2 * a.out loader for x86-64
4 * Copyright (C) 1991, 1992, 1996 Linus Torvalds
5 * Hacked together by Andi Kleen
8 #include <linux/module.h>
10 #include <linux/time.h>
11 #include <linux/kernel.h>
13 #include <linux/mman.h>
14 #include <linux/a.out.h>
15 #include <linux/errno.h>
16 #include <linux/signal.h>
17 #include <linux/string.h>
19 #include <linux/file.h>
20 #include <linux/stat.h>
21 #include <linux/fcntl.h>
22 #include <linux/ptrace.h>
23 #include <linux/user.h>
24 #include <linux/binfmts.h>
25 #include <linux/personality.h>
26 #include <linux/init.h>
27 #include <linux/jiffies.h>
29 #include <asm/uaccess.h>
30 #include <asm/pgalloc.h>
31 #include <asm/cacheflush.h>
32 #include <asm/user32.h>
36 #undef CORE_DUMP /* definitely broken */
38 static int load_aout_binary(struct linux_binprm *, struct pt_regs *regs);
39 static int load_aout_library(struct file *);
42 static int aout_core_dump(long signr, struct pt_regs *regs, struct file *file,
46 * fill in the user structure for a core dump..
48 static void dump_thread32(struct pt_regs *regs, struct user32 *dump)
52 /* changed the size calculations - should hopefully work better. lbt */
55 dump->start_stack = regs->sp & ~(PAGE_SIZE - 1);
56 dump->u_tsize = ((unsigned long) current->mm->end_code) >> PAGE_SHIFT;
57 dump->u_dsize = ((unsigned long)
58 (current->mm->brk + (PAGE_SIZE-1))) >> PAGE_SHIFT;
59 dump->u_dsize -= dump->u_tsize;
61 dump->u_debugreg[0] = current->thread.debugreg0;
62 dump->u_debugreg[1] = current->thread.debugreg1;
63 dump->u_debugreg[2] = current->thread.debugreg2;
64 dump->u_debugreg[3] = current->thread.debugreg3;
65 dump->u_debugreg[4] = 0;
66 dump->u_debugreg[5] = 0;
67 dump->u_debugreg[6] = current->thread.debugreg6;
68 dump->u_debugreg[7] = current->thread.debugreg7;
70 if (dump->start_stack < 0xc0000000) {
73 tmp = (unsigned long) (0xc0000000 - dump->start_stack);
74 dump->u_ssize = tmp >> PAGE_SHIFT;
77 dump->regs.bx = regs->bx;
78 dump->regs.cx = regs->cx;
79 dump->regs.dx = regs->dx;
80 dump->regs.si = regs->si;
81 dump->regs.di = regs->di;
82 dump->regs.bp = regs->bp;
83 dump->regs.ax = regs->ax;
84 dump->regs.ds = current->thread.ds;
85 dump->regs.es = current->thread.es;
90 dump->regs.orig_ax = regs->orig_ax;
91 dump->regs.ip = regs->ip;
92 dump->regs.cs = regs->cs;
93 dump->regs.flags = regs->flags;
94 dump->regs.sp = regs->sp;
95 dump->regs.ss = regs->ss;
100 dump->u_fpvalid = dump_fpu(regs, &dump->i387);
106 static struct linux_binfmt aout_format = {
107 .module = THIS_MODULE,
108 .load_binary = load_aout_binary,
109 .load_shlib = load_aout_library,
111 .core_dump = aout_core_dump,
113 .min_coredump = PAGE_SIZE
116 static void set_brk(unsigned long start, unsigned long end)
118 start = PAGE_ALIGN(start);
119 end = PAGE_ALIGN(end);
122 down_write(¤t->mm->mmap_sem);
123 do_brk(start, end - start);
124 up_write(¤t->mm->mmap_sem);
129 * These are the only things you should do on a core-file: use only these
130 * macros to write out all the necessary info.
133 #include <linux/coredump.h>
135 #define DUMP_WRITE(addr, nr) \
136 if (!dump_write(file, (void *)(addr), (nr))) \
139 #define DUMP_SEEK(offset) \
140 if (!dump_seek(file, offset)) \
143 #define START_DATA() (u.u_tsize << PAGE_SHIFT)
144 #define START_STACK(u) (u.start_stack)
147 * Routine writes a core dump image in the current directory.
148 * Currently only a stub-function.
150 * Note that setuid/setgid files won't make a core-dump if the uid/gid
151 * changed due to the set[u|g]id. It's enforced by the "current->mm->dumpable"
152 * field, which also makes sure the core-dumps won't be recursive if the
153 * dumping of the process results in another error..
156 static int aout_core_dump(long signr, struct pt_regs *regs, struct file *file,
161 unsigned long dump_start, dump_size;
167 current->flags |= PF_DUMPCORE;
168 strncpy(dump.u_comm, current->comm, sizeof(current->comm));
169 dump.u_ar0 = offsetof(struct user32, regs);
171 dump_thread32(regs, &dump);
174 * If the size of the dump file exceeds the rlimit, then see
175 * what would happen if we wrote the stack, but not the data
178 if ((dump.u_dsize + dump.u_ssize + 1) * PAGE_SIZE > limit)
181 /* Make sure we have enough room to write the stack and data areas. */
182 if ((dump.u_ssize + 1) * PAGE_SIZE > limit)
185 /* make sure we actually have a data and stack area to dump */
187 if (!access_ok(VERIFY_READ, (void *) (unsigned long)START_DATA(dump),
188 dump.u_dsize << PAGE_SHIFT))
190 if (!access_ok(VERIFY_READ, (void *) (unsigned long)START_STACK(dump),
191 dump.u_ssize << PAGE_SHIFT))
196 DUMP_WRITE(&dump, sizeof(dump));
197 /* Now dump all of the user data. Include malloced stuff as well */
198 DUMP_SEEK(PAGE_SIZE);
199 /* now we start writing out the user space info */
201 /* Dump the data area */
202 if (dump.u_dsize != 0) {
203 dump_start = START_DATA(dump);
204 dump_size = dump.u_dsize << PAGE_SHIFT;
205 DUMP_WRITE(dump_start, dump_size);
207 /* Now prepare to dump the stack area */
208 if (dump.u_ssize != 0) {
209 dump_start = START_STACK(dump);
210 dump_size = dump.u_ssize << PAGE_SHIFT;
211 DUMP_WRITE(dump_start, dump_size);
220 * create_aout_tables() parses the env- and arg-strings in new user
221 * memory and creates the pointer tables from them, and puts their
222 * addresses on the "stack", returning the new stack pointer value.
224 static u32 __user *create_aout_tables(char __user *p, struct linux_binprm *bprm)
226 u32 __user *argv, *envp, *sp;
227 int argc = bprm->argc, envc = bprm->envc;
229 sp = (u32 __user *) ((-(unsigned long)sizeof(u32)) & (unsigned long) p);
234 put_user((unsigned long) envp, --sp);
235 put_user((unsigned long) argv, --sp);
236 put_user(argc, --sp);
237 current->mm->arg_start = (unsigned long) p;
241 put_user((u32)(unsigned long)p, argv++);
247 current->mm->arg_end = current->mm->env_start = (unsigned long) p;
251 put_user((u32)(unsigned long)p, envp++);
257 current->mm->env_end = (unsigned long) p;
262 * These are the functions used to load a.out style executables and shared
263 * libraries. There is no binary dependent code anywhere else.
265 static int load_aout_binary(struct linux_binprm *bprm, struct pt_regs *regs)
267 unsigned long error, fd_offset, rlim;
271 ex = *((struct exec *) bprm->buf); /* exec-header */
272 if ((N_MAGIC(ex) != ZMAGIC && N_MAGIC(ex) != OMAGIC &&
273 N_MAGIC(ex) != QMAGIC && N_MAGIC(ex) != NMAGIC) ||
274 N_TRSIZE(ex) || N_DRSIZE(ex) ||
275 i_size_read(bprm->file->f_path.dentry->d_inode) <
276 ex.a_text+ex.a_data+N_SYMSIZE(ex)+N_TXTOFF(ex)) {
280 fd_offset = N_TXTOFF(ex);
282 /* Check initial limits. This avoids letting people circumvent
283 * size limits imposed on them by creating programs with large
284 * arrays in the data or bss.
286 rlim = rlimit(RLIMIT_DATA);
287 if (rlim >= RLIM_INFINITY)
289 if (ex.a_data + ex.a_bss > rlim)
292 /* Flush all traces of the currently running executable */
293 retval = flush_old_exec(bprm);
297 /* OK, This is the point of no return */
298 set_personality(PER_LINUX);
299 set_thread_flag(TIF_IA32);
300 current->mm->context.ia32_compat = 1;
302 setup_new_exec(bprm);
304 regs->cs = __USER32_CS;
305 regs->r8 = regs->r9 = regs->r10 = regs->r11 = regs->r12 =
306 regs->r13 = regs->r14 = regs->r15 = 0;
308 current->mm->end_code = ex.a_text +
309 (current->mm->start_code = N_TXTADDR(ex));
310 current->mm->end_data = ex.a_data +
311 (current->mm->start_data = N_DATADDR(ex));
312 current->mm->brk = ex.a_bss +
313 (current->mm->start_brk = N_BSSADDR(ex));
314 current->mm->free_area_cache = TASK_UNMAPPED_BASE;
315 current->mm->cached_hole_size = 0;
317 retval = setup_arg_pages(bprm, IA32_STACK_TOP, EXSTACK_DEFAULT);
319 /* Someone check-me: is this error path enough? */
320 send_sig(SIGKILL, current, 0);
324 install_exec_creds(bprm);
326 if (N_MAGIC(ex) == OMAGIC) {
327 unsigned long text_addr, map_size;
330 text_addr = N_TXTADDR(ex);
333 map_size = ex.a_text+ex.a_data;
335 down_write(¤t->mm->mmap_sem);
336 error = do_brk(text_addr & PAGE_MASK, map_size);
337 up_write(¤t->mm->mmap_sem);
339 if (error != (text_addr & PAGE_MASK)) {
340 send_sig(SIGKILL, current, 0);
344 error = bprm->file->f_op->read(bprm->file,
345 (char __user *)text_addr,
346 ex.a_text+ex.a_data, &pos);
347 if ((signed long)error < 0) {
348 send_sig(SIGKILL, current, 0);
352 flush_icache_range(text_addr, text_addr+ex.a_text+ex.a_data);
355 static unsigned long error_time, error_time2;
356 if ((ex.a_text & 0xfff || ex.a_data & 0xfff) &&
357 (N_MAGIC(ex) != NMAGIC) &&
358 time_after(jiffies, error_time2 + 5*HZ)) {
359 printk(KERN_NOTICE "executable not page aligned\n");
360 error_time2 = jiffies;
363 if ((fd_offset & ~PAGE_MASK) != 0 &&
364 time_after(jiffies, error_time + 5*HZ)) {
366 "fd_offset is not page aligned. Please convert "
368 bprm->file->f_path.dentry->d_name.name);
369 error_time = jiffies;
373 if (!bprm->file->f_op->mmap || (fd_offset & ~PAGE_MASK) != 0) {
374 loff_t pos = fd_offset;
376 down_write(¤t->mm->mmap_sem);
377 do_brk(N_TXTADDR(ex), ex.a_text+ex.a_data);
378 up_write(¤t->mm->mmap_sem);
379 bprm->file->f_op->read(bprm->file,
380 (char __user *)N_TXTADDR(ex),
381 ex.a_text+ex.a_data, &pos);
382 flush_icache_range((unsigned long) N_TXTADDR(ex),
383 (unsigned long) N_TXTADDR(ex) +
384 ex.a_text+ex.a_data);
388 down_write(¤t->mm->mmap_sem);
389 error = do_mmap(bprm->file, N_TXTADDR(ex), ex.a_text,
390 PROT_READ | PROT_EXEC,
391 MAP_FIXED | MAP_PRIVATE | MAP_DENYWRITE |
392 MAP_EXECUTABLE | MAP_32BIT,
394 up_write(¤t->mm->mmap_sem);
396 if (error != N_TXTADDR(ex)) {
397 send_sig(SIGKILL, current, 0);
401 down_write(¤t->mm->mmap_sem);
402 error = do_mmap(bprm->file, N_DATADDR(ex), ex.a_data,
403 PROT_READ | PROT_WRITE | PROT_EXEC,
404 MAP_FIXED | MAP_PRIVATE | MAP_DENYWRITE |
405 MAP_EXECUTABLE | MAP_32BIT,
406 fd_offset + ex.a_text);
407 up_write(¤t->mm->mmap_sem);
408 if (error != N_DATADDR(ex)) {
409 send_sig(SIGKILL, current, 0);
414 set_binfmt(&aout_format);
416 set_brk(current->mm->start_brk, current->mm->brk);
418 current->mm->start_stack =
419 (unsigned long)create_aout_tables((char __user *)bprm->p, bprm);
422 loadsegment(ds, __USER32_DS);
423 loadsegment(es, __USER32_DS);
425 (regs)->ip = ex.a_entry;
426 (regs)->sp = current->mm->start_stack;
427 (regs)->flags = 0x200;
428 (regs)->cs = __USER32_CS;
429 (regs)->ss = __USER32_DS;
430 regs->r8 = regs->r9 = regs->r10 = regs->r11 =
431 regs->r12 = regs->r13 = regs->r14 = regs->r15 = 0;
436 static int load_aout_library(struct file *file)
439 unsigned long bss, start_addr, len, error;
443 inode = file->f_path.dentry->d_inode;
446 error = kernel_read(file, 0, (char *) &ex, sizeof(ex));
447 if (error != sizeof(ex))
450 /* We come in here for the regular a.out style of shared libraries */
451 if ((N_MAGIC(ex) != ZMAGIC && N_MAGIC(ex) != QMAGIC) || N_TRSIZE(ex) ||
452 N_DRSIZE(ex) || ((ex.a_entry & 0xfff) && N_MAGIC(ex) == ZMAGIC) ||
454 ex.a_text+ex.a_data+N_SYMSIZE(ex)+N_TXTOFF(ex)) {
461 /* For QMAGIC, the starting address is 0x20 into the page. We mask
462 this off to get the starting address for the page */
464 start_addr = ex.a_entry & 0xfffff000;
466 if ((N_TXTOFF(ex) & ~PAGE_MASK) != 0) {
467 loff_t pos = N_TXTOFF(ex);
470 static unsigned long error_time;
471 if (time_after(jiffies, error_time + 5*HZ)) {
473 "N_TXTOFF is not page aligned. Please convert "
475 file->f_path.dentry->d_name.name);
476 error_time = jiffies;
479 down_write(¤t->mm->mmap_sem);
480 do_brk(start_addr, ex.a_text + ex.a_data + ex.a_bss);
481 up_write(¤t->mm->mmap_sem);
483 file->f_op->read(file, (char __user *)start_addr,
484 ex.a_text + ex.a_data, &pos);
485 flush_icache_range((unsigned long) start_addr,
486 (unsigned long) start_addr + ex.a_text +
492 /* Now use mmap to map the library into memory. */
493 down_write(¤t->mm->mmap_sem);
494 error = do_mmap(file, start_addr, ex.a_text + ex.a_data,
495 PROT_READ | PROT_WRITE | PROT_EXEC,
496 MAP_FIXED | MAP_PRIVATE | MAP_DENYWRITE | MAP_32BIT,
498 up_write(¤t->mm->mmap_sem);
500 if (error != start_addr)
503 len = PAGE_ALIGN(ex.a_text + ex.a_data);
504 bss = ex.a_text + ex.a_data + ex.a_bss;
506 down_write(¤t->mm->mmap_sem);
507 error = do_brk(start_addr + len, bss - len);
508 up_write(¤t->mm->mmap_sem);
510 if (error != start_addr + len)
518 static int __init init_aout_binfmt(void)
520 register_binfmt(&aout_format);
524 static void __exit exit_aout_binfmt(void)
526 unregister_binfmt(&aout_format);
529 module_init(init_aout_binfmt);
530 module_exit(exit_aout_binfmt);
531 MODULE_LICENSE("GPL");