static int load_elf_binary(struct linux_binprm * bprm, struct pt_regs * regs)
{
struct elfhdr elf_ex;
struct elfhdr interp_elf_ex;
struct file * file;
struct exec interp_ex;
struct inode *interpreter_inode;
unsigned int load_addr;
unsigned int interpreter_type = INTERPRETER_NONE;
int i;
int old_fs;
int error;
struct elf_phdr * elf_ppnt, *elf_phdata;
int elf_exec_fileno;
unsigned int elf_bss, k, elf_brk;
int retval;
char * elf_interpreter;
unsigned int elf_entry;
int status;
unsigned int start_code, end_code, end_data;
unsigned int elf_stack;
char passed_fileno[6];
status = 0;
load_addr = 0;
elf_ex = *((struct elfhdr *) bprm->buf); /* exec-header */
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_machine != EM_386 && elf_ex.e_machine != EM_486) ||
(!bprm->inode->i_op || !bprm->inode->i_op->default_file_ops ||
!bprm->inode->i_op->default_file_ops->mmap)){
return -ENOEXEC;
};
/* Now read in all of the header information */
elf_phdata = (struct elf_phdr *) kmalloc(elf_ex.e_phentsize *
elf_ex.e_phnum, GFP_KERNEL);
old_fs = get_fs();
set_fs(get_ds());
retval = read_exec(bprm->inode, elf_ex.e_phoff, (char *) elf_phdata,
elf_ex.e_phentsize * elf_ex.e_phnum);
set_fs(old_fs);
if (retval < 0) {
kfree (elf_phdata);
return retval;
}
elf_ppnt = elf_phdata;
elf_bss = 0;
elf_brk = 0;
elf_exec_fileno = open_inode(bprm->inode, O_RDONLY);
if (elf_exec_fileno < 0) {
kfree (elf_phdata);
return elf_exec_fileno;
}
file = current->files->fd[elf_exec_fileno];
elf_stack = 0xffffffff;
elf_interpreter = NULL;
start_code = 0;
end_code = 0;
end_data = 0;
old_fs = get_fs();
set_fs(get_ds());
for(i=0;i < elf_ex.e_phnum; i++){
if(elf_ppnt->p_type == PT_INTERP) {
/* This is the program interpreter used for shared libraries -
for now assume that this is an a.out format binary */
elf_interpreter = (char *) kmalloc(elf_ppnt->p_filesz,
GFP_KERNEL);
retval = read_exec(bprm->inode,elf_ppnt->p_offset,elf_interpreter,
elf_ppnt->p_filesz);
#if 0
printk("Using ELF interpreter %s\n", elf_interpreter);
#endif
if(retval >= 0)
retval = namei(elf_interpreter, &interpreter_inode);
if(retval >= 0)
retval = read_exec(interpreter_inode,0,bprm->buf,128);
if(retval >= 0){
interp_ex = *((struct exec *) bprm->buf); /* exec-header */
interp_elf_ex = *((struct elfhdr *) bprm->buf); /* exec-header */
};
if(retval < 0) {
kfree (elf_phdata);
kfree(elf_interpreter);
return retval;
};
};
elf_ppnt++;
};
set_fs(old_fs);
/* Some simple consistency checks for the interpreter */
if(elf_interpreter){
interpreter_type = INTERPRETER_ELF | INTERPRETER_AOUT;
if(retval < 0) {
kfree(elf_interpreter);
kfree(elf_phdata);
return -ELIBACC;
};
/* 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)
{
kfree(elf_interpreter);
kfree(elf_phdata);
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", elf_exec_fileno);
passed_p = passed_fileno;
if(elf_interpreter) {
bprm->p = copy_strings(1,&passed_p,bprm->page,bprm->p,2);
bprm->argc++;
};
};
if (!bprm->p) {
if(elf_interpreter) {
kfree(elf_interpreter);
}
kfree (elf_phdata);
return -E2BIG;
}
}
/* OK, This is the point of no return */
flush_old_exec(bprm);
current->mm->end_data = 0;
current->mm->end_code = 0;
current->mm->start_mmap = ELF_START_MMAP;
current->mm->mmap = NULL;
elf_entry = (unsigned int) elf_ex.e_entry;
/* Do this so that we can load the interpreter, if need be. We will
change some of these later */
current->mm->rss = 0;
bprm->p += change_ldt(0, bprm->page);
current->mm->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. */
old_fs = get_fs();
set_fs(get_ds());
elf_ppnt = elf_phdata;
for(i=0;i < elf_ex.e_phnum; i++){
if(elf_ppnt->p_type == PT_INTERP) {
/* Set these up so that we are able to load the interpreter */
/* Now load the interpreter into user address space */
set_fs(old_fs);
if(interpreter_type & 1) elf_entry =
load_aout_interp(&interp_ex, interpreter_inode);
if(interpreter_type & 2) elf_entry =
load_elf_interp(&interp_elf_ex, interpreter_inode);
old_fs = get_fs();
set_fs(get_ds());
iput(interpreter_inode);
kfree(elf_interpreter);
if(elf_entry == 0xffffffff) {
printk("Unable to load interpreter\n");
kfree(elf_phdata);
send_sig(SIGSEGV, current, 0);
return 0;
};
};
if(elf_ppnt->p_type == PT_LOAD) {
error = do_mmap(file,
elf_ppnt->p_vaddr & 0xfffff000,
elf_ppnt->p_filesz + (elf_ppnt->p_vaddr & 0xfff),
PROT_READ | PROT_WRITE | PROT_EXEC,
MAP_FIXED | MAP_PRIVATE,
elf_ppnt->p_offset & 0xfffff000);
#ifdef LOW_ELF_STACK
if(elf_ppnt->p_vaddr & 0xfffff000 < elf_stack)
elf_stack = elf_ppnt->p_vaddr & 0xfffff000;
#endif
if(!load_addr)
load_addr = elf_ppnt->p_vaddr - elf_ppnt->p_offset;
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((elf_ppnt->p_flags | PROT_WRITE) && end_code < k)
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;
};
elf_ppnt++;
};
set_fs(old_fs);
kfree(elf_phdata);
if(interpreter_type != INTERPRETER_AOUT) sys_close(elf_exec_fileno);
/* The following 3 lines need a little bit of work if we are loading
an iBCS2 binary. We should initially load it this way, and if
we get a lcall7, then we should look to see if the iBCS2 execution
profile is present. If it is, then switch to that, otherwise
bomb. */
current->personality = PER_LINUX;
current->lcall7 = no_lcall7;
current->signal_map = current->signal_invmap = ident_map;
current->executable = bprm->inode;
bprm->inode->i_count++;
#ifdef LOW_ELF_STACK
current->start_stack = p = elf_stack - 4;
#endif
bprm->p -= MAX_ARG_PAGES*PAGE_SIZE;
bprm->p = (unsigned long)
create_elf_tables((char *)bprm->p,
bprm->argc,
bprm->envc,
(interpreter_type == INTERPRETER_ELF ? &elf_ex : NULL),
load_addr,
(interpreter_type == INTERPRETER_AOUT ? 0 : 1));
if(interpreter_type == INTERPRETER_AOUT)
current->mm->arg_start += strlen(passed_fileno) + 1;
current->mm->start_brk = current->mm->brk = elf_brk;
current->mm->end_code = end_code;
current->mm->start_code = start_code;
current->mm->end_data = end_data;
current->mm->start_stack = bprm->p;
current->suid = current->euid = bprm->e_uid;
current->sgid = current->egid = bprm->e_gid;
/* Calling sys_brk effectively mmaps the pages that we need for the bss and break
sections */
current->mm->brk = (elf_bss + 0xfff) & 0xfffff000;
sys_brk((elf_brk + 0xfff) & 0xfffff000);
padzero(elf_bss);
/* 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. */
error = do_mmap(NULL, 0, 4096, PROT_READ | PROT_EXEC,
MAP_FIXED | MAP_PRIVATE, 0);
regs->eip = elf_entry; /* eip, magic happens :-) */
regs->esp = bprm->p; /* stack pointer */
if (current->flags & PF_PTRACED)
send_sig(SIGTRAP, current, 0);
return 0;
}
static int
load_object (struct linux_binprm * bprm, struct pt_regs *regs, int lib_ok)
{
COFF_FILHDR *coff_hdr = (COFF_FILHDR *) bprm->buf; /* COFF Header */
COFF_SCNHDR *sect_bufr; /* Pointer to section table */
COFF_SCNHDR *text_sect; /* Pointer to the text section */
COFF_SCNHDR *data_sect; /* Pointer to the data section */
COFF_SCNHDR *bss_sect; /* Pointer to the bss section */
int text_count; /* Number of text sections */
int data_count; /* Number of data sections */
int bss_count; /* Number of bss sections */
int lib_count; /* Number of lib sections */
unsigned int start_addr = 0;/* Starting location for program */
int status = 0; /* Result status register */
int fd = -1; /* Open file descriptor */
struct file *fp = NULL; /* Pointer to the file at "fd" */
short int sections = 0; /* Number of sections in the file */
short int aout_size = 0; /* Size of the a.out header area */
short int flags; /* Flag bits from the COFF header */
#ifdef COFF_DEBUG
printk ("binfmt_coff entry: %s\n", bprm->filename);
#endif
/*
* Validate the magic value for the object file.
*/
do {
if (COFF_I386BADMAG (*coff_hdr)) {
#ifdef COFF_DEBUG
printk ("bad filehdr magic\n");
#endif
status = -ENOEXEC;
break;
}
/*
* The object file should have 32 BIT little endian format. Do not allow
* it to have the 16 bit object file flag set as Linux is not able to run
* on the 80286/80186/8086.
*/
flags = COFF_SHORT (coff_hdr->f_flags);
if ((flags & (COFF_F_AR32WR | COFF_F_AR16WR)) != COFF_F_AR32WR) {
#ifdef COFF_DEBUG
printk ("invalid f_flags bits\n");
#endif
status = -ENOEXEC;
break;
}
/*
* Extract the header information which we need.
*/
sections = COFF_SHORT (coff_hdr->f_nscns); /* Number of sections */
aout_size = COFF_SHORT (coff_hdr->f_opthdr); /* Size of opt. headr */
/*
* If the file is not executable then reject the execution. This means
* that there must not be external references.
*/
if ((flags & COFF_F_EXEC) == 0) {
#ifdef COFF_DEBUG
printk ("not executable bit\n");
#endif
status = -ENOEXEC;
break;
}
/*
* There must be at least one section.
*/
if (sections == 0) {
#ifdef COFF_DEBUG
printk ("no sections\n");
#endif
status = -ENOEXEC;
break;
}
/*
* Do some additional consistency checks.
* The system requires mapping for this loader. If you try
* to use a file system with no mapping, the format is not valid.
*/
if (!bprm->inode->i_op ||
!bprm->inode->i_op->default_file_ops->mmap) {
#ifdef COFF_DEBUG
printk ("no mmap in fs\n");
#endif
status = -ENOEXEC;
}
}
while (0);
/*
* Allocate a buffer to hold the entire coff section list.
*/
if (status >= 0) {
int nbytes = sections * COFF_SCNHSZ;
sect_bufr = (COFF_SCNHDR *) kmalloc (nbytes, GFP_KERNEL);
if (0 == sect_bufr) {
#ifdef COFF_DEBUG
printk ("kmalloc failed\n");
#endif
status = -ENOEXEC;
}
/*
* Read the section list from the disk file.
*/
else {
int old_fs = get_fs ();
set_fs (get_ds ()); /* Make it point to the proper location */
status = read_exec (bprm->inode, /* INODE for file */
aout_size + COFF_FILHSZ, /* Offset in the file */
(char *) sect_bufr, /* Buffer for read */
nbytes); /* Byte count reqd. */
set_fs (old_fs); /* Restore the selector */
#ifdef COFF_DEBUG
if (status < 0)
printk ("read aout hdr, status = %d\n", status);
#endif
}
}
else
sect_bufr = NULL; /* Errors do not have a section buffer */
/*
* Count the number of sections for the required types and store the location
* of the last section for the three primary types.
*/
text_count = 0;
data_count = 0;
bss_count = 0;
lib_count = 0;
text_sect = NULL;
data_sect = NULL;
bss_sect = NULL;
/*
* Loop through the sections and find the various types
*/
if (status >= 0) {
int nIndex;
COFF_SCNHDR *sect_ptr = sect_bufr;
for (nIndex = 0; nIndex < sections; ++nIndex) {
long int sect_flags = COFF_LONG (sect_ptr->s_flags);
switch (sect_flags) {
case COFF_STYP_TEXT:
text_sect = sect_ptr;
++text_count;
status = is_properly_aligned (sect_ptr);
break;
case COFF_STYP_DATA:
data_sect = sect_ptr;
++data_count;
status = is_properly_aligned (sect_ptr);
break;
case COFF_STYP_BSS:
bss_sect = sect_ptr;
++bss_count;
break;
case COFF_STYP_LIB:
#ifdef COFF_DEBUG
printk (".lib section found\n");
#endif
++lib_count;
break;
default:
break;
}
sect_ptr = (COFF_SCNHDR *) & ((char *) sect_ptr)[COFF_SCNHSZ];
}
/*
* Ensure that there are the required sections. There must be one text
* sections and one each of the data and bss sections for an executable.
* A library may or may not have a data / bss section.
*/
if (text_count != 1) {
status = -ENOEXEC;
#ifdef COFF_DEBUG
printk ("no text sections\n");
#endif
}
else {
if (lib_ok) {
if (data_count != 1 || bss_count != 1) {
status = -ENOEXEC;
#ifdef COFF_DEBUG
printk ("no .data nor .bss sections\n");
#endif
}
}
}
}
/*
* If there is no additional header then assume the file starts at
* the first byte of the text section. This may not be the proper place,
* so the best solution is to include the optional header. A shared library
* __MUST__ have an optional header to indicate that it is a shared library.
*/
if (status >= 0) {
if (aout_size == 0) {
if (!lib_ok) {
status = -ENOEXEC;
#ifdef COFF_DEBUG
printk ("no header in library\n");
#endif
}
start_addr = COFF_LONG (text_sect->s_vaddr);
}
/*
* There is some header. Ensure that it is sufficient.
*/
else {
if (aout_size < COFF_AOUTSZ) {
status = -ENOEXEC;
#ifdef COFF_DEBUG
printk ("header too small\n");
#endif
}
else {
COFF_AOUTHDR *aout_hdr = /* Pointer to a.out header */
(COFF_AOUTHDR *) & ((char *) coff_hdr)[COFF_FILHSZ];
short int aout_magic = COFF_SHORT (aout_hdr->magic); /* id */
/*
* Validate the magic number in the a.out header. If it is valid then
* update the starting symbol location. Do not accept these file formats
* when loading a shared library.
*/
switch (aout_magic) {
case COFF_OMAGIC:
case COFF_ZMAGIC:
case COFF_STMAGIC:
if (!lib_ok) {
status = -ENOEXEC;
#ifdef COFF_DEBUG
printk ("wrong a.out header magic\n");
#endif
}
start_addr = (unsigned int) COFF_LONG (aout_hdr->entry);
break;
/*
* Magic value for a shared library. This is valid only when loading a
* shared library. (There is no need for a start_addr. It won't be used.)
*/
case COFF_SHMAGIC:
if (lib_ok) {
#ifdef COFF_DEBUG
printk ("wrong a.out header magic\n");
#endif
status = -ENOEXEC;
}
break;
default:
#ifdef COFF_DEBUG
printk ("wrong a.out header magic\n");
#endif
status = -ENOEXEC;
break;
}
}
}
}
/*
* Fetch a file pointer to the executable.
*/
if (status >= 0) {
fd = open_inode (bprm->inode, O_RDONLY);
if (fd < 0) {
#ifdef COFF_DEBUG
printk ("can not open inode, result = %d\n", fd);
#endif
status = fd;
}
else
fp = current->files->fd[fd];
}
else
fd = -1; /* Invalidate the open file descriptor */
/*
* Generate the proper values for the text fields
*
* THIS IS THE POINT OF NO RETURN. THE NEW PROCESS WILL TRAP OUT SHOULD
* SOMETHING FAIL IN THE LOAD SEQUENCE FROM THIS POINT ONWARD.
*/
if (status >= 0) {
long text_scnptr = COFF_LONG (text_sect->s_scnptr);
long text_size = COFF_LONG (text_sect->s_size);
long text_vaddr = COFF_LONG (text_sect->s_vaddr);
long data_scnptr;
long data_size;
long data_vaddr;
long bss_size;
long bss_vaddr;
/*
* Generate the proper values for the data fields
*/
if (data_sect != NULL) {
data_scnptr = COFF_LONG (data_sect->s_scnptr);
data_size = COFF_LONG (data_sect->s_size);
data_vaddr = COFF_LONG (data_sect->s_vaddr);
}
else {
data_scnptr = 0;
data_size = 0;
data_vaddr = 0;
}
/*
* Generate the proper values for the bss fields
*/
if (bss_sect != NULL) {
bss_size = COFF_LONG (bss_sect->s_size);
bss_vaddr = COFF_LONG (bss_sect->s_vaddr);
}
else {
bss_size = 0;
bss_vaddr = 0;
}
/*
* Flush the executable from memory. At this point the executable is
* committed to being defined or a segmentation violation will occur.
*/
if (lib_ok) {
#ifdef COFF_DEBUG
printk ("flushing executable\n");
#endif
flush_old_exec (bprm);
/*
* Define the initial locations for the various items in the new process
*/
current->mm->mmap = NULL;
current->mm->rss = 0;
/*
* Construct the parameter and environment string table entries.
*/
bprm->p += change_ldt (0, bprm->page);
bprm->p -= MAX_ARG_PAGES*PAGE_SIZE;
bprm->p = (unsigned long) create_tables ((char *) bprm->p,
bprm->argc,
bprm->envc,
1);
/*
* Do the end processing once the stack has been constructed
*/
current->mm->start_code = text_vaddr & PAGE_MASK;
current->mm->end_code = text_vaddr + text_size;
current->mm->end_data = data_vaddr + data_size;
current->mm->start_brk =
current->mm->brk = bss_vaddr + bss_size;
current->suid =
current->euid = bprm->e_uid;
current->sgid =
current->egid = bprm->e_gid;
current->executable = bprm->inode; /* Store inode for file */
++bprm->inode->i_count; /* Count the open inode */
regs->eip = start_addr; /* Current EIP register */
regs->esp =
current->mm->start_stack = bprm->p;
}
/*
* Map the text pages
*/
#ifdef COFF_DEBUG
printk (".text: vaddr = %d, size = %d, scnptr = %d\n",
text_vaddr,
text_size,
text_scnptr);
#endif
status = do_mmap (fp,
text_vaddr & PAGE_MASK,
text_size + (text_vaddr & ~PAGE_MASK),
PROT_READ | PROT_EXEC,
MAP_FIXED | MAP_SHARED,
text_scnptr & PAGE_MASK);
status = (status == (text_vaddr & PAGE_MASK)) ? 0 : -ENOEXEC;
/*
* Map the data pages
*/
if (status >= 0 && data_size != 0) {
#ifdef COFF_DEBUG
printk (".data: vaddr = %d, size = %d, scnptr = %d\n",
data_vaddr,
data_size,
data_scnptr);
#endif
status = do_mmap (fp,
data_vaddr & PAGE_MASK,
data_size + (data_vaddr & ~PAGE_MASK),
PROT_READ | PROT_WRITE | PROT_EXEC,
MAP_FIXED | MAP_PRIVATE,
data_scnptr & PAGE_MASK);
status = (status == (data_vaddr & PAGE_MASK)) ? 0 : -ENOEXEC;
}
/*
* Construct the bss data for the process. The bss ranges from the
* end of the data (which may not be on a page boundary) to the end
* of the bss section. Allocate any necessary pages for the data.
*/
if (status >= 0 && bss_size != 0) {
#ifdef COFF_DEBUG
printk (".bss: vaddr = %d, size = %d\n",
bss_vaddr,
bss_size);
#endif
zeromap_page_range (PAGE_ALIGN (bss_vaddr),
PAGE_ALIGN (bss_size),
PAGE_COPY);
status = clear_memory (bss_vaddr, bss_size);
}
/*
* Load any shared library for the executable.
*/
if (status >= 0 && lib_ok && lib_count != 0) {
int nIndex;
COFF_SCNHDR *sect_ptr = sect_bufr;
/*
* Find the library sections. (There should be at least one. It was counted
* earlier.) This will eventually recurse to our code and load the shared
* library with our own procedures.
*/
for (nIndex = 0; nIndex < sections; ++nIndex) {
long int sect_flags = COFF_LONG (sect_ptr->s_flags);
if (sect_flags == COFF_STYP_LIB) {
status = preload_library (bprm, sect_ptr, fp);
if (status != 0)
break;
}
sect_ptr = (COFF_SCNHDR *) &((char *) sect_ptr) [COFF_SCNHSZ];
}
}
/*
* Generate any needed trap for this process. If an error occurred then
* generate a segmentation violation. If the process is being debugged
* then generate the load trap. (Note: If this is a library load then
* do not generate the trap here. Pass the error to the caller who
* will do it for the process in the outer lay of this procedure call.)
*/
if (lib_ok) {
if (status < 0)
send_sig (SIGSEGV, current, 0); /* Generate the error trap */
else {
if (current->flags & PF_PTRACED)
send_sig (SIGTRAP, current, 0);
}
status = 0; /* We are committed. It can't fail */
}
}
/*
* Do any cleanup processing
*/
if (fd >= 0)
sys_close (fd); /* Close unused code file */
if (sect_bufr != NULL)
kfree (sect_bufr); /* Release section list buffer */
/*
* Return the completion status.
*/
#ifdef COFF_DEBUG
printk ("binfmt_coff: result = %d\n", status);
#endif
return (status);
}
