Archipelago » qemu

/* 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 "disas.h"

#ifdef TARGET_I386

#define ELF_START_MMAP 0x80000000

typedef uint32_t  elf_greg_t;

#define ELF_NGREG (sizeof (struct target_pt_regs) / sizeof(elf_greg_t))

typedef elf_greg_t elf_gregset_t[ELF_NGREG];

typedef struct user_i387_struct elf_fpregset_t;

/*

 * This is used to ensure we don't load something for the wrong architecture.

 */

#define elf_check_arch(x) ( ((x) == EM_386) || ((x) == EM_486) )

/*

 * These are used to set parameters in the core dumps.

 */

#define ELF_CLASS        ELFCLASS32

#define ELF_DATA        ELFDATA2LSB

#define ELF_ARCH        EM_386

        /* SVR4/i386 ABI (pages 3-31, 3-32) says that when the program

           starts %edx contains a pointer to a function which might be

           registered using `atexit'.  This provides a mean for the

           dynamic linker to call DT_FINI functions for shared libraries

           that have been loaded before the code runs.

           A value of 0 tells we have no such handler.  */

#define ELF_PLAT_INIT(_r)        _r->edx = 0

#define USE_ELF_CORE_DUMP

#define ELF_EXEC_PAGESIZE        4096

#endif

#include "elf.h"

/*

 * MAX_ARG_PAGES defines the number of pages allocated for arguments

 * and envelope for the new program. 32 should suffice, this gives

 * a maximum env+arg of 128kB w/4KB pages!

 */

#define MAX_ARG_PAGES 32

/*

 * This structure is used to hold the arguments that are 

 * used when loading binaries.

 */

struct linux_binprm {

        char buf[128];

        unsigned long page[MAX_ARG_PAGES];

        unsigned long p;

        int sh_bang;

        int fd;

        int e_uid, e_gid;

        int argc, envc;

        char * filename;        /* Name of binary */

        unsigned long loader, exec;

        int dont_iput;          /* binfmt handler has put inode */

};

struct exec

{

  unsigned int a_info;   /* Use macros N_MAGIC, etc for access */

  unsigned int a_text;   /* length of text, in bytes */

  unsigned int a_data;   /* length of data, in bytes */

  unsigned int a_bss;    /* length of uninitialized data area, in bytes */

  unsigned int a_syms;   /* length of symbol table data in file, in bytes */

  unsigned int a_entry;  /* start address */

  unsigned int a_trsize; /* length of relocation info for text, in bytes */

  unsigned int a_drsize; /* length of relocation info for data, in bytes */

};

#define N_MAGIC(exec) ((exec).a_info & 0xffff)

#define OMAGIC 0407

#define NMAGIC 0410

#define ZMAGIC 0413

#define QMAGIC 0314

/* max code+data+bss space allocated to elf interpreter */

#define INTERP_MAP_SIZE (32 * 1024 * 1024)

/* max code+data+bss+brk space allocated to ET_DYN executables */

#define ET_DYN_MAP_SIZE (128 * 1024 * 1024)

/* from personality.h */

/* Flags for bug emulation. These occupy the top three bytes. */

#define STICKY_TIMEOUTS                0x4000000

#define WHOLE_SECONDS                0x2000000

/* Personality types. These go in the low byte. Avoid using the top bit,

 * it will conflict with error returns.

 */

#define PER_MASK                (0x00ff)

#define PER_LINUX                (0x0000)

#define PER_SVR4                (0x0001 | STICKY_TIMEOUTS)

#define PER_SVR3                (0x0002 | STICKY_TIMEOUTS)

#define PER_SCOSVR3                (0x0003 | STICKY_TIMEOUTS | WHOLE_SECONDS)

#define PER_WYSEV386                (0x0004 | STICKY_TIMEOUTS)

#define PER_ISCR4                (0x0005 | STICKY_TIMEOUTS)

#define PER_BSD                        (0x0006)

#define PER_XENIX                (0x0007 | STICKY_TIMEOUTS)

/* Necessary parameters */

#define NGROUPS 32

#define TARGET_ELF_EXEC_PAGESIZE TARGET_PAGE_SIZE

#define TARGET_ELF_PAGESTART(_v) ((_v) & ~(unsigned long)(TARGET_ELF_EXEC_PAGESIZE-1))

#define TARGET_ELF_PAGEOFFSET(_v) ((_v) & (TARGET_ELF_EXEC_PAGESIZE-1))

#define INTERPRETER_NONE 0

#define INTERPRETER_AOUT 1

#define INTERPRETER_ELF 2

#define DLINFO_ITEMS 12

#define put_user(x,ptr) (void)(*(ptr) = (typeof(*ptr))(x))

#define get_user(ptr) (typeof(*ptr))(*(ptr))

static inline void memcpy_fromfs(void * to, const void * from, unsigned long n)

{

        memcpy(to, from, n);

}

static inline void memcpy_tofs(void * to, const void * from, unsigned long n)

{

        memcpy(to, from, n);

}

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 */

}

static void bswap_shdr(Elf32_Shdr *shdr)

{

    bswap32s(&shdr->sh_name);

    bswap32s(&shdr->sh_type);

    bswap32s(&shdr->sh_flags);

    bswap32s(&shdr->sh_addr);

    bswap32s(&shdr->sh_offset);

    bswap32s(&shdr->sh_size);

    bswap32s(&shdr->sh_link);

    bswap32s(&shdr->sh_info);

    bswap32s(&shdr->sh_addralign);

    bswap32s(&shdr->sh_entsize);

}

static void bswap_sym(Elf32_Sym *sym)

{

    bswap32s(&sym->st_name);

    bswap32s(&sym->st_value);

    bswap32s(&sym->st_size);

    bswap16s(&sym->st_shndx);

}

#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 = (void *)target_mmap(0, host_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)

{

    target_munmap((unsigned long)pageaddr, host_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 % TARGET_PAGE_SIZE;

                if (!(pag = (char *) page[p/TARGET_PAGE_SIZE]) &&

                    !(pag = (char *) page[p/TARGET_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, size, error;

    int i;

    /* Create enough stack to hold everything.  If we don't use

     * it for args, we'll use it for something else...

     */

    size = x86_stack_size;

    if (size < MAX_ARG_PAGES*TARGET_PAGE_SIZE)

        size = MAX_ARG_PAGES*TARGET_PAGE_SIZE;

    error = target_mmap(0, 

                        size + host_page_size,

                        PROT_READ | PROT_WRITE,

                        MAP_PRIVATE | MAP_ANONYMOUS,

                        -1, 0);

    if (error == -1) {

        perror("stk mmap");

        exit(-1);

    }

    /* we reserve one extra page at the top of the stack as guard */

    target_mprotect(error + size, host_page_size, PROT_NONE);

    stack_base = error + size - MAX_ARG_PAGES*TARGET_PAGE_SIZE;

    p += stack_base;

    if (bprm->loader) {

        bprm->loader += stack_base;

    }

    bprm->exec += stack_base;

    for (i = 0 ; i < MAX_ARG_PAGES ; i++) {

        if (bprm->page[i]) {

            info->rss++;

            memcpy((void *)stack_base, (void *)bprm->page[i], TARGET_PAGE_SIZE);

            free_page((void *)bprm->page[i]);

        }

        stack_base += TARGET_PAGE_SIZE;

    }

    return p;

}

static void set_brk(unsigned long start, unsigned long end)

{

        /* page-align the start and end addresses... */

        start = HOST_PAGE_ALIGN(start);

        end = HOST_PAGE_ALIGN(end);

        if (end <= start)

                return;

        if(target_mmap(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 & (host_page_size-1);        /* was TARGET_PAGE_SIZE - JRP */

        if (nbyte) {

            nbyte = host_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 load_bias,

                                        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 */

          NEW_AUX_ENT (AT_PHDR, (target_ulong)(load_addr + exec->e_phoff));

          NEW_AUX_ENT (AT_PHENT, (target_ulong)(sizeof (struct elf_phdr)));

          NEW_AUX_ENT (AT_PHNUM, (target_ulong)(exec->e_phnum));

          NEW_AUX_ENT (AT_PAGESZ, (target_ulong)(TARGET_PAGE_SIZE));

          NEW_AUX_ENT (AT_BASE, (target_ulong)(interp_load_addr));

          NEW_AUX_ENT (AT_FLAGS, (target_ulong)0);

          NEW_AUX_ENT (AT_ENTRY, load_bias + exec->e_entry);

          NEW_AUX_ENT (AT_UID, (target_ulong) getuid());

          NEW_AUX_ENT (AT_EUID, (target_ulong) geteuid());

          NEW_AUX_ENT (AT_GID, (target_ulong) getgid());

          NEW_AUX_ENT (AT_EGID, (target_ulong) 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 = 0;

        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;

#ifdef BSWAP_NEEDED

        bswap_ehdr(interp_elf_ex);

#endif

        /* 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 > TARGET_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

        if (interp_elf_ex->e_type == ET_DYN) {

            /* in order to avoid harcoding the interpreter load

               address in qemu, we allocate a big enough memory zone */

            error = target_mmap(0, INTERP_MAP_SIZE,

                                PROT_NONE, MAP_PRIVATE | MAP_ANON, 

                                -1, 0);

            if (error == -1) {

                perror("mmap");

                exit(-1);

            }

            load_addr = error;

            load_addr_set = 1;

        }

        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 = target_mmap(load_addr+TARGET_ELF_PAGESTART(vaddr),

                 eppnt->p_filesz + TARGET_ELF_PAGEOFFSET(eppnt->p_vaddr),

                 elf_prot,

                 elf_type,

                 interpreter_fd,

                 eppnt->p_offset - TARGET_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 = TARGET_ELF_PAGESTART(elf_bss + host_page_size - 1); /* What we have mapped so far */

        /* Map the last of the bss segment */

        if (last_bss > elf_bss) {

            target_mmap(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;

}

/* Best attempt to load symbols from this ELF object. */

static void load_symbols(struct elfhdr *hdr, int fd)

{

    unsigned int i;

    struct elf_shdr sechdr, symtab, strtab;

    char *strings;

    lseek(fd, hdr->e_shoff, SEEK_SET);

    for (i = 0; i < hdr->e_shnum; i++) {

        if (read(fd, &sechdr, sizeof(sechdr)) != sizeof(sechdr))

            return;

#ifdef BSWAP_NEEDED

        bswap_shdr(&sechdr);

#endif

        if (sechdr.sh_type == SHT_SYMTAB) {

            symtab = sechdr;

            lseek(fd, hdr->e_shoff

                  + sizeof(sechdr) * sechdr.sh_link, SEEK_SET);

            if (read(fd, &strtab, sizeof(strtab))

                != sizeof(strtab))

                return;

#ifdef BSWAP_NEEDED

            bswap_shdr(&strtab);

#endif

            goto found;

        }

    }

    return; /* Shouldn't happen... */

 found:

    /* Now know where the strtab and symtab are.  Snarf them. */

    disas_symtab = malloc(symtab.sh_size);

    disas_strtab = strings = malloc(strtab.sh_size);

    if (!disas_symtab || !disas_strtab)

        return;

    lseek(fd, symtab.sh_offset, SEEK_SET);

    if (read(fd, disas_symtab, symtab.sh_size) != symtab.sh_size)

        return;

#ifdef BSWAP_NEEDED

    for (i = 0; i < symtab.sh_size / sizeof(struct elf_sym); i++)

        bswap_sym(disas_symtab + sizeof(struct elf_sym)*i);

#endif

    lseek(fd, strtab.sh_offset, SEEK_SET);

    if (read(fd, strings, strtab.sh_size) != strtab.sh_size)

        return;

    disas_num_syms = symtab.sh_size / sizeof(struct elf_sym);

}

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, load_bias;

    int load_addr_set = 0;

    unsigned int interpreter_type = INTERPRETER_NONE;

    unsigned char ibcs2_interpreter;

    int i;

    unsigned long 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;

    load_bias = 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);

            if (elf_interpreter == NULL) {

                free (elf_phdata);

                close(bprm->fd);

                return -ENOMEM;

            }

            retval = lseek(bprm->fd, elf_ppnt->p_offset, SEEK_SET);

            if(retval >= 0) {

                retval = read(bprm->fd, elf_interpreter, 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(path(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;