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)
77 #ifdef CONFIG_BINFMT_FLAT_NO_DATA_START_OFFSET
78 #define DATA_START_OFFSET_WORDS (0)
80 #define DATA_START_OFFSET_WORDS (MAX_SHARED_LIBS)
85 unsigned long start_code
; /* Start of text segment */
86 unsigned long start_data
; /* Start of data segment */
87 unsigned long start_brk
; /* End of data segment */
88 unsigned long text_len
; /* Length of text segment */
89 unsigned long entry
; /* Start address for this module */
90 unsigned long build_date
; /* When this one was compiled */
91 bool loaded
; /* Has this library been loaded? */
92 } lib_list
[MAX_SHARED_LIBS
];
95 #ifdef CONFIG_BINFMT_SHARED_FLAT
96 static int load_flat_shared_library(int id
, struct lib_info
*p
);
99 static int load_flat_binary(struct linux_binprm
*);
100 static int flat_core_dump(struct coredump_params
*cprm
);
102 static struct linux_binfmt flat_format
= {
103 .module
= THIS_MODULE
,
104 .load_binary
= load_flat_binary
,
105 .core_dump
= flat_core_dump
,
106 .min_coredump
= PAGE_SIZE
109 /****************************************************************************/
111 * Routine writes a core dump image in the current directory.
112 * Currently only a stub-function.
115 static int flat_core_dump(struct coredump_params
*cprm
)
117 pr_warn("Process %s:%d received signr %d and should have core dumped\n",
118 current
->comm
, current
->pid
, cprm
->siginfo
->si_signo
);
122 /****************************************************************************/
124 * create_flat_tables() parses the env- and arg-strings in new user
125 * memory and creates the pointer tables from them, and puts their
126 * addresses on the "stack", recording the new stack pointer value.
129 static int create_flat_tables(struct linux_binprm
*bprm
, unsigned long arg_start
)
132 unsigned long __user
*sp
;
135 p
= (char __user
*)arg_start
;
136 sp
= (unsigned long __user
*)current
->mm
->start_stack
;
138 sp
-= bprm
->envc
+ 1;
139 sp
-= bprm
->argc
+ 1;
140 if (IS_ENABLED(CONFIG_BINFMT_FLAT_ARGVP_ENVP_ON_STACK
))
141 sp
-= 2; /* argvp + envp */
144 current
->mm
->start_stack
= (unsigned long)sp
& -FLAT_STACK_ALIGN
;
145 sp
= (unsigned long __user
*)current
->mm
->start_stack
;
147 if (put_user(bprm
->argc
, sp
++))
149 if (IS_ENABLED(CONFIG_BINFMT_FLAT_ARGVP_ENVP_ON_STACK
)) {
150 unsigned long argv
, envp
;
151 argv
= (unsigned long)(sp
+ 2);
152 envp
= (unsigned long)(sp
+ 2 + bprm
->argc
+ 1);
153 if (put_user(argv
, sp
++) || put_user(envp
, sp
++))
157 current
->mm
->arg_start
= (unsigned long)p
;
158 for (i
= bprm
->argc
; i
> 0; i
--) {
159 if (put_user((unsigned long)p
, sp
++))
161 len
= strnlen_user(p
, MAX_ARG_STRLEN
);
162 if (!len
|| len
> MAX_ARG_STRLEN
)
166 if (put_user(0, sp
++))
168 current
->mm
->arg_end
= (unsigned long)p
;
170 current
->mm
->env_start
= (unsigned long) p
;
171 for (i
= bprm
->envc
; i
> 0; i
--) {
172 if (put_user((unsigned long)p
, sp
++))
174 len
= strnlen_user(p
, MAX_ARG_STRLEN
);
175 if (!len
|| len
> MAX_ARG_STRLEN
)
179 if (put_user(0, sp
++))
181 current
->mm
->env_end
= (unsigned long)p
;
186 /****************************************************************************/
188 #ifdef CONFIG_BINFMT_ZFLAT
190 #include <linux/zlib.h>
192 #define LBUFSIZE 4000
195 #define ASCII_FLAG 0x01 /* bit 0 set: file probably ASCII text */
196 #define CONTINUATION 0x02 /* bit 1 set: continuation of multi-part gzip file */
197 #define EXTRA_FIELD 0x04 /* bit 2 set: extra field present */
198 #define ORIG_NAME 0x08 /* bit 3 set: original file name present */
199 #define COMMENT 0x10 /* bit 4 set: file comment present */
200 #define ENCRYPTED 0x20 /* bit 5 set: file is encrypted */
201 #define RESERVED 0xC0 /* bit 6,7: reserved */
203 static int decompress_exec(struct linux_binprm
*bprm
, loff_t fpos
, char *dst
,
210 pr_debug("decompress_exec(offset=%llx,buf=%p,len=%lx)\n", fpos
, dst
, len
);
212 memset(&strm
, 0, sizeof(strm
));
213 strm
.workspace
= kmalloc(zlib_inflate_workspacesize(), GFP_KERNEL
);
217 buf
= kmalloc(LBUFSIZE
, GFP_KERNEL
);
223 /* Read in first chunk of data and parse gzip header. */
224 ret
= kernel_read(bprm
->file
, buf
, LBUFSIZE
, &fpos
);
232 /* Check minimum size -- gzip header */
234 pr_debug("file too small?\n");
238 /* Check gzip magic number */
239 if ((buf
[0] != 037) || ((buf
[1] != 0213) && (buf
[1] != 0236))) {
240 pr_debug("unknown compression magic?\n");
244 /* Check gzip method */
246 pr_debug("unknown compression method?\n");
249 /* Check gzip flags */
250 if ((buf
[3] & ENCRYPTED
) || (buf
[3] & CONTINUATION
) ||
251 (buf
[3] & RESERVED
)) {
252 pr_debug("unknown flags?\n");
257 if (buf
[3] & EXTRA_FIELD
) {
258 ret
+= 2 + buf
[10] + (buf
[11] << 8);
259 if (unlikely(ret
>= LBUFSIZE
)) {
260 pr_debug("buffer overflow (EXTRA)?\n");
264 if (buf
[3] & ORIG_NAME
) {
265 while (ret
< LBUFSIZE
&& buf
[ret
++] != 0)
267 if (unlikely(ret
== LBUFSIZE
)) {
268 pr_debug("buffer overflow (ORIG_NAME)?\n");
272 if (buf
[3] & COMMENT
) {
273 while (ret
< LBUFSIZE
&& buf
[ret
++] != 0)
275 if (unlikely(ret
== LBUFSIZE
)) {
276 pr_debug("buffer overflow (COMMENT)?\n");
282 strm
.avail_in
-= ret
;
285 strm
.avail_out
= len
;
288 if (zlib_inflateInit2(&strm
, -MAX_WBITS
) != Z_OK
) {
289 pr_debug("zlib init failed?\n");
293 while ((ret
= zlib_inflate(&strm
, Z_NO_FLUSH
)) == Z_OK
) {
294 ret
= kernel_read(bprm
->file
, buf
, LBUFSIZE
, &fpos
);
305 pr_debug("decompression failed (%d), %s\n",
312 zlib_inflateEnd(&strm
);
316 kfree(strm
.workspace
);
320 #endif /* CONFIG_BINFMT_ZFLAT */
322 /****************************************************************************/
325 calc_reloc(unsigned long r
, struct lib_info
*p
, int curid
, int internalp
)
329 unsigned long start_brk
;
330 unsigned long start_data
;
331 unsigned long text_len
;
332 unsigned long start_code
;
334 #ifdef CONFIG_BINFMT_SHARED_FLAT
336 id
= curid
; /* Relocs of 0 are always self referring */
338 id
= (r
>> 24) & 0xff; /* Find ID for this reloc */
339 r
&= 0x00ffffff; /* Trim ID off here */
341 if (id
>= MAX_SHARED_LIBS
) {
342 pr_err("reference 0x%lx to shared library %d", r
, id
);
347 pr_err("reloc address 0x%lx not in same module "
348 "(%d != %d)", r
, curid
, id
);
350 } else if (!p
->lib_list
[id
].loaded
&&
351 load_flat_shared_library(id
, p
) < 0) {
352 pr_err("failed to load library %d", id
);
355 /* Check versioning information (i.e. time stamps) */
356 if (p
->lib_list
[id
].build_date
&& p
->lib_list
[curid
].build_date
&&
357 p
->lib_list
[curid
].build_date
< p
->lib_list
[id
].build_date
) {
358 pr_err("library %d is younger than %d", id
, curid
);
366 start_brk
= p
->lib_list
[id
].start_brk
;
367 start_data
= p
->lib_list
[id
].start_data
;
368 start_code
= p
->lib_list
[id
].start_code
;
369 text_len
= p
->lib_list
[id
].text_len
;
371 if (r
> start_brk
- start_data
+ text_len
) {
372 pr_err("reloc outside program 0x%lx (0 - 0x%lx/0x%lx)",
373 r
, start_brk
-start_data
+text_len
, text_len
);
377 if (r
< text_len
) /* In text segment */
378 addr
= r
+ start_code
;
379 else /* In data segment */
380 addr
= r
- text_len
+ start_data
;
382 /* Range checked already above so doing the range tests is redundant...*/
386 pr_cont(", killing %s!\n", current
->comm
);
387 send_sig(SIGSEGV
, current
, 0);
392 /****************************************************************************/
394 #ifdef CONFIG_BINFMT_FLAT_OLD
395 static void old_reloc(unsigned long rl
)
397 static const char *segment
[] = { "TEXT", "DATA", "BSS", "*UNKNOWN*" };
399 unsigned long __user
*ptr
;
403 #if defined(CONFIG_COLDFIRE)
404 ptr
= (unsigned long __user
*)(current
->mm
->start_code
+ r
.reloc
.offset
);
406 ptr
= (unsigned long __user
*)(current
->mm
->start_data
+ r
.reloc
.offset
);
410 pr_debug("Relocation of variable at DATASEG+%x "
411 "(address %p, currently %lx) into segment %s\n",
412 r
.reloc
.offset
, ptr
, val
, segment
[r
.reloc
.type
]);
414 switch (r
.reloc
.type
) {
415 case OLD_FLAT_RELOC_TYPE_TEXT
:
416 val
+= current
->mm
->start_code
;
418 case OLD_FLAT_RELOC_TYPE_DATA
:
419 val
+= current
->mm
->start_data
;
421 case OLD_FLAT_RELOC_TYPE_BSS
:
422 val
+= current
->mm
->end_data
;
425 pr_err("Unknown relocation type=%x\n", r
.reloc
.type
);
430 pr_debug("Relocation became %lx\n", val
);
432 #endif /* CONFIG_BINFMT_FLAT_OLD */
434 /****************************************************************************/
436 static int load_flat_file(struct linux_binprm
*bprm
,
437 struct lib_info
*libinfo
, int id
, unsigned long *extra_stack
)
439 struct flat_hdr
*hdr
;
440 unsigned long textpos
, datapos
, realdatastart
;
441 u32 text_len
, data_len
, bss_len
, stack_len
, full_data
, flags
;
442 unsigned long len
, memp
, memp_size
, extra
, rlim
;
443 __be32 __user
*reloc
;
447 unsigned long start_code
, end_code
;
451 hdr
= ((struct flat_hdr
*) bprm
->buf
); /* exec-header */
453 text_len
= ntohl(hdr
->data_start
);
454 data_len
= ntohl(hdr
->data_end
) - ntohl(hdr
->data_start
);
455 bss_len
= ntohl(hdr
->bss_end
) - ntohl(hdr
->data_end
);
456 stack_len
= ntohl(hdr
->stack_size
);
458 stack_len
+= *extra_stack
;
459 *extra_stack
= stack_len
;
461 relocs
= ntohl(hdr
->reloc_count
);
462 flags
= ntohl(hdr
->flags
);
463 rev
= ntohl(hdr
->rev
);
464 full_data
= data_len
+ relocs
* sizeof(unsigned long);
466 if (strncmp(hdr
->magic
, "bFLT", 4)) {
468 * Previously, here was a printk to tell people
469 * "BINFMT_FLAT: bad header magic".
470 * But for the kernel which also use ELF FD-PIC format, this
471 * error message is confusing.
472 * because a lot of people do not manage to produce good
478 if (flags
& FLAT_FLAG_KTRACE
)
479 pr_info("Loading file: %s\n", bprm
->filename
);
481 #ifdef CONFIG_BINFMT_FLAT_OLD
482 if (rev
!= FLAT_VERSION
&& rev
!= OLD_FLAT_VERSION
) {
483 pr_err("bad flat file version 0x%x (supported 0x%lx and 0x%lx)\n",
484 rev
, FLAT_VERSION
, OLD_FLAT_VERSION
);
489 /* Don't allow old format executables to use shared libraries */
490 if (rev
== OLD_FLAT_VERSION
&& id
!= 0) {
491 pr_err("shared libraries are not available before rev 0x%lx\n",
498 * fix up the flags for the older format, there were all kinds
499 * of endian hacks, this only works for the simple cases
501 if (rev
== OLD_FLAT_VERSION
&&
502 (flags
|| IS_ENABLED(CONFIG_BINFMT_FLAT_OLD_ALWAYS_RAM
)))
503 flags
= FLAT_FLAG_RAM
;
505 #else /* CONFIG_BINFMT_FLAT_OLD */
506 if (rev
!= FLAT_VERSION
) {
507 pr_err("bad flat file version 0x%x (supported 0x%lx)\n",
512 #endif /* !CONFIG_BINFMT_FLAT_OLD */
515 * Make sure the header params are sane.
516 * 28 bits (256 MB) is way more than reasonable in this case.
517 * If some top bits are set we have probable binary corruption.
519 if ((text_len
| data_len
| bss_len
| stack_len
| full_data
) >> 28) {
520 pr_err("bad header\n");
525 #ifndef CONFIG_BINFMT_ZFLAT
526 if (flags
& (FLAT_FLAG_GZIP
|FLAT_FLAG_GZDATA
)) {
527 pr_err("Support for ZFLAT executables is not enabled.\n");
534 * Check initial limits. This avoids letting people circumvent
535 * size limits imposed on them by creating programs with large
536 * arrays in the data or bss.
538 rlim
= rlimit(RLIMIT_DATA
);
539 if (rlim
>= RLIM_INFINITY
)
541 if (data_len
+ bss_len
> rlim
) {
546 /* Flush all traces of the currently running executable */
548 ret
= begin_new_exec(bprm
);
552 /* OK, This is the point of no return */
553 set_personality(PER_LINUX_32BIT
);
554 setup_new_exec(bprm
);
558 * calculate the extra space we need to map in
560 extra
= max_t(unsigned long, bss_len
+ stack_len
,
561 relocs
* sizeof(unsigned long));
564 * there are a couple of cases here, the separate code/data
565 * case, and then the fully copied to RAM case which lumps
568 if (!IS_ENABLED(CONFIG_MMU
) && !(flags
& (FLAT_FLAG_RAM
|FLAT_FLAG_GZIP
))) {
570 * this should give us a ROM ptr, but if it doesn't we don't
573 pr_debug("ROM mapping of file (we hope)\n");
575 textpos
= vm_mmap(bprm
->file
, 0, text_len
, PROT_READ
|PROT_EXEC
,
577 if (!textpos
|| IS_ERR_VALUE(textpos
)) {
581 pr_err("Unable to mmap process text, errno %d\n", ret
);
585 len
= data_len
+ extra
+
586 DATA_START_OFFSET_WORDS
* sizeof(unsigned long);
587 len
= PAGE_ALIGN(len
);
588 realdatastart
= vm_mmap(NULL
, 0, len
,
589 PROT_READ
|PROT_WRITE
|PROT_EXEC
, MAP_PRIVATE
, 0);
591 if (realdatastart
== 0 || IS_ERR_VALUE(realdatastart
)) {
595 pr_err("Unable to allocate RAM for process data, "
597 vm_munmap(textpos
, text_len
);
600 datapos
= ALIGN(realdatastart
+
601 DATA_START_OFFSET_WORDS
* sizeof(unsigned long),
604 pr_debug("Allocated data+bss+stack (%u bytes): %lx\n",
605 data_len
+ bss_len
+ stack_len
, datapos
);
607 fpos
= ntohl(hdr
->data_start
);
608 #ifdef CONFIG_BINFMT_ZFLAT
609 if (flags
& FLAT_FLAG_GZDATA
) {
610 result
= decompress_exec(bprm
, fpos
, (char *)datapos
,
615 result
= read_code(bprm
->file
, datapos
, fpos
,
618 if (IS_ERR_VALUE(result
)) {
620 pr_err("Unable to read data+bss, errno %d\n", ret
);
621 vm_munmap(textpos
, text_len
);
622 vm_munmap(realdatastart
, len
);
626 reloc
= (__be32 __user
*)
627 (datapos
+ (ntohl(hdr
->reloc_start
) - text_len
));
628 memp
= realdatastart
;
632 len
= text_len
+ data_len
+ extra
+
633 DATA_START_OFFSET_WORDS
* sizeof(u32
);
634 len
= PAGE_ALIGN(len
);
635 textpos
= vm_mmap(NULL
, 0, len
,
636 PROT_READ
| PROT_EXEC
| PROT_WRITE
, MAP_PRIVATE
, 0);
638 if (!textpos
|| IS_ERR_VALUE(textpos
)) {
642 pr_err("Unable to allocate RAM for process text/data, "
647 realdatastart
= textpos
+ ntohl(hdr
->data_start
);
648 datapos
= ALIGN(realdatastart
+
649 DATA_START_OFFSET_WORDS
* sizeof(u32
),
652 reloc
= (__be32 __user
*)
653 (datapos
+ (ntohl(hdr
->reloc_start
) - text_len
));
656 #ifdef CONFIG_BINFMT_ZFLAT
658 * load it all in and treat it like a RAM load from now on
660 if (flags
& FLAT_FLAG_GZIP
) {
662 result
= decompress_exec(bprm
, sizeof(struct flat_hdr
),
663 (((char *)textpos
) + sizeof(struct flat_hdr
)),
664 (text_len
+ full_data
665 - sizeof(struct flat_hdr
)),
667 memmove((void *) datapos
, (void *) realdatastart
,
671 * This is used on MMU systems mainly for testing.
672 * Let's use a kernel buffer to simplify things.
674 long unz_text_len
= text_len
- sizeof(struct flat_hdr
);
675 long unz_len
= unz_text_len
+ full_data
;
676 char *unz_data
= vmalloc(unz_len
);
680 result
= decompress_exec(bprm
, sizeof(struct flat_hdr
),
681 unz_data
, unz_len
, 0);
683 (copy_to_user((void __user
*)textpos
+ sizeof(struct flat_hdr
),
684 unz_data
, unz_text_len
) ||
685 copy_to_user((void __user
*)datapos
,
686 unz_data
+ unz_text_len
, full_data
)))
691 } else if (flags
& FLAT_FLAG_GZDATA
) {
692 result
= read_code(bprm
->file
, textpos
, 0, text_len
);
693 if (!IS_ERR_VALUE(result
)) {
695 result
= decompress_exec(bprm
, text_len
, (char *) datapos
,
698 char *unz_data
= vmalloc(full_data
);
702 result
= decompress_exec(bprm
, text_len
,
703 unz_data
, full_data
, 0);
705 copy_to_user((void __user
*)datapos
,
706 unz_data
, full_data
))
713 #endif /* CONFIG_BINFMT_ZFLAT */
715 result
= read_code(bprm
->file
, textpos
, 0, text_len
);
716 if (!IS_ERR_VALUE(result
))
717 result
= read_code(bprm
->file
, datapos
,
718 ntohl(hdr
->data_start
),
721 if (IS_ERR_VALUE(result
)) {
723 pr_err("Unable to read code+data+bss, errno %d\n", ret
);
724 vm_munmap(textpos
, text_len
+ data_len
+ extra
+
725 DATA_START_OFFSET_WORDS
* sizeof(u32
));
730 start_code
= textpos
+ sizeof(struct flat_hdr
);
731 end_code
= textpos
+ text_len
;
732 text_len
-= sizeof(struct flat_hdr
); /* the real code len */
734 /* The main program needs a little extra setup in the task structure */
736 current
->mm
->start_code
= start_code
;
737 current
->mm
->end_code
= end_code
;
738 current
->mm
->start_data
= datapos
;
739 current
->mm
->end_data
= datapos
+ data_len
;
741 * set up the brk stuff, uses any slack left in data/bss/stack
742 * allocation. We put the brk after the bss (between the bss
743 * and stack) like other platforms.
744 * Userspace code relies on the stack pointer starting out at
745 * an address right at the end of a page.
747 current
->mm
->start_brk
= datapos
+ data_len
+ bss_len
;
748 current
->mm
->brk
= (current
->mm
->start_brk
+ 3) & ~3;
750 current
->mm
->context
.end_brk
= memp
+ memp_size
- stack_len
;
754 if (flags
& FLAT_FLAG_KTRACE
) {
755 pr_info("Mapping is %lx, Entry point is %x, data_start is %x\n",
756 textpos
, 0x00ffffff&ntohl(hdr
->entry
), ntohl(hdr
->data_start
));
757 pr_info("%s %s: TEXT=%lx-%lx DATA=%lx-%lx BSS=%lx-%lx\n",
758 id
? "Lib" : "Load", bprm
->filename
,
759 start_code
, end_code
, datapos
, datapos
+ data_len
,
760 datapos
+ data_len
, (datapos
+ data_len
+ bss_len
+ 3) & ~3);
763 /* Store the current module values into the global library structure */
764 libinfo
->lib_list
[id
].start_code
= start_code
;
765 libinfo
->lib_list
[id
].start_data
= datapos
;
766 libinfo
->lib_list
[id
].start_brk
= datapos
+ data_len
+ bss_len
;
767 libinfo
->lib_list
[id
].text_len
= text_len
;
768 libinfo
->lib_list
[id
].loaded
= 1;
769 libinfo
->lib_list
[id
].entry
= (0x00ffffff & ntohl(hdr
->entry
)) + textpos
;
770 libinfo
->lib_list
[id
].build_date
= ntohl(hdr
->build_date
);
773 * We just load the allocations into some temporary memory to
774 * help simplify all this mumbo jumbo
776 * We've got two different sections of relocation entries.
777 * The first is the GOT which resides at the beginning of the data segment
778 * and is terminated with a -1. This one can be relocated in place.
779 * The second is the extra relocation entries tacked after the image's
780 * data segment. These require a little more processing as the entry is
781 * really an offset into the image which contains an offset into the
784 if (flags
& FLAT_FLAG_GOTPIC
) {
785 for (rp
= (u32 __user
*)datapos
; ; rp
++) {
787 if (get_user(rp_val
, rp
))
789 if (rp_val
== 0xffffffff)
792 addr
= calc_reloc(rp_val
, libinfo
, id
, 0);
793 if (addr
== RELOC_FAILED
) {
797 if (put_user(addr
, rp
))
804 * Now run through the relocation entries.
805 * We've got to be careful here as C++ produces relocatable zero
806 * entries in the constructor and destructor tables which are then
807 * tested for being not zero (which will always occur unless we're
808 * based from address zero). This causes an endless loop as __start
809 * is at zero. The solution used is to not relocate zero addresses.
810 * This has the negative side effect of not allowing a global data
811 * reference to be statically initialised to _stext (I've moved
812 * __start to address 4 so that is okay).
814 if (rev
> OLD_FLAT_VERSION
) {
815 for (i
= 0; i
< relocs
; i
++) {
820 * Get the address of the pointer to be
821 * relocated (of course, the address has to be
824 if (get_user(tmp
, reloc
+ i
))
827 addr
= flat_get_relocate_addr(relval
);
828 rp
= (u32 __user
*)calc_reloc(addr
, libinfo
, id
, 1);
829 if (rp
== (u32 __user
*)RELOC_FAILED
) {
834 /* Get the pointer's value. */
835 ret
= flat_get_addr_from_rp(rp
, relval
, flags
, &addr
);
841 * Do the relocation. PIC relocs in the data section are
842 * already in target order
844 if ((flags
& FLAT_FLAG_GOTPIC
) == 0) {
846 * Meh, the same value can have a different
847 * byte order based on a flag..
849 addr
= ntohl((__force __be32
)addr
);
851 addr
= calc_reloc(addr
, libinfo
, id
, 0);
852 if (addr
== RELOC_FAILED
) {
857 /* Write back the relocated pointer. */
858 ret
= flat_put_addr_at_rp(rp
, addr
, relval
);
863 #ifdef CONFIG_BINFMT_FLAT_OLD
865 for (i
= 0; i
< relocs
; i
++) {
867 if (get_user(relval
, reloc
+ i
))
869 old_reloc(ntohl(relval
));
871 #endif /* CONFIG_BINFMT_FLAT_OLD */
874 flush_icache_user_range(start_code
, end_code
);
876 /* zero the BSS, BRK and stack areas */
877 if (clear_user((void __user
*)(datapos
+ data_len
), bss_len
+
878 (memp
+ memp_size
- stack_len
- /* end brk */
879 libinfo
->lib_list
[id
].start_brk
) + /* start brk */
889 /****************************************************************************/
890 #ifdef CONFIG_BINFMT_SHARED_FLAT
893 * Load a shared library into memory. The library gets its own data
894 * segment (including bss) but not argv/argc/environ.
897 static int load_flat_shared_library(int id
, struct lib_info
*libs
)
900 * This is a fake bprm struct; only the members "buf", "file" and
901 * "filename" are actually used.
903 struct linux_binprm bprm
;
908 memset(&bprm
, 0, sizeof(bprm
));
910 /* Create the file name */
911 sprintf(buf
, "/lib/lib%d.so", id
);
913 /* Open the file up */
915 bprm
.file
= open_exec(bprm
.filename
);
916 res
= PTR_ERR(bprm
.file
);
917 if (IS_ERR(bprm
.file
))
920 res
= kernel_read(bprm
.file
, bprm
.buf
, BINPRM_BUF_SIZE
, &pos
);
923 res
= load_flat_file(&bprm
, libs
, id
, NULL
);
925 allow_write_access(bprm
.file
);
931 #endif /* CONFIG_BINFMT_SHARED_FLAT */
932 /****************************************************************************/
935 * These are the functions used to load flat style executables and shared
936 * libraries. There is no binary dependent code anywhere else.
939 static int load_flat_binary(struct linux_binprm
*bprm
)
941 struct lib_info libinfo
;
942 struct pt_regs
*regs
= current_pt_regs();
943 unsigned long stack_len
= 0;
944 unsigned long start_addr
;
948 memset(&libinfo
, 0, sizeof(libinfo
));
951 * We have to add the size of our arguments to our stack size
952 * otherwise it's too easy for users to create stack overflows
953 * by passing in a huge argument list. And yes, we have to be
954 * pedantic and include space for the argv/envp array as it may have
958 stack_len
+= PAGE_SIZE
* MAX_ARG_PAGES
- bprm
->p
; /* the strings */
960 stack_len
+= (bprm
->argc
+ 1) * sizeof(char *); /* the argv array */
961 stack_len
+= (bprm
->envc
+ 1) * sizeof(char *); /* the envp array */
962 stack_len
= ALIGN(stack_len
, FLAT_STACK_ALIGN
);
964 res
= load_flat_file(bprm
, &libinfo
, 0, &stack_len
);
968 /* Update data segment pointers for all libraries */
969 for (i
= 0; i
< MAX_SHARED_LIBS
; i
++) {
970 if (!libinfo
.lib_list
[i
].loaded
)
972 for (j
= 0; j
< MAX_SHARED_LIBS
; j
++) {
973 unsigned long val
= libinfo
.lib_list
[j
].loaded
?
974 libinfo
.lib_list
[j
].start_data
: UNLOADED_LIB
;
975 unsigned long __user
*p
= (unsigned long __user
*)
976 libinfo
.lib_list
[i
].start_data
;
978 if (put_user(val
, p
))
983 set_binfmt(&flat_format
);
986 res
= setup_arg_pages(bprm
, STACK_TOP
, EXSTACK_DEFAULT
);
988 res
= create_flat_tables(bprm
, bprm
->p
);
990 /* Stash our initial stack pointer into the mm structure */
991 current
->mm
->start_stack
=
992 ((current
->mm
->context
.end_brk
+ stack_len
+ 3) & ~3) - 4;
993 pr_debug("sp=%lx\n", current
->mm
->start_stack
);
995 /* copy the arg pages onto the stack */
996 res
= transfer_args_to_stack(bprm
, ¤t
->mm
->start_stack
);
998 res
= create_flat_tables(bprm
, current
->mm
->start_stack
);
1003 /* Fake some return addresses to ensure the call chain will
1004 * initialise library in order for us. We are required to call
1005 * lib 1 first, then 2, ... and finally the main program (id 0).
1007 start_addr
= libinfo
.lib_list
[0].entry
;
1009 #ifdef CONFIG_BINFMT_SHARED_FLAT
1010 for (i
= MAX_SHARED_LIBS
-1; i
> 0; i
--) {
1011 if (libinfo
.lib_list
[i
].loaded
) {
1012 /* Push previos first to call address */
1013 unsigned long __user
*sp
;
1014 current
->mm
->start_stack
-= sizeof(unsigned long);
1015 sp
= (unsigned long __user
*)current
->mm
->start_stack
;
1016 if (put_user(start_addr
, sp
))
1018 start_addr
= libinfo
.lib_list
[i
].entry
;
1023 #ifdef FLAT_PLAT_INIT
1024 FLAT_PLAT_INIT(regs
);
1027 finalize_exec(bprm
);
1028 pr_debug("start_thread(regs=0x%p, entry=0x%lx, start_stack=0x%lx)\n",
1029 regs
, start_addr
, current
->mm
->start_stack
);
1030 start_thread(regs
, start_addr
, current
->mm
->start_stack
);
1035 /****************************************************************************/
1037 static int __init
init_flat_binfmt(void)
1039 register_binfmt(&flat_format
);
1042 core_initcall(init_flat_binfmt
);
1044 /****************************************************************************/