1 /****************************************************************************/
3 * QEMU bFLT binary loader. Based on linux/fs/binfmt_flat.c
5 * This program is free software; you can redistribute it and/or modify
6 * it under the terms of the GNU General Public License as published by
7 * the Free Software Foundation; either version 2 of the License, or
8 * (at your option) any later version.
10 * This program is distributed in the hope that it will be useful,
11 * but WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13 * GNU General Public License for more details.
15 * You should have received a copy of the GNU General Public License
16 * along with this program; if not, see <http://www.gnu.org/licenses/>.
18 * Copyright (C) 2006 CodeSourcery.
25 * linux/fs/binfmt_aout.c:
26 * Copyright (C) 1991, 1992, 1996 Linus Torvalds
27 * linux/fs/binfmt_flat.c for 2.0 kernel
32 /* ??? ZFLAT and shared library support is currently disabled. */
34 /****************************************************************************/
36 #include "qemu/osdep.h"
40 #include <target_flat.h>
45 #define DBG_FLT(...) printf(__VA_ARGS__)
50 #define RELOC_FAILED 0xff00ff01 /* Relocation incorrect somewhere */
51 #define UNLOADED_LIB 0x7ff000ff /* Placeholder for unused library */
54 abi_ulong start_code; /* Start of text segment */
55 abi_ulong start_data; /* Start of data segment */
56 abi_ulong end_data; /* Start of bss section */
57 abi_ulong start_brk; /* End of data segment */
58 abi_ulong text_len; /* Length of text segment */
59 abi_ulong entry; /* Start address for this module */
60 abi_ulong build_date; /* When this one was compiled */
61 short loaded; /* Has this library been loaded? */
64 #ifdef CONFIG_BINFMT_SHARED_FLAT
65 static int load_flat_shared_library(int id, struct lib_info *p);
70 /****************************************************************************/
72 * create_flat_tables() parses the env- and arg-strings in new user
73 * memory and creates the pointer tables from them, and puts their
74 * addresses on the "stack", returning the new stack pointer value.
77 /* Push a block of strings onto the guest stack. */
78 static abi_ulong copy_strings(abi_ulong p, int n, char **s)
83 len = strlen(s[n]) + 1;
85 memcpy_to_target(p, s[n], len);
91 static int target_pread(int fd, abi_ulong ptr, abi_ulong len,
97 buf = lock_user(VERIFY_WRITE, ptr, len, 0);
98 ret = pread(fd, buf, len, offset);
99 unlock_user(buf, ptr, len);
102 /****************************************************************************/
104 #ifdef CONFIG_BINFMT_ZFLAT
106 #include <linux/zlib.h>
108 #define LBUFSIZE 4000
111 #define ASCII_FLAG 0x01 /* bit 0 set: file probably ASCII text */
112 #define CONTINUATION 0x02 /* bit 1 set: continuation of multi-part gzip file */
113 #define EXTRA_FIELD 0x04 /* bit 2 set: extra field present */
114 #define ORIG_NAME 0x08 /* bit 3 set: original file name present */
115 #define COMMENT 0x10 /* bit 4 set: file comment present */
116 #define ENCRYPTED 0x20 /* bit 5 set: file is encrypted */
117 #define RESERVED 0xC0 /* bit 6,7: reserved */
119 static int decompress_exec(
120 struct linux_binprm *bprm,
121 unsigned long offset,
131 DBG_FLT("decompress_exec(offset=%x,buf=%x,len=%x)\n",(int)offset, (int)dst, (int)len);
133 memset(&strm, 0, sizeof(strm));
134 strm.workspace = kmalloc(zlib_inflate_workspacesize(), GFP_KERNEL);
135 if (strm.workspace == NULL) {
136 DBG_FLT("binfmt_flat: no memory for decompress workspace\n");
139 buf = kmalloc(LBUFSIZE, GFP_KERNEL);
141 DBG_FLT("binfmt_flat: no memory for read buffer\n");
146 /* Read in first chunk of data and parse gzip header. */
148 ret = bprm->file->f_op->read(bprm->file, buf, LBUFSIZE, &fpos);
156 /* Check minimum size -- gzip header */
158 DBG_FLT("binfmt_flat: file too small?\n");
162 /* Check gzip magic number */
163 if ((buf[0] != 037) || ((buf[1] != 0213) && (buf[1] != 0236))) {
164 DBG_FLT("binfmt_flat: unknown compression magic?\n");
168 /* Check gzip method */
170 DBG_FLT("binfmt_flat: unknown compression method?\n");
173 /* Check gzip flags */
174 if ((buf[3] & ENCRYPTED) || (buf[3] & CONTINUATION) ||
175 (buf[3] & RESERVED)) {
176 DBG_FLT("binfmt_flat: unknown flags?\n");
181 if (buf[3] & EXTRA_FIELD) {
182 ret += 2 + buf[10] + (buf[11] << 8);
183 if (unlikely(LBUFSIZE == ret)) {
184 DBG_FLT("binfmt_flat: buffer overflow (EXTRA)?\n");
188 if (buf[3] & ORIG_NAME) {
189 for (; ret < LBUFSIZE && (buf[ret] != 0); ret++)
191 if (unlikely(LBUFSIZE == ret)) {
192 DBG_FLT("binfmt_flat: buffer overflow (ORIG_NAME)?\n");
196 if (buf[3] & COMMENT) {
197 for (; ret < LBUFSIZE && (buf[ret] != 0); ret++)
199 if (unlikely(LBUFSIZE == ret)) {
200 DBG_FLT("binfmt_flat: buffer overflow (COMMENT)?\n");
206 strm.avail_in -= ret;
209 strm.avail_out = len;
212 if (zlib_inflateInit2(&strm, -MAX_WBITS) != Z_OK) {
213 DBG_FLT("binfmt_flat: zlib init failed?\n");
217 while ((ret = zlib_inflate(&strm, Z_NO_FLUSH)) == Z_OK) {
218 ret = bprm->file->f_op->read(bprm->file, buf, LBUFSIZE, &fpos);
221 if (ret >= (unsigned long) -4096)
231 DBG_FLT("binfmt_flat: decompression failed (%d), %s\n",
238 zlib_inflateEnd(&strm);
242 kfree(strm.workspace);
247 #endif /* CONFIG_BINFMT_ZFLAT */
249 /****************************************************************************/
252 calc_reloc(abi_ulong r, struct lib_info *p, int curid, int internalp)
257 abi_ulong start_data;
259 abi_ulong start_code;
261 #ifdef CONFIG_BINFMT_SHARED_FLAT
262 #error needs checking
264 id = curid; /* Relocs of 0 are always self referring */
266 id = (r >> 24) & 0xff; /* Find ID for this reloc */
267 r &= 0x00ffffff; /* Trim ID off here */
269 if (id >= MAX_SHARED_LIBS) {
270 fprintf(stderr, "BINFMT_FLAT: reference 0x%x to shared library %d\n",
276 fprintf(stderr, "BINFMT_FLAT: reloc address 0x%x not "
277 "in same module (%d != %d)\n",
278 (unsigned) r, curid, id);
280 } else if ( ! p[id].loaded &&
281 load_flat_shared_library(id, p) > (unsigned long) -4096) {
282 fprintf(stderr, "BINFMT_FLAT: failed to load library %d\n", id);
285 /* Check versioning information (i.e. time stamps) */
286 if (p[id].build_date && p[curid].build_date
287 && p[curid].build_date < p[id].build_date) {
288 fprintf(stderr, "BINFMT_FLAT: library %d is younger than %d\n",
297 start_brk = p[id].start_brk;
298 start_data = p[id].start_data;
299 start_code = p[id].start_code;
300 text_len = p[id].text_len;
302 if (!flat_reloc_valid(r, start_brk - start_data + text_len)) {
303 fprintf(stderr, "BINFMT_FLAT: reloc outside program 0x%x "
305 (int) r,(int)(start_brk-start_code),(int)text_len);
309 if (r < text_len) /* In text segment */
310 addr = r + start_code;
311 else /* In data segment */
312 addr = r - text_len + start_data;
314 /* Range checked already above so doing the range tests is redundant...*/
322 /****************************************************************************/
324 /* ??? This does not handle endianness correctly. */
325 static void old_reloc(struct lib_info *libinfo, uint32_t rl)
328 const char *segment[] = { "TEXT", "DATA", "BSS", "*UNKNOWN*" };
334 offset = rl & 0x3fffffff;
335 reloc_type = rl >> 30;
336 /* ??? How to handle this? */
337 #if defined(CONFIG_COLDFIRE)
338 ptr = (uint32_t *) ((unsigned long) libinfo->start_code + offset);
340 ptr = (uint32_t *) ((unsigned long) libinfo->start_data + offset);
344 fprintf(stderr, "Relocation of variable at DATASEG+%x "
345 "(address %p, currently %x) into segment %s\n",
346 offset, ptr, (int)*ptr, segment[reloc_type]);
349 switch (reloc_type) {
350 case OLD_FLAT_RELOC_TYPE_TEXT:
351 *ptr += libinfo->start_code;
353 case OLD_FLAT_RELOC_TYPE_DATA:
354 *ptr += libinfo->start_data;
356 case OLD_FLAT_RELOC_TYPE_BSS:
357 *ptr += libinfo->end_data;
360 fprintf(stderr, "BINFMT_FLAT: Unknown relocation type=%x\n",
364 DBG_FLT("Relocation became %x\n", (int)*ptr);
367 /****************************************************************************/
369 static int load_flat_file(struct linux_binprm * bprm,
370 struct lib_info *libinfo, int id, abi_ulong *extra_stack)
372 struct flat_hdr * hdr;
373 abi_ulong textpos = 0, datapos = 0;
375 abi_ulong realdatastart = 0;
376 abi_ulong text_len, data_len, bss_len, stack_len, flags;
378 abi_ulong reloc = 0, rp;
379 int i, rev, relocs = 0;
381 abi_ulong start_code;
384 hdr = ((struct flat_hdr *) bprm->buf); /* exec-header */
386 text_len = ntohl(hdr->data_start);
387 data_len = ntohl(hdr->data_end) - ntohl(hdr->data_start);
388 bss_len = ntohl(hdr->bss_end) - ntohl(hdr->data_end);
389 stack_len = ntohl(hdr->stack_size);
391 stack_len += *extra_stack;
392 *extra_stack = stack_len;
394 relocs = ntohl(hdr->reloc_count);
395 flags = ntohl(hdr->flags);
396 rev = ntohl(hdr->rev);
398 DBG_FLT("BINFMT_FLAT: Loading file: %s\n", bprm->filename);
400 if (rev != FLAT_VERSION && rev != OLD_FLAT_VERSION) {
401 fprintf(stderr, "BINFMT_FLAT: bad magic/rev (0x%x, need 0x%x)\n",
402 rev, (int) FLAT_VERSION);
406 /* Don't allow old format executables to use shared libraries */
407 if (rev == OLD_FLAT_VERSION && id != 0) {
408 fprintf(stderr, "BINFMT_FLAT: shared libraries are not available\n");
413 * fix up the flags for the older format, there were all kinds
414 * of endian hacks, this only works for the simple cases
416 if (rev == OLD_FLAT_VERSION && flat_old_ram_flag(flags))
417 flags = FLAT_FLAG_RAM;
419 #ifndef CONFIG_BINFMT_ZFLAT
420 if (flags & (FLAT_FLAG_GZIP|FLAT_FLAG_GZDATA)) {
421 fprintf(stderr, "Support for ZFLAT executables is not enabled\n");
427 * calculate the extra space we need to map in
429 extra = relocs * sizeof(abi_ulong);
430 if (extra < bss_len + stack_len)
431 extra = bss_len + stack_len;
433 /* Add space for library base pointers. Make sure this does not
434 misalign the doesn't misalign the data segment. */
435 indx_len = MAX_SHARED_LIBS * sizeof(abi_ulong);
436 indx_len = (indx_len + 15) & ~(abi_ulong)15;
439 * there are a couple of cases here, the separate code/data
440 * case, and then the fully copied to RAM case which lumps
443 if ((flags & (FLAT_FLAG_RAM|FLAT_FLAG_GZIP)) == 0) {
445 * this should give us a ROM ptr, but if it doesn't we don't
448 DBG_FLT("BINFMT_FLAT: ROM mapping of file (we hope)\n");
450 textpos = target_mmap(0, text_len, PROT_READ|PROT_EXEC,
451 MAP_PRIVATE, bprm->fd, 0);
453 fprintf(stderr, "Unable to mmap process text\n");
457 realdatastart = target_mmap(0, data_len + extra + indx_len,
458 PROT_READ|PROT_WRITE|PROT_EXEC,
459 MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
461 if (realdatastart == -1) {
462 fprintf(stderr, "Unable to allocate RAM for process data\n");
463 return realdatastart;
465 datapos = realdatastart + indx_len;
467 DBG_FLT("BINFMT_FLAT: Allocated data+bss+stack (%d bytes): %x\n",
468 (int)(data_len + bss_len + stack_len), (int)datapos);
470 fpos = ntohl(hdr->data_start);
471 #ifdef CONFIG_BINFMT_ZFLAT
472 if (flags & FLAT_FLAG_GZDATA) {
473 result = decompress_exec(bprm, fpos, (char *) datapos,
474 data_len + (relocs * sizeof(abi_ulong)))
478 result = target_pread(bprm->fd, datapos,
479 data_len + (relocs * sizeof(abi_ulong)),
483 fprintf(stderr, "Unable to read data+bss\n");
487 reloc = datapos + (ntohl(hdr->reloc_start) - text_len);
491 textpos = target_mmap(0, text_len + data_len + extra + indx_len,
492 PROT_READ | PROT_EXEC | PROT_WRITE,
493 MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
494 if (textpos == -1 ) {
495 fprintf(stderr, "Unable to allocate RAM for process text/data\n");
499 realdatastart = textpos + ntohl(hdr->data_start);
500 datapos = realdatastart + indx_len;
501 reloc = (textpos + ntohl(hdr->reloc_start) + indx_len);
503 #ifdef CONFIG_BINFMT_ZFLAT
504 #error code needs checking
506 * load it all in and treat it like a RAM load from now on
508 if (flags & FLAT_FLAG_GZIP) {
509 result = decompress_exec(bprm, sizeof (struct flat_hdr),
510 (((char *) textpos) + sizeof (struct flat_hdr)),
511 (text_len + data_len + (relocs * sizeof(unsigned long))
512 - sizeof (struct flat_hdr)),
514 memmove((void *) datapos, (void *) realdatastart,
515 data_len + (relocs * sizeof(unsigned long)));
516 } else if (flags & FLAT_FLAG_GZDATA) {
518 result = bprm->file->f_op->read(bprm->file,
519 (char *) textpos, text_len, &fpos);
520 if (result < (unsigned long) -4096)
521 result = decompress_exec(bprm, text_len, (char *) datapos,
522 data_len + (relocs * sizeof(unsigned long)), 0);
527 result = target_pread(bprm->fd, textpos,
530 result = target_pread(bprm->fd, datapos,
531 data_len + (relocs * sizeof(abi_ulong)),
532 ntohl(hdr->data_start));
536 fprintf(stderr, "Unable to read code+data+bss\n");
541 DBG_FLT("Mapping is 0x%x, Entry point is 0x%x, data_start is 0x%x\n",
542 (int)textpos, 0x00ffffff&ntohl(hdr->entry),
543 ntohl(hdr->data_start));
545 /* The main program needs a little extra setup in the task structure */
546 start_code = textpos + sizeof (struct flat_hdr);
548 DBG_FLT("%s %s: TEXT=%x-%x DATA=%x-%x BSS=%x-%x\n",
549 id ? "Lib" : "Load", bprm->filename,
550 (int) start_code, (int) (textpos + text_len),
552 (int) (datapos + data_len),
553 (int) (datapos + data_len),
554 (int) (((datapos + data_len + bss_len) + 3) & ~3));
556 text_len -= sizeof(struct flat_hdr); /* the real code len */
558 /* Store the current module values into the global library structure */
559 libinfo[id].start_code = start_code;
560 libinfo[id].start_data = datapos;
561 libinfo[id].end_data = datapos + data_len;
562 libinfo[id].start_brk = datapos + data_len + bss_len;
563 libinfo[id].text_len = text_len;
564 libinfo[id].loaded = 1;
565 libinfo[id].entry = (0x00ffffff & ntohl(hdr->entry)) + textpos;
566 libinfo[id].build_date = ntohl(hdr->build_date);
569 * We just load the allocations into some temporary memory to
570 * help simplify all this mumbo jumbo
572 * We've got two different sections of relocation entries.
573 * The first is the GOT which resides at the beginning of the data segment
574 * and is terminated with a -1. This one can be relocated in place.
575 * The second is the extra relocation entries tacked after the image's
576 * data segment. These require a little more processing as the entry is
577 * really an offset into the image which contains an offset into the
580 if (flags & FLAT_FLAG_GOTPIC) {
584 if (get_user_ual(addr, rp))
589 addr = calc_reloc(addr, libinfo, id, 0);
590 if (addr == RELOC_FAILED)
592 if (put_user_ual(addr, rp))
595 rp += sizeof(abi_ulong);
600 * Now run through the relocation entries.
601 * We've got to be careful here as C++ produces relocatable zero
602 * entries in the constructor and destructor tables which are then
603 * tested for being not zero (which will always occur unless we're
604 * based from address zero). This causes an endless loop as __start
605 * is at zero. The solution used is to not relocate zero addresses.
606 * This has the negative side effect of not allowing a global data
607 * reference to be statically initialised to _stext (I've moved
608 * __start to address 4 so that is okay).
610 if (rev > OLD_FLAT_VERSION) {
611 abi_ulong persistent = 0;
612 for (i = 0; i < relocs; i++) {
613 abi_ulong addr, relval;
615 /* Get the address of the pointer to be
616 relocated (of course, the address has to be
618 if (get_user_ual(relval, reloc + i * sizeof(abi_ulong)))
620 relval = ntohl(relval);
621 if (flat_set_persistent(relval, &persistent))
623 addr = flat_get_relocate_addr(relval);
624 rp = calc_reloc(addr, libinfo, id, 1);
625 if (rp == RELOC_FAILED)
628 /* Get the pointer's value. */
629 if (get_user_ual(addr, rp))
631 addr = flat_get_addr_from_rp(addr, relval, flags, &persistent);
634 * Do the relocation. PIC relocs in the data section are
635 * already in target order
637 if ((flags & FLAT_FLAG_GOTPIC) == 0)
639 addr = calc_reloc(addr, libinfo, id, 0);
640 if (addr == RELOC_FAILED)
643 /* Write back the relocated pointer. */
644 if (flat_put_addr_at_rp(rp, addr, relval))
649 for (i = 0; i < relocs; i++) {
651 if (get_user_ual(relval, reloc + i * sizeof(abi_ulong)))
653 old_reloc(&libinfo[0], relval);
658 memset(g2h(datapos + data_len), 0, bss_len);
664 /****************************************************************************/
665 #ifdef CONFIG_BINFMT_SHARED_FLAT
668 * Load a shared library into memory. The library gets its own data
669 * segment (including bss) but not argv/argc/environ.
672 static int load_flat_shared_library(int id, struct lib_info *libs)
674 struct linux_binprm bprm;
678 /* Create the file name */
679 sprintf(buf, "/lib/lib%d.so", id);
681 /* Open the file up */
683 bprm.file = open_exec(bprm.filename);
684 res = PTR_ERR(bprm.file);
685 if (IS_ERR(bprm.file))
688 res = prepare_binprm(&bprm);
690 if (res <= (unsigned long)-4096)
691 res = load_flat_file(&bprm, libs, id, NULL);
693 allow_write_access(bprm.file);
700 #endif /* CONFIG_BINFMT_SHARED_FLAT */
702 int load_flt_binary(struct linux_binprm *bprm, struct image_info *info)
704 struct lib_info libinfo[MAX_SHARED_LIBS];
707 abi_ulong start_addr;
712 memset(libinfo, 0, sizeof(libinfo));
714 * We have to add the size of our arguments to our stack size
715 * otherwise it's too easy for users to create stack overflows
716 * by passing in a huge argument list. And yes, we have to be
717 * pedantic and include space for the argv/envp array as it may have
721 for (i = 0; i < bprm->argc; ++i) {
722 /* the argv strings */
723 stack_len += strlen(bprm->argv[i]);
725 for (i = 0; i < bprm->envc; ++i) {
726 /* the envp strings */
727 stack_len += strlen(bprm->envp[i]);
729 stack_len += (bprm->argc + 1) * 4; /* the argv array */
730 stack_len += (bprm->envc + 1) * 4; /* the envp array */
733 res = load_flat_file(bprm, libinfo, 0, &stack_len);
734 if (res > (unsigned long)-4096)
737 /* Update data segment pointers for all libraries */
738 for (i=0; i<MAX_SHARED_LIBS; i++) {
739 if (libinfo[i].loaded) {
741 p = libinfo[i].start_data;
742 for (j=0; j<MAX_SHARED_LIBS; j++) {
744 /* FIXME - handle put_user() failures */
745 if (put_user_ual(libinfo[j].loaded
746 ? libinfo[j].start_data
754 p = ((libinfo[0].start_brk + stack_len + 3) & ~3) - 4;
755 DBG_FLT("p=%x\n", (int)p);
757 /* Copy argv/envp. */
758 p = copy_strings(p, bprm->envc, bprm->envp);
759 p = copy_strings(p, bprm->argc, bprm->argv);
761 sp = p & ~(abi_ulong)(sizeof(abi_ulong) - 1);
762 /* Enforce final stack alignment of 16 bytes. This is sufficient
763 for all current targets, and excess alignment is harmless. */
764 stack_len = bprm->envc + bprm->argc + 2;
765 stack_len += 3; /* argc, arvg, argp */
766 stack_len *= sizeof(abi_ulong);
767 if ((sp + stack_len) & 15)
768 sp -= 16 - ((sp + stack_len) & 15);
769 sp = loader_build_argptr(bprm->envc, bprm->argc, sp, p,
770 flat_argvp_envp_on_stack());
772 /* Fake some return addresses to ensure the call chain will
773 * initialise library in order for us. We are required to call
774 * lib 1 first, then 2, ... and finally the main program (id 0).
776 start_addr = libinfo[0].entry;
778 #ifdef CONFIG_BINFMT_SHARED_FLAT
780 for (i = MAX_SHARED_LIBS-1; i>0; i--) {
781 if (libinfo[i].loaded) {
782 /* Push previos first to call address */
784 if (put_user_ual(start_addr, sp))
786 start_addr = libinfo[i].entry;
791 /* Stash our initial stack pointer into the mm structure */
792 info->start_code = libinfo[0].start_code;
793 info->end_code = libinfo[0].start_code = libinfo[0].text_len;
794 info->start_data = libinfo[0].start_data;
795 info->end_data = libinfo[0].end_data;
796 info->start_brk = libinfo[0].start_brk;
797 info->start_stack = sp;
798 info->stack_limit = libinfo[0].start_brk;
799 info->entry = start_addr;
800 info->code_offset = info->start_code;
801 info->data_offset = info->start_data - libinfo[0].text_len;
803 DBG_FLT("start_thread(entry=0x%x, start_stack=0x%x)\n",
804 (int)info->entry, (int)info->start_stack);