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 #ifdef CONFIG_BINFMT_SHARED_FLAT
72 #define MAX_SHARED_LIBS (4)
74 #define MAX_SHARED_LIBS (1)
79 unsigned long start_code
; /* Start of text segment */
80 unsigned long start_data
; /* Start of data segment */
81 unsigned long start_brk
; /* End of data segment */
82 unsigned long text_len
; /* Length of text segment */
83 unsigned long entry
; /* Start address for this module */
84 unsigned long build_date
; /* When this one was compiled */
85 bool loaded
; /* Has this library been loaded? */
86 } lib_list
[MAX_SHARED_LIBS
];
89 #ifdef CONFIG_BINFMT_SHARED_FLAT
90 static int load_flat_shared_library(int id
, struct lib_info
*p
);
93 static int load_flat_binary(struct linux_binprm
*);
94 static int flat_core_dump(struct coredump_params
*cprm
);
96 static struct linux_binfmt flat_format
= {
97 .module
= THIS_MODULE
,
98 .load_binary
= load_flat_binary
,
99 .core_dump
= flat_core_dump
,
100 .min_coredump
= PAGE_SIZE
103 /****************************************************************************/
105 * Routine writes a core dump image in the current directory.
106 * Currently only a stub-function.
109 static int flat_core_dump(struct coredump_params
*cprm
)
111 pr_warn("Process %s:%d received signr %d and should have core dumped\n",
112 current
->comm
, current
->pid
, cprm
->siginfo
->si_signo
);
116 /****************************************************************************/
118 * create_flat_tables() parses the env- and arg-strings in new user
119 * memory and creates the pointer tables from them, and puts their
120 * addresses on the "stack", recording the new stack pointer value.
123 static int create_flat_tables(struct linux_binprm
*bprm
, unsigned long arg_start
)
126 unsigned long __user
*sp
;
129 p
= (char __user
*)arg_start
;
130 sp
= (unsigned long __user
*)current
->mm
->start_stack
;
132 sp
-= bprm
->envc
+ 1;
133 sp
-= bprm
->argc
+ 1;
134 if (IS_ENABLED(CONFIG_BINFMT_FLAT_ARGVP_ENVP_ON_STACK
))
135 sp
-= 2; /* argvp + envp */
138 current
->mm
->start_stack
= (unsigned long)sp
& -FLAT_STACK_ALIGN
;
139 sp
= (unsigned long __user
*)current
->mm
->start_stack
;
141 __put_user(bprm
->argc
, sp
++);
142 if (IS_ENABLED(CONFIG_BINFMT_FLAT_ARGVP_ENVP_ON_STACK
)) {
143 unsigned long argv
, envp
;
144 argv
= (unsigned long)(sp
+ 2);
145 envp
= (unsigned long)(sp
+ 2 + bprm
->argc
+ 1);
146 __put_user(argv
, sp
++);
147 __put_user(envp
, sp
++);
150 current
->mm
->arg_start
= (unsigned long)p
;
151 for (i
= bprm
->argc
; i
> 0; i
--) {
152 __put_user((unsigned long)p
, sp
++);
153 len
= strnlen_user(p
, MAX_ARG_STRLEN
);
154 if (!len
|| len
> MAX_ARG_STRLEN
)
159 current
->mm
->arg_end
= (unsigned long)p
;
161 current
->mm
->env_start
= (unsigned long) p
;
162 for (i
= bprm
->envc
; i
> 0; i
--) {
163 __put_user((unsigned long)p
, sp
++);
164 len
= strnlen_user(p
, MAX_ARG_STRLEN
);
165 if (!len
|| len
> MAX_ARG_STRLEN
)
170 current
->mm
->env_end
= (unsigned long)p
;
175 /****************************************************************************/
177 #ifdef CONFIG_BINFMT_ZFLAT
179 #include <linux/zlib.h>
181 #define LBUFSIZE 4000
184 #define ASCII_FLAG 0x01 /* bit 0 set: file probably ASCII text */
185 #define CONTINUATION 0x02 /* bit 1 set: continuation of multi-part gzip file */
186 #define EXTRA_FIELD 0x04 /* bit 2 set: extra field present */
187 #define ORIG_NAME 0x08 /* bit 3 set: original file name present */
188 #define COMMENT 0x10 /* bit 4 set: file comment present */
189 #define ENCRYPTED 0x20 /* bit 5 set: file is encrypted */
190 #define RESERVED 0xC0 /* bit 6,7: reserved */
192 static int decompress_exec(struct linux_binprm
*bprm
, loff_t fpos
, char *dst
,
199 pr_debug("decompress_exec(offset=%llx,buf=%p,len=%lx)\n", fpos
, dst
, len
);
201 memset(&strm
, 0, sizeof(strm
));
202 strm
.workspace
= kmalloc(zlib_inflate_workspacesize(), GFP_KERNEL
);
206 buf
= kmalloc(LBUFSIZE
, GFP_KERNEL
);
212 /* Read in first chunk of data and parse gzip header. */
213 ret
= kernel_read(bprm
->file
, buf
, LBUFSIZE
, &fpos
);
221 /* Check minimum size -- gzip header */
223 pr_debug("file too small?\n");
227 /* Check gzip magic number */
228 if ((buf
[0] != 037) || ((buf
[1] != 0213) && (buf
[1] != 0236))) {
229 pr_debug("unknown compression magic?\n");
233 /* Check gzip method */
235 pr_debug("unknown compression method?\n");
238 /* Check gzip flags */
239 if ((buf
[3] & ENCRYPTED
) || (buf
[3] & CONTINUATION
) ||
240 (buf
[3] & RESERVED
)) {
241 pr_debug("unknown flags?\n");
246 if (buf
[3] & EXTRA_FIELD
) {
247 ret
+= 2 + buf
[10] + (buf
[11] << 8);
248 if (unlikely(ret
>= LBUFSIZE
)) {
249 pr_debug("buffer overflow (EXTRA)?\n");
253 if (buf
[3] & ORIG_NAME
) {
254 while (ret
< LBUFSIZE
&& buf
[ret
++] != 0)
256 if (unlikely(ret
== LBUFSIZE
)) {
257 pr_debug("buffer overflow (ORIG_NAME)?\n");
261 if (buf
[3] & COMMENT
) {
262 while (ret
< LBUFSIZE
&& buf
[ret
++] != 0)
264 if (unlikely(ret
== LBUFSIZE
)) {
265 pr_debug("buffer overflow (COMMENT)?\n");
271 strm
.avail_in
-= ret
;
274 strm
.avail_out
= len
;
277 if (zlib_inflateInit2(&strm
, -MAX_WBITS
) != Z_OK
) {
278 pr_debug("zlib init failed?\n");
282 while ((ret
= zlib_inflate(&strm
, Z_NO_FLUSH
)) == Z_OK
) {
283 ret
= kernel_read(bprm
->file
, buf
, LBUFSIZE
, &fpos
);
294 pr_debug("decompression failed (%d), %s\n",
301 zlib_inflateEnd(&strm
);
305 kfree(strm
.workspace
);
309 #endif /* CONFIG_BINFMT_ZFLAT */
311 /****************************************************************************/
314 calc_reloc(unsigned long r
, struct lib_info
*p
, int curid
, int internalp
)
318 unsigned long start_brk
;
319 unsigned long start_data
;
320 unsigned long text_len
;
321 unsigned long start_code
;
323 #ifdef CONFIG_BINFMT_SHARED_FLAT
325 id
= curid
; /* Relocs of 0 are always self referring */
327 id
= (r
>> 24) & 0xff; /* Find ID for this reloc */
328 r
&= 0x00ffffff; /* Trim ID off here */
330 if (id
>= MAX_SHARED_LIBS
) {
331 pr_err("reference 0x%lx to shared library %d", r
, id
);
336 pr_err("reloc address 0x%lx not in same module "
337 "(%d != %d)", r
, curid
, id
);
339 } else if (!p
->lib_list
[id
].loaded
&&
340 load_flat_shared_library(id
, p
) < 0) {
341 pr_err("failed to load library %d", id
);
344 /* Check versioning information (i.e. time stamps) */
345 if (p
->lib_list
[id
].build_date
&& p
->lib_list
[curid
].build_date
&&
346 p
->lib_list
[curid
].build_date
< p
->lib_list
[id
].build_date
) {
347 pr_err("library %d is younger than %d", id
, curid
);
355 start_brk
= p
->lib_list
[id
].start_brk
;
356 start_data
= p
->lib_list
[id
].start_data
;
357 start_code
= p
->lib_list
[id
].start_code
;
358 text_len
= p
->lib_list
[id
].text_len
;
360 if (r
> start_brk
- start_data
+ text_len
) {
361 pr_err("reloc outside program 0x%lx (0 - 0x%lx/0x%lx)",
362 r
, start_brk
-start_data
+text_len
, text_len
);
366 if (r
< text_len
) /* In text segment */
367 addr
= r
+ start_code
;
368 else /* In data segment */
369 addr
= r
- text_len
+ start_data
;
371 /* Range checked already above so doing the range tests is redundant...*/
375 pr_cont(", killing %s!\n", current
->comm
);
376 send_sig(SIGSEGV
, current
, 0);
381 /****************************************************************************/
383 #ifdef CONFIG_BINFMT_FLAT_OLD
384 static void old_reloc(unsigned long rl
)
386 static const char *segment
[] = { "TEXT", "DATA", "BSS", "*UNKNOWN*" };
388 unsigned long __user
*ptr
;
392 #if defined(CONFIG_COLDFIRE)
393 ptr
= (unsigned long __user
*)(current
->mm
->start_code
+ r
.reloc
.offset
);
395 ptr
= (unsigned long __user
*)(current
->mm
->start_data
+ r
.reloc
.offset
);
399 pr_debug("Relocation of variable at DATASEG+%x "
400 "(address %p, currently %lx) into segment %s\n",
401 r
.reloc
.offset
, ptr
, val
, segment
[r
.reloc
.type
]);
403 switch (r
.reloc
.type
) {
404 case OLD_FLAT_RELOC_TYPE_TEXT
:
405 val
+= current
->mm
->start_code
;
407 case OLD_FLAT_RELOC_TYPE_DATA
:
408 val
+= current
->mm
->start_data
;
410 case OLD_FLAT_RELOC_TYPE_BSS
:
411 val
+= current
->mm
->end_data
;
414 pr_err("Unknown relocation type=%x\n", r
.reloc
.type
);
419 pr_debug("Relocation became %lx\n", val
);
421 #endif /* CONFIG_BINFMT_FLAT_OLD */
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
, datapos
, realdatastart
;
430 u32 text_len
, data_len
, bss_len
, stack_len
, full_data
, flags
;
431 unsigned long len
, memp
, memp_size
, extra
, rlim
;
432 __be32 __user
*reloc
;
437 unsigned long start_code
, end_code
;
441 hdr
= ((struct flat_hdr
*) bprm
->buf
); /* exec-header */
442 inode
= file_inode(bprm
->file
);
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
);
455 full_data
= data_len
+ relocs
* sizeof(unsigned long);
457 if (strncmp(hdr
->magic
, "bFLT", 4)) {
459 * Previously, here was a printk to tell people
460 * "BINFMT_FLAT: bad header magic".
461 * But for the kernel which also use ELF FD-PIC format, this
462 * error message is confusing.
463 * because a lot of people do not manage to produce good
469 if (flags
& FLAT_FLAG_KTRACE
)
470 pr_info("Loading file: %s\n", bprm
->filename
);
472 #ifdef CONFIG_BINFMT_FLAT_OLD
473 if (rev
!= FLAT_VERSION
&& rev
!= OLD_FLAT_VERSION
) {
474 pr_err("bad flat file version 0x%x (supported 0x%lx and 0x%lx)\n",
475 rev
, FLAT_VERSION
, OLD_FLAT_VERSION
);
480 /* Don't allow old format executables to use shared libraries */
481 if (rev
== OLD_FLAT_VERSION
&& id
!= 0) {
482 pr_err("shared libraries are not available before rev 0x%lx\n",
489 * fix up the flags for the older format, there were all kinds
490 * of endian hacks, this only works for the simple cases
492 if (rev
== OLD_FLAT_VERSION
&&
493 (flags
|| IS_ENABLED(CONFIG_BINFMT_FLAT_OLD_ALWAYS_RAM
)))
494 flags
= FLAT_FLAG_RAM
;
496 #else /* CONFIG_BINFMT_FLAT_OLD */
497 if (rev
!= FLAT_VERSION
) {
498 pr_err("bad flat file version 0x%x (supported 0x%lx)\n",
503 #endif /* !CONFIG_BINFMT_FLAT_OLD */
506 * Make sure the header params are sane.
507 * 28 bits (256 MB) is way more than reasonable in this case.
508 * If some top bits are set we have probable binary corruption.
510 if ((text_len
| data_len
| bss_len
| stack_len
| full_data
) >> 28) {
511 pr_err("bad header\n");
516 #ifndef CONFIG_BINFMT_ZFLAT
517 if (flags
& (FLAT_FLAG_GZIP
|FLAT_FLAG_GZDATA
)) {
518 pr_err("Support for ZFLAT executables is not enabled.\n");
525 * Check initial limits. This avoids letting people circumvent
526 * size limits imposed on them by creating programs with large
527 * arrays in the data or bss.
529 rlim
= rlimit(RLIMIT_DATA
);
530 if (rlim
>= RLIM_INFINITY
)
532 if (data_len
+ bss_len
> rlim
) {
537 /* Flush all traces of the currently running executable */
539 ret
= flush_old_exec(bprm
);
543 /* OK, This is the point of no return */
544 set_personality(PER_LINUX_32BIT
);
545 setup_new_exec(bprm
);
549 * calculate the extra space we need to map in
551 extra
= max_t(unsigned long, bss_len
+ stack_len
,
552 relocs
* sizeof(unsigned long));
555 * there are a couple of cases here, the separate code/data
556 * case, and then the fully copied to RAM case which lumps
559 if (!IS_ENABLED(CONFIG_MMU
) && !(flags
& (FLAT_FLAG_RAM
|FLAT_FLAG_GZIP
))) {
561 * this should give us a ROM ptr, but if it doesn't we don't
564 pr_debug("ROM mapping of file (we hope)\n");
566 textpos
= vm_mmap(bprm
->file
, 0, text_len
, PROT_READ
|PROT_EXEC
,
567 MAP_PRIVATE
|MAP_EXECUTABLE
, 0);
568 if (!textpos
|| IS_ERR_VALUE(textpos
)) {
572 pr_err("Unable to mmap process text, errno %d\n", ret
);
576 len
= data_len
+ extra
;
577 len
= PAGE_ALIGN(len
);
578 realdatastart
= vm_mmap(NULL
, 0, len
,
579 PROT_READ
|PROT_WRITE
|PROT_EXEC
, MAP_PRIVATE
, 0);
581 if (realdatastart
== 0 || IS_ERR_VALUE(realdatastart
)) {
585 pr_err("Unable to allocate RAM for process data, "
587 vm_munmap(textpos
, text_len
);
590 datapos
= ALIGN(realdatastart
, FLAT_DATA_ALIGN
);
592 pr_debug("Allocated data+bss+stack (%u bytes): %lx\n",
593 data_len
+ bss_len
+ stack_len
, datapos
);
595 fpos
= ntohl(hdr
->data_start
);
596 #ifdef CONFIG_BINFMT_ZFLAT
597 if (flags
& FLAT_FLAG_GZDATA
) {
598 result
= decompress_exec(bprm
, fpos
, (char *)datapos
,
603 result
= read_code(bprm
->file
, datapos
, fpos
,
606 if (IS_ERR_VALUE(result
)) {
608 pr_err("Unable to read data+bss, errno %d\n", ret
);
609 vm_munmap(textpos
, text_len
);
610 vm_munmap(realdatastart
, len
);
614 reloc
= (__be32 __user
*)
615 (datapos
+ (ntohl(hdr
->reloc_start
) - text_len
));
616 memp
= realdatastart
;
620 len
= text_len
+ data_len
+ extra
;
621 len
= PAGE_ALIGN(len
);
622 textpos
= vm_mmap(NULL
, 0, len
,
623 PROT_READ
| PROT_EXEC
| PROT_WRITE
, MAP_PRIVATE
, 0);
625 if (!textpos
|| IS_ERR_VALUE(textpos
)) {
629 pr_err("Unable to allocate RAM for process text/data, "
634 realdatastart
= textpos
+ ntohl(hdr
->data_start
);
635 datapos
= ALIGN(realdatastart
, FLAT_DATA_ALIGN
);
637 reloc
= (__be32 __user
*)
638 (datapos
+ (ntohl(hdr
->reloc_start
) - text_len
));
641 #ifdef CONFIG_BINFMT_ZFLAT
643 * load it all in and treat it like a RAM load from now on
645 if (flags
& FLAT_FLAG_GZIP
) {
647 result
= decompress_exec(bprm
, sizeof(struct flat_hdr
),
648 (((char *)textpos
) + sizeof(struct flat_hdr
)),
649 (text_len
+ full_data
650 - sizeof(struct flat_hdr
)),
652 if (datapos
!= realdatastart
)
653 memmove((void *)datapos
, (void *)realdatastart
,
657 * This is used on MMU systems mainly for testing.
658 * Let's use a kernel buffer to simplify things.
660 long unz_text_len
= text_len
- sizeof(struct flat_hdr
);
661 long unz_len
= unz_text_len
+ full_data
;
662 char *unz_data
= vmalloc(unz_len
);
666 result
= decompress_exec(bprm
, sizeof(struct flat_hdr
),
667 unz_data
, unz_len
, 0);
669 (copy_to_user((void __user
*)textpos
+ sizeof(struct flat_hdr
),
670 unz_data
, unz_text_len
) ||
671 copy_to_user((void __user
*)datapos
,
672 unz_data
+ unz_text_len
, full_data
)))
677 } else if (flags
& FLAT_FLAG_GZDATA
) {
678 result
= read_code(bprm
->file
, textpos
, 0, text_len
);
679 if (!IS_ERR_VALUE(result
)) {
681 result
= decompress_exec(bprm
, text_len
, (char *) datapos
,
684 char *unz_data
= vmalloc(full_data
);
688 result
= decompress_exec(bprm
, text_len
,
689 unz_data
, full_data
, 0);
691 copy_to_user((void __user
*)datapos
,
692 unz_data
, full_data
))
699 #endif /* CONFIG_BINFMT_ZFLAT */
701 result
= read_code(bprm
->file
, textpos
, 0, text_len
);
702 if (!IS_ERR_VALUE(result
))
703 result
= read_code(bprm
->file
, datapos
,
704 ntohl(hdr
->data_start
),
707 if (IS_ERR_VALUE(result
)) {
709 pr_err("Unable to read code+data+bss, errno %d\n", ret
);
710 vm_munmap(textpos
, text_len
+ data_len
+ extra
);
715 start_code
= textpos
+ sizeof(struct flat_hdr
);
716 end_code
= textpos
+ text_len
;
717 text_len
-= sizeof(struct flat_hdr
); /* the real code len */
719 /* The main program needs a little extra setup in the task structure */
721 current
->mm
->start_code
= start_code
;
722 current
->mm
->end_code
= end_code
;
723 current
->mm
->start_data
= datapos
;
724 current
->mm
->end_data
= datapos
+ data_len
;
726 * set up the brk stuff, uses any slack left in data/bss/stack
727 * allocation. We put the brk after the bss (between the bss
728 * and stack) like other platforms.
729 * Userspace code relies on the stack pointer starting out at
730 * an address right at the end of a page.
732 current
->mm
->start_brk
= datapos
+ data_len
+ bss_len
;
733 current
->mm
->brk
= (current
->mm
->start_brk
+ 3) & ~3;
735 current
->mm
->context
.end_brk
= memp
+ memp_size
- stack_len
;
739 if (flags
& FLAT_FLAG_KTRACE
) {
740 pr_info("Mapping is %lx, Entry point is %x, data_start is %x\n",
741 textpos
, 0x00ffffff&ntohl(hdr
->entry
), ntohl(hdr
->data_start
));
742 pr_info("%s %s: TEXT=%lx-%lx DATA=%lx-%lx BSS=%lx-%lx\n",
743 id
? "Lib" : "Load", bprm
->filename
,
744 start_code
, end_code
, datapos
, datapos
+ data_len
,
745 datapos
+ data_len
, (datapos
+ data_len
+ bss_len
+ 3) & ~3);
748 /* Store the current module values into the global library structure */
749 libinfo
->lib_list
[id
].start_code
= start_code
;
750 libinfo
->lib_list
[id
].start_data
= datapos
;
751 libinfo
->lib_list
[id
].start_brk
= datapos
+ data_len
+ bss_len
;
752 libinfo
->lib_list
[id
].text_len
= text_len
;
753 libinfo
->lib_list
[id
].loaded
= 1;
754 libinfo
->lib_list
[id
].entry
= (0x00ffffff & ntohl(hdr
->entry
)) + textpos
;
755 libinfo
->lib_list
[id
].build_date
= ntohl(hdr
->build_date
);
758 * We just load the allocations into some temporary memory to
759 * help simplify all this mumbo jumbo
761 * We've got two different sections of relocation entries.
762 * The first is the GOT which resides at the beginning of the data segment
763 * and is terminated with a -1. This one can be relocated in place.
764 * The second is the extra relocation entries tacked after the image's
765 * data segment. These require a little more processing as the entry is
766 * really an offset into the image which contains an offset into the
769 if (flags
& FLAT_FLAG_GOTPIC
) {
770 for (rp
= (u32 __user
*)datapos
; ; rp
++) {
772 if (get_user(rp_val
, rp
))
774 if (rp_val
== 0xffffffff)
777 addr
= calc_reloc(rp_val
, libinfo
, id
, 0);
778 if (addr
== RELOC_FAILED
) {
782 if (put_user(addr
, rp
))
789 * Now run through the relocation entries.
790 * We've got to be careful here as C++ produces relocatable zero
791 * entries in the constructor and destructor tables which are then
792 * tested for being not zero (which will always occur unless we're
793 * based from address zero). This causes an endless loop as __start
794 * is at zero. The solution used is to not relocate zero addresses.
795 * This has the negative side effect of not allowing a global data
796 * reference to be statically initialised to _stext (I've moved
797 * __start to address 4 so that is okay).
799 if (rev
> OLD_FLAT_VERSION
) {
800 for (i
= 0; i
< relocs
; i
++) {
805 * Get the address of the pointer to be
806 * relocated (of course, the address has to be
809 if (get_user(tmp
, reloc
+ i
))
812 addr
= flat_get_relocate_addr(relval
);
813 rp
= (u32 __user
*)calc_reloc(addr
, libinfo
, id
, 1);
814 if (rp
== (u32 __user
*)RELOC_FAILED
) {
819 /* Get the pointer's value. */
820 ret
= flat_get_addr_from_rp(rp
, relval
, flags
, &addr
);
826 * Do the relocation. PIC relocs in the data section are
827 * already in target order
829 if ((flags
& FLAT_FLAG_GOTPIC
) == 0) {
831 * Meh, the same value can have a different
832 * byte order based on a flag..
834 addr
= ntohl((__force __be32
)addr
);
836 addr
= calc_reloc(addr
, libinfo
, id
, 0);
837 if (addr
== RELOC_FAILED
) {
842 /* Write back the relocated pointer. */
843 ret
= flat_put_addr_at_rp(rp
, addr
, relval
);
848 #ifdef CONFIG_BINFMT_FLAT_OLD
850 for (i
= 0; i
< relocs
; i
++) {
852 if (get_user(relval
, reloc
+ i
))
854 old_reloc(ntohl(relval
));
856 #endif /* CONFIG_BINFMT_FLAT_OLD */
859 flush_icache_range(start_code
, end_code
);
861 /* zero the BSS, BRK and stack areas */
862 if (clear_user((void __user
*)(datapos
+ data_len
), bss_len
+
863 (memp
+ memp_size
- stack_len
- /* end brk */
864 libinfo
->lib_list
[id
].start_brk
) + /* start brk */
874 /****************************************************************************/
875 #ifdef CONFIG_BINFMT_SHARED_FLAT
878 * Load a shared library into memory. The library gets its own data
879 * segment (including bss) but not argv/argc/environ.
882 static int load_flat_shared_library(int id
, struct lib_info
*libs
)
885 * This is a fake bprm struct; only the members "buf", "file" and
886 * "filename" are actually used.
888 struct linux_binprm bprm
;
893 memset(&bprm
, 0, sizeof(bprm
));
895 /* Create the file name */
896 sprintf(buf
, "/lib/lib%d.so", id
);
898 /* Open the file up */
900 bprm
.file
= open_exec(bprm
.filename
);
901 res
= PTR_ERR(bprm
.file
);
902 if (IS_ERR(bprm
.file
))
905 res
= kernel_read(bprm
.file
, bprm
.buf
, BINPRM_BUF_SIZE
, &pos
);
908 res
= load_flat_file(&bprm
, libs
, id
, NULL
);
910 allow_write_access(bprm
.file
);
916 #endif /* CONFIG_BINFMT_SHARED_FLAT */
917 /****************************************************************************/
920 * These are the functions used to load flat style executables and shared
921 * libraries. There is no binary dependent code anywhere else.
924 static int load_flat_binary(struct linux_binprm
*bprm
)
926 struct lib_info libinfo
;
927 struct pt_regs
*regs
= current_pt_regs();
928 unsigned long stack_len
= 0;
929 unsigned long start_addr
;
933 memset(&libinfo
, 0, sizeof(libinfo
));
936 * We have to add the size of our arguments to our stack size
937 * otherwise it's too easy for users to create stack overflows
938 * by passing in a huge argument list. And yes, we have to be
939 * pedantic and include space for the argv/envp array as it may have
943 stack_len
+= PAGE_SIZE
* MAX_ARG_PAGES
- bprm
->p
; /* the strings */
945 stack_len
+= (bprm
->argc
+ 1) * sizeof(char *); /* the argv array */
946 stack_len
+= (bprm
->envc
+ 1) * sizeof(char *); /* the envp array */
947 stack_len
= ALIGN(stack_len
, FLAT_STACK_ALIGN
);
949 res
= load_flat_file(bprm
, &libinfo
, 0, &stack_len
);
953 /* Update data segment pointers for all libraries */
954 for (i
= 0; i
< MAX_SHARED_LIBS
; i
++) {
955 if (!libinfo
.lib_list
[i
].loaded
)
957 for (j
= 0; j
< MAX_SHARED_LIBS
; j
++) {
958 unsigned long val
= libinfo
.lib_list
[j
].loaded
?
959 libinfo
.lib_list
[j
].start_data
: UNLOADED_LIB
;
960 unsigned long __user
*p
= (unsigned long __user
*)
961 libinfo
.lib_list
[i
].start_data
;
963 if (put_user(val
, p
))
968 install_exec_creds(bprm
);
970 set_binfmt(&flat_format
);
973 res
= setup_arg_pages(bprm
, STACK_TOP
, EXSTACK_DEFAULT
);
975 res
= create_flat_tables(bprm
, bprm
->p
);
977 /* Stash our initial stack pointer into the mm structure */
978 current
->mm
->start_stack
=
979 ((current
->mm
->context
.end_brk
+ stack_len
+ 3) & ~3) - 4;
980 pr_debug("sp=%lx\n", current
->mm
->start_stack
);
982 /* copy the arg pages onto the stack */
983 res
= transfer_args_to_stack(bprm
, ¤t
->mm
->start_stack
);
985 res
= create_flat_tables(bprm
, current
->mm
->start_stack
);
990 /* Fake some return addresses to ensure the call chain will
991 * initialise library in order for us. We are required to call
992 * lib 1 first, then 2, ... and finally the main program (id 0).
994 start_addr
= libinfo
.lib_list
[0].entry
;
996 #ifdef CONFIG_BINFMT_SHARED_FLAT
997 for (i
= MAX_SHARED_LIBS
-1; i
> 0; i
--) {
998 if (libinfo
.lib_list
[i
].loaded
) {
999 /* Push previos first to call address */
1000 unsigned long __user
*sp
;
1001 current
->mm
->start_stack
-= sizeof(unsigned long);
1002 sp
= (unsigned long __user
*)current
->mm
->start_stack
;
1003 __put_user(start_addr
, sp
);
1004 start_addr
= libinfo
.lib_list
[i
].entry
;
1009 #ifdef FLAT_PLAT_INIT
1010 FLAT_PLAT_INIT(regs
);
1013 finalize_exec(bprm
);
1014 pr_debug("start_thread(regs=0x%p, entry=0x%lx, start_stack=0x%lx)\n",
1015 regs
, start_addr
, current
->mm
->start_stack
);
1016 start_thread(regs
, start_addr
, current
->mm
->start_stack
);
1021 /****************************************************************************/
1023 static int __init
init_flat_binfmt(void)
1025 register_binfmt(&flat_format
);
1028 core_initcall(init_flat_binfmt
);
1030 /****************************************************************************/