[qemu.git] / linux-user / elfload.c

/* 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 "gemu.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...
     */
    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);
}