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/*
 * Preloader for ld.so
 *
 * Copyright (C) 1995,96,97,98,99,2000,2001,2002 Free Software Foundation, Inc.
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 * Copyright (C) 2004 Mike McCormack for CodeWeavers
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 * Copyright (C) 2004 Alexandre Julliard
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.
 *
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the Free Software
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 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA
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 */

/*
 * Design notes
 *
 * The goal of this program is to be a workaround for exec-shield, as used
 *  by the Linux kernel distributed with Fedora Core and other distros.
 *
 * To do this, we implement our own shared object loader that reserves memory
 * that is important to Wine, and then loads the main binary and its ELF
 * interpreter.
 *
 * We will try to set up the stack and memory area so that the program that
 * loads after us (eg. the wine binary) never knows we were here, except that
 * areas of memory it needs are already magically reserved.
 *
 * The following memory areas are important to Wine:
 *  0x00000000 - 0x00110000  the DOS area
 *  0x80000000 - 0x81000000  the shared heap
 *  ???        - ???         the PE binary load address (usually starting at 0x00400000)
 *
 * If this program is used as the shared object loader, the only difference
 * that the loaded programs should see is that this loader will be mapped
 * into memory when it starts.
 */

/*
 * References (things I consulted to understand how ELF loading works):
 *
 * glibc 2.3.2   elf/dl-load.c
 *  http://www.gnu.org/directory/glibc.html
 *
 * Linux 2.6.4   fs/binfmt_elf.c
 *  ftp://ftp.kernel.org/pub/linux/kernel/v2.6/linux-2.6.4.tar.bz2
 *
 * Userland exec, by <grugq@hcunix.net>
 *  http://cert.uni-stuttgart.de/archive/bugtraq/2004/01/msg00002.html
 *
 * The ELF specification:
 *  http://www.linuxbase.org/spec/booksets/LSB-Embedded/LSB-Embedded/book387.html
 */

#include "config.h"
#include "wine/port.h"

#include <stdarg.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/types.h>
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#ifdef HAVE_SYS_STAT_H
# include <sys/stat.h>
#endif
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#include <fcntl.h>
#ifdef HAVE_SYS_MMAN_H
# include <sys/mman.h>
#endif
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#ifdef HAVE_SYS_SYSCALL_H
# include <sys/syscall.h>
#endif
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#ifdef HAVE_UNISTD_H
# include <unistd.h>
#endif
#ifdef HAVE_ELF_H
# include <elf.h>
#endif
#ifdef HAVE_LINK_H
# include <link.h>
#endif
#ifdef HAVE_SYS_LINK_H
# include <sys/link.h>
#endif

#include "main.h"

/* ELF definitions */
#define ELF_PREFERRED_ADDRESS(loader, maplength, mapstartpref) (mapstartpref)
#define ELF_FIXED_ADDRESS(loader, mapstart) ((void) 0)

#define MAP_BASE_ADDR(l)     0

#ifndef MAP_COPY
#define MAP_COPY MAP_PRIVATE
#endif
#ifndef MAP_NORESERVE
#define MAP_NORESERVE 0
#endif

static struct wine_preload_info preload_info[] =
{
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    { (void *)0x00000000, 0x60000000 },  /* low memory area */
    { (void *)0x7f000000, 0x02000000 },  /* top-down allocations + shared heap */
    { 0, 0 },                            /* PE exe range set with WINEPRELOADRESERVE */
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    { 0, 0 }                             /* end of list */
};

/* debugging */
#undef DUMP_SEGMENTS
#undef DUMP_AUX_INFO
#undef DUMP_SYMS

/* older systems may not define these */
#ifndef PT_TLS
#define PT_TLS 7
#endif

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#ifndef AT_SYSINFO
#define AT_SYSINFO 32
#endif
#ifndef AT_SYSINFO_EHDR
#define AT_SYSINFO_EHDR 33
#endif

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#ifndef DT_GNU_HASH
#define DT_GNU_HASH 0x6ffffef5
#endif

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static unsigned int page_size, page_mask;
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static char *preloader_start, *preloader_end;
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struct wld_link_map {
    ElfW(Addr) l_addr;
    ElfW(Dyn) *l_ld;
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    ElfW(Phdr)*l_phdr;
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    ElfW(Addr) l_entry;
    ElfW(Half) l_ldnum;
    ElfW(Half) l_phnum;
    ElfW(Addr) l_map_start, l_map_end;
    ElfW(Addr) l_interp;
};


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/*
 * The __bb_init_func is an empty function only called when file is
 * compiled with gcc flags "-fprofile-arcs -ftest-coverage".  This
 * function is normally provided by libc's startup files, but since we
 * build the preloader with "-nostartfiles -nodefaultlibs", we have to
 * provide our own (empty) version, otherwise linker fails.
 */
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void __bb_init_func(void) { return; }
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/* similar to the above but for -fstack-protector */
void *__stack_chk_guard = 0;
void __stack_chk_fail(void) { return; }
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/* data for setting up the glibc-style thread-local storage in %gs */

static int thread_data[256];

struct
{
    /* this is the kernel modify_ldt struct */
    unsigned int  entry_number;
    unsigned long base_addr;
    unsigned int  limit;
    unsigned int  seg_32bit : 1;
    unsigned int  contents : 2;
    unsigned int  read_exec_only : 1;
    unsigned int  limit_in_pages : 1;
    unsigned int  seg_not_present : 1;
    unsigned int  useable : 1;
    unsigned int  garbage : 25;
} thread_ldt = { -1, (unsigned long)thread_data, 0xfffff, 1, 0, 0, 1, 0, 1, 0 };


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/*
 * The _start function is the entry and exit point of this program
 *
 *  It calls wld_start, passing a pointer to the args it receives
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 *  then jumps to the address wld_start returns.
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 */
void _start();
extern char _end[];
__ASM_GLOBAL_FUNC(_start,
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                  "\tmovl $243,%eax\n"        /* SYS_set_thread_area */
                  "\tmovl $thread_ldt,%ebx\n"
                  "\tint $0x80\n"             /* allocate gs segment */
                  "\torl %eax,%eax\n"
                  "\tjl 1f\n"
                  "\tmovl thread_ldt,%eax\n"  /* thread_ldt.entry_number */
                  "\tshl $3,%eax\n"
                  "\torl $3,%eax\n"
                  "\tmov %ax,%gs\n"
                  "\tmov %ax,%fs\n"           /* set %fs too so libwine can retrieve it later on */
                  "1:\tmovl %esp,%eax\n"
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                  "\tleal -136(%esp),%esp\n"  /* allocate some space for extra aux values */
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                  "\tpushl %eax\n"            /* orig stack pointer */
                  "\tpushl %esp\n"            /* ptr to orig stack pointer */
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                  "\tcall wld_start\n"
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                  "\tpopl %ecx\n"             /* remove ptr to stack pointer */
                  "\tpopl %esp\n"             /* new stack pointer */
                  "\tpush %eax\n"             /* ELF interpreter entry point */
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                  "\txor %eax,%eax\n"
                  "\txor %ecx,%ecx\n"
                  "\txor %edx,%edx\n"
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                  "\tmov %ax,%gs\n"           /* clear %gs again */
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                  "\tret\n")

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/* wrappers for Linux system calls */

#define SYSCALL_RET(ret) (((ret) < 0 && (ret) > -4096) ? -1 : (ret))

static inline __attribute__((noreturn)) void wld_exit( int code )
{
    for (;;)  /* avoid warning */
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        __asm__ __volatile__( "pushl %%ebx; movl %1,%%ebx; int $0x80; popl %%ebx"
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                              : : "a" (SYS_exit), "r" (code) );
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}

static inline int wld_open( const char *name, int flags )
{
    int ret;
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    __asm__ __volatile__( "pushl %%ebx; movl %2,%%ebx; int $0x80; popl %%ebx"
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                          : "=a" (ret) : "0" (SYS_open), "r" (name), "c" (flags) );
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    return SYSCALL_RET(ret);
}

static inline int wld_close( int fd )
{
    int ret;
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    __asm__ __volatile__( "pushl %%ebx; movl %2,%%ebx; int $0x80; popl %%ebx"
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                          : "=a" (ret) : "0" (SYS_close), "r" (fd) );
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    return SYSCALL_RET(ret);
}

static inline ssize_t wld_read( int fd, void *buffer, size_t len )
{
    int ret;
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    __asm__ __volatile__( "pushl %%ebx; movl %2,%%ebx; int $0x80; popl %%ebx"
                          : "=a" (ret)
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                          : "0" (SYS_read), "r" (fd), "c" (buffer), "d" (len)
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                          : "memory" );
    return SYSCALL_RET(ret);
}

static inline ssize_t wld_write( int fd, const void *buffer, size_t len )
{
    int ret;
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    __asm__ __volatile__( "pushl %%ebx; movl %2,%%ebx; int $0x80; popl %%ebx"
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                          : "=a" (ret) : "0" (SYS_write), "r" (fd), "c" (buffer), "d" (len) );
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    return SYSCALL_RET(ret);
}

static inline int wld_mprotect( const void *addr, size_t len, int prot )
{
    int ret;
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    __asm__ __volatile__( "pushl %%ebx; movl %2,%%ebx; int $0x80; popl %%ebx"
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                          : "=a" (ret) : "0" (SYS_mprotect), "r" (addr), "c" (len), "d" (prot) );
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    return SYSCALL_RET(ret);
}

static void *wld_mmap( void *start, size_t len, int prot, int flags, int fd, off_t offset )
{
    int ret;

    struct
    {
        void        *addr;
        unsigned int length;
        unsigned int prot;
        unsigned int flags;
        unsigned int fd;
        unsigned int offset;
    } args;

    args.addr   = start;
    args.length = len;
    args.prot   = prot;
    args.flags  = flags;
    args.fd     = fd;
    args.offset = offset;
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    __asm__ __volatile__( "pushl %%ebx; movl %2,%%ebx; int $0x80; popl %%ebx"
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                          : "=a" (ret) : "0" (SYS_mmap), "q" (&args) : "memory" );
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    return (void *)SYSCALL_RET(ret);
}

static inline uid_t wld_getuid(void)
{
    uid_t ret;
    __asm__( "int $0x80" : "=a" (ret) : "0" (SYS_getuid) );
    return ret;
}

static inline uid_t wld_geteuid(void)
{
    uid_t ret;
    __asm__( "int $0x80" : "=a" (ret) : "0" (SYS_geteuid) );
    return ret;
}

static inline gid_t wld_getgid(void)
{
    gid_t ret;
    __asm__( "int $0x80" : "=a" (ret) : "0" (SYS_getgid) );
    return ret;
}

static inline gid_t wld_getegid(void)
{
    gid_t ret;
    __asm__( "int $0x80" : "=a" (ret) : "0" (SYS_getegid) );
    return ret;
}

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static inline int wld_prctl( int code, int arg )
{
    int ret;
    __asm__ __volatile__( "pushl %%ebx; movl %2,%%ebx; int $0x80; popl %%ebx"
                          : "=a" (ret) : "0" (SYS_prctl), "r" (code), "c" (arg) );
    return SYSCALL_RET(ret);
}

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/* replacement for libc functions */

static int wld_strcmp( const char *str1, const char *str2 )
{
    while (*str1 && (*str1 == *str2)) { str1++; str2++; }
    return *str1 - *str2;
}

static int wld_strncmp( const char *str1, const char *str2, size_t len )
{
    if (len <= 0) return 0;
    while ((--len > 0) && *str1 && (*str1 == *str2)) { str1++; str2++; }
    return *str1 - *str2;
}

static inline void *wld_memset( void *dest, int val, size_t len )
{
    char *dst = dest;
    while (len--) *dst++ = val;
    return dest;
}

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/*
 * wld_printf - just the basics
 *
 *  %x prints a hex number
 *  %s prints a string
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 *  %p prints a pointer
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 */
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static int wld_vsprintf(char *buffer, const char *fmt, va_list args )
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{
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    static const char hex_chars[16] = "0123456789abcdef";
    const char *p = fmt;
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    char *str = buffer;
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    int i;
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    while( *p )
    {
        if( *p == '%' )
        {
            p++;
            if( *p == 'x' )
            {
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                unsigned int x = va_arg( args, unsigned int );
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                for(i=7; i>=0; i--)
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                    *str++ = hex_chars[(x>>(i*4))&0xf];
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            }
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            else if (p[0] == 'l' && p[1] == 'x')
            {
                unsigned long x = va_arg( args, unsigned long );
                for(i=7; i>=0; i--)
                    *str++ = hex_chars[(x>>(i*4))&0xf];
                p++;
            }
            else if( *p == 'p' )
            {
                unsigned long x = (unsigned long)va_arg( args, void * );
                for(i=7; i>=0; i--)
                    *str++ = hex_chars[(x>>(i*4))&0xf];
            }
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            else if( *p == 's' )
            {
                char *s = va_arg( args, char * );
                while(*s)
                    *str++ = *s++;
            }
            else if( *p == 0 )
                break;
            p++;
        }
        *str++ = *p++;
    }
    *str = 0;
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    return str - buffer;
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}

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static __attribute__((format(printf,1,2))) void wld_printf(const char *fmt, ... )
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{
    va_list args;
    char buffer[256];
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    int len;
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    va_start( args, fmt );
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    len = wld_vsprintf(buffer, fmt, args );
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    va_end( args );
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    wld_write(2, buffer, len);
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}

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static __attribute__((noreturn,format(printf,1,2))) void fatal_error(const char *fmt, ... )
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{
    va_list args;
    char buffer[256];
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    int len;
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    va_start( args, fmt );
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    len = wld_vsprintf(buffer, fmt, args );
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    va_end( args );
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    wld_write(2, buffer, len);
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    wld_exit(1);
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}

#ifdef DUMP_AUX_INFO
/*
 *  Dump interesting bits of the ELF auxv_t structure that is passed
 *   as the 4th parameter to the _start function
 */
static void dump_auxiliary( ElfW(auxv_t) *av )
{
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#define NAME(at) { at, #at }
    static const struct { int val; const char *name; } names[] =
    {
        NAME(AT_BASE),
        NAME(AT_CLKTCK),
        NAME(AT_EGID),
        NAME(AT_ENTRY),
        NAME(AT_EUID),
        NAME(AT_FLAGS),
        NAME(AT_GID),
        NAME(AT_HWCAP),
        NAME(AT_PAGESZ),
        NAME(AT_PHDR),
        NAME(AT_PHENT),
        NAME(AT_PHNUM),
        NAME(AT_PLATFORM),
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        NAME(AT_SYSINFO),
        NAME(AT_SYSINFO_EHDR),
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        NAME(AT_UID),
        { 0, NULL }
    };
#undef NAME

    int i;

    for (  ; av->a_type != AT_NULL; av++)
    {
        for (i = 0; names[i].name; i++) if (names[i].val == av->a_type) break;
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        if (names[i].name) wld_printf("%s = %lx\n", names[i].name, av->a_un.a_val);
        else wld_printf( "%x = %lx\n", av->a_type, av->a_un.a_val );
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    }
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}
#endif

/*
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 * set_auxiliary_values
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 *
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 * Set the new auxiliary values
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 */
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static void set_auxiliary_values( ElfW(auxv_t) *av, const ElfW(auxv_t) *new_av,
                                  const ElfW(auxv_t) *delete_av, void **stack )
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{
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    int i, j, av_count = 0, new_count = 0, delete_count = 0;
    char *src, *dst;
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    /* count how many aux values we have already */
    while (av[av_count].a_type != AT_NULL) av_count++;

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    /* delete unwanted values */
    for (j = 0; delete_av[j].a_type != AT_NULL; j++)
    {
        for (i = 0; i < av_count; i++) if (av[i].a_type == delete_av[j].a_type)
        {
            av[i].a_type = av[av_count-1].a_type;
            av[i].a_un.a_val = av[av_count-1].a_un.a_val;
            av[--av_count].a_type = AT_NULL;
            delete_count++;
            break;
        }
    }

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    /* count how many values we have in new_av that aren't in av */
    for (j = 0; new_av[j].a_type != AT_NULL; j++)
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    {
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        for (i = 0; i < av_count; i++) if (av[i].a_type == new_av[j].a_type) break;
        if (i == av_count) new_count++;
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    }
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    src = (char *)*stack;
    dst = src - (new_count - delete_count) * sizeof(*av);
    if (new_count > delete_count)   /* need to make room for the extra values */
    {
        int len = (char *)(av + av_count + 1) - src;
        for (i = 0; i < len; i++) dst[i] = src[i];
    }
    else if (new_count < delete_count)  /* get rid of unused values */
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    {
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        int len = (char *)(av + av_count + 1) - dst;
        for (i = len - 1; i >= 0; i--) dst[i] = src[i];
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    }
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    *stack = dst;
    av -= (new_count - delete_count);
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    /* now set the values */
    for (j = 0; new_av[j].a_type != AT_NULL; j++)
    {
        for (i = 0; i < av_count; i++) if (av[i].a_type == new_av[j].a_type) break;
        if (i < av_count) av[i].a_un.a_val = new_av[j].a_un.a_val;
        else
        {
            av[av_count].a_type     = new_av[j].a_type;
            av[av_count].a_un.a_val = new_av[j].a_un.a_val;
            av_count++;
        }
    }

#ifdef DUMP_AUX_INFO
    wld_printf("New auxiliary info:\n");
    dump_auxiliary( av );
#endif
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}

/*
 * get_auxiliary
 *
 * Get a field of the auxiliary structure
 */
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static int get_auxiliary( ElfW(auxv_t) *av, int type, int def_val )
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{
  for ( ; av->a_type != AT_NULL; av++)
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      if( av->a_type == type ) return av->a_un.a_val;
  return def_val;
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}

/*
 * map_so_lib
 *
 * modelled after _dl_map_object_from_fd() from glibc-2.3.1/elf/dl-load.c
 *
 * This function maps the segments from an ELF object, and optionally
 *  stores information about the mapping into the auxv_t structure.
 */
static void map_so_lib( const char *name, struct wld_link_map *l)
{
    int fd;
    unsigned char buf[0x800];
    ElfW(Ehdr) *header = (ElfW(Ehdr)*)buf;
    ElfW(Phdr) *phdr, *ph;
    /* Scan the program header table, collecting its load commands.  */
    struct loadcmd
      {
        ElfW(Addr) mapstart, mapend, dataend, allocend;
        off_t mapoff;
        int prot;
      } loadcmds[16], *c;
    size_t nloadcmds = 0, maplength;

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    fd = wld_open( name, O_RDONLY );
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    if (fd == -1) fatal_error("%s: could not open\n", name );

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    if (wld_read( fd, buf, sizeof(buf) ) != sizeof(buf))
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        fatal_error("%s: failed to read ELF header\n", name);

    phdr = (void*) (((unsigned char*)buf) + header->e_phoff);

    if( ( header->e_ident[0] != 0x7f ) ||
        ( header->e_ident[1] != 'E' ) ||
        ( header->e_ident[2] != 'L' ) ||
        ( header->e_ident[3] != 'F' ) )
        fatal_error( "%s: not an ELF binary... don't know how to load it\n", name );

    if( header->e_machine != EM_386 )
        fatal_error("%s: not an i386 ELF binary... don't know how to load it\n", name );

    if (header->e_phnum > sizeof(loadcmds)/sizeof(loadcmds[0]))
        fatal_error( "%s: oops... not enough space for load commands\n", name );

    maplength = header->e_phnum * sizeof (ElfW(Phdr));
    if (header->e_phoff + maplength > sizeof(buf))
        fatal_error( "%s: oops... not enough space for ELF headers\n", name );

    l->l_ld = 0;
    l->l_addr = 0;
    l->l_phdr = 0;
    l->l_phnum = header->e_phnum;
    l->l_entry = header->e_entry;
    l->l_interp = 0;

    for (ph = phdr; ph < &phdr[l->l_phnum]; ++ph)
    {

#ifdef DUMP_SEGMENTS
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      wld_printf( "ph = %p\n", ph );
615 616 617 618 619 620 621 622 623 624 625 626 627 628 629 630 631 632 633 634 635 636 637 638 639 640 641 642 643 644 645 646 647 648 649 650 651 652 653 654 655 656 657 658 659 660 661 662 663 664 665 666 667 668 669 670 671 672 673 674 675 676 677 678 679 680 681 682 683 684 685 686 687 688 689 690 691 692 693
      wld_printf( " p_type   = %x\n", ph->p_type );
      wld_printf( " p_flags  = %x\n", ph->p_flags );
      wld_printf( " p_offset = %x\n", ph->p_offset );
      wld_printf( " p_vaddr  = %x\n", ph->p_vaddr );
      wld_printf( " p_paddr  = %x\n", ph->p_paddr );
      wld_printf( " p_filesz = %x\n", ph->p_filesz );
      wld_printf( " p_memsz  = %x\n", ph->p_memsz );
      wld_printf( " p_align  = %x\n", ph->p_align );
#endif

      switch (ph->p_type)
        {
          /* These entries tell us where to find things once the file's
             segments are mapped in.  We record the addresses it says
             verbatim, and later correct for the run-time load address.  */
        case PT_DYNAMIC:
          l->l_ld = (void *) ph->p_vaddr;
          l->l_ldnum = ph->p_memsz / sizeof (Elf32_Dyn);
          break;

        case PT_PHDR:
          l->l_phdr = (void *) ph->p_vaddr;
          break;

        case PT_LOAD:
          {
            if ((ph->p_align & page_mask) != 0)
              fatal_error( "%s: ELF load command alignment not page-aligned\n", name );

            if (((ph->p_vaddr - ph->p_offset) & (ph->p_align - 1)) != 0)
              fatal_error( "%s: ELF load command address/offset not properly aligned\n", name );

            c = &loadcmds[nloadcmds++];
            c->mapstart = ph->p_vaddr & ~(ph->p_align - 1);
            c->mapend = ((ph->p_vaddr + ph->p_filesz + page_mask) & ~page_mask);
            c->dataend = ph->p_vaddr + ph->p_filesz;
            c->allocend = ph->p_vaddr + ph->p_memsz;
            c->mapoff = ph->p_offset & ~(ph->p_align - 1);

            c->prot = 0;
            if (ph->p_flags & PF_R)
              c->prot |= PROT_READ;
            if (ph->p_flags & PF_W)
              c->prot |= PROT_WRITE;
            if (ph->p_flags & PF_X)
              c->prot |= PROT_EXEC;
          }
          break;

        case PT_INTERP:
          l->l_interp = ph->p_vaddr;
          break;

        case PT_TLS:
          /*
           * We don't need to set anything up because we're
           * emulating the kernel, not ld-linux.so.2
           * The ELF loader will set up the TLS data itself.
           */
        case PT_SHLIB:
        case PT_NOTE:
        default:
          break;
        }
    }

    /* Now process the load commands and map segments into memory.  */
    c = loadcmds;

    /* Length of the sections to be loaded.  */
    maplength = loadcmds[nloadcmds - 1].allocend - c->mapstart;

    if( header->e_type == ET_DYN )
    {
        ElfW(Addr) mappref;
        mappref = (ELF_PREFERRED_ADDRESS (loader, maplength, c->mapstart)
                   - MAP_BASE_ADDR (l));

        /* Remember which part of the address space this object uses.  */
694
        l->l_map_start = (ElfW(Addr)) wld_mmap ((void *) mappref, maplength,
695 696 697 698 699 700 701 702
                                              c->prot, MAP_COPY | MAP_FILE,
                                              fd, c->mapoff);
        /* wld_printf("set  : offset = %x\n", c->mapoff); */
        /* wld_printf("l->l_map_start = %x\n", l->l_map_start); */

        l->l_map_end = l->l_map_start + maplength;
        l->l_addr = l->l_map_start - c->mapstart;

703
        wld_mprotect ((caddr_t) (l->l_addr + c->mapend),
704 705 706 707 708 709 710 711 712
                    loadcmds[nloadcmds - 1].allocend - c->mapend,
                    PROT_NONE);
        goto postmap;
    }
    else
    {
        /* sanity check */
        if ((char *)c->mapstart + maplength > preloader_start &&
            (char *)c->mapstart <= preloader_end)
713 714
            fatal_error( "%s: binary overlaps preloader (%p-%p)\n",
                         name, (char *)c->mapstart, (char *)c->mapstart + maplength );
715 716 717 718 719 720 721 722 723 724 725 726

        ELF_FIXED_ADDRESS (loader, c->mapstart);
    }

    /* Remember which part of the address space this object uses.  */
    l->l_map_start = c->mapstart + l->l_addr;
    l->l_map_end = l->l_map_start + maplength;

    while (c < &loadcmds[nloadcmds])
      {
        if (c->mapend > c->mapstart)
            /* Map the segment contents from the file.  */
727
            wld_mmap ((void *) (l->l_addr + c->mapstart),
728 729 730 731 732 733 734 735 736 737 738 739 740 741 742 743 744 745 746 747 748 749 750 751 752 753 754 755 756 757 758 759 760 761 762 763 764 765 766 767
                        c->mapend - c->mapstart, c->prot,
                        MAP_FIXED | MAP_COPY | MAP_FILE, fd, c->mapoff);

      postmap:
        if (l->l_phdr == 0
            && (ElfW(Off)) c->mapoff <= header->e_phoff
            && ((size_t) (c->mapend - c->mapstart + c->mapoff)
                >= header->e_phoff + header->e_phnum * sizeof (ElfW(Phdr))))
          /* Found the program header in this segment.  */
          l->l_phdr = (void *)(unsigned int) (c->mapstart + header->e_phoff - c->mapoff);

        if (c->allocend > c->dataend)
          {
            /* Extra zero pages should appear at the end of this segment,
               after the data mapped from the file.   */
            ElfW(Addr) zero, zeroend, zeropage;

            zero = l->l_addr + c->dataend;
            zeroend = l->l_addr + c->allocend;
            zeropage = (zero + page_mask) & ~page_mask;

            /*
             * This is different from the dl-load load...
             *  ld-linux.so.2 relies on the whole page being zero'ed
             */
            zeroend = (zeroend + page_mask) & ~page_mask;

            if (zeroend < zeropage)
            {
              /* All the extra data is in the last page of the segment.
                 We can just zero it.  */
              zeropage = zeroend;
            }

            if (zeropage > zero)
              {
                /* Zero the final part of the last page of the segment.  */
                if ((c->prot & PROT_WRITE) == 0)
                  {
                    /* Dag nab it.  */
768
                    wld_mprotect ((caddr_t) (zero & ~page_mask), page_size, c->prot|PROT_WRITE);
769
                  }
770
                wld_memset ((void *) zero, '\0', zeropage - zero);
771
                if ((c->prot & PROT_WRITE) == 0)
772
                  wld_mprotect ((caddr_t) (zero & ~page_mask), page_size, c->prot);
773 774 775 776 777 778
              }

            if (zeroend > zeropage)
              {
                /* Map the remaining zero pages in from the zero fill FD.  */
                caddr_t mapat;
779
                mapat = wld_mmap ((caddr_t) zeropage, zeroend - zeropage,
780 781 782 783 784 785 786 787 788 789 790 791 792
                                c->prot, MAP_ANON|MAP_PRIVATE|MAP_FIXED,
                                -1, 0);
              }
          }

        ++c;
      }

    if (l->l_phdr == NULL) fatal_error("no program header\n");

    l->l_phdr = (void *)((ElfW(Addr))l->l_phdr + l->l_addr);
    l->l_entry += l->l_addr;

793
    wld_close( fd );
794 795 796
}


797 798 799 800 801 802 803 804 805 806 807 808 809
static unsigned int elf_hash( const char *name )
{
    unsigned int hi, hash = 0;
    while (*name)
    {
        hash = (hash << 4) + (unsigned char)*name++;
        hi = hash & 0xf0000000;
        hash ^= hi;
        hash ^= hi >> 24;
    }
    return hash;
}

810 811 812 813 814 815 816
static unsigned int gnu_hash( const char *name )
{
    unsigned int h = 5381;
    while (*name) h = h * 33 + (unsigned char)*name++;
    return h;
}

817 818 819
/*
 * Find a symbol in the symbol table of the executable loaded
 */
820
static void *find_symbol( const ElfW(Phdr) *phdr, int num, const char *var, int type )
821 822 823 824
{
    const ElfW(Dyn) *dyn = NULL;
    const ElfW(Phdr) *ph;
    const ElfW(Sym) *symtab = NULL;
825
    const Elf_Symndx *hashtab = NULL;
826
    const Elf32_Word *gnu_hashtab = NULL;
827
    const char *strings = NULL;
828
    Elf_Symndx idx;
829 830 831

    /* check the values */
#ifdef DUMP_SYMS
832
    wld_printf("%p %x\n", phdr, num );
833 834 835 836 837 838 839 840 841 842 843 844 845 846 847 848 849 850 851 852 853 854 855 856 857 858
#endif
    if( ( phdr == NULL ) || ( num == 0 ) )
    {
        wld_printf("could not find PT_DYNAMIC header entry\n");
        return NULL;
    }

    /* parse the (already loaded) ELF executable's header */
    for (ph = phdr; ph < &phdr[num]; ++ph)
    {
        if( PT_DYNAMIC == ph->p_type )
        {
            dyn = (void *) ph->p_vaddr;
            num = ph->p_memsz / sizeof (Elf32_Dyn);
            break;
        }
    }
    if( !dyn ) return NULL;

    while( dyn->d_tag )
    {
        if( dyn->d_tag == DT_STRTAB )
            strings = (const char*) dyn->d_un.d_ptr;
        if( dyn->d_tag == DT_SYMTAB )
            symtab = (const ElfW(Sym) *)dyn->d_un.d_ptr;
        if( dyn->d_tag == DT_HASH )
859
            hashtab = (const Elf_Symndx *)dyn->d_un.d_ptr;
860 861
        if( dyn->d_tag == DT_GNU_HASH )
            gnu_hashtab = (const Elf32_Word *)dyn->d_un.d_ptr;
862 863 864 865 866 867 868 869
#ifdef DUMP_SYMS
        wld_printf("%x %x\n", dyn->d_tag, dyn->d_un.d_ptr );
#endif
        dyn++;
    }

    if( (!symtab) || (!strings) ) return NULL;

870 871 872 873 874 875 876 877 878 879 880 881 882 883 884 885 886 887 888 889
    if (gnu_hashtab)  /* new style hash table */
    {
        const unsigned int hash   = gnu_hash(var);
        const Elf32_Word nbuckets = gnu_hashtab[0];
        const Elf32_Word symbias  = gnu_hashtab[1];
        const Elf32_Word nwords   = gnu_hashtab[2];
        const ElfW(Addr) *bitmask = (const ElfW(Addr) *)(gnu_hashtab + 4);
        const Elf32_Word *buckets = (const Elf32_Word *)(bitmask + nwords);
        const Elf32_Word *chains  = buckets + nbuckets - symbias;

        if (!(idx = buckets[hash % nbuckets])) return NULL;
        do
        {
            if ((chains[idx] & ~1u) == (hash & ~1u) &&
                symtab[idx].st_info == ELF32_ST_INFO( STB_GLOBAL, type ) &&
                !wld_strcmp( strings + symtab[idx].st_name, var ))
                goto found;
        } while (!(chains[idx++] & 1u));
    }
    else if (hashtab)  /* old style hash table */
890
    {
891 892
        const unsigned int hash   = elf_hash(var);
        const Elf_Symndx nbuckets = hashtab[0];
893
        const Elf_Symndx *buckets = hashtab + 2;
894
        const Elf_Symndx *chains  = buckets + nbuckets;
895

896
        for (idx = buckets[hash % nbuckets]; idx != STN_UNDEF; idx = chains[idx])
897
        {
898
            if (symtab[idx].st_info == ELF32_ST_INFO( STB_GLOBAL, type ) &&
899
                !wld_strcmp( strings + symtab[idx].st_name, var ))
900
                goto found;
901 902 903
        }
    }
    return NULL;
904 905 906 907 908 909

found:
#ifdef DUMP_SYMS
    wld_printf("Found %s -> %x\n", strings + symtab[idx].st_name, symtab[idx].st_value );
#endif
    return (void *)symtab[idx].st_value;
910 911
}

912 913 914 915 916 917 918 919 920 921 922 923 924 925 926 927 928 929 930 931 932 933 934 935 936 937 938 939 940 941 942 943 944 945
/*
 *  preload_reserve
 *
 * Reserve a range specified in string format
 */
static void preload_reserve( const char *str )
{
    const char *p;
    unsigned long result = 0;
    void *start = NULL, *end = NULL;
    int first = 1;

    for (p = str; *p; p++)
    {
        if (*p >= '0' && *p <= '9') result = result * 16 + *p - '0';
        else if (*p >= 'a' && *p <= 'f') result = result * 16 + *p - 'a' + 10;
        else if (*p >= 'A' && *p <= 'F') result = result * 16 + *p - 'A' + 10;
        else if (*p == '-')
        {
            if (!first) goto error;
            start = (void *)(result & ~page_mask);
            result = 0;
            first = 0;
        }
        else goto error;
    }
    if (!first) end = (void *)((result + page_mask) & ~page_mask);
    else if (result) goto error;  /* single value '0' is allowed */

    /* sanity checks */
    if (end <= start) start = end = NULL;
    else if ((char *)end > preloader_start &&
             (char *)start <= preloader_end)
    {
946
        wld_printf( "WINEPRELOADRESERVE range %p-%p overlaps preloader %p-%p\n",
947 948 949 950
                     start, end, preloader_start, preloader_end );
        start = end = NULL;
    }

951 952 953 954 955 956
    /* check for overlap with low memory area */
    if ((char *)end <= (char *)preload_info[0].addr + preload_info[0].size)
        start = end = NULL;
    else if ((char *)start < (char *)preload_info[0].addr + preload_info[0].size)
        start = (char *)preload_info[0].addr + preload_info[0].size;

957 958 959 960 961 962 963 964 965
    /* entry 2 is for the PE exe */
    preload_info[2].addr = start;
    preload_info[2].size = (char *)end - (char *)start;
    return;

error:
    fatal_error( "invalid WINEPRELOADRESERVE value '%s'\n", str );
}

966 967 968 969 970 971 972 973 974 975 976 977 978 979 980 981 982 983 984 985 986 987 988 989 990
/* check if address is in one of the reserved ranges */
static int is_addr_reserved( const void *addr )
{
    int i;

    for (i = 0; preload_info[i].size; i++)
    {
        if ((const char *)addr >= (const char *)preload_info[i].addr &&
            (const char *)addr <  (const char *)preload_info[i].addr + preload_info[i].size)
            return 1;
    }
    return 0;
}

/* remove a range from the preload list */
static void remove_preload_range( int i )
{
    while (preload_info[i].size)
    {
        preload_info[i].addr = preload_info[i+1].addr;
        preload_info[i].size = preload_info[i+1].size;
        i++;
    }
}

991 992 993 994 995 996 997
/*
 *  is_in_preload_range
 *
 * Check if address of the given aux value is in one of the reserved ranges
 */
static int is_in_preload_range( const ElfW(auxv_t) *av, int type )
{
998
    while (av->a_type != AT_NULL)
999
    {
1000 1001
        if (av->a_type == type) return is_addr_reserved( (const void *)av->a_un.a_val );
        av++;
1002 1003 1004
    }
    return 0;
}
1005

1006 1007 1008
/* set the process name if supported */
static void set_process_name( int argc, char *argv[] )
{
1009 1010
    int i;
    unsigned int off;
1011 1012 1013 1014 1015 1016 1017 1018 1019 1020 1021 1022 1023 1024 1025 1026
    char *p, *name, *end;

    /* set the process short name */
    for (p = name = argv[1]; *p; p++) if (p[0] == '/' && p[1]) name = p + 1;
    if (wld_prctl( 15 /* PR_SET_NAME */, (int)name ) == -1) return;

    /* find the end of the argv array and move everything down */
    end = argv[argc - 1];
    while (*end) end++;
    off = argv[1] - argv[0];
    for (p = argv[1]; p <= end; p++) *(p - off) = *p;
    wld_memset( end - off, 0, off );
    for (i = 1; i < argc; i++) argv[i] -= off;
}


1027 1028 1029 1030 1031 1032 1033
/*
 *  wld_start
 *
 *  Repeat the actions the kernel would do when loading a dynamically linked .so
 *  Load the binary and then its ELF interpreter.
 *  Note, we assume that the binary is a dynamically linked ELF shared object.
 */
1034
void* wld_start( void **stack )
1035
{
1036
    int i, *pargc;
1037
    char **argv, **p;
1038
    char *interp, *reserve = NULL;
1039
    ElfW(auxv_t) new_av[12], delete_av[3], *av;
1040 1041 1042
    struct wld_link_map main_binary_map, ld_so_map;
    struct wine_preload_info **wine_main_preload_info;

1043 1044
    pargc = *stack;
    argv = (char **)pargc + 1;
1045
    if (*pargc < 2) fatal_error( "Usage: %s wine_binary [args]\n", argv[0] );
1046 1047

    /* skip over the parameters */
1048
    p = argv + *pargc + 1;
1049 1050

    /* skip over the environment */
1051 1052 1053
    while (*p)
    {
        static const char res[] = "WINEPRELOADRESERVE=";
1054
        if (!wld_strncmp( *p, res, sizeof(res)-1 )) reserve = *p + sizeof(res) - 1;
1055 1056
        p++;
    }
1057 1058

    av = (ElfW(auxv_t)*) (p+1);
1059
    page_size = get_auxiliary( av, AT_PAGESZ, 4096 );
1060 1061
    page_mask = page_size - 1;

1062 1063 1064
    preloader_start = (char *)_start - ((unsigned int)_start & page_mask);
    preloader_end = (char *)((unsigned int)(_end + page_mask) & ~page_mask);

1065
#ifdef DUMP_AUX_INFO
1066
    wld_printf( "stack = %p\n", *stack );
1067
    for( i = 0; i < *pargc; i++ ) wld_printf("argv[%x] = %s\n", i, argv[i]);
1068 1069 1070 1071
    dump_auxiliary( av );
#endif

    /* reserve memory that Wine needs */
1072
    if (reserve) preload_reserve( reserve );
1073
    for (i = 0; preload_info[i].size; i++)
1074 1075 1076 1077
    {
        if (wld_mmap( preload_info[i].addr, preload_info[i].size, PROT_NONE,
                      MAP_FIXED | MAP_PRIVATE | MAP_ANON | MAP_NORESERVE, -1, 0 ) == (void *)-1)
        {
1078
            wld_printf( "preloader: Warning: failed to reserve range %p-%p\n",
1079 1080 1081 1082 1083
                        preload_info[i].addr, (char *)preload_info[i].addr + preload_info[i].size );
            remove_preload_range( i );
            i--;
        }
    }
1084

1085 1086
    /* add an executable page at the top of the address space to defeat
     * broken no-exec protections that play with the code selector limit */
1087 1088
    if (is_addr_reserved( (char *)0x80000000 - page_size ))
        wld_mprotect( (char *)0x80000000 - page_size, page_size, PROT_EXEC | PROT_READ );
1089

1090
    /* load the main binary */
1091
    map_so_lib( argv[1], &main_binary_map );
1092 1093 1094 1095 1096 1097 1098

    /* load the ELF interpreter */
    interp = (char *)main_binary_map.l_addr + main_binary_map.l_interp;
    map_so_lib( interp, &ld_so_map );

    /* store pointer to the preload info into the appropriate main binary variable */
    wine_main_preload_info = find_symbol( main_binary_map.l_phdr, main_binary_map.l_phnum,
1099
                                          "wine_main_preload_info", STT_OBJECT );
1100 1101 1102
    if (wine_main_preload_info) *wine_main_preload_info = preload_info;
    else wld_printf( "wine_main_preload_info not found\n" );

1103 1104 1105 1106 1107 1108 1109 1110
#define SET_NEW_AV(n,type,val) new_av[n].a_type = (type); new_av[n].a_un.a_val = (val);
    SET_NEW_AV( 0, AT_PHDR, (unsigned long)main_binary_map.l_phdr );
    SET_NEW_AV( 1, AT_PHENT, sizeof(ElfW(Phdr)) );
    SET_NEW_AV( 2, AT_PHNUM, main_binary_map.l_phnum );
    SET_NEW_AV( 3, AT_PAGESZ, page_size );
    SET_NEW_AV( 4, AT_BASE, ld_so_map.l_addr );
    SET_NEW_AV( 5, AT_FLAGS, get_auxiliary( av, AT_FLAGS, 0 ) );
    SET_NEW_AV( 6, AT_ENTRY, main_binary_map.l_entry );
1111 1112 1113 1114
    SET_NEW_AV( 7, AT_UID, get_auxiliary( av, AT_UID, wld_getuid() ) );
    SET_NEW_AV( 8, AT_EUID, get_auxiliary( av, AT_EUID, wld_geteuid() ) );
    SET_NEW_AV( 9, AT_GID, get_auxiliary( av, AT_GID, wld_getgid() ) );
    SET_NEW_AV(10, AT_EGID, get_auxiliary( av, AT_EGID, wld_getegid() ) );
1115
    SET_NEW_AV(11, AT_NULL, 0 );
1116 1117
#undef SET_NEW_AV

1118 1119
    i = 0;
    /* delete sysinfo values if addresses conflict */
1120 1121 1122 1123 1124
    if (is_in_preload_range( av, AT_SYSINFO ) || is_in_preload_range( av, AT_SYSINFO_EHDR ))
    {
        delete_av[i++].a_type = AT_SYSINFO;
        delete_av[i++].a_type = AT_SYSINFO_EHDR;
    }
1125 1126
    delete_av[i].a_type = AT_NULL;

1127
    /* get rid of first argument */
1128
    set_process_name( *pargc, argv );
1129 1130 1131
    pargc[1] = pargc[0] - 1;
    *stack = pargc + 1;

1132
    set_auxiliary_values( av, new_av, delete_av, stack );
1133 1134

#ifdef DUMP_AUX_INFO
1135
    wld_printf("new stack = %p\n", *stack);
1136 1137 1138 1139 1140
    wld_printf("jumping to %x\n", ld_so_map.l_entry);
#endif

    return (void *)ld_so_map.l_entry;
}