blob: 2edcefc0a2949af4d302b9060885a4e8bba79d7c [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
179static int decompress_exec(
180 struct linux_binprm *bprm,
181 unsigned long offset,
182 char *dst,
183 long len,
184 int fd)
185{
186 unsigned char *buf;
187 z_stream strm;
188 loff_t fpos;
189 int ret, retval;
190
Nicolas Pitre4adbb6a2016-07-24 11:30:16 -0400191 pr_debug("decompress_exec(offset=%lx,buf=%p,len=%lx)\n", offset, dst, len);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700192
193 memset(&strm, 0, sizeof(strm));
194 strm.workspace = kmalloc(zlib_inflate_workspacesize(), GFP_KERNEL);
195 if (strm.workspace == NULL) {
Nicolas Pitre4adbb6a2016-07-24 11:30:16 -0400196 pr_debug("no memory for decompress workspace\n");
Linus Torvalds1da177e2005-04-16 15:20:36 -0700197 return -ENOMEM;
198 }
199 buf = kmalloc(LBUFSIZE, GFP_KERNEL);
200 if (buf == NULL) {
Nicolas Pitre4adbb6a2016-07-24 11:30:16 -0400201 pr_debug("no memory for read buffer\n");
Linus Torvalds1da177e2005-04-16 15:20:36 -0700202 retval = -ENOMEM;
203 goto out_free;
204 }
205
206 /* Read in first chunk of data and parse gzip header. */
207 fpos = offset;
Al Viro3dc20cb2013-04-13 20:31:37 -0400208 ret = kernel_read(bprm->file, offset, buf, LBUFSIZE);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700209
210 strm.next_in = buf;
211 strm.avail_in = ret;
212 strm.total_in = 0;
Al Viro3dc20cb2013-04-13 20:31:37 -0400213 fpos += ret;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700214
215 retval = -ENOEXEC;
216
217 /* Check minimum size -- gzip header */
218 if (ret < 10) {
Nicolas Pitre4adbb6a2016-07-24 11:30:16 -0400219 pr_debug("file too small?\n");
Linus Torvalds1da177e2005-04-16 15:20:36 -0700220 goto out_free_buf;
221 }
222
223 /* Check gzip magic number */
224 if ((buf[0] != 037) || ((buf[1] != 0213) && (buf[1] != 0236))) {
Nicolas Pitre4adbb6a2016-07-24 11:30:16 -0400225 pr_debug("unknown compression magic?\n");
Linus Torvalds1da177e2005-04-16 15:20:36 -0700226 goto out_free_buf;
227 }
228
229 /* Check gzip method */
230 if (buf[2] != 8) {
Nicolas Pitre4adbb6a2016-07-24 11:30:16 -0400231 pr_debug("unknown compression method?\n");
Linus Torvalds1da177e2005-04-16 15:20:36 -0700232 goto out_free_buf;
233 }
234 /* Check gzip flags */
235 if ((buf[3] & ENCRYPTED) || (buf[3] & CONTINUATION) ||
236 (buf[3] & RESERVED)) {
Nicolas Pitre4adbb6a2016-07-24 11:30:16 -0400237 pr_debug("unknown flags?\n");
Linus Torvalds1da177e2005-04-16 15:20:36 -0700238 goto out_free_buf;
239 }
240
241 ret = 10;
242 if (buf[3] & EXTRA_FIELD) {
243 ret += 2 + buf[10] + (buf[11] << 8);
Nicolas Pitre13c3f502016-07-24 11:30:15 -0400244 if (unlikely(ret >= LBUFSIZE)) {
Nicolas Pitre4adbb6a2016-07-24 11:30:16 -0400245 pr_debug("buffer overflow (EXTRA)?\n");
Linus Torvalds1da177e2005-04-16 15:20:36 -0700246 goto out_free_buf;
247 }
248 }
249 if (buf[3] & ORIG_NAME) {
Volodymyr G. Lukiianykf4cfb182008-10-15 22:01:15 -0700250 while (ret < LBUFSIZE && buf[ret++] != 0)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700251 ;
Nicolas Pitre13c3f502016-07-24 11:30:15 -0400252 if (unlikely(ret == LBUFSIZE)) {
Nicolas Pitre4adbb6a2016-07-24 11:30:16 -0400253 pr_debug("buffer overflow (ORIG_NAME)?\n");
Linus Torvalds1da177e2005-04-16 15:20:36 -0700254 goto out_free_buf;
255 }
256 }
257 if (buf[3] & COMMENT) {
Volodymyr G. Lukiianykf4cfb182008-10-15 22:01:15 -0700258 while (ret < LBUFSIZE && buf[ret++] != 0)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700259 ;
Nicolas Pitre13c3f502016-07-24 11:30:15 -0400260 if (unlikely(ret == LBUFSIZE)) {
Nicolas Pitre4adbb6a2016-07-24 11:30:16 -0400261 pr_debug("buffer overflow (COMMENT)?\n");
Linus Torvalds1da177e2005-04-16 15:20:36 -0700262 goto out_free_buf;
263 }
264 }
265
266 strm.next_in += ret;
267 strm.avail_in -= ret;
268
269 strm.next_out = dst;
270 strm.avail_out = len;
271 strm.total_out = 0;
272
273 if (zlib_inflateInit2(&strm, -MAX_WBITS) != Z_OK) {
Nicolas Pitre4adbb6a2016-07-24 11:30:16 -0400274 pr_debug("zlib init failed?\n");
Linus Torvalds1da177e2005-04-16 15:20:36 -0700275 goto out_free_buf;
276 }
277
278 while ((ret = zlib_inflate(&strm, Z_NO_FLUSH)) == Z_OK) {
Al Viro3dc20cb2013-04-13 20:31:37 -0400279 ret = kernel_read(bprm->file, fpos, buf, LBUFSIZE);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700280 if (ret <= 0)
281 break;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700282 len -= ret;
283
284 strm.next_in = buf;
285 strm.avail_in = ret;
286 strm.total_in = 0;
Al Viro3dc20cb2013-04-13 20:31:37 -0400287 fpos += ret;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700288 }
289
290 if (ret < 0) {
Nicolas Pitre4adbb6a2016-07-24 11:30:16 -0400291 pr_debug("decompression failed (%d), %s\n",
Linus Torvalds1da177e2005-04-16 15:20:36 -0700292 ret, strm.msg);
293 goto out_zlib;
294 }
295
296 retval = 0;
297out_zlib:
298 zlib_inflateEnd(&strm);
299out_free_buf:
300 kfree(buf);
301out_free:
302 kfree(strm.workspace);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700303 return retval;
304}
305
306#endif /* CONFIG_BINFMT_ZFLAT */
307
308/****************************************************************************/
309
310static unsigned long
311calc_reloc(unsigned long r, struct lib_info *p, int curid, int internalp)
312{
313 unsigned long addr;
314 int id;
315 unsigned long start_brk;
316 unsigned long start_data;
317 unsigned long text_len;
318 unsigned long start_code;
319
320#ifdef CONFIG_BINFMT_SHARED_FLAT
321 if (r == 0)
322 id = curid; /* Relocs of 0 are always self referring */
323 else {
324 id = (r >> 24) & 0xff; /* Find ID for this reloc */
325 r &= 0x00ffffff; /* Trim ID off here */
326 }
327 if (id >= MAX_SHARED_LIBS) {
Nicolas Pitre4adbb6a2016-07-24 11:30:16 -0400328 pr_err("reference 0x%lx to shared library %d", r, id);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700329 goto failed;
330 }
331 if (curid != id) {
332 if (internalp) {
Nicolas Pitre4adbb6a2016-07-24 11:30:16 -0400333 pr_err("reloc address 0x%lx not in same module "
334 "(%d != %d)", r, curid, id);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700335 goto failed;
Nicolas Pitre13c3f502016-07-24 11:30:15 -0400336 } else if (!p->lib_list[id].loaded &&
337 load_flat_shared_library(id, p) < 0) {
Nicolas Pitre4adbb6a2016-07-24 11:30:16 -0400338 pr_err("failed to load library %d", id);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700339 goto failed;
340 }
341 /* Check versioning information (i.e. time stamps) */
342 if (p->lib_list[id].build_date && p->lib_list[curid].build_date &&
343 p->lib_list[curid].build_date < p->lib_list[id].build_date) {
Nicolas Pitre4adbb6a2016-07-24 11:30:16 -0400344 pr_err("library %d is younger than %d", id, curid);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700345 goto failed;
346 }
347 }
348#else
349 id = 0;
350#endif
351
352 start_brk = p->lib_list[id].start_brk;
353 start_data = p->lib_list[id].start_data;
354 start_code = p->lib_list[id].start_code;
355 text_len = p->lib_list[id].text_len;
356
357 if (!flat_reloc_valid(r, start_brk - start_data + text_len)) {
Nicolas Pitre4adbb6a2016-07-24 11:30:16 -0400358 pr_err("reloc outside program 0x%lx (0 - 0x%lx/0x%lx)",
Nicolas Pitre13c3f502016-07-24 11:30:15 -0400359 r, start_brk-start_data+text_len, text_len);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700360 goto failed;
361 }
362
363 if (r < text_len) /* In text segment */
364 addr = r + start_code;
365 else /* In data segment */
366 addr = r - text_len + start_data;
367
368 /* Range checked already above so doing the range tests is redundant...*/
Nicolas Pitre13c3f502016-07-24 11:30:15 -0400369 return addr;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700370
371failed:
Nicolas Pitre4adbb6a2016-07-24 11:30:16 -0400372 pr_cont(", killing %s!\n", current->comm);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700373 send_sig(SIGSEGV, current, 0);
374
375 return RELOC_FAILED;
376}
377
378/****************************************************************************/
379
Axel Lin34303432014-06-04 16:12:15 -0700380static void old_reloc(unsigned long rl)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700381{
Nicolas Pitre13c3f502016-07-24 11:30:15 -0400382 static const char *segment[] = { "TEXT", "DATA", "BSS", "*UNKNOWN*" };
Linus Torvalds1da177e2005-04-16 15:20:36 -0700383 flat_v2_reloc_t r;
Nicolas Pitre1b2ce442016-07-24 11:30:22 -0400384 unsigned long __user *ptr;
385 unsigned long val;
Nicolas Pitre13c3f502016-07-24 11:30:15 -0400386
Linus Torvalds1da177e2005-04-16 15:20:36 -0700387 r.value = rl;
388#if defined(CONFIG_COLDFIRE)
Nicolas Pitre1b2ce442016-07-24 11:30:22 -0400389 ptr = (unsigned long __user *)(current->mm->start_code + r.reloc.offset);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700390#else
Nicolas Pitre1b2ce442016-07-24 11:30:22 -0400391 ptr = (unsigned long __user *)(current->mm->start_data + r.reloc.offset);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700392#endif
Nicolas Pitre1b2ce442016-07-24 11:30:22 -0400393 get_user(val, ptr);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700394
Nicolas Pitre4adbb6a2016-07-24 11:30:16 -0400395 pr_debug("Relocation of variable at DATASEG+%x "
396 "(address %p, currently %lx) into segment %s\n",
Nicolas Pitre1b2ce442016-07-24 11:30:22 -0400397 r.reloc.offset, ptr, val, segment[r.reloc.type]);
Nicolas Pitre13c3f502016-07-24 11:30:15 -0400398
Linus Torvalds1da177e2005-04-16 15:20:36 -0700399 switch (r.reloc.type) {
400 case OLD_FLAT_RELOC_TYPE_TEXT:
Nicolas Pitre1b2ce442016-07-24 11:30:22 -0400401 val += current->mm->start_code;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700402 break;
403 case OLD_FLAT_RELOC_TYPE_DATA:
Nicolas Pitre1b2ce442016-07-24 11:30:22 -0400404 val += current->mm->start_data;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700405 break;
406 case OLD_FLAT_RELOC_TYPE_BSS:
Nicolas Pitre1b2ce442016-07-24 11:30:22 -0400407 val += current->mm->end_data;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700408 break;
409 default:
Nicolas Pitre4adbb6a2016-07-24 11:30:16 -0400410 pr_err("Unknown relocation type=%x\n", r.reloc.type);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700411 break;
412 }
Nicolas Pitre1b2ce442016-07-24 11:30:22 -0400413 put_user(val, ptr);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700414
Nicolas Pitre1b2ce442016-07-24 11:30:22 -0400415 pr_debug("Relocation became %lx\n", val);
Nicolas Pitre13c3f502016-07-24 11:30:15 -0400416}
Linus Torvalds1da177e2005-04-16 15:20:36 -0700417
418/****************************************************************************/
419
Nicolas Pitre13c3f502016-07-24 11:30:15 -0400420static int load_flat_file(struct linux_binprm *bprm,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700421 struct lib_info *libinfo, int id, unsigned long *extra_stack)
422{
Nicolas Pitre13c3f502016-07-24 11:30:15 -0400423 struct flat_hdr *hdr;
424 unsigned long textpos, datapos, realdatastart;
425 unsigned long text_len, data_len, bss_len, stack_len, full_data, flags;
426 unsigned long len, memp, memp_size, extra, rlim;
Nicolas Pitre6e572ff2016-07-24 11:30:21 -0400427 unsigned long __user *reloc, *rp;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700428 struct inode *inode;
Nicolas Pitre13c3f502016-07-24 11:30:15 -0400429 int i, rev, relocs;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700430 loff_t fpos;
431 unsigned long start_code, end_code;
Nicolas Pitre13c3f502016-07-24 11:30:15 -0400432 ssize_t result;
Luke Yang1ad3dcc2006-03-25 03:08:24 -0800433 int ret;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700434
435 hdr = ((struct flat_hdr *) bprm->buf); /* exec-header */
Al Viro496ad9a2013-01-23 17:07:38 -0500436 inode = file_inode(bprm->file);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700437
438 text_len = ntohl(hdr->data_start);
439 data_len = ntohl(hdr->data_end) - ntohl(hdr->data_start);
440 bss_len = ntohl(hdr->bss_end) - ntohl(hdr->data_end);
441 stack_len = ntohl(hdr->stack_size);
442 if (extra_stack) {
443 stack_len += *extra_stack;
444 *extra_stack = stack_len;
445 }
446 relocs = ntohl(hdr->reloc_count);
447 flags = ntohl(hdr->flags);
448 rev = ntohl(hdr->rev);
Al Viro3dc20cb2013-04-13 20:31:37 -0400449 full_data = data_len + relocs * sizeof(unsigned long);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700450
Greg Ungerer845884d2006-01-10 16:59:37 +1000451 if (strncmp(hdr->magic, "bFLT", 4)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700452 /*
Mike Frysingere2a366d2008-02-14 19:31:29 -0800453 * Previously, here was a printk to tell people
454 * "BINFMT_FLAT: bad header magic".
455 * But for the kernel which also use ELF FD-PIC format, this
456 * error message is confusing.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700457 * because a lot of people do not manage to produce good
Linus Torvalds1da177e2005-04-16 15:20:36 -0700458 */
Luke Yang1ad3dcc2006-03-25 03:08:24 -0800459 ret = -ENOEXEC;
460 goto err;
Greg Ungerer845884d2006-01-10 16:59:37 +1000461 }
462
463 if (flags & FLAT_FLAG_KTRACE)
Nicolas Pitre4adbb6a2016-07-24 11:30:16 -0400464 pr_info("Loading file: %s\n", bprm->filename);
Greg Ungerer845884d2006-01-10 16:59:37 +1000465
466 if (rev != FLAT_VERSION && rev != OLD_FLAT_VERSION) {
Nicolas Pitre4adbb6a2016-07-24 11:30:16 -0400467 pr_err("bad flat file version 0x%x (supported 0x%lx and 0x%lx)\n",
468 rev, FLAT_VERSION, OLD_FLAT_VERSION);
Luke Yang1ad3dcc2006-03-25 03:08:24 -0800469 ret = -ENOEXEC;
470 goto err;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700471 }
Nicolas Pitre13c3f502016-07-24 11:30:15 -0400472
Linus Torvalds1da177e2005-04-16 15:20:36 -0700473 /* Don't allow old format executables to use shared libraries */
474 if (rev == OLD_FLAT_VERSION && id != 0) {
Nicolas Pitre4adbb6a2016-07-24 11:30:16 -0400475 pr_err("shared libraries are not available before rev 0x%lx\n",
476 FLAT_VERSION);
Luke Yang1ad3dcc2006-03-25 03:08:24 -0800477 ret = -ENOEXEC;
478 goto err;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700479 }
480
481 /*
Nicolas Pitrec995ee22016-07-24 11:30:17 -0400482 * Make sure the header params are sane.
483 * 28 bits (256 MB) is way more than reasonable in this case.
484 * If some top bits are set we have probable binary corruption.
485 */
486 if ((text_len | data_len | bss_len | stack_len | full_data) >> 28) {
487 pr_err("bad header\n");
488 ret = -ENOEXEC;
489 goto err;
490 }
491
492 /*
Linus Torvalds1da177e2005-04-16 15:20:36 -0700493 * fix up the flags for the older format, there were all kinds
494 * of endian hacks, this only works for the simple cases
495 */
496 if (rev == OLD_FLAT_VERSION && flat_old_ram_flag(flags))
497 flags = FLAT_FLAG_RAM;
498
499#ifndef CONFIG_BINFMT_ZFLAT
500 if (flags & (FLAT_FLAG_GZIP|FLAT_FLAG_GZDATA)) {
Nicolas Pitre4adbb6a2016-07-24 11:30:16 -0400501 pr_err("Support for ZFLAT executables is not enabled.\n");
Luke Yang1ad3dcc2006-03-25 03:08:24 -0800502 ret = -ENOEXEC;
503 goto err;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700504 }
505#endif
506
507 /*
508 * Check initial limits. This avoids letting people circumvent
509 * size limits imposed on them by creating programs with large
510 * arrays in the data or bss.
511 */
Jiri Slabyd554ed892010-03-05 13:42:42 -0800512 rlim = rlimit(RLIMIT_DATA);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700513 if (rlim >= RLIM_INFINITY)
514 rlim = ~0;
Luke Yang1ad3dcc2006-03-25 03:08:24 -0800515 if (data_len + bss_len > rlim) {
516 ret = -ENOMEM;
517 goto err;
518 }
519
Linus Torvalds1da177e2005-04-16 15:20:36 -0700520 /* Flush all traces of the currently running executable */
521 if (id == 0) {
Nicolas Pitre13c3f502016-07-24 11:30:15 -0400522 ret = flush_old_exec(bprm);
523 if (ret)
Andrew Mortondf889122006-05-20 15:00:01 -0700524 goto err;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700525
526 /* OK, This is the point of no return */
Malcolm Parsonsfcc18e82006-06-26 11:49:41 +1000527 set_personality(PER_LINUX_32BIT);
Linus Torvalds221af7f2010-01-28 22:14:42 -0800528 setup_new_exec(bprm);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700529 }
530
531 /*
532 * calculate the extra space we need to map in
533 */
Andrew Morton0e647c02007-10-16 23:27:26 -0700534 extra = max_t(unsigned long, bss_len + stack_len,
535 relocs * sizeof(unsigned long));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700536
537 /*
538 * there are a couple of cases here, the separate code/data
539 * case, and then the fully copied to RAM case which lumps
540 * it all together.
541 */
Nicolas Pitre015feac2016-07-24 11:30:25 -0400542 if (!IS_ENABLED(CONFIG_MMU) && !(flags & (FLAT_FLAG_RAM|FLAT_FLAG_GZIP))) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700543 /*
544 * this should give us a ROM ptr, but if it doesn't we don't
545 * really care
546 */
Nicolas Pitre4adbb6a2016-07-24 11:30:16 -0400547 pr_debug("ROM mapping of file (we hope)\n");
Linus Torvalds1da177e2005-04-16 15:20:36 -0700548
Linus Torvalds6be5ceb2012-04-20 17:13:58 -0700549 textpos = vm_mmap(bprm->file, 0, text_len, PROT_READ|PROT_EXEC,
Matt Helsley925d1c42008-04-29 01:01:36 -0700550 MAP_PRIVATE|MAP_EXECUTABLE, 0);
Mike Frysinger0b8c78f2009-09-23 15:57:07 -0700551 if (!textpos || IS_ERR_VALUE(textpos)) {
Luke Yang1ad3dcc2006-03-25 03:08:24 -0800552 ret = textpos;
Nicolas Pitre13c3f502016-07-24 11:30:15 -0400553 if (!textpos)
554 ret = -ENOMEM;
Nicolas Pitre4adbb6a2016-07-24 11:30:16 -0400555 pr_err("Unable to mmap process text, errno %d\n", ret);
Andrew Mortondf889122006-05-20 15:00:01 -0700556 goto err;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700557 }
558
Greg Ungerer72613e5f2007-02-07 12:03:08 +1000559 len = data_len + extra + MAX_SHARED_LIBS * sizeof(unsigned long);
David Howells0f3e4422009-01-08 12:04:47 +0000560 len = PAGE_ALIGN(len);
Nicolas Pitre13c3f502016-07-24 11:30:15 -0400561 realdatastart = vm_mmap(NULL, 0, len,
Greg Ungerer72613e5f2007-02-07 12:03:08 +1000562 PROT_READ|PROT_WRITE|PROT_EXEC, MAP_PRIVATE, 0);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700563
Mike Frysinger0b8c78f2009-09-23 15:57:07 -0700564 if (realdatastart == 0 || IS_ERR_VALUE(realdatastart)) {
Luke Yang1ad3dcc2006-03-25 03:08:24 -0800565 ret = realdatastart;
Nicolas Pitre13c3f502016-07-24 11:30:15 -0400566 if (!realdatastart)
567 ret = -ENOMEM;
Nicolas Pitre4adbb6a2016-07-24 11:30:16 -0400568 pr_err("Unable to allocate RAM for process data, "
Nicolas Pitre13c3f502016-07-24 11:30:15 -0400569 "errno %d\n", ret);
570 vm_munmap(textpos, text_len);
Andrew Mortondf889122006-05-20 15:00:01 -0700571 goto err;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700572 }
Oskar Schirmerc3dc5be2009-05-28 14:34:31 -0700573 datapos = ALIGN(realdatastart +
574 MAX_SHARED_LIBS * sizeof(unsigned long),
575 FLAT_DATA_ALIGN);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700576
Nicolas Pitre4adbb6a2016-07-24 11:30:16 -0400577 pr_debug("Allocated data+bss+stack (%ld bytes): %lx\n",
578 data_len + bss_len + stack_len, datapos);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700579
580 fpos = ntohl(hdr->data_start);
581#ifdef CONFIG_BINFMT_ZFLAT
582 if (flags & FLAT_FLAG_GZDATA) {
Nicolas Pitre13c3f502016-07-24 11:30:15 -0400583 result = decompress_exec(bprm, fpos, (char *)datapos,
Al Viro3dc20cb2013-04-13 20:31:37 -0400584 full_data, 0);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700585 } else
586#endif
587 {
Al Viro3dc20cb2013-04-13 20:31:37 -0400588 result = read_code(bprm->file, datapos, fpos,
589 full_data);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700590 }
Mike Frysinger0b8c78f2009-09-23 15:57:07 -0700591 if (IS_ERR_VALUE(result)) {
Nicolas Pitre13c3f502016-07-24 11:30:15 -0400592 ret = result;
Nicolas Pitre4adbb6a2016-07-24 11:30:16 -0400593 pr_err("Unable to read data+bss, errno %d\n", ret);
Al Viro7696e0c32012-05-30 01:56:23 -0400594 vm_munmap(textpos, text_len);
595 vm_munmap(realdatastart, len);
Andrew Mortondf889122006-05-20 15:00:01 -0700596 goto err;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700597 }
598
Nicolas Pitre6e572ff2016-07-24 11:30:21 -0400599 reloc = (unsigned long __user *)
Nicolas Pitre13c3f502016-07-24 11:30:15 -0400600 (datapos + (ntohl(hdr->reloc_start) - text_len));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700601 memp = realdatastart;
David Howells0f3e4422009-01-08 12:04:47 +0000602 memp_size = len;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700603 } else {
604
Greg Ungerer72613e5f2007-02-07 12:03:08 +1000605 len = text_len + data_len + extra + MAX_SHARED_LIBS * sizeof(unsigned long);
David Howells0f3e4422009-01-08 12:04:47 +0000606 len = PAGE_ALIGN(len);
Nicolas Pitre13c3f502016-07-24 11:30:15 -0400607 textpos = vm_mmap(NULL, 0, len,
Greg Ungerer72613e5f2007-02-07 12:03:08 +1000608 PROT_READ | PROT_EXEC | PROT_WRITE, MAP_PRIVATE, 0);
Greg Ungerer72613e5f2007-02-07 12:03:08 +1000609
Mike Frysinger0b8c78f2009-09-23 15:57:07 -0700610 if (!textpos || IS_ERR_VALUE(textpos)) {
Luke Yang1ad3dcc2006-03-25 03:08:24 -0800611 ret = textpos;
Nicolas Pitre13c3f502016-07-24 11:30:15 -0400612 if (!textpos)
613 ret = -ENOMEM;
Nicolas Pitre4adbb6a2016-07-24 11:30:16 -0400614 pr_err("Unable to allocate RAM for process text/data, "
Nicolas Pitre13c3f502016-07-24 11:30:15 -0400615 "errno %d\n", ret);
Andrew Mortondf889122006-05-20 15:00:01 -0700616 goto err;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700617 }
618
619 realdatastart = textpos + ntohl(hdr->data_start);
Oskar Schirmerc3dc5be2009-05-28 14:34:31 -0700620 datapos = ALIGN(realdatastart +
621 MAX_SHARED_LIBS * sizeof(unsigned long),
622 FLAT_DATA_ALIGN);
623
Nicolas Pitre6e572ff2016-07-24 11:30:21 -0400624 reloc = (unsigned long __user *)
Oskar Schirmerc3dc5be2009-05-28 14:34:31 -0700625 (datapos + (ntohl(hdr->reloc_start) - text_len));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700626 memp = textpos;
David Howells0f3e4422009-01-08 12:04:47 +0000627 memp_size = len;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700628#ifdef CONFIG_BINFMT_ZFLAT
629 /*
630 * load it all in and treat it like a RAM load from now on
631 */
632 if (flags & FLAT_FLAG_GZIP) {
Nicolas Pitre472f95f2016-07-24 11:30:26 -0400633#ifndef CONFIG_MMU
Nicolas Pitre13c3f502016-07-24 11:30:15 -0400634 result = decompress_exec(bprm, sizeof(struct flat_hdr),
635 (((char *)textpos) + sizeof(struct flat_hdr)),
Al Viro3dc20cb2013-04-13 20:31:37 -0400636 (text_len + full_data
Nicolas Pitre13c3f502016-07-24 11:30:15 -0400637 - sizeof(struct flat_hdr)),
Linus Torvalds1da177e2005-04-16 15:20:36 -0700638 0);
639 memmove((void *) datapos, (void *) realdatastart,
Al Viro3dc20cb2013-04-13 20:31:37 -0400640 full_data);
Nicolas Pitre472f95f2016-07-24 11:30:26 -0400641#else
642 /*
643 * This is used on MMU systems mainly for testing.
644 * Let's use a kernel buffer to simplify things.
645 */
646 long unz_text_len = text_len - sizeof(struct flat_hdr);
647 long unz_len = unz_text_len + full_data;
648 char *unz_data = vmalloc(unz_len);
649 if (!unz_data) {
650 result = -ENOMEM;
651 } else {
652 result = decompress_exec(bprm, sizeof(struct flat_hdr),
653 unz_data, unz_len, 0);
654 if (result == 0 &&
655 (copy_to_user((void __user *)textpos + sizeof(struct flat_hdr),
656 unz_data, unz_text_len) ||
657 copy_to_user((void __user *)datapos,
658 unz_data + unz_text_len, full_data)))
659 result = -EFAULT;
660 vfree(unz_data);
661 }
662#endif
Linus Torvalds1da177e2005-04-16 15:20:36 -0700663 } else if (flags & FLAT_FLAG_GZDATA) {
Al Viro3dc20cb2013-04-13 20:31:37 -0400664 result = read_code(bprm->file, textpos, 0, text_len);
Nicolas Pitre472f95f2016-07-24 11:30:26 -0400665 if (!IS_ERR_VALUE(result)) {
666#ifndef CONFIG_MMU
Linus Torvalds1da177e2005-04-16 15:20:36 -0700667 result = decompress_exec(bprm, text_len, (char *) datapos,
Al Viro3dc20cb2013-04-13 20:31:37 -0400668 full_data, 0);
Nicolas Pitre472f95f2016-07-24 11:30:26 -0400669#else
670 char *unz_data = vmalloc(full_data);
671 if (!unz_data) {
672 result = -ENOMEM;
673 } else {
674 result = decompress_exec(bprm, text_len,
675 unz_data, full_data, 0);
676 if (result == 0 &&
677 copy_to_user((void __user *)datapos,
678 unz_data, full_data))
679 result = -EFAULT;
680 vfree(unz_data);
681 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700682#endif
Nicolas Pitre472f95f2016-07-24 11:30:26 -0400683 }
684 } else
685#endif /* CONFIG_BINFMT_ZFLAT */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700686 {
Al Viro3dc20cb2013-04-13 20:31:37 -0400687 result = read_code(bprm->file, textpos, 0, text_len);
688 if (!IS_ERR_VALUE(result))
689 result = read_code(bprm->file, datapos,
690 ntohl(hdr->data_start),
691 full_data);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700692 }
Mike Frysinger0b8c78f2009-09-23 15:57:07 -0700693 if (IS_ERR_VALUE(result)) {
Nicolas Pitre13c3f502016-07-24 11:30:15 -0400694 ret = result;
Nicolas Pitre4adbb6a2016-07-24 11:30:16 -0400695 pr_err("Unable to read code+data+bss, errno %d\n", ret);
Al Viro7696e0c32012-05-30 01:56:23 -0400696 vm_munmap(textpos, text_len + data_len + extra +
Linus Torvalds1da177e2005-04-16 15:20:36 -0700697 MAX_SHARED_LIBS * sizeof(unsigned long));
Andrew Mortondf889122006-05-20 15:00:01 -0700698 goto err;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700699 }
700 }
701
Nicolas Pitre13c3f502016-07-24 11:30:15 -0400702 start_code = textpos + sizeof(struct flat_hdr);
703 end_code = textpos + text_len;
704 text_len -= sizeof(struct flat_hdr); /* the real code len */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700705
706 /* The main program needs a little extra setup in the task structure */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700707 if (id == 0) {
708 current->mm->start_code = start_code;
709 current->mm->end_code = end_code;
710 current->mm->start_data = datapos;
711 current->mm->end_data = datapos + data_len;
712 /*
713 * set up the brk stuff, uses any slack left in data/bss/stack
714 * allocation. We put the brk after the bss (between the bss
715 * and stack) like other platforms.
David Howells0f3e4422009-01-08 12:04:47 +0000716 * Userspace code relies on the stack pointer starting out at
717 * an address right at the end of a page.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700718 */
719 current->mm->start_brk = datapos + data_len + bss_len;
720 current->mm->brk = (current->mm->start_brk + 3) & ~3;
Nicolas Pitre015feac2016-07-24 11:30:25 -0400721#ifndef CONFIG_MMU
David Howells0f3e4422009-01-08 12:04:47 +0000722 current->mm->context.end_brk = memp + memp_size - stack_len;
Nicolas Pitre015feac2016-07-24 11:30:25 -0400723#endif
Linus Torvalds1da177e2005-04-16 15:20:36 -0700724 }
725
Nicolas Pitre13c3f502016-07-24 11:30:15 -0400726 if (flags & FLAT_FLAG_KTRACE) {
Nicolas Pitre4adbb6a2016-07-24 11:30:16 -0400727 pr_info("Mapping is %lx, Entry point is %x, data_start is %x\n",
728 textpos, 0x00ffffff&ntohl(hdr->entry), ntohl(hdr->data_start));
729 pr_info("%s %s: TEXT=%lx-%lx DATA=%lx-%lx BSS=%lx-%lx\n",
730 id ? "Lib" : "Load", bprm->filename,
731 start_code, end_code, datapos, datapos + data_len,
732 datapos + data_len, (datapos + data_len + bss_len + 3) & ~3);
Nicolas Pitre13c3f502016-07-24 11:30:15 -0400733 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700734
735 /* Store the current module values into the global library structure */
736 libinfo->lib_list[id].start_code = start_code;
737 libinfo->lib_list[id].start_data = datapos;
738 libinfo->lib_list[id].start_brk = datapos + data_len + bss_len;
739 libinfo->lib_list[id].text_len = text_len;
740 libinfo->lib_list[id].loaded = 1;
741 libinfo->lib_list[id].entry = (0x00ffffff & ntohl(hdr->entry)) + textpos;
742 libinfo->lib_list[id].build_date = ntohl(hdr->build_date);
Nicolas Pitre13c3f502016-07-24 11:30:15 -0400743
Linus Torvalds1da177e2005-04-16 15:20:36 -0700744 /*
745 * We just load the allocations into some temporary memory to
746 * help simplify all this mumbo jumbo
747 *
748 * We've got two different sections of relocation entries.
Lucas De Marchi25985ed2011-03-30 22:57:33 -0300749 * The first is the GOT which resides at the beginning of the data segment
Linus Torvalds1da177e2005-04-16 15:20:36 -0700750 * and is terminated with a -1. This one can be relocated in place.
751 * The second is the extra relocation entries tacked after the image's
752 * data segment. These require a little more processing as the entry is
753 * really an offset into the image which contains an offset into the
754 * image.
755 */
756 if (flags & FLAT_FLAG_GOTPIC) {
Nicolas Pitre6e572ff2016-07-24 11:30:21 -0400757 for (rp = (unsigned long __user *)datapos; ; rp++) {
758 unsigned long addr, rp_val;
759 if (get_user(rp_val, rp))
760 return -EFAULT;
761 if (rp_val == 0xffffffff)
762 break;
763 if (rp_val) {
764 addr = calc_reloc(rp_val, libinfo, id, 0);
Luke Yang1ad3dcc2006-03-25 03:08:24 -0800765 if (addr == RELOC_FAILED) {
766 ret = -ENOEXEC;
Andrew Mortondf889122006-05-20 15:00:01 -0700767 goto err;
Luke Yang1ad3dcc2006-03-25 03:08:24 -0800768 }
Nicolas Pitre6e572ff2016-07-24 11:30:21 -0400769 if (put_user(addr, rp))
770 return -EFAULT;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700771 }
772 }
773 }
774
775 /*
776 * Now run through the relocation entries.
777 * We've got to be careful here as C++ produces relocatable zero
778 * entries in the constructor and destructor tables which are then
779 * tested for being not zero (which will always occur unless we're
780 * based from address zero). This causes an endless loop as __start
781 * is at zero. The solution used is to not relocate zero addresses.
782 * This has the negative side effect of not allowing a global data
783 * reference to be statically initialised to _stext (I've moved
784 * __start to address 4 so that is okay).
785 */
786 if (rev > OLD_FLAT_VERSION) {
Nicolas Pitre6e572ff2016-07-24 11:30:21 -0400787 unsigned long __maybe_unused persistent = 0;
Nicolas Pitre13c3f502016-07-24 11:30:15 -0400788 for (i = 0; i < relocs; i++) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700789 unsigned long addr, relval;
790
Nicolas Pitre13c3f502016-07-24 11:30:15 -0400791 /*
792 * Get the address of the pointer to be
793 * relocated (of course, the address has to be
794 * relocated first).
795 */
Nicolas Pitre6e572ff2016-07-24 11:30:21 -0400796 if (get_user(relval, reloc + i))
797 return -EFAULT;
798 relval = ntohl(relval);
Nicolas Pitre13c3f502016-07-24 11:30:15 -0400799 if (flat_set_persistent(relval, &persistent))
Bernd Schmidtf9720202007-10-03 23:41:43 +0800800 continue;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700801 addr = flat_get_relocate_addr(relval);
Nicolas Pitre6e572ff2016-07-24 11:30:21 -0400802 rp = (unsigned long __user *)calc_reloc(addr, libinfo, id, 1);
803 if (rp == (unsigned long __user *)RELOC_FAILED) {
Luke Yang1ad3dcc2006-03-25 03:08:24 -0800804 ret = -ENOEXEC;
Andrew Mortondf889122006-05-20 15:00:01 -0700805 goto err;
Luke Yang1ad3dcc2006-03-25 03:08:24 -0800806 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700807
808 /* Get the pointer's value. */
Andrew Morton576bb9c2007-10-03 23:43:57 +0800809 addr = flat_get_addr_from_rp(rp, relval, flags,
810 &persistent);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700811 if (addr != 0) {
812 /*
813 * Do the relocation. PIC relocs in the data section are
814 * already in target order
815 */
816 if ((flags & FLAT_FLAG_GOTPIC) == 0)
817 addr = ntohl(addr);
818 addr = calc_reloc(addr, libinfo, id, 0);
Luke Yang1ad3dcc2006-03-25 03:08:24 -0800819 if (addr == RELOC_FAILED) {
820 ret = -ENOEXEC;
Andrew Mortondf889122006-05-20 15:00:01 -0700821 goto err;
Luke Yang1ad3dcc2006-03-25 03:08:24 -0800822 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700823
824 /* Write back the relocated pointer. */
825 flat_put_addr_at_rp(rp, addr, relval);
826 }
827 }
828 } else {
Nicolas Pitre1b2ce442016-07-24 11:30:22 -0400829 for (i = 0; i < relocs; i++) {
830 unsigned long relval;
831 if (get_user(relval, reloc + i))
832 return -EFAULT;
833 relval = ntohl(relval);
834 old_reloc(relval);
835 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700836 }
Nicolas Pitre13c3f502016-07-24 11:30:15 -0400837
Linus Torvalds1da177e2005-04-16 15:20:36 -0700838 flush_icache_range(start_code, end_code);
839
840 /* zero the BSS, BRK and stack areas */
Nicolas Pitre467aa142016-07-24 11:30:23 -0400841 if (clear_user((void __user *)(datapos + data_len), bss_len +
842 (memp + memp_size - stack_len - /* end brk */
843 libinfo->lib_list[id].start_brk) + /* start brk */
844 stack_len))
845 return -EFAULT;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700846
847 return 0;
Luke Yang1ad3dcc2006-03-25 03:08:24 -0800848err:
849 return ret;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700850}
851
852
853/****************************************************************************/
854#ifdef CONFIG_BINFMT_SHARED_FLAT
855
856/*
857 * Load a shared library into memory. The library gets its own data
858 * segment (including bss) but not argv/argc/environ.
859 */
860
861static int load_flat_shared_library(int id, struct lib_info *libs)
862{
863 struct linux_binprm bprm;
864 int res;
865 char buf[16];
866
David Howells3a852d32011-04-28 16:26:38 +0100867 memset(&bprm, 0, sizeof(bprm));
868
Linus Torvalds1da177e2005-04-16 15:20:36 -0700869 /* Create the file name */
870 sprintf(buf, "/lib/lib%d.so", id);
871
872 /* Open the file up */
873 bprm.filename = buf;
874 bprm.file = open_exec(bprm.filename);
875 res = PTR_ERR(bprm.file);
876 if (IS_ERR(bprm.file))
877 return res;
878
Linus Torvalds34406252009-08-06 15:09:34 -0700879 bprm.cred = prepare_exec_creds();
880 res = -ENOMEM;
881 if (!bprm.cred)
882 goto out;
883
David Howells3a852d32011-04-28 16:26:38 +0100884 /* We don't really care about recalculating credentials at this point
885 * as we're past the point of no return and are dealing with shared
886 * libraries.
887 */
888 bprm.cred_prepared = 1;
889
Linus Torvalds1da177e2005-04-16 15:20:36 -0700890 res = prepare_binprm(&bprm);
891
Arnd Bergmann287980e2016-05-27 23:23:25 +0200892 if (!res)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700893 res = load_flat_file(&bprm, libs, id, NULL);
Linus Torvalds34406252009-08-06 15:09:34 -0700894
895 abort_creds(bprm.cred);
896
897out:
898 allow_write_access(bprm.file);
899 fput(bprm.file);
900
Nicolas Pitre13c3f502016-07-24 11:30:15 -0400901 return res;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700902}
903
904#endif /* CONFIG_BINFMT_SHARED_FLAT */
905/****************************************************************************/
906
907/*
908 * These are the functions used to load flat style executables and shared
909 * libraries. There is no binary dependent code anywhere else.
910 */
911
Nicolas Pitre13c3f502016-07-24 11:30:15 -0400912static int load_flat_binary(struct linux_binprm *bprm)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700913{
914 struct lib_info libinfo;
Al Viro71613c32012-10-20 22:00:48 -0400915 struct pt_regs *regs = current_pt_regs();
Nicolas Pitre015feac2016-07-24 11:30:25 -0400916 unsigned long stack_len = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700917 unsigned long start_addr;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700918 int res;
919 int i, j;
920
921 memset(&libinfo, 0, sizeof(libinfo));
Nicolas Pitre13c3f502016-07-24 11:30:15 -0400922
Linus Torvalds1da177e2005-04-16 15:20:36 -0700923 /*
924 * We have to add the size of our arguments to our stack size
925 * otherwise it's too easy for users to create stack overflows
926 * by passing in a huge argument list. And yes, we have to be
927 * pedantic and include space for the argv/envp array as it may have
928 * a lot of entries.
929 */
Nicolas Pitre015feac2016-07-24 11:30:25 -0400930#ifndef CONFIG_MMU
931 stack_len += PAGE_SIZE * MAX_ARG_PAGES - bprm->p; /* the strings */
932#endif
Nicolas Pitrea97d1572016-07-24 11:30:20 -0400933 stack_len += (bprm->argc + 1) * sizeof(char *); /* the argv array */
934 stack_len += (bprm->envc + 1) * sizeof(char *); /* the envp array */
935 stack_len = ALIGN(stack_len, FLAT_STACK_ALIGN);
Nicolas Pitre13c3f502016-07-24 11:30:15 -0400936
Linus Torvalds1da177e2005-04-16 15:20:36 -0700937 res = load_flat_file(bprm, &libinfo, 0, &stack_len);
Arnd Bergmann287980e2016-05-27 23:23:25 +0200938 if (res < 0)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700939 return res;
Nicolas Pitre13c3f502016-07-24 11:30:15 -0400940
Linus Torvalds1da177e2005-04-16 15:20:36 -0700941 /* Update data segment pointers for all libraries */
Nicolas Pitreaf521f92016-07-24 11:30:24 -0400942 for (i = 0; i < MAX_SHARED_LIBS; i++) {
943 if (!libinfo.lib_list[i].loaded)
944 continue;
945 for (j = 0; j < MAX_SHARED_LIBS; j++) {
946 unsigned long val = libinfo.lib_list[j].loaded ?
947 libinfo.lib_list[j].start_data : UNLOADED_LIB;
948 unsigned long __user *p = (unsigned long __user *)
949 libinfo.lib_list[i].start_data;
950 p -= j + 1;
951 if (put_user(val, p))
952 return -EFAULT;
953 }
954 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700955
David Howellsa6f76f22008-11-14 10:39:24 +1100956 install_exec_creds(bprm);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700957
958 set_binfmt(&flat_format);
959
Nicolas Pitre015feac2016-07-24 11:30:25 -0400960#ifdef CONFIG_MMU
961 res = setup_arg_pages(bprm, STACK_TOP, EXSTACK_DEFAULT);
962 if (!res)
963 res = create_flat_tables(bprm, bprm->p);
964#else
Nicolas Pitrea97d1572016-07-24 11:30:20 -0400965 /* Stash our initial stack pointer into the mm structure */
966 current->mm->start_stack =
967 ((current->mm->context.end_brk + stack_len + 3) & ~3) - 4;
968 pr_debug("sp=%lx\n", current->mm->start_stack);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700969
Nicolas Pitre687fd772016-07-24 11:30:19 -0400970 /* copy the arg pages onto the stack */
Nicolas Pitrea97d1572016-07-24 11:30:20 -0400971 res = transfer_args_to_stack(bprm, &current->mm->start_stack);
972 if (!res)
973 res = create_flat_tables(bprm, current->mm->start_stack);
Nicolas Pitre015feac2016-07-24 11:30:25 -0400974#endif
Nicolas Pitre687fd772016-07-24 11:30:19 -0400975 if (res)
976 return res;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700977
Linus Torvalds1da177e2005-04-16 15:20:36 -0700978 /* Fake some return addresses to ensure the call chain will
979 * initialise library in order for us. We are required to call
980 * lib 1 first, then 2, ... and finally the main program (id 0).
981 */
982 start_addr = libinfo.lib_list[0].entry;
983
984#ifdef CONFIG_BINFMT_SHARED_FLAT
Nicolas Pitre13c3f502016-07-24 11:30:15 -0400985 for (i = MAX_SHARED_LIBS-1; i > 0; i--) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700986 if (libinfo.lib_list[i].loaded) {
987 /* Push previos first to call address */
Nicolas Pitrea97d1572016-07-24 11:30:20 -0400988 unsigned long __user *sp;
989 current->mm->start_stack -= sizeof(unsigned long);
990 sp = (unsigned long __user *)current->mm->start_stack;
991 __put_user(start_addr, sp);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700992 start_addr = libinfo.lib_list[i].entry;
993 }
994 }
995#endif
Nicolas Pitre13c3f502016-07-24 11:30:15 -0400996
Takashi YOSHII74c27c42008-08-11 20:10:54 +0900997#ifdef FLAT_PLAT_INIT
998 FLAT_PLAT_INIT(regs);
999#endif
Nicolas Pitre13c3f502016-07-24 11:30:15 -04001000
Nicolas Pitre4adbb6a2016-07-24 11:30:16 -04001001 pr_debug("start_thread(regs=0x%p, entry=0x%lx, start_stack=0x%lx)\n",
1002 regs, start_addr, current->mm->start_stack);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001003 start_thread(regs, start_addr, current->mm->start_stack);
1004
Linus Torvalds1da177e2005-04-16 15:20:36 -07001005 return 0;
1006}
1007
1008/****************************************************************************/
1009
1010static int __init init_flat_binfmt(void)
1011{
Al Viro8fc3dc52012-03-17 03:05:16 -04001012 register_binfmt(&flat_format);
1013 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001014}
Linus Torvalds1da177e2005-04-16 15:20:36 -07001015core_initcall(init_flat_binfmt);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001016
1017/****************************************************************************/