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3ef693a032
qemu/linux-user/elfload.c
bellard 3ef693a032 distribution patches 
git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@44 c046a42c-6fe2-441c-8c8c-71466251a162
2003-03-23 20:17:16 +00:00

977 lines
26 KiB
C
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/* This is the Linux kernel elf-loading code, ported into user space */
#include <stdio.h>
#include <sys/types.h>
#include <fcntl.h>
#include <sys/stat.h>
#include <errno.h>
#include <unistd.h>
#include <sys/mman.h>
#include <stdlib.h>
#include <string.h>
#include "qemu.h"
#include "linux_bin.h"
#include "elf.h"
#include "segment.h"
/* Necessary parameters */
#define ALPHA_PAGE_SIZE 4096
#define X86_PAGE_SIZE 4096
#define ALPHA_PAGE_MASK (~(ALPHA_PAGE_SIZE-1))
#define X86_PAGE_MASK (~(X86_PAGE_SIZE-1))
#define ALPHA_PAGE_ALIGN(addr) ((((addr)+ALPHA_PAGE_SIZE)-1)&ALPHA_PAGE_MASK)
#define X86_PAGE_ALIGN(addr) ((((addr)+X86_PAGE_SIZE)-1)&X86_PAGE_MASK)
#define NGROUPS 32
#define X86_ELF_EXEC_PAGESIZE X86_PAGE_SIZE
#define X86_ELF_PAGESTART(_v) ((_v) & ~(unsigned long)(X86_ELF_EXEC_PAGESIZE-1))
#define X86_ELF_PAGEOFFSET(_v) ((_v) & (X86_ELF_EXEC_PAGESIZE-1))
#define ALPHA_ELF_PAGESTART(_v) ((_v) & ~(unsigned long)(ALPHA_PAGE_SIZE-1))
#define ALPHA_ELF_PAGEOFFSET(_v) ((_v) & (ALPHA_PAGE_SIZE-1))
#define INTERPRETER_NONE 0
#define INTERPRETER_AOUT 1
#define INTERPRETER_ELF 2
#define DLINFO_ITEMS 12
/* Where we find X86 libraries... */
//#define X86_DEFAULT_LIB_DIR "/usr/x86/"
#define X86_DEFAULT_LIB_DIR "/"
//extern void * mmap4k();
#define mmap4k(a, b, c, d, e, f) mmap((void *)(a), b, c, d, e, f)
extern unsigned long x86_stack_size;
static int load_aout_interp(void * exptr, int interp_fd);
#ifdef BSWAP_NEEDED
static void bswap_ehdr(Elf32_Ehdr *ehdr)
{
bswap16s(&ehdr->e_type); /* Object file type */
bswap16s(&ehdr->e_machine); /* Architecture */
bswap32s(&ehdr->e_version); /* Object file version */
bswap32s(&ehdr->e_entry); /* Entry point virtual address */
bswap32s(&ehdr->e_phoff); /* Program header table file offset */
bswap32s(&ehdr->e_shoff); /* Section header table file offset */
bswap32s(&ehdr->e_flags); /* Processor-specific flags */
bswap16s(&ehdr->e_ehsize); /* ELF header size in bytes */
bswap16s(&ehdr->e_phentsize); /* Program header table entry size */
bswap16s(&ehdr->e_phnum); /* Program header table entry count */
bswap16s(&ehdr->e_shentsize); /* Section header table entry size */
bswap16s(&ehdr->e_shnum); /* Section header table entry count */
bswap16s(&ehdr->e_shstrndx); /* Section header string table index */
}
static void bswap_phdr(Elf32_Phdr *phdr)
{
bswap32s(&phdr->p_type); /* Segment type */
bswap32s(&phdr->p_offset); /* Segment file offset */
bswap32s(&phdr->p_vaddr); /* Segment virtual address */
bswap32s(&phdr->p_paddr); /* Segment physical address */
bswap32s(&phdr->p_filesz); /* Segment size in file */
bswap32s(&phdr->p_memsz); /* Segment size in memory */
bswap32s(&phdr->p_flags); /* Segment flags */
bswap32s(&phdr->p_align); /* Segment alignment */
}
#endif
static void * get_free_page(void)
{
void * retval;
/* User-space version of kernel get_free_page. Returns a page-aligned
* page-sized chunk of memory.
*/
retval = mmap4k(0, ALPHA_PAGE_SIZE, PROT_READ|PROT_WRITE,
MAP_PRIVATE|MAP_ANONYMOUS, -1, 0);
if((long)retval == -1) {
perror("get_free_page");
exit(-1);
}
else {
return(retval);
}
}
static void free_page(void * pageaddr)
{
(void)munmap(pageaddr, ALPHA_PAGE_SIZE);
}
/*
* 'copy_string()' copies argument/envelope strings from user
* memory to free pages in kernel mem. These are in a format ready
* to be put directly into the top of new user memory.
*
*/
static unsigned long copy_strings(int argc,char ** argv,unsigned long *page,
unsigned long p)
{
char *tmp, *tmp1, *pag = NULL;
int len, offset = 0;
if (!p) {
return 0; /* bullet-proofing */
}
while (argc-- > 0) {
if (!(tmp1 = tmp = get_user(argv+argc))) {
fprintf(stderr, "VFS: argc is wrong");
exit(-1);
}
while (get_user(tmp++));
len = tmp - tmp1;
if (p < len) { /* this shouldn't happen - 128kB */
return 0;
}
while (len) {
--p; --tmp; --len;
if (--offset < 0) {
offset = p % X86_PAGE_SIZE;
if (!(pag = (char *) page[p/X86_PAGE_SIZE]) &&
!(pag = (char *) page[p/X86_PAGE_SIZE] =
(unsigned long *) get_free_page())) {
return 0;
}
}
if (len == 0 || offset == 0) {
*(pag + offset) = get_user(tmp);
}
else {
int bytes_to_copy = (len > offset) ? offset : len;
tmp -= bytes_to_copy;
p -= bytes_to_copy;
offset -= bytes_to_copy;
len -= bytes_to_copy;
memcpy_fromfs(pag + offset, tmp, bytes_to_copy + 1);
}
}
}
return p;
}
static int in_group_p(gid_t g)
{
/* return TRUE if we're in the specified group, FALSE otherwise */
int ngroup;
int i;
gid_t grouplist[NGROUPS];
ngroup = getgroups(NGROUPS, grouplist);
for(i = 0; i < ngroup; i++) {
if(grouplist[i] == g) {
return 1;
}
}
return 0;
}
static int count(char ** vec)
{
int i;
for(i = 0; *vec; i++) {
vec++;
}
return(i);
}
static int prepare_binprm(struct linux_binprm *bprm)
{
struct stat st;
int mode;
int retval, id_change;
if(fstat(bprm->fd, &st) < 0) {
return(-errno);
}
mode = st.st_mode;
if(!S_ISREG(mode)) { /* Must be regular file */
return(-EACCES);
}
if(!(mode & 0111)) { /* Must have at least one execute bit set */
return(-EACCES);
}
bprm->e_uid = geteuid();
bprm->e_gid = getegid();
id_change = 0;
/* Set-uid? */
if(mode & S_ISUID) {
bprm->e_uid = st.st_uid;
if(bprm->e_uid != geteuid()) {
id_change = 1;
}
}
/* Set-gid? */
/*
* If setgid is set but no group execute bit then this
* is a candidate for mandatory locking, not a setgid
* executable.
*/
if ((mode & (S_ISGID | S_IXGRP)) == (S_ISGID | S_IXGRP)) {
bprm->e_gid = st.st_gid;
if (!in_group_p(bprm->e_gid)) {
id_change = 1;
}
}
memset(bprm->buf, 0, sizeof(bprm->buf));
retval = lseek(bprm->fd, 0L, SEEK_SET);
if(retval >= 0) {
retval = read(bprm->fd, bprm->buf, 128);
}
if(retval < 0) {
perror("prepare_binprm");
exit(-1);
/* return(-errno); */
}
else {
return(retval);
}
}
unsigned long setup_arg_pages(unsigned long p, struct linux_binprm * bprm,
struct image_info * info)
{
unsigned long stack_base;
int i;
extern unsigned long stktop;
stack_base = X86_STACK_TOP - MAX_ARG_PAGES*X86_PAGE_SIZE;
p += stack_base;
if (bprm->loader) {
bprm->loader += stack_base;
}
bprm->exec += stack_base;
/* Create enough stack to hold everything. If we don't use
* it for args, we'll use it for something else...
*/
/* XXX: on x86 MAP_GROWSDOWN only works if ESP <= address + 32, so
we allocate a bigger stack. Need a better solution, for example
by remapping the process stack directly at the right place */
if(x86_stack_size > MAX_ARG_PAGES*X86_PAGE_SIZE) {
if((long)mmap4k((void *)(X86_STACK_TOP-x86_stack_size), x86_stack_size + X86_PAGE_SIZE,
PROT_READ | PROT_WRITE,
MAP_GROWSDOWN | MAP_FIXED | MAP_PRIVATE | MAP_ANONYMOUS, -1, 0) == -1) {
perror("stk mmap");
exit(-1);
}
}
else {
if((long)mmap4k((void *)stack_base, (MAX_ARG_PAGES+1)*X86_PAGE_SIZE,
PROT_READ | PROT_WRITE,
MAP_GROWSDOWN | MAP_FIXED | MAP_PRIVATE | MAP_ANONYMOUS, -1, 0) == -1) {
perror("stk mmap");
exit(-1);
}
}
stktop = stack_base;
for (i = 0 ; i < MAX_ARG_PAGES ; i++) {
if (bprm->page[i]) {
info->rss++;
memcpy((void *)stack_base, (void *)bprm->page[i], X86_PAGE_SIZE);
free_page((void *)bprm->page[i]);
}
stack_base += X86_PAGE_SIZE;
}
return p;
}
static void set_brk(unsigned long start, unsigned long end)
{
/* page-align the start and end addresses... */
start = ALPHA_PAGE_ALIGN(start);
end = ALPHA_PAGE_ALIGN(end);
if (end <= start)
return;
if((long)mmap4k(start, end - start,
PROT_READ | PROT_WRITE | PROT_EXEC,
MAP_FIXED | MAP_PRIVATE | MAP_ANONYMOUS, -1, 0) == -1) {
perror("cannot mmap brk");
exit(-1);
}
}
/* We need to explicitly zero any fractional pages
after the data section (i.e. bss). This would
contain the junk from the file that should not
be in memory */
static void padzero(unsigned long elf_bss)
{
unsigned long nbyte;
char * fpnt;
nbyte = elf_bss & (ALPHA_PAGE_SIZE-1); /* was X86_PAGE_SIZE - JRP */
if (nbyte) {
nbyte = ALPHA_PAGE_SIZE - nbyte;
fpnt = (char *) elf_bss;
do {
*fpnt++ = 0;
} while (--nbyte);
}
}
static unsigned int * create_elf_tables(char *p, int argc, int envc,
struct elfhdr * exec,
unsigned long load_addr,
unsigned long interp_load_addr, int ibcs,
struct image_info *info)
{
target_ulong *argv, *envp, *dlinfo;
target_ulong *sp;
/*
* Force 16 byte alignment here for generality.
*/
sp = (unsigned int *) (~15UL & (unsigned long) p);
sp -= exec ? DLINFO_ITEMS*2 : 2;
dlinfo = sp;
sp -= envc+1;
envp = sp;
sp -= argc+1;
argv = sp;
if (!ibcs) {
put_user(tswapl((target_ulong)envp),--sp);
put_user(tswapl((target_ulong)argv),--sp);
}
#define NEW_AUX_ENT(id, val) \
put_user (tswapl(id), dlinfo++); \
put_user (tswapl(val), dlinfo++)
if (exec) { /* Put this here for an ELF program interpreter */
struct elf_phdr * eppnt;
eppnt = (struct elf_phdr *)((unsigned long)exec->e_phoff);
NEW_AUX_ENT (AT_PHDR, (unsigned int)(load_addr + exec->e_phoff));
NEW_AUX_ENT (AT_PHENT, (unsigned int)(sizeof (struct elf_phdr)));
NEW_AUX_ENT (AT_PHNUM, (unsigned int)(exec->e_phnum));
NEW_AUX_ENT (AT_PAGESZ, (unsigned int)(ALPHA_PAGE_SIZE));
NEW_AUX_ENT (AT_BASE, (unsigned int)(interp_load_addr));
NEW_AUX_ENT (AT_FLAGS, (unsigned int)0);
NEW_AUX_ENT (AT_ENTRY, (unsigned int) exec->e_entry);
NEW_AUX_ENT (AT_UID, (unsigned int) getuid());
NEW_AUX_ENT (AT_EUID, (unsigned int) geteuid());
NEW_AUX_ENT (AT_GID, (unsigned int) getgid());
NEW_AUX_ENT (AT_EGID, (unsigned int) getegid());
}
NEW_AUX_ENT (AT_NULL, 0);
#undef NEW_AUX_ENT
put_user(tswapl(argc),--sp);
info->arg_start = (unsigned int)((unsigned long)p & 0xffffffff);
while (argc-->0) {
put_user(tswapl((target_ulong)p),argv++);
while (get_user(p++)) /* nothing */ ;
}
put_user(0,argv);
info->arg_end = info->env_start = (unsigned int)((unsigned long)p & 0xffffffff);
while (envc-->0) {
put_user(tswapl((target_ulong)p),envp++);
while (get_user(p++)) /* nothing */ ;
}
put_user(0,envp);
info->env_end = (unsigned int)((unsigned long)p & 0xffffffff);
return sp;
}
static unsigned long load_elf_interp(struct elfhdr * interp_elf_ex,
int interpreter_fd,
unsigned long *interp_load_addr)
{
struct elf_phdr *elf_phdata = NULL;
struct elf_phdr *eppnt;
unsigned long load_addr;
int load_addr_set = 0;
int retval;
unsigned long last_bss, elf_bss;
unsigned long error;
int i;
elf_bss = 0;
last_bss = 0;
error = 0;
/* We put this here so that mmap will search for the *first*
* available memory...
*/
load_addr = INTERP_LOADADDR;
/* First of all, some simple consistency checks */
if ((interp_elf_ex->e_type != ET_EXEC &&
interp_elf_ex->e_type != ET_DYN) ||
!elf_check_arch(interp_elf_ex->e_machine)) {
return ~0UL;
}
/* Now read in all of the header information */
if (sizeof(struct elf_phdr) * interp_elf_ex->e_phnum > X86_PAGE_SIZE)
return ~0UL;
elf_phdata = (struct elf_phdr *)
malloc(sizeof(struct elf_phdr) * interp_elf_ex->e_phnum);
if (!elf_phdata)
return ~0UL;
/*
* If the size of this structure has changed, then punt, since
* we will be doing the wrong thing.
*/
if (interp_elf_ex->e_phentsize != sizeof(struct elf_phdr))
{
free(elf_phdata);
return ~0UL;
}
retval = lseek(interpreter_fd, interp_elf_ex->e_phoff, SEEK_SET);
if(retval >= 0) {
retval = read(interpreter_fd,
(char *) elf_phdata,
sizeof(struct elf_phdr) * interp_elf_ex->e_phnum);
}
if (retval < 0) {
perror("load_elf_interp");
exit(-1);
free (elf_phdata);
return retval;
}
#ifdef BSWAP_NEEDED
eppnt = elf_phdata;
for (i=0; i<interp_elf_ex->e_phnum; i++, eppnt++) {
bswap_phdr(eppnt);
}
#endif
eppnt = elf_phdata;
for(i=0; i<interp_elf_ex->e_phnum; i++, eppnt++)
if (eppnt->p_type == PT_LOAD) {
int elf_type = MAP_PRIVATE | MAP_DENYWRITE;
int elf_prot = 0;
unsigned long vaddr = 0;
unsigned long k;
if (eppnt->p_flags & PF_R) elf_prot = PROT_READ;
if (eppnt->p_flags & PF_W) elf_prot |= PROT_WRITE;
if (eppnt->p_flags & PF_X) elf_prot |= PROT_EXEC;
if (interp_elf_ex->e_type == ET_EXEC || load_addr_set) {
elf_type |= MAP_FIXED;
vaddr = eppnt->p_vaddr;
}
error = (unsigned long)mmap4k(load_addr+X86_ELF_PAGESTART(vaddr),
eppnt->p_filesz + X86_ELF_PAGEOFFSET(eppnt->p_vaddr),
elf_prot,
elf_type,
interpreter_fd,
eppnt->p_offset - X86_ELF_PAGEOFFSET(eppnt->p_vaddr));
if (error > -1024UL) {
/* Real error */
close(interpreter_fd);
free(elf_phdata);
return ~0UL;
}
if (!load_addr_set && interp_elf_ex->e_type == ET_DYN) {
load_addr = error;
load_addr_set = 1;
}
/*
* Find the end of the file mapping for this phdr, and keep
* track of the largest address we see for this.
*/
k = load_addr + eppnt->p_vaddr + eppnt->p_filesz;
if (k > elf_bss) elf_bss = k;
/*
* Do the same thing for the memory mapping - between
* elf_bss and last_bss is the bss section.
*/
k = load_addr + eppnt->p_memsz + eppnt->p_vaddr;
if (k > last_bss) last_bss = k;
}
/* Now use mmap to map the library into memory. */
close(interpreter_fd);
/*
* Now fill out the bss section. First pad the last page up
* to the page boundary, and then perform a mmap to make sure
* that there are zeromapped pages up to and including the last
* bss page.
*/
padzero(elf_bss);
elf_bss = X86_ELF_PAGESTART(elf_bss + ALPHA_PAGE_SIZE - 1); /* What we have mapped so far */
/* Map the last of the bss segment */
if (last_bss > elf_bss) {
mmap4k(elf_bss, last_bss-elf_bss,
PROT_READ|PROT_WRITE|PROT_EXEC,
MAP_FIXED|MAP_PRIVATE|MAP_ANONYMOUS, -1, 0);
}
free(elf_phdata);
*interp_load_addr = load_addr;
return ((unsigned long) interp_elf_ex->e_entry) + load_addr;
}
static int load_elf_binary(struct linux_binprm * bprm, struct target_pt_regs * regs,
struct image_info * info)
{
struct elfhdr elf_ex;
struct elfhdr interp_elf_ex;
struct exec interp_ex;
int interpreter_fd = -1; /* avoid warning */
unsigned long load_addr;
int load_addr_set = 0;
unsigned int interpreter_type = INTERPRETER_NONE;
unsigned char ibcs2_interpreter;
int i;
void * mapped_addr;
struct elf_phdr * elf_ppnt;
struct elf_phdr *elf_phdata;
unsigned long elf_bss, k, elf_brk;
int retval;
char * elf_interpreter;
unsigned long elf_entry, interp_load_addr = 0;
int status;
unsigned long start_code, end_code, end_data;
unsigned long elf_stack;
char passed_fileno[6];
ibcs2_interpreter = 0;
status = 0;
load_addr = 0;
elf_ex = *((struct elfhdr *) bprm->buf); /* exec-header */
#ifdef BSWAP_NEEDED
bswap_ehdr(&elf_ex);
#endif
if (elf_ex.e_ident[0] != 0x7f ||
strncmp(&elf_ex.e_ident[1], "ELF",3) != 0) {
return -ENOEXEC;
}
/* First of all, some simple consistency checks */
if ((elf_ex.e_type != ET_EXEC && elf_ex.e_type != ET_DYN) ||
(! elf_check_arch(elf_ex.e_machine))) {
return -ENOEXEC;
}
/* Now read in all of the header information */
elf_phdata = (struct elf_phdr *)malloc(elf_ex.e_phentsize*elf_ex.e_phnum);
if (elf_phdata == NULL) {
return -ENOMEM;
}
retval = lseek(bprm->fd, elf_ex.e_phoff, SEEK_SET);
if(retval > 0) {
retval = read(bprm->fd, (char *) elf_phdata,
elf_ex.e_phentsize * elf_ex.e_phnum);
}
if (retval < 0) {
perror("load_elf_binary");
exit(-1);
free (elf_phdata);
return -errno;
}
#ifdef BSWAP_NEEDED
elf_ppnt = elf_phdata;
for (i=0; i<elf_ex.e_phnum; i++, elf_ppnt++) {
bswap_phdr(elf_ppnt);
}
#endif
elf_ppnt = elf_phdata;
elf_bss = 0;
elf_brk = 0;
elf_stack = ~0UL;
elf_interpreter = NULL;
start_code = ~0UL;
end_code = 0;
end_data = 0;
for(i=0;i < elf_ex.e_phnum; i++) {
if (elf_ppnt->p_type == PT_INTERP) {
if ( elf_interpreter != NULL )
{
free (elf_phdata);
free(elf_interpreter);
close(bprm->fd);
return -EINVAL;
}
/* This is the program interpreter used for
* shared libraries - for now assume that this
* is an a.out format binary
*/
elf_interpreter = (char *)malloc(elf_ppnt->p_filesz+strlen(X86_DEFAULT_LIB_DIR));
if (elf_interpreter == NULL) {
free (elf_phdata);
close(bprm->fd);
return -ENOMEM;
}
strcpy(elf_interpreter, X86_DEFAULT_LIB_DIR);
retval = lseek(bprm->fd, elf_ppnt->p_offset, SEEK_SET);
if(retval >= 0) {
retval = read(bprm->fd,
elf_interpreter+strlen(X86_DEFAULT_LIB_DIR),
elf_ppnt->p_filesz);
}
if(retval < 0) {
perror("load_elf_binary2");
exit(-1);
}
/* If the program interpreter is one of these two,
then assume an iBCS2 image. Otherwise assume
a native linux image. */
/* JRP - Need to add X86 lib dir stuff here... */
if (strcmp(elf_interpreter,"/usr/lib/libc.so.1") == 0 ||
strcmp(elf_interpreter,"/usr/lib/ld.so.1") == 0) {
ibcs2_interpreter = 1;
}
#if 0
printf("Using ELF interpreter %s\n", elf_interpreter);
#endif
if (retval >= 0) {
retval = open(elf_interpreter, O_RDONLY);
if(retval >= 0) {
interpreter_fd = retval;
}
else {
perror(elf_interpreter);
exit(-1);
/* retval = -errno; */
}
}
if (retval >= 0) {
retval = lseek(interpreter_fd, 0, SEEK_SET);
if(retval >= 0) {
retval = read(interpreter_fd,bprm->buf,128);
}
}
if (retval >= 0) {
interp_ex = *((struct exec *) bprm->buf); /* aout exec-header */
interp_elf_ex=*((struct elfhdr *) bprm->buf); /* elf exec-header */
}
if (retval < 0) {
perror("load_elf_binary3");
exit(-1);
free (elf_phdata);
free(elf_interpreter);
close(bprm->fd);
return retval;
}
}
elf_ppnt++;
}
/* Some simple consistency checks for the interpreter */
if (elf_interpreter){
interpreter_type = INTERPRETER_ELF | INTERPRETER_AOUT;
/* Now figure out which format our binary is */
if ((N_MAGIC(interp_ex) != OMAGIC) && (N_MAGIC(interp_ex) != ZMAGIC) &&
(N_MAGIC(interp_ex) != QMAGIC)) {
interpreter_type = INTERPRETER_ELF;
}
if (interp_elf_ex.e_ident[0] != 0x7f ||
strncmp(&interp_elf_ex.e_ident[1], "ELF",3) != 0) {
interpreter_type &= ~INTERPRETER_ELF;
}
if (!interpreter_type) {
free(elf_interpreter);
free(elf_phdata);
close(bprm->fd);
return -ELIBBAD;
}
}
/* OK, we are done with that, now set up the arg stuff,
and then start this sucker up */
if (!bprm->sh_bang) {
char * passed_p;
if (interpreter_type == INTERPRETER_AOUT) {
sprintf(passed_fileno, "%d", bprm->fd);
passed_p = passed_fileno;
if (elf_interpreter) {
bprm->p = copy_strings(1,&passed_p,bprm->page,bprm->p);
bprm->argc++;
}
}
if (!bprm->p) {
if (elf_interpreter) {
free(elf_interpreter);
}
free (elf_phdata);
close(bprm->fd);
return -E2BIG;
}
}
/* OK, This is the point of no return */
info->end_data = 0;
info->end_code = 0;
info->start_mmap = (unsigned long)ELF_START_MMAP;
info->mmap = 0;
elf_entry = (unsigned long) elf_ex.e_entry;
/* Do this so that we can load the interpreter, if need be. We will
change some of these later */
info->rss = 0;
bprm->p = setup_arg_pages(bprm->p, bprm, info);
info->start_stack = bprm->p;
/* Now we do a little grungy work by mmaping the ELF image into
* the correct location in memory. At this point, we assume that
* the image should be loaded at fixed address, not at a variable
* address.
*/
for(i = 0, elf_ppnt = elf_phdata; i < elf_ex.e_phnum; i++, elf_ppnt++) {
if (elf_ppnt->p_type == PT_LOAD) {
int elf_prot = 0;
if (elf_ppnt->p_flags & PF_R) elf_prot |= PROT_READ;
if (elf_ppnt->p_flags & PF_W) elf_prot |= PROT_WRITE;
if (elf_ppnt->p_flags & PF_X) elf_prot |= PROT_EXEC;
mapped_addr = mmap4k(X86_ELF_PAGESTART(elf_ppnt->p_vaddr),
(elf_ppnt->p_filesz +
X86_ELF_PAGEOFFSET(elf_ppnt->p_vaddr)),
elf_prot,
(MAP_FIXED | MAP_PRIVATE | MAP_DENYWRITE),
bprm->fd,
(elf_ppnt->p_offset -
X86_ELF_PAGEOFFSET(elf_ppnt->p_vaddr)));
if((unsigned long)mapped_addr == 0xffffffffffffffff) {
perror("mmap");
exit(-1);
}
#ifdef LOW_ELF_STACK
if (X86_ELF_PAGESTART(elf_ppnt->p_vaddr) < elf_stack)
elf_stack = X86_ELF_PAGESTART(elf_ppnt->p_vaddr);
#endif
if (!load_addr_set) {
load_addr = elf_ppnt->p_vaddr - elf_ppnt->p_offset;
load_addr_set = 1;
}
k = elf_ppnt->p_vaddr;
if (k < start_code) start_code = k;
k = elf_ppnt->p_vaddr + elf_ppnt->p_filesz;
if (k > elf_bss) elf_bss = k;
#if 1
if ((elf_ppnt->p_flags & PF_X) && end_code < k)
#else
if ( !(elf_ppnt->p_flags & PF_W) && end_code < k)
#endif
end_code = k;
if (end_data < k) end_data = k;
k = elf_ppnt->p_vaddr + elf_ppnt->p_memsz;
if (k > elf_brk) elf_brk = k;
}
}
if (elf_interpreter) {
if (interpreter_type & 1) {
elf_entry = load_aout_interp(&interp_ex, interpreter_fd);
}
else if (interpreter_type & 2) {
elf_entry = load_elf_interp(&interp_elf_ex, interpreter_fd,
&interp_load_addr);
}
close(interpreter_fd);
free(elf_interpreter);
if (elf_entry == ~0UL) {
printf("Unable to load interpreter\n");
free(elf_phdata);
exit(-1);
return 0;
}
}
free(elf_phdata);
if (interpreter_type != INTERPRETER_AOUT) close(bprm->fd);
info->personality = (ibcs2_interpreter ? PER_SVR4 : PER_LINUX);
#ifdef LOW_ELF_STACK
info->start_stack = bprm->p = elf_stack - 4;
#endif
bprm->p = (unsigned long)
create_elf_tables((char *)bprm->p,
bprm->argc,
bprm->envc,
(interpreter_type == INTERPRETER_ELF ? &elf_ex : NULL),
load_addr,
interp_load_addr,
(interpreter_type == INTERPRETER_AOUT ? 0 : 1),
info);
if (interpreter_type == INTERPRETER_AOUT)
info->arg_start += strlen(passed_fileno) + 1;
info->start_brk = info->brk = elf_brk;
info->end_code = end_code;
info->start_code = start_code;
info->end_data = end_data;
info->start_stack = bprm->p;
/* Calling set_brk effectively mmaps the pages that we need for the bss and break
sections */
set_brk(elf_bss, elf_brk);
padzero(elf_bss);
#if 0
printf("(start_brk) %x\n" , info->start_brk);
printf("(end_code) %x\n" , info->end_code);
printf("(start_code) %x\n" , info->start_code);
printf("(end_data) %x\n" , info->end_data);
printf("(start_stack) %x\n" , info->start_stack);
printf("(brk) %x\n" , info->brk);
#endif
if ( info->personality == PER_SVR4 )
{
/* Why this, you ask??? Well SVr4 maps page 0 as read-only,
and some applications "depend" upon this behavior.
Since we do not have the power to recompile these, we
emulate the SVr4 behavior. Sigh. */
mapped_addr = mmap4k(NULL, ALPHA_PAGE_SIZE, PROT_READ | PROT_EXEC,
MAP_FIXED | MAP_PRIVATE, -1, 0);
}
#ifdef ELF_PLAT_INIT
/*
* The ABI may specify that certain registers be set up in special
* ways (on i386 %edx is the address of a DT_FINI function, for
* example. This macro performs whatever initialization to
* the regs structure is required.
*/
ELF_PLAT_INIT(regs);
#endif
info->entry = elf_entry;
return 0;
}
int elf_exec(const char * filename, char ** argv, char ** envp,
struct target_pt_regs * regs, struct image_info *infop)
{
struct linux_binprm bprm;
int retval;
int i;
bprm.p = X86_PAGE_SIZE*MAX_ARG_PAGES-sizeof(unsigned int);
for (i=0 ; i<MAX_ARG_PAGES ; i++) /* clear page-table */
bprm.page[i] = 0;
retval = open(filename, O_RDONLY);
if (retval == -1) {
perror(filename);
exit(-1);
/* return retval; */
}
else {
bprm.fd = retval;
}
bprm.filename = (char *)filename;
bprm.sh_bang = 0;
bprm.loader = 0;
bprm.exec = 0;
bprm.dont_iput = 0;
bprm.argc = count(argv);
bprm.envc = count(envp);
retval = prepare_binprm(&bprm);
if(retval>=0) {
bprm.p = copy_strings(1, &bprm.filename, bprm.page, bprm.p);
bprm.exec = bprm.p;
bprm.p = copy_strings(bprm.envc,envp,bprm.page,bprm.p);
bprm.p = copy_strings(bprm.argc,argv,bprm.page,bprm.p);
if (!bprm.p) {
retval = -E2BIG;
}
}
if(retval>=0) {
retval = load_elf_binary(&bprm,regs,infop);
}
if(retval>=0) {
/* success. Initialize important registers */
regs->esp = infop->start_stack;
regs->eip = infop->entry;
return retval;
}
/* Something went wrong, return the inode and free the argument pages*/
for (i=0 ; i<MAX_ARG_PAGES ; i++) {
free_page((void *)bprm.page[i]);
}
return(retval);
}
static int load_aout_interp(void * exptr, int interp_fd)
{
printf("a.out interpreter not yet supported\n");
return(0);
}
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