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/arch/x86_64/ia32/ia32_aout.c

https://bitbucket.org/evzijst/gittest
C | 529 lines | 407 code | 68 blank | 54 comment | 71 complexity | 1bfa252d5fbce4f50d15b5f8761352fe MD5 | raw file
  1/*
  2 *  a.out loader for x86-64
  3 *
  4 *  Copyright (C) 1991, 1992, 1996  Linus Torvalds
  5 *  Hacked together by Andi Kleen
  6 */
  7
  8#include <linux/module.h>
  9
 10#include <linux/time.h>
 11#include <linux/kernel.h>
 12#include <linux/mm.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>
 18#include <linux/fs.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/slab.h>
 25#include <linux/binfmts.h>
 26#include <linux/personality.h>
 27#include <linux/init.h>
 28
 29#include <asm/system.h>
 30#include <asm/uaccess.h>
 31#include <asm/pgalloc.h>
 32#include <asm/cacheflush.h>
 33#include <asm/user32.h>
 34#include <asm/ia32.h>
 35
 36#undef WARN_OLD
 37#undef CORE_DUMP /* probably broken */
 38
 39extern int ia32_setup_arg_pages(struct linux_binprm *bprm,
 40				unsigned long stack_top, int exec_stack);
 41
 42static int load_aout_binary(struct linux_binprm *, struct pt_regs * regs);
 43static int load_aout_library(struct file*);
 44
 45#if CORE_DUMP
 46static int aout_core_dump(long signr, struct pt_regs * regs, struct file *file);
 47
 48/*
 49 * fill in the user structure for a core dump..
 50 */
 51static void dump_thread32(struct pt_regs * regs, struct user32 * dump)
 52{
 53	u32 fs,gs;
 54
 55/* changed the size calculations - should hopefully work better. lbt */
 56	dump->magic = CMAGIC;
 57	dump->start_code = 0;
 58	dump->start_stack = regs->rsp & ~(PAGE_SIZE - 1);
 59	dump->u_tsize = ((unsigned long) current->mm->end_code) >> PAGE_SHIFT;
 60	dump->u_dsize = ((unsigned long) (current->mm->brk + (PAGE_SIZE-1))) >> PAGE_SHIFT;
 61	dump->u_dsize -= dump->u_tsize;
 62	dump->u_ssize = 0;
 63	dump->u_debugreg[0] = current->thread.debugreg0;  
 64	dump->u_debugreg[1] = current->thread.debugreg1;  
 65	dump->u_debugreg[2] = current->thread.debugreg2;  
 66	dump->u_debugreg[3] = current->thread.debugreg3;  
 67	dump->u_debugreg[4] = 0;  
 68	dump->u_debugreg[5] = 0;  
 69	dump->u_debugreg[6] = current->thread.debugreg6;  
 70	dump->u_debugreg[7] = current->thread.debugreg7;  
 71
 72	if (dump->start_stack < 0xc0000000)
 73		dump->u_ssize = ((unsigned long) (0xc0000000 - dump->start_stack)) >> PAGE_SHIFT;
 74
 75	dump->regs.ebx = regs->rbx;
 76	dump->regs.ecx = regs->rcx;
 77	dump->regs.edx = regs->rdx;
 78	dump->regs.esi = regs->rsi;
 79	dump->regs.edi = regs->rdi;
 80	dump->regs.ebp = regs->rbp;
 81	dump->regs.eax = regs->rax;
 82	dump->regs.ds = current->thread.ds;
 83	dump->regs.es = current->thread.es;
 84	asm("movl %%fs,%0" : "=r" (fs)); dump->regs.fs = fs;
 85	asm("movl %%gs,%0" : "=r" (gs)); dump->regs.gs = gs; 
 86	dump->regs.orig_eax = regs->orig_rax;
 87	dump->regs.eip = regs->rip;
 88	dump->regs.cs = regs->cs;
 89	dump->regs.eflags = regs->eflags;
 90	dump->regs.esp = regs->rsp;
 91	dump->regs.ss = regs->ss;
 92
 93#if 1 /* FIXME */
 94	dump->u_fpvalid = 0;
 95#else
 96	dump->u_fpvalid = dump_fpu (regs, &dump->i387);
 97#endif
 98}
 99
100#endif
101
102static struct linux_binfmt aout_format = {
103	.module		= THIS_MODULE,
104	.load_binary	= load_aout_binary,
105	.load_shlib	= load_aout_library,
106#if CORE_DUMP
107	.core_dump	= aout_core_dump,
108#endif
109	.min_coredump	= PAGE_SIZE
110};
111
112static void set_brk(unsigned long start, unsigned long end)
113{
114	start = PAGE_ALIGN(start);
115	end = PAGE_ALIGN(end);
116	if (end <= start)
117		return;
118	down_write(&current->mm->mmap_sem);
119	do_brk(start, end - start);
120	up_write(&current->mm->mmap_sem);
121}
122
123#if CORE_DUMP
124/*
125 * These are the only things you should do on a core-file: use only these
126 * macros to write out all the necessary info.
127 */
128
129static int dump_write(struct file *file, const void *addr, int nr)
130{
131	return file->f_op->write(file, addr, nr, &file->f_pos) == nr;
132}
133
134#define DUMP_WRITE(addr, nr)	\
135	if (!dump_write(file, (void *)(addr), (nr))) \
136		goto end_coredump;
137
138#define DUMP_SEEK(offset) \
139if (file->f_op->llseek) { \
140	if (file->f_op->llseek(file,(offset),0) != (offset)) \
141 		goto end_coredump; \
142} else file->f_pos = (offset)
143
144/*
145 * Routine writes a core dump image in the current directory.
146 * Currently only a stub-function.
147 *
148 * Note that setuid/setgid files won't make a core-dump if the uid/gid
149 * changed due to the set[u|g]id. It's enforced by the "current->mm->dumpable"
150 * field, which also makes sure the core-dumps won't be recursive if the
151 * dumping of the process results in another error..
152 */
153
154static int aout_core_dump(long signr, struct pt_regs * regs, struct file *file)
155{
156	mm_segment_t fs;
157	int has_dumped = 0;
158	unsigned long dump_start, dump_size;
159	struct user32 dump;
160#       define START_DATA(u)	(u.u_tsize << PAGE_SHIFT)
161#       define START_STACK(u)   (u.start_stack)
162
163	fs = get_fs();
164	set_fs(KERNEL_DS);
165	has_dumped = 1;
166	current->flags |= PF_DUMPCORE;
167       	strncpy(dump.u_comm, current->comm, sizeof(current->comm));
168	dump.u_ar0 = (u32)(((unsigned long)(&dump.regs)) - ((unsigned long)(&dump)));
169	dump.signal = signr;
170	dump_thread32(regs, &dump);
171
172/* If the size of the dump file exceeds the rlimit, then see what would happen
173   if we wrote the stack, but not the data area.  */
174	if ((dump.u_dsize+dump.u_ssize+1) * PAGE_SIZE >
175	    current->signal->rlim[RLIMIT_CORE].rlim_cur)
176		dump.u_dsize = 0;
177
178/* Make sure we have enough room to write the stack and data areas. */
179	if ((dump.u_ssize+1) * PAGE_SIZE >
180	    current->signal->rlim[RLIMIT_CORE].rlim_cur)
181		dump.u_ssize = 0;
182
183/* make sure we actually have a data and stack area to dump */
184	set_fs(USER_DS);
185	if (!access_ok(VERIFY_READ, (void *) (unsigned long)START_DATA(dump), dump.u_dsize << PAGE_SHIFT))
186		dump.u_dsize = 0;
187	if (!access_ok(VERIFY_READ, (void *) (unsigned long)START_STACK(dump), dump.u_ssize << PAGE_SHIFT))
188		dump.u_ssize = 0;
189
190	set_fs(KERNEL_DS);
191/* struct user */
192	DUMP_WRITE(&dump,sizeof(dump));
193/* Now dump all of the user data.  Include malloced stuff as well */
194	DUMP_SEEK(PAGE_SIZE);
195/* now we start writing out the user space info */
196	set_fs(USER_DS);
197/* Dump the data area */
198	if (dump.u_dsize != 0) {
199		dump_start = START_DATA(dump);
200		dump_size = dump.u_dsize << PAGE_SHIFT;
201		DUMP_WRITE(dump_start,dump_size);
202	}
203/* Now prepare to dump the stack area */
204	if (dump.u_ssize != 0) {
205		dump_start = START_STACK(dump);
206		dump_size = dump.u_ssize << PAGE_SHIFT;
207		DUMP_WRITE(dump_start,dump_size);
208	}
209/* Finally dump the task struct.  Not be used by gdb, but could be useful */
210	set_fs(KERNEL_DS);
211	DUMP_WRITE(current,sizeof(*current));
212end_coredump:
213	set_fs(fs);
214	return has_dumped;
215}
216#endif
217
218/*
219 * create_aout_tables() parses the env- and arg-strings in new user
220 * memory and creates the pointer tables from them, and puts their
221 * addresses on the "stack", returning the new stack pointer value.
222 */
223static u32 __user *create_aout_tables(char __user *p, struct linux_binprm *bprm)
224{
225	u32 __user *argv;
226	u32 __user *envp;
227	u32 __user *sp;
228	int argc = bprm->argc;
229	int envc = bprm->envc;
230
231	sp = (u32 __user *) ((-(unsigned long)sizeof(u32)) & (unsigned long) p);
232	sp -= envc+1;
233	envp = sp;
234	sp -= argc+1;
235	argv = sp;
236	put_user((unsigned long) envp,--sp);
237	put_user((unsigned long) argv,--sp);
238	put_user(argc,--sp);
239	current->mm->arg_start = (unsigned long) p;
240	while (argc-->0) {
241		char c;
242		put_user((u32)(unsigned long)p,argv++);
243		do {
244			get_user(c,p++);
245		} while (c);
246	}
247	put_user(NULL,argv);
248	current->mm->arg_end = current->mm->env_start = (unsigned long) p;
249	while (envc-->0) {
250		char c;
251		put_user((u32)(unsigned long)p,envp++);
252		do {
253			get_user(c,p++);
254		} while (c);
255	}
256	put_user(NULL,envp);
257	current->mm->env_end = (unsigned long) p;
258	return sp;
259}
260
261/*
262 * These are the functions used to load a.out style executables and shared
263 * libraries.  There is no binary dependent code anywhere else.
264 */
265
266static int load_aout_binary(struct linux_binprm * bprm, struct pt_regs * regs)
267{
268	struct exec ex;
269	unsigned long error;
270	unsigned long fd_offset;
271	unsigned long rlim;
272	int retval;
273
274	ex = *((struct exec *) bprm->buf);		/* exec-header */
275	if ((N_MAGIC(ex) != ZMAGIC && N_MAGIC(ex) != OMAGIC &&
276	     N_MAGIC(ex) != QMAGIC && N_MAGIC(ex) != NMAGIC) ||
277	    N_TRSIZE(ex) || N_DRSIZE(ex) ||
278	    i_size_read(bprm->file->f_dentry->d_inode) < ex.a_text+ex.a_data+N_SYMSIZE(ex)+N_TXTOFF(ex)) {
279		return -ENOEXEC;
280	}
281
282	fd_offset = N_TXTOFF(ex);
283
284	/* Check initial limits. This avoids letting people circumvent
285	 * size limits imposed on them by creating programs with large
286	 * arrays in the data or bss.
287	 */
288	rlim = current->signal->rlim[RLIMIT_DATA].rlim_cur;
289	if (rlim >= RLIM_INFINITY)
290		rlim = ~0;
291	if (ex.a_data + ex.a_bss > rlim)
292		return -ENOMEM;
293
294	/* Flush all traces of the currently running executable */
295	retval = flush_old_exec(bprm);
296	if (retval)
297		return retval;
298
299	regs->cs = __USER32_CS; 
300	regs->r8 = regs->r9 = regs->r10 = regs->r11 = regs->r12 =
301		regs->r13 = regs->r14 = regs->r15 = 0;
302
303	/* OK, This is the point of no return */
304	set_personality(PER_LINUX);
305	set_thread_flag(TIF_IA32); 
306	clear_thread_flag(TIF_ABI_PENDING);
307
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
316	set_mm_counter(current->mm, rss, 0);
317	current->mm->mmap = NULL;
318	compute_creds(bprm);
319 	current->flags &= ~PF_FORKNOEXEC;
320
321	if (N_MAGIC(ex) == OMAGIC) {
322		unsigned long text_addr, map_size;
323		loff_t pos;
324
325		text_addr = N_TXTADDR(ex);
326
327		pos = 32;
328		map_size = ex.a_text+ex.a_data;
329
330		down_write(&current->mm->mmap_sem);
331		error = do_brk(text_addr & PAGE_MASK, map_size);
332		up_write(&current->mm->mmap_sem);
333
334		if (error != (text_addr & PAGE_MASK)) {
335			send_sig(SIGKILL, current, 0);
336			return error;
337		}
338
339		error = bprm->file->f_op->read(bprm->file, (char *)text_addr,
340			  ex.a_text+ex.a_data, &pos);
341		if ((signed long)error < 0) {
342			send_sig(SIGKILL, current, 0);
343			return error;
344		}
345			 
346		flush_icache_range(text_addr, text_addr+ex.a_text+ex.a_data);
347	} else {
348#ifdef WARN_OLD
349		static unsigned long error_time, error_time2;
350		if ((ex.a_text & 0xfff || ex.a_data & 0xfff) &&
351		    (N_MAGIC(ex) != NMAGIC) && (jiffies-error_time2) > 5*HZ)
352		{
353			printk(KERN_NOTICE "executable not page aligned\n");
354			error_time2 = jiffies;
355		}
356
357		if ((fd_offset & ~PAGE_MASK) != 0 &&
358		    (jiffies-error_time) > 5*HZ)
359		{
360			printk(KERN_WARNING 
361			       "fd_offset is not page aligned. Please convert program: %s\n",
362			       bprm->file->f_dentry->d_name.name);
363			error_time = jiffies;
364		}
365#endif
366
367		if (!bprm->file->f_op->mmap||((fd_offset & ~PAGE_MASK) != 0)) {
368			loff_t pos = fd_offset;
369			down_write(&current->mm->mmap_sem);
370			do_brk(N_TXTADDR(ex), ex.a_text+ex.a_data);
371			up_write(&current->mm->mmap_sem);
372			bprm->file->f_op->read(bprm->file,(char *)N_TXTADDR(ex),
373					ex.a_text+ex.a_data, &pos);
374			flush_icache_range((unsigned long) N_TXTADDR(ex),
375					   (unsigned long) N_TXTADDR(ex) +
376					   ex.a_text+ex.a_data);
377			goto beyond_if;
378		}
379
380		down_write(&current->mm->mmap_sem);
381		error = do_mmap(bprm->file, N_TXTADDR(ex), ex.a_text,
382			PROT_READ | PROT_EXEC,
383			MAP_FIXED | MAP_PRIVATE | MAP_DENYWRITE | MAP_EXECUTABLE | MAP_32BIT,
384			fd_offset);
385		up_write(&current->mm->mmap_sem);
386
387		if (error != N_TXTADDR(ex)) {
388			send_sig(SIGKILL, current, 0);
389			return error;
390		}
391
392		down_write(&current->mm->mmap_sem);
393 		error = do_mmap(bprm->file, N_DATADDR(ex), ex.a_data,
394				PROT_READ | PROT_WRITE | PROT_EXEC,
395				MAP_FIXED | MAP_PRIVATE | MAP_DENYWRITE | MAP_EXECUTABLE | MAP_32BIT,
396				fd_offset + ex.a_text);
397		up_write(&current->mm->mmap_sem);
398		if (error != N_DATADDR(ex)) {
399			send_sig(SIGKILL, current, 0);
400			return error;
401		}
402	}
403beyond_if:
404	set_binfmt(&aout_format);
405
406	set_brk(current->mm->start_brk, current->mm->brk);
407
408	retval = ia32_setup_arg_pages(bprm, IA32_STACK_TOP, EXSTACK_DEFAULT);
409	if (retval < 0) { 
410		/* Someone check-me: is this error path enough? */ 
411		send_sig(SIGKILL, current, 0); 
412		return retval;
413	}
414
415	current->mm->start_stack =
416		(unsigned long)create_aout_tables((char __user *)bprm->p, bprm);
417	/* start thread */
418	asm volatile("movl %0,%%fs" :: "r" (0)); \
419	asm volatile("movl %0,%%es; movl %0,%%ds": :"r" (__USER32_DS));
420	load_gs_index(0); 
421	(regs)->rip = ex.a_entry;
422	(regs)->rsp = current->mm->start_stack;
423	(regs)->eflags = 0x200;
424	(regs)->cs = __USER32_CS;
425	(regs)->ss = __USER32_DS;
426	set_fs(USER_DS);
427	if (unlikely(current->ptrace & PT_PTRACED)) {
428		if (current->ptrace & PT_TRACE_EXEC)
429			ptrace_notify ((PTRACE_EVENT_EXEC << 8) | SIGTRAP);
430		else
431			send_sig(SIGTRAP, current, 0);
432	}
433	return 0;
434}
435
436static int load_aout_library(struct file *file)
437{
438	struct inode * inode;
439	unsigned long bss, start_addr, len;
440	unsigned long error;
441	int retval;
442	struct exec ex;
443
444	inode = file->f_dentry->d_inode;
445
446	retval = -ENOEXEC;
447	error = kernel_read(file, 0, (char *) &ex, sizeof(ex));
448	if (error != sizeof(ex))
449		goto out;
450
451	/* We come in here for the regular a.out style of shared libraries */
452	if ((N_MAGIC(ex) != ZMAGIC && N_MAGIC(ex) != QMAGIC) || N_TRSIZE(ex) ||
453	    N_DRSIZE(ex) || ((ex.a_entry & 0xfff) && N_MAGIC(ex) == ZMAGIC) ||
454	    i_size_read(inode) < ex.a_text+ex.a_data+N_SYMSIZE(ex)+N_TXTOFF(ex)) {
455		goto out;
456	}
457
458	if (N_FLAGS(ex))
459		goto out;
460
461	/* For  QMAGIC, the starting address is 0x20 into the page.  We mask
462	   this off to get the starting address for the page */
463
464	start_addr =  ex.a_entry & 0xfffff000;
465
466	if ((N_TXTOFF(ex) & ~PAGE_MASK) != 0) {
467		loff_t pos = N_TXTOFF(ex);
468
469#ifdef WARN_OLD
470		static unsigned long error_time;
471		if ((jiffies-error_time) > 5*HZ)
472		{
473			printk(KERN_WARNING 
474			       "N_TXTOFF is not page aligned. Please convert library: %s\n",
475			       file->f_dentry->d_name.name);
476			error_time = jiffies;
477		}
478#endif
479		down_write(&current->mm->mmap_sem);
480		do_brk(start_addr, ex.a_text + ex.a_data + ex.a_bss);
481		up_write(&current->mm->mmap_sem);
482		
483		file->f_op->read(file, (char *)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 + ex.a_data);
487
488		retval = 0;
489		goto out;
490	}
491	/* Now use mmap to map the library into memory. */
492	down_write(&current->mm->mmap_sem);
493	error = do_mmap(file, start_addr, ex.a_text + ex.a_data,
494			PROT_READ | PROT_WRITE | PROT_EXEC,
495			MAP_FIXED | MAP_PRIVATE | MAP_DENYWRITE | MAP_32BIT,
496			N_TXTOFF(ex));
497	up_write(&current->mm->mmap_sem);
498	retval = error;
499	if (error != start_addr)
500		goto out;
501
502	len = PAGE_ALIGN(ex.a_text + ex.a_data);
503	bss = ex.a_text + ex.a_data + ex.a_bss;
504	if (bss > len) {
505		down_write(&current->mm->mmap_sem);
506		error = do_brk(start_addr + len, bss - len);
507		up_write(&current->mm->mmap_sem);
508		retval = error;
509		if (error != start_addr + len)
510			goto out;
511	}
512	retval = 0;
513out:
514	return retval;
515}
516
517static int __init init_aout_binfmt(void)
518{
519	return register_binfmt(&aout_format);
520}
521
522static void __exit exit_aout_binfmt(void)
523{
524	unregister_binfmt(&aout_format);
525}
526
527module_init(init_aout_binfmt);
528module_exit(exit_aout_binfmt);
529MODULE_LICENSE("GPL");