link_elf_preload_parse_symbols(ef);
return (link_elf_link_common_finish(lf));
}
static int
link_elf_load_file(linker_class_t cls, const char* filename,
linker_file_t* result)
{
struct nameidata nd;
struct thread* td = curthread; /* XXX */
Elf_Ehdr *hdr;
caddr_t firstpage;
int nbytes, i;
Elf_Phdr *phdr;
Elf_Phdr *phlimit;
Elf_Phdr *segs[MAXSEGS];
int nsegs;
Elf_Phdr *phdyn;
caddr_t mapbase;
size_t mapsize;
Elf_Addr base_vaddr;
Elf_Addr base_vlimit;
int error = 0;
ssize_t resid;
int flags;
elf_file_t ef;
linker_file_t lf;
Elf_Shdr *shdr;
int symtabindex;
int symstrindex;
int shstrindex;
int symcnt;
int strcnt;
char *shstrs;
shdr = NULL;
lf = NULL;
shstrs = NULL;
NDINIT(&nd, LOOKUP, FOLLOW, UIO_SYSSPACE, filename, td);
flags = FREAD;
error = vn_open(&nd, &flags, 0, NULL);
if (error != 0)
return (error);
NDFREE(&nd, NDF_ONLY_PNBUF);
if (nd.ni_vp->v_type != VREG) {
error = ENOEXEC;
firstpage = NULL;
goto out;
}
#ifdef MAC
error = mac_kld_check_load(curthread->td_ucred, nd.ni_vp);
if (error != 0) {
firstpage = NULL;
goto out;
}
#endif
/*
* Read the elf header from the file.
*/
firstpage = malloc(PAGE_SIZE, M_LINKER, M_WAITOK);
hdr = (Elf_Ehdr *)firstpage;
error = vn_rdwr(UIO_READ, nd.ni_vp, firstpage, PAGE_SIZE, 0,
UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, NOCRED,
&resid, td);
nbytes = PAGE_SIZE - resid;
if (error != 0)
goto out;
if (!IS_ELF(*hdr)) {
error = ENOEXEC;
goto out;
}
if (hdr->e_ident[EI_CLASS] != ELF_TARG_CLASS ||
hdr->e_ident[EI_DATA] != ELF_TARG_DATA) {
link_elf_error(filename, "Unsupported file layout");
error = ENOEXEC;
goto out;
}
if (hdr->e_ident[EI_VERSION] != EV_CURRENT ||
hdr->e_version != EV_CURRENT) {
link_elf_error(filename, "Unsupported file version");
error = ENOEXEC;
goto out;
}
if (hdr->e_type != ET_EXEC && hdr->e_type != ET_DYN) {
error = ENOSYS;
goto out;
}
if (hdr->e_machine != ELF_TARG_MACH) {
link_elf_error(filename, "Unsupported machine");
error = ENOEXEC;
goto out;
}
/*
* 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.
*/
if (!((hdr->e_phentsize == sizeof(Elf_Phdr)) &&
(hdr->e_phoff + hdr->e_phnum*sizeof(Elf_Phdr) <= PAGE_SIZE) &&
(hdr->e_phoff + hdr->e_phnum*sizeof(Elf_Phdr) <= nbytes)))
link_elf_error(filename, "Unreadable program headers");
/*
* 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 *) (firstpage + hdr->e_phoff);
phlimit = phdr + hdr->e_phnum;
nsegs = 0;
phdyn = NULL;
while (phdr < phlimit) {
switch (phdr->p_type) {
case PT_LOAD:
if (nsegs == MAXSEGS) {
link_elf_error(filename, "Too many sections");
error = ENOEXEC;
goto out;
}
/*
* XXX: We just trust they come in right order ??
*/
segs[nsegs] = phdr;
++nsegs;
break;
case PT_DYNAMIC:
phdyn = phdr;
break;
case PT_INTERP:
error = ENOSYS;
goto out;
}
++phdr;
}
if (phdyn == NULL) {
link_elf_error(filename, "Object is not dynamically-linked");
error = ENOEXEC;
goto out;
}
if (nsegs == 0) {
link_elf_error(filename, "No sections");
error = ENOEXEC;
goto out;
}
/*
* Allocate the entire address space of the object, to stake
* out our contiguous region, and to establish the base
* address for relocation.
*/
base_vaddr = trunc_page(segs[0]->p_vaddr);
base_vlimit = round_page(segs[nsegs - 1]->p_vaddr +
segs[nsegs - 1]->p_memsz);
mapsize = base_vlimit - base_vaddr;
lf = linker_make_file(filename, &link_elf_class);
if (lf == NULL) {
error = ENOMEM;
goto out;
}
ef = (elf_file_t) lf;
#ifdef SPARSE_MAPPING
ef->object = vm_object_allocate(OBJT_DEFAULT, mapsize >> PAGE_SHIFT);
if (ef->object == NULL) {
error = ENOMEM;
goto out;
}
ef->address = (caddr_t) vm_map_min(kernel_map);
error = vm_map_find(kernel_map, ef->object, 0,
(vm_offset_t *) &ef->address, mapsize, 0, VMFS_OPTIMAL_SPACE,
VM_PROT_ALL, VM_PROT_ALL, 0);
if (error != 0) {
vm_object_deallocate(ef->object);
ef->object = 0;
goto out;
}
#else
ef->address = malloc(mapsize, M_LINKER, M_EXEC | M_WAITOK);
#endif
mapbase = ef->address;
/*
* Read the text and data sections and zero the bss.
*/
for (i = 0; i < nsegs; i++) {
caddr_t segbase = mapbase + segs[i]->p_vaddr - base_vaddr;
error = vn_rdwr(UIO_READ, nd.ni_vp,
segbase, segs[i]->p_filesz, segs[i]->p_offset,
UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, NOCRED,
&resid, td);
if (error != 0)
goto out;
bzero(segbase + segs[i]->p_filesz,
segs[i]->p_memsz - segs[i]->p_filesz);
#ifdef SPARSE_MAPPING
/*
* Wire down the pages
*/
error = vm_map_wire(kernel_map,
(vm_offset_t) segbase,
(vm_offset_t) segbase + segs[i]->p_memsz,
VM_MAP_WIRE_SYSTEM|VM_MAP_WIRE_NOHOLES);
if (error != KERN_SUCCESS) {
error = ENOMEM;
goto out;
}
#endif
}
#ifdef GPROF
/* Update profiling information with the new text segment. */
mtx_lock(&Giant);
kmupetext((uintfptr_t)(mapbase + segs[0]->p_vaddr - base_vaddr +
segs[0]->p_memsz));
mtx_unlock(&Giant);