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 (stack, data section and bss) needs to be aligned
60 * for the same reasons as SLAB memory is, and to the same amount.
61 * Avoid duplicating architecture specific code by using the same
62 * macro as with SLAB allocation:
64 #ifdef ARCH_SLAB_MINALIGN
65 #define FLAT_DATA_ALIGN (ARCH_SLAB_MINALIGN)
67 #define FLAT_DATA_ALIGN (sizeof(void *))
70 #define RELOC_FAILED 0xff00ff01 /* Relocation incorrect somewhere */
71 #define UNLOADED_LIB 0x7ff000ff /* Placeholder for unused library */
75 unsigned long start_code
; /* Start of text segment */
76 unsigned long start_data
; /* Start of data segment */
77 unsigned long start_brk
; /* End of data segment */
78 unsigned long text_len
; /* Length of text segment */
79 unsigned long entry
; /* Start address for this module */
80 unsigned long build_date
; /* When this one was compiled */
81 short loaded
; /* Has this library been loaded? */
82 } lib_list
[MAX_SHARED_LIBS
];
85 #ifdef CONFIG_BINFMT_SHARED_FLAT
86 static int load_flat_shared_library(int id
, struct lib_info
*p
);
89 static int load_flat_binary(struct linux_binprm
*, struct pt_regs
* regs
);
90 static int flat_core_dump(struct coredump_params
*cprm
);
92 static struct linux_binfmt flat_format
= {
93 .module
= THIS_MODULE
,
94 .load_binary
= load_flat_binary
,
95 .core_dump
= flat_core_dump
,
96 .min_coredump
= PAGE_SIZE
99 /****************************************************************************/
101 * Routine writes a core dump image in the current directory.
102 * Currently only a stub-function.
105 static int flat_core_dump(struct coredump_params
*cprm
)
107 printk("Process %s:%d received signr %d and should have core dumped\n",
108 current
->comm
, current
->pid
, (int) cprm
->signr
);
112 /****************************************************************************/
114 * create_flat_tables() parses the env- and arg-strings in new user
115 * memory and creates the pointer tables from them, and puts their
116 * addresses on the "stack", returning the new stack pointer value.
119 static unsigned long create_flat_tables(
121 struct linux_binprm
* bprm
)
123 unsigned long *argv
,*envp
;
125 char * p
= (char*)pp
;
126 int argc
= bprm
->argc
;
127 int envc
= bprm
->envc
;
128 char uninitialized_var(dummy
);
130 sp
= (unsigned long *)p
;
131 sp
-= (envc
+ argc
+ 2) + 1 + (flat_argvp_envp_on_stack() ? 2 : 0);
132 sp
= (unsigned long *) ((unsigned long)sp
& -FLAT_DATA_ALIGN
);
133 argv
= sp
+ 1 + (flat_argvp_envp_on_stack() ? 2 : 0);
134 envp
= argv
+ (argc
+ 1);
136 if (flat_argvp_envp_on_stack()) {
137 put_user((unsigned long) envp
, sp
+ 2);
138 put_user((unsigned long) argv
, sp
+ 1);
142 current
->mm
->arg_start
= (unsigned long) p
;
144 put_user((unsigned long) p
, argv
++);
146 get_user(dummy
, p
); p
++;
149 put_user((unsigned long) NULL
, argv
);
150 current
->mm
->arg_end
= current
->mm
->env_start
= (unsigned long) p
;
152 put_user((unsigned long)p
, envp
); envp
++;
154 get_user(dummy
, p
); p
++;
157 put_user((unsigned long) NULL
, envp
);
158 current
->mm
->env_end
= (unsigned long) p
;
159 return (unsigned long)sp
;
162 /****************************************************************************/
164 #ifdef CONFIG_BINFMT_ZFLAT
166 #include <linux/zlib.h>
168 #define LBUFSIZE 4000
171 #define ASCII_FLAG 0x01 /* bit 0 set: file probably ASCII text */
172 #define CONTINUATION 0x02 /* bit 1 set: continuation of multi-part gzip file */
173 #define EXTRA_FIELD 0x04 /* bit 2 set: extra field present */
174 #define ORIG_NAME 0x08 /* bit 3 set: original file name present */
175 #define COMMENT 0x10 /* bit 4 set: file comment present */
176 #define ENCRYPTED 0x20 /* bit 5 set: file is encrypted */
177 #define RESERVED 0xC0 /* bit 6,7: reserved */
179 static int decompress_exec(
180 struct linux_binprm
*bprm
,
181 unsigned long offset
,
191 DBG_FLT("decompress_exec(offset=%x,buf=%x,len=%x)\n",(int)offset
, (int)dst
, (int)len
);
193 memset(&strm
, 0, sizeof(strm
));
194 strm
.workspace
= kmalloc(zlib_inflate_workspacesize(), GFP_KERNEL
);
195 if (strm
.workspace
== NULL
) {
196 DBG_FLT("binfmt_flat: no memory for decompress workspace\n");
199 buf
= kmalloc(LBUFSIZE
, GFP_KERNEL
);
201 DBG_FLT("binfmt_flat: no memory for read buffer\n");
206 /* Read in first chunk of data and parse gzip header. */
208 ret
= bprm
->file
->f_op
->read(bprm
->file
, buf
, LBUFSIZE
, &fpos
);
216 /* Check minimum size -- gzip header */
218 DBG_FLT("binfmt_flat: file too small?\n");
222 /* Check gzip magic number */
223 if ((buf
[0] != 037) || ((buf
[1] != 0213) && (buf
[1] != 0236))) {
224 DBG_FLT("binfmt_flat: unknown compression magic?\n");
228 /* Check gzip method */
230 DBG_FLT("binfmt_flat: unknown compression method?\n");
233 /* Check gzip flags */
234 if ((buf
[3] & ENCRYPTED
) || (buf
[3] & CONTINUATION
) ||
235 (buf
[3] & RESERVED
)) {
236 DBG_FLT("binfmt_flat: unknown flags?\n");
241 if (buf
[3] & EXTRA_FIELD
) {
242 ret
+= 2 + buf
[10] + (buf
[11] << 8);
243 if (unlikely(LBUFSIZE
<= ret
)) {
244 DBG_FLT("binfmt_flat: buffer overflow (EXTRA)?\n");
248 if (buf
[3] & ORIG_NAME
) {
249 while (ret
< LBUFSIZE
&& buf
[ret
++] != 0)
251 if (unlikely(LBUFSIZE
== ret
)) {
252 DBG_FLT("binfmt_flat: buffer overflow (ORIG_NAME)?\n");
256 if (buf
[3] & COMMENT
) {
257 while (ret
< LBUFSIZE
&& buf
[ret
++] != 0)
259 if (unlikely(LBUFSIZE
== ret
)) {
260 DBG_FLT("binfmt_flat: buffer overflow (COMMENT)?\n");
266 strm
.avail_in
-= ret
;
269 strm
.avail_out
= len
;
272 if (zlib_inflateInit2(&strm
, -MAX_WBITS
) != Z_OK
) {
273 DBG_FLT("binfmt_flat: zlib init failed?\n");
277 while ((ret
= zlib_inflate(&strm
, Z_NO_FLUSH
)) == Z_OK
) {
278 ret
= bprm
->file
->f_op
->read(bprm
->file
, buf
, LBUFSIZE
, &fpos
);
289 DBG_FLT("binfmt_flat: 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 printk("BINFMT_FLAT: reference 0x%x to shared library %d",
332 printk("BINFMT_FLAT: reloc address 0x%x not in same module "
333 "(%d != %d)", (unsigned) r
, curid
, id
);
335 } else if ( ! p
->lib_list
[id
].loaded
&&
336 IS_ERR_VALUE(load_flat_shared_library(id
, p
))) {
337 printk("BINFMT_FLAT: failed to load library %d", id
);
340 /* Check versioning information (i.e. time stamps) */
341 if (p
->lib_list
[id
].build_date
&& p
->lib_list
[curid
].build_date
&&
342 p
->lib_list
[curid
].build_date
< p
->lib_list
[id
].build_date
) {
343 printk("BINFMT_FLAT: library %d is younger than %d", id
, curid
);
351 start_brk
= p
->lib_list
[id
].start_brk
;
352 start_data
= p
->lib_list
[id
].start_data
;
353 start_code
= p
->lib_list
[id
].start_code
;
354 text_len
= p
->lib_list
[id
].text_len
;
356 if (!flat_reloc_valid(r
, start_brk
- start_data
+ text_len
)) {
357 printk("BINFMT_FLAT: reloc outside program 0x%x (0 - 0x%x/0x%x)",
358 (int) r
,(int)(start_brk
-start_data
+text_len
),(int)text_len
);
362 if (r
< text_len
) /* In text segment */
363 addr
= r
+ start_code
;
364 else /* In data segment */
365 addr
= r
- text_len
+ start_data
;
367 /* Range checked already above so doing the range tests is redundant...*/
371 printk(", killing %s!\n", current
->comm
);
372 send_sig(SIGSEGV
, current
, 0);
377 /****************************************************************************/
379 void old_reloc(unsigned long rl
)
382 char *segment
[] = { "TEXT", "DATA", "BSS", "*UNKNOWN*" };
388 #if defined(CONFIG_COLDFIRE)
389 ptr
= (unsigned long *) (current
->mm
->start_code
+ r
.reloc
.offset
);
391 ptr
= (unsigned long *) (current
->mm
->start_data
+ r
.reloc
.offset
);
395 printk("Relocation of variable at DATASEG+%x "
396 "(address %p, currently %x) into segment %s\n",
397 r
.reloc
.offset
, ptr
, (int)*ptr
, segment
[r
.reloc
.type
]);
400 switch (r
.reloc
.type
) {
401 case OLD_FLAT_RELOC_TYPE_TEXT
:
402 *ptr
+= current
->mm
->start_code
;
404 case OLD_FLAT_RELOC_TYPE_DATA
:
405 *ptr
+= current
->mm
->start_data
;
407 case OLD_FLAT_RELOC_TYPE_BSS
:
408 *ptr
+= current
->mm
->end_data
;
411 printk("BINFMT_FLAT: Unknown relocation type=%x\n", r
.reloc
.type
);
416 printk("Relocation became %x\n", (int)*ptr
);
420 /****************************************************************************/
422 static int load_flat_file(struct linux_binprm
* bprm
,
423 struct lib_info
*libinfo
, int id
, unsigned long *extra_stack
)
425 struct flat_hdr
* hdr
;
426 unsigned long textpos
= 0, datapos
= 0, result
;
427 unsigned long realdatastart
= 0;
428 unsigned long text_len
, data_len
, bss_len
, stack_len
, flags
;
429 unsigned long len
, memp
= 0;
430 unsigned long memp_size
, extra
, rlim
;
431 unsigned long *reloc
= 0, *rp
;
433 int i
, rev
, relocs
= 0;
435 unsigned long start_code
, end_code
;
438 hdr
= ((struct flat_hdr
*) bprm
->buf
); /* exec-header */
439 inode
= bprm
->file
->f_path
.dentry
->d_inode
;
441 text_len
= ntohl(hdr
->data_start
);
442 data_len
= ntohl(hdr
->data_end
) - ntohl(hdr
->data_start
);
443 bss_len
= ntohl(hdr
->bss_end
) - ntohl(hdr
->data_end
);
444 stack_len
= ntohl(hdr
->stack_size
);
446 stack_len
+= *extra_stack
;
447 *extra_stack
= stack_len
;
449 relocs
= ntohl(hdr
->reloc_count
);
450 flags
= ntohl(hdr
->flags
);
451 rev
= ntohl(hdr
->rev
);
453 if (strncmp(hdr
->magic
, "bFLT", 4)) {
455 * Previously, here was a printk to tell people
456 * "BINFMT_FLAT: bad header magic".
457 * But for the kernel which also use ELF FD-PIC format, this
458 * error message is confusing.
459 * because a lot of people do not manage to produce good
465 if (flags
& FLAT_FLAG_KTRACE
)
466 printk("BINFMT_FLAT: Loading file: %s\n", bprm
->filename
);
468 if (rev
!= FLAT_VERSION
&& rev
!= OLD_FLAT_VERSION
) {
469 printk("BINFMT_FLAT: bad flat file version 0x%x (supported "
470 "0x%lx and 0x%lx)\n",
471 rev
, FLAT_VERSION
, OLD_FLAT_VERSION
);
476 /* Don't allow old format executables to use shared libraries */
477 if (rev
== OLD_FLAT_VERSION
&& id
!= 0) {
478 printk("BINFMT_FLAT: shared libraries are not available before rev 0x%x\n",
485 * fix up the flags for the older format, there were all kinds
486 * of endian hacks, this only works for the simple cases
488 if (rev
== OLD_FLAT_VERSION
&& flat_old_ram_flag(flags
))
489 flags
= FLAT_FLAG_RAM
;
491 #ifndef CONFIG_BINFMT_ZFLAT
492 if (flags
& (FLAT_FLAG_GZIP
|FLAT_FLAG_GZDATA
)) {
493 printk("Support for ZFLAT executables is not enabled.\n");
500 * Check initial limits. This avoids letting people circumvent
501 * size limits imposed on them by creating programs with large
502 * arrays in the data or bss.
504 rlim
= rlimit(RLIMIT_DATA
);
505 if (rlim
>= RLIM_INFINITY
)
507 if (data_len
+ bss_len
> rlim
) {
512 /* Flush all traces of the currently running executable */
514 result
= flush_old_exec(bprm
);
520 /* OK, This is the point of no return */
521 set_personality(PER_LINUX_32BIT
);
522 setup_new_exec(bprm
);
526 * calculate the extra space we need to map in
528 extra
= max_t(unsigned long, bss_len
+ stack_len
,
529 relocs
* sizeof(unsigned long));
532 * there are a couple of cases here, the separate code/data
533 * case, and then the fully copied to RAM case which lumps
536 if ((flags
& (FLAT_FLAG_RAM
|FLAT_FLAG_GZIP
)) == 0) {
538 * this should give us a ROM ptr, but if it doesn't we don't
541 DBG_FLT("BINFMT_FLAT: ROM mapping of file (we hope)\n");
543 down_write(¤t
->mm
->mmap_sem
);
544 textpos
= do_mmap(bprm
->file
, 0, text_len
, PROT_READ
|PROT_EXEC
,
545 MAP_PRIVATE
|MAP_EXECUTABLE
, 0);
546 up_write(¤t
->mm
->mmap_sem
);
547 if (!textpos
|| IS_ERR_VALUE(textpos
)) {
549 textpos
= (unsigned long) -ENOMEM
;
550 printk("Unable to mmap process text, errno %d\n", (int)-textpos
);
555 len
= data_len
+ extra
+ MAX_SHARED_LIBS
* sizeof(unsigned long);
556 len
= PAGE_ALIGN(len
);
557 down_write(¤t
->mm
->mmap_sem
);
558 realdatastart
= do_mmap(0, 0, len
,
559 PROT_READ
|PROT_WRITE
|PROT_EXEC
, MAP_PRIVATE
, 0);
560 up_write(¤t
->mm
->mmap_sem
);
562 if (realdatastart
== 0 || IS_ERR_VALUE(realdatastart
)) {
564 realdatastart
= (unsigned long) -ENOMEM
;
565 printk("Unable to allocate RAM for process data, errno %d\n",
566 (int)-realdatastart
);
567 do_munmap(current
->mm
, textpos
, text_len
);
571 datapos
= ALIGN(realdatastart
+
572 MAX_SHARED_LIBS
* sizeof(unsigned long),
575 DBG_FLT("BINFMT_FLAT: Allocated data+bss+stack (%d bytes): %x\n",
576 (int)(data_len
+ bss_len
+ stack_len
), (int)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
,
582 data_len
+ (relocs
* sizeof(unsigned long)), 0);
586 result
= bprm
->file
->f_op
->read(bprm
->file
, (char *) datapos
,
587 data_len
+ (relocs
* sizeof(unsigned long)), &fpos
);
589 if (IS_ERR_VALUE(result
)) {
590 printk("Unable to read data+bss, errno %d\n", (int)-result
);
591 do_munmap(current
->mm
, textpos
, text_len
);
592 do_munmap(current
->mm
, realdatastart
, data_len
+ extra
);
597 reloc
= (unsigned long *) (datapos
+(ntohl(hdr
->reloc_start
)-text_len
));
598 memp
= realdatastart
;
602 len
= text_len
+ data_len
+ extra
+ MAX_SHARED_LIBS
* sizeof(unsigned long);
603 len
= PAGE_ALIGN(len
);
604 down_write(¤t
->mm
->mmap_sem
);
605 textpos
= do_mmap(0, 0, len
,
606 PROT_READ
| PROT_EXEC
| PROT_WRITE
, MAP_PRIVATE
, 0);
607 up_write(¤t
->mm
->mmap_sem
);
609 if (!textpos
|| IS_ERR_VALUE(textpos
)) {
611 textpos
= (unsigned long) -ENOMEM
;
612 printk("Unable to allocate RAM for process text/data, errno %d\n",
618 realdatastart
= textpos
+ ntohl(hdr
->data_start
);
619 datapos
= ALIGN(realdatastart
+
620 MAX_SHARED_LIBS
* sizeof(unsigned long),
623 reloc
= (unsigned long *)
624 (datapos
+ (ntohl(hdr
->reloc_start
) - text_len
));
627 #ifdef CONFIG_BINFMT_ZFLAT
629 * load it all in and treat it like a RAM load from now on
631 if (flags
& FLAT_FLAG_GZIP
) {
632 result
= decompress_exec(bprm
, sizeof (struct flat_hdr
),
633 (((char *) textpos
) + sizeof (struct flat_hdr
)),
634 (text_len
+ data_len
+ (relocs
* sizeof(unsigned long))
635 - sizeof (struct flat_hdr
)),
637 memmove((void *) datapos
, (void *) realdatastart
,
638 data_len
+ (relocs
* sizeof(unsigned long)));
639 } else if (flags
& FLAT_FLAG_GZDATA
) {
641 result
= bprm
->file
->f_op
->read(bprm
->file
,
642 (char *) textpos
, text_len
, &fpos
);
643 if (!IS_ERR_VALUE(result
))
644 result
= decompress_exec(bprm
, text_len
, (char *) datapos
,
645 data_len
+ (relocs
* sizeof(unsigned long)), 0);
651 result
= bprm
->file
->f_op
->read(bprm
->file
,
652 (char *) textpos
, text_len
, &fpos
);
653 if (!IS_ERR_VALUE(result
)) {
654 fpos
= ntohl(hdr
->data_start
);
655 result
= bprm
->file
->f_op
->read(bprm
->file
, (char *) datapos
,
656 data_len
+ (relocs
* sizeof(unsigned long)), &fpos
);
659 if (IS_ERR_VALUE(result
)) {
660 printk("Unable to read code+data+bss, errno %d\n",(int)-result
);
661 do_munmap(current
->mm
, textpos
, text_len
+ data_len
+ extra
+
662 MAX_SHARED_LIBS
* sizeof(unsigned long));
668 if (flags
& FLAT_FLAG_KTRACE
)
669 printk("Mapping is %x, Entry point is %x, data_start is %x\n",
670 (int)textpos
, 0x00ffffff&ntohl(hdr
->entry
), ntohl(hdr
->data_start
));
672 /* The main program needs a little extra setup in the task structure */
673 start_code
= textpos
+ sizeof (struct flat_hdr
);
674 end_code
= textpos
+ text_len
;
676 current
->mm
->start_code
= start_code
;
677 current
->mm
->end_code
= end_code
;
678 current
->mm
->start_data
= datapos
;
679 current
->mm
->end_data
= datapos
+ data_len
;
681 * set up the brk stuff, uses any slack left in data/bss/stack
682 * allocation. We put the brk after the bss (between the bss
683 * and stack) like other platforms.
684 * Userspace code relies on the stack pointer starting out at
685 * an address right at the end of a page.
687 current
->mm
->start_brk
= datapos
+ data_len
+ bss_len
;
688 current
->mm
->brk
= (current
->mm
->start_brk
+ 3) & ~3;
689 current
->mm
->context
.end_brk
= memp
+ memp_size
- stack_len
;
692 if (flags
& FLAT_FLAG_KTRACE
)
693 printk("%s %s: TEXT=%x-%x DATA=%x-%x BSS=%x-%x\n",
694 id
? "Lib" : "Load", bprm
->filename
,
695 (int) start_code
, (int) end_code
,
697 (int) (datapos
+ data_len
),
698 (int) (datapos
+ data_len
),
699 (int) (((datapos
+ data_len
+ bss_len
) + 3) & ~3));
701 text_len
-= sizeof(struct flat_hdr
); /* the real code len */
703 /* Store the current module values into the global library structure */
704 libinfo
->lib_list
[id
].start_code
= start_code
;
705 libinfo
->lib_list
[id
].start_data
= datapos
;
706 libinfo
->lib_list
[id
].start_brk
= datapos
+ data_len
+ bss_len
;
707 libinfo
->lib_list
[id
].text_len
= text_len
;
708 libinfo
->lib_list
[id
].loaded
= 1;
709 libinfo
->lib_list
[id
].entry
= (0x00ffffff & ntohl(hdr
->entry
)) + textpos
;
710 libinfo
->lib_list
[id
].build_date
= ntohl(hdr
->build_date
);
713 * We just load the allocations into some temporary memory to
714 * help simplify all this mumbo jumbo
716 * We've got two different sections of relocation entries.
717 * The first is the GOT which resides at the begining of the data segment
718 * and is terminated with a -1. This one can be relocated in place.
719 * The second is the extra relocation entries tacked after the image's
720 * data segment. These require a little more processing as the entry is
721 * really an offset into the image which contains an offset into the
724 if (flags
& FLAT_FLAG_GOTPIC
) {
725 for (rp
= (unsigned long *)datapos
; *rp
!= 0xffffffff; rp
++) {
728 addr
= calc_reloc(*rp
, libinfo
, id
, 0);
729 if (addr
== RELOC_FAILED
) {
739 * Now run through the relocation entries.
740 * We've got to be careful here as C++ produces relocatable zero
741 * entries in the constructor and destructor tables which are then
742 * tested for being not zero (which will always occur unless we're
743 * based from address zero). This causes an endless loop as __start
744 * is at zero. The solution used is to not relocate zero addresses.
745 * This has the negative side effect of not allowing a global data
746 * reference to be statically initialised to _stext (I've moved
747 * __start to address 4 so that is okay).
749 if (rev
> OLD_FLAT_VERSION
) {
750 unsigned long persistent
= 0;
751 for (i
=0; i
< relocs
; i
++) {
752 unsigned long addr
, relval
;
754 /* Get the address of the pointer to be
755 relocated (of course, the address has to be
757 relval
= ntohl(reloc
[i
]);
758 if (flat_set_persistent (relval
, &persistent
))
760 addr
= flat_get_relocate_addr(relval
);
761 rp
= (unsigned long *) calc_reloc(addr
, libinfo
, id
, 1);
762 if (rp
== (unsigned long *)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 old_reloc(ntohl(reloc
[i
]));
792 flush_icache_range(start_code
, end_code
);
794 /* zero the BSS, BRK and stack areas */
795 memset((void*)(datapos
+ data_len
), 0, bss_len
+
796 (memp
+ memp_size
- stack_len
- /* end brk */
797 libinfo
->lib_list
[id
].start_brk
) + /* start brk */
806 /****************************************************************************/
807 #ifdef CONFIG_BINFMT_SHARED_FLAT
810 * Load a shared library into memory. The library gets its own data
811 * segment (including bss) but not argv/argc/environ.
814 static int load_flat_shared_library(int id
, struct lib_info
*libs
)
816 struct linux_binprm bprm
;
820 /* Create the file name */
821 sprintf(buf
, "/lib/lib%d.so", id
);
823 /* Open the file up */
825 bprm
.file
= open_exec(bprm
.filename
);
826 res
= PTR_ERR(bprm
.file
);
827 if (IS_ERR(bprm
.file
))
830 bprm
.cred
= prepare_exec_creds();
835 res
= prepare_binprm(&bprm
);
837 if (!IS_ERR_VALUE(res
))
838 res
= load_flat_file(&bprm
, libs
, id
, NULL
);
840 abort_creds(bprm
.cred
);
843 allow_write_access(bprm
.file
);
849 #endif /* CONFIG_BINFMT_SHARED_FLAT */
850 /****************************************************************************/
853 * These are the functions used to load flat style executables and shared
854 * libraries. There is no binary dependent code anywhere else.
857 static int load_flat_binary(struct linux_binprm
* bprm
, struct pt_regs
* regs
)
859 struct lib_info libinfo
;
860 unsigned long p
= bprm
->p
;
861 unsigned long stack_len
;
862 unsigned long start_addr
;
867 memset(&libinfo
, 0, sizeof(libinfo
));
869 * We have to add the size of our arguments to our stack size
870 * otherwise it's too easy for users to create stack overflows
871 * by passing in a huge argument list. And yes, we have to be
872 * pedantic and include space for the argv/envp array as it may have
875 #define TOP_OF_ARGS (PAGE_SIZE * MAX_ARG_PAGES - sizeof(void *))
876 stack_len
= TOP_OF_ARGS
- bprm
->p
; /* the strings */
877 stack_len
+= (bprm
->argc
+ 1) * sizeof(char *); /* the argv array */
878 stack_len
+= (bprm
->envc
+ 1) * sizeof(char *); /* the envp array */
879 stack_len
+= FLAT_DATA_ALIGN
- 1; /* reserve for upcoming alignment */
881 res
= load_flat_file(bprm
, &libinfo
, 0, &stack_len
);
882 if (IS_ERR_VALUE(res
))
885 /* Update data segment pointers for all libraries */
886 for (i
=0; i
<MAX_SHARED_LIBS
; i
++)
887 if (libinfo
.lib_list
[i
].loaded
)
888 for (j
=0; j
<MAX_SHARED_LIBS
; j
++)
889 (-(j
+1))[(unsigned long *)(libinfo
.lib_list
[i
].start_data
)] =
890 (libinfo
.lib_list
[j
].loaded
)?
891 libinfo
.lib_list
[j
].start_data
:UNLOADED_LIB
;
893 install_exec_creds(bprm
);
894 current
->flags
&= ~PF_FORKNOEXEC
;
896 set_binfmt(&flat_format
);
898 p
= ((current
->mm
->context
.end_brk
+ stack_len
+ 3) & ~3) - 4;
899 DBG_FLT("p=%x\n", (int)p
);
901 /* copy the arg pages onto the stack, this could be more efficient :-) */
902 for (i
= TOP_OF_ARGS
- 1; i
>= bprm
->p
; i
--)
904 ((char *) page_address(bprm
->page
[i
/PAGE_SIZE
]))[i
% PAGE_SIZE
];
906 sp
= (unsigned long *) create_flat_tables(p
, bprm
);
908 /* Fake some return addresses to ensure the call chain will
909 * initialise library in order for us. We are required to call
910 * lib 1 first, then 2, ... and finally the main program (id 0).
912 start_addr
= libinfo
.lib_list
[0].entry
;
914 #ifdef CONFIG_BINFMT_SHARED_FLAT
915 for (i
= MAX_SHARED_LIBS
-1; i
>0; i
--) {
916 if (libinfo
.lib_list
[i
].loaded
) {
917 /* Push previos first to call address */
918 --sp
; put_user(start_addr
, sp
);
919 start_addr
= libinfo
.lib_list
[i
].entry
;
924 /* Stash our initial stack pointer into the mm structure */
925 current
->mm
->start_stack
= (unsigned long )sp
;
927 #ifdef FLAT_PLAT_INIT
928 FLAT_PLAT_INIT(regs
);
930 DBG_FLT("start_thread(regs=0x%x, entry=0x%x, start_stack=0x%x)\n",
931 (int)regs
, (int)start_addr
, (int)current
->mm
->start_stack
);
933 start_thread(regs
, start_addr
, current
->mm
->start_stack
);
938 /****************************************************************************/
940 static int __init
init_flat_binfmt(void)
942 return register_binfmt(&flat_format
);
945 /****************************************************************************/
947 core_initcall(init_flat_binfmt
);
949 /****************************************************************************/
This page took 0.050265 seconds and 5 git commands to generate.