xref: /illumos-kvm-cmd/linux-user/flatload.c (revision 68396ea9)
1 /****************************************************************************/
2 /*
3  *  QEMU bFLT binary loader.  Based on linux/fs/binfmt_flat.c
4  *
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.
9  *
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.
14  *
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/>.
17  *
18  *      Copyright (C) 2006 CodeSourcery.
19  *	Copyright (C) 2000-2003 David McCullough <davidm@snapgear.com>
20  *	Copyright (C) 2002 Greg Ungerer <gerg@snapgear.com>
21  *	Copyright (C) 2002 SnapGear, by Paul Dale <pauli@snapgear.com>
22  *	Copyright (C) 2000, 2001 Lineo, by David McCullough <davidm@lineo.com>
23  *  based heavily on:
24  *
25  *  linux/fs/binfmt_aout.c:
26  *      Copyright (C) 1991, 1992, 1996  Linus Torvalds
27  *  linux/fs/binfmt_flat.c for 2.0 kernel
28  *	    Copyright (C) 1998  Kenneth Albanowski <kjahds@kjahds.com>
29  *	JAN/99 -- coded full program relocation (gerg@snapgear.com)
30  */
31 
32 /* ??? ZFLAT and shared library support is currently disabled.  */
33 
34 /****************************************************************************/
35 
36 #include <stdio.h>
37 #include <stdlib.h>
38 #include <errno.h>
39 #include <sys/mman.h>
40 #include <unistd.h>
41 
42 #include "qemu.h"
43 #include "flat.h"
44 
45 //#define DEBUG
46 
47 #ifdef DEBUG
48 #define	DBG_FLT(...)	printf(__VA_ARGS__)
49 #else
50 #define	DBG_FLT(...)
51 #endif
52 
53 #define flat_reloc_valid(reloc, size)             ((reloc) <= (size))
54 #define flat_old_ram_flag(flag)                   (flag)
55 #ifdef TARGET_WORDS_BIGENDIAN
56 #define flat_get_relocate_addr(relval)            (relval)
57 #else
58 #define flat_get_relocate_addr(relval)            bswap32(relval)
59 #endif
60 
61 #define RELOC_FAILED 0xff00ff01		/* Relocation incorrect somewhere */
62 #define UNLOADED_LIB 0x7ff000ff		/* Placeholder for unused library */
63 
64 struct lib_info {
65     abi_ulong start_code;       /* Start of text segment */
66     abi_ulong start_data;       /* Start of data segment */
67     abi_ulong end_data;         /* Start of bss section */
68     abi_ulong start_brk;        /* End of data segment */
69     abi_ulong text_len;	        /* Length of text segment */
70     abi_ulong entry;	        /* Start address for this module */
71     abi_ulong build_date;       /* When this one was compiled */
72     short loaded;		/* Has this library been loaded? */
73 };
74 
75 #ifdef CONFIG_BINFMT_SHARED_FLAT
76 static int load_flat_shared_library(int id, struct lib_info *p);
77 #endif
78 
79 struct linux_binprm;
80 
81 #define ntohl(x) be32_to_cpu(x)
82 
83 /****************************************************************************/
84 /*
85  * create_flat_tables() parses the env- and arg-strings in new user
86  * memory and creates the pointer tables from them, and puts their
87  * addresses on the "stack", returning the new stack pointer value.
88  */
89 
90 /* Push a block of strings onto the guest stack.  */
copy_strings(abi_ulong p,int n,char ** s)91 static abi_ulong copy_strings(abi_ulong p, int n, char **s)
92 {
93     int len;
94 
95     while (n-- > 0) {
96         len = strlen(s[n]) + 1;
97         p -= len;
98         memcpy_to_target(p, s[n], len);
99     }
100 
101     return p;
102 }
103 
target_pread(int fd,abi_ulong ptr,abi_ulong len,abi_ulong offset)104 static int target_pread(int fd, abi_ulong ptr, abi_ulong len,
105                         abi_ulong offset)
106 {
107     void *buf;
108     int ret;
109 
110     buf = lock_user(VERIFY_WRITE, ptr, len, 0);
111     ret = pread(fd, buf, len, offset);
112     unlock_user(buf, ptr, len);
113     return ret;
114 }
115 /****************************************************************************/
116 
117 #ifdef CONFIG_BINFMT_ZFLAT
118 
119 #include <linux/zlib.h>
120 
121 #define LBUFSIZE	4000
122 
123 /* gzip flag byte */
124 #define ASCII_FLAG   0x01 /* bit 0 set: file probably ASCII text */
125 #define CONTINUATION 0x02 /* bit 1 set: continuation of multi-part gzip file */
126 #define EXTRA_FIELD  0x04 /* bit 2 set: extra field present */
127 #define ORIG_NAME    0x08 /* bit 3 set: original file name present */
128 #define COMMENT      0x10 /* bit 4 set: file comment present */
129 #define ENCRYPTED    0x20 /* bit 5 set: file is encrypted */
130 #define RESERVED     0xC0 /* bit 6,7:   reserved */
131 
decompress_exec(struct linux_binprm * bprm,unsigned long offset,char * dst,long len,int fd)132 static int decompress_exec(
133 	struct linux_binprm *bprm,
134 	unsigned long offset,
135 	char *dst,
136 	long len,
137 	int fd)
138 {
139 	unsigned char *buf;
140 	z_stream strm;
141 	loff_t fpos;
142 	int ret, retval;
143 
144 	DBG_FLT("decompress_exec(offset=%x,buf=%x,len=%x)\n",(int)offset, (int)dst, (int)len);
145 
146 	memset(&strm, 0, sizeof(strm));
147 	strm.workspace = kmalloc(zlib_inflate_workspacesize(), GFP_KERNEL);
148 	if (strm.workspace == NULL) {
149 		DBG_FLT("binfmt_flat: no memory for decompress workspace\n");
150 		return -ENOMEM;
151 	}
152 	buf = kmalloc(LBUFSIZE, GFP_KERNEL);
153 	if (buf == NULL) {
154 		DBG_FLT("binfmt_flat: no memory for read buffer\n");
155 		retval = -ENOMEM;
156 		goto out_free;
157 	}
158 
159 	/* Read in first chunk of data and parse gzip header. */
160 	fpos = offset;
161 	ret = bprm->file->f_op->read(bprm->file, buf, LBUFSIZE, &fpos);
162 
163 	strm.next_in = buf;
164 	strm.avail_in = ret;
165 	strm.total_in = 0;
166 
167 	retval = -ENOEXEC;
168 
169 	/* Check minimum size -- gzip header */
170 	if (ret < 10) {
171 		DBG_FLT("binfmt_flat: file too small?\n");
172 		goto out_free_buf;
173 	}
174 
175 	/* Check gzip magic number */
176 	if ((buf[0] != 037) || ((buf[1] != 0213) && (buf[1] != 0236))) {
177 		DBG_FLT("binfmt_flat: unknown compression magic?\n");
178 		goto out_free_buf;
179 	}
180 
181 	/* Check gzip method */
182 	if (buf[2] != 8) {
183 		DBG_FLT("binfmt_flat: unknown compression method?\n");
184 		goto out_free_buf;
185 	}
186 	/* Check gzip flags */
187 	if ((buf[3] & ENCRYPTED) || (buf[3] & CONTINUATION) ||
188 	    (buf[3] & RESERVED)) {
189 		DBG_FLT("binfmt_flat: unknown flags?\n");
190 		goto out_free_buf;
191 	}
192 
193 	ret = 10;
194 	if (buf[3] & EXTRA_FIELD) {
195 		ret += 2 + buf[10] + (buf[11] << 8);
196 		if (unlikely(LBUFSIZE == ret)) {
197 			DBG_FLT("binfmt_flat: buffer overflow (EXTRA)?\n");
198 			goto out_free_buf;
199 		}
200 	}
201 	if (buf[3] & ORIG_NAME) {
202 		for (; ret < LBUFSIZE && (buf[ret] != 0); ret++)
203 			;
204 		if (unlikely(LBUFSIZE == ret)) {
205 			DBG_FLT("binfmt_flat: buffer overflow (ORIG_NAME)?\n");
206 			goto out_free_buf;
207 		}
208 	}
209 	if (buf[3] & COMMENT) {
210 		for (;  ret < LBUFSIZE && (buf[ret] != 0); ret++)
211 			;
212 		if (unlikely(LBUFSIZE == ret)) {
213 			DBG_FLT("binfmt_flat: buffer overflow (COMMENT)?\n");
214 			goto out_free_buf;
215 		}
216 	}
217 
218 	strm.next_in += ret;
219 	strm.avail_in -= ret;
220 
221 	strm.next_out = dst;
222 	strm.avail_out = len;
223 	strm.total_out = 0;
224 
225 	if (zlib_inflateInit2(&strm, -MAX_WBITS) != Z_OK) {
226 		DBG_FLT("binfmt_flat: zlib init failed?\n");
227 		goto out_free_buf;
228 	}
229 
230 	while ((ret = zlib_inflate(&strm, Z_NO_FLUSH)) == Z_OK) {
231 		ret = bprm->file->f_op->read(bprm->file, buf, LBUFSIZE, &fpos);
232 		if (ret <= 0)
233 			break;
234 		if (ret >= (unsigned long) -4096)
235 			break;
236 		len -= ret;
237 
238 		strm.next_in = buf;
239 		strm.avail_in = ret;
240 		strm.total_in = 0;
241 	}
242 
243 	if (ret < 0) {
244 		DBG_FLT("binfmt_flat: decompression failed (%d), %s\n",
245 			ret, strm.msg);
246 		goto out_zlib;
247 	}
248 
249 	retval = 0;
250 out_zlib:
251 	zlib_inflateEnd(&strm);
252 out_free_buf:
253 	kfree(buf);
254 out_free:
255 	kfree(strm.workspace);
256 out:
257 	return retval;
258 }
259 
260 #endif /* CONFIG_BINFMT_ZFLAT */
261 
262 /****************************************************************************/
263 
264 static abi_ulong
calc_reloc(abi_ulong r,struct lib_info * p,int curid,int internalp)265 calc_reloc(abi_ulong r, struct lib_info *p, int curid, int internalp)
266 {
267     abi_ulong addr;
268     int id;
269     abi_ulong start_brk;
270     abi_ulong start_data;
271     abi_ulong text_len;
272     abi_ulong start_code;
273 
274 #ifdef CONFIG_BINFMT_SHARED_FLAT
275 #error needs checking
276     if (r == 0)
277         id = curid;	/* Relocs of 0 are always self referring */
278     else {
279         id = (r >> 24) & 0xff;	/* Find ID for this reloc */
280         r &= 0x00ffffff;	/* Trim ID off here */
281     }
282     if (id >= MAX_SHARED_LIBS) {
283         fprintf(stderr, "BINFMT_FLAT: reference 0x%x to shared library %d\n",
284                 (unsigned) r, id);
285         goto failed;
286     }
287     if (curid != id) {
288         if (internalp) {
289             fprintf(stderr, "BINFMT_FLAT: reloc address 0x%x not "
290                     "in same module (%d != %d)\n",
291                     (unsigned) r, curid, id);
292             goto failed;
293         } else if ( ! p[id].loaded &&
294                     load_flat_shared_library(id, p) > (unsigned long) -4096) {
295             fprintf(stderr, "BINFMT_FLAT: failed to load library %d\n", id);
296             goto failed;
297         }
298         /* Check versioning information (i.e. time stamps) */
299         if (p[id].build_date && p[curid].build_date
300             && p[curid].build_date < p[id].build_date) {
301             fprintf(stderr, "BINFMT_FLAT: library %d is younger than %d\n",
302                     id, curid);
303             goto failed;
304         }
305     }
306 #else
307     id = 0;
308 #endif
309 
310     start_brk = p[id].start_brk;
311     start_data = p[id].start_data;
312     start_code = p[id].start_code;
313     text_len = p[id].text_len;
314 
315     if (!flat_reloc_valid(r, start_brk - start_data + text_len)) {
316         fprintf(stderr, "BINFMT_FLAT: reloc outside program 0x%x "
317                 "(0 - 0x%x/0x%x)\n",
318                (int) r,(int)(start_brk-start_code),(int)text_len);
319         goto failed;
320     }
321 
322     if (r < text_len)			/* In text segment */
323         addr = r + start_code;
324     else					/* In data segment */
325         addr = r - text_len + start_data;
326 
327     /* Range checked already above so doing the range tests is redundant...*/
328     return(addr);
329 
330 failed:
331     abort();
332     return RELOC_FAILED;
333 }
334 
335 /****************************************************************************/
336 
337 /* ??? This does not handle endianness correctly.  */
old_reloc(struct lib_info * libinfo,uint32_t rl)338 static void old_reloc(struct lib_info *libinfo, uint32_t rl)
339 {
340 #ifdef DEBUG
341 	const char *segment[] = { "TEXT", "DATA", "BSS", "*UNKNOWN*" };
342 #endif
343 	uint32_t *ptr;
344         uint32_t offset;
345         int reloc_type;
346 
347         offset = rl & 0x3fffffff;
348         reloc_type = rl >> 30;
349         /* ??? How to handle this?  */
350 #if defined(CONFIG_COLDFIRE)
351 	ptr = (uint32_t *) ((unsigned long) libinfo->start_code + offset);
352 #else
353 	ptr = (uint32_t *) ((unsigned long) libinfo->start_data + offset);
354 #endif
355 
356 #ifdef DEBUG
357 	fprintf(stderr, "Relocation of variable at DATASEG+%x "
358 		"(address %p, currently %x) into segment %s\n",
359 		offset, ptr, (int)*ptr, segment[reloc_type]);
360 #endif
361 
362 	switch (reloc_type) {
363 	case OLD_FLAT_RELOC_TYPE_TEXT:
364 		*ptr += libinfo->start_code;
365 		break;
366 	case OLD_FLAT_RELOC_TYPE_DATA:
367 		*ptr += libinfo->start_data;
368 		break;
369 	case OLD_FLAT_RELOC_TYPE_BSS:
370 		*ptr += libinfo->end_data;
371 		break;
372 	default:
373 		fprintf(stderr, "BINFMT_FLAT: Unknown relocation type=%x\n",
374                         reloc_type);
375 		break;
376 	}
377 	DBG_FLT("Relocation became %x\n", (int)*ptr);
378 }
379 
380 /****************************************************************************/
381 
load_flat_file(struct linux_binprm * bprm,struct lib_info * libinfo,int id,abi_ulong * extra_stack)382 static int load_flat_file(struct linux_binprm * bprm,
383 		struct lib_info *libinfo, int id, abi_ulong *extra_stack)
384 {
385     struct flat_hdr * hdr;
386     abi_ulong textpos = 0, datapos = 0;
387     abi_long result;
388     abi_ulong realdatastart = 0;
389     abi_ulong text_len, data_len, bss_len, stack_len, flags;
390     abi_ulong memp = 0; /* for finding the brk area */
391     abi_ulong extra;
392     abi_ulong reloc = 0, rp;
393     int i, rev, relocs = 0;
394     abi_ulong fpos;
395     abi_ulong start_code, end_code;
396     abi_ulong indx_len;
397 
398     hdr = ((struct flat_hdr *) bprm->buf);		/* exec-header */
399 
400     text_len  = ntohl(hdr->data_start);
401     data_len  = ntohl(hdr->data_end) - ntohl(hdr->data_start);
402     bss_len   = ntohl(hdr->bss_end) - ntohl(hdr->data_end);
403     stack_len = ntohl(hdr->stack_size);
404     if (extra_stack) {
405         stack_len += *extra_stack;
406         *extra_stack = stack_len;
407     }
408     relocs    = ntohl(hdr->reloc_count);
409     flags     = ntohl(hdr->flags);
410     rev       = ntohl(hdr->rev);
411 
412     DBG_FLT("BINFMT_FLAT: Loading file: %s\n", bprm->filename);
413 
414     if (rev != FLAT_VERSION && rev != OLD_FLAT_VERSION) {
415         fprintf(stderr, "BINFMT_FLAT: bad magic/rev (0x%x, need 0x%x)\n",
416                 rev, (int) FLAT_VERSION);
417         return -ENOEXEC;
418     }
419 
420     /* Don't allow old format executables to use shared libraries */
421     if (rev == OLD_FLAT_VERSION && id != 0) {
422         fprintf(stderr, "BINFMT_FLAT: shared libraries are not available\n");
423         return -ENOEXEC;
424     }
425 
426     /*
427      * fix up the flags for the older format,  there were all kinds
428      * of endian hacks,  this only works for the simple cases
429      */
430     if (rev == OLD_FLAT_VERSION && flat_old_ram_flag(flags))
431         flags = FLAT_FLAG_RAM;
432 
433 #ifndef CONFIG_BINFMT_ZFLAT
434     if (flags & (FLAT_FLAG_GZIP|FLAT_FLAG_GZDATA)) {
435         fprintf(stderr, "Support for ZFLAT executables is not enabled\n");
436         return -ENOEXEC;
437     }
438 #endif
439 
440     /*
441      * calculate the extra space we need to map in
442      */
443     extra = relocs * sizeof(abi_ulong);
444     if (extra < bss_len + stack_len)
445         extra = bss_len + stack_len;
446 
447     /* Add space for library base pointers.  Make sure this does not
448        misalign the  doesn't misalign the data segment.  */
449     indx_len = MAX_SHARED_LIBS * sizeof(abi_ulong);
450     indx_len = (indx_len + 15) & ~(abi_ulong)15;
451 
452     /*
453      * there are a couple of cases here,  the separate code/data
454      * case,  and then the fully copied to RAM case which lumps
455      * it all together.
456      */
457     if ((flags & (FLAT_FLAG_RAM|FLAT_FLAG_GZIP)) == 0) {
458         /*
459          * this should give us a ROM ptr,  but if it doesn't we don't
460          * really care
461          */
462         DBG_FLT("BINFMT_FLAT: ROM mapping of file (we hope)\n");
463 
464         textpos = target_mmap(0, text_len, PROT_READ|PROT_EXEC,
465                               MAP_PRIVATE, bprm->fd, 0);
466         if (textpos == -1) {
467             fprintf(stderr, "Unable to mmap process text\n");
468             return -1;
469         }
470 
471         realdatastart = target_mmap(0, data_len + extra + indx_len,
472                                     PROT_READ|PROT_WRITE|PROT_EXEC,
473                                     MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
474 
475         if (realdatastart == -1) {
476             fprintf(stderr, "Unable to allocate RAM for process data\n");
477             return realdatastart;
478         }
479         datapos = realdatastart + indx_len;
480 
481         DBG_FLT("BINFMT_FLAT: Allocated data+bss+stack (%d bytes): %x\n",
482                         (int)(data_len + bss_len + stack_len), (int)datapos);
483 
484         fpos = ntohl(hdr->data_start);
485 #ifdef CONFIG_BINFMT_ZFLAT
486         if (flags & FLAT_FLAG_GZDATA) {
487             result = decompress_exec(bprm, fpos, (char *) datapos,
488                                      data_len + (relocs * sizeof(abi_ulong)))
489         } else
490 #endif
491         {
492             result = target_pread(bprm->fd, datapos,
493                                   data_len + (relocs * sizeof(abi_ulong)),
494                                   fpos);
495         }
496         if (result < 0) {
497             fprintf(stderr, "Unable to read data+bss\n");
498             return result;
499         }
500 
501         reloc = datapos + (ntohl(hdr->reloc_start) - text_len);
502         memp = realdatastart;
503 
504     } else {
505 
506         textpos = target_mmap(0, text_len + data_len + extra + indx_len,
507                               PROT_READ | PROT_EXEC | PROT_WRITE,
508                               MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
509         if (textpos == -1 ) {
510             fprintf(stderr, "Unable to allocate RAM for process text/data\n");
511             return -1;
512         }
513 
514         realdatastart = textpos + ntohl(hdr->data_start);
515         datapos = realdatastart + indx_len;
516         reloc = (textpos + ntohl(hdr->reloc_start) + indx_len);
517         memp = textpos;
518 
519 #ifdef CONFIG_BINFMT_ZFLAT
520 #error code needs checking
521         /*
522          * load it all in and treat it like a RAM load from now on
523          */
524         if (flags & FLAT_FLAG_GZIP) {
525                 result = decompress_exec(bprm, sizeof (struct flat_hdr),
526                                  (((char *) textpos) + sizeof (struct flat_hdr)),
527                                  (text_len + data_len + (relocs * sizeof(unsigned long))
528                                           - sizeof (struct flat_hdr)),
529                                  0);
530                 memmove((void *) datapos, (void *) realdatastart,
531                                 data_len + (relocs * sizeof(unsigned long)));
532         } else if (flags & FLAT_FLAG_GZDATA) {
533                 fpos = 0;
534                 result = bprm->file->f_op->read(bprm->file,
535                                 (char *) textpos, text_len, &fpos);
536                 if (result < (unsigned long) -4096)
537                         result = decompress_exec(bprm, text_len, (char *) datapos,
538                                          data_len + (relocs * sizeof(unsigned long)), 0);
539         }
540         else
541 #endif
542         {
543             result = target_pread(bprm->fd, textpos,
544                                   text_len, 0);
545             if (result >= 0) {
546                 result = target_pread(bprm->fd, datapos,
547                     data_len + (relocs * sizeof(abi_ulong)),
548                     ntohl(hdr->data_start));
549             }
550         }
551         if (result < 0) {
552             fprintf(stderr, "Unable to read code+data+bss\n");
553             return result;
554         }
555     }
556 
557     DBG_FLT("Mapping is 0x%x, Entry point is 0x%x, data_start is 0x%x\n",
558             (int)textpos, 0x00ffffff&ntohl(hdr->entry),
559             ntohl(hdr->data_start));
560 
561     /* The main program needs a little extra setup in the task structure */
562     start_code = textpos + sizeof (struct flat_hdr);
563     end_code = textpos + text_len;
564 
565     DBG_FLT("%s %s: TEXT=%x-%x DATA=%x-%x BSS=%x-%x\n",
566             id ? "Lib" : "Load", bprm->filename,
567             (int) start_code, (int) end_code,
568             (int) datapos,
569             (int) (datapos + data_len),
570             (int) (datapos + data_len),
571             (int) (((datapos + data_len + bss_len) + 3) & ~3));
572 
573     text_len -= sizeof(struct flat_hdr); /* the real code len */
574 
575     /* Store the current module values into the global library structure */
576     libinfo[id].start_code = start_code;
577     libinfo[id].start_data = datapos;
578     libinfo[id].end_data = datapos + data_len;
579     libinfo[id].start_brk = datapos + data_len + bss_len;
580     libinfo[id].text_len = text_len;
581     libinfo[id].loaded = 1;
582     libinfo[id].entry = (0x00ffffff & ntohl(hdr->entry)) + textpos;
583     libinfo[id].build_date = ntohl(hdr->build_date);
584 
585     /*
586      * We just load the allocations into some temporary memory to
587      * help simplify all this mumbo jumbo
588      *
589      * We've got two different sections of relocation entries.
590      * The first is the GOT which resides at the begining of the data segment
591      * and is terminated with a -1.  This one can be relocated in place.
592      * The second is the extra relocation entries tacked after the image's
593      * data segment. These require a little more processing as the entry is
594      * really an offset into the image which contains an offset into the
595      * image.
596      */
597     if (flags & FLAT_FLAG_GOTPIC) {
598         rp = datapos;
599         while (1) {
600             abi_ulong addr;
601             if (get_user_ual(addr, rp))
602                 return -EFAULT;
603             if (addr == -1)
604                 break;
605             if (addr) {
606                 addr = calc_reloc(addr, libinfo, id, 0);
607                 if (addr == RELOC_FAILED)
608                     return -ENOEXEC;
609                 if (put_user_ual(addr, rp))
610                     return -EFAULT;
611             }
612             rp += sizeof(abi_ulong);
613         }
614     }
615 
616     /*
617      * Now run through the relocation entries.
618      * We've got to be careful here as C++ produces relocatable zero
619      * entries in the constructor and destructor tables which are then
620      * tested for being not zero (which will always occur unless we're
621      * based from address zero).  This causes an endless loop as __start
622      * is at zero.  The solution used is to not relocate zero addresses.
623      * This has the negative side effect of not allowing a global data
624      * reference to be statically initialised to _stext (I've moved
625      * __start to address 4 so that is okay).
626      */
627     if (rev > OLD_FLAT_VERSION) {
628         for (i = 0; i < relocs; i++) {
629             abi_ulong addr, relval;
630 
631             /* Get the address of the pointer to be
632                relocated (of course, the address has to be
633                relocated first).  */
634             if (get_user_ual(relval, reloc + i * sizeof(abi_ulong)))
635                 return -EFAULT;
636             addr = flat_get_relocate_addr(relval);
637             rp = calc_reloc(addr, libinfo, id, 1);
638             if (rp == RELOC_FAILED)
639                 return -ENOEXEC;
640 
641             /* Get the pointer's value.  */
642             if (get_user_ual(addr, rp))
643                 return -EFAULT;
644             if (addr != 0) {
645                 /*
646                  * Do the relocation.  PIC relocs in the data section are
647                  * already in target order
648                  */
649 
650 #ifndef TARGET_WORDS_BIGENDIAN
651                 if ((flags & FLAT_FLAG_GOTPIC) == 0)
652                     addr = bswap32(addr);
653 #endif
654                 addr = calc_reloc(addr, libinfo, id, 0);
655                 if (addr == RELOC_FAILED)
656                     return -ENOEXEC;
657 
658                 /* Write back the relocated pointer.  */
659                 if (put_user_ual(addr, rp))
660                     return -EFAULT;
661             }
662         }
663     } else {
664         for (i = 0; i < relocs; i++) {
665             abi_ulong relval;
666             if (get_user_ual(relval, reloc + i * sizeof(abi_ulong)))
667                 return -EFAULT;
668             old_reloc(&libinfo[0], relval);
669         }
670     }
671 
672     /* zero the BSS.  */
673     memset((void *)((unsigned long)datapos + data_len), 0, bss_len);
674 
675     return 0;
676 }
677 
678 
679 /****************************************************************************/
680 #ifdef CONFIG_BINFMT_SHARED_FLAT
681 
682 /*
683  * Load a shared library into memory.  The library gets its own data
684  * segment (including bss) but not argv/argc/environ.
685  */
686 
load_flat_shared_library(int id,struct lib_info * libs)687 static int load_flat_shared_library(int id, struct lib_info *libs)
688 {
689 	struct linux_binprm bprm;
690 	int res;
691 	char buf[16];
692 
693 	/* Create the file name */
694 	sprintf(buf, "/lib/lib%d.so", id);
695 
696 	/* Open the file up */
697 	bprm.filename = buf;
698 	bprm.file = open_exec(bprm.filename);
699 	res = PTR_ERR(bprm.file);
700 	if (IS_ERR(bprm.file))
701 		return res;
702 
703 	res = prepare_binprm(&bprm);
704 
705 	if (res <= (unsigned long)-4096)
706 		res = load_flat_file(&bprm, libs, id, NULL);
707 	if (bprm.file) {
708 		allow_write_access(bprm.file);
709 		fput(bprm.file);
710 		bprm.file = NULL;
711 	}
712 	return(res);
713 }
714 
715 #endif /* CONFIG_BINFMT_SHARED_FLAT */
716 
load_flt_binary(struct linux_binprm * bprm,struct target_pt_regs * regs,struct image_info * info)717 int load_flt_binary(struct linux_binprm * bprm, struct target_pt_regs * regs,
718                     struct image_info * info)
719 {
720     struct lib_info libinfo[MAX_SHARED_LIBS];
721     abi_ulong p = bprm->p;
722     abi_ulong stack_len;
723     abi_ulong start_addr;
724     abi_ulong sp;
725     int res;
726     int i, j;
727 
728     memset(libinfo, 0, sizeof(libinfo));
729     /*
730      * We have to add the size of our arguments to our stack size
731      * otherwise it's too easy for users to create stack overflows
732      * by passing in a huge argument list.  And yes,  we have to be
733      * pedantic and include space for the argv/envp array as it may have
734      * a lot of entries.
735      */
736 #define TOP_OF_ARGS (TARGET_PAGE_SIZE * MAX_ARG_PAGES - sizeof(void *))
737     stack_len = TOP_OF_ARGS - bprm->p;             /* the strings */
738     stack_len += (bprm->argc + 1) * 4; /* the argv array */
739     stack_len += (bprm->envc + 1) * 4; /* the envp array */
740 
741 
742     res = load_flat_file(bprm, libinfo, 0, &stack_len);
743     if (res > (unsigned long)-4096)
744             return res;
745 
746     /* Update data segment pointers for all libraries */
747     for (i=0; i<MAX_SHARED_LIBS; i++) {
748         if (libinfo[i].loaded) {
749             abi_ulong p;
750             p = libinfo[i].start_data;
751             for (j=0; j<MAX_SHARED_LIBS; j++) {
752                 p -= 4;
753                 /* FIXME - handle put_user() failures */
754                 if (put_user_ual(libinfo[j].loaded
755                                  ? libinfo[j].start_data
756                                  : UNLOADED_LIB,
757                                  p))
758                     return -EFAULT;
759             }
760         }
761     }
762 
763     p = ((libinfo[0].start_brk + stack_len + 3) & ~3) - 4;
764     DBG_FLT("p=%x\n", (int)p);
765 
766     /* Copy argv/envp.  */
767     p = copy_strings(p, bprm->envc, bprm->envp);
768     p = copy_strings(p, bprm->argc, bprm->argv);
769     /* Align stack.  */
770     sp = p & ~(abi_ulong)(sizeof(abi_ulong) - 1);
771     /* Enforce final stack alignment of 16 bytes.  This is sufficient
772        for all current targets, and excess alignment is harmless.  */
773     stack_len = bprm->envc + bprm->argc + 2;
774     stack_len += 3;	/* argc, arvg, argp */
775     stack_len *= sizeof(abi_ulong);
776     if ((sp + stack_len) & 15)
777         sp -= 16 - ((sp + stack_len) & 15);
778     sp = loader_build_argptr(bprm->envc, bprm->argc, sp, p, 1);
779 
780     /* Fake some return addresses to ensure the call chain will
781      * initialise library in order for us.  We are required to call
782      * lib 1 first, then 2, ... and finally the main program (id 0).
783      */
784     start_addr = libinfo[0].entry;
785 
786 #ifdef CONFIG_BINFMT_SHARED_FLAT
787 #error here
788     for (i = MAX_SHARED_LIBS-1; i>0; i--) {
789             if (libinfo[i].loaded) {
790                     /* Push previos first to call address */
791                     --sp;
792                     if (put_user_ual(start_addr, sp))
793                         return -EFAULT;
794                     start_addr = libinfo[i].entry;
795             }
796     }
797 #endif
798 
799     /* Stash our initial stack pointer into the mm structure */
800     info->start_code = libinfo[0].start_code;
801     info->end_code = libinfo[0].start_code = libinfo[0].text_len;
802     info->start_data = libinfo[0].start_data;
803     info->end_data = libinfo[0].end_data;
804     info->start_brk = libinfo[0].start_brk;
805     info->start_stack = sp;
806     info->stack_limit = libinfo[0].start_brk;
807     info->entry = start_addr;
808     info->code_offset = info->start_code;
809     info->data_offset = info->start_data - libinfo[0].text_len;
810 
811     DBG_FLT("start_thread(entry=0x%x, start_stack=0x%x)\n",
812             (int)info->entry, (int)info->start_stack);
813 
814     return 0;
815 }
816