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DEFINITIONS
This source file includes following definitions.
- dump_thread32
- set_brk
- dump_write
- aout_core_dump
- create_aout_tables
- load_aout_binary
- load_aout_library
- init_aout_binfmt
- exit_aout_binfmt
/*
* a.out loader for x86-64
*
* Copyright (C) 1991, 1992, 1996 Linus Torvalds
* Hacked together by Andi Kleen
*/
#include <linux/module.h>
#include <linux/time.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 <linux/jiffies.h>
#include <asm/system.h>
#include <asm/uaccess.h>
#include <asm/pgalloc.h>
#include <asm/cacheflush.h>
#include <asm/user32.h>
#include <asm/ia32.h>
#undef WARN_OLD
#undef CORE_DUMP /* probably broken */
static int load_aout_binary(struct linux_binprm *, struct pt_regs *regs);
static int load_aout_library(struct file *);
#ifdef CORE_DUMP
static int aout_core_dump(long signr, struct pt_regs *regs, struct file *file,
unsigned long limit);
/*
* fill in the user structure for a core dump..
*/
static void dump_thread32(struct pt_regs *regs, struct user32 *dump)
{
u32 fs, gs;
/* changed the size calculations - should hopefully work better. lbt */
dump->magic = CMAGIC;
dump->start_code = 0;
dump->start_stack = regs->sp & ~(PAGE_SIZE - 1);
dump->u_tsize = ((unsigned long) current->mm->end_code) >> PAGE_SHIFT;
dump->u_dsize = ((unsigned long)
(current->mm->brk + (PAGE_SIZE-1))) >> PAGE_SHIFT;
dump->u_dsize -= dump->u_tsize;
dump->u_ssize = 0;
dump->u_debugreg[0] = current->thread.debugreg0;
dump->u_debugreg[1] = current->thread.debugreg1;
dump->u_debugreg[2] = current->thread.debugreg2;
dump->u_debugreg[3] = current->thread.debugreg3;
dump->u_debugreg[4] = 0;
dump->u_debugreg[5] = 0;
dump->u_debugreg[6] = current->thread.debugreg6;
dump->u_debugreg[7] = current->thread.debugreg7;
if (dump->start_stack < 0xc0000000) {
unsigned long tmp;
tmp = (unsigned long) (0xc0000000 - dump->start_stack);
dump->u_ssize = tmp >> PAGE_SHIFT;
}
dump->regs.bx = regs->bx;
dump->regs.cx = regs->cx;
dump->regs.dx = regs->dx;
dump->regs.si = regs->si;
dump->regs.di = regs->di;
dump->regs.bp = regs->bp;
dump->regs.ax = regs->ax;
dump->regs.ds = current->thread.ds;
dump->regs.es = current->thread.es;
savesegment(fs, fs);
dump->regs.fs = fs;
savesegment(gs, gs);
dump->regs.gs = gs;
dump->regs.orig_ax = regs->orig_ax;
dump->regs.ip = regs->ip;
dump->regs.cs = regs->cs;
dump->regs.flags = regs->flags;
dump->regs.sp = regs->sp;
dump->regs.ss = regs->ss;
#if 1 /* FIXME */
dump->u_fpvalid = 0;
#else
dump->u_fpvalid = dump_fpu(regs, &dump->i387);
#endif
}
#endif
static struct linux_binfmt aout_format = {
.module = THIS_MODULE,
.load_binary = load_aout_binary,
.load_shlib = load_aout_library,
#ifdef CORE_DUMP
.core_dump = aout_core_dump,
#endif
.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);
}
#ifdef CORE_DUMP
/*
* 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)
#define START_DATA() (u.u_tsize << PAGE_SHIFT)
#define START_STACK(u) (u.start_stack)
/*
* 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 aout_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 user32 dump;
fs = get_fs();
set_fs(KERNEL_DS);
has_dumped = 1;
current->flags |= PF_DUMPCORE;
strncpy(dump.u_comm, current->comm, sizeof(current->comm));
dump.u_ar0 = offsetof(struct user32, regs);
dump.signal = signr;
dump_thread32(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 + 1) * PAGE_SIZE > limit)
dump.u_dsize = 0;
/* Make sure we have enough room to write the stack and data areas. */
if ((dump.u_ssize + 1) * PAGE_SIZE > 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 *) (unsigned long)START_DATA(dump),
dump.u_dsize << PAGE_SHIFT))
dump.u_dsize = 0;
if (!access_ok(VERIFY_READ, (void *) (unsigned long)START_STACK(dump),
dump.u_ssize << PAGE_SHIFT))
dump.u_ssize = 0;
set_fs(KERNEL_DS);
/* struct user */
DUMP_WRITE(&dump, sizeof(dump));
/* Now dump all of the user data. Include malloced stuff as well */
DUMP_SEEK(PAGE_SIZE);
/* 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 << PAGE_SHIFT;
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 << PAGE_SHIFT;
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;
}
#endif
/*
* create_aout_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_aout_tables(char __user *p, struct linux_binprm *bprm)
{
u32 __user *argv, *envp, *sp;
int argc = bprm->argc, envc = bprm->envc;
sp = (u32 __user *) ((-(unsigned long)sizeof(u32)) & (unsigned long) p);
sp -= envc+1;
envp = sp;
sp -= argc+1;
argv = sp;
put_user((unsigned long) envp, --sp);
put_user((unsigned long) 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_aout_binary(struct linux_binprm *bprm, struct pt_regs *regs)
{
unsigned long error, fd_offset, rlim;
struct exec ex;
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) ||
i_size_read(bprm->file->f_path.dentry->d_inode) <
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;
regs->cs = __USER32_CS;
regs->r8 = regs->r9 = regs->r10 = regs->r11 = regs->r12 =
regs->r13 = regs->r14 = regs->r15 = 0;
/* OK, This is the point of no return */
set_personality(PER_LINUX);
set_thread_flag(TIF_IA32);
clear_thread_flag(TIF_ABI_PENDING);
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 = TASK_UNMAPPED_BASE;
current->mm->cached_hole_size = 0;
current->mm->mmap = NULL;
compute_creds(bprm);
current->flags &= ~PF_FORKNOEXEC;
if (N_MAGIC(ex) == OMAGIC) {
unsigned long text_addr, map_size;
loff_t pos;
text_addr = N_TXTADDR(ex);
pos = 32;
map_size = ex.a_text+ex.a_data;
down_write(¤t->mm->mmap_sem);
error = do_brk(text_addr & PAGE_MASK, map_size);
up_write(¤t->mm->mmap_sem);
if (error != (text_addr & PAGE_MASK)) {
send_sig(SIGKILL, current, 0);
return error;
}
error = bprm->file->f_op->read(bprm->file,
(char __user *)text_addr,
ex.a_text+ex.a_data, &pos);
if ((signed long)error < 0) {
send_sig(SIGKILL, current, 0);
return error;
}
flush_icache_range(text_addr, text_addr+ex.a_text+ex.a_data);
} else {
#ifdef WARN_OLD
static unsigned long error_time, error_time2;
if ((ex.a_text & 0xfff || ex.a_data & 0xfff) &&
(N_MAGIC(ex) != NMAGIC) &&
time_after(jiffies, error_time2 + 5*HZ)) {
printk(KERN_NOTICE "executable not page aligned\n");
error_time2 = jiffies;
}
if ((fd_offset & ~PAGE_MASK) != 0 &&
time_after(jiffies, error_time + 5*HZ)) {
printk(KERN_WARNING
"fd_offset is not page aligned. Please convert "
"program: %s\n",
bprm->file->f_path.dentry->d_name.name);
error_time = jiffies;
}
#endif
if (!bprm->file->f_op->mmap || (fd_offset & ~PAGE_MASK) != 0) {
loff_t pos = fd_offset;
down_write(¤t->mm->mmap_sem);
do_brk(N_TXTADDR(ex), 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);
flush_icache_range((unsigned long) N_TXTADDR(ex),
(unsigned long) N_TXTADDR(ex) +
ex.a_text+ex.a_data);
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 | MAP_32BIT,
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 | MAP_32BIT,
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(&aout_format);
set_brk(current->mm->start_brk, current->mm->brk);
retval = setup_arg_pages(bprm, IA32_STACK_TOP, EXSTACK_DEFAULT);
if (retval < 0) {
/* Someone check-me: is this error path enough? */
send_sig(SIGKILL, current, 0);
return retval;
}
current->mm->start_stack =
(unsigned long)create_aout_tables((char __user *)bprm->p, bprm);
/* start thread */
loadsegment(fs, 0);
loadsegment(ds, __USER32_DS);
loadsegment(es, __USER32_DS);
load_gs_index(0);
(regs)->ip = ex.a_entry;
(regs)->sp = current->mm->start_stack;
(regs)->flags = 0x200;
(regs)->cs = __USER32_CS;
(regs)->ss = __USER32_DS;
regs->r8 = regs->r9 = regs->r10 = regs->r11 =
regs->r12 = regs->r13 = regs->r14 = regs->r15 = 0;
set_fs(USER_DS);
return 0;
}
static int load_aout_library(struct file *file)
{
struct inode *inode;
unsigned long bss, start_addr, len, 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) ||
i_size_read(inode) <
ex.a_text+ex.a_data+N_SYMSIZE(ex)+N_TXTOFF(ex)) {
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;
if ((N_TXTOFF(ex) & ~PAGE_MASK) != 0) {
loff_t pos = N_TXTOFF(ex);
#ifdef WARN_OLD
static unsigned long error_time;
if (time_after(jiffies, error_time + 5*HZ)) {
printk(KERN_WARNING
"N_TXTOFF is not page aligned. Please convert "
"library: %s\n",
file->f_path.dentry->d_name.name);
error_time = jiffies;
}
#endif
down_write(¤t->mm->mmap_sem);
do_brk(start_addr, ex.a_text + ex.a_data + ex.a_bss);
up_write(¤t->mm->mmap_sem);
file->f_op->read(file, (char __user *)start_addr,
ex.a_text + ex.a_data, &pos);
flush_icache_range((unsigned long) start_addr,
(unsigned long) start_addr + ex.a_text +
ex.a_data);
retval = 0;
goto out;
}
/* 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 | MAP_32BIT,
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_aout_binfmt(void)
{
return register_binfmt(&aout_format);
}
static void __exit exit_aout_binfmt(void)
{
unregister_binfmt(&aout_format);
}
module_init(init_aout_binfmt);
module_exit(exit_aout_binfmt);
MODULE_LICENSE("GPL");