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preloader.c
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/*
* Preloader for ld.so
*
* Copyright (C) 1995,96,97,98,99,2000,2001,2002 Free Software Foundation, Inc.
* Copyright (C) 2004 Mike McCormack for CodeWeavers
* 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
* Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA
*/
/*
* 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 <[email protected]>
* 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>
#ifdef HAVE_SYS_STAT_H
# include <sys/stat.h>
#endif
#include <fcntl.h>
#ifdef HAVE_SYS_MMAN_H
# include <sys/mman.h>
#endif
#ifdef HAVE_SYS_SYSCALL_H
# include <sys/syscall.h>
#endif
#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[] =
{
#ifdef __i386__
{ (void *)0x00000000, 0x00010000 }, /* low 64k */
{ (void *)0x00010000, 0x00100000 }, /* DOS area */
{ (void *)0x00110000, 0x67ef0000 }, /* low memory area */
{ (void *)0x7f000000, 0x03000000 }, /* top-down allocations + shared heap + virtual heap */
#else
{ (void *)0x000000010000, 0x00100000 }, /* DOS area */
{ (void *)0x000000110000, 0x67ef0000 }, /* low memory area */
{ (void *)0x00007ff00000, 0x000f0000 }, /* shared user data */
{ (void *)0x7ffffe000000, 0x01ff0000 }, /* top-down allocations + virtual heap */
#endif
{ 0, 0 }, /* PE exe range set with WINEPRELOADRESERVE */
{ 0, 0 } /* end of list */
};
/* debugging */
#undef DUMP_SEGMENTS
#undef DUMP_AUX_INFO
#undef DUMP_SYMS
#undef DUMP_MAPS
/* older systems may not define these */
#ifndef PT_TLS
#define PT_TLS 7
#endif
#ifndef AT_SYSINFO
#define AT_SYSINFO 32
#endif
#ifndef AT_SYSINFO_EHDR
#define AT_SYSINFO_EHDR 33
#endif
#ifndef DT_GNU_HASH
#define DT_GNU_HASH 0x6ffffef5
#endif
static size_t page_size, page_mask;
static char *preloader_start, *preloader_end;
struct wld_link_map {
ElfW(Addr) l_addr;
ElfW(Dyn) *l_ld;
ElfW(Phdr)*l_phdr;
ElfW(Addr) l_entry;
ElfW(Half) l_ldnum;
ElfW(Half) l_phnum;
ElfW(Addr) l_map_start, l_map_end;
ElfW(Addr) l_interp;
};
struct wld_auxv
{
ElfW(Addr) a_type;
union
{
ElfW(Addr) a_val;
} a_un;
};
/*
* 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.
*/
void __bb_init_func(void) { return; }
/* similar to the above but for -fstack-protector */
void *__stack_chk_guard = 0;
void __stack_chk_fail_local(void) { return; }
void __stack_chk_fail(void) { return; }
#ifdef __i386__
/* 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 usable : 1;
unsigned int garbage : 25;
} thread_ldt = { -1, (unsigned long)thread_data, 0xfffff, 1, 0, 0, 1, 0, 1, 0 };
/*
* The _start function is the entry and exit point of this program
*
* It calls wld_start, passing a pointer to the args it receives
* then jumps to the address wld_start returns.
*/
void _start(void);
extern char _end[];
__ASM_GLOBAL_FUNC(_start,
__ASM_CFI("\t.cfi_undefined %eip\n")
"\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"
"\tleal -136(%esp),%esp\n" /* allocate some space for extra aux values */
"\tpushl %eax\n" /* orig stack pointer */
"\tpushl %esp\n" /* ptr to orig stack pointer */
"\tcall wld_start\n"
"\tpopl %ecx\n" /* remove ptr to stack pointer */
"\tpopl %esp\n" /* new stack pointer */
"\tpush %eax\n" /* ELF interpreter entry point */
"\txor %eax,%eax\n"
"\txor %ecx,%ecx\n"
"\txor %edx,%edx\n"
"\tmov %ax,%gs\n" /* clear %gs again */
"\tret\n")
/* 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 */
__asm__ __volatile__( "pushl %%ebx; movl %1,%%ebx; int $0x80; popl %%ebx"
: : "a" (1 /* SYS_exit */), "r" (code) );
}
static inline int wld_open( const char *name, int flags )
{
int ret;
__asm__ __volatile__( "pushl %%ebx; movl %2,%%ebx; int $0x80; popl %%ebx"
: "=a" (ret) : "0" (5 /* SYS_open */), "r" (name), "c" (flags) );
return SYSCALL_RET(ret);
}
static inline int wld_close( int fd )
{
int ret;
__asm__ __volatile__( "pushl %%ebx; movl %2,%%ebx; int $0x80; popl %%ebx"
: "=a" (ret) : "0" (6 /* SYS_close */), "r" (fd) );
return SYSCALL_RET(ret);
}
static inline ssize_t wld_read( int fd, void *buffer, size_t len )
{
int ret;
__asm__ __volatile__( "pushl %%ebx; movl %2,%%ebx; int $0x80; popl %%ebx"
: "=a" (ret)
: "0" (3 /* SYS_read */), "r" (fd), "c" (buffer), "d" (len)
: "memory" );
return SYSCALL_RET(ret);
}
static inline ssize_t wld_write( int fd, const void *buffer, size_t len )
{
int ret;
__asm__ __volatile__( "pushl %%ebx; movl %2,%%ebx; int $0x80; popl %%ebx"
: "=a" (ret) : "0" (4 /* SYS_write */), "r" (fd), "c" (buffer), "d" (len) );
return SYSCALL_RET(ret);
}
static inline int wld_mprotect( const void *addr, size_t len, int prot )
{
int ret;
__asm__ __volatile__( "pushl %%ebx; movl %2,%%ebx; int $0x80; popl %%ebx"
: "=a" (ret) : "0" (125 /* SYS_mprotect */), "r" (addr), "c" (len), "d" (prot) );
return SYSCALL_RET(ret);
}
void *wld_mmap( void *start, size_t len, int prot, int flags, int fd, unsigned int offset );
__ASM_GLOBAL_FUNC(wld_mmap,
"\tpushl %ebp\n"
__ASM_CFI(".cfi_adjust_cfa_offset 4\n\t")
"\tpushl %ebx\n"
__ASM_CFI(".cfi_adjust_cfa_offset 4\n\t")
"\tpushl %esi\n"
__ASM_CFI(".cfi_adjust_cfa_offset 4\n\t")
"\tpushl %edi\n"
__ASM_CFI(".cfi_adjust_cfa_offset 4\n\t")
"\tmovl $192,%eax\n" /* SYS_mmap2 */
"\tmovl 20(%esp),%ebx\n" /* start */
"\tmovl 24(%esp),%ecx\n" /* len */
"\tmovl 28(%esp),%edx\n" /* prot */
"\tmovl 32(%esp),%esi\n" /* flags */
"\tmovl 36(%esp),%edi\n" /* fd */
"\tmovl 40(%esp),%ebp\n" /* offset */
"\tshrl $12,%ebp\n"
"\tint $0x80\n"
"\tcmpl $-4096,%eax\n"
"\tjbe 2f\n"
"\tcmpl $-38,%eax\n" /* ENOSYS */
"\tjne 1f\n"
"\tmovl $90,%eax\n" /* SYS_mmap */
"\tleal 20(%esp),%ebx\n"
"\tint $0x80\n"
"\tcmpl $-4096,%eax\n"
"\tjbe 2f\n"
"1:\tmovl $-1,%eax\n"
"2:\tpopl %edi\n"
__ASM_CFI(".cfi_adjust_cfa_offset -4\n\t")
"\tpopl %esi\n"
__ASM_CFI(".cfi_adjust_cfa_offset -4\n\t")
"\tpopl %ebx\n"
__ASM_CFI(".cfi_adjust_cfa_offset -4\n\t")
"\tpopl %ebp\n"
__ASM_CFI(".cfi_adjust_cfa_offset -4\n\t")
"\tret\n" )
static inline uid_t wld_getuid(void)
{
uid_t ret;
__asm__( "int $0x80" : "=a" (ret) : "0" (24 /* SYS_getuid */) );
return ret;
}
static inline uid_t wld_geteuid(void)
{
uid_t ret;
__asm__( "int $0x80" : "=a" (ret) : "0" (49 /* SYS_geteuid */) );
return ret;
}
static inline gid_t wld_getgid(void)
{
gid_t ret;
__asm__( "int $0x80" : "=a" (ret) : "0" (47 /* SYS_getgid */) );
return ret;
}
static inline gid_t wld_getegid(void)
{
gid_t ret;
__asm__( "int $0x80" : "=a" (ret) : "0" (50 /* SYS_getegid */) );
return ret;
}
static inline int wld_prctl( int code, long arg )
{
int ret;
__asm__ __volatile__( "pushl %%ebx; movl %2,%%ebx; int $0x80; popl %%ebx"
: "=a" (ret) : "0" (172 /* SYS_prctl */), "r" (code), "c" (arg) );
return SYSCALL_RET(ret);
}
#elif defined(__x86_64__)
void *thread_data[256];
/*
* The _start function is the entry and exit point of this program
*
* It calls wld_start, passing a pointer to the args it receives
* then jumps to the address wld_start returns.
*/
void _start(void);
extern char _end[];
__ASM_GLOBAL_FUNC(_start,
__ASM_CFI(".cfi_undefined %rip\n\t")
"movq %rsp,%rax\n\t"
"leaq -144(%rsp),%rsp\n\t" /* allocate some space for extra aux values */
"movq %rax,(%rsp)\n\t" /* orig stack pointer */
"movq $thread_data,%rsi\n\t"
"movq $0x1002,%rdi\n\t" /* ARCH_SET_FS */
"movq $158,%rax\n\t" /* SYS_arch_prctl */
"syscall\n\t"
"movq %rsp,%rdi\n\t" /* ptr to orig stack pointer */
"call wld_start\n\t"
"movq (%rsp),%rsp\n\t" /* new stack pointer */
"pushq %rax\n\t" /* ELF interpreter entry point */
"xorq %rax,%rax\n\t"
"xorq %rcx,%rcx\n\t"
"xorq %rdx,%rdx\n\t"
"xorq %rsi,%rsi\n\t"
"xorq %rdi,%rdi\n\t"
"xorq %r8,%r8\n\t"
"xorq %r9,%r9\n\t"
"xorq %r10,%r10\n\t"
"xorq %r11,%r11\n\t"
"ret")
#define SYSCALL_FUNC( name, nr ) \
__ASM_GLOBAL_FUNC( name, \
"movq $" #nr ",%rax\n\t" \
"movq %rcx,%r10\n\t" \
"syscall\n\t" \
"leaq 4096(%rax),%rcx\n\t" \
"movq $-1,%rdx\n\t" \
"cmp $4096,%rcx\n\t" \
"cmovb %rdx,%rax\n\t" \
"ret" )
#define SYSCALL_NOERR( name, nr ) \
__ASM_GLOBAL_FUNC( name, \
"movq $" #nr ",%rax\n\t" \
"syscall\n\t" \
"ret" )
void wld_exit( int code ) __attribute__((noreturn));
SYSCALL_NOERR( wld_exit, 60 /* SYS_exit */ );
ssize_t wld_read( int fd, void *buffer, size_t len );
SYSCALL_FUNC( wld_read, 0 /* SYS_read */ );
ssize_t wld_write( int fd, const void *buffer, size_t len );
SYSCALL_FUNC( wld_write, 1 /* SYS_write */ );
int wld_open( const char *name, int flags );
SYSCALL_FUNC( wld_open, 2 /* SYS_open */ );
int wld_close( int fd );
SYSCALL_FUNC( wld_close, 3 /* SYS_close */ );
void *wld_mmap( void *start, size_t len, int prot, int flags, int fd, off_t offset );
SYSCALL_FUNC( wld_mmap, 9 /* SYS_mmap */ );
int wld_mprotect( const void *addr, size_t len, int prot );
SYSCALL_FUNC( wld_mprotect, 10 /* SYS_mprotect */ );
int wld_prctl( int code, long arg );
SYSCALL_FUNC( wld_prctl, 157 /* SYS_prctl */ );
uid_t wld_getuid(void);
SYSCALL_NOERR( wld_getuid, 102 /* SYS_getuid */ );
gid_t wld_getgid(void);
SYSCALL_NOERR( wld_getgid, 104 /* SYS_getgid */ );
uid_t wld_geteuid(void);
SYSCALL_NOERR( wld_geteuid, 107 /* SYS_geteuid */ );
gid_t wld_getegid(void);
SYSCALL_NOERR( wld_getegid, 108 /* SYS_getegid */ );
#elif defined(__aarch64__)
void *thread_data[256];
/*
* The _start function is the entry and exit point of this program
*
* It calls wld_start, passing a pointer to the args it receives
* then jumps to the address wld_start returns.
*/
void _start(void);
extern char _end[];
__ASM_GLOBAL_FUNC(_start,
"mov x0, SP\n\t"
"sub SP, SP, #144\n\t" /* allocate some space for extra aux values */
"str x0, [SP]\n\t" /* orig stack pointer */
"ldr x0, =thread_data\n\t"
"msr tpidr_el0, x0\n\t"
"mov x0, SP\n\t" /* ptr to orig stack pointer */
"bl wld_start\n\t"
"ldr x1, [SP]\n\t" /* new stack pointer */
"mov SP, x1\n\t"
"mov x30, x0\n\t"
"mov x0, #0\n\t"
"mov x1, #0\n\t"
"mov x2, #0\n\t"
"mov x3, #0\n\t"
"mov x4, #0\n\t"
"mov x5, #0\n\t"
"mov x6, #0\n\t"
"mov x7, #0\n\t"
"mov x8, #0\n\t"
"mov x9, #0\n\t"
"mov x10, #0\n\t"
"mov x11, #0\n\t"
"mov x12, #0\n\t"
"mov x13, #0\n\t"
"mov x14, #0\n\t"
"mov x15, #0\n\t"
"mov x16, #0\n\t"
"mov x17, #0\n\t"
"mov x18, #0\n\t"
"ret")
#define SYSCALL_FUNC( name, nr ) \
__ASM_GLOBAL_FUNC( name, \
"stp x8, x9, [SP, #-16]!\n\t" \
"mov x8, #" #nr "\n\t" \
"svc #0\n\t" \
"ldp x8, x9, [SP], #16\n\t" \
"cmn x0, #1, lsl#12\n\t" \
"cinv x0, x0, hi\n\t" \
"b.hi 1f\n\t" \
"ret\n\t" \
"1: mov x0, #-1\n\t" \
"ret" )
#define SYSCALL_NOERR( name, nr ) \
__ASM_GLOBAL_FUNC( name, \
"stp x8, x9, [SP, #-16]!\n\t" \
"mov x8, #" #nr "\n\t" \
"svc #0\n\t" \
"ldp x8, x9, [SP], #16\n\t" \
"ret" )
void wld_exit( int code ) __attribute__((noreturn));
SYSCALL_NOERR( wld_exit, 93 /* SYS_exit */ );
ssize_t wld_read( int fd, void *buffer, size_t len );
SYSCALL_FUNC( wld_read, 63 /* SYS_read */ );
ssize_t wld_write( int fd, const void *buffer, size_t len );
SYSCALL_FUNC( wld_write, 64 /* SYS_write */ );
int wld_openat( int dirfd, const char *name, int flags );
SYSCALL_FUNC( wld_openat, 56 /* SYS_openat */ );
int wld_open( const char *name, int flags )
{
return wld_openat(-100 /* AT_FDCWD */, name, flags);
}
int wld_close( int fd );
SYSCALL_FUNC( wld_close, 57 /* SYS_close */ );
void *wld_mmap( void *start, size_t len, int prot, int flags, int fd, off_t offset );
SYSCALL_FUNC( wld_mmap, 222 /* SYS_mmap */ );
int wld_mprotect( const void *addr, size_t len, int prot );
SYSCALL_FUNC( wld_mprotect, 226 /* SYS_mprotect */ );
int wld_prctl( int code, long arg );
SYSCALL_FUNC( wld_prctl, 167 /* SYS_prctl */ );
uid_t wld_getuid(void);
SYSCALL_NOERR( wld_getuid, 174 /* SYS_getuid */ );
gid_t wld_getgid(void);
SYSCALL_NOERR( wld_getgid, 176 /* SYS_getgid */ );
uid_t wld_geteuid(void);
SYSCALL_NOERR( wld_geteuid, 175 /* SYS_geteuid */ );
gid_t wld_getegid(void);
SYSCALL_NOERR( wld_getegid, 177 /* SYS_getegid */ );
#else
#error preloader not implemented for this CPU
#endif
/* 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;
}
/*
* wld_printf - just the basics
*
* %x prints a hex number
* %s prints a string
* %p prints a pointer
*/
static int wld_vsprintf(char *buffer, const char *fmt, va_list args )
{
static const char hex_chars[16] = "0123456789abcdef";
const char *p = fmt;
char *str = buffer;
int i;
while( *p )
{
if( *p == '%' )
{
p++;
if( *p == 'x' )
{
unsigned int x = va_arg( args, unsigned int );
for (i = 2*sizeof(x) - 1; i >= 0; i--)
*str++ = hex_chars[(x>>(i*4))&0xf];
}
else if (p[0] == 'l' && p[1] == 'x')
{
unsigned long x = va_arg( args, unsigned long );
for (i = 2*sizeof(x) - 1; 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 = 2*sizeof(x) - 1; i >= 0; i--)
*str++ = hex_chars[(x>>(i*4))&0xf];
}
else if( *p == 's' )
{
char *s = va_arg( args, char * );
while(*s)
*str++ = *s++;
}
else if( *p == 0 )
break;
p++;
}
*str++ = *p++;
}
*str = 0;
return str - buffer;
}
static __attribute__((format(printf,1,2))) void wld_printf(const char *fmt, ... )
{
va_list args;
char buffer[256];
int len;
va_start( args, fmt );
len = wld_vsprintf(buffer, fmt, args );
va_end( args );
wld_write(2, buffer, len);
}
static __attribute__((noreturn,format(printf,1,2))) void fatal_error(const char *fmt, ... )
{
va_list args;
char buffer[256];
int len;
va_start( args, fmt );
len = wld_vsprintf(buffer, fmt, args );
va_end( args );
wld_write(2, buffer, len);
wld_exit(1);
}
#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( struct wld_auxv *av )
{
#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),
NAME(AT_SYSINFO),
NAME(AT_SYSINFO_EHDR),
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;
if (names[i].name) wld_printf("%s = %lx\n", names[i].name, (unsigned long)av->a_un.a_val);
else wld_printf( "%lx = %lx\n", (unsigned long)av->a_type, (unsigned long)av->a_un.a_val );
}
}
#endif
/*
* set_auxiliary_values
*
* Set the new auxiliary values
*/
static void set_auxiliary_values( struct wld_auxv *av, const struct wld_auxv *new_av,
const struct wld_auxv *delete_av, void **stack )
{
int i, j, av_count = 0, new_count = 0, delete_count = 0;
char *src, *dst;
/* count how many aux values we have already */
while (av[av_count].a_type != AT_NULL) av_count++;
/* 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;
}
}
/* 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++)
{
for (i = 0; i < av_count; i++) if (av[i].a_type == new_av[j].a_type) break;
if (i == av_count) new_count++;
}
src = (char *)*stack;
dst = src - (new_count - delete_count) * sizeof(*av);
dst = (char *)((unsigned long)dst & ~15);
if (dst < src) /* 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 (dst > src) /* get rid of unused values */
{
int len = (char *)(av + av_count + 1) - src;
for (i = len - 1; i >= 0; i--) dst[i] = src[i];
}
*stack = dst;
av = (struct wld_auxv *)((char *)av + (dst - src));
/* 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
}
/*
* get_auxiliary
*
* Get a field of the auxiliary structure
*/
static int get_auxiliary( struct wld_auxv *av, int type, int def_val )
{
for ( ; av->a_type != AT_NULL; av++)
if( av->a_type == type ) return av->a_un.a_val;
return def_val;
}
/*
* 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;
fd = wld_open( name, O_RDONLY );
if (fd == -1) fatal_error("%s: could not open\n", name );
if (wld_read( fd, buf, sizeof(buf) ) != sizeof(buf))
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 );
#ifdef __i386__
if( header->e_machine != EM_386 )
fatal_error("%s: not an i386 ELF binary... don't know how to load it\n", name );
#elif defined(__x86_64__)
if( header->e_machine != EM_X86_64 )
fatal_error("%s: not an x86-64 ELF binary... don't know how to load it\n", name );
#elif defined(__aarch64__)
if( header->e_machine != EM_AARCH64 )
fatal_error("%s: not an aarch64 ELF binary... don't know how to load it\n", name );
#endif
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
wld_printf( "ph = %p\n", ph );
wld_printf( " p_type = %lx\n", (unsigned long)ph->p_type );
wld_printf( " p_flags = %lx\n", (unsigned long)ph->p_flags );
wld_printf( " p_offset = %lx\n", (unsigned long)ph->p_offset );
wld_printf( " p_vaddr = %lx\n", (unsigned long)ph->p_vaddr );
wld_printf( " p_paddr = %lx\n", (unsigned long)ph->p_paddr );
wld_printf( " p_filesz = %lx\n", (unsigned long)ph->p_filesz );
wld_printf( " p_memsz = %lx\n", (unsigned long)ph->p_memsz );
wld_printf( " p_align = %lx\n", (unsigned long)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. */
if (!nloadcmds)
fatal_error( "%s: no segments to load\n", name );
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. */
l->l_map_start = (ElfW(Addr)) wld_mmap ((void *) mappref, maplength,
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;
wld_mprotect ((caddr_t) (l->l_addr + c->mapend),
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)
fatal_error( "%s: binary overlaps preloader (%p-%p)\n",
name, (char *)c->mapstart, (char *)c->mapstart + maplength );
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. */
wld_mmap ((void *) (l->l_addr + c->mapstart),
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 long)(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)