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/kernel.h>
20
#include <linux/sched.h>
22
#include <linux/mman.h>
23
#include <linux/errno.h>
24
#include <linux/signal.h>
25
#include <linux/string.h>
27
#include <linux/file.h>
28
#include <linux/stat.h>
29
#include <linux/fcntl.h>
30
#include <linux/ptrace.h>
31
#include <linux/user.h>
32
#include <linux/slab.h>
33
#include <linux/binfmts.h>
34
#include <linux/personality.h>
35
#include <linux/init.h>
36
#include <linux/flat.h>
37
#include <linux/syscalls.h>
39
#include <asm/byteorder.h>
40
#include <asm/system.h>
41
#include <asm/uaccess.h>
42
#include <asm/unaligned.h>
43
#include <asm/cacheflush.h>
46
/****************************************************************************/
53
#define DBG_FLT(a...) printk(a)
59
* User data (data section and bss) needs to be aligned.
60
* We pick 0x20 here because it is the max value elf2flt has always
61
* used in producing FLAT files, and because it seems to be large
62
* enough to make all the gcc alignment related tests happy.
64
#define FLAT_DATA_ALIGN (0x20)
67
* User data (stack) also needs to be aligned.
68
* Here we can be a bit looser than the data sections since this
69
* needs to only meet arch ABI requirements.
71
#define FLAT_STACK_ALIGN max_t(unsigned long, sizeof(void *), ARCH_SLAB_MINALIGN)
73
#define RELOC_FAILED 0xff00ff01 /* Relocation incorrect somewhere */
74
#define UNLOADED_LIB 0x7ff000ff /* Placeholder for unused library */
78
unsigned long start_code; /* Start of text segment */
79
unsigned long start_data; /* Start of data segment */
80
unsigned long start_brk; /* End of data segment */
81
unsigned long text_len; /* Length of text segment */
82
unsigned long entry; /* Start address for this module */
83
unsigned long build_date; /* When this one was compiled */
84
short loaded; /* Has this library been loaded? */
85
} lib_list[MAX_SHARED_LIBS];
88
#ifdef CONFIG_BINFMT_SHARED_FLAT
89
static int load_flat_shared_library(int id, struct lib_info *p);
92
static int load_flat_binary(struct linux_binprm *, struct pt_regs * regs);
93
static int flat_core_dump(struct coredump_params *cprm);
95
static struct linux_binfmt flat_format = {
96
.module = THIS_MODULE,
97
.load_binary = load_flat_binary,
98
.core_dump = flat_core_dump,
99
.min_coredump = PAGE_SIZE
102
/****************************************************************************/
104
* Routine writes a core dump image in the current directory.
105
* Currently only a stub-function.
108
static int flat_core_dump(struct coredump_params *cprm)
110
printk("Process %s:%d received signr %d and should have core dumped\n",
111
current->comm, current->pid, (int) cprm->signr);
115
/****************************************************************************/
117
* create_flat_tables() parses the env- and arg-strings in new user
118
* memory and creates the pointer tables from them, and puts their
119
* addresses on the "stack", returning the new stack pointer value.
122
static unsigned long create_flat_tables(
124
struct linux_binprm * bprm)
126
unsigned long *argv,*envp;
128
char * p = (char*)pp;
129
int argc = bprm->argc;
130
int envc = bprm->envc;
131
char uninitialized_var(dummy);
133
sp = (unsigned long *)p;
134
sp -= (envc + argc + 2) + 1 + (flat_argvp_envp_on_stack() ? 2 : 0);
135
sp = (unsigned long *) ((unsigned long)sp & -FLAT_STACK_ALIGN);
136
argv = sp + 1 + (flat_argvp_envp_on_stack() ? 2 : 0);
137
envp = argv + (argc + 1);
139
if (flat_argvp_envp_on_stack()) {
140
put_user((unsigned long) envp, sp + 2);
141
put_user((unsigned long) argv, sp + 1);
145
current->mm->arg_start = (unsigned long) p;
147
put_user((unsigned long) p, argv++);
149
get_user(dummy, p); p++;
152
put_user((unsigned long) NULL, argv);
153
current->mm->arg_end = current->mm->env_start = (unsigned long) p;
155
put_user((unsigned long)p, envp); envp++;
157
get_user(dummy, p); p++;
160
put_user((unsigned long) NULL, envp);
161
current->mm->env_end = (unsigned long) p;
162
return (unsigned long)sp;
165
/****************************************************************************/
167
#ifdef CONFIG_BINFMT_ZFLAT
169
#include <linux/zlib.h>
171
#define LBUFSIZE 4000
174
#define ASCII_FLAG 0x01 /* bit 0 set: file probably ASCII text */
175
#define CONTINUATION 0x02 /* bit 1 set: continuation of multi-part gzip file */
176
#define EXTRA_FIELD 0x04 /* bit 2 set: extra field present */
177
#define ORIG_NAME 0x08 /* bit 3 set: original file name present */
178
#define COMMENT 0x10 /* bit 4 set: file comment present */
179
#define ENCRYPTED 0x20 /* bit 5 set: file is encrypted */
180
#define RESERVED 0xC0 /* bit 6,7: reserved */
182
static int decompress_exec(
183
struct linux_binprm *bprm,
184
unsigned long offset,
194
DBG_FLT("decompress_exec(offset=%x,buf=%x,len=%x)\n",(int)offset, (int)dst, (int)len);
196
memset(&strm, 0, sizeof(strm));
197
strm.workspace = kmalloc(zlib_inflate_workspacesize(), GFP_KERNEL);
198
if (strm.workspace == NULL) {
199
DBG_FLT("binfmt_flat: no memory for decompress workspace\n");
202
buf = kmalloc(LBUFSIZE, GFP_KERNEL);
204
DBG_FLT("binfmt_flat: no memory for read buffer\n");
209
/* Read in first chunk of data and parse gzip header. */
211
ret = bprm->file->f_op->read(bprm->file, buf, LBUFSIZE, &fpos);
219
/* Check minimum size -- gzip header */
221
DBG_FLT("binfmt_flat: file too small?\n");
225
/* Check gzip magic number */
226
if ((buf[0] != 037) || ((buf[1] != 0213) && (buf[1] != 0236))) {
227
DBG_FLT("binfmt_flat: unknown compression magic?\n");
231
/* Check gzip method */
233
DBG_FLT("binfmt_flat: unknown compression method?\n");
236
/* Check gzip flags */
237
if ((buf[3] & ENCRYPTED) || (buf[3] & CONTINUATION) ||
238
(buf[3] & RESERVED)) {
239
DBG_FLT("binfmt_flat: unknown flags?\n");
244
if (buf[3] & EXTRA_FIELD) {
245
ret += 2 + buf[10] + (buf[11] << 8);
246
if (unlikely(LBUFSIZE <= ret)) {
247
DBG_FLT("binfmt_flat: buffer overflow (EXTRA)?\n");
251
if (buf[3] & ORIG_NAME) {
252
while (ret < LBUFSIZE && buf[ret++] != 0)
254
if (unlikely(LBUFSIZE == ret)) {
255
DBG_FLT("binfmt_flat: buffer overflow (ORIG_NAME)?\n");
259
if (buf[3] & COMMENT) {
260
while (ret < LBUFSIZE && buf[ret++] != 0)
262
if (unlikely(LBUFSIZE == ret)) {
263
DBG_FLT("binfmt_flat: buffer overflow (COMMENT)?\n");
269
strm.avail_in -= ret;
272
strm.avail_out = len;
275
if (zlib_inflateInit2(&strm, -MAX_WBITS) != Z_OK) {
276
DBG_FLT("binfmt_flat: zlib init failed?\n");
280
while ((ret = zlib_inflate(&strm, Z_NO_FLUSH)) == Z_OK) {
281
ret = bprm->file->f_op->read(bprm->file, buf, LBUFSIZE, &fpos);
292
DBG_FLT("binfmt_flat: decompression failed (%d), %s\n",
299
zlib_inflateEnd(&strm);
303
kfree(strm.workspace);
307
#endif /* CONFIG_BINFMT_ZFLAT */
309
/****************************************************************************/
312
calc_reloc(unsigned long r, struct lib_info *p, int curid, int internalp)
316
unsigned long start_brk;
317
unsigned long start_data;
318
unsigned long text_len;
319
unsigned long start_code;
321
#ifdef CONFIG_BINFMT_SHARED_FLAT
323
id = curid; /* Relocs of 0 are always self referring */
325
id = (r >> 24) & 0xff; /* Find ID for this reloc */
326
r &= 0x00ffffff; /* Trim ID off here */
328
if (id >= MAX_SHARED_LIBS) {
329
printk("BINFMT_FLAT: reference 0x%x to shared library %d",
335
printk("BINFMT_FLAT: reloc address 0x%x not in same module "
336
"(%d != %d)", (unsigned) r, curid, id);
338
} else if ( ! p->lib_list[id].loaded &&
339
IS_ERR_VALUE(load_flat_shared_library(id, p))) {
340
printk("BINFMT_FLAT: failed to load library %d", id);
343
/* Check versioning information (i.e. time stamps) */
344
if (p->lib_list[id].build_date && p->lib_list[curid].build_date &&
345
p->lib_list[curid].build_date < p->lib_list[id].build_date) {
346
printk("BINFMT_FLAT: library %d is younger than %d", id, curid);
354
start_brk = p->lib_list[id].start_brk;
355
start_data = p->lib_list[id].start_data;
356
start_code = p->lib_list[id].start_code;
357
text_len = p->lib_list[id].text_len;
359
if (!flat_reloc_valid(r, start_brk - start_data + text_len)) {
360
printk("BINFMT_FLAT: reloc outside program 0x%x (0 - 0x%x/0x%x)",
361
(int) r,(int)(start_brk-start_data+text_len),(int)text_len);
365
if (r < text_len) /* In text segment */
366
addr = r + start_code;
367
else /* In data segment */
368
addr = r - text_len + start_data;
370
/* Range checked already above so doing the range tests is redundant...*/
374
printk(", killing %s!\n", current->comm);
375
send_sig(SIGSEGV, current, 0);
380
/****************************************************************************/
382
void old_reloc(unsigned long rl)
385
char *segment[] = { "TEXT", "DATA", "BSS", "*UNKNOWN*" };
391
#if defined(CONFIG_COLDFIRE)
392
ptr = (unsigned long *) (current->mm->start_code + r.reloc.offset);
394
ptr = (unsigned long *) (current->mm->start_data + r.reloc.offset);
398
printk("Relocation of variable at DATASEG+%x "
399
"(address %p, currently %x) into segment %s\n",
400
r.reloc.offset, ptr, (int)*ptr, segment[r.reloc.type]);
403
switch (r.reloc.type) {
404
case OLD_FLAT_RELOC_TYPE_TEXT:
405
*ptr += current->mm->start_code;
407
case OLD_FLAT_RELOC_TYPE_DATA:
408
*ptr += current->mm->start_data;
410
case OLD_FLAT_RELOC_TYPE_BSS:
411
*ptr += current->mm->end_data;
414
printk("BINFMT_FLAT: Unknown relocation type=%x\n", r.reloc.type);
419
printk("Relocation became %x\n", (int)*ptr);
423
/****************************************************************************/
425
static int load_flat_file(struct linux_binprm * bprm,
426
struct lib_info *libinfo, int id, unsigned long *extra_stack)
428
struct flat_hdr * hdr;
429
unsigned long textpos = 0, datapos = 0, result;
430
unsigned long realdatastart = 0;
431
unsigned long text_len, data_len, bss_len, stack_len, flags;
432
unsigned long len, memp = 0;
433
unsigned long memp_size, extra, rlim;
434
unsigned long *reloc = 0, *rp;
436
int i, rev, relocs = 0;
438
unsigned long start_code, end_code;
441
hdr = ((struct flat_hdr *) bprm->buf); /* exec-header */
442
inode = bprm->file->f_path.dentry->d_inode;
444
text_len = ntohl(hdr->data_start);
445
data_len = ntohl(hdr->data_end) - ntohl(hdr->data_start);
446
bss_len = ntohl(hdr->bss_end) - ntohl(hdr->data_end);
447
stack_len = ntohl(hdr->stack_size);
449
stack_len += *extra_stack;
450
*extra_stack = stack_len;
452
relocs = ntohl(hdr->reloc_count);
453
flags = ntohl(hdr->flags);
454
rev = ntohl(hdr->rev);
456
if (strncmp(hdr->magic, "bFLT", 4)) {
458
* Previously, here was a printk to tell people
459
* "BINFMT_FLAT: bad header magic".
460
* But for the kernel which also use ELF FD-PIC format, this
461
* error message is confusing.
462
* because a lot of people do not manage to produce good
468
if (flags & FLAT_FLAG_KTRACE)
469
printk("BINFMT_FLAT: Loading file: %s\n", bprm->filename);
471
if (rev != FLAT_VERSION && rev != OLD_FLAT_VERSION) {
472
printk("BINFMT_FLAT: bad flat file version 0x%x (supported "
473
"0x%lx and 0x%lx)\n",
474
rev, FLAT_VERSION, OLD_FLAT_VERSION);
479
/* Don't allow old format executables to use shared libraries */
480
if (rev == OLD_FLAT_VERSION && id != 0) {
481
printk("BINFMT_FLAT: shared libraries are not available before rev 0x%x\n",
488
* fix up the flags for the older format, there were all kinds
489
* of endian hacks, this only works for the simple cases
491
if (rev == OLD_FLAT_VERSION && flat_old_ram_flag(flags))
492
flags = FLAT_FLAG_RAM;
494
#ifndef CONFIG_BINFMT_ZFLAT
495
if (flags & (FLAT_FLAG_GZIP|FLAT_FLAG_GZDATA)) {
496
printk("Support for ZFLAT executables is not enabled.\n");
503
* Check initial limits. This avoids letting people circumvent
504
* size limits imposed on them by creating programs with large
505
* arrays in the data or bss.
507
rlim = rlimit(RLIMIT_DATA);
508
if (rlim >= RLIM_INFINITY)
510
if (data_len + bss_len > rlim) {
515
/* Flush all traces of the currently running executable */
517
result = flush_old_exec(bprm);
523
/* OK, This is the point of no return */
524
set_personality(PER_LINUX_32BIT);
525
setup_new_exec(bprm);
529
* calculate the extra space we need to map in
531
extra = max_t(unsigned long, bss_len + stack_len,
532
relocs * sizeof(unsigned long));
535
* there are a couple of cases here, the separate code/data
536
* case, and then the fully copied to RAM case which lumps
539
if ((flags & (FLAT_FLAG_RAM|FLAT_FLAG_GZIP)) == 0) {
541
* this should give us a ROM ptr, but if it doesn't we don't
544
DBG_FLT("BINFMT_FLAT: ROM mapping of file (we hope)\n");
546
down_write(¤t->mm->mmap_sem);
547
textpos = do_mmap(bprm->file, 0, text_len, PROT_READ|PROT_EXEC,
548
MAP_PRIVATE|MAP_EXECUTABLE, 0);
549
up_write(¤t->mm->mmap_sem);
550
if (!textpos || IS_ERR_VALUE(textpos)) {
552
textpos = (unsigned long) -ENOMEM;
553
printk("Unable to mmap process text, errno %d\n", (int)-textpos);
558
len = data_len + extra + MAX_SHARED_LIBS * sizeof(unsigned long);
559
len = PAGE_ALIGN(len);
560
down_write(¤t->mm->mmap_sem);
561
realdatastart = do_mmap(0, 0, len,
562
PROT_READ|PROT_WRITE|PROT_EXEC, MAP_PRIVATE, 0);
563
up_write(¤t->mm->mmap_sem);
565
if (realdatastart == 0 || IS_ERR_VALUE(realdatastart)) {
567
realdatastart = (unsigned long) -ENOMEM;
568
printk("Unable to allocate RAM for process data, errno %d\n",
569
(int)-realdatastart);
570
do_munmap(current->mm, textpos, text_len);
574
datapos = ALIGN(realdatastart +
575
MAX_SHARED_LIBS * sizeof(unsigned long),
578
DBG_FLT("BINFMT_FLAT: Allocated data+bss+stack (%d bytes): %x\n",
579
(int)(data_len + bss_len + stack_len), (int)datapos);
581
fpos = ntohl(hdr->data_start);
582
#ifdef CONFIG_BINFMT_ZFLAT
583
if (flags & FLAT_FLAG_GZDATA) {
584
result = decompress_exec(bprm, fpos, (char *) datapos,
585
data_len + (relocs * sizeof(unsigned long)), 0);
589
result = bprm->file->f_op->read(bprm->file, (char *) datapos,
590
data_len + (relocs * sizeof(unsigned long)), &fpos);
592
if (IS_ERR_VALUE(result)) {
593
printk("Unable to read data+bss, errno %d\n", (int)-result);
594
do_munmap(current->mm, textpos, text_len);
595
do_munmap(current->mm, realdatastart, len);
600
reloc = (unsigned long *) (datapos+(ntohl(hdr->reloc_start)-text_len));
601
memp = realdatastart;
605
len = text_len + data_len + extra + MAX_SHARED_LIBS * sizeof(unsigned long);
606
len = PAGE_ALIGN(len);
607
down_write(¤t->mm->mmap_sem);
608
textpos = do_mmap(0, 0, len,
609
PROT_READ | PROT_EXEC | PROT_WRITE, MAP_PRIVATE, 0);
610
up_write(¤t->mm->mmap_sem);
612
if (!textpos || IS_ERR_VALUE(textpos)) {
614
textpos = (unsigned long) -ENOMEM;
615
printk("Unable to allocate RAM for process text/data, errno %d\n",
621
realdatastart = textpos + ntohl(hdr->data_start);
622
datapos = ALIGN(realdatastart +
623
MAX_SHARED_LIBS * sizeof(unsigned long),
626
reloc = (unsigned long *)
627
(datapos + (ntohl(hdr->reloc_start) - text_len));
630
#ifdef CONFIG_BINFMT_ZFLAT
632
* load it all in and treat it like a RAM load from now on
634
if (flags & FLAT_FLAG_GZIP) {
635
result = decompress_exec(bprm, sizeof (struct flat_hdr),
636
(((char *) textpos) + sizeof (struct flat_hdr)),
637
(text_len + data_len + (relocs * sizeof(unsigned long))
638
- sizeof (struct flat_hdr)),
640
memmove((void *) datapos, (void *) realdatastart,
641
data_len + (relocs * sizeof(unsigned long)));
642
} else if (flags & FLAT_FLAG_GZDATA) {
644
result = bprm->file->f_op->read(bprm->file,
645
(char *) textpos, text_len, &fpos);
646
if (!IS_ERR_VALUE(result))
647
result = decompress_exec(bprm, text_len, (char *) datapos,
648
data_len + (relocs * sizeof(unsigned long)), 0);
654
result = bprm->file->f_op->read(bprm->file,
655
(char *) textpos, text_len, &fpos);
656
if (!IS_ERR_VALUE(result)) {
657
fpos = ntohl(hdr->data_start);
658
result = bprm->file->f_op->read(bprm->file, (char *) datapos,
659
data_len + (relocs * sizeof(unsigned long)), &fpos);
662
if (IS_ERR_VALUE(result)) {
663
printk("Unable to read code+data+bss, errno %d\n",(int)-result);
664
do_munmap(current->mm, textpos, text_len + data_len + extra +
665
MAX_SHARED_LIBS * sizeof(unsigned long));
671
if (flags & FLAT_FLAG_KTRACE)
672
printk("Mapping is %x, Entry point is %x, data_start is %x\n",
673
(int)textpos, 0x00ffffff&ntohl(hdr->entry), ntohl(hdr->data_start));
675
/* The main program needs a little extra setup in the task structure */
676
start_code = textpos + sizeof (struct flat_hdr);
677
end_code = textpos + text_len;
679
current->mm->start_code = start_code;
680
current->mm->end_code = end_code;
681
current->mm->start_data = datapos;
682
current->mm->end_data = datapos + data_len;
684
* set up the brk stuff, uses any slack left in data/bss/stack
685
* allocation. We put the brk after the bss (between the bss
686
* and stack) like other platforms.
687
* Userspace code relies on the stack pointer starting out at
688
* an address right at the end of a page.
690
current->mm->start_brk = datapos + data_len + bss_len;
691
current->mm->brk = (current->mm->start_brk + 3) & ~3;
692
current->mm->context.end_brk = memp + memp_size - stack_len;
695
if (flags & FLAT_FLAG_KTRACE)
696
printk("%s %s: TEXT=%x-%x DATA=%x-%x BSS=%x-%x\n",
697
id ? "Lib" : "Load", bprm->filename,
698
(int) start_code, (int) end_code,
700
(int) (datapos + data_len),
701
(int) (datapos + data_len),
702
(int) (((datapos + data_len + bss_len) + 3) & ~3));
704
text_len -= sizeof(struct flat_hdr); /* the real code len */
706
/* Store the current module values into the global library structure */
707
libinfo->lib_list[id].start_code = start_code;
708
libinfo->lib_list[id].start_data = datapos;
709
libinfo->lib_list[id].start_brk = datapos + data_len + bss_len;
710
libinfo->lib_list[id].text_len = text_len;
711
libinfo->lib_list[id].loaded = 1;
712
libinfo->lib_list[id].entry = (0x00ffffff & ntohl(hdr->entry)) + textpos;
713
libinfo->lib_list[id].build_date = ntohl(hdr->build_date);
716
* We just load the allocations into some temporary memory to
717
* help simplify all this mumbo jumbo
719
* We've got two different sections of relocation entries.
720
* The first is the GOT which resides at the beginning of the data segment
721
* and is terminated with a -1. This one can be relocated in place.
722
* The second is the extra relocation entries tacked after the image's
723
* data segment. These require a little more processing as the entry is
724
* really an offset into the image which contains an offset into the
727
if (flags & FLAT_FLAG_GOTPIC) {
728
for (rp = (unsigned long *)datapos; *rp != 0xffffffff; rp++) {
731
addr = calc_reloc(*rp, libinfo, id, 0);
732
if (addr == RELOC_FAILED) {
742
* Now run through the relocation entries.
743
* We've got to be careful here as C++ produces relocatable zero
744
* entries in the constructor and destructor tables which are then
745
* tested for being not zero (which will always occur unless we're
746
* based from address zero). This causes an endless loop as __start
747
* is at zero. The solution used is to not relocate zero addresses.
748
* This has the negative side effect of not allowing a global data
749
* reference to be statically initialised to _stext (I've moved
750
* __start to address 4 so that is okay).
752
if (rev > OLD_FLAT_VERSION) {
753
unsigned long persistent = 0;
754
for (i=0; i < relocs; i++) {
755
unsigned long addr, relval;
757
/* Get the address of the pointer to be
758
relocated (of course, the address has to be
760
relval = ntohl(reloc[i]);
761
if (flat_set_persistent (relval, &persistent))
763
addr = flat_get_relocate_addr(relval);
764
rp = (unsigned long *) calc_reloc(addr, libinfo, id, 1);
765
if (rp == (unsigned long *)RELOC_FAILED) {
770
/* Get the pointer's value. */
771
addr = flat_get_addr_from_rp(rp, relval, flags,
775
* Do the relocation. PIC relocs in the data section are
776
* already in target order
778
if ((flags & FLAT_FLAG_GOTPIC) == 0)
780
addr = calc_reloc(addr, libinfo, id, 0);
781
if (addr == RELOC_FAILED) {
786
/* Write back the relocated pointer. */
787
flat_put_addr_at_rp(rp, addr, relval);
791
for (i=0; i < relocs; i++)
792
old_reloc(ntohl(reloc[i]));
795
flush_icache_range(start_code, end_code);
797
/* zero the BSS, BRK and stack areas */
798
memset((void*)(datapos + data_len), 0, bss_len +
799
(memp + memp_size - stack_len - /* end brk */
800
libinfo->lib_list[id].start_brk) + /* start brk */
809
/****************************************************************************/
810
#ifdef CONFIG_BINFMT_SHARED_FLAT
813
* Load a shared library into memory. The library gets its own data
814
* segment (including bss) but not argv/argc/environ.
817
static int load_flat_shared_library(int id, struct lib_info *libs)
819
struct linux_binprm bprm;
823
memset(&bprm, 0, sizeof(bprm));
825
/* Create the file name */
826
sprintf(buf, "/lib/lib%d.so", id);
828
/* Open the file up */
830
bprm.file = open_exec(bprm.filename);
831
res = PTR_ERR(bprm.file);
832
if (IS_ERR(bprm.file))
835
bprm.cred = prepare_exec_creds();
840
/* We don't really care about recalculating credentials at this point
841
* as we're past the point of no return and are dealing with shared
844
bprm.cred_prepared = 1;
846
res = prepare_binprm(&bprm);
848
if (!IS_ERR_VALUE(res))
849
res = load_flat_file(&bprm, libs, id, NULL);
851
abort_creds(bprm.cred);
854
allow_write_access(bprm.file);
860
#endif /* CONFIG_BINFMT_SHARED_FLAT */
861
/****************************************************************************/
864
* These are the functions used to load flat style executables and shared
865
* libraries. There is no binary dependent code anywhere else.
868
static int load_flat_binary(struct linux_binprm * bprm, struct pt_regs * regs)
870
struct lib_info libinfo;
871
unsigned long p = bprm->p;
872
unsigned long stack_len;
873
unsigned long start_addr;
878
memset(&libinfo, 0, sizeof(libinfo));
880
* We have to add the size of our arguments to our stack size
881
* otherwise it's too easy for users to create stack overflows
882
* by passing in a huge argument list. And yes, we have to be
883
* pedantic and include space for the argv/envp array as it may have
886
#define TOP_OF_ARGS (PAGE_SIZE * MAX_ARG_PAGES - sizeof(void *))
887
stack_len = TOP_OF_ARGS - bprm->p; /* the strings */
888
stack_len += (bprm->argc + 1) * sizeof(char *); /* the argv array */
889
stack_len += (bprm->envc + 1) * sizeof(char *); /* the envp array */
890
stack_len += FLAT_STACK_ALIGN - 1; /* reserve for upcoming alignment */
892
res = load_flat_file(bprm, &libinfo, 0, &stack_len);
893
if (IS_ERR_VALUE(res))
896
/* Update data segment pointers for all libraries */
897
for (i=0; i<MAX_SHARED_LIBS; i++)
898
if (libinfo.lib_list[i].loaded)
899
for (j=0; j<MAX_SHARED_LIBS; j++)
900
(-(j+1))[(unsigned long *)(libinfo.lib_list[i].start_data)] =
901
(libinfo.lib_list[j].loaded)?
902
libinfo.lib_list[j].start_data:UNLOADED_LIB;
904
install_exec_creds(bprm);
905
current->flags &= ~PF_FORKNOEXEC;
907
set_binfmt(&flat_format);
909
p = ((current->mm->context.end_brk + stack_len + 3) & ~3) - 4;
910
DBG_FLT("p=%x\n", (int)p);
912
/* copy the arg pages onto the stack, this could be more efficient :-) */
913
for (i = TOP_OF_ARGS - 1; i >= bprm->p; i--)
915
((char *) page_address(bprm->page[i/PAGE_SIZE]))[i % PAGE_SIZE];
917
sp = (unsigned long *) create_flat_tables(p, bprm);
919
/* Fake some return addresses to ensure the call chain will
920
* initialise library in order for us. We are required to call
921
* lib 1 first, then 2, ... and finally the main program (id 0).
923
start_addr = libinfo.lib_list[0].entry;
925
#ifdef CONFIG_BINFMT_SHARED_FLAT
926
for (i = MAX_SHARED_LIBS-1; i>0; i--) {
927
if (libinfo.lib_list[i].loaded) {
928
/* Push previos first to call address */
929
--sp; put_user(start_addr, sp);
930
start_addr = libinfo.lib_list[i].entry;
935
/* Stash our initial stack pointer into the mm structure */
936
current->mm->start_stack = (unsigned long )sp;
938
#ifdef FLAT_PLAT_INIT
939
FLAT_PLAT_INIT(regs);
941
DBG_FLT("start_thread(regs=0x%x, entry=0x%x, start_stack=0x%x)\n",
942
(int)regs, (int)start_addr, (int)current->mm->start_stack);
944
start_thread(regs, start_addr, current->mm->start_stack);
949
/****************************************************************************/
951
static int __init init_flat_binfmt(void)
953
return register_binfmt(&flat_format);
956
/****************************************************************************/
958
core_initcall(init_flat_binfmt);
960
/****************************************************************************/