1 // SPDX-License-Identifier: GPL-2.0
2 /****************************************************************************/
4 * linux/fs/binfmt_flat.c
6 * Copyright (C) 2000-2003 David McCullough <davidm@snapgear.com>
7 * Copyright (C) 2002 Greg Ungerer <gerg@snapgear.com>
8 * Copyright (C) 2002 SnapGear, by Paul Dale <pauli@snapgear.com>
9 * Copyright (C) 2000, 2001 Lineo, by David McCullough <davidm@lineo.com>
12 * linux/fs/binfmt_aout.c:
13 * Copyright (C) 1991, 1992, 1996 Linus Torvalds
14 * linux/fs/binfmt_flat.c for 2.0 kernel
15 * Copyright (C) 1998 Kenneth Albanowski <kjahds@kjahds.com>
16 * JAN/99 -- coded full program relocation (gerg@snapgear.com)
19 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
21 #include <linux/kernel.h>
22 #include <linux/sched.h>
23 #include <linux/sched/task_stack.h>
25 #include <linux/mman.h>
26 #include <linux/errno.h>
27 #include <linux/signal.h>
28 #include <linux/string.h>
30 #include <linux/file.h>
31 #include <linux/ptrace.h>
32 #include <linux/user.h>
33 #include <linux/slab.h>
34 #include <linux/binfmts.h>
35 #include <linux/personality.h>
36 #include <linux/init.h>
37 #include <linux/flat.h>
38 #include <linux/uaccess.h>
39 #include <linux/vmalloc.h>
41 #include <asm/byteorder.h>
42 #include <asm/unaligned.h>
43 #include <asm/cacheflush.h>
47 #ifndef flat_get_relocate_addr
48 #define flat_get_relocate_addr(rel) (rel)
51 /****************************************************************************/
54 * User data (data section and bss) needs to be aligned.
55 * We pick 0x20 here because it is the max value elf2flt has always
56 * used in producing FLAT files, and because it seems to be large
57 * enough to make all the gcc alignment related tests happy.
59 #define FLAT_DATA_ALIGN (0x20)
62 * User data (stack) also needs to be aligned.
63 * Here we can be a bit looser than the data sections since this
64 * needs to only meet arch ABI requirements.
66 #define FLAT_STACK_ALIGN max_t(unsigned long, sizeof(void *), ARCH_SLAB_MINALIGN)
68 #define RELOC_FAILED 0xff00ff01 /* Relocation incorrect somewhere */
69 #define UNLOADED_LIB 0x7ff000ff /* Placeholder for unused library */
71 #define MAX_SHARED_LIBS (1)
73 #ifdef CONFIG_BINFMT_FLAT_NO_DATA_START_OFFSET
74 #define DATA_START_OFFSET_WORDS (0)
76 #define DATA_START_OFFSET_WORDS (MAX_SHARED_LIBS)
81 unsigned long start_code; /* Start of text segment */
82 unsigned long start_data; /* Start of data segment */
83 unsigned long start_brk; /* End of data segment */
84 unsigned long text_len; /* Length of text segment */
85 unsigned long entry; /* Start address for this module */
86 unsigned long build_date; /* When this one was compiled */
87 bool loaded; /* Has this library been loaded? */
88 } lib_list[MAX_SHARED_LIBS];
91 static int load_flat_binary(struct linux_binprm *);
93 static struct linux_binfmt flat_format = {
94 .module = THIS_MODULE,
95 .load_binary = load_flat_binary,
99 /****************************************************************************/
101 * create_flat_tables() parses the env- and arg-strings in new user
102 * memory and creates the pointer tables from them, and puts their
103 * addresses on the "stack", recording the new stack pointer value.
106 static int create_flat_tables(struct linux_binprm *bprm, unsigned long arg_start)
109 unsigned long __user *sp;
112 p = (char __user *)arg_start;
113 sp = (unsigned long __user *)current->mm->start_stack;
115 sp -= bprm->envc + 1;
116 sp -= bprm->argc + 1;
117 if (IS_ENABLED(CONFIG_BINFMT_FLAT_ARGVP_ENVP_ON_STACK))
118 sp -= 2; /* argvp + envp */
121 current->mm->start_stack = (unsigned long)sp & -FLAT_STACK_ALIGN;
122 sp = (unsigned long __user *)current->mm->start_stack;
124 if (put_user(bprm->argc, sp++))
126 if (IS_ENABLED(CONFIG_BINFMT_FLAT_ARGVP_ENVP_ON_STACK)) {
127 unsigned long argv, envp;
128 argv = (unsigned long)(sp + 2);
129 envp = (unsigned long)(sp + 2 + bprm->argc + 1);
130 if (put_user(argv, sp++) || put_user(envp, sp++))
134 current->mm->arg_start = (unsigned long)p;
135 for (i = bprm->argc; i > 0; i--) {
136 if (put_user((unsigned long)p, sp++))
138 len = strnlen_user(p, MAX_ARG_STRLEN);
139 if (!len || len > MAX_ARG_STRLEN)
143 if (put_user(0, sp++))
145 current->mm->arg_end = (unsigned long)p;
147 current->mm->env_start = (unsigned long) p;
148 for (i = bprm->envc; i > 0; i--) {
149 if (put_user((unsigned long)p, sp++))
151 len = strnlen_user(p, MAX_ARG_STRLEN);
152 if (!len || len > MAX_ARG_STRLEN)
156 if (put_user(0, sp++))
158 current->mm->env_end = (unsigned long)p;
163 /****************************************************************************/
165 #ifdef CONFIG_BINFMT_ZFLAT
167 #include <linux/zlib.h>
169 #define LBUFSIZE 4000
172 #define ASCII_FLAG 0x01 /* bit 0 set: file probably ASCII text */
173 #define CONTINUATION 0x02 /* bit 1 set: continuation of multi-part gzip file */
174 #define EXTRA_FIELD 0x04 /* bit 2 set: extra field present */
175 #define ORIG_NAME 0x08 /* bit 3 set: original file name present */
176 #define COMMENT 0x10 /* bit 4 set: file comment present */
177 #define ENCRYPTED 0x20 /* bit 5 set: file is encrypted */
178 #define RESERVED 0xC0 /* bit 6,7: reserved */
180 static int decompress_exec(struct linux_binprm *bprm, loff_t fpos, char *dst,
187 pr_debug("decompress_exec(offset=%llx,buf=%p,len=%lx)\n", fpos, dst, len);
189 memset(&strm, 0, sizeof(strm));
190 strm.workspace = kmalloc(zlib_inflate_workspacesize(), GFP_KERNEL);
194 buf = kmalloc(LBUFSIZE, GFP_KERNEL);
200 /* Read in first chunk of data and parse gzip header. */
201 ret = kernel_read(bprm->file, buf, LBUFSIZE, &fpos);
209 /* Check minimum size -- gzip header */
211 pr_debug("file too small?\n");
215 /* Check gzip magic number */
216 if ((buf[0] != 037) || ((buf[1] != 0213) && (buf[1] != 0236))) {
217 pr_debug("unknown compression magic?\n");
221 /* Check gzip method */
223 pr_debug("unknown compression method?\n");
226 /* Check gzip flags */
227 if ((buf[3] & ENCRYPTED) || (buf[3] & CONTINUATION) ||
228 (buf[3] & RESERVED)) {
229 pr_debug("unknown flags?\n");
234 if (buf[3] & EXTRA_FIELD) {
235 ret += 2 + buf[10] + (buf[11] << 8);
236 if (unlikely(ret >= LBUFSIZE)) {
237 pr_debug("buffer overflow (EXTRA)?\n");
241 if (buf[3] & ORIG_NAME) {
242 while (ret < LBUFSIZE && buf[ret++] != 0)
244 if (unlikely(ret == LBUFSIZE)) {
245 pr_debug("buffer overflow (ORIG_NAME)?\n");
249 if (buf[3] & COMMENT) {
250 while (ret < LBUFSIZE && buf[ret++] != 0)
252 if (unlikely(ret == LBUFSIZE)) {
253 pr_debug("buffer overflow (COMMENT)?\n");
259 strm.avail_in -= ret;
262 strm.avail_out = len;
265 if (zlib_inflateInit2(&strm, -MAX_WBITS) != Z_OK) {
266 pr_debug("zlib init failed?\n");
270 while ((ret = zlib_inflate(&strm, Z_NO_FLUSH)) == Z_OK) {
271 ret = kernel_read(bprm->file, buf, LBUFSIZE, &fpos);
282 pr_debug("decompression failed (%d), %s\n",
289 zlib_inflateEnd(&strm);
293 kfree(strm.workspace);
297 #endif /* CONFIG_BINFMT_ZFLAT */
299 /****************************************************************************/
302 calc_reloc(unsigned long r, struct lib_info *p)
305 unsigned long start_brk;
306 unsigned long start_data;
307 unsigned long text_len;
308 unsigned long start_code;
310 start_brk = p->lib_list[0].start_brk;
311 start_data = p->lib_list[0].start_data;
312 start_code = p->lib_list[0].start_code;
313 text_len = p->lib_list[0].text_len;
315 if (r > start_brk - start_data + text_len) {
316 pr_err("reloc outside program 0x%lx (0 - 0x%lx/0x%lx)",
317 r, start_brk-start_data+text_len, text_len);
321 if (r < text_len) /* In text segment */
322 addr = r + start_code;
323 else /* In data segment */
324 addr = r - text_len + start_data;
326 /* Range checked already above so doing the range tests is redundant...*/
330 pr_cont(", killing %s!\n", current->comm);
331 send_sig(SIGSEGV, current, 0);
336 /****************************************************************************/
338 #ifdef CONFIG_BINFMT_FLAT_OLD
339 static void old_reloc(unsigned long rl)
341 static const char *segment[] = { "TEXT", "DATA", "BSS", "*UNKNOWN*" };
343 unsigned long __user *ptr;
347 #if defined(CONFIG_COLDFIRE)
348 ptr = (unsigned long __user *)(current->mm->start_code + r.reloc.offset);
350 ptr = (unsigned long __user *)(current->mm->start_data + r.reloc.offset);
354 pr_debug("Relocation of variable at DATASEG+%x "
355 "(address %p, currently %lx) into segment %s\n",
356 r.reloc.offset, ptr, val, segment[r.reloc.type]);
358 switch (r.reloc.type) {
359 case OLD_FLAT_RELOC_TYPE_TEXT:
360 val += current->mm->start_code;
362 case OLD_FLAT_RELOC_TYPE_DATA:
363 val += current->mm->start_data;
365 case OLD_FLAT_RELOC_TYPE_BSS:
366 val += current->mm->end_data;
369 pr_err("Unknown relocation type=%x\n", r.reloc.type);
374 pr_debug("Relocation became %lx\n", val);
376 #endif /* CONFIG_BINFMT_FLAT_OLD */
378 /****************************************************************************/
380 static inline u32 __user *skip_got_header(u32 __user *rp)
382 if (IS_ENABLED(CONFIG_RISCV)) {
384 * RISC-V has a 16 byte GOT PLT header for elf64-riscv
385 * and 8 byte GOT PLT header for elf32-riscv.
386 * Skip the whole GOT PLT header, since it is reserved
387 * for the dynamic linker (ld.so).
389 u32 rp_val0, rp_val1;
391 if (get_user(rp_val0, rp))
393 if (get_user(rp_val1, rp + 1))
396 if (rp_val0 == 0xffffffff && rp_val1 == 0xffffffff)
398 else if (rp_val0 == 0xffffffff)
404 static int load_flat_file(struct linux_binprm *bprm,
405 struct lib_info *libinfo, unsigned long *extra_stack)
407 struct flat_hdr *hdr;
408 unsigned long textpos, datapos, realdatastart;
409 u32 text_len, data_len, bss_len, stack_len, full_data, flags;
410 unsigned long len, memp, memp_size, extra, rlim;
411 __be32 __user *reloc;
415 unsigned long start_code, end_code;
419 hdr = ((struct flat_hdr *) bprm->buf); /* exec-header */
421 text_len = ntohl(hdr->data_start);
422 data_len = ntohl(hdr->data_end) - ntohl(hdr->data_start);
423 bss_len = ntohl(hdr->bss_end) - ntohl(hdr->data_end);
424 stack_len = ntohl(hdr->stack_size);
426 stack_len += *extra_stack;
427 *extra_stack = stack_len;
429 relocs = ntohl(hdr->reloc_count);
430 flags = ntohl(hdr->flags);
431 rev = ntohl(hdr->rev);
432 full_data = data_len + relocs * sizeof(unsigned long);
434 if (strncmp(hdr->magic, "bFLT", 4)) {
436 * Previously, here was a printk to tell people
437 * "BINFMT_FLAT: bad header magic".
438 * But for the kernel which also use ELF FD-PIC format, this
439 * error message is confusing.
440 * because a lot of people do not manage to produce good
446 if (flags & FLAT_FLAG_KTRACE)
447 pr_info("Loading file: %s\n", bprm->filename);
449 #ifdef CONFIG_BINFMT_FLAT_OLD
450 if (rev != FLAT_VERSION && rev != OLD_FLAT_VERSION) {
451 pr_err("bad flat file version 0x%x (supported 0x%lx and 0x%lx)\n",
452 rev, FLAT_VERSION, OLD_FLAT_VERSION);
458 * fix up the flags for the older format, there were all kinds
459 * of endian hacks, this only works for the simple cases
461 if (rev == OLD_FLAT_VERSION &&
462 (flags || IS_ENABLED(CONFIG_BINFMT_FLAT_OLD_ALWAYS_RAM)))
463 flags = FLAT_FLAG_RAM;
465 #else /* CONFIG_BINFMT_FLAT_OLD */
466 if (rev != FLAT_VERSION) {
467 pr_err("bad flat file version 0x%x (supported 0x%lx)\n",
472 #endif /* !CONFIG_BINFMT_FLAT_OLD */
475 * Make sure the header params are sane.
476 * 28 bits (256 MB) is way more than reasonable in this case.
477 * If some top bits are set we have probable binary corruption.
479 if ((text_len | data_len | bss_len | stack_len | full_data) >> 28) {
480 pr_err("bad header\n");
485 #ifndef CONFIG_BINFMT_ZFLAT
486 if (flags & (FLAT_FLAG_GZIP|FLAT_FLAG_GZDATA)) {
487 pr_err("Support for ZFLAT executables is not enabled.\n");
494 * Check initial limits. This avoids letting people circumvent
495 * size limits imposed on them by creating programs with large
496 * arrays in the data or bss.
498 rlim = rlimit(RLIMIT_DATA);
499 if (rlim >= RLIM_INFINITY)
501 if (data_len + bss_len > rlim) {
506 /* Flush all traces of the currently running executable */
507 ret = begin_new_exec(bprm);
511 /* OK, This is the point of no return */
512 set_personality(PER_LINUX_32BIT);
513 setup_new_exec(bprm);
516 * calculate the extra space we need to map in
518 extra = max_t(unsigned long, bss_len + stack_len,
519 relocs * sizeof(unsigned long));
522 * there are a couple of cases here, the separate code/data
523 * case, and then the fully copied to RAM case which lumps
526 if (!IS_ENABLED(CONFIG_MMU) && !(flags & (FLAT_FLAG_RAM|FLAT_FLAG_GZIP))) {
528 * this should give us a ROM ptr, but if it doesn't we don't
531 pr_debug("ROM mapping of file (we hope)\n");
533 textpos = vm_mmap(bprm->file, 0, text_len, PROT_READ|PROT_EXEC,
535 if (!textpos || IS_ERR_VALUE(textpos)) {
539 pr_err("Unable to mmap process text, errno %d\n", ret);
543 len = data_len + extra +
544 DATA_START_OFFSET_WORDS * sizeof(unsigned long);
545 len = PAGE_ALIGN(len);
546 realdatastart = vm_mmap(NULL, 0, len,
547 PROT_READ|PROT_WRITE|PROT_EXEC, MAP_PRIVATE, 0);
549 if (realdatastart == 0 || IS_ERR_VALUE(realdatastart)) {
553 pr_err("Unable to allocate RAM for process data, "
555 vm_munmap(textpos, text_len);
558 datapos = ALIGN(realdatastart +
559 DATA_START_OFFSET_WORDS * sizeof(unsigned long),
562 pr_debug("Allocated data+bss+stack (%u bytes): %lx\n",
563 data_len + bss_len + stack_len, datapos);
565 fpos = ntohl(hdr->data_start);
566 #ifdef CONFIG_BINFMT_ZFLAT
567 if (flags & FLAT_FLAG_GZDATA) {
568 result = decompress_exec(bprm, fpos, (char *)datapos,
573 result = read_code(bprm->file, datapos, fpos,
576 if (IS_ERR_VALUE(result)) {
578 pr_err("Unable to read data+bss, errno %d\n", ret);
579 vm_munmap(textpos, text_len);
580 vm_munmap(realdatastart, len);
584 reloc = (__be32 __user *)
585 (datapos + (ntohl(hdr->reloc_start) - text_len));
586 memp = realdatastart;
590 len = text_len + data_len + extra +
591 DATA_START_OFFSET_WORDS * sizeof(u32);
592 len = PAGE_ALIGN(len);
593 textpos = vm_mmap(NULL, 0, len,
594 PROT_READ | PROT_EXEC | PROT_WRITE, MAP_PRIVATE, 0);
596 if (!textpos || IS_ERR_VALUE(textpos)) {
600 pr_err("Unable to allocate RAM for process text/data, "
605 realdatastart = textpos + ntohl(hdr->data_start);
606 datapos = ALIGN(realdatastart +
607 DATA_START_OFFSET_WORDS * sizeof(u32),
610 reloc = (__be32 __user *)
611 (datapos + (ntohl(hdr->reloc_start) - text_len));
614 #ifdef CONFIG_BINFMT_ZFLAT
616 * load it all in and treat it like a RAM load from now on
618 if (flags & FLAT_FLAG_GZIP) {
620 result = decompress_exec(bprm, sizeof(struct flat_hdr),
621 (((char *)textpos) + sizeof(struct flat_hdr)),
622 (text_len + full_data
623 - sizeof(struct flat_hdr)),
625 memmove((void *) datapos, (void *) realdatastart,
629 * This is used on MMU systems mainly for testing.
630 * Let's use a kernel buffer to simplify things.
632 long unz_text_len = text_len - sizeof(struct flat_hdr);
633 long unz_len = unz_text_len + full_data;
634 char *unz_data = vmalloc(unz_len);
638 result = decompress_exec(bprm, sizeof(struct flat_hdr),
639 unz_data, unz_len, 0);
641 (copy_to_user((void __user *)textpos + sizeof(struct flat_hdr),
642 unz_data, unz_text_len) ||
643 copy_to_user((void __user *)datapos,
644 unz_data + unz_text_len, full_data)))
649 } else if (flags & FLAT_FLAG_GZDATA) {
650 result = read_code(bprm->file, textpos, 0, text_len);
651 if (!IS_ERR_VALUE(result)) {
653 result = decompress_exec(bprm, text_len, (char *) datapos,
656 char *unz_data = vmalloc(full_data);
660 result = decompress_exec(bprm, text_len,
661 unz_data, full_data, 0);
663 copy_to_user((void __user *)datapos,
664 unz_data, full_data))
671 #endif /* CONFIG_BINFMT_ZFLAT */
673 result = read_code(bprm->file, textpos, 0, text_len);
674 if (!IS_ERR_VALUE(result))
675 result = read_code(bprm->file, datapos,
676 ntohl(hdr->data_start),
679 if (IS_ERR_VALUE(result)) {
681 pr_err("Unable to read code+data+bss, errno %d\n", ret);
682 vm_munmap(textpos, text_len + data_len + extra +
683 DATA_START_OFFSET_WORDS * sizeof(u32));
688 start_code = textpos + sizeof(struct flat_hdr);
689 end_code = textpos + text_len;
690 text_len -= sizeof(struct flat_hdr); /* the real code len */
692 /* The main program needs a little extra setup in the task structure */
693 current->mm->start_code = start_code;
694 current->mm->end_code = end_code;
695 current->mm->start_data = datapos;
696 current->mm->end_data = datapos + data_len;
698 * set up the brk stuff, uses any slack left in data/bss/stack
699 * allocation. We put the brk after the bss (between the bss
700 * and stack) like other platforms.
701 * Userspace code relies on the stack pointer starting out at
702 * an address right at the end of a page.
704 current->mm->start_brk = datapos + data_len + bss_len;
705 current->mm->brk = (current->mm->start_brk + 3) & ~3;
707 current->mm->context.end_brk = memp + memp_size - stack_len;
710 if (flags & FLAT_FLAG_KTRACE) {
711 pr_info("Mapping is %lx, Entry point is %x, data_start is %x\n",
712 textpos, 0x00ffffff&ntohl(hdr->entry), ntohl(hdr->data_start));
713 pr_info("%s %s: TEXT=%lx-%lx DATA=%lx-%lx BSS=%lx-%lx\n",
714 "Load", bprm->filename,
715 start_code, end_code, datapos, datapos + data_len,
716 datapos + data_len, (datapos + data_len + bss_len + 3) & ~3);
719 /* Store the current module values into the global library structure */
720 libinfo->lib_list[0].start_code = start_code;
721 libinfo->lib_list[0].start_data = datapos;
722 libinfo->lib_list[0].start_brk = datapos + data_len + bss_len;
723 libinfo->lib_list[0].text_len = text_len;
724 libinfo->lib_list[0].loaded = 1;
725 libinfo->lib_list[0].entry = (0x00ffffff & ntohl(hdr->entry)) + textpos;
726 libinfo->lib_list[0].build_date = ntohl(hdr->build_date);
729 * We just load the allocations into some temporary memory to
730 * help simplify all this mumbo jumbo
732 * We've got two different sections of relocation entries.
733 * The first is the GOT which resides at the beginning of the data segment
734 * and is terminated with a -1. This one can be relocated in place.
735 * The second is the extra relocation entries tacked after the image's
736 * data segment. These require a little more processing as the entry is
737 * really an offset into the image which contains an offset into the
740 if (flags & FLAT_FLAG_GOTPIC) {
741 rp = skip_got_header((u32 __user *) datapos);
744 if (get_user(rp_val, rp))
746 if (rp_val == 0xffffffff)
749 addr = calc_reloc(rp_val, libinfo);
750 if (addr == RELOC_FAILED) {
754 if (put_user(addr, rp))
761 * Now run through the relocation entries.
762 * We've got to be careful here as C++ produces relocatable zero
763 * entries in the constructor and destructor tables which are then
764 * tested for being not zero (which will always occur unless we're
765 * based from address zero). This causes an endless loop as __start
766 * is at zero. The solution used is to not relocate zero addresses.
767 * This has the negative side effect of not allowing a global data
768 * reference to be statically initialised to _stext (I've moved
769 * __start to address 4 so that is okay).
771 if (rev > OLD_FLAT_VERSION) {
772 for (i = 0; i < relocs; i++) {
777 * Get the address of the pointer to be
778 * relocated (of course, the address has to be
781 if (get_user(tmp, reloc + i))
784 addr = flat_get_relocate_addr(relval);
785 rp = (u32 __user *)calc_reloc(addr, libinfo);
786 if (rp == (u32 __user *)RELOC_FAILED) {
791 /* Get the pointer's value. */
792 ret = flat_get_addr_from_rp(rp, relval, flags, &addr);
798 * Do the relocation. PIC relocs in the data section are
799 * already in target order
801 if ((flags & FLAT_FLAG_GOTPIC) == 0) {
803 * Meh, the same value can have a different
804 * byte order based on a flag..
806 addr = ntohl((__force __be32)addr);
808 addr = calc_reloc(addr, libinfo);
809 if (addr == RELOC_FAILED) {
814 /* Write back the relocated pointer. */
815 ret = flat_put_addr_at_rp(rp, addr, relval);
820 #ifdef CONFIG_BINFMT_FLAT_OLD
822 for (i = 0; i < relocs; i++) {
824 if (get_user(relval, reloc + i))
826 old_reloc(ntohl(relval));
828 #endif /* CONFIG_BINFMT_FLAT_OLD */
831 flush_icache_user_range(start_code, end_code);
833 /* zero the BSS, BRK and stack areas */
834 if (clear_user((void __user *)(datapos + data_len), bss_len +
835 (memp + memp_size - stack_len - /* end brk */
836 libinfo->lib_list[0].start_brk) + /* start brk */
846 /****************************************************************************/
849 * These are the functions used to load flat style executables and shared
850 * libraries. There is no binary dependent code anywhere else.
853 static int load_flat_binary(struct linux_binprm *bprm)
855 struct lib_info libinfo;
856 struct pt_regs *regs = current_pt_regs();
857 unsigned long stack_len = 0;
858 unsigned long start_addr;
862 memset(&libinfo, 0, sizeof(libinfo));
865 * We have to add the size of our arguments to our stack size
866 * otherwise it's too easy for users to create stack overflows
867 * by passing in a huge argument list. And yes, we have to be
868 * pedantic and include space for the argv/envp array as it may have
872 stack_len += PAGE_SIZE * MAX_ARG_PAGES - bprm->p; /* the strings */
874 stack_len += (bprm->argc + 1) * sizeof(char *); /* the argv array */
875 stack_len += (bprm->envc + 1) * sizeof(char *); /* the envp array */
876 stack_len = ALIGN(stack_len, FLAT_STACK_ALIGN);
878 res = load_flat_file(bprm, &libinfo, &stack_len);
882 /* Update data segment pointers for all libraries */
883 for (i = 0; i < MAX_SHARED_LIBS; i++) {
884 if (!libinfo.lib_list[i].loaded)
886 for (j = 0; j < MAX_SHARED_LIBS; j++) {
887 unsigned long val = libinfo.lib_list[j].loaded ?
888 libinfo.lib_list[j].start_data : UNLOADED_LIB;
889 unsigned long __user *p = (unsigned long __user *)
890 libinfo.lib_list[i].start_data;
892 if (put_user(val, p))
897 set_binfmt(&flat_format);
900 res = setup_arg_pages(bprm, STACK_TOP, EXSTACK_DEFAULT);
902 res = create_flat_tables(bprm, bprm->p);
904 /* Stash our initial stack pointer into the mm structure */
905 current->mm->start_stack =
906 ((current->mm->context.end_brk + stack_len + 3) & ~3) - 4;
907 pr_debug("sp=%lx\n", current->mm->start_stack);
909 /* copy the arg pages onto the stack */
910 res = transfer_args_to_stack(bprm, ¤t->mm->start_stack);
912 res = create_flat_tables(bprm, current->mm->start_stack);
917 /* Fake some return addresses to ensure the call chain will
918 * initialise library in order for us. We are required to call
919 * lib 1 first, then 2, ... and finally the main program (id 0).
921 start_addr = libinfo.lib_list[0].entry;
923 #ifdef FLAT_PLAT_INIT
924 FLAT_PLAT_INIT(regs);
928 pr_debug("start_thread(regs=0x%p, entry=0x%lx, start_stack=0x%lx)\n",
929 regs, start_addr, current->mm->start_stack);
930 start_thread(regs, start_addr, current->mm->start_stack);
935 /****************************************************************************/
937 static int __init init_flat_binfmt(void)
939 register_binfmt(&flat_format);
942 core_initcall(init_flat_binfmt);
944 /****************************************************************************/