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freebsd/sys/boot/common/load_elf.c
Andrew Turner 35ad131a2a Don't set the offset when loading the kernel on the arm loader.efi. The 
copyin and copyout code handle virtual addresses such that they will take
a virtual address and convert it into a valid physical address. It may
also mean we fail to boot as the elf files load address could be 0.

Sponsored by:	ABT Systems Ltd
2016-02-09 09:39:30 +00:00

1039 lines
28 KiB
C
Raw Blame History

/*-
* Copyright (c) 1998 Michael Smith <msmith@freebsd.org>
* Copyright (c) 1998 Peter Wemm <peter@freebsd.org>
* 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 <sys/param.h>
#include <sys/exec.h>
#include <sys/linker.h>
#include <sys/module.h>
#include <sys/stdint.h>
#include <string.h>
#include <machine/elf.h>
#include <stand.h>
#define FREEBSD_ELF
#include <link.h>
#include "bootstrap.h"
#define COPYOUT(s,d,l) archsw.arch_copyout((vm_offset_t)(s), d, l)
#if defined(__i386__) && __ELF_WORD_SIZE == 64
#undef ELF_TARG_CLASS
#undef ELF_TARG_MACH
#define ELF_TARG_CLASS ELFCLASS64
#define ELF_TARG_MACH EM_X86_64
#endif
typedef struct elf_file {
Elf_Phdr *ph;
Elf_Ehdr *ehdr;
Elf_Sym *symtab;
Elf_Hashelt *hashtab;
Elf_Hashelt nbuckets;
Elf_Hashelt nchains;
Elf_Hashelt *buckets;
Elf_Hashelt *chains;
Elf_Rel *rel;
size_t relsz;
Elf_Rela *rela;
size_t relasz;
char *strtab;
size_t strsz;
int fd;
caddr_t firstpage;
size_t firstlen;
int kernel;
u_int64_t off;
} *elf_file_t;
static int __elfN(loadimage)(struct preloaded_file *mp, elf_file_t ef, u_int64_t loadaddr);
static int __elfN(lookup_symbol)(struct preloaded_file *mp, elf_file_t ef, const char* name, Elf_Sym* sym);
static int __elfN(reloc_ptr)(struct preloaded_file *mp, elf_file_t ef,
Elf_Addr p, void *val, size_t len);
static int __elfN(parse_modmetadata)(struct preloaded_file *mp, elf_file_t ef,
Elf_Addr p_start, Elf_Addr p_end);
static symaddr_fn __elfN(symaddr);
static char *fake_modname(const char *name);
const char *__elfN(kerneltype) = "elf kernel";
const char *__elfN(moduletype) = "elf module";
u_int64_t __elfN(relocation_offset) = 0;
static int
__elfN(load_elf_header)(char *filename, elf_file_t ef)
{
ssize_t bytes_read;
Elf_Ehdr *ehdr;
int err;
/*
* Open the image, read and validate the ELF header
*/
if (filename == NULL) /* can't handle nameless */
return (EFTYPE);
if ((ef->fd = open(filename, O_RDONLY)) == -1)
return (errno);
ef->firstpage = malloc(PAGE_SIZE);
if (ef->firstpage == NULL) {
close(ef->fd);
return (ENOMEM);
}
bytes_read = read(ef->fd, ef->firstpage, PAGE_SIZE);
ef->firstlen = (size_t)bytes_read;
if (bytes_read < 0 || ef->firstlen <= sizeof(Elf_Ehdr)) {
err = EFTYPE; /* could be EIO, but may be small file */
goto error;
}
ehdr = ef->ehdr = (Elf_Ehdr *)ef->firstpage;
/* Is it ELF? */
if (!IS_ELF(*ehdr)) {
err = EFTYPE;
goto error;
}
if (ehdr->e_ident[EI_CLASS] != ELF_TARG_CLASS || /* Layout ? */
ehdr->e_ident[EI_DATA] != ELF_TARG_DATA ||
ehdr->e_ident[EI_VERSION] != EV_CURRENT || /* Version ? */
ehdr->e_version != EV_CURRENT ||
ehdr->e_machine != ELF_TARG_MACH) { /* Machine ? */
err = EFTYPE;
goto error;
}
return (0);
error:
if (ef->firstpage != NULL) {
free(ef->firstpage);
ef->firstpage = NULL;
}
if (ef->fd != -1) {
close(ef->fd);
ef->fd = -1;
}
return (err);
}
/*
* Attempt to load the file (file) as an ELF module. It will be stored at
* (dest), and a pointer to a module structure describing the loaded object
* will be saved in (result).
*/
int
__elfN(loadfile)(char *filename, u_int64_t dest, struct preloaded_file **result)
{
return (__elfN(loadfile_raw)(filename, dest, result, 0));
}
int
__elfN(loadfile_raw)(char *filename, u_int64_t dest,
struct preloaded_file **result, int multiboot)
{
struct preloaded_file *fp, *kfp;
struct elf_file ef;
Elf_Ehdr *ehdr;
int err;
fp = NULL;
bzero(&ef, sizeof(struct elf_file));
ef.fd = -1;
err = __elfN(load_elf_header)(filename, &ef);
if (err != 0)
return (err);
ehdr = ef.ehdr;
/*
* Check to see what sort of module we are.
*/
kfp = file_findfile(NULL, __elfN(kerneltype));
#ifdef __powerpc__
/*
* Kernels can be ET_DYN, so just assume the first loaded object is the
* kernel. This assumption will be checked later.
*/
if (kfp == NULL)
ef.kernel = 1;
#endif
if (ef.kernel || ehdr->e_type == ET_EXEC) {
/* Looks like a kernel */
if (kfp != NULL) {
printf("elf" __XSTRING(__ELF_WORD_SIZE) "_loadfile: kernel already loaded\n");
err = EPERM;
goto oerr;
}
/*
* Calculate destination address based on kernel entrypoint.
*
* For ARM, the destination address is independent of any values in the
* elf header (an ARM kernel can be loaded at any 2MB boundary), so we
* leave dest set to the value calculated by archsw.arch_loadaddr() and
* passed in to this function.
*/
#ifndef __arm__
if (ehdr->e_type == ET_EXEC)
dest = (ehdr->e_entry & ~PAGE_MASK);
#endif
if ((ehdr->e_entry & ~PAGE_MASK) == 0) {
printf("elf" __XSTRING(__ELF_WORD_SIZE) "_loadfile: not a kernel (maybe static binary?)\n");
err = EPERM;
goto oerr;
}
ef.kernel = 1;
} else if (ehdr->e_type == ET_DYN) {
/* Looks like a kld module */
if (multiboot != 0) {
printf("elf" __XSTRING(__ELF_WORD_SIZE) "_loadfile: can't load module as multiboot\n");
err = EPERM;
goto oerr;
}
if (kfp == NULL) {
printf("elf" __XSTRING(__ELF_WORD_SIZE) "_loadfile: can't load module before kernel\n");
err = EPERM;
goto oerr;
}
if (strcmp(__elfN(kerneltype), kfp->f_type)) {
printf("elf" __XSTRING(__ELF_WORD_SIZE) "_loadfile: can't load module with kernel type '%s'\n", kfp->f_type);
err = EPERM;
goto oerr;
}
/* Looks OK, got ahead */
ef.kernel = 0;
} else {
err = EFTYPE;
goto oerr;
}
if (archsw.arch_loadaddr != NULL)
dest = archsw.arch_loadaddr(LOAD_ELF, ehdr, dest);
else
dest = roundup(dest, PAGE_SIZE);
/*
* Ok, we think we should handle this.
*/
fp = file_alloc();
if (fp == NULL) {
printf("elf" __XSTRING(__ELF_WORD_SIZE) "_loadfile: cannot allocate module info\n");
err = EPERM;
goto out;
}
if (ef.kernel == 1 && multiboot == 0)
setenv("kernelname", filename, 1);
fp->f_name = strdup(filename);
if (multiboot == 0)
fp->f_type = strdup(ef.kernel ?
__elfN(kerneltype) : __elfN(moduletype));
else
fp->f_type = strdup("elf multiboot kernel");
#ifdef ELF_VERBOSE
if (ef.kernel)
printf("%s entry at 0x%jx\n", filename, (uintmax_t)ehdr->e_entry);
#else
printf("%s ", filename);
#endif
fp->f_size = __elfN(loadimage)(fp, &ef, dest);
if (fp->f_size == 0 || fp->f_addr == 0)
goto ioerr;
/* save exec header as metadata */
file_addmetadata(fp, MODINFOMD_ELFHDR, sizeof(*ehdr), ehdr);
/* Load OK, return module pointer */
*result = (struct preloaded_file *)fp;
err = 0;
goto out;
ioerr:
err = EIO;
oerr:
file_discard(fp);
out:
if (ef.firstpage)
free(ef.firstpage);
if (ef.fd != -1)
close(ef.fd);
return(err);
}
/*
* With the file (fd) open on the image, and (ehdr) containing
* the Elf header, load the image at (off)
*/
static int
__elfN(loadimage)(struct preloaded_file *fp, elf_file_t ef, u_int64_t off)
{
int i;
u_int j;
Elf_Ehdr *ehdr;
Elf_Phdr *phdr, *php;
Elf_Shdr *shdr;
char *shstr;
int ret;
vm_offset_t firstaddr;
vm_offset_t lastaddr;
size_t chunk;
ssize_t result;
Elf_Addr ssym, esym;
Elf_Dyn *dp;
Elf_Addr adp;
Elf_Addr ctors;
int ndp;
int symstrindex;
int symtabindex;
Elf_Size size;
u_int fpcopy;
Elf_Sym sym;
Elf_Addr p_start, p_end;
dp = NULL;
shdr = NULL;
ret = 0;
firstaddr = lastaddr = 0;
ehdr = ef->ehdr;
if (ehdr->e_type == ET_EXEC) {
#if defined(__i386__) || defined(__amd64__)
#if __ELF_WORD_SIZE == 64
off = - (off & 0xffffffffff000000ull);/* x86_64 relocates after locore */
#else
off = - (off & 0xff000000u); /* i386 relocates after locore */
#endif
#elif defined(__powerpc__)
/*
* On the purely virtual memory machines like e500, the kernel is
* linked against its final VA range, which is most often not
* available at the loader stage, but only after kernel initializes
* and completes its VM settings. In such cases we cannot use p_vaddr
* field directly to load ELF segments, but put them at some
* 'load-time' locations.
*/
if (off & 0xf0000000u) {
off = -(off & 0xf0000000u);
/*
* XXX the physical load address should not be hardcoded. Note
* that the Book-E kernel assumes that it's loaded at a 16MB
* boundary for now...
*/
off += 0x01000000;
ehdr->e_entry += off;
#ifdef ELF_VERBOSE
printf("Converted entry 0x%08x\n", ehdr->e_entry);
#endif
} else
off = 0;
#elif defined(__arm__) && !defined(EFI)
/*
* The elf headers in arm kernels specify virtual addresses in all
* header fields, even the ones that should be physical addresses.
* We assume the entry point is in the first page, and masking the page
* offset will leave us with the virtual address the kernel was linked
* at. We subtract that from the load offset, making 'off' into the
* value which, when added to a virtual address in an elf header,
* translates it to a physical address. We do the va->pa conversion on
* the entry point address in the header now, so that later we can
* launch the kernel by just jumping to that address.
*
* When booting from UEFI the copyin and copyout functions handle
* adjusting the location relative to the first virtual address.
* Because of this there is no need to adjust the offset or entry
* point address as these will both be handled by the efi code.
*/
off -= ehdr->e_entry & ~PAGE_MASK;
ehdr->e_entry += off;
#ifdef ELF_VERBOSE
printf("ehdr->e_entry 0x%08x, va<->pa off %llx\n", ehdr->e_entry, off);
#endif
#else
off = 0; /* other archs use direct mapped kernels */
#endif
}
ef->off = off;
if (ef->kernel)
__elfN(relocation_offset) = off;
if ((ehdr->e_phoff + ehdr->e_phnum * sizeof(*phdr)) > ef->firstlen) {
printf("elf" __XSTRING(__ELF_WORD_SIZE) "_loadimage: program header not within first page\n");
goto out;
}
phdr = (Elf_Phdr *)(ef->firstpage + ehdr->e_phoff);
for (i = 0; i < ehdr->e_phnum; i++) {
/* We want to load PT_LOAD segments only.. */
if (phdr[i].p_type != PT_LOAD)
continue;
#ifdef ELF_VERBOSE
printf("Segment: 0x%lx@0x%lx -> 0x%lx-0x%lx",
(long)phdr[i].p_filesz, (long)phdr[i].p_offset,
(long)(phdr[i].p_vaddr + off),
(long)(phdr[i].p_vaddr + off + phdr[i].p_memsz - 1));
#else
if ((phdr[i].p_flags & PF_W) == 0) {
printf("text=0x%lx ", (long)phdr[i].p_filesz);
} else {
printf("data=0x%lx", (long)phdr[i].p_filesz);
if (phdr[i].p_filesz < phdr[i].p_memsz)
printf("+0x%lx", (long)(phdr[i].p_memsz -phdr[i].p_filesz));
printf(" ");
}
#endif
fpcopy = 0;
if (ef->firstlen > phdr[i].p_offset) {
fpcopy = ef->firstlen - phdr[i].p_offset;
archsw.arch_copyin(ef->firstpage + phdr[i].p_offset,
phdr[i].p_vaddr + off, fpcopy);
}
if (phdr[i].p_filesz > fpcopy) {
if (kern_pread(ef->fd, phdr[i].p_vaddr + off + fpcopy,
phdr[i].p_filesz - fpcopy, phdr[i].p_offset + fpcopy) != 0) {
printf("\nelf" __XSTRING(__ELF_WORD_SIZE)
"_loadimage: read failed\n");
goto out;
}
}
/* clear space from oversized segments; eg: bss */
if (phdr[i].p_filesz < phdr[i].p_memsz) {
#ifdef ELF_VERBOSE
printf(" (bss: 0x%lx-0x%lx)",
(long)(phdr[i].p_vaddr + off + phdr[i].p_filesz),
(long)(phdr[i].p_vaddr + off + phdr[i].p_memsz - 1));
#endif
kern_bzero(phdr[i].p_vaddr + off + phdr[i].p_filesz,
phdr[i].p_memsz - phdr[i].p_filesz);
}
#ifdef ELF_VERBOSE
printf("\n");
#endif
if (archsw.arch_loadseg != NULL)
archsw.arch_loadseg(ehdr, phdr + i, off);
if (firstaddr == 0 || firstaddr > (phdr[i].p_vaddr + off))
firstaddr = phdr[i].p_vaddr + off;
if (lastaddr == 0 || lastaddr < (phdr[i].p_vaddr + off + phdr[i].p_memsz))
lastaddr = phdr[i].p_vaddr + off + phdr[i].p_memsz;
}
lastaddr = roundup(lastaddr, sizeof(long));
/*
* Get the section headers. We need this for finding the .ctors
* section as well as for loading any symbols. Both may be hard
* to do if reading from a .gz file as it involves seeking. I
* think the rule is going to have to be that you must strip a
* file to remove symbols before gzipping it.
*/
chunk = ehdr->e_shnum * ehdr->e_shentsize;
if (chunk == 0 || ehdr->e_shoff == 0)
goto nosyms;
shdr = alloc_pread(ef->fd, ehdr->e_shoff, chunk);
if (shdr == NULL) {
printf("\nelf" __XSTRING(__ELF_WORD_SIZE)
"_loadimage: failed to read section headers");
goto nosyms;
}
file_addmetadata(fp, MODINFOMD_SHDR, chunk, shdr);
/*
* Read the section string table and look for the .ctors section.
* We need to tell the kernel where it is so that it can call the
* ctors.
*/
chunk = shdr[ehdr->e_shstrndx].sh_size;
if (chunk) {
shstr = alloc_pread(ef->fd, shdr[ehdr->e_shstrndx].sh_offset, chunk);
if (shstr) {
for (i = 0; i < ehdr->e_shnum; i++) {
if (strcmp(shstr + shdr[i].sh_name, ".ctors") != 0)
continue;
ctors = shdr[i].sh_addr;
file_addmetadata(fp, MODINFOMD_CTORS_ADDR, sizeof(ctors),
&ctors);
size = shdr[i].sh_size;
file_addmetadata(fp, MODINFOMD_CTORS_SIZE, sizeof(size),
&size);
break;
}
free(shstr);
}
}
/*
* Now load any symbols.
*/
symtabindex = -1;
symstrindex = -1;
for (i = 0; i < ehdr->e_shnum; i++) {
if (shdr[i].sh_type != SHT_SYMTAB)
continue;
for (j = 0; j < ehdr->e_phnum; j++) {
if (phdr[j].p_type != PT_LOAD)
continue;
if (shdr[i].sh_offset >= phdr[j].p_offset &&
(shdr[i].sh_offset + shdr[i].sh_size <=
phdr[j].p_offset + phdr[j].p_filesz)) {
shdr[i].sh_offset = 0;
shdr[i].sh_size = 0;
break;
}
}
if (shdr[i].sh_offset == 0 || shdr[i].sh_size == 0)
continue; /* alread loaded in a PT_LOAD above */
/* Save it for loading below */
symtabindex = i;
symstrindex = shdr[i].sh_link;
}
if (symtabindex < 0 || symstrindex < 0)
goto nosyms;
/* Ok, committed to a load. */
#ifndef ELF_VERBOSE
printf("syms=[");
#endif
ssym = lastaddr;
for (i = symtabindex; i >= 0; i = symstrindex) {
#ifdef ELF_VERBOSE
char *secname;
switch(shdr[i].sh_type) {
case SHT_SYMTAB: /* Symbol table */
secname = "symtab";
break;
case SHT_STRTAB: /* String table */
secname = "strtab";
break;
default:
secname = "WHOA!!";
break;
}
#endif
size = shdr[i].sh_size;
archsw.arch_copyin(&size, lastaddr, sizeof(size));
lastaddr += sizeof(size);
#ifdef ELF_VERBOSE
printf("\n%s: 0x%jx@0x%jx -> 0x%jx-0x%jx", secname,
(uintmax_t)shdr[i].sh_size, (uintmax_t)shdr[i].sh_offset,
(uintmax_t)lastaddr, (uintmax_t)(lastaddr + shdr[i].sh_size));
#else
if (i == symstrindex)
printf("+");
printf("0x%lx+0x%lx", (long)sizeof(size), (long)size);
#endif
if (lseek(ef->fd, (off_t)shdr[i].sh_offset, SEEK_SET) == -1) {
printf("\nelf" __XSTRING(__ELF_WORD_SIZE) "_loadimage: could not seek for symbols - skipped!");
lastaddr = ssym;
ssym = 0;
goto nosyms;
}
result = archsw.arch_readin(ef->fd, lastaddr, shdr[i].sh_size);
if (result < 0 || (size_t)result != shdr[i].sh_size) {
printf("\nelf" __XSTRING(__ELF_WORD_SIZE) "_loadimage: could not read symbols - skipped! (%ju != %ju)", (uintmax_t)result,
(uintmax_t)shdr[i].sh_size);
lastaddr = ssym;
ssym = 0;
goto nosyms;
}
/* Reset offsets relative to ssym */
lastaddr += shdr[i].sh_size;
lastaddr = roundup(lastaddr, sizeof(size));
if (i == symtabindex)
symtabindex = -1;
else if (i == symstrindex)
symstrindex = -1;
}
esym = lastaddr;
#ifndef ELF_VERBOSE
printf("]");
#endif
file_addmetadata(fp, MODINFOMD_SSYM, sizeof(ssym), &ssym);
file_addmetadata(fp, MODINFOMD_ESYM, sizeof(esym), &esym);
nosyms:
printf("\n");
ret = lastaddr - firstaddr;
fp->f_addr = firstaddr;
php = NULL;
for (i = 0; i < ehdr->e_phnum; i++) {
if (phdr[i].p_type == PT_DYNAMIC) {
php = phdr + i;
adp = php->p_vaddr;
file_addmetadata(fp, MODINFOMD_DYNAMIC, sizeof(adp), &adp);
break;
}
}
if (php == NULL) /* this is bad, we cannot get to symbols or _DYNAMIC */
goto out;
ndp = php->p_filesz / sizeof(Elf_Dyn);
if (ndp == 0)
goto out;
dp = malloc(php->p_filesz);
if (dp == NULL)
goto out;
archsw.arch_copyout(php->p_vaddr + off, dp, php->p_filesz);
ef->strsz = 0;
for (i = 0; i < ndp; i++) {
if (dp[i].d_tag == 0)
break;
switch (dp[i].d_tag) {
case DT_HASH:
ef->hashtab = (Elf_Hashelt*)(uintptr_t)(dp[i].d_un.d_ptr + off);
break;
case DT_STRTAB:
ef->strtab = (char *)(uintptr_t)(dp[i].d_un.d_ptr + off);
break;
case DT_STRSZ:
ef->strsz = dp[i].d_un.d_val;
break;
case DT_SYMTAB:
ef->symtab = (Elf_Sym*)(uintptr_t)(dp[i].d_un.d_ptr + off);
break;
case DT_REL:
ef->rel = (Elf_Rel *)(uintptr_t)(dp[i].d_un.d_ptr + off);
break;
case DT_RELSZ:
ef->relsz = dp[i].d_un.d_val;
break;
case DT_RELA:
ef->rela = (Elf_Rela *)(uintptr_t)(dp[i].d_un.d_ptr + off);
break;
case DT_RELASZ:
ef->relasz = dp[i].d_un.d_val;
break;
default:
break;
}
}
if (ef->hashtab == NULL || ef->symtab == NULL ||
ef->strtab == NULL || ef->strsz == 0)
goto out;
COPYOUT(ef->hashtab, &ef->nbuckets, sizeof(ef->nbuckets));
COPYOUT(ef->hashtab + 1, &ef->nchains, sizeof(ef->nchains));
ef->buckets = ef->hashtab + 2;
ef->chains = ef->buckets + ef->nbuckets;
if (__elfN(lookup_symbol)(fp, ef, "__start_set_modmetadata_set", &sym) != 0)
return 0;
p_start = sym.st_value + ef->off;
if (__elfN(lookup_symbol)(fp, ef, "__stop_set_modmetadata_set", &sym) != 0)
return ENOENT;
p_end = sym.st_value + ef->off;
if (__elfN(parse_modmetadata)(fp, ef, p_start, p_end) == 0)
goto out;
if (ef->kernel) /* kernel must not depend on anything */
goto out;
out:
if (dp)
free(dp);
if (shdr)
free(shdr);
return ret;
}
static char invalid_name[] = "bad";
char *
fake_modname(const char *name)
{
const char *sp, *ep;
char *fp;
size_t len;
sp = strrchr(name, '/');
if (sp)
sp++;
else
sp = name;
ep = strrchr(name, '.');
if (ep) {
if (ep == name) {
sp = invalid_name;
ep = invalid_name + sizeof(invalid_name) - 1;
}
} else
ep = name + strlen(name);
len = ep - sp;
fp = malloc(len + 1);
if (fp == NULL)
return NULL;
memcpy(fp, sp, len);
fp[len] = '\0';
return fp;
}
#if (defined(__i386__) || defined(__powerpc__)) && __ELF_WORD_SIZE == 64
struct mod_metadata64 {
int md_version; /* structure version MDTV_* */
int md_type; /* type of entry MDT_* */
u_int64_t md_data; /* specific data */
u_int64_t md_cval; /* common string label */
};
#endif
#if defined(__amd64__) && __ELF_WORD_SIZE == 32
struct mod_metadata32 {
int md_version; /* structure version MDTV_* */
int md_type; /* type of entry MDT_* */
u_int32_t md_data; /* specific data */
u_int32_t md_cval; /* common string label */
};
#endif
int
__elfN(load_modmetadata)(struct preloaded_file *fp, u_int64_t dest)
{
struct elf_file ef;
int err, i, j;
Elf_Shdr *sh_meta, *shdr = NULL;
Elf_Shdr *sh_data[2];
char *shstrtab = NULL;
size_t size;
Elf_Addr p_start, p_end;
bzero(&ef, sizeof(struct elf_file));
ef.fd = -1;
err = __elfN(load_elf_header)(fp->f_name, &ef);
if (err != 0)
goto out;
if (ef.kernel == 1 || ef.ehdr->e_type == ET_EXEC) {
ef.kernel = 1;
} else if (ef.ehdr->e_type != ET_DYN) {
err = EFTYPE;
goto out;
}
size = ef.ehdr->e_shnum * ef.ehdr->e_shentsize;
shdr = alloc_pread(ef.fd, ef.ehdr->e_shoff, size);
if (shdr == NULL) {
err = ENOMEM;
goto out;
}
/* Load shstrtab. */
shstrtab = alloc_pread(ef.fd, shdr[ef.ehdr->e_shstrndx].sh_offset,
shdr[ef.ehdr->e_shstrndx].sh_size);
if (shstrtab == NULL) {
printf("\nelf" __XSTRING(__ELF_WORD_SIZE)
"load_modmetadata: unable to load shstrtab\n");
err = EFTYPE;
goto out;
}
/* Find set_modmetadata_set and data sections. */
sh_data[0] = sh_data[1] = sh_meta = NULL;
for (i = 0, j = 0; i < ef.ehdr->e_shnum; i++) {
if (strcmp(&shstrtab[shdr[i].sh_name],
"set_modmetadata_set") == 0) {
sh_meta = &shdr[i];
}
if ((strcmp(&shstrtab[shdr[i].sh_name], ".data") == 0) ||
(strcmp(&shstrtab[shdr[i].sh_name], ".rodata") == 0)) {
sh_data[j++] = &shdr[i];
}
}
if (sh_meta == NULL || sh_data[0] == NULL || sh_data[1] == NULL) {
printf("\nelf" __XSTRING(__ELF_WORD_SIZE)
"load_modmetadata: unable to find set_modmetadata_set or data sections\n");
err = EFTYPE;
goto out;
}
/* Load set_modmetadata_set into memory */
err = kern_pread(ef.fd, dest, sh_meta->sh_size, sh_meta->sh_offset);
if (err != 0) {
printf("\nelf" __XSTRING(__ELF_WORD_SIZE)
"load_modmetadata: unable to load set_modmetadata_set: %d\n", err);
goto out;
}
p_start = dest;
p_end = dest + sh_meta->sh_size;
dest += sh_meta->sh_size;
/* Load data sections into memory. */
err = kern_pread(ef.fd, dest, sh_data[0]->sh_size,
sh_data[0]->sh_offset);
if (err != 0) {
printf("\nelf" __XSTRING(__ELF_WORD_SIZE)
"load_modmetadata: unable to load data: %d\n", err);
goto out;
}
/*
* We have to increment the dest, so that the offset is the same into
* both the .rodata and .data sections.
*/
ef.off = -(sh_data[0]->sh_addr - dest);
dest += (sh_data[1]->sh_addr - sh_data[0]->sh_addr);
err = kern_pread(ef.fd, dest, sh_data[1]->sh_size,
sh_data[1]->sh_offset);
if (err != 0) {
printf("\nelf" __XSTRING(__ELF_WORD_SIZE)
"load_modmetadata: unable to load data: %d\n", err);
goto out;
}
err = __elfN(parse_modmetadata)(fp, &ef, p_start, p_end);
if (err != 0) {
printf("\nelf" __XSTRING(__ELF_WORD_SIZE)
"load_modmetadata: unable to parse metadata: %d\n", err);
goto out;
}
out:
if (shstrtab != NULL)
free(shstrtab);
if (shdr != NULL)
free(shdr);
if (ef.firstpage != NULL)
free(ef.firstpage);
if (ef.fd != -1)
close(ef.fd);
return (err);
}
int
__elfN(parse_modmetadata)(struct preloaded_file *fp, elf_file_t ef,
Elf_Addr p_start, Elf_Addr p_end)
{
struct mod_metadata md;
#if (defined(__i386__) || defined(__powerpc__)) && __ELF_WORD_SIZE == 64
struct mod_metadata64 md64;
#elif defined(__amd64__) && __ELF_WORD_SIZE == 32
struct mod_metadata32 md32;
#endif
struct mod_depend *mdepend;
struct mod_version mver;
char *s;
int error, modcnt, minfolen;
Elf_Addr v, p;
modcnt = 0;
p = p_start;
while (p < p_end) {
COPYOUT(p, &v, sizeof(v));
error = __elfN(reloc_ptr)(fp, ef, p, &v, sizeof(v));
if (error == EOPNOTSUPP)
v += ef->off;
else if (error != 0)
return (error);
#if (defined(__i386__) || defined(__powerpc__)) && __ELF_WORD_SIZE == 64
COPYOUT(v, &md64, sizeof(md64));
error = __elfN(reloc_ptr)(fp, ef, v, &md64, sizeof(md64));
if (error == EOPNOTSUPP) {
md64.md_cval += ef->off;
md64.md_data += ef->off;
} else if (error != 0)
return (error);
md.md_version = md64.md_version;
md.md_type = md64.md_type;
md.md_cval = (const char *)(uintptr_t)md64.md_cval;
md.md_data = (void *)(uintptr_t)md64.md_data;
#elif defined(__amd64__) && __ELF_WORD_SIZE == 32
COPYOUT(v, &md32, sizeof(md32));
error = __elfN(reloc_ptr)(fp, ef, v, &md32, sizeof(md32));
if (error == EOPNOTSUPP) {
md32.md_cval += ef->off;
md32.md_data += ef->off;
} else if (error != 0)
return (error);
md.md_version = md32.md_version;
md.md_type = md32.md_type;
md.md_cval = (const char *)(uintptr_t)md32.md_cval;
md.md_data = (void *)(uintptr_t)md32.md_data;
#else
COPYOUT(v, &md, sizeof(md));
error = __elfN(reloc_ptr)(fp, ef, v, &md, sizeof(md));
if (error == EOPNOTSUPP) {
md.md_cval += ef->off;
md.md_data = (void *)((uintptr_t)md.md_data + (uintptr_t)ef->off);
} else if (error != 0)
return (error);
#endif
p += sizeof(Elf_Addr);
switch(md.md_type) {
case MDT_DEPEND:
if (ef->kernel) /* kernel must not depend on anything */
break;
s = strdupout((vm_offset_t)md.md_cval);
minfolen = sizeof(*mdepend) + strlen(s) + 1;
mdepend = malloc(minfolen);
if (mdepend == NULL)
return ENOMEM;
COPYOUT((vm_offset_t)md.md_data, mdepend, sizeof(*mdepend));
strcpy((char*)(mdepend + 1), s);
free(s);
file_addmetadata(fp, MODINFOMD_DEPLIST, minfolen, mdepend);
free(mdepend);
break;
case MDT_VERSION:
s = strdupout((vm_offset_t)md.md_cval);
COPYOUT((vm_offset_t)md.md_data, &mver, sizeof(mver));
file_addmodule(fp, s, mver.mv_version, NULL);
free(s);
modcnt++;
break;
}
}
if (modcnt == 0) {
s = fake_modname(fp->f_name);
file_addmodule(fp, s, 1, NULL);
free(s);
}
return 0;
}
static unsigned long
elf_hash(const char *name)
{
const unsigned char *p = (const unsigned char *) name;
unsigned long h = 0;
unsigned long g;
while (*p != '\0') {
h = (h << 4) + *p++;
if ((g = h & 0xf0000000) != 0)
h ^= g >> 24;
h &= ~g;
}
return h;
}
static const char __elfN(bad_symtable)[] = "elf" __XSTRING(__ELF_WORD_SIZE) "_lookup_symbol: corrupt symbol table\n";
int
__elfN(lookup_symbol)(struct preloaded_file *fp, elf_file_t ef, const char* name,
Elf_Sym *symp)
{
Elf_Hashelt symnum;
Elf_Sym sym;
char *strp;
unsigned long hash;
hash = elf_hash(name);
COPYOUT(&ef->buckets[hash % ef->nbuckets], &symnum, sizeof(symnum));
while (symnum != STN_UNDEF) {
if (symnum >= ef->nchains) {
printf(__elfN(bad_symtable));
return ENOENT;
}
COPYOUT(ef->symtab + symnum, &sym, sizeof(sym));
if (sym.st_name == 0) {
printf(__elfN(bad_symtable));
return ENOENT;
}
strp = strdupout((vm_offset_t)(ef->strtab + sym.st_name));
if (strcmp(name, strp) == 0) {
free(strp);
if (sym.st_shndx != SHN_UNDEF ||
(sym.st_value != 0 &&
ELF_ST_TYPE(sym.st_info) == STT_FUNC)) {
*symp = sym;
return 0;
}
return ENOENT;
}
free(strp);
COPYOUT(&ef->chains[symnum], &symnum, sizeof(symnum));
}
return ENOENT;
}
/*
* Apply any intra-module relocations to the value. p is the load address
* of the value and val/len is the value to be modified. This does NOT modify
* the image in-place, because this is done by kern_linker later on.
*
* Returns EOPNOTSUPP if no relocation method is supplied.
*/
static int
__elfN(reloc_ptr)(struct preloaded_file *mp, elf_file_t ef,
Elf_Addr p, void *val, size_t len)
{
size_t n;
Elf_Rela a;
Elf_Rel r;
int error;
/*
* The kernel is already relocated, but we still want to apply
* offset adjustments.
*/
if (ef->kernel)
return (EOPNOTSUPP);
for (n = 0; n < ef->relsz / sizeof(r); n++) {
COPYOUT(ef->rel + n, &r, sizeof(r));
error = __elfN(reloc)(ef, __elfN(symaddr), &r, ELF_RELOC_REL,
ef->off, p, val, len);
if (error != 0)
return (error);
}
for (n = 0; n < ef->relasz / sizeof(a); n++) {
COPYOUT(ef->rela + n, &a, sizeof(a));
error = __elfN(reloc)(ef, __elfN(symaddr), &a, ELF_RELOC_RELA,
ef->off, p, val, len);
if (error != 0)
return (error);
}
return (0);
}
static Elf_Addr
__elfN(symaddr)(struct elf_file *ef, Elf_Size symidx)
{
/* Symbol lookup by index not required here. */
return (0);
}
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