/*
* linux/fs/binfmt_aout.c
*
* Copyright (C) 1991, 1992, 1996 Linus Torvalds
*
* Hacked a bit by DaveM to make it work with 32-bit SunOS
* binaries on the sparc64 port.
*/
#include <linux/module.h>
#include <linux/sched.h>
#include <linux/kernel.h>
#include <linux/mm.h>
#include <linux/mman.h>
#include <linux/a.out.h>
#include <linux/errno.h>
#include <linux/signal.h>
#include <linux/string.h>
#include <linux/fs.h>
#include <linux/file.h>
#include <linux/stat.h>
#include <linux/fcntl.h>
#include <linux/ptrace.h>
#include <linux/user.h>
#include <linux/slab.h>
#include <linux/binfmts.h>
#include <linux/personality.h>
#include <linux/init.h>
#include <asm/system.h>
#include <asm/uaccess.h>
#include <asm/pgalloc.h>
#include <asm/mmu_context.h>
static int load_aout32_binary(struct linux_binprm *, struct pt_regs * regs);
static int load_aout32_library(struct file*);
static int aout32_core_dump(long signr, struct pt_regs *regs, struct file *file, unsigned long limit);
static struct linux_binfmt aout32_format = {
.module = THIS_MODULE,
.load_binary = load_aout32_binary,
.load_shlib = load_aout32_library,
.core_dump = aout32_core_dump,
.min_coredump = PAGE_SIZE,
};
static void set_brk(unsigned long start, unsigned long end)
{
start = PAGE_ALIGN(start);
end = PAGE_ALIGN(end);
if (end <= start)
return;
down_write(¤t->mm->mmap_sem);
do_brk(start, end - start);
up_write(¤t->mm->mmap_sem);
}
/*
* These are the only things you should do on a core-file: use only these
* macros to write out all the necessary info.
*/
static int dump_write(struct file *file, const void *addr, int nr)
{
return file->f_op->write(file, addr, nr, &file->f_pos) == nr;
}
#define DUMP_WRITE(addr, nr) \
if (!dump_write(file, (void *)(addr), (nr))) \
goto end_coredump;
#define DUMP_SEEK(offset) \
if (file->f_op->llseek) { \
if (file->f_op->llseek(file,(offset),0) != (offset)) \
goto end_coredump; \
} else file->f_pos = (offset)
/*
* Routine writes a core dump image in the current directory.
* Currently only a stub-function.
*
* Note that setuid/setgid files won't make a core-dump if the uid/gid
* changed due to the set[u|g]id. It's enforced by the "current->mm->dumpable"
* field, which also makes sure the core-dumps won't be recursive if the
* dumping of the process results in another error..
*/
static int aout32_core_dump(long signr, struct pt_regs *regs, struct file *file, unsigned long limit)
{
mm_segment_t fs;
int has_dumped = 0;
unsigned long dump_start, dump_size;
struct user dump;
# define START_DATA(u) (u.u_tsize)
# define START_STACK(u) ((regs->u_regs[UREG_FP]) & ~(PAGE_SIZE - 1))
fs = get_fs();
set_fs(KERNEL_DS);
has_dumped = 1;
current->flags |= PF_DUMPCORE;
strncpy(dump.u_comm, current->comm, sizeof(dump.u_comm));
dump.signal = signr;
dump_thread(regs, &dump);
/* If the size of the dump file exceeds the rlimit, then see what would happen
if we wrote the stack, but not the data area. */
if (dump.u_dsize + dump.u_ssize > limit)
dump.u_dsize = 0;
/* Make sure we have enough room to write the stack and data areas. */
if (dump.u_ssize > limit)
dump.u_ssize = 0;
/* make sure we actually have a data and stack area to dump */
set_fs(USER_DS);
if (!access_ok(VERIFY_READ, (void __user *) START_DATA(dump), dump.u_dsize))
dump.u_dsize = 0;
if (!access_ok(VERIFY_READ, (void __user *) START_STACK(dump), dump.u_ssize))
dump.u_ssize = 0;
set_fs(KERNEL_DS);
/* struct user */
DUMP_WRITE(&dump,sizeof(dump));
/* now we start writing out the user space info */
set_fs(USER_DS);
/* Dump the data area */
if (dump.u_dsize != 0) {
dump_start = START_DATA(dump);
dump_size = dump.u_dsize;
DUMP_WRITE(dump_start,dump_size);
}
/* Now prepare to dump the stack area */
if (dump.u_ssize != 0) {
dump_start = START_STACK(dump);
dump_size = dump.u_ssize;
DUMP_WRITE(dump_start,dump_size);
}
/* Finally dump the task struct. Not be used by gdb, but could be useful */
set_fs(KERNEL_DS);
DUMP_WRITE(current,sizeof(*current));
end_coredump:
set_fs(fs);
return has_dumped;
}
/*
* create_aout32_tables() parses the env- and arg-strings in new user
* memory and creates the pointer tables from them, and puts their
* addresses on the "stack", returning the new stack pointer value.
*/
static u32 __user *create_aout32_tables(char __user *p, struct linux_binprm *bprm)
{
u32 __user *argv;
u32 __user *envp;
u32 __user *sp;
int argc = bprm->argc;
int envc = bprm->envc;
sp = (u32 __user *)((-(unsigned long)sizeof(char *))&(unsigned long)p);
/* This imposes the proper stack alignment for a new process. */
sp = (u32 __user *) (((unsigned long) sp) & ~7);
if ((envc+argc+3)&1)
--sp;
sp -= envc+1;
envp = sp;
sp -= argc+1;
argv = sp;
put_user(argc,--sp);
current->mm->arg_start = (unsigned long) p;
while (argc-->0) {
char c;
put_user(((u32)(unsigned long)(p)),argv++);
do {
get_user(c,p++);
} while (c);
}
put_user(0,argv);
current->mm->arg_end = current->mm->env_start = (unsigned long) p;
while (envc-->0) {
char c;
put_user(((u32)(unsigned long)(p)),envp++);
do {
get_user(c,p++);
} while (c);
}
put_user(0,envp);
current->mm->env_end = (unsigned long) p;
return sp;
}
/*
* These are the functions used to load a.out style executables and shared
* libraries. There is no binary dependent code anywhere else.
*/
static int load_aout32_binary(struct linux_binprm * bprm, struct pt_regs * regs)
{
struct exec ex;
unsigned long error;
unsigned long fd_offset;
unsigned long rlim;
unsigned long orig_thr_flags;
int retval;
ex = *((struct exec *) bprm->buf); /* exec-header */
if ((N_MAGIC(ex) != ZMAGIC && N_MAGIC(ex) != OMAGIC &&
N_MAGIC(ex) != QMAGIC && N_MAGIC(ex) != NMAGIC) ||
N_TRSIZE(ex) || N_DRSIZE(ex) ||
bprm->file->f_path.dentry->d_inode->i_size < ex.a_text+ex.a_data+N_SYMSIZE(ex)+N_TXTOFF(ex)) {
return -ENOEXEC;
}
fd_offset = N_TXTOFF(ex);
/* Check initial limits. This avoids letting people circumvent
* size limits imposed on them by creating programs with large
* arrays in the data or bss.
*/
rlim = current->signal->rlim[RLIMIT_DATA].rlim_cur;
if (rlim >= RLIM_INFINITY)
rlim = ~0;
if (ex.a_data + ex.a_bss > rlim)
return -ENOMEM;
/* Flush all traces of the currently running executable */
retval = flush_old_exec(bprm);
if (retval)
return retval;
/* OK, This is the point of no return */
set_personality(PER_SUNOS);
current->mm->end_code = ex.a_text +
(current->mm->start_code = N_TXTADDR(ex));
current->mm->end_data = ex.a_data +
(current->mm->start_data = N_DATADDR(ex));
current->mm->brk = ex.a_bss +
(current->mm->start_brk = N_BSSADDR(ex));
current->mm->free_area_cache = current->mm->mmap_base;
current->mm->cached_hole_size = 0;
current->mm->mmap = NULL;
compute_creds(bprm);
current->flags &= ~PF_FORKNOEXEC;
if (N_MAGIC(ex) == NMAGIC) {
loff_t pos = fd_offset;
/* Fuck me plenty... */
down_write(¤t->mm->mmap_sem);
error = do_brk(N_TXTADDR(ex), ex.a_text);
up_write(¤t->mm->mmap_sem);
bprm->file->f_op->read(bprm->file, (char __user *)N_TXTADDR(ex),
ex.a_text, &pos);
down_write(¤t->mm->mmap_sem);
error = do_brk(N_DATADDR(ex), ex.a_data);
up_write(¤t->mm->mmap_sem);
bprm->file->f_op->read(bprm->file, (char __user *)N_DATADDR(ex),
ex.a_data, &pos);
goto beyond_if;
}
if (N_MAGIC(ex) == OMAGIC) {
loff_t pos = fd_offset;
down_write(¤t->mm->mmap_sem);
do_brk(N_TXTADDR(ex) & PAGE_MASK,
ex.a_text+ex.a_data + PAGE_SIZE - 1);
up_write(¤t->mm->mmap_sem);
bprm->file->f_op->read(bprm->file, (char __user *)N_TXTADDR(ex),
ex.a_text+ex.a_data, &pos);
} else {
static unsigned long error_time;
if ((ex.a_text & 0xfff || ex.a_data & 0xfff) &&
(N_MAGIC(ex) != NMAGIC) && (jiffies-error_time) > 5*HZ)
{
printk(KERN_NOTICE "executable not page aligned\n");
error_time = jiffies;
}
if (!bprm->file->f_op->mmap) {
loff_t pos = fd_offset;
down_write(¤t->mm->mmap_sem);
do_brk(0, ex.a_text+ex.a_data);
up_write(¤t->mm->mmap_sem);
bprm->file->f_op->read(bprm->file,
(char __user *)N_TXTADDR(ex),
ex.a_text+ex.a_data, &pos);
goto beyond_if;
}
down_write(¤t->mm->mmap_sem);
error = do_mmap(bprm->file, N_TXTADDR(ex), ex.a_text,
PROT_READ | PROT_EXEC,
MAP_FIXED | MAP_PRIVATE | MAP_DENYWRITE | MAP_EXECUTABLE,
fd_offset);
up_write(¤t->mm->mmap_sem);
if (error != N_TXTADDR(ex)) {
send_sig(SIGKILL, current, 0);
return error;
}
down_write(¤t->mm->mmap_sem);
error = do_mmap(bprm->file, N_DATADDR(ex), ex.a_data,
PROT_READ | PROT_WRITE | PROT_EXEC,
MAP_FIXED | MAP_PRIVATE | MAP_DENYWRITE | MAP_EXECUTABLE,
fd_offset + ex.a_text);
up_write(¤t->mm->mmap_sem);
if (error != N_DATADDR(ex)) {
send_sig(SIGKILL, current, 0);
return error;
}
}
beyond_if:
set_binfmt(&aout32_format);
set_brk(current->mm->start_brk, current->mm->brk);
/* Make sure STACK_TOP returns the right thing. */
orig_thr_flags = current_thread_info()->flags;
current_thread_info()->flags |= _TIF_32BIT;
retval = setup_arg_pages(bprm, STACK_TOP, EXSTACK_DEFAULT);
if (retval < 0) {
current_thread_info()->flags = orig_thr_flags;
/* Someone check-me: is this error path enough? */
send_sig(SIGKILL, current, 0);
return retval;
}
current->mm->start_stack =
(unsigned long) create_aout32_tables((char __user *)bprm->p, bprm);
tsb_context_switch(current->mm);
start_thread32(regs, ex.a_entry, current->mm->start_stack);
if (current->ptrace & PT_PTRACED)
send_sig(SIGTRAP, current, 0);
return 0;
}
/* N.B. Move to .h file and use code in fs/binfmt_aout.c? */
static int load_aout32_library(struct file *file)
{
struct inode * inode;
unsigned long bss, start_addr, len;
unsigned long error;
int retval;
struct exec ex;
inode = file->f_path.dentry->d_inode;
retval = -ENOEXEC;
error = kernel_read(file, 0, (char *) &ex, sizeof(ex));
if (error != sizeof(ex))
goto out;
/* We come in here for the regular a.out style of shared libraries */
if ((N_MAGIC(ex) != ZMAGIC && N_MAGIC(ex) != QMAGIC) || N_TRSIZE(ex) ||
N_DRSIZE(ex) || ((ex.a_entry & 0xfff) && N_MAGIC(ex) == ZMAGIC) ||
inode->i_size < ex.a_text+ex.a_data+N_SYMSIZE(ex)+N_TXTOFF(ex)) {
goto out;
}
if (N_MAGIC(ex) == ZMAGIC && N_TXTOFF(ex) &&
(N_TXTOFF(ex) < inode->i_sb->s_blocksize)) {
printk("N_TXTOFF < BLOCK_SIZE. Please convert library\n");
goto out;
}
if (N_FLAGS(ex))
goto out;
/* For QMAGIC, the starting address is 0x20 into the page. We mask
this off to get the starting address for the page */
start_addr = ex.a_entry & 0xfffff000;
/* Now use mmap to map the library into memory. */
down_write(¤t->mm->mmap_sem);
error = do_mmap(file, start_addr, ex.a_text + ex.a_data,
PROT_READ | PROT_WRITE | PROT_EXEC,
MAP_FIXED | MAP_PRIVATE | MAP_DENYWRITE,
N_TXTOFF(ex));
up_write(¤t->mm->mmap_sem);
retval = error;
if (error != start_addr)
goto out;
len = PAGE_ALIGN(ex.a_text + ex.a_data);
bss = ex.a_text + ex.a_data + ex.a_bss;
if (bss > len) {
down_write(¤t->mm->mmap_sem);
error = do_brk(start_addr + len, bss - len);
up_write(¤t->mm->mmap_sem);
retval = error;
if (error != start_addr + len)
goto out;
}
retval = 0;
out:
return retval;
}
static int __init init_aout32_binfmt(void)
{
return register_binfmt(&aout32_format);
}
static void __exit exit_aout32_binfmt(void)
{
unregister_binfmt(&aout32_format);
}
module_init(init_aout32_binfmt);
module_exit(exit_aout32_binfmt);
