blob: afb7e9d521d2e648a2082fe28ec66b9195183ca7 [file] [log] [blame]
Linus Torvalds1da177e2005-04-16 15:20:36 -07001/****************************************************************************/
2/*
3 * linux/fs/binfmt_flat.c
4 *
5 * Copyright (C) 2000-2003 David McCullough <davidm@snapgear.com>
6 * Copyright (C) 2002 Greg Ungerer <gerg@snapgear.com>
7 * Copyright (C) 2002 SnapGear, by Paul Dale <pauli@snapgear.com>
8 * Copyright (C) 2000, 2001 Lineo, by David McCullough <davidm@lineo.com>
9 * based heavily on:
10 *
11 * linux/fs/binfmt_aout.c:
12 * Copyright (C) 1991, 1992, 1996 Linus Torvalds
13 * linux/fs/binfmt_flat.c for 2.0 kernel
14 * Copyright (C) 1998 Kenneth Albanowski <kjahds@kjahds.com>
15 * JAN/99 -- coded full program relocation (gerg@snapgear.com)
16 */
17
Nicolas Pitre4adbb6a2016-07-24 11:30:16 -040018#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
19
Linus Torvalds1da177e2005-04-16 15:20:36 -070020#include <linux/kernel.h>
21#include <linux/sched.h>
Ingo Molnar68db0cf2017-02-08 18:51:37 +010022#include <linux/sched/task_stack.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070023#include <linux/mm.h>
24#include <linux/mman.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070025#include <linux/errno.h>
26#include <linux/signal.h>
27#include <linux/string.h>
28#include <linux/fs.h>
29#include <linux/file.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070030#include <linux/ptrace.h>
31#include <linux/user.h>
32#include <linux/slab.h>
33#include <linux/binfmts.h>
34#include <linux/personality.h>
35#include <linux/init.h>
36#include <linux/flat.h>
Nicolas Pitre13c3f502016-07-24 11:30:15 -040037#include <linux/uaccess.h>
Nicolas Pitre472f95f2016-07-24 11:30:26 -040038#include <linux/vmalloc.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070039
40#include <asm/byteorder.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070041#include <asm/unaligned.h>
42#include <asm/cacheflush.h>
Oskar Schirmerc3dc5be2009-05-28 14:34:31 -070043#include <asm/page.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070044
45/****************************************************************************/
46
Oskar Schirmerc3dc5be2009-05-28 14:34:31 -070047/*
Mike Frysinger2e94de82010-06-04 14:14:53 -070048 * User data (data section and bss) needs to be aligned.
49 * We pick 0x20 here because it is the max value elf2flt has always
50 * used in producing FLAT files, and because it seems to be large
51 * enough to make all the gcc alignment related tests happy.
52 */
53#define FLAT_DATA_ALIGN (0x20)
54
55/*
56 * User data (stack) also needs to be aligned.
57 * Here we can be a bit looser than the data sections since this
58 * needs to only meet arch ABI requirements.
Oskar Schirmerc3dc5be2009-05-28 14:34:31 -070059 */
Mike Frysinger29520952010-06-29 15:05:21 -070060#define FLAT_STACK_ALIGN max_t(unsigned long, sizeof(void *), ARCH_SLAB_MINALIGN)
Oskar Schirmerc3dc5be2009-05-28 14:34:31 -070061
Linus Torvalds1da177e2005-04-16 15:20:36 -070062#define RELOC_FAILED 0xff00ff01 /* Relocation incorrect somewhere */
63#define UNLOADED_LIB 0x7ff000ff /* Placeholder for unused library */
64
65struct lib_info {
66 struct {
67 unsigned long start_code; /* Start of text segment */
68 unsigned long start_data; /* Start of data segment */
69 unsigned long start_brk; /* End of data segment */
70 unsigned long text_len; /* Length of text segment */
71 unsigned long entry; /* Start address for this module */
72 unsigned long build_date; /* When this one was compiled */
Nicolas Pitre13c3f502016-07-24 11:30:15 -040073 bool loaded; /* Has this library been loaded? */
Linus Torvalds1da177e2005-04-16 15:20:36 -070074 } lib_list[MAX_SHARED_LIBS];
75};
76
77#ifdef CONFIG_BINFMT_SHARED_FLAT
78static int load_flat_shared_library(int id, struct lib_info *p);
79#endif
80
Al Viro71613c32012-10-20 22:00:48 -040081static int load_flat_binary(struct linux_binprm *);
Masami Hiramatsuf6151df2009-12-17 15:27:16 -080082static int flat_core_dump(struct coredump_params *cprm);
Linus Torvalds1da177e2005-04-16 15:20:36 -070083
Linus Torvalds1da177e2005-04-16 15:20:36 -070084static struct linux_binfmt flat_format = {
85 .module = THIS_MODULE,
86 .load_binary = load_flat_binary,
87 .core_dump = flat_core_dump,
88 .min_coredump = PAGE_SIZE
89};
90
91/****************************************************************************/
92/*
93 * Routine writes a core dump image in the current directory.
94 * Currently only a stub-function.
95 */
96
Masami Hiramatsuf6151df2009-12-17 15:27:16 -080097static int flat_core_dump(struct coredump_params *cprm)
Linus Torvalds1da177e2005-04-16 15:20:36 -070098{
Nicolas Pitre4adbb6a2016-07-24 11:30:16 -040099 pr_warn("Process %s:%d received signr %d and should have core dumped\n",
100 current->comm, current->pid, cprm->siginfo->si_signo);
Nicolas Pitre13c3f502016-07-24 11:30:15 -0400101 return 1;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700102}
103
104/****************************************************************************/
105/*
106 * create_flat_tables() parses the env- and arg-strings in new user
107 * memory and creates the pointer tables from them, and puts their
Nicolas Pitrea97d1572016-07-24 11:30:20 -0400108 * addresses on the "stack", recording the new stack pointer value.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700109 */
110
Nicolas Pitrea97d1572016-07-24 11:30:20 -0400111static int create_flat_tables(struct linux_binprm *bprm, unsigned long arg_start)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700112{
Nicolas Pitrea97d1572016-07-24 11:30:20 -0400113 char __user *p;
114 unsigned long __user *sp;
115 long i, len;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700116
Nicolas Pitrea97d1572016-07-24 11:30:20 -0400117 p = (char __user *)arg_start;
118 sp = (unsigned long __user *)current->mm->start_stack;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700119
Nicolas Pitrea97d1572016-07-24 11:30:20 -0400120 sp -= bprm->envc + 1;
121 sp -= bprm->argc + 1;
122 sp -= flat_argvp_envp_on_stack() ? 2 : 0;
123 sp -= 1; /* &argc */
124
125 current->mm->start_stack = (unsigned long)sp & -FLAT_STACK_ALIGN;
126 sp = (unsigned long __user *)current->mm->start_stack;
127
128 __put_user(bprm->argc, sp++);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700129 if (flat_argvp_envp_on_stack()) {
Nicolas Pitrea97d1572016-07-24 11:30:20 -0400130 unsigned long argv, envp;
131 argv = (unsigned long)(sp + 2);
132 envp = (unsigned long)(sp + 2 + bprm->argc + 1);
133 __put_user(argv, sp++);
134 __put_user(envp, sp++);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700135 }
136
Nicolas Pitrea97d1572016-07-24 11:30:20 -0400137 current->mm->arg_start = (unsigned long)p;
138 for (i = bprm->argc; i > 0; i--) {
139 __put_user((unsigned long)p, sp++);
140 len = strnlen_user(p, MAX_ARG_STRLEN);
141 if (!len || len > MAX_ARG_STRLEN)
142 return -EINVAL;
143 p += len;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700144 }
Nicolas Pitrea97d1572016-07-24 11:30:20 -0400145 __put_user(0, sp++);
146 current->mm->arg_end = (unsigned long)p;
147
148 current->mm->env_start = (unsigned long) p;
149 for (i = bprm->envc; i > 0; i--) {
150 __put_user((unsigned long)p, sp++);
151 len = strnlen_user(p, MAX_ARG_STRLEN);
152 if (!len || len > MAX_ARG_STRLEN)
153 return -EINVAL;
154 p += len;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700155 }
Nicolas Pitrea97d1572016-07-24 11:30:20 -0400156 __put_user(0, sp++);
157 current->mm->env_end = (unsigned long)p;
158
159 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700160}
161
162/****************************************************************************/
163
164#ifdef CONFIG_BINFMT_ZFLAT
165
166#include <linux/zlib.h>
167
168#define LBUFSIZE 4000
169
170/* gzip flag byte */
171#define ASCII_FLAG 0x01 /* bit 0 set: file probably ASCII text */
172#define CONTINUATION 0x02 /* bit 1 set: continuation of multi-part gzip file */
173#define EXTRA_FIELD 0x04 /* bit 2 set: extra field present */
174#define ORIG_NAME 0x08 /* bit 3 set: original file name present */
175#define COMMENT 0x10 /* bit 4 set: file comment present */
176#define ENCRYPTED 0x20 /* bit 5 set: file is encrypted */
177#define RESERVED 0xC0 /* bit 6,7: reserved */
178
Christoph Hellwigbdd1d2d2017-09-01 17:39:13 +0200179static int decompress_exec(struct linux_binprm *bprm, loff_t fpos, char *dst,
180 long len, int fd)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700181{
182 unsigned char *buf;
183 z_stream strm;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700184 int ret, retval;
185
Christoph Hellwigbdd1d2d2017-09-01 17:39:13 +0200186 pr_debug("decompress_exec(offset=%llx,buf=%p,len=%lx)\n", fpos, dst, len);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700187
188 memset(&strm, 0, sizeof(strm));
189 strm.workspace = kmalloc(zlib_inflate_workspacesize(), GFP_KERNEL);
190 if (strm.workspace == NULL) {
Nicolas Pitre4adbb6a2016-07-24 11:30:16 -0400191 pr_debug("no memory for decompress workspace\n");
Linus Torvalds1da177e2005-04-16 15:20:36 -0700192 return -ENOMEM;
193 }
194 buf = kmalloc(LBUFSIZE, GFP_KERNEL);
195 if (buf == NULL) {
Nicolas Pitre4adbb6a2016-07-24 11:30:16 -0400196 pr_debug("no memory for read buffer\n");
Linus Torvalds1da177e2005-04-16 15:20:36 -0700197 retval = -ENOMEM;
198 goto out_free;
199 }
200
201 /* Read in first chunk of data and parse gzip header. */
Christoph Hellwigbdd1d2d2017-09-01 17:39:13 +0200202 ret = kernel_read(bprm->file, buf, LBUFSIZE, &fpos);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700203
204 strm.next_in = buf;
205 strm.avail_in = ret;
206 strm.total_in = 0;
207
208 retval = -ENOEXEC;
209
210 /* Check minimum size -- gzip header */
211 if (ret < 10) {
Nicolas Pitre4adbb6a2016-07-24 11:30:16 -0400212 pr_debug("file too small?\n");
Linus Torvalds1da177e2005-04-16 15:20:36 -0700213 goto out_free_buf;
214 }
215
216 /* Check gzip magic number */
217 if ((buf[0] != 037) || ((buf[1] != 0213) && (buf[1] != 0236))) {
Nicolas Pitre4adbb6a2016-07-24 11:30:16 -0400218 pr_debug("unknown compression magic?\n");
Linus Torvalds1da177e2005-04-16 15:20:36 -0700219 goto out_free_buf;
220 }
221
222 /* Check gzip method */
223 if (buf[2] != 8) {
Nicolas Pitre4adbb6a2016-07-24 11:30:16 -0400224 pr_debug("unknown compression method?\n");
Linus Torvalds1da177e2005-04-16 15:20:36 -0700225 goto out_free_buf;
226 }
227 /* Check gzip flags */
228 if ((buf[3] & ENCRYPTED) || (buf[3] & CONTINUATION) ||
229 (buf[3] & RESERVED)) {
Nicolas Pitre4adbb6a2016-07-24 11:30:16 -0400230 pr_debug("unknown flags?\n");
Linus Torvalds1da177e2005-04-16 15:20:36 -0700231 goto out_free_buf;
232 }
233
234 ret = 10;
235 if (buf[3] & EXTRA_FIELD) {
236 ret += 2 + buf[10] + (buf[11] << 8);
Nicolas Pitre13c3f502016-07-24 11:30:15 -0400237 if (unlikely(ret >= LBUFSIZE)) {
Nicolas Pitre4adbb6a2016-07-24 11:30:16 -0400238 pr_debug("buffer overflow (EXTRA)?\n");
Linus Torvalds1da177e2005-04-16 15:20:36 -0700239 goto out_free_buf;
240 }
241 }
242 if (buf[3] & ORIG_NAME) {
Volodymyr G. Lukiianykf4cfb182008-10-15 22:01:15 -0700243 while (ret < LBUFSIZE && buf[ret++] != 0)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700244 ;
Nicolas Pitre13c3f502016-07-24 11:30:15 -0400245 if (unlikely(ret == LBUFSIZE)) {
Nicolas Pitre4adbb6a2016-07-24 11:30:16 -0400246 pr_debug("buffer overflow (ORIG_NAME)?\n");
Linus Torvalds1da177e2005-04-16 15:20:36 -0700247 goto out_free_buf;
248 }
249 }
250 if (buf[3] & COMMENT) {
Volodymyr G. Lukiianykf4cfb182008-10-15 22:01:15 -0700251 while (ret < LBUFSIZE && buf[ret++] != 0)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700252 ;
Nicolas Pitre13c3f502016-07-24 11:30:15 -0400253 if (unlikely(ret == LBUFSIZE)) {
Nicolas Pitre4adbb6a2016-07-24 11:30:16 -0400254 pr_debug("buffer overflow (COMMENT)?\n");
Linus Torvalds1da177e2005-04-16 15:20:36 -0700255 goto out_free_buf;
256 }
257 }
258
259 strm.next_in += ret;
260 strm.avail_in -= ret;
261
262 strm.next_out = dst;
263 strm.avail_out = len;
264 strm.total_out = 0;
265
266 if (zlib_inflateInit2(&strm, -MAX_WBITS) != Z_OK) {
Nicolas Pitre4adbb6a2016-07-24 11:30:16 -0400267 pr_debug("zlib init failed?\n");
Linus Torvalds1da177e2005-04-16 15:20:36 -0700268 goto out_free_buf;
269 }
270
271 while ((ret = zlib_inflate(&strm, Z_NO_FLUSH)) == Z_OK) {
Christoph Hellwigbdd1d2d2017-09-01 17:39:13 +0200272 ret = kernel_read(bprm->file, buf, LBUFSIZE, &fpos);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700273 if (ret <= 0)
274 break;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700275 len -= ret;
276
277 strm.next_in = buf;
278 strm.avail_in = ret;
279 strm.total_in = 0;
280 }
281
282 if (ret < 0) {
Nicolas Pitre4adbb6a2016-07-24 11:30:16 -0400283 pr_debug("decompression failed (%d), %s\n",
Linus Torvalds1da177e2005-04-16 15:20:36 -0700284 ret, strm.msg);
285 goto out_zlib;
286 }
287
288 retval = 0;
289out_zlib:
290 zlib_inflateEnd(&strm);
291out_free_buf:
292 kfree(buf);
293out_free:
294 kfree(strm.workspace);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700295 return retval;
296}
297
298#endif /* CONFIG_BINFMT_ZFLAT */
299
300/****************************************************************************/
301
302static unsigned long
303calc_reloc(unsigned long r, struct lib_info *p, int curid, int internalp)
304{
305 unsigned long addr;
306 int id;
307 unsigned long start_brk;
308 unsigned long start_data;
309 unsigned long text_len;
310 unsigned long start_code;
311
312#ifdef CONFIG_BINFMT_SHARED_FLAT
313 if (r == 0)
314 id = curid; /* Relocs of 0 are always self referring */
315 else {
316 id = (r >> 24) & 0xff; /* Find ID for this reloc */
317 r &= 0x00ffffff; /* Trim ID off here */
318 }
319 if (id >= MAX_SHARED_LIBS) {
Nicolas Pitre4adbb6a2016-07-24 11:30:16 -0400320 pr_err("reference 0x%lx to shared library %d", r, id);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700321 goto failed;
322 }
323 if (curid != id) {
324 if (internalp) {
Nicolas Pitre4adbb6a2016-07-24 11:30:16 -0400325 pr_err("reloc address 0x%lx not in same module "
326 "(%d != %d)", r, curid, id);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700327 goto failed;
Nicolas Pitre13c3f502016-07-24 11:30:15 -0400328 } else if (!p->lib_list[id].loaded &&
329 load_flat_shared_library(id, p) < 0) {
Nicolas Pitre4adbb6a2016-07-24 11:30:16 -0400330 pr_err("failed to load library %d", id);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700331 goto failed;
332 }
333 /* Check versioning information (i.e. time stamps) */
334 if (p->lib_list[id].build_date && p->lib_list[curid].build_date &&
335 p->lib_list[curid].build_date < p->lib_list[id].build_date) {
Nicolas Pitre4adbb6a2016-07-24 11:30:16 -0400336 pr_err("library %d is younger than %d", id, curid);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700337 goto failed;
338 }
339 }
340#else
341 id = 0;
342#endif
343
344 start_brk = p->lib_list[id].start_brk;
345 start_data = p->lib_list[id].start_data;
346 start_code = p->lib_list[id].start_code;
347 text_len = p->lib_list[id].text_len;
348
349 if (!flat_reloc_valid(r, start_brk - start_data + text_len)) {
Nicolas Pitre4adbb6a2016-07-24 11:30:16 -0400350 pr_err("reloc outside program 0x%lx (0 - 0x%lx/0x%lx)",
Nicolas Pitre13c3f502016-07-24 11:30:15 -0400351 r, start_brk-start_data+text_len, text_len);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700352 goto failed;
353 }
354
355 if (r < text_len) /* In text segment */
356 addr = r + start_code;
357 else /* In data segment */
358 addr = r - text_len + start_data;
359
360 /* Range checked already above so doing the range tests is redundant...*/
Nicolas Pitre13c3f502016-07-24 11:30:15 -0400361 return addr;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700362
363failed:
Nicolas Pitre4adbb6a2016-07-24 11:30:16 -0400364 pr_cont(", killing %s!\n", current->comm);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700365 send_sig(SIGSEGV, current, 0);
366
367 return RELOC_FAILED;
368}
369
370/****************************************************************************/
371
Axel Lin34303432014-06-04 16:12:15 -0700372static void old_reloc(unsigned long rl)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700373{
Nicolas Pitre13c3f502016-07-24 11:30:15 -0400374 static const char *segment[] = { "TEXT", "DATA", "BSS", "*UNKNOWN*" };
Linus Torvalds1da177e2005-04-16 15:20:36 -0700375 flat_v2_reloc_t r;
Nicolas Pitre1b2ce442016-07-24 11:30:22 -0400376 unsigned long __user *ptr;
377 unsigned long val;
Nicolas Pitre13c3f502016-07-24 11:30:15 -0400378
Linus Torvalds1da177e2005-04-16 15:20:36 -0700379 r.value = rl;
380#if defined(CONFIG_COLDFIRE)
Nicolas Pitre1b2ce442016-07-24 11:30:22 -0400381 ptr = (unsigned long __user *)(current->mm->start_code + r.reloc.offset);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700382#else
Nicolas Pitre1b2ce442016-07-24 11:30:22 -0400383 ptr = (unsigned long __user *)(current->mm->start_data + r.reloc.offset);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700384#endif
Nicolas Pitre1b2ce442016-07-24 11:30:22 -0400385 get_user(val, ptr);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700386
Nicolas Pitre4adbb6a2016-07-24 11:30:16 -0400387 pr_debug("Relocation of variable at DATASEG+%x "
388 "(address %p, currently %lx) into segment %s\n",
Nicolas Pitre1b2ce442016-07-24 11:30:22 -0400389 r.reloc.offset, ptr, val, segment[r.reloc.type]);
Nicolas Pitre13c3f502016-07-24 11:30:15 -0400390
Linus Torvalds1da177e2005-04-16 15:20:36 -0700391 switch (r.reloc.type) {
392 case OLD_FLAT_RELOC_TYPE_TEXT:
Nicolas Pitre1b2ce442016-07-24 11:30:22 -0400393 val += current->mm->start_code;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700394 break;
395 case OLD_FLAT_RELOC_TYPE_DATA:
Nicolas Pitre1b2ce442016-07-24 11:30:22 -0400396 val += current->mm->start_data;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700397 break;
398 case OLD_FLAT_RELOC_TYPE_BSS:
Nicolas Pitre1b2ce442016-07-24 11:30:22 -0400399 val += current->mm->end_data;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700400 break;
401 default:
Nicolas Pitre4adbb6a2016-07-24 11:30:16 -0400402 pr_err("Unknown relocation type=%x\n", r.reloc.type);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700403 break;
404 }
Nicolas Pitre1b2ce442016-07-24 11:30:22 -0400405 put_user(val, ptr);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700406
Nicolas Pitre1b2ce442016-07-24 11:30:22 -0400407 pr_debug("Relocation became %lx\n", val);
Nicolas Pitre13c3f502016-07-24 11:30:15 -0400408}
Linus Torvalds1da177e2005-04-16 15:20:36 -0700409
410/****************************************************************************/
411
Nicolas Pitre13c3f502016-07-24 11:30:15 -0400412static int load_flat_file(struct linux_binprm *bprm,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700413 struct lib_info *libinfo, int id, unsigned long *extra_stack)
414{
Nicolas Pitre13c3f502016-07-24 11:30:15 -0400415 struct flat_hdr *hdr;
416 unsigned long textpos, datapos, realdatastart;
Al Viro468138d2017-05-02 19:52:17 -0400417 u32 text_len, data_len, bss_len, stack_len, full_data, flags;
Nicolas Pitre13c3f502016-07-24 11:30:15 -0400418 unsigned long len, memp, memp_size, extra, rlim;
Al Viro468138d2017-05-02 19:52:17 -0400419 u32 __user *reloc, *rp;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700420 struct inode *inode;
Nicolas Pitre13c3f502016-07-24 11:30:15 -0400421 int i, rev, relocs;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700422 loff_t fpos;
423 unsigned long start_code, end_code;
Nicolas Pitre13c3f502016-07-24 11:30:15 -0400424 ssize_t result;
Luke Yang1ad3dcc2006-03-25 03:08:24 -0800425 int ret;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700426
427 hdr = ((struct flat_hdr *) bprm->buf); /* exec-header */
Al Viro496ad9a2013-01-23 17:07:38 -0500428 inode = file_inode(bprm->file);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700429
430 text_len = ntohl(hdr->data_start);
431 data_len = ntohl(hdr->data_end) - ntohl(hdr->data_start);
432 bss_len = ntohl(hdr->bss_end) - ntohl(hdr->data_end);
433 stack_len = ntohl(hdr->stack_size);
434 if (extra_stack) {
435 stack_len += *extra_stack;
436 *extra_stack = stack_len;
437 }
438 relocs = ntohl(hdr->reloc_count);
439 flags = ntohl(hdr->flags);
440 rev = ntohl(hdr->rev);
Al Viro3dc20cb2013-04-13 20:31:37 -0400441 full_data = data_len + relocs * sizeof(unsigned long);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700442
Greg Ungerer845884d2006-01-10 16:59:37 +1000443 if (strncmp(hdr->magic, "bFLT", 4)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700444 /*
Mike Frysingere2a366d2008-02-14 19:31:29 -0800445 * Previously, here was a printk to tell people
446 * "BINFMT_FLAT: bad header magic".
447 * But for the kernel which also use ELF FD-PIC format, this
448 * error message is confusing.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700449 * because a lot of people do not manage to produce good
Linus Torvalds1da177e2005-04-16 15:20:36 -0700450 */
Luke Yang1ad3dcc2006-03-25 03:08:24 -0800451 ret = -ENOEXEC;
452 goto err;
Greg Ungerer845884d2006-01-10 16:59:37 +1000453 }
454
455 if (flags & FLAT_FLAG_KTRACE)
Nicolas Pitre4adbb6a2016-07-24 11:30:16 -0400456 pr_info("Loading file: %s\n", bprm->filename);
Greg Ungerer845884d2006-01-10 16:59:37 +1000457
458 if (rev != FLAT_VERSION && rev != OLD_FLAT_VERSION) {
Nicolas Pitre4adbb6a2016-07-24 11:30:16 -0400459 pr_err("bad flat file version 0x%x (supported 0x%lx and 0x%lx)\n",
460 rev, FLAT_VERSION, OLD_FLAT_VERSION);
Luke Yang1ad3dcc2006-03-25 03:08:24 -0800461 ret = -ENOEXEC;
462 goto err;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700463 }
Nicolas Pitre13c3f502016-07-24 11:30:15 -0400464
Linus Torvalds1da177e2005-04-16 15:20:36 -0700465 /* Don't allow old format executables to use shared libraries */
466 if (rev == OLD_FLAT_VERSION && id != 0) {
Nicolas Pitre4adbb6a2016-07-24 11:30:16 -0400467 pr_err("shared libraries are not available before rev 0x%lx\n",
468 FLAT_VERSION);
Luke Yang1ad3dcc2006-03-25 03:08:24 -0800469 ret = -ENOEXEC;
470 goto err;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700471 }
472
473 /*
Nicolas Pitrec995ee22016-07-24 11:30:17 -0400474 * Make sure the header params are sane.
475 * 28 bits (256 MB) is way more than reasonable in this case.
476 * If some top bits are set we have probable binary corruption.
477 */
478 if ((text_len | data_len | bss_len | stack_len | full_data) >> 28) {
479 pr_err("bad header\n");
480 ret = -ENOEXEC;
481 goto err;
482 }
483
484 /*
Linus Torvalds1da177e2005-04-16 15:20:36 -0700485 * fix up the flags for the older format, there were all kinds
486 * of endian hacks, this only works for the simple cases
487 */
488 if (rev == OLD_FLAT_VERSION && flat_old_ram_flag(flags))
489 flags = FLAT_FLAG_RAM;
490
491#ifndef CONFIG_BINFMT_ZFLAT
492 if (flags & (FLAT_FLAG_GZIP|FLAT_FLAG_GZDATA)) {
Nicolas Pitre4adbb6a2016-07-24 11:30:16 -0400493 pr_err("Support for ZFLAT executables is not enabled.\n");
Luke Yang1ad3dcc2006-03-25 03:08:24 -0800494 ret = -ENOEXEC;
495 goto err;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700496 }
497#endif
498
499 /*
500 * Check initial limits. This avoids letting people circumvent
501 * size limits imposed on them by creating programs with large
502 * arrays in the data or bss.
503 */
Jiri Slabyd554ed892010-03-05 13:42:42 -0800504 rlim = rlimit(RLIMIT_DATA);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700505 if (rlim >= RLIM_INFINITY)
506 rlim = ~0;
Luke Yang1ad3dcc2006-03-25 03:08:24 -0800507 if (data_len + bss_len > rlim) {
508 ret = -ENOMEM;
509 goto err;
510 }
511
Linus Torvalds1da177e2005-04-16 15:20:36 -0700512 /* Flush all traces of the currently running executable */
513 if (id == 0) {
Nicolas Pitre13c3f502016-07-24 11:30:15 -0400514 ret = flush_old_exec(bprm);
515 if (ret)
Andrew Mortondf889122006-05-20 15:00:01 -0700516 goto err;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700517
518 /* OK, This is the point of no return */
Malcolm Parsonsfcc18e82006-06-26 11:49:41 +1000519 set_personality(PER_LINUX_32BIT);
Linus Torvalds221af7f2010-01-28 22:14:42 -0800520 setup_new_exec(bprm);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700521 }
522
523 /*
524 * calculate the extra space we need to map in
525 */
Andrew Morton0e647c02007-10-16 23:27:26 -0700526 extra = max_t(unsigned long, bss_len + stack_len,
527 relocs * sizeof(unsigned long));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700528
529 /*
530 * there are a couple of cases here, the separate code/data
531 * case, and then the fully copied to RAM case which lumps
532 * it all together.
533 */
Nicolas Pitre015feac2016-07-24 11:30:25 -0400534 if (!IS_ENABLED(CONFIG_MMU) && !(flags & (FLAT_FLAG_RAM|FLAT_FLAG_GZIP))) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700535 /*
536 * this should give us a ROM ptr, but if it doesn't we don't
537 * really care
538 */
Nicolas Pitre4adbb6a2016-07-24 11:30:16 -0400539 pr_debug("ROM mapping of file (we hope)\n");
Linus Torvalds1da177e2005-04-16 15:20:36 -0700540
Linus Torvalds6be5ceb2012-04-20 17:13:58 -0700541 textpos = vm_mmap(bprm->file, 0, text_len, PROT_READ|PROT_EXEC,
Matt Helsley925d1c42008-04-29 01:01:36 -0700542 MAP_PRIVATE|MAP_EXECUTABLE, 0);
Mike Frysinger0b8c78f2009-09-23 15:57:07 -0700543 if (!textpos || IS_ERR_VALUE(textpos)) {
Luke Yang1ad3dcc2006-03-25 03:08:24 -0800544 ret = textpos;
Nicolas Pitre13c3f502016-07-24 11:30:15 -0400545 if (!textpos)
546 ret = -ENOMEM;
Nicolas Pitre4adbb6a2016-07-24 11:30:16 -0400547 pr_err("Unable to mmap process text, errno %d\n", ret);
Andrew Mortondf889122006-05-20 15:00:01 -0700548 goto err;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700549 }
550
Greg Ungerer72613e5f2007-02-07 12:03:08 +1000551 len = data_len + extra + MAX_SHARED_LIBS * sizeof(unsigned long);
David Howells0f3e4422009-01-08 12:04:47 +0000552 len = PAGE_ALIGN(len);
Nicolas Pitre13c3f502016-07-24 11:30:15 -0400553 realdatastart = vm_mmap(NULL, 0, len,
Greg Ungerer72613e5f2007-02-07 12:03:08 +1000554 PROT_READ|PROT_WRITE|PROT_EXEC, MAP_PRIVATE, 0);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700555
Mike Frysinger0b8c78f2009-09-23 15:57:07 -0700556 if (realdatastart == 0 || IS_ERR_VALUE(realdatastart)) {
Luke Yang1ad3dcc2006-03-25 03:08:24 -0800557 ret = realdatastart;
Nicolas Pitre13c3f502016-07-24 11:30:15 -0400558 if (!realdatastart)
559 ret = -ENOMEM;
Nicolas Pitre4adbb6a2016-07-24 11:30:16 -0400560 pr_err("Unable to allocate RAM for process data, "
Nicolas Pitre13c3f502016-07-24 11:30:15 -0400561 "errno %d\n", ret);
562 vm_munmap(textpos, text_len);
Andrew Mortondf889122006-05-20 15:00:01 -0700563 goto err;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700564 }
Oskar Schirmerc3dc5be2009-05-28 14:34:31 -0700565 datapos = ALIGN(realdatastart +
566 MAX_SHARED_LIBS * sizeof(unsigned long),
567 FLAT_DATA_ALIGN);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700568
Geert Uytterhoevena8605422017-07-16 13:57:27 +0200569 pr_debug("Allocated data+bss+stack (%u bytes): %lx\n",
Nicolas Pitre4adbb6a2016-07-24 11:30:16 -0400570 data_len + bss_len + stack_len, datapos);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700571
572 fpos = ntohl(hdr->data_start);
573#ifdef CONFIG_BINFMT_ZFLAT
574 if (flags & FLAT_FLAG_GZDATA) {
Nicolas Pitre13c3f502016-07-24 11:30:15 -0400575 result = decompress_exec(bprm, fpos, (char *)datapos,
Al Viro3dc20cb2013-04-13 20:31:37 -0400576 full_data, 0);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700577 } else
578#endif
579 {
Al Viro3dc20cb2013-04-13 20:31:37 -0400580 result = read_code(bprm->file, datapos, fpos,
581 full_data);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700582 }
Mike Frysinger0b8c78f2009-09-23 15:57:07 -0700583 if (IS_ERR_VALUE(result)) {
Nicolas Pitre13c3f502016-07-24 11:30:15 -0400584 ret = result;
Nicolas Pitre4adbb6a2016-07-24 11:30:16 -0400585 pr_err("Unable to read data+bss, errno %d\n", ret);
Al Viro7696e0c32012-05-30 01:56:23 -0400586 vm_munmap(textpos, text_len);
587 vm_munmap(realdatastart, len);
Andrew Mortondf889122006-05-20 15:00:01 -0700588 goto err;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700589 }
590
Al Viro468138d2017-05-02 19:52:17 -0400591 reloc = (u32 __user *)
Nicolas Pitre13c3f502016-07-24 11:30:15 -0400592 (datapos + (ntohl(hdr->reloc_start) - text_len));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700593 memp = realdatastart;
David Howells0f3e4422009-01-08 12:04:47 +0000594 memp_size = len;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700595 } else {
596
Al Viro468138d2017-05-02 19:52:17 -0400597 len = text_len + data_len + extra + MAX_SHARED_LIBS * sizeof(u32);
David Howells0f3e4422009-01-08 12:04:47 +0000598 len = PAGE_ALIGN(len);
Nicolas Pitre13c3f502016-07-24 11:30:15 -0400599 textpos = vm_mmap(NULL, 0, len,
Greg Ungerer72613e5f2007-02-07 12:03:08 +1000600 PROT_READ | PROT_EXEC | PROT_WRITE, MAP_PRIVATE, 0);
Greg Ungerer72613e5f2007-02-07 12:03:08 +1000601
Mike Frysinger0b8c78f2009-09-23 15:57:07 -0700602 if (!textpos || IS_ERR_VALUE(textpos)) {
Luke Yang1ad3dcc2006-03-25 03:08:24 -0800603 ret = textpos;
Nicolas Pitre13c3f502016-07-24 11:30:15 -0400604 if (!textpos)
605 ret = -ENOMEM;
Nicolas Pitre4adbb6a2016-07-24 11:30:16 -0400606 pr_err("Unable to allocate RAM for process text/data, "
Nicolas Pitre13c3f502016-07-24 11:30:15 -0400607 "errno %d\n", ret);
Andrew Mortondf889122006-05-20 15:00:01 -0700608 goto err;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700609 }
610
611 realdatastart = textpos + ntohl(hdr->data_start);
Oskar Schirmerc3dc5be2009-05-28 14:34:31 -0700612 datapos = ALIGN(realdatastart +
Al Viro468138d2017-05-02 19:52:17 -0400613 MAX_SHARED_LIBS * sizeof(u32),
Oskar Schirmerc3dc5be2009-05-28 14:34:31 -0700614 FLAT_DATA_ALIGN);
615
Al Viro468138d2017-05-02 19:52:17 -0400616 reloc = (u32 __user *)
Oskar Schirmerc3dc5be2009-05-28 14:34:31 -0700617 (datapos + (ntohl(hdr->reloc_start) - text_len));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700618 memp = textpos;
David Howells0f3e4422009-01-08 12:04:47 +0000619 memp_size = len;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700620#ifdef CONFIG_BINFMT_ZFLAT
621 /*
622 * load it all in and treat it like a RAM load from now on
623 */
624 if (flags & FLAT_FLAG_GZIP) {
Nicolas Pitre472f95f2016-07-24 11:30:26 -0400625#ifndef CONFIG_MMU
Nicolas Pitre13c3f502016-07-24 11:30:15 -0400626 result = decompress_exec(bprm, sizeof(struct flat_hdr),
627 (((char *)textpos) + sizeof(struct flat_hdr)),
Al Viro3dc20cb2013-04-13 20:31:37 -0400628 (text_len + full_data
Nicolas Pitre13c3f502016-07-24 11:30:15 -0400629 - sizeof(struct flat_hdr)),
Linus Torvalds1da177e2005-04-16 15:20:36 -0700630 0);
631 memmove((void *) datapos, (void *) realdatastart,
Al Viro3dc20cb2013-04-13 20:31:37 -0400632 full_data);
Nicolas Pitre472f95f2016-07-24 11:30:26 -0400633#else
634 /*
635 * This is used on MMU systems mainly for testing.
636 * Let's use a kernel buffer to simplify things.
637 */
638 long unz_text_len = text_len - sizeof(struct flat_hdr);
639 long unz_len = unz_text_len + full_data;
640 char *unz_data = vmalloc(unz_len);
641 if (!unz_data) {
642 result = -ENOMEM;
643 } else {
644 result = decompress_exec(bprm, sizeof(struct flat_hdr),
645 unz_data, unz_len, 0);
646 if (result == 0 &&
647 (copy_to_user((void __user *)textpos + sizeof(struct flat_hdr),
648 unz_data, unz_text_len) ||
649 copy_to_user((void __user *)datapos,
650 unz_data + unz_text_len, full_data)))
651 result = -EFAULT;
652 vfree(unz_data);
653 }
654#endif
Linus Torvalds1da177e2005-04-16 15:20:36 -0700655 } else if (flags & FLAT_FLAG_GZDATA) {
Al Viro3dc20cb2013-04-13 20:31:37 -0400656 result = read_code(bprm->file, textpos, 0, text_len);
Nicolas Pitre472f95f2016-07-24 11:30:26 -0400657 if (!IS_ERR_VALUE(result)) {
658#ifndef CONFIG_MMU
Linus Torvalds1da177e2005-04-16 15:20:36 -0700659 result = decompress_exec(bprm, text_len, (char *) datapos,
Al Viro3dc20cb2013-04-13 20:31:37 -0400660 full_data, 0);
Nicolas Pitre472f95f2016-07-24 11:30:26 -0400661#else
662 char *unz_data = vmalloc(full_data);
663 if (!unz_data) {
664 result = -ENOMEM;
665 } else {
666 result = decompress_exec(bprm, text_len,
667 unz_data, full_data, 0);
668 if (result == 0 &&
669 copy_to_user((void __user *)datapos,
670 unz_data, full_data))
671 result = -EFAULT;
672 vfree(unz_data);
673 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700674#endif
Nicolas Pitre472f95f2016-07-24 11:30:26 -0400675 }
676 } else
677#endif /* CONFIG_BINFMT_ZFLAT */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700678 {
Al Viro3dc20cb2013-04-13 20:31:37 -0400679 result = read_code(bprm->file, textpos, 0, text_len);
680 if (!IS_ERR_VALUE(result))
681 result = read_code(bprm->file, datapos,
682 ntohl(hdr->data_start),
683 full_data);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700684 }
Mike Frysinger0b8c78f2009-09-23 15:57:07 -0700685 if (IS_ERR_VALUE(result)) {
Nicolas Pitre13c3f502016-07-24 11:30:15 -0400686 ret = result;
Nicolas Pitre4adbb6a2016-07-24 11:30:16 -0400687 pr_err("Unable to read code+data+bss, errno %d\n", ret);
Al Viro7696e0c32012-05-30 01:56:23 -0400688 vm_munmap(textpos, text_len + data_len + extra +
Al Viro468138d2017-05-02 19:52:17 -0400689 MAX_SHARED_LIBS * sizeof(u32));
Andrew Mortondf889122006-05-20 15:00:01 -0700690 goto err;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700691 }
692 }
693
Nicolas Pitre13c3f502016-07-24 11:30:15 -0400694 start_code = textpos + sizeof(struct flat_hdr);
695 end_code = textpos + text_len;
696 text_len -= sizeof(struct flat_hdr); /* the real code len */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700697
698 /* The main program needs a little extra setup in the task structure */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700699 if (id == 0) {
700 current->mm->start_code = start_code;
701 current->mm->end_code = end_code;
702 current->mm->start_data = datapos;
703 current->mm->end_data = datapos + data_len;
704 /*
705 * set up the brk stuff, uses any slack left in data/bss/stack
706 * allocation. We put the brk after the bss (between the bss
707 * and stack) like other platforms.
David Howells0f3e4422009-01-08 12:04:47 +0000708 * Userspace code relies on the stack pointer starting out at
709 * an address right at the end of a page.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700710 */
711 current->mm->start_brk = datapos + data_len + bss_len;
712 current->mm->brk = (current->mm->start_brk + 3) & ~3;
Nicolas Pitre015feac2016-07-24 11:30:25 -0400713#ifndef CONFIG_MMU
David Howells0f3e4422009-01-08 12:04:47 +0000714 current->mm->context.end_brk = memp + memp_size - stack_len;
Nicolas Pitre015feac2016-07-24 11:30:25 -0400715#endif
Linus Torvalds1da177e2005-04-16 15:20:36 -0700716 }
717
Nicolas Pitre13c3f502016-07-24 11:30:15 -0400718 if (flags & FLAT_FLAG_KTRACE) {
Nicolas Pitre4adbb6a2016-07-24 11:30:16 -0400719 pr_info("Mapping is %lx, Entry point is %x, data_start is %x\n",
720 textpos, 0x00ffffff&ntohl(hdr->entry), ntohl(hdr->data_start));
721 pr_info("%s %s: TEXT=%lx-%lx DATA=%lx-%lx BSS=%lx-%lx\n",
722 id ? "Lib" : "Load", bprm->filename,
723 start_code, end_code, datapos, datapos + data_len,
724 datapos + data_len, (datapos + data_len + bss_len + 3) & ~3);
Nicolas Pitre13c3f502016-07-24 11:30:15 -0400725 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700726
727 /* Store the current module values into the global library structure */
728 libinfo->lib_list[id].start_code = start_code;
729 libinfo->lib_list[id].start_data = datapos;
730 libinfo->lib_list[id].start_brk = datapos + data_len + bss_len;
731 libinfo->lib_list[id].text_len = text_len;
732 libinfo->lib_list[id].loaded = 1;
733 libinfo->lib_list[id].entry = (0x00ffffff & ntohl(hdr->entry)) + textpos;
734 libinfo->lib_list[id].build_date = ntohl(hdr->build_date);
Nicolas Pitre13c3f502016-07-24 11:30:15 -0400735
Linus Torvalds1da177e2005-04-16 15:20:36 -0700736 /*
737 * We just load the allocations into some temporary memory to
738 * help simplify all this mumbo jumbo
739 *
740 * We've got two different sections of relocation entries.
Lucas De Marchi25985ed2011-03-30 22:57:33 -0300741 * The first is the GOT which resides at the beginning of the data segment
Linus Torvalds1da177e2005-04-16 15:20:36 -0700742 * and is terminated with a -1. This one can be relocated in place.
743 * The second is the extra relocation entries tacked after the image's
744 * data segment. These require a little more processing as the entry is
745 * really an offset into the image which contains an offset into the
746 * image.
747 */
748 if (flags & FLAT_FLAG_GOTPIC) {
Al Viro468138d2017-05-02 19:52:17 -0400749 for (rp = (u32 __user *)datapos; ; rp++) {
750 u32 addr, rp_val;
Nicolas Pitre6e572ff2016-07-24 11:30:21 -0400751 if (get_user(rp_val, rp))
752 return -EFAULT;
753 if (rp_val == 0xffffffff)
754 break;
755 if (rp_val) {
756 addr = calc_reloc(rp_val, libinfo, id, 0);
Luke Yang1ad3dcc2006-03-25 03:08:24 -0800757 if (addr == RELOC_FAILED) {
758 ret = -ENOEXEC;
Andrew Mortondf889122006-05-20 15:00:01 -0700759 goto err;
Luke Yang1ad3dcc2006-03-25 03:08:24 -0800760 }
Nicolas Pitre6e572ff2016-07-24 11:30:21 -0400761 if (put_user(addr, rp))
762 return -EFAULT;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700763 }
764 }
765 }
766
767 /*
768 * Now run through the relocation entries.
769 * We've got to be careful here as C++ produces relocatable zero
770 * entries in the constructor and destructor tables which are then
771 * tested for being not zero (which will always occur unless we're
772 * based from address zero). This causes an endless loop as __start
773 * is at zero. The solution used is to not relocate zero addresses.
774 * This has the negative side effect of not allowing a global data
775 * reference to be statically initialised to _stext (I've moved
776 * __start to address 4 so that is okay).
777 */
778 if (rev > OLD_FLAT_VERSION) {
Al Viro468138d2017-05-02 19:52:17 -0400779 u32 __maybe_unused persistent = 0;
Nicolas Pitre13c3f502016-07-24 11:30:15 -0400780 for (i = 0; i < relocs; i++) {
Al Viro468138d2017-05-02 19:52:17 -0400781 u32 addr, relval;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700782
Nicolas Pitre13c3f502016-07-24 11:30:15 -0400783 /*
784 * Get the address of the pointer to be
785 * relocated (of course, the address has to be
786 * relocated first).
787 */
Nicolas Pitre6e572ff2016-07-24 11:30:21 -0400788 if (get_user(relval, reloc + i))
789 return -EFAULT;
790 relval = ntohl(relval);
Nicolas Pitre13c3f502016-07-24 11:30:15 -0400791 if (flat_set_persistent(relval, &persistent))
Bernd Schmidtf9720202007-10-03 23:41:43 +0800792 continue;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700793 addr = flat_get_relocate_addr(relval);
Al Viro468138d2017-05-02 19:52:17 -0400794 rp = (u32 __user *)calc_reloc(addr, libinfo, id, 1);
795 if (rp == (u32 __user *)RELOC_FAILED) {
Luke Yang1ad3dcc2006-03-25 03:08:24 -0800796 ret = -ENOEXEC;
Andrew Mortondf889122006-05-20 15:00:01 -0700797 goto err;
Luke Yang1ad3dcc2006-03-25 03:08:24 -0800798 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700799
800 /* Get the pointer's value. */
Al Viro468138d2017-05-02 19:52:17 -0400801 ret = flat_get_addr_from_rp(rp, relval, flags,
802 &addr, &persistent);
803 if (unlikely(ret))
804 goto err;
805
Linus Torvalds1da177e2005-04-16 15:20:36 -0700806 if (addr != 0) {
807 /*
808 * Do the relocation. PIC relocs in the data section are
809 * already in target order
810 */
811 if ((flags & FLAT_FLAG_GOTPIC) == 0)
812 addr = ntohl(addr);
813 addr = calc_reloc(addr, libinfo, id, 0);
Luke Yang1ad3dcc2006-03-25 03:08:24 -0800814 if (addr == RELOC_FAILED) {
815 ret = -ENOEXEC;
Andrew Mortondf889122006-05-20 15:00:01 -0700816 goto err;
Luke Yang1ad3dcc2006-03-25 03:08:24 -0800817 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700818
819 /* Write back the relocated pointer. */
Al Viro468138d2017-05-02 19:52:17 -0400820 ret = flat_put_addr_at_rp(rp, addr, relval);
821 if (unlikely(ret))
822 goto err;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700823 }
824 }
825 } else {
Nicolas Pitre1b2ce442016-07-24 11:30:22 -0400826 for (i = 0; i < relocs; i++) {
Al Viro468138d2017-05-02 19:52:17 -0400827 u32 relval;
Nicolas Pitre1b2ce442016-07-24 11:30:22 -0400828 if (get_user(relval, reloc + i))
829 return -EFAULT;
830 relval = ntohl(relval);
831 old_reloc(relval);
832 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700833 }
Nicolas Pitre13c3f502016-07-24 11:30:15 -0400834
Linus Torvalds1da177e2005-04-16 15:20:36 -0700835 flush_icache_range(start_code, end_code);
836
837 /* zero the BSS, BRK and stack areas */
Nicolas Pitre467aa142016-07-24 11:30:23 -0400838 if (clear_user((void __user *)(datapos + data_len), bss_len +
839 (memp + memp_size - stack_len - /* end brk */
840 libinfo->lib_list[id].start_brk) + /* start brk */
841 stack_len))
842 return -EFAULT;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700843
844 return 0;
Luke Yang1ad3dcc2006-03-25 03:08:24 -0800845err:
846 return ret;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700847}
848
849
850/****************************************************************************/
851#ifdef CONFIG_BINFMT_SHARED_FLAT
852
853/*
854 * Load a shared library into memory. The library gets its own data
855 * segment (including bss) but not argv/argc/environ.
856 */
857
858static int load_flat_shared_library(int id, struct lib_info *libs)
859{
860 struct linux_binprm bprm;
861 int res;
862 char buf[16];
863
David Howells3a852d32011-04-28 16:26:38 +0100864 memset(&bprm, 0, sizeof(bprm));
865
Linus Torvalds1da177e2005-04-16 15:20:36 -0700866 /* Create the file name */
867 sprintf(buf, "/lib/lib%d.so", id);
868
869 /* Open the file up */
870 bprm.filename = buf;
871 bprm.file = open_exec(bprm.filename);
872 res = PTR_ERR(bprm.file);
873 if (IS_ERR(bprm.file))
874 return res;
875
Linus Torvalds34406252009-08-06 15:09:34 -0700876 bprm.cred = prepare_exec_creds();
877 res = -ENOMEM;
878 if (!bprm.cred)
879 goto out;
880
David Howells3a852d32011-04-28 16:26:38 +0100881 /* We don't really care about recalculating credentials at this point
882 * as we're past the point of no return and are dealing with shared
883 * libraries.
884 */
885 bprm.cred_prepared = 1;
886
Linus Torvalds1da177e2005-04-16 15:20:36 -0700887 res = prepare_binprm(&bprm);
888
Arnd Bergmann287980e2016-05-27 23:23:25 +0200889 if (!res)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700890 res = load_flat_file(&bprm, libs, id, NULL);
Linus Torvalds34406252009-08-06 15:09:34 -0700891
892 abort_creds(bprm.cred);
893
894out:
895 allow_write_access(bprm.file);
896 fput(bprm.file);
897
Nicolas Pitre13c3f502016-07-24 11:30:15 -0400898 return res;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700899}
900
901#endif /* CONFIG_BINFMT_SHARED_FLAT */
902/****************************************************************************/
903
904/*
905 * These are the functions used to load flat style executables and shared
906 * libraries. There is no binary dependent code anywhere else.
907 */
908
Nicolas Pitre13c3f502016-07-24 11:30:15 -0400909static int load_flat_binary(struct linux_binprm *bprm)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700910{
911 struct lib_info libinfo;
Al Viro71613c32012-10-20 22:00:48 -0400912 struct pt_regs *regs = current_pt_regs();
Nicolas Pitre015feac2016-07-24 11:30:25 -0400913 unsigned long stack_len = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700914 unsigned long start_addr;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700915 int res;
916 int i, j;
917
918 memset(&libinfo, 0, sizeof(libinfo));
Nicolas Pitre13c3f502016-07-24 11:30:15 -0400919
Linus Torvalds1da177e2005-04-16 15:20:36 -0700920 /*
921 * We have to add the size of our arguments to our stack size
922 * otherwise it's too easy for users to create stack overflows
923 * by passing in a huge argument list. And yes, we have to be
924 * pedantic and include space for the argv/envp array as it may have
925 * a lot of entries.
926 */
Nicolas Pitre015feac2016-07-24 11:30:25 -0400927#ifndef CONFIG_MMU
928 stack_len += PAGE_SIZE * MAX_ARG_PAGES - bprm->p; /* the strings */
929#endif
Nicolas Pitrea97d1572016-07-24 11:30:20 -0400930 stack_len += (bprm->argc + 1) * sizeof(char *); /* the argv array */
931 stack_len += (bprm->envc + 1) * sizeof(char *); /* the envp array */
932 stack_len = ALIGN(stack_len, FLAT_STACK_ALIGN);
Nicolas Pitre13c3f502016-07-24 11:30:15 -0400933
Linus Torvalds1da177e2005-04-16 15:20:36 -0700934 res = load_flat_file(bprm, &libinfo, 0, &stack_len);
Arnd Bergmann287980e2016-05-27 23:23:25 +0200935 if (res < 0)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700936 return res;
Nicolas Pitre13c3f502016-07-24 11:30:15 -0400937
Linus Torvalds1da177e2005-04-16 15:20:36 -0700938 /* Update data segment pointers for all libraries */
Nicolas Pitreaf521f92016-07-24 11:30:24 -0400939 for (i = 0; i < MAX_SHARED_LIBS; i++) {
940 if (!libinfo.lib_list[i].loaded)
941 continue;
942 for (j = 0; j < MAX_SHARED_LIBS; j++) {
943 unsigned long val = libinfo.lib_list[j].loaded ?
944 libinfo.lib_list[j].start_data : UNLOADED_LIB;
945 unsigned long __user *p = (unsigned long __user *)
946 libinfo.lib_list[i].start_data;
947 p -= j + 1;
948 if (put_user(val, p))
949 return -EFAULT;
950 }
951 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700952
David Howellsa6f76f22008-11-14 10:39:24 +1100953 install_exec_creds(bprm);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700954
955 set_binfmt(&flat_format);
956
Nicolas Pitre015feac2016-07-24 11:30:25 -0400957#ifdef CONFIG_MMU
958 res = setup_arg_pages(bprm, STACK_TOP, EXSTACK_DEFAULT);
959 if (!res)
960 res = create_flat_tables(bprm, bprm->p);
961#else
Nicolas Pitrea97d1572016-07-24 11:30:20 -0400962 /* Stash our initial stack pointer into the mm structure */
963 current->mm->start_stack =
964 ((current->mm->context.end_brk + stack_len + 3) & ~3) - 4;
965 pr_debug("sp=%lx\n", current->mm->start_stack);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700966
Nicolas Pitre687fd772016-07-24 11:30:19 -0400967 /* copy the arg pages onto the stack */
Nicolas Pitrea97d1572016-07-24 11:30:20 -0400968 res = transfer_args_to_stack(bprm, &current->mm->start_stack);
969 if (!res)
970 res = create_flat_tables(bprm, current->mm->start_stack);
Nicolas Pitre015feac2016-07-24 11:30:25 -0400971#endif
Nicolas Pitre687fd772016-07-24 11:30:19 -0400972 if (res)
973 return res;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700974
Linus Torvalds1da177e2005-04-16 15:20:36 -0700975 /* Fake some return addresses to ensure the call chain will
976 * initialise library in order for us. We are required to call
977 * lib 1 first, then 2, ... and finally the main program (id 0).
978 */
979 start_addr = libinfo.lib_list[0].entry;
980
981#ifdef CONFIG_BINFMT_SHARED_FLAT
Nicolas Pitre13c3f502016-07-24 11:30:15 -0400982 for (i = MAX_SHARED_LIBS-1; i > 0; i--) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700983 if (libinfo.lib_list[i].loaded) {
984 /* Push previos first to call address */
Nicolas Pitrea97d1572016-07-24 11:30:20 -0400985 unsigned long __user *sp;
986 current->mm->start_stack -= sizeof(unsigned long);
987 sp = (unsigned long __user *)current->mm->start_stack;
988 __put_user(start_addr, sp);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700989 start_addr = libinfo.lib_list[i].entry;
990 }
991 }
992#endif
Nicolas Pitre13c3f502016-07-24 11:30:15 -0400993
Takashi YOSHII74c27c42008-08-11 20:10:54 +0900994#ifdef FLAT_PLAT_INIT
995 FLAT_PLAT_INIT(regs);
996#endif
Nicolas Pitre13c3f502016-07-24 11:30:15 -0400997
Nicolas Pitre4adbb6a2016-07-24 11:30:16 -0400998 pr_debug("start_thread(regs=0x%p, entry=0x%lx, start_stack=0x%lx)\n",
999 regs, start_addr, current->mm->start_stack);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001000 start_thread(regs, start_addr, current->mm->start_stack);
1001
Linus Torvalds1da177e2005-04-16 15:20:36 -07001002 return 0;
1003}
1004
1005/****************************************************************************/
1006
1007static int __init init_flat_binfmt(void)
1008{
Al Viro8fc3dc52012-03-17 03:05:16 -04001009 register_binfmt(&flat_format);
1010 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001011}
Linus Torvalds1da177e2005-04-16 15:20:36 -07001012core_initcall(init_flat_binfmt);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001013
1014/****************************************************************************/