static int mmap_zero(struct inode * inode, struct file * file,
unsigned long addr, size_t len, int prot, unsigned long off)
{
struct vm_area_struct *mpnt;
if (prot & PAGE_RW)
return -EINVAL;
if (zeromap_page_range(addr, len, prot))
return -EAGAIN;
/*
* try to create a dummy vmm-structure so that the
* rest of the kernel knows we are here
*/
mpnt = (struct vm_area_struct *)kmalloc(sizeof(*mpnt), GFP_KERNEL);
if (!mpnt)
return 0;
mpnt->vm_task = current;
mpnt->vm_start = addr;
mpnt->vm_end = addr + len;
mpnt->vm_page_prot = prot;
mpnt->vm_share = NULL;
mpnt->vm_inode = NULL;
mpnt->vm_offset = off;
mpnt->vm_ops = NULL;
insert_vm_struct(current, mpnt);
merge_segments(current->mmap, ignoff_mergep, inode);
return 0;
}
static int mmap_zero(struct file * file, struct vm_area_struct * vma)
{
if (vma->vm_flags & VM_SHARED)
return shmem_zero_setup(vma);
if (zeromap_page_range(vma->vm_start, vma->vm_end - vma->vm_start, vma->vm_page_prot))
return -EAGAIN;
return 0;
}
/*
* For fun, we are using the MMU for this.
*/
static inline size_t read_zero_pagealigned(char * buf, size_t size)
{
struct mm_struct *mm;
struct vm_area_struct * vma;
unsigned long addr=(unsigned long)buf;
mm = current->mm;
/* Oops, this was forgotten before. -ben */
down(&mm->mmap_sem);
/* For private mappings, just map in zero pages. */
for (vma = find_vma(mm, addr); vma; vma = vma->vm_next) {
unsigned long count;
if (vma->vm_start > addr || (vma->vm_flags & VM_WRITE) == 0)
goto out_up;
if (vma->vm_flags & VM_SHARED)
break;
count = vma->vm_end - addr;
if (count > size)
count = size;
flush_cache_range(mm, addr, addr + count);
zap_page_range(mm, addr, count);
zeromap_page_range(addr, count, PAGE_COPY);
flush_tlb_range(mm, addr, addr + count);
size -= count;
buf += count;
addr += count;
if (size == 0)
goto out_up;
}
up(&mm->mmap_sem);
/* The shared case is hard. Let's do the conventional zeroing. */
do {
unsigned long unwritten = clear_user(buf, PAGE_SIZE);
if (unwritten)
return size + unwritten - PAGE_SIZE;
if (current->need_resched)
schedule();
buf += PAGE_SIZE;
size -= PAGE_SIZE;
} while (size);
return size;
out_up:
up(&mm->mmap_sem);
return size;
}
static int anon_map(struct inode *ino, struct file *file, struct vm_area_struct *vma)
{
if (zeromap_page_range(vma->vm_start, vma->vm_end - vma->vm_start, vma->vm_page_prot))
return -ENOMEM;
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);
}