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 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
20 #include <linux/kernel.h>
21 #include <linux/sched.h>
23 #include <linux/mman.h>
24 #include <linux/errno.h>
25 #include <linux/signal.h>
26 #include <linux/string.h>
28 #include <linux/file.h>
29 #include <linux/ptrace.h>
30 #include <linux/user.h>
31 #include <linux/slab.h>
32 #include <linux/binfmts.h>
33 #include <linux/personality.h>
34 #include <linux/init.h>
35 #include <linux/flat.h>
36 #include <linux/uaccess.h>
38 #include <asm/byteorder.h>
39 #include <asm/unaligned.h>
40 #include <asm/cacheflush.h>
43 /****************************************************************************/
46 * User data (data section and bss) needs to be aligned.
47 * We pick 0x20 here because it is the max value elf2flt has always
48 * used in producing FLAT files, and because it seems to be large
49 * enough to make all the gcc alignment related tests happy.
51 #define FLAT_DATA_ALIGN (0x20)
54 * User data (stack) also needs to be aligned.
55 * Here we can be a bit looser than the data sections since this
56 * needs to only meet arch ABI requirements.
58 #define FLAT_STACK_ALIGN max_t(unsigned long, sizeof(void *), ARCH_SLAB_MINALIGN)
60 #define RELOC_FAILED 0xff00ff01 /* Relocation incorrect somewhere */
61 #define UNLOADED_LIB 0x7ff000ff /* Placeholder for unused library */
65 unsigned long start_code; /* Start of text segment */
66 unsigned long start_data; /* Start of data segment */
67 unsigned long start_brk; /* End of data segment */
68 unsigned long text_len; /* Length of text segment */
69 unsigned long entry; /* Start address for this module */
70 unsigned long build_date; /* When this one was compiled */
71 bool loaded; /* Has this library been loaded? */
72 } lib_list[MAX_SHARED_LIBS];
75 #ifdef CONFIG_BINFMT_SHARED_FLAT
76 static int load_flat_shared_library(int id, struct lib_info *p);
79 static int load_flat_binary(struct linux_binprm *);
80 static int flat_core_dump(struct coredump_params *cprm);
82 static struct linux_binfmt flat_format = {
83 .module = THIS_MODULE,
84 .load_binary = load_flat_binary,
85 .core_dump = flat_core_dump,
86 .min_coredump = PAGE_SIZE
89 /****************************************************************************/
91 * Routine writes a core dump image in the current directory.
92 * Currently only a stub-function.
95 static int flat_core_dump(struct coredump_params *cprm)
97 pr_warn("Process %s:%d received signr %d and should have core dumped\n",
98 current->comm, current->pid, cprm->siginfo->si_signo);
102 /****************************************************************************/
104 * create_flat_tables() parses the env- and arg-strings in new user
105 * memory and creates the pointer tables from them, and puts their
106 * addresses on the "stack", recording the new stack pointer value.
109 static int create_flat_tables(struct linux_binprm *bprm, unsigned long arg_start)
112 unsigned long __user *sp;
115 p = (char __user *)arg_start;
116 sp = (unsigned long __user *)current->mm->start_stack;
118 sp -= bprm->envc + 1;
119 sp -= bprm->argc + 1;
120 sp -= flat_argvp_envp_on_stack() ? 2 : 0;
123 current->mm->start_stack = (unsigned long)sp & -FLAT_STACK_ALIGN;
124 sp = (unsigned long __user *)current->mm->start_stack;
126 __put_user(bprm->argc, sp++);
127 if (flat_argvp_envp_on_stack()) {
128 unsigned long argv, envp;
129 argv = (unsigned long)(sp + 2);
130 envp = (unsigned long)(sp + 2 + bprm->argc + 1);
131 __put_user(argv, sp++);
132 __put_user(envp, sp++);
135 current->mm->arg_start = (unsigned long)p;
136 for (i = bprm->argc; i > 0; i--) {
137 __put_user((unsigned long)p, sp++);
138 len = strnlen_user(p, MAX_ARG_STRLEN);
139 if (!len || len > MAX_ARG_STRLEN)
144 current->mm->arg_end = (unsigned long)p;
146 current->mm->env_start = (unsigned long) p;
147 for (i = bprm->envc; i > 0; i--) {
148 __put_user((unsigned long)p, sp++);
149 len = strnlen_user(p, MAX_ARG_STRLEN);
150 if (!len || len > MAX_ARG_STRLEN)
155 current->mm->env_end = (unsigned long)p;
160 /****************************************************************************/
162 #ifdef CONFIG_BINFMT_ZFLAT
164 #include <linux/zlib.h>
166 #define LBUFSIZE 4000
169 #define ASCII_FLAG 0x01 /* bit 0 set: file probably ASCII text */
170 #define CONTINUATION 0x02 /* bit 1 set: continuation of multi-part gzip file */
171 #define EXTRA_FIELD 0x04 /* bit 2 set: extra field present */
172 #define ORIG_NAME 0x08 /* bit 3 set: original file name present */
173 #define COMMENT 0x10 /* bit 4 set: file comment present */
174 #define ENCRYPTED 0x20 /* bit 5 set: file is encrypted */
175 #define RESERVED 0xC0 /* bit 6,7: reserved */
177 static int decompress_exec(
178 struct linux_binprm *bprm,
179 unsigned long offset,
189 pr_debug("decompress_exec(offset=%lx,buf=%p,len=%lx)\n", offset, dst, len);
191 memset(&strm, 0, sizeof(strm));
192 strm.workspace = kmalloc(zlib_inflate_workspacesize(), GFP_KERNEL);
193 if (strm.workspace == NULL) {
194 pr_debug("no memory for decompress workspace\n");
197 buf = kmalloc(LBUFSIZE, GFP_KERNEL);
199 pr_debug("no memory for read buffer\n");
204 /* Read in first chunk of data and parse gzip header. */
206 ret = kernel_read(bprm->file, offset, buf, LBUFSIZE);
215 /* Check minimum size -- gzip header */
217 pr_debug("file too small?\n");
221 /* Check gzip magic number */
222 if ((buf[0] != 037) || ((buf[1] != 0213) && (buf[1] != 0236))) {
223 pr_debug("unknown compression magic?\n");
227 /* Check gzip method */
229 pr_debug("unknown compression method?\n");
232 /* Check gzip flags */
233 if ((buf[3] & ENCRYPTED) || (buf[3] & CONTINUATION) ||
234 (buf[3] & RESERVED)) {
235 pr_debug("unknown flags?\n");
240 if (buf[3] & EXTRA_FIELD) {
241 ret += 2 + buf[10] + (buf[11] << 8);
242 if (unlikely(ret >= LBUFSIZE)) {
243 pr_debug("buffer overflow (EXTRA)?\n");
247 if (buf[3] & ORIG_NAME) {
248 while (ret < LBUFSIZE && buf[ret++] != 0)
250 if (unlikely(ret == LBUFSIZE)) {
251 pr_debug("buffer overflow (ORIG_NAME)?\n");
255 if (buf[3] & COMMENT) {
256 while (ret < LBUFSIZE && buf[ret++] != 0)
258 if (unlikely(ret == LBUFSIZE)) {
259 pr_debug("buffer overflow (COMMENT)?\n");
265 strm.avail_in -= ret;
268 strm.avail_out = len;
271 if (zlib_inflateInit2(&strm, -MAX_WBITS) != Z_OK) {
272 pr_debug("zlib init failed?\n");
276 while ((ret = zlib_inflate(&strm, Z_NO_FLUSH)) == Z_OK) {
277 ret = kernel_read(bprm->file, fpos, buf, LBUFSIZE);
289 pr_debug("decompression failed (%d), %s\n",
296 zlib_inflateEnd(&strm);
300 kfree(strm.workspace);
304 #endif /* CONFIG_BINFMT_ZFLAT */
306 /****************************************************************************/
309 calc_reloc(unsigned long r, struct lib_info *p, int curid, int internalp)
313 unsigned long start_brk;
314 unsigned long start_data;
315 unsigned long text_len;
316 unsigned long start_code;
318 #ifdef CONFIG_BINFMT_SHARED_FLAT
320 id = curid; /* Relocs of 0 are always self referring */
322 id = (r >> 24) & 0xff; /* Find ID for this reloc */
323 r &= 0x00ffffff; /* Trim ID off here */
325 if (id >= MAX_SHARED_LIBS) {
326 pr_err("reference 0x%lx to shared library %d", r, id);
331 pr_err("reloc address 0x%lx not in same module "
332 "(%d != %d)", r, curid, id);
334 } else if (!p->lib_list[id].loaded &&
335 load_flat_shared_library(id, p) < 0) {
336 pr_err("failed to load library %d", id);
339 /* Check versioning information (i.e. time stamps) */
340 if (p->lib_list[id].build_date && p->lib_list[curid].build_date &&
341 p->lib_list[curid].build_date < p->lib_list[id].build_date) {
342 pr_err("library %d is younger than %d", id, curid);
350 start_brk = p->lib_list[id].start_brk;
351 start_data = p->lib_list[id].start_data;
352 start_code = p->lib_list[id].start_code;
353 text_len = p->lib_list[id].text_len;
355 if (!flat_reloc_valid(r, start_brk - start_data + text_len)) {
356 pr_err("reloc outside program 0x%lx (0 - 0x%lx/0x%lx)",
357 r, start_brk-start_data+text_len, text_len);
361 if (r < text_len) /* In text segment */
362 addr = r + start_code;
363 else /* In data segment */
364 addr = r - text_len + start_data;
366 /* Range checked already above so doing the range tests is redundant...*/
370 pr_cont(", killing %s!\n", current->comm);
371 send_sig(SIGSEGV, current, 0);
376 /****************************************************************************/
378 static void old_reloc(unsigned long rl)
380 static const char *segment[] = { "TEXT", "DATA", "BSS", "*UNKNOWN*" };
382 unsigned long __user *ptr;
386 #if defined(CONFIG_COLDFIRE)
387 ptr = (unsigned long __user *)(current->mm->start_code + r.reloc.offset);
389 ptr = (unsigned long __user *)(current->mm->start_data + r.reloc.offset);
393 pr_debug("Relocation of variable at DATASEG+%x "
394 "(address %p, currently %lx) into segment %s\n",
395 r.reloc.offset, ptr, val, segment[r.reloc.type]);
397 switch (r.reloc.type) {
398 case OLD_FLAT_RELOC_TYPE_TEXT:
399 val += current->mm->start_code;
401 case OLD_FLAT_RELOC_TYPE_DATA:
402 val += current->mm->start_data;
404 case OLD_FLAT_RELOC_TYPE_BSS:
405 val += current->mm->end_data;
408 pr_err("Unknown relocation type=%x\n", r.reloc.type);
413 pr_debug("Relocation became %lx\n", val);
416 /****************************************************************************/
418 static int load_flat_file(struct linux_binprm *bprm,
419 struct lib_info *libinfo, int id, unsigned long *extra_stack)
421 struct flat_hdr *hdr;
422 unsigned long textpos, datapos, realdatastart;
423 unsigned long text_len, data_len, bss_len, stack_len, full_data, flags;
424 unsigned long len, memp, memp_size, extra, rlim;
425 unsigned long __user *reloc, *rp;
429 unsigned long start_code, end_code;
433 hdr = ((struct flat_hdr *) bprm->buf); /* exec-header */
434 inode = file_inode(bprm->file);
436 text_len = ntohl(hdr->data_start);
437 data_len = ntohl(hdr->data_end) - ntohl(hdr->data_start);
438 bss_len = ntohl(hdr->bss_end) - ntohl(hdr->data_end);
439 stack_len = ntohl(hdr->stack_size);
441 stack_len += *extra_stack;
442 *extra_stack = stack_len;
444 relocs = ntohl(hdr->reloc_count);
445 flags = ntohl(hdr->flags);
446 rev = ntohl(hdr->rev);
447 full_data = data_len + relocs * sizeof(unsigned long);
449 if (strncmp(hdr->magic, "bFLT", 4)) {
451 * Previously, here was a printk to tell people
452 * "BINFMT_FLAT: bad header magic".
453 * But for the kernel which also use ELF FD-PIC format, this
454 * error message is confusing.
455 * because a lot of people do not manage to produce good
461 if (flags & FLAT_FLAG_KTRACE)
462 pr_info("Loading file: %s\n", bprm->filename);
464 if (rev != FLAT_VERSION && rev != OLD_FLAT_VERSION) {
465 pr_err("bad flat file version 0x%x (supported 0x%lx and 0x%lx)\n",
466 rev, FLAT_VERSION, OLD_FLAT_VERSION);
471 /* Don't allow old format executables to use shared libraries */
472 if (rev == OLD_FLAT_VERSION && id != 0) {
473 pr_err("shared libraries are not available before rev 0x%lx\n",
480 * Make sure the header params are sane.
481 * 28 bits (256 MB) is way more than reasonable in this case.
482 * If some top bits are set we have probable binary corruption.
484 if ((text_len | data_len | bss_len | stack_len | full_data) >> 28) {
485 pr_err("bad header\n");
491 * fix up the flags for the older format, there were all kinds
492 * of endian hacks, this only works for the simple cases
494 if (rev == OLD_FLAT_VERSION && flat_old_ram_flag(flags))
495 flags = FLAT_FLAG_RAM;
497 #ifndef CONFIG_BINFMT_ZFLAT
498 if (flags & (FLAT_FLAG_GZIP|FLAT_FLAG_GZDATA)) {
499 pr_err("Support for ZFLAT executables is not enabled.\n");
506 * Check initial limits. This avoids letting people circumvent
507 * size limits imposed on them by creating programs with large
508 * arrays in the data or bss.
510 rlim = rlimit(RLIMIT_DATA);
511 if (rlim >= RLIM_INFINITY)
513 if (data_len + bss_len > rlim) {
518 /* Flush all traces of the currently running executable */
520 ret = flush_old_exec(bprm);
524 /* OK, This is the point of no return */
525 set_personality(PER_LINUX_32BIT);
526 setup_new_exec(bprm);
530 * calculate the extra space we need to map in
532 extra = max_t(unsigned long, bss_len + stack_len,
533 relocs * sizeof(unsigned long));
536 * there are a couple of cases here, the separate code/data
537 * case, and then the fully copied to RAM case which lumps
540 if (!IS_ENABLED(CONFIG_MMU) && !(flags & (FLAT_FLAG_RAM|FLAT_FLAG_GZIP))) {
542 * this should give us a ROM ptr, but if it doesn't we don't
545 pr_debug("ROM mapping of file (we hope)\n");
547 textpos = vm_mmap(bprm->file, 0, text_len, PROT_READ|PROT_EXEC,
548 MAP_PRIVATE|MAP_EXECUTABLE, 0);
549 if (!textpos || IS_ERR_VALUE(textpos)) {
553 pr_err("Unable to mmap process text, errno %d\n", ret);
557 len = data_len + extra + MAX_SHARED_LIBS * sizeof(unsigned long);
558 len = PAGE_ALIGN(len);
559 realdatastart = vm_mmap(NULL, 0, len,
560 PROT_READ|PROT_WRITE|PROT_EXEC, MAP_PRIVATE, 0);
562 if (realdatastart == 0 || IS_ERR_VALUE(realdatastart)) {
566 pr_err("Unable to allocate RAM for process data, "
568 vm_munmap(textpos, text_len);
571 datapos = ALIGN(realdatastart +
572 MAX_SHARED_LIBS * sizeof(unsigned long),
575 pr_debug("Allocated data+bss+stack (%ld bytes): %lx\n",
576 data_len + bss_len + stack_len, datapos);
578 fpos = ntohl(hdr->data_start);
579 #ifdef CONFIG_BINFMT_ZFLAT
580 if (flags & FLAT_FLAG_GZDATA) {
581 result = decompress_exec(bprm, fpos, (char *)datapos,
586 result = read_code(bprm->file, datapos, fpos,
589 if (IS_ERR_VALUE(result)) {
591 pr_err("Unable to read data+bss, errno %d\n", ret);
592 vm_munmap(textpos, text_len);
593 vm_munmap(realdatastart, len);
597 reloc = (unsigned long __user *)
598 (datapos + (ntohl(hdr->reloc_start) - text_len));
599 memp = realdatastart;
603 len = text_len + data_len + extra + MAX_SHARED_LIBS * sizeof(unsigned long);
604 len = PAGE_ALIGN(len);
605 textpos = vm_mmap(NULL, 0, len,
606 PROT_READ | PROT_EXEC | PROT_WRITE, MAP_PRIVATE, 0);
608 if (!textpos || IS_ERR_VALUE(textpos)) {
612 pr_err("Unable to allocate RAM for process text/data, "
617 realdatastart = textpos + ntohl(hdr->data_start);
618 datapos = ALIGN(realdatastart +
619 MAX_SHARED_LIBS * sizeof(unsigned long),
622 reloc = (unsigned long __user *)
623 (datapos + (ntohl(hdr->reloc_start) - text_len));
626 #ifdef CONFIG_BINFMT_ZFLAT
628 * load it all in and treat it like a RAM load from now on
630 if (flags & FLAT_FLAG_GZIP) {
631 result = decompress_exec(bprm, sizeof(struct flat_hdr),
632 (((char *)textpos) + sizeof(struct flat_hdr)),
633 (text_len + full_data
634 - sizeof(struct flat_hdr)),
636 memmove((void *) datapos, (void *) realdatastart,
638 } else if (flags & FLAT_FLAG_GZDATA) {
639 result = read_code(bprm->file, textpos, 0, text_len);
640 if (!IS_ERR_VALUE(result))
641 result = decompress_exec(bprm, text_len, (char *) datapos,
646 result = read_code(bprm->file, textpos, 0, text_len);
647 if (!IS_ERR_VALUE(result))
648 result = read_code(bprm->file, datapos,
649 ntohl(hdr->data_start),
652 if (IS_ERR_VALUE(result)) {
654 pr_err("Unable to read code+data+bss, errno %d\n", ret);
655 vm_munmap(textpos, text_len + data_len + extra +
656 MAX_SHARED_LIBS * sizeof(unsigned long));
661 start_code = textpos + sizeof(struct flat_hdr);
662 end_code = textpos + text_len;
663 text_len -= sizeof(struct flat_hdr); /* the real code len */
665 /* The main program needs a little extra setup in the task structure */
667 current->mm->start_code = start_code;
668 current->mm->end_code = end_code;
669 current->mm->start_data = datapos;
670 current->mm->end_data = datapos + data_len;
672 * set up the brk stuff, uses any slack left in data/bss/stack
673 * allocation. We put the brk after the bss (between the bss
674 * and stack) like other platforms.
675 * Userspace code relies on the stack pointer starting out at
676 * an address right at the end of a page.
678 current->mm->start_brk = datapos + data_len + bss_len;
679 current->mm->brk = (current->mm->start_brk + 3) & ~3;
681 current->mm->context.end_brk = memp + memp_size - stack_len;
685 if (flags & FLAT_FLAG_KTRACE) {
686 pr_info("Mapping is %lx, Entry point is %x, data_start is %x\n",
687 textpos, 0x00ffffff&ntohl(hdr->entry), ntohl(hdr->data_start));
688 pr_info("%s %s: TEXT=%lx-%lx DATA=%lx-%lx BSS=%lx-%lx\n",
689 id ? "Lib" : "Load", bprm->filename,
690 start_code, end_code, datapos, datapos + data_len,
691 datapos + data_len, (datapos + data_len + bss_len + 3) & ~3);
694 /* Store the current module values into the global library structure */
695 libinfo->lib_list[id].start_code = start_code;
696 libinfo->lib_list[id].start_data = datapos;
697 libinfo->lib_list[id].start_brk = datapos + data_len + bss_len;
698 libinfo->lib_list[id].text_len = text_len;
699 libinfo->lib_list[id].loaded = 1;
700 libinfo->lib_list[id].entry = (0x00ffffff & ntohl(hdr->entry)) + textpos;
701 libinfo->lib_list[id].build_date = ntohl(hdr->build_date);
704 * We just load the allocations into some temporary memory to
705 * help simplify all this mumbo jumbo
707 * We've got two different sections of relocation entries.
708 * The first is the GOT which resides at the beginning of the data segment
709 * and is terminated with a -1. This one can be relocated in place.
710 * The second is the extra relocation entries tacked after the image's
711 * data segment. These require a little more processing as the entry is
712 * really an offset into the image which contains an offset into the
715 if (flags & FLAT_FLAG_GOTPIC) {
716 for (rp = (unsigned long __user *)datapos; ; rp++) {
717 unsigned long addr, rp_val;
718 if (get_user(rp_val, rp))
720 if (rp_val == 0xffffffff)
723 addr = calc_reloc(rp_val, libinfo, id, 0);
724 if (addr == RELOC_FAILED) {
728 if (put_user(addr, rp))
735 * Now run through the relocation entries.
736 * We've got to be careful here as C++ produces relocatable zero
737 * entries in the constructor and destructor tables which are then
738 * tested for being not zero (which will always occur unless we're
739 * based from address zero). This causes an endless loop as __start
740 * is at zero. The solution used is to not relocate zero addresses.
741 * This has the negative side effect of not allowing a global data
742 * reference to be statically initialised to _stext (I've moved
743 * __start to address 4 so that is okay).
745 if (rev > OLD_FLAT_VERSION) {
746 unsigned long __maybe_unused persistent = 0;
747 for (i = 0; i < relocs; i++) {
748 unsigned long addr, relval;
751 * Get the address of the pointer to be
752 * relocated (of course, the address has to be
755 if (get_user(relval, reloc + i))
757 relval = ntohl(relval);
758 if (flat_set_persistent(relval, &persistent))
760 addr = flat_get_relocate_addr(relval);
761 rp = (unsigned long __user *)calc_reloc(addr, libinfo, id, 1);
762 if (rp == (unsigned long __user *)RELOC_FAILED) {
767 /* Get the pointer's value. */
768 addr = flat_get_addr_from_rp(rp, relval, flags,
772 * Do the relocation. PIC relocs in the data section are
773 * already in target order
775 if ((flags & FLAT_FLAG_GOTPIC) == 0)
777 addr = calc_reloc(addr, libinfo, id, 0);
778 if (addr == RELOC_FAILED) {
783 /* Write back the relocated pointer. */
784 flat_put_addr_at_rp(rp, addr, relval);
788 for (i = 0; i < relocs; i++) {
789 unsigned long relval;
790 if (get_user(relval, reloc + i))
792 relval = ntohl(relval);
797 flush_icache_range(start_code, end_code);
799 /* zero the BSS, BRK and stack areas */
800 if (clear_user((void __user *)(datapos + data_len), bss_len +
801 (memp + memp_size - stack_len - /* end brk */
802 libinfo->lib_list[id].start_brk) + /* start brk */
812 /****************************************************************************/
813 #ifdef CONFIG_BINFMT_SHARED_FLAT
816 * Load a shared library into memory. The library gets its own data
817 * segment (including bss) but not argv/argc/environ.
820 static int load_flat_shared_library(int id, struct lib_info *libs)
822 struct linux_binprm bprm;
826 memset(&bprm, 0, sizeof(bprm));
828 /* Create the file name */
829 sprintf(buf, "/lib/lib%d.so", id);
831 /* Open the file up */
833 bprm.file = open_exec(bprm.filename);
834 res = PTR_ERR(bprm.file);
835 if (IS_ERR(bprm.file))
838 bprm.cred = prepare_exec_creds();
843 /* We don't really care about recalculating credentials at this point
844 * as we're past the point of no return and are dealing with shared
847 bprm.cred_prepared = 1;
849 res = prepare_binprm(&bprm);
852 res = load_flat_file(&bprm, libs, id, NULL);
854 abort_creds(bprm.cred);
857 allow_write_access(bprm.file);
863 #endif /* CONFIG_BINFMT_SHARED_FLAT */
864 /****************************************************************************/
867 * These are the functions used to load flat style executables and shared
868 * libraries. There is no binary dependent code anywhere else.
871 static int load_flat_binary(struct linux_binprm *bprm)
873 struct lib_info libinfo;
874 struct pt_regs *regs = current_pt_regs();
875 unsigned long stack_len = 0;
876 unsigned long start_addr;
880 memset(&libinfo, 0, sizeof(libinfo));
883 * We have to add the size of our arguments to our stack size
884 * otherwise it's too easy for users to create stack overflows
885 * by passing in a huge argument list. And yes, we have to be
886 * pedantic and include space for the argv/envp array as it may have
890 stack_len += PAGE_SIZE * MAX_ARG_PAGES - bprm->p; /* the strings */
892 stack_len += (bprm->argc + 1) * sizeof(char *); /* the argv array */
893 stack_len += (bprm->envc + 1) * sizeof(char *); /* the envp array */
894 stack_len = ALIGN(stack_len, FLAT_STACK_ALIGN);
896 res = load_flat_file(bprm, &libinfo, 0, &stack_len);
900 /* Update data segment pointers for all libraries */
901 for (i = 0; i < MAX_SHARED_LIBS; i++) {
902 if (!libinfo.lib_list[i].loaded)
904 for (j = 0; j < MAX_SHARED_LIBS; j++) {
905 unsigned long val = libinfo.lib_list[j].loaded ?
906 libinfo.lib_list[j].start_data : UNLOADED_LIB;
907 unsigned long __user *p = (unsigned long __user *)
908 libinfo.lib_list[i].start_data;
910 if (put_user(val, p))
915 install_exec_creds(bprm);
917 set_binfmt(&flat_format);
920 res = setup_arg_pages(bprm, STACK_TOP, EXSTACK_DEFAULT);
922 res = create_flat_tables(bprm, bprm->p);
924 /* Stash our initial stack pointer into the mm structure */
925 current->mm->start_stack =
926 ((current->mm->context.end_brk + stack_len + 3) & ~3) - 4;
927 pr_debug("sp=%lx\n", current->mm->start_stack);
929 /* copy the arg pages onto the stack */
930 res = transfer_args_to_stack(bprm, ¤t->mm->start_stack);
932 res = create_flat_tables(bprm, current->mm->start_stack);
937 /* Fake some return addresses to ensure the call chain will
938 * initialise library in order for us. We are required to call
939 * lib 1 first, then 2, ... and finally the main program (id 0).
941 start_addr = libinfo.lib_list[0].entry;
943 #ifdef CONFIG_BINFMT_SHARED_FLAT
944 for (i = MAX_SHARED_LIBS-1; i > 0; i--) {
945 if (libinfo.lib_list[i].loaded) {
946 /* Push previos first to call address */
947 unsigned long __user *sp;
948 current->mm->start_stack -= sizeof(unsigned long);
949 sp = (unsigned long __user *)current->mm->start_stack;
950 __put_user(start_addr, sp);
951 start_addr = libinfo.lib_list[i].entry;
956 #ifdef FLAT_PLAT_INIT
957 FLAT_PLAT_INIT(regs);
960 pr_debug("start_thread(regs=0x%p, entry=0x%lx, start_stack=0x%lx)\n",
961 regs, start_addr, current->mm->start_stack);
962 start_thread(regs, start_addr, current->mm->start_stack);
967 /****************************************************************************/
969 static int __init init_flat_binfmt(void)
971 register_binfmt(&flat_format);
974 core_initcall(init_flat_binfmt);
976 /****************************************************************************/