1 /****************************************************************************/
3 * linux/fs/binfmt_flat.c
5 * Copyright (C) 2000-2003 David McCullough <davidm@snapgear.com>
6 * Copyright (C) 2002 Greg Ungerer <gerg@snapgear.com>
7 * Copyright (C) 2002 SnapGear, by Paul Dale <pauli@snapgear.com>
8 * Copyright (C) 2000, 2001 Lineo, by David McCullough <davidm@lineo.com>
11 * linux/fs/binfmt_aout.c:
12 * Copyright (C) 1991, 1992, 1996 Linus Torvalds
13 * linux/fs/binfmt_flat.c for 2.0 kernel
14 * Copyright (C) 1998 Kenneth Albanowski <kjahds@kjahds.com>
15 * JAN/99 -- coded full program relocation (gerg@snapgear.com)
18 #include <linux/module.h>
19 #include <linux/config.h>
20 #include <linux/kernel.h>
21 #include <linux/sched.h>
23 #include <linux/mman.h>
24 #include <linux/a.out.h>
25 #include <linux/errno.h>
26 #include <linux/signal.h>
27 #include <linux/string.h>
29 #include <linux/file.h>
30 #include <linux/stat.h>
31 #include <linux/fcntl.h>
32 #include <linux/ptrace.h>
33 #include <linux/user.h>
34 #include <linux/slab.h>
35 #include <linux/binfmts.h>
36 #include <linux/personality.h>
37 #include <linux/init.h>
38 #include <linux/flat.h>
40 #include <asm/byteorder.h>
41 #include <asm/system.h>
42 #include <asm/uaccess.h>
43 #include <asm/pgalloc.h>
44 #include <asm/unaligned.h>
45 #include <asm/cacheflush.h>
47 /****************************************************************************/
54 #define DBG_FLT(a...) printk(a)
59 #define RELOC_FAILED 0xff00ff01 /* Relocation incorrect somewhere */
60 #define UNLOADED_LIB 0x7ff000ff /* Placeholder for unused library */
64 unsigned long start_code; /* Start of text segment */
65 unsigned long start_data; /* Start of data segment */
66 unsigned long start_brk; /* End of data segment */
67 unsigned long text_len; /* Length of text segment */
68 unsigned long entry; /* Start address for this module */
69 unsigned long build_date; /* When this one was compiled */
70 short loaded; /* Has this library been loaded? */
71 } lib_list[MAX_SHARED_LIBS];
74 #ifdef CONFIG_BINFMT_SHARED_FLAT
75 static int load_flat_shared_library(int id, struct lib_info *p);
78 static int load_flat_binary(struct linux_binprm *, struct pt_regs * regs);
79 static int flat_core_dump(long signr, struct pt_regs * regs, struct file *file);
81 extern void dump_thread(struct pt_regs *, struct user *);
83 static struct linux_binfmt flat_format = {
84 .module = THIS_MODULE,
85 .load_binary = load_flat_binary,
86 .core_dump = flat_core_dump,
87 .min_coredump = PAGE_SIZE
90 /****************************************************************************/
92 * Routine writes a core dump image in the current directory.
93 * Currently only a stub-function.
96 static int flat_core_dump(long signr, struct pt_regs * regs, struct file *file)
98 printk("Process %s:%d received signr %d and should have core dumped\n",
99 current->comm, current->pid, (int) signr);
103 /****************************************************************************/
105 * create_flat_tables() parses the env- and arg-strings in new user
106 * memory and creates the pointer tables from them, and puts their
107 * addresses on the "stack", returning the new stack pointer value.
110 static unsigned long create_flat_tables(
112 struct linux_binprm * bprm)
114 unsigned long *argv,*envp;
116 char * p = (char*)pp;
117 int argc = bprm->argc;
118 int envc = bprm->envc;
121 sp = (unsigned long *) ((-(unsigned long)sizeof(char *))&(unsigned long) p);
128 flat_stack_align(sp);
129 if (flat_argvp_envp_on_stack()) {
130 --sp; put_user((unsigned long) envp, sp);
131 --sp; put_user((unsigned long) argv, sp);
135 current->mm->arg_start = (unsigned long) p;
137 put_user((unsigned long) p, argv++);
139 get_user(dummy, p); p++;
142 put_user((unsigned long) NULL, argv);
143 current->mm->arg_end = current->mm->env_start = (unsigned long) p;
145 put_user((unsigned long)p, envp); envp++;
147 get_user(dummy, p); p++;
150 put_user((unsigned long) NULL, envp);
151 current->mm->env_end = (unsigned long) p;
152 return (unsigned long)sp;
155 /****************************************************************************/
157 #ifdef CONFIG_BINFMT_ZFLAT
159 #include <linux/zlib.h>
161 #define LBUFSIZE 4000
164 #define ASCII_FLAG 0x01 /* bit 0 set: file probably ASCII text */
165 #define CONTINUATION 0x02 /* bit 1 set: continuation of multi-part gzip file */
166 #define EXTRA_FIELD 0x04 /* bit 2 set: extra field present */
167 #define ORIG_NAME 0x08 /* bit 3 set: original file name present */
168 #define COMMENT 0x10 /* bit 4 set: file comment present */
169 #define ENCRYPTED 0x20 /* bit 5 set: file is encrypted */
170 #define RESERVED 0xC0 /* bit 6,7: reserved */
172 static int decompress_exec(
173 struct linux_binprm *bprm,
174 unsigned long offset,
184 DBG_FLT("decompress_exec(offset=%x,buf=%x,len=%x)\n",(int)offset, (int)dst, (int)len);
186 memset(&strm, 0, sizeof(strm));
187 strm.workspace = kmalloc(zlib_inflate_workspacesize(), GFP_KERNEL);
188 if (strm.workspace == NULL) {
189 DBG_FLT("binfmt_flat: no memory for decompress workspace\n");
192 buf = kmalloc(LBUFSIZE, GFP_KERNEL);
194 DBG_FLT("binfmt_flat: no memory for read buffer\n");
198 /* Read in first chunk of data and parse gzip header. */
200 ret = bprm->file->f_op->read(bprm->file, buf, LBUFSIZE, &fpos);
206 /* Check minimum size -- gzip header */
208 DBG_FLT("binfmt_flat: file too small?\n");
212 /* Check gzip magic number */
213 if ((buf[0] != 037) || ((buf[1] != 0213) && (buf[1] != 0236))) {
214 DBG_FLT("binfmt_flat: unknown compression magic?\n");
218 /* Check gzip method */
220 DBG_FLT("binfmt_flat: unknown compression method?\n");
223 /* Check gzip flags */
224 if ((buf[3] & ENCRYPTED) || (buf[3] & CONTINUATION) ||
225 (buf[3] & RESERVED)) {
226 DBG_FLT("binfmt_flat: unknown flags?\n");
231 if (buf[3] & EXTRA_FIELD) {
232 ret += 2 + buf[10] + (buf[11] << 8);
233 if (unlikely(LBUFSIZE == ret)) {
234 DBG_FLT("binfmt_flat: buffer overflow (EXTRA)?\n");
238 if (buf[3] & ORIG_NAME) {
239 for (; ret < LBUFSIZE && (buf[ret] != 0); ret++)
241 if (unlikely(LBUFSIZE == ret)) {
242 DBG_FLT("binfmt_flat: buffer overflow (ORIG_NAME)?\n");
246 if (buf[3] & COMMENT) {
247 for (; ret < LBUFSIZE && (buf[ret] != 0); ret++)
249 if (unlikely(LBUFSIZE == ret)) {
250 DBG_FLT("binfmt_flat: buffer overflow (COMMENT)?\n");
256 strm.avail_in -= ret;
259 strm.avail_out = len;
262 if (zlib_inflateInit2(&strm, -MAX_WBITS) != Z_OK) {
263 DBG_FLT("binfmt_flat: zlib init failed?\n");
267 while ((ret = zlib_inflate(&strm, Z_NO_FLUSH)) == Z_OK) {
268 ret = bprm->file->f_op->read(bprm->file, buf, LBUFSIZE, &fpos);
271 if (ret >= (unsigned long) -4096)
281 DBG_FLT("binfmt_flat: decompression failed (%d), %s\n",
286 zlib_inflateEnd(&strm);
288 kfree(strm.workspace);
292 #endif /* CONFIG_BINFMT_ZFLAT */
294 /****************************************************************************/
297 calc_reloc(unsigned long r, struct lib_info *p, int curid, int internalp)
301 unsigned long start_brk;
302 unsigned long start_data;
303 unsigned long text_len;
304 unsigned long start_code;
306 #ifdef CONFIG_BINFMT_SHARED_FLAT
308 id = curid; /* Relocs of 0 are always self referring */
310 id = (r >> 24) & 0xff; /* Find ID for this reloc */
311 r &= 0x00ffffff; /* Trim ID off here */
313 if (id >= MAX_SHARED_LIBS) {
314 printk("BINFMT_FLAT: reference 0x%x to shared library %d",
320 printk("BINFMT_FLAT: reloc address 0x%x not in same module "
321 "(%d != %d)", (unsigned) r, curid, id);
323 } else if ( ! p->lib_list[id].loaded &&
324 load_flat_shared_library(id, p) > (unsigned long) -4096) {
325 printk("BINFMT_FLAT: failed to load library %d", id);
328 /* Check versioning information (i.e. time stamps) */
329 if (p->lib_list[id].build_date && p->lib_list[curid].build_date &&
330 p->lib_list[curid].build_date < p->lib_list[id].build_date) {
331 printk("BINFMT_FLAT: library %d is younger than %d", id, curid);
339 start_brk = p->lib_list[id].start_brk;
340 start_data = p->lib_list[id].start_data;
341 start_code = p->lib_list[id].start_code;
342 text_len = p->lib_list[id].text_len;
344 if (!flat_reloc_valid(r, start_brk - start_data + text_len)) {
345 printk("BINFMT_FLAT: reloc outside program 0x%x (0 - 0x%x/0x%x)",
346 (int) r,(int)(start_brk-start_code),(int)text_len);
350 if (r < text_len) /* In text segment */
351 addr = r + start_code;
352 else /* In data segment */
353 addr = r - text_len + start_data;
355 /* Range checked already above so doing the range tests is redundant...*/
359 printk(", killing %s!\n", current->comm);
360 send_sig(SIGSEGV, current, 0);
365 /****************************************************************************/
367 void old_reloc(unsigned long rl)
370 char *segment[] = { "TEXT", "DATA", "BSS", "*UNKNOWN*" };
376 #if defined(CONFIG_COLDFIRE)
377 ptr = (unsigned long *) (current->mm->start_code + r.reloc.offset);
379 ptr = (unsigned long *) (current->mm->start_data + r.reloc.offset);
383 printk("Relocation of variable at DATASEG+%x "
384 "(address %p, currently %x) into segment %s\n",
385 r.reloc.offset, ptr, (int)*ptr, segment[r.reloc.type]);
388 switch (r.reloc.type) {
389 case OLD_FLAT_RELOC_TYPE_TEXT:
390 *ptr += current->mm->start_code;
392 case OLD_FLAT_RELOC_TYPE_DATA:
393 *ptr += current->mm->start_data;
395 case OLD_FLAT_RELOC_TYPE_BSS:
396 *ptr += current->mm->end_data;
399 printk("BINFMT_FLAT: Unknown relocation type=%x\n", r.reloc.type);
404 printk("Relocation became %x\n", (int)*ptr);
408 /****************************************************************************/
410 static int load_flat_file(struct linux_binprm * bprm,
411 struct lib_info *libinfo, int id, unsigned long *extra_stack)
413 struct flat_hdr * hdr;
414 unsigned long textpos = 0, datapos = 0, result;
415 unsigned long realdatastart = 0;
416 unsigned long text_len, data_len, bss_len, stack_len, flags;
417 unsigned long memp = 0; /* for finding the brk area */
418 unsigned long extra, rlim;
419 unsigned long *reloc = 0, *rp;
421 int i, rev, relocs = 0;
423 unsigned long start_code, end_code;
425 hdr = ((struct flat_hdr *) bprm->buf); /* exec-header */
426 inode = bprm->file->f_dentry->d_inode;
428 text_len = ntohl(hdr->data_start);
429 data_len = ntohl(hdr->data_end) - ntohl(hdr->data_start);
430 bss_len = ntohl(hdr->bss_end) - ntohl(hdr->data_end);
431 stack_len = ntohl(hdr->stack_size);
433 stack_len += *extra_stack;
434 *extra_stack = stack_len;
436 relocs = ntohl(hdr->reloc_count);
437 flags = ntohl(hdr->flags);
438 rev = ntohl(hdr->rev);
440 if (flags & FLAT_FLAG_KTRACE)
441 printk("BINFMT_FLAT: Loading file: %s\n", bprm->filename);
443 if (strncmp(hdr->magic, "bFLT", 4) ||
444 (rev != FLAT_VERSION && rev != OLD_FLAT_VERSION)) {
446 * because a lot of people do not manage to produce good
447 * flat binaries, we leave this printk to help them realise
448 * the problem. We only print the error if its not a script file
450 if (strncmp(hdr->magic, "#!", 2))
451 printk("BINFMT_FLAT: bad magic/rev (0x%x, need 0x%x)\n",
452 rev, (int) FLAT_VERSION);
456 /* Don't allow old format executables to use shared libraries */
457 if (rev == OLD_FLAT_VERSION && id != 0) {
458 printk("BINFMT_FLAT: shared libraries are not available before rev 0x%x\n",
464 * fix up the flags for the older format, there were all kinds
465 * of endian hacks, this only works for the simple cases
467 if (rev == OLD_FLAT_VERSION && flat_old_ram_flag(flags))
468 flags = FLAT_FLAG_RAM;
470 #ifndef CONFIG_BINFMT_ZFLAT
471 if (flags & (FLAT_FLAG_GZIP|FLAT_FLAG_GZDATA)) {
472 printk("Support for ZFLAT executables is not enabled.\n");
478 * Check initial limits. This avoids letting people circumvent
479 * size limits imposed on them by creating programs with large
480 * arrays in the data or bss.
482 rlim = current->rlim[RLIMIT_DATA].rlim_cur;
483 if (rlim >= RLIM_INFINITY)
485 if (data_len + bss_len > rlim)
488 /* Flush all traces of the currently running executable */
490 result = flush_old_exec(bprm);
494 /* OK, This is the point of no return */
495 set_personality(PER_LINUX);
499 * calculate the extra space we need to map in
501 extra = max(bss_len + stack_len, relocs * sizeof(unsigned long));
504 * there are a couple of cases here, the separate code/data
505 * case, and then the fully copied to RAM case which lumps
508 if ((flags & (FLAT_FLAG_RAM|FLAT_FLAG_GZIP)) == 0) {
510 * this should give us a ROM ptr, but if it doesn't we don't
513 DBG_FLT("BINFMT_FLAT: ROM mapping of file (we hope)\n");
515 down_write(¤t->mm->mmap_sem);
516 textpos = do_mmap(bprm->file, 0, text_len, PROT_READ|PROT_EXEC, 0, 0);
517 up_write(¤t->mm->mmap_sem);
518 if (!textpos || textpos >= (unsigned long) -4096) {
520 textpos = (unsigned long) -ENOMEM;
521 printk("Unable to mmap process text, errno %d\n", (int)-textpos);
525 down_write(¤t->mm->mmap_sem);
526 realdatastart = do_mmap(0, 0, data_len + extra +
527 MAX_SHARED_LIBS * sizeof(unsigned long),
528 PROT_READ|PROT_WRITE|PROT_EXEC, 0, 0);
529 up_write(¤t->mm->mmap_sem);
531 if (realdatastart == 0 || realdatastart >= (unsigned long)-4096) {
533 realdatastart = (unsigned long) -ENOMEM;
534 printk("Unable to allocate RAM for process data, errno %d\n",
536 do_munmap(current->mm, textpos, text_len);
537 return realdatastart;
539 datapos = realdatastart + MAX_SHARED_LIBS * sizeof(unsigned long);
541 DBG_FLT("BINFMT_FLAT: Allocated data+bss+stack (%d bytes): %x\n",
542 (int)(data_len + bss_len + stack_len), (int)datapos);
544 fpos = ntohl(hdr->data_start);
545 #ifdef CONFIG_BINFMT_ZFLAT
546 if (flags & FLAT_FLAG_GZDATA) {
547 result = decompress_exec(bprm, fpos, (char *) datapos,
548 data_len + (relocs * sizeof(unsigned long)), 0);
552 result = bprm->file->f_op->read(bprm->file, (char *) datapos,
553 data_len + (relocs * sizeof(unsigned long)), &fpos);
555 if (result >= (unsigned long)-4096) {
556 printk("Unable to read data+bss, errno %d\n", (int)-result);
557 do_munmap(current->mm, textpos, text_len);
558 do_munmap(current->mm, realdatastart, data_len + extra);
562 reloc = (unsigned long *) (datapos+(ntohl(hdr->reloc_start)-text_len));
563 memp = realdatastart;
567 down_write(¤t->mm->mmap_sem);
568 textpos = do_mmap(0, 0, text_len + data_len + extra +
569 MAX_SHARED_LIBS * sizeof(unsigned long),
570 PROT_READ | PROT_EXEC | PROT_WRITE, 0, 0);
571 up_write(¤t->mm->mmap_sem);
572 if (!textpos || textpos >= (unsigned long) -4096) {
574 textpos = (unsigned long) -ENOMEM;
575 printk("Unable to allocate RAM for process text/data, errno %d\n",
580 realdatastart = textpos + ntohl(hdr->data_start);
581 datapos = realdatastart + MAX_SHARED_LIBS * sizeof(unsigned long);
582 reloc = (unsigned long *) (textpos + ntohl(hdr->reloc_start) +
583 MAX_SHARED_LIBS * sizeof(unsigned long));
586 #ifdef CONFIG_BINFMT_ZFLAT
588 * load it all in and treat it like a RAM load from now on
590 if (flags & FLAT_FLAG_GZIP) {
591 result = decompress_exec(bprm, sizeof (struct flat_hdr),
592 (((char *) textpos) + sizeof (struct flat_hdr)),
593 (text_len + data_len + (relocs * sizeof(unsigned long))
594 - sizeof (struct flat_hdr)),
596 memmove((void *) datapos, (void *) realdatastart,
597 data_len + (relocs * sizeof(unsigned long)));
598 } else if (flags & FLAT_FLAG_GZDATA) {
600 result = bprm->file->f_op->read(bprm->file,
601 (char *) textpos, text_len, &fpos);
602 if (result < (unsigned long) -4096)
603 result = decompress_exec(bprm, text_len, (char *) datapos,
604 data_len + (relocs * sizeof(unsigned long)), 0);
610 result = bprm->file->f_op->read(bprm->file,
611 (char *) textpos, text_len, &fpos);
612 if (result < (unsigned long) -4096) {
613 fpos = ntohl(hdr->data_start);
614 result = bprm->file->f_op->read(bprm->file, (char *) datapos,
615 data_len + (relocs * sizeof(unsigned long)), &fpos);
618 if (result >= (unsigned long)-4096) {
619 printk("Unable to read code+data+bss, errno %d\n",(int)-result);
620 do_munmap(current->mm, textpos, text_len + data_len + extra +
621 MAX_SHARED_LIBS * sizeof(unsigned long));
626 if (flags & FLAT_FLAG_KTRACE)
627 printk("Mapping is %x, Entry point is %x, data_start is %x\n",
628 (int)textpos, 0x00ffffff&ntohl(hdr->entry), ntohl(hdr->data_start));
630 /* The main program needs a little extra setup in the task structure */
631 start_code = textpos + sizeof (struct flat_hdr);
632 end_code = textpos + text_len;
634 current->mm->start_code = start_code;
635 current->mm->end_code = end_code;
636 current->mm->start_data = datapos;
637 current->mm->end_data = datapos + data_len;
639 * set up the brk stuff, uses any slack left in data/bss/stack
640 * allocation. We put the brk after the bss (between the bss
641 * and stack) like other platforms.
643 current->mm->start_brk = datapos + data_len + bss_len;
644 current->mm->brk = (current->mm->start_brk + 3) & ~3;
645 current->mm->context.end_brk = memp + ksize((void *) memp) - stack_len;
646 current->mm->rss = 0;
649 if (flags & FLAT_FLAG_KTRACE)
650 printk("%s %s: TEXT=%x-%x DATA=%x-%x BSS=%x-%x\n",
651 id ? "Lib" : "Load", bprm->filename,
652 (int) start_code, (int) end_code,
654 (int) (datapos + data_len),
655 (int) (datapos + data_len),
656 (int) (((datapos + data_len + bss_len) + 3) & ~3));
658 text_len -= sizeof(struct flat_hdr); /* the real code len */
660 /* Store the current module values into the global library structure */
661 libinfo->lib_list[id].start_code = start_code;
662 libinfo->lib_list[id].start_data = datapos;
663 libinfo->lib_list[id].start_brk = datapos + data_len + bss_len;
664 libinfo->lib_list[id].text_len = text_len;
665 libinfo->lib_list[id].loaded = 1;
666 libinfo->lib_list[id].entry = (0x00ffffff & ntohl(hdr->entry)) + textpos;
667 libinfo->lib_list[id].build_date = ntohl(hdr->build_date);
670 * We just load the allocations into some temporary memory to
671 * help simplify all this mumbo jumbo
673 * We've got two different sections of relocation entries.
674 * The first is the GOT which resides at the begining of the data segment
675 * and is terminated with a -1. This one can be relocated in place.
676 * The second is the extra relocation entries tacked after the image's
677 * data segment. These require a little more processing as the entry is
678 * really an offset into the image which contains an offset into the
681 if (flags & FLAT_FLAG_GOTPIC) {
682 for (rp = (unsigned long *)datapos; *rp != 0xffffffff; rp++) {
685 addr = calc_reloc(*rp, libinfo, id, 0);
686 if (addr == RELOC_FAILED)
694 * Now run through the relocation entries.
695 * We've got to be careful here as C++ produces relocatable zero
696 * entries in the constructor and destructor tables which are then
697 * tested for being not zero (which will always occur unless we're
698 * based from address zero). This causes an endless loop as __start
699 * is at zero. The solution used is to not relocate zero addresses.
700 * This has the negative side effect of not allowing a global data
701 * reference to be statically initialised to _stext (I've moved
702 * __start to address 4 so that is okay).
704 if (rev > OLD_FLAT_VERSION) {
705 for (i=0; i < relocs; i++) {
706 unsigned long addr, relval;
708 /* Get the address of the pointer to be
709 relocated (of course, the address has to be
711 relval = ntohl(reloc[i]);
712 addr = flat_get_relocate_addr(relval);
713 rp = (unsigned long *) calc_reloc(addr, libinfo, id, 1);
714 if (rp == (unsigned long *)RELOC_FAILED)
717 /* Get the pointer's value. */
718 addr = flat_get_addr_from_rp(rp, relval);
721 * Do the relocation. PIC relocs in the data section are
722 * already in target order
724 if ((flags & FLAT_FLAG_GOTPIC) == 0)
726 addr = calc_reloc(addr, libinfo, id, 0);
727 if (addr == RELOC_FAILED)
730 /* Write back the relocated pointer. */
731 flat_put_addr_at_rp(rp, addr, relval);
735 for (i=0; i < relocs; i++)
736 old_reloc(ntohl(reloc[i]));
739 flush_icache_range(start_code, end_code);
741 /* zero the BSS, BRK and stack areas */
742 memset((void*)(datapos + data_len), 0, bss_len +
743 (memp + ksize((void *) memp) - stack_len - /* end brk */
744 libinfo->lib_list[id].start_brk) + /* start brk */
751 /****************************************************************************/
752 #ifdef CONFIG_BINFMT_SHARED_FLAT
755 * Load a shared library into memory. The library gets its own data
756 * segment (including bss) but not argv/argc/environ.
759 static int load_flat_shared_library(int id, struct lib_info *libs)
761 struct linux_binprm bprm;
765 /* Create the file name */
766 sprintf(buf, "/lib/lib%d.so", id);
768 /* Open the file up */
770 bprm.file = open_exec(bprm.filename);
771 res = PTR_ERR(bprm.file);
772 if (IS_ERR(bprm.file))
775 res = prepare_binprm(&bprm);
777 if (res <= (unsigned long)-4096)
778 res = load_flat_file(&bprm, libs, id, NULL);
780 allow_write_access(bprm.file);
787 #endif /* CONFIG_BINFMT_SHARED_FLAT */
788 /****************************************************************************/
791 * These are the functions used to load flat style executables and shared
792 * libraries. There is no binary dependent code anywhere else.
795 static int load_flat_binary(struct linux_binprm * bprm, struct pt_regs * regs)
797 struct lib_info libinfo;
798 unsigned long p = bprm->p;
799 unsigned long stack_len;
800 unsigned long start_addr;
805 memset(&libinfo, 0, sizeof(libinfo));
807 * We have to add the size of our arguments to our stack size
808 * otherwise it's too easy for users to create stack overflows
809 * by passing in a huge argument list. And yes, we have to be
810 * pedantic and include space for the argv/envp array as it may have
813 #define TOP_OF_ARGS (PAGE_SIZE * MAX_ARG_PAGES - sizeof(void *))
814 stack_len = TOP_OF_ARGS - bprm->p; /* the strings */
815 stack_len += (bprm->argc + 1) * sizeof(char *); /* the argv array */
816 stack_len += (bprm->envc + 1) * sizeof(char *); /* the envp array */
819 res = load_flat_file(bprm, &libinfo, 0, &stack_len);
820 if (res > (unsigned long)-4096)
823 /* Update data segment pointers for all libraries */
824 for (i=0; i<MAX_SHARED_LIBS; i++)
825 if (libinfo.lib_list[i].loaded)
826 for (j=0; j<MAX_SHARED_LIBS; j++)
827 (-(j+1))[(unsigned long *)(libinfo.lib_list[i].start_data)] =
828 (libinfo.lib_list[j].loaded)?
829 libinfo.lib_list[j].start_data:UNLOADED_LIB;
832 current->flags &= ~PF_FORKNOEXEC;
834 set_binfmt(&flat_format);
836 p = ((current->mm->context.end_brk + stack_len + 3) & ~3) - 4;
837 DBG_FLT("p=%x\n", (int)p);
839 /* copy the arg pages onto the stack, this could be more efficient :-) */
840 for (i = TOP_OF_ARGS - 1; i >= bprm->p; i--)
842 ((char *) page_address(bprm->page[i/PAGE_SIZE]))[i % PAGE_SIZE];
844 sp = (unsigned long *) create_flat_tables(p, bprm);
846 /* Fake some return addresses to ensure the call chain will
847 * initialise library in order for us. We are required to call
848 * lib 1 first, then 2, ... and finally the main program (id 0).
850 start_addr = libinfo.lib_list[0].entry;
852 #ifdef CONFIG_BINFMT_SHARED_FLAT
853 for (i = MAX_SHARED_LIBS-1; i>0; i--) {
854 if (libinfo.lib_list[i].loaded) {
855 /* Push previos first to call address */
856 --sp; put_user(start_addr, sp);
857 start_addr = libinfo.lib_list[i].entry;
862 /* Stash our initial stack pointer into the mm structure */
863 current->mm->start_stack = (unsigned long )sp;
866 DBG_FLT("start_thread(regs=0x%x, entry=0x%x, start_stack=0x%x)\n",
867 (int)regs, (int)start_addr, (int)current->mm->start_stack);
869 start_thread(regs, start_addr, current->mm->start_stack);
871 if (current->ptrace & PT_PTRACED)
872 send_sig(SIGTRAP, current, 0);
877 /****************************************************************************/
879 static int __init init_flat_binfmt(void)
881 return register_binfmt(&flat_format);
884 static void __exit exit_flat_binfmt(void)
886 unregister_binfmt(&flat_format);
889 /****************************************************************************/
891 module_init(init_flat_binfmt);
892 module_exit(exit_flat_binfmt);
894 /****************************************************************************/