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Greg Kroah-Hartmanb2441312017-11-01 15:07:57 +01001// SPDX-License-Identifier: GPL-2.0
Linus Torvalds1da177e2005-04-16 15:20:36 -07002/****************************************************************************/
3/*
4 * linux/fs/binfmt_flat.c
5 *
6 * Copyright (C) 2000-2003 David McCullough <davidm@snapgear.com>
7 * Copyright (C) 2002 Greg Ungerer <gerg@snapgear.com>
8 * Copyright (C) 2002 SnapGear, by Paul Dale <pauli@snapgear.com>
9 * Copyright (C) 2000, 2001 Lineo, by David McCullough <davidm@lineo.com>
10 * based heavily on:
11 *
12 * linux/fs/binfmt_aout.c:
13 * Copyright (C) 1991, 1992, 1996 Linus Torvalds
14 * linux/fs/binfmt_flat.c for 2.0 kernel
15 * Copyright (C) 1998 Kenneth Albanowski <kjahds@kjahds.com>
16 * JAN/99 -- coded full program relocation (gerg@snapgear.com)
17 */
18
Nicolas Pitre4adbb6a2016-07-24 11:30:16 -040019#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
20
Linus Torvalds1da177e2005-04-16 15:20:36 -070021#include <linux/kernel.h>
22#include <linux/sched.h>
Ingo Molnar68db0cf2017-02-08 18:51:37 +010023#include <linux/sched/task_stack.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070024#include <linux/mm.h>
25#include <linux/mman.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070026#include <linux/errno.h>
27#include <linux/signal.h>
28#include <linux/string.h>
29#include <linux/fs.h>
30#include <linux/file.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070031#include <linux/ptrace.h>
32#include <linux/user.h>
33#include <linux/slab.h>
34#include <linux/binfmts.h>
35#include <linux/personality.h>
36#include <linux/init.h>
37#include <linux/flat.h>
Nicolas Pitre13c3f502016-07-24 11:30:15 -040038#include <linux/uaccess.h>
Nicolas Pitre472f95f2016-07-24 11:30:26 -040039#include <linux/vmalloc.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070040
41#include <asm/byteorder.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070042#include <asm/unaligned.h>
43#include <asm/cacheflush.h>
Oskar Schirmerc3dc5be2009-05-28 14:34:31 -070044#include <asm/page.h>
Christoph Hellwig06d2bfe2019-06-13 09:08:52 +020045#include <asm/flat.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070046
Christoph Hellwig02da2832019-06-13 09:08:49 +020047#ifndef flat_get_relocate_addr
48#define flat_get_relocate_addr(rel) (rel)
49#endif
Linus Torvalds1da177e2005-04-16 15:20:36 -070050
51/****************************************************************************/
52
Oskar Schirmerc3dc5be2009-05-28 14:34:31 -070053/*
Mike Frysinger2e94de82010-06-04 14:14:53 -070054 * User data (data section and bss) needs to be aligned.
55 * We pick 0x20 here because it is the max value elf2flt has always
56 * used in producing FLAT files, and because it seems to be large
57 * enough to make all the gcc alignment related tests happy.
58 */
59#define FLAT_DATA_ALIGN (0x20)
60
61/*
62 * User data (stack) also needs to be aligned.
63 * Here we can be a bit looser than the data sections since this
64 * needs to only meet arch ABI requirements.
Oskar Schirmerc3dc5be2009-05-28 14:34:31 -070065 */
Mike Frysinger29520952010-06-29 15:05:21 -070066#define FLAT_STACK_ALIGN max_t(unsigned long, sizeof(void *), ARCH_SLAB_MINALIGN)
Oskar Schirmerc3dc5be2009-05-28 14:34:31 -070067
Linus Torvalds1da177e2005-04-16 15:20:36 -070068#define RELOC_FAILED 0xff00ff01 /* Relocation incorrect somewhere */
69#define UNLOADED_LIB 0x7ff000ff /* Placeholder for unused library */
70
Christoph Hellwiga445d982019-06-13 09:09:01 +020071#ifdef CONFIG_BINFMT_SHARED_FLAT
72#define MAX_SHARED_LIBS (4)
73#else
74#define MAX_SHARED_LIBS (1)
75#endif
76
Linus Torvalds1da177e2005-04-16 15:20:36 -070077struct lib_info {
78 struct {
79 unsigned long start_code; /* Start of text segment */
80 unsigned long start_data; /* Start of data segment */
81 unsigned long start_brk; /* End of data segment */
82 unsigned long text_len; /* Length of text segment */
83 unsigned long entry; /* Start address for this module */
84 unsigned long build_date; /* When this one was compiled */
Nicolas Pitre13c3f502016-07-24 11:30:15 -040085 bool loaded; /* Has this library been loaded? */
Linus Torvalds1da177e2005-04-16 15:20:36 -070086 } lib_list[MAX_SHARED_LIBS];
87};
88
89#ifdef CONFIG_BINFMT_SHARED_FLAT
90static int load_flat_shared_library(int id, struct lib_info *p);
91#endif
92
Al Viro71613c32012-10-20 22:00:48 -040093static int load_flat_binary(struct linux_binprm *);
Masami Hiramatsuf6151df2009-12-17 15:27:16 -080094static int flat_core_dump(struct coredump_params *cprm);
Linus Torvalds1da177e2005-04-16 15:20:36 -070095
Linus Torvalds1da177e2005-04-16 15:20:36 -070096static struct linux_binfmt flat_format = {
97 .module = THIS_MODULE,
98 .load_binary = load_flat_binary,
99 .core_dump = flat_core_dump,
100 .min_coredump = PAGE_SIZE
101};
102
103/****************************************************************************/
104/*
105 * Routine writes a core dump image in the current directory.
106 * Currently only a stub-function.
107 */
108
Masami Hiramatsuf6151df2009-12-17 15:27:16 -0800109static int flat_core_dump(struct coredump_params *cprm)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700110{
Nicolas Pitre4adbb6a2016-07-24 11:30:16 -0400111 pr_warn("Process %s:%d received signr %d and should have core dumped\n",
112 current->comm, current->pid, cprm->siginfo->si_signo);
Nicolas Pitre13c3f502016-07-24 11:30:15 -0400113 return 1;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700114}
115
116/****************************************************************************/
117/*
118 * create_flat_tables() parses the env- and arg-strings in new user
119 * memory and creates the pointer tables from them, and puts their
Nicolas Pitrea97d1572016-07-24 11:30:20 -0400120 * addresses on the "stack", recording the new stack pointer value.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700121 */
122
Nicolas Pitrea97d1572016-07-24 11:30:20 -0400123static int create_flat_tables(struct linux_binprm *bprm, unsigned long arg_start)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700124{
Nicolas Pitrea97d1572016-07-24 11:30:20 -0400125 char __user *p;
126 unsigned long __user *sp;
127 long i, len;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700128
Nicolas Pitrea97d1572016-07-24 11:30:20 -0400129 p = (char __user *)arg_start;
130 sp = (unsigned long __user *)current->mm->start_stack;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700131
Nicolas Pitrea97d1572016-07-24 11:30:20 -0400132 sp -= bprm->envc + 1;
133 sp -= bprm->argc + 1;
Christoph Hellwigbdd15a22019-06-13 09:08:51 +0200134 if (IS_ENABLED(CONFIG_BINFMT_FLAT_ARGVP_ENVP_ON_STACK))
135 sp -= 2; /* argvp + envp */
Nicolas Pitrea97d1572016-07-24 11:30:20 -0400136 sp -= 1; /* &argc */
137
138 current->mm->start_stack = (unsigned long)sp & -FLAT_STACK_ALIGN;
139 sp = (unsigned long __user *)current->mm->start_stack;
140
Al Viro8861fd572020-02-19 09:32:55 -0500141 if (put_user(bprm->argc, sp++))
142 return -EFAULT;
Christoph Hellwigbdd15a22019-06-13 09:08:51 +0200143 if (IS_ENABLED(CONFIG_BINFMT_FLAT_ARGVP_ENVP_ON_STACK)) {
Nicolas Pitrea97d1572016-07-24 11:30:20 -0400144 unsigned long argv, envp;
145 argv = (unsigned long)(sp + 2);
146 envp = (unsigned long)(sp + 2 + bprm->argc + 1);
Al Viro8861fd572020-02-19 09:32:55 -0500147 if (put_user(argv, sp++) || put_user(envp, sp++))
148 return -EFAULT;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700149 }
150
Nicolas Pitrea97d1572016-07-24 11:30:20 -0400151 current->mm->arg_start = (unsigned long)p;
152 for (i = bprm->argc; i > 0; i--) {
Al Viro8861fd572020-02-19 09:32:55 -0500153 if (put_user((unsigned long)p, sp++))
154 return -EFAULT;
Nicolas Pitrea97d1572016-07-24 11:30:20 -0400155 len = strnlen_user(p, MAX_ARG_STRLEN);
156 if (!len || len > MAX_ARG_STRLEN)
157 return -EINVAL;
158 p += len;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700159 }
Al Viro8861fd572020-02-19 09:32:55 -0500160 if (put_user(0, sp++))
161 return -EFAULT;
Nicolas Pitrea97d1572016-07-24 11:30:20 -0400162 current->mm->arg_end = (unsigned long)p;
163
164 current->mm->env_start = (unsigned long) p;
165 for (i = bprm->envc; i > 0; i--) {
Al Viro8861fd572020-02-19 09:32:55 -0500166 if (put_user((unsigned long)p, sp++))
167 return -EFAULT;
Nicolas Pitrea97d1572016-07-24 11:30:20 -0400168 len = strnlen_user(p, MAX_ARG_STRLEN);
169 if (!len || len > MAX_ARG_STRLEN)
170 return -EINVAL;
171 p += len;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700172 }
Al Viro8861fd572020-02-19 09:32:55 -0500173 if (put_user(0, sp++))
174 return -EFAULT;
Nicolas Pitrea97d1572016-07-24 11:30:20 -0400175 current->mm->env_end = (unsigned long)p;
176
177 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700178}
179
180/****************************************************************************/
181
182#ifdef CONFIG_BINFMT_ZFLAT
183
184#include <linux/zlib.h>
185
186#define LBUFSIZE 4000
187
188/* gzip flag byte */
189#define ASCII_FLAG 0x01 /* bit 0 set: file probably ASCII text */
190#define CONTINUATION 0x02 /* bit 1 set: continuation of multi-part gzip file */
191#define EXTRA_FIELD 0x04 /* bit 2 set: extra field present */
192#define ORIG_NAME 0x08 /* bit 3 set: original file name present */
193#define COMMENT 0x10 /* bit 4 set: file comment present */
194#define ENCRYPTED 0x20 /* bit 5 set: file is encrypted */
195#define RESERVED 0xC0 /* bit 6,7: reserved */
196
Christoph Hellwigbdd1d2d2017-09-01 17:39:13 +0200197static int decompress_exec(struct linux_binprm *bprm, loff_t fpos, char *dst,
198 long len, int fd)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700199{
200 unsigned char *buf;
201 z_stream strm;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700202 int ret, retval;
203
Christoph Hellwigbdd1d2d2017-09-01 17:39:13 +0200204 pr_debug("decompress_exec(offset=%llx,buf=%p,len=%lx)\n", fpos, dst, len);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700205
206 memset(&strm, 0, sizeof(strm));
207 strm.workspace = kmalloc(zlib_inflate_workspacesize(), GFP_KERNEL);
Markus Elfring9367bb72017-09-08 16:16:14 -0700208 if (!strm.workspace)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700209 return -ENOMEM;
Markus Elfring9367bb72017-09-08 16:16:14 -0700210
Linus Torvalds1da177e2005-04-16 15:20:36 -0700211 buf = kmalloc(LBUFSIZE, GFP_KERNEL);
Markus Elfring9367bb72017-09-08 16:16:14 -0700212 if (!buf) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700213 retval = -ENOMEM;
214 goto out_free;
215 }
216
217 /* Read in first chunk of data and parse gzip header. */
Christoph Hellwigbdd1d2d2017-09-01 17:39:13 +0200218 ret = kernel_read(bprm->file, buf, LBUFSIZE, &fpos);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700219
220 strm.next_in = buf;
221 strm.avail_in = ret;
222 strm.total_in = 0;
223
224 retval = -ENOEXEC;
225
226 /* Check minimum size -- gzip header */
227 if (ret < 10) {
Nicolas Pitre4adbb6a2016-07-24 11:30:16 -0400228 pr_debug("file too small?\n");
Linus Torvalds1da177e2005-04-16 15:20:36 -0700229 goto out_free_buf;
230 }
231
232 /* Check gzip magic number */
233 if ((buf[0] != 037) || ((buf[1] != 0213) && (buf[1] != 0236))) {
Nicolas Pitre4adbb6a2016-07-24 11:30:16 -0400234 pr_debug("unknown compression magic?\n");
Linus Torvalds1da177e2005-04-16 15:20:36 -0700235 goto out_free_buf;
236 }
237
238 /* Check gzip method */
239 if (buf[2] != 8) {
Nicolas Pitre4adbb6a2016-07-24 11:30:16 -0400240 pr_debug("unknown compression method?\n");
Linus Torvalds1da177e2005-04-16 15:20:36 -0700241 goto out_free_buf;
242 }
243 /* Check gzip flags */
244 if ((buf[3] & ENCRYPTED) || (buf[3] & CONTINUATION) ||
245 (buf[3] & RESERVED)) {
Nicolas Pitre4adbb6a2016-07-24 11:30:16 -0400246 pr_debug("unknown flags?\n");
Linus Torvalds1da177e2005-04-16 15:20:36 -0700247 goto out_free_buf;
248 }
249
250 ret = 10;
251 if (buf[3] & EXTRA_FIELD) {
252 ret += 2 + buf[10] + (buf[11] << 8);
Nicolas Pitre13c3f502016-07-24 11:30:15 -0400253 if (unlikely(ret >= LBUFSIZE)) {
Nicolas Pitre4adbb6a2016-07-24 11:30:16 -0400254 pr_debug("buffer overflow (EXTRA)?\n");
Linus Torvalds1da177e2005-04-16 15:20:36 -0700255 goto out_free_buf;
256 }
257 }
258 if (buf[3] & ORIG_NAME) {
Volodymyr G. Lukiianykf4cfb182008-10-15 22:01:15 -0700259 while (ret < LBUFSIZE && buf[ret++] != 0)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700260 ;
Nicolas Pitre13c3f502016-07-24 11:30:15 -0400261 if (unlikely(ret == LBUFSIZE)) {
Nicolas Pitre4adbb6a2016-07-24 11:30:16 -0400262 pr_debug("buffer overflow (ORIG_NAME)?\n");
Linus Torvalds1da177e2005-04-16 15:20:36 -0700263 goto out_free_buf;
264 }
265 }
266 if (buf[3] & COMMENT) {
Volodymyr G. Lukiianykf4cfb182008-10-15 22:01:15 -0700267 while (ret < LBUFSIZE && buf[ret++] != 0)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700268 ;
Nicolas Pitre13c3f502016-07-24 11:30:15 -0400269 if (unlikely(ret == LBUFSIZE)) {
Nicolas Pitre4adbb6a2016-07-24 11:30:16 -0400270 pr_debug("buffer overflow (COMMENT)?\n");
Linus Torvalds1da177e2005-04-16 15:20:36 -0700271 goto out_free_buf;
272 }
273 }
274
275 strm.next_in += ret;
276 strm.avail_in -= ret;
277
278 strm.next_out = dst;
279 strm.avail_out = len;
280 strm.total_out = 0;
281
282 if (zlib_inflateInit2(&strm, -MAX_WBITS) != Z_OK) {
Nicolas Pitre4adbb6a2016-07-24 11:30:16 -0400283 pr_debug("zlib init failed?\n");
Linus Torvalds1da177e2005-04-16 15:20:36 -0700284 goto out_free_buf;
285 }
286
287 while ((ret = zlib_inflate(&strm, Z_NO_FLUSH)) == Z_OK) {
Christoph Hellwigbdd1d2d2017-09-01 17:39:13 +0200288 ret = kernel_read(bprm->file, buf, LBUFSIZE, &fpos);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700289 if (ret <= 0)
290 break;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700291 len -= ret;
292
293 strm.next_in = buf;
294 strm.avail_in = ret;
295 strm.total_in = 0;
296 }
297
298 if (ret < 0) {
Nicolas Pitre4adbb6a2016-07-24 11:30:16 -0400299 pr_debug("decompression failed (%d), %s\n",
Linus Torvalds1da177e2005-04-16 15:20:36 -0700300 ret, strm.msg);
301 goto out_zlib;
302 }
303
304 retval = 0;
305out_zlib:
306 zlib_inflateEnd(&strm);
307out_free_buf:
308 kfree(buf);
309out_free:
310 kfree(strm.workspace);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700311 return retval;
312}
313
314#endif /* CONFIG_BINFMT_ZFLAT */
315
316/****************************************************************************/
317
318static unsigned long
319calc_reloc(unsigned long r, struct lib_info *p, int curid, int internalp)
320{
321 unsigned long addr;
322 int id;
323 unsigned long start_brk;
324 unsigned long start_data;
325 unsigned long text_len;
326 unsigned long start_code;
327
328#ifdef CONFIG_BINFMT_SHARED_FLAT
329 if (r == 0)
330 id = curid; /* Relocs of 0 are always self referring */
331 else {
332 id = (r >> 24) & 0xff; /* Find ID for this reloc */
333 r &= 0x00ffffff; /* Trim ID off here */
334 }
335 if (id >= MAX_SHARED_LIBS) {
Nicolas Pitre4adbb6a2016-07-24 11:30:16 -0400336 pr_err("reference 0x%lx to shared library %d", r, id);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700337 goto failed;
338 }
339 if (curid != id) {
340 if (internalp) {
Nicolas Pitre4adbb6a2016-07-24 11:30:16 -0400341 pr_err("reloc address 0x%lx not in same module "
342 "(%d != %d)", r, curid, id);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700343 goto failed;
Nicolas Pitre13c3f502016-07-24 11:30:15 -0400344 } else if (!p->lib_list[id].loaded &&
345 load_flat_shared_library(id, p) < 0) {
Nicolas Pitre4adbb6a2016-07-24 11:30:16 -0400346 pr_err("failed to load library %d", id);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700347 goto failed;
348 }
349 /* Check versioning information (i.e. time stamps) */
350 if (p->lib_list[id].build_date && p->lib_list[curid].build_date &&
351 p->lib_list[curid].build_date < p->lib_list[id].build_date) {
Nicolas Pitre4adbb6a2016-07-24 11:30:16 -0400352 pr_err("library %d is younger than %d", id, curid);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700353 goto failed;
354 }
355 }
356#else
357 id = 0;
358#endif
359
360 start_brk = p->lib_list[id].start_brk;
361 start_data = p->lib_list[id].start_data;
362 start_code = p->lib_list[id].start_code;
363 text_len = p->lib_list[id].text_len;
364
Christoph Hellwig9ee24b22019-06-13 09:08:47 +0200365 if (r > start_brk - start_data + text_len) {
Nicolas Pitre4adbb6a2016-07-24 11:30:16 -0400366 pr_err("reloc outside program 0x%lx (0 - 0x%lx/0x%lx)",
Nicolas Pitre13c3f502016-07-24 11:30:15 -0400367 r, start_brk-start_data+text_len, text_len);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700368 goto failed;
369 }
370
371 if (r < text_len) /* In text segment */
372 addr = r + start_code;
373 else /* In data segment */
374 addr = r - text_len + start_data;
375
376 /* Range checked already above so doing the range tests is redundant...*/
Nicolas Pitre13c3f502016-07-24 11:30:15 -0400377 return addr;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700378
379failed:
Nicolas Pitre4adbb6a2016-07-24 11:30:16 -0400380 pr_cont(", killing %s!\n", current->comm);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700381 send_sig(SIGSEGV, current, 0);
382
383 return RELOC_FAILED;
384}
385
386/****************************************************************************/
387
Christoph Hellwigcf9a5662019-06-13 09:08:58 +0200388#ifdef CONFIG_BINFMT_FLAT_OLD
Axel Lin34303432014-06-04 16:12:15 -0700389static void old_reloc(unsigned long rl)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700390{
Nicolas Pitre13c3f502016-07-24 11:30:15 -0400391 static const char *segment[] = { "TEXT", "DATA", "BSS", "*UNKNOWN*" };
Linus Torvalds1da177e2005-04-16 15:20:36 -0700392 flat_v2_reloc_t r;
Nicolas Pitre1b2ce442016-07-24 11:30:22 -0400393 unsigned long __user *ptr;
394 unsigned long val;
Nicolas Pitre13c3f502016-07-24 11:30:15 -0400395
Linus Torvalds1da177e2005-04-16 15:20:36 -0700396 r.value = rl;
397#if defined(CONFIG_COLDFIRE)
Nicolas Pitre1b2ce442016-07-24 11:30:22 -0400398 ptr = (unsigned long __user *)(current->mm->start_code + r.reloc.offset);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700399#else
Nicolas Pitre1b2ce442016-07-24 11:30:22 -0400400 ptr = (unsigned long __user *)(current->mm->start_data + r.reloc.offset);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700401#endif
Nicolas Pitre1b2ce442016-07-24 11:30:22 -0400402 get_user(val, ptr);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700403
Nicolas Pitre4adbb6a2016-07-24 11:30:16 -0400404 pr_debug("Relocation of variable at DATASEG+%x "
405 "(address %p, currently %lx) into segment %s\n",
Nicolas Pitre1b2ce442016-07-24 11:30:22 -0400406 r.reloc.offset, ptr, val, segment[r.reloc.type]);
Nicolas Pitre13c3f502016-07-24 11:30:15 -0400407
Linus Torvalds1da177e2005-04-16 15:20:36 -0700408 switch (r.reloc.type) {
409 case OLD_FLAT_RELOC_TYPE_TEXT:
Nicolas Pitre1b2ce442016-07-24 11:30:22 -0400410 val += current->mm->start_code;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700411 break;
412 case OLD_FLAT_RELOC_TYPE_DATA:
Nicolas Pitre1b2ce442016-07-24 11:30:22 -0400413 val += current->mm->start_data;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700414 break;
415 case OLD_FLAT_RELOC_TYPE_BSS:
Nicolas Pitre1b2ce442016-07-24 11:30:22 -0400416 val += current->mm->end_data;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700417 break;
418 default:
Nicolas Pitre4adbb6a2016-07-24 11:30:16 -0400419 pr_err("Unknown relocation type=%x\n", r.reloc.type);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700420 break;
421 }
Nicolas Pitre1b2ce442016-07-24 11:30:22 -0400422 put_user(val, ptr);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700423
Nicolas Pitre1b2ce442016-07-24 11:30:22 -0400424 pr_debug("Relocation became %lx\n", val);
Nicolas Pitre13c3f502016-07-24 11:30:15 -0400425}
Christoph Hellwigcf9a5662019-06-13 09:08:58 +0200426#endif /* CONFIG_BINFMT_FLAT_OLD */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700427
428/****************************************************************************/
429
Nicolas Pitre13c3f502016-07-24 11:30:15 -0400430static int load_flat_file(struct linux_binprm *bprm,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700431 struct lib_info *libinfo, int id, unsigned long *extra_stack)
432{
Nicolas Pitre13c3f502016-07-24 11:30:15 -0400433 struct flat_hdr *hdr;
434 unsigned long textpos, datapos, realdatastart;
Al Viro468138d2017-05-02 19:52:17 -0400435 u32 text_len, data_len, bss_len, stack_len, full_data, flags;
Nicolas Pitre13c3f502016-07-24 11:30:15 -0400436 unsigned long len, memp, memp_size, extra, rlim;
Christoph Hellwig3b977712019-06-13 09:08:56 +0200437 __be32 __user *reloc;
438 u32 __user *rp;
Nicolas Pitre13c3f502016-07-24 11:30:15 -0400439 int i, rev, relocs;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700440 loff_t fpos;
441 unsigned long start_code, end_code;
Nicolas Pitre13c3f502016-07-24 11:30:15 -0400442 ssize_t result;
Luke Yang1ad3dcc2006-03-25 03:08:24 -0800443 int ret;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700444
445 hdr = ((struct flat_hdr *) bprm->buf); /* exec-header */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700446
447 text_len = ntohl(hdr->data_start);
448 data_len = ntohl(hdr->data_end) - ntohl(hdr->data_start);
449 bss_len = ntohl(hdr->bss_end) - ntohl(hdr->data_end);
450 stack_len = ntohl(hdr->stack_size);
451 if (extra_stack) {
452 stack_len += *extra_stack;
453 *extra_stack = stack_len;
454 }
455 relocs = ntohl(hdr->reloc_count);
456 flags = ntohl(hdr->flags);
457 rev = ntohl(hdr->rev);
Al Viro3dc20cb2013-04-13 20:31:37 -0400458 full_data = data_len + relocs * sizeof(unsigned long);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700459
Greg Ungerer845884d2006-01-10 16:59:37 +1000460 if (strncmp(hdr->magic, "bFLT", 4)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700461 /*
Mike Frysingere2a366d2008-02-14 19:31:29 -0800462 * Previously, here was a printk to tell people
463 * "BINFMT_FLAT: bad header magic".
464 * But for the kernel which also use ELF FD-PIC format, this
465 * error message is confusing.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700466 * because a lot of people do not manage to produce good
Linus Torvalds1da177e2005-04-16 15:20:36 -0700467 */
Luke Yang1ad3dcc2006-03-25 03:08:24 -0800468 ret = -ENOEXEC;
469 goto err;
Greg Ungerer845884d2006-01-10 16:59:37 +1000470 }
471
472 if (flags & FLAT_FLAG_KTRACE)
Nicolas Pitre4adbb6a2016-07-24 11:30:16 -0400473 pr_info("Loading file: %s\n", bprm->filename);
Greg Ungerer845884d2006-01-10 16:59:37 +1000474
Christoph Hellwigcf9a5662019-06-13 09:08:58 +0200475#ifdef CONFIG_BINFMT_FLAT_OLD
Greg Ungerer845884d2006-01-10 16:59:37 +1000476 if (rev != FLAT_VERSION && rev != OLD_FLAT_VERSION) {
Nicolas Pitre4adbb6a2016-07-24 11:30:16 -0400477 pr_err("bad flat file version 0x%x (supported 0x%lx and 0x%lx)\n",
478 rev, FLAT_VERSION, OLD_FLAT_VERSION);
Luke Yang1ad3dcc2006-03-25 03:08:24 -0800479 ret = -ENOEXEC;
480 goto err;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700481 }
Nicolas Pitre13c3f502016-07-24 11:30:15 -0400482
Linus Torvalds1da177e2005-04-16 15:20:36 -0700483 /* Don't allow old format executables to use shared libraries */
484 if (rev == OLD_FLAT_VERSION && id != 0) {
Nicolas Pitre4adbb6a2016-07-24 11:30:16 -0400485 pr_err("shared libraries are not available before rev 0x%lx\n",
486 FLAT_VERSION);
Luke Yang1ad3dcc2006-03-25 03:08:24 -0800487 ret = -ENOEXEC;
488 goto err;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700489 }
490
491 /*
Christoph Hellwigcf9a5662019-06-13 09:08:58 +0200492 * fix up the flags for the older format, there were all kinds
493 * of endian hacks, this only works for the simple cases
494 */
495 if (rev == OLD_FLAT_VERSION &&
496 (flags || IS_ENABLED(CONFIG_BINFMT_FLAT_OLD_ALWAYS_RAM)))
497 flags = FLAT_FLAG_RAM;
498
499#else /* CONFIG_BINFMT_FLAT_OLD */
500 if (rev != FLAT_VERSION) {
501 pr_err("bad flat file version 0x%x (supported 0x%lx)\n",
502 rev, FLAT_VERSION);
503 ret = -ENOEXEC;
504 goto err;
505 }
506#endif /* !CONFIG_BINFMT_FLAT_OLD */
507
508 /*
Nicolas Pitrec995ee22016-07-24 11:30:17 -0400509 * Make sure the header params are sane.
510 * 28 bits (256 MB) is way more than reasonable in this case.
511 * If some top bits are set we have probable binary corruption.
512 */
513 if ((text_len | data_len | bss_len | stack_len | full_data) >> 28) {
514 pr_err("bad header\n");
515 ret = -ENOEXEC;
516 goto err;
517 }
518
Linus Torvalds1da177e2005-04-16 15:20:36 -0700519#ifndef CONFIG_BINFMT_ZFLAT
520 if (flags & (FLAT_FLAG_GZIP|FLAT_FLAG_GZDATA)) {
Nicolas Pitre4adbb6a2016-07-24 11:30:16 -0400521 pr_err("Support for ZFLAT executables is not enabled.\n");
Luke Yang1ad3dcc2006-03-25 03:08:24 -0800522 ret = -ENOEXEC;
523 goto err;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700524 }
525#endif
526
527 /*
528 * Check initial limits. This avoids letting people circumvent
529 * size limits imposed on them by creating programs with large
530 * arrays in the data or bss.
531 */
Jiri Slabyd554ed892010-03-05 13:42:42 -0800532 rlim = rlimit(RLIMIT_DATA);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700533 if (rlim >= RLIM_INFINITY)
534 rlim = ~0;
Luke Yang1ad3dcc2006-03-25 03:08:24 -0800535 if (data_len + bss_len > rlim) {
536 ret = -ENOMEM;
537 goto err;
538 }
539
Linus Torvalds1da177e2005-04-16 15:20:36 -0700540 /* Flush all traces of the currently running executable */
541 if (id == 0) {
Eric W. Biederman23887772020-05-03 07:54:10 -0500542 ret = begin_new_exec(bprm);
Nicolas Pitre13c3f502016-07-24 11:30:15 -0400543 if (ret)
Andrew Mortondf889122006-05-20 15:00:01 -0700544 goto err;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700545
546 /* OK, This is the point of no return */
Malcolm Parsonsfcc18e82006-06-26 11:49:41 +1000547 set_personality(PER_LINUX_32BIT);
Linus Torvalds221af7f2010-01-28 22:14:42 -0800548 setup_new_exec(bprm);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700549 }
550
551 /*
552 * calculate the extra space we need to map in
553 */
Andrew Morton0e647c02007-10-16 23:27:26 -0700554 extra = max_t(unsigned long, bss_len + stack_len,
555 relocs * sizeof(unsigned long));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700556
557 /*
558 * there are a couple of cases here, the separate code/data
559 * case, and then the fully copied to RAM case which lumps
560 * it all together.
561 */
Nicolas Pitre015feac2016-07-24 11:30:25 -0400562 if (!IS_ENABLED(CONFIG_MMU) && !(flags & (FLAT_FLAG_RAM|FLAT_FLAG_GZIP))) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700563 /*
564 * this should give us a ROM ptr, but if it doesn't we don't
565 * really care
566 */
Nicolas Pitre4adbb6a2016-07-24 11:30:16 -0400567 pr_debug("ROM mapping of file (we hope)\n");
Linus Torvalds1da177e2005-04-16 15:20:36 -0700568
Linus Torvalds6be5ceb2012-04-20 17:13:58 -0700569 textpos = vm_mmap(bprm->file, 0, text_len, PROT_READ|PROT_EXEC,
Matt Helsley925d1c42008-04-29 01:01:36 -0700570 MAP_PRIVATE|MAP_EXECUTABLE, 0);
Mike Frysinger0b8c78f2009-09-23 15:57:07 -0700571 if (!textpos || IS_ERR_VALUE(textpos)) {
Luke Yang1ad3dcc2006-03-25 03:08:24 -0800572 ret = textpos;
Nicolas Pitre13c3f502016-07-24 11:30:15 -0400573 if (!textpos)
574 ret = -ENOMEM;
Nicolas Pitre4adbb6a2016-07-24 11:30:16 -0400575 pr_err("Unable to mmap process text, errno %d\n", ret);
Andrew Mortondf889122006-05-20 15:00:01 -0700576 goto err;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700577 }
578
Christoph Hellwiga2357222019-06-13 09:09:02 +0200579 len = data_len + extra;
David Howells0f3e4422009-01-08 12:04:47 +0000580 len = PAGE_ALIGN(len);
Nicolas Pitre13c3f502016-07-24 11:30:15 -0400581 realdatastart = vm_mmap(NULL, 0, len,
Greg Ungerer72613e5f2007-02-07 12:03:08 +1000582 PROT_READ|PROT_WRITE|PROT_EXEC, MAP_PRIVATE, 0);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700583
Mike Frysinger0b8c78f2009-09-23 15:57:07 -0700584 if (realdatastart == 0 || IS_ERR_VALUE(realdatastart)) {
Luke Yang1ad3dcc2006-03-25 03:08:24 -0800585 ret = realdatastart;
Nicolas Pitre13c3f502016-07-24 11:30:15 -0400586 if (!realdatastart)
587 ret = -ENOMEM;
Nicolas Pitre4adbb6a2016-07-24 11:30:16 -0400588 pr_err("Unable to allocate RAM for process data, "
Nicolas Pitre13c3f502016-07-24 11:30:15 -0400589 "errno %d\n", ret);
590 vm_munmap(textpos, text_len);
Andrew Mortondf889122006-05-20 15:00:01 -0700591 goto err;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700592 }
Christoph Hellwiga2357222019-06-13 09:09:02 +0200593 datapos = ALIGN(realdatastart, FLAT_DATA_ALIGN);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700594
Geert Uytterhoevena8605422017-07-16 13:57:27 +0200595 pr_debug("Allocated data+bss+stack (%u bytes): %lx\n",
Nicolas Pitre4adbb6a2016-07-24 11:30:16 -0400596 data_len + bss_len + stack_len, datapos);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700597
598 fpos = ntohl(hdr->data_start);
599#ifdef CONFIG_BINFMT_ZFLAT
600 if (flags & FLAT_FLAG_GZDATA) {
Nicolas Pitre13c3f502016-07-24 11:30:15 -0400601 result = decompress_exec(bprm, fpos, (char *)datapos,
Al Viro3dc20cb2013-04-13 20:31:37 -0400602 full_data, 0);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700603 } else
604#endif
605 {
Al Viro3dc20cb2013-04-13 20:31:37 -0400606 result = read_code(bprm->file, datapos, fpos,
607 full_data);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700608 }
Mike Frysinger0b8c78f2009-09-23 15:57:07 -0700609 if (IS_ERR_VALUE(result)) {
Nicolas Pitre13c3f502016-07-24 11:30:15 -0400610 ret = result;
Nicolas Pitre4adbb6a2016-07-24 11:30:16 -0400611 pr_err("Unable to read data+bss, errno %d\n", ret);
Al Viro7696e0c32012-05-30 01:56:23 -0400612 vm_munmap(textpos, text_len);
613 vm_munmap(realdatastart, len);
Andrew Mortondf889122006-05-20 15:00:01 -0700614 goto err;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700615 }
616
Christoph Hellwig3b977712019-06-13 09:08:56 +0200617 reloc = (__be32 __user *)
Nicolas Pitre13c3f502016-07-24 11:30:15 -0400618 (datapos + (ntohl(hdr->reloc_start) - text_len));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700619 memp = realdatastart;
David Howells0f3e4422009-01-08 12:04:47 +0000620 memp_size = len;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700621 } else {
622
Christoph Hellwiga2357222019-06-13 09:09:02 +0200623 len = text_len + data_len + extra;
David Howells0f3e4422009-01-08 12:04:47 +0000624 len = PAGE_ALIGN(len);
Nicolas Pitre13c3f502016-07-24 11:30:15 -0400625 textpos = vm_mmap(NULL, 0, len,
Greg Ungerer72613e5f2007-02-07 12:03:08 +1000626 PROT_READ | PROT_EXEC | PROT_WRITE, MAP_PRIVATE, 0);
Greg Ungerer72613e5f2007-02-07 12:03:08 +1000627
Mike Frysinger0b8c78f2009-09-23 15:57:07 -0700628 if (!textpos || IS_ERR_VALUE(textpos)) {
Luke Yang1ad3dcc2006-03-25 03:08:24 -0800629 ret = textpos;
Nicolas Pitre13c3f502016-07-24 11:30:15 -0400630 if (!textpos)
631 ret = -ENOMEM;
Nicolas Pitre4adbb6a2016-07-24 11:30:16 -0400632 pr_err("Unable to allocate RAM for process text/data, "
Nicolas Pitre13c3f502016-07-24 11:30:15 -0400633 "errno %d\n", ret);
Andrew Mortondf889122006-05-20 15:00:01 -0700634 goto err;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700635 }
636
637 realdatastart = textpos + ntohl(hdr->data_start);
Christoph Hellwiga2357222019-06-13 09:09:02 +0200638 datapos = ALIGN(realdatastart, FLAT_DATA_ALIGN);
Oskar Schirmerc3dc5be2009-05-28 14:34:31 -0700639
Christoph Hellwig3b977712019-06-13 09:08:56 +0200640 reloc = (__be32 __user *)
Oskar Schirmerc3dc5be2009-05-28 14:34:31 -0700641 (datapos + (ntohl(hdr->reloc_start) - text_len));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700642 memp = textpos;
David Howells0f3e4422009-01-08 12:04:47 +0000643 memp_size = len;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700644#ifdef CONFIG_BINFMT_ZFLAT
645 /*
646 * load it all in and treat it like a RAM load from now on
647 */
648 if (flags & FLAT_FLAG_GZIP) {
Nicolas Pitre472f95f2016-07-24 11:30:26 -0400649#ifndef CONFIG_MMU
Nicolas Pitre13c3f502016-07-24 11:30:15 -0400650 result = decompress_exec(bprm, sizeof(struct flat_hdr),
651 (((char *)textpos) + sizeof(struct flat_hdr)),
Al Viro3dc20cb2013-04-13 20:31:37 -0400652 (text_len + full_data
Nicolas Pitre13c3f502016-07-24 11:30:15 -0400653 - sizeof(struct flat_hdr)),
Linus Torvalds1da177e2005-04-16 15:20:36 -0700654 0);
Christoph Hellwiga2357222019-06-13 09:09:02 +0200655 if (datapos != realdatastart)
656 memmove((void *)datapos, (void *)realdatastart,
657 full_data);
Nicolas Pitre472f95f2016-07-24 11:30:26 -0400658#else
659 /*
660 * This is used on MMU systems mainly for testing.
661 * Let's use a kernel buffer to simplify things.
662 */
663 long unz_text_len = text_len - sizeof(struct flat_hdr);
664 long unz_len = unz_text_len + full_data;
665 char *unz_data = vmalloc(unz_len);
666 if (!unz_data) {
667 result = -ENOMEM;
668 } else {
669 result = decompress_exec(bprm, sizeof(struct flat_hdr),
670 unz_data, unz_len, 0);
671 if (result == 0 &&
672 (copy_to_user((void __user *)textpos + sizeof(struct flat_hdr),
673 unz_data, unz_text_len) ||
674 copy_to_user((void __user *)datapos,
675 unz_data + unz_text_len, full_data)))
676 result = -EFAULT;
677 vfree(unz_data);
678 }
679#endif
Linus Torvalds1da177e2005-04-16 15:20:36 -0700680 } else if (flags & FLAT_FLAG_GZDATA) {
Al Viro3dc20cb2013-04-13 20:31:37 -0400681 result = read_code(bprm->file, textpos, 0, text_len);
Nicolas Pitre472f95f2016-07-24 11:30:26 -0400682 if (!IS_ERR_VALUE(result)) {
683#ifndef CONFIG_MMU
Linus Torvalds1da177e2005-04-16 15:20:36 -0700684 result = decompress_exec(bprm, text_len, (char *) datapos,
Al Viro3dc20cb2013-04-13 20:31:37 -0400685 full_data, 0);
Nicolas Pitre472f95f2016-07-24 11:30:26 -0400686#else
687 char *unz_data = vmalloc(full_data);
688 if (!unz_data) {
689 result = -ENOMEM;
690 } else {
691 result = decompress_exec(bprm, text_len,
692 unz_data, full_data, 0);
693 if (result == 0 &&
694 copy_to_user((void __user *)datapos,
695 unz_data, full_data))
696 result = -EFAULT;
697 vfree(unz_data);
698 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700699#endif
Nicolas Pitre472f95f2016-07-24 11:30:26 -0400700 }
701 } else
702#endif /* CONFIG_BINFMT_ZFLAT */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700703 {
Al Viro3dc20cb2013-04-13 20:31:37 -0400704 result = read_code(bprm->file, textpos, 0, text_len);
705 if (!IS_ERR_VALUE(result))
706 result = read_code(bprm->file, datapos,
707 ntohl(hdr->data_start),
708 full_data);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700709 }
Mike Frysinger0b8c78f2009-09-23 15:57:07 -0700710 if (IS_ERR_VALUE(result)) {
Nicolas Pitre13c3f502016-07-24 11:30:15 -0400711 ret = result;
Nicolas Pitre4adbb6a2016-07-24 11:30:16 -0400712 pr_err("Unable to read code+data+bss, errno %d\n", ret);
Christoph Hellwiga2357222019-06-13 09:09:02 +0200713 vm_munmap(textpos, text_len + data_len + extra);
Andrew Mortondf889122006-05-20 15:00:01 -0700714 goto err;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700715 }
716 }
717
Nicolas Pitre13c3f502016-07-24 11:30:15 -0400718 start_code = textpos + sizeof(struct flat_hdr);
719 end_code = textpos + text_len;
720 text_len -= sizeof(struct flat_hdr); /* the real code len */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700721
722 /* The main program needs a little extra setup in the task structure */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700723 if (id == 0) {
724 current->mm->start_code = start_code;
725 current->mm->end_code = end_code;
726 current->mm->start_data = datapos;
727 current->mm->end_data = datapos + data_len;
728 /*
729 * set up the brk stuff, uses any slack left in data/bss/stack
730 * allocation. We put the brk after the bss (between the bss
731 * and stack) like other platforms.
David Howells0f3e4422009-01-08 12:04:47 +0000732 * Userspace code relies on the stack pointer starting out at
733 * an address right at the end of a page.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700734 */
735 current->mm->start_brk = datapos + data_len + bss_len;
736 current->mm->brk = (current->mm->start_brk + 3) & ~3;
Nicolas Pitre015feac2016-07-24 11:30:25 -0400737#ifndef CONFIG_MMU
David Howells0f3e4422009-01-08 12:04:47 +0000738 current->mm->context.end_brk = memp + memp_size - stack_len;
Nicolas Pitre015feac2016-07-24 11:30:25 -0400739#endif
Linus Torvalds1da177e2005-04-16 15:20:36 -0700740 }
741
Nicolas Pitre13c3f502016-07-24 11:30:15 -0400742 if (flags & FLAT_FLAG_KTRACE) {
Nicolas Pitre4adbb6a2016-07-24 11:30:16 -0400743 pr_info("Mapping is %lx, Entry point is %x, data_start is %x\n",
744 textpos, 0x00ffffff&ntohl(hdr->entry), ntohl(hdr->data_start));
745 pr_info("%s %s: TEXT=%lx-%lx DATA=%lx-%lx BSS=%lx-%lx\n",
746 id ? "Lib" : "Load", bprm->filename,
747 start_code, end_code, datapos, datapos + data_len,
748 datapos + data_len, (datapos + data_len + bss_len + 3) & ~3);
Nicolas Pitre13c3f502016-07-24 11:30:15 -0400749 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700750
751 /* Store the current module values into the global library structure */
752 libinfo->lib_list[id].start_code = start_code;
753 libinfo->lib_list[id].start_data = datapos;
754 libinfo->lib_list[id].start_brk = datapos + data_len + bss_len;
755 libinfo->lib_list[id].text_len = text_len;
756 libinfo->lib_list[id].loaded = 1;
757 libinfo->lib_list[id].entry = (0x00ffffff & ntohl(hdr->entry)) + textpos;
758 libinfo->lib_list[id].build_date = ntohl(hdr->build_date);
Nicolas Pitre13c3f502016-07-24 11:30:15 -0400759
Linus Torvalds1da177e2005-04-16 15:20:36 -0700760 /*
761 * We just load the allocations into some temporary memory to
762 * help simplify all this mumbo jumbo
763 *
764 * We've got two different sections of relocation entries.
Lucas De Marchi25985ed2011-03-30 22:57:33 -0300765 * The first is the GOT which resides at the beginning of the data segment
Linus Torvalds1da177e2005-04-16 15:20:36 -0700766 * and is terminated with a -1. This one can be relocated in place.
767 * The second is the extra relocation entries tacked after the image's
768 * data segment. These require a little more processing as the entry is
769 * really an offset into the image which contains an offset into the
770 * image.
771 */
772 if (flags & FLAT_FLAG_GOTPIC) {
Al Viro468138d2017-05-02 19:52:17 -0400773 for (rp = (u32 __user *)datapos; ; rp++) {
774 u32 addr, rp_val;
Nicolas Pitre6e572ff2016-07-24 11:30:21 -0400775 if (get_user(rp_val, rp))
776 return -EFAULT;
777 if (rp_val == 0xffffffff)
778 break;
779 if (rp_val) {
780 addr = calc_reloc(rp_val, libinfo, id, 0);
Luke Yang1ad3dcc2006-03-25 03:08:24 -0800781 if (addr == RELOC_FAILED) {
782 ret = -ENOEXEC;
Andrew Mortondf889122006-05-20 15:00:01 -0700783 goto err;
Luke Yang1ad3dcc2006-03-25 03:08:24 -0800784 }
Nicolas Pitre6e572ff2016-07-24 11:30:21 -0400785 if (put_user(addr, rp))
786 return -EFAULT;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700787 }
788 }
789 }
790
791 /*
792 * Now run through the relocation entries.
793 * We've got to be careful here as C++ produces relocatable zero
794 * entries in the constructor and destructor tables which are then
795 * tested for being not zero (which will always occur unless we're
796 * based from address zero). This causes an endless loop as __start
797 * is at zero. The solution used is to not relocate zero addresses.
798 * This has the negative side effect of not allowing a global data
799 * reference to be statically initialised to _stext (I've moved
800 * __start to address 4 so that is okay).
801 */
802 if (rev > OLD_FLAT_VERSION) {
Nicolas Pitre13c3f502016-07-24 11:30:15 -0400803 for (i = 0; i < relocs; i++) {
Al Viro468138d2017-05-02 19:52:17 -0400804 u32 addr, relval;
Christoph Hellwig3b977712019-06-13 09:08:56 +0200805 __be32 tmp;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700806
Nicolas Pitre13c3f502016-07-24 11:30:15 -0400807 /*
808 * Get the address of the pointer to be
809 * relocated (of course, the address has to be
810 * relocated first).
811 */
Christoph Hellwig3b977712019-06-13 09:08:56 +0200812 if (get_user(tmp, reloc + i))
Nicolas Pitre6e572ff2016-07-24 11:30:21 -0400813 return -EFAULT;
Christoph Hellwig3b977712019-06-13 09:08:56 +0200814 relval = ntohl(tmp);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700815 addr = flat_get_relocate_addr(relval);
Al Viro468138d2017-05-02 19:52:17 -0400816 rp = (u32 __user *)calc_reloc(addr, libinfo, id, 1);
817 if (rp == (u32 __user *)RELOC_FAILED) {
Luke Yang1ad3dcc2006-03-25 03:08:24 -0800818 ret = -ENOEXEC;
Andrew Mortondf889122006-05-20 15:00:01 -0700819 goto err;
Luke Yang1ad3dcc2006-03-25 03:08:24 -0800820 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700821
822 /* Get the pointer's value. */
Christoph Hellwig6843d8a2019-06-13 09:09:00 +0200823 ret = flat_get_addr_from_rp(rp, relval, flags, &addr);
Al Viro468138d2017-05-02 19:52:17 -0400824 if (unlikely(ret))
825 goto err;
826
Linus Torvalds1da177e2005-04-16 15:20:36 -0700827 if (addr != 0) {
828 /*
829 * Do the relocation. PIC relocs in the data section are
830 * already in target order
831 */
Christoph Hellwig3b977712019-06-13 09:08:56 +0200832 if ((flags & FLAT_FLAG_GOTPIC) == 0) {
833 /*
834 * Meh, the same value can have a different
835 * byte order based on a flag..
836 */
837 addr = ntohl((__force __be32)addr);
838 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700839 addr = calc_reloc(addr, libinfo, id, 0);
Luke Yang1ad3dcc2006-03-25 03:08:24 -0800840 if (addr == RELOC_FAILED) {
841 ret = -ENOEXEC;
Andrew Mortondf889122006-05-20 15:00:01 -0700842 goto err;
Luke Yang1ad3dcc2006-03-25 03:08:24 -0800843 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700844
845 /* Write back the relocated pointer. */
Al Viro468138d2017-05-02 19:52:17 -0400846 ret = flat_put_addr_at_rp(rp, addr, relval);
847 if (unlikely(ret))
848 goto err;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700849 }
850 }
Christoph Hellwigcf9a5662019-06-13 09:08:58 +0200851#ifdef CONFIG_BINFMT_FLAT_OLD
Linus Torvalds1da177e2005-04-16 15:20:36 -0700852 } else {
Nicolas Pitre1b2ce442016-07-24 11:30:22 -0400853 for (i = 0; i < relocs; i++) {
Christoph Hellwig3b977712019-06-13 09:08:56 +0200854 __be32 relval;
Nicolas Pitre1b2ce442016-07-24 11:30:22 -0400855 if (get_user(relval, reloc + i))
856 return -EFAULT;
Christoph Hellwig3b977712019-06-13 09:08:56 +0200857 old_reloc(ntohl(relval));
Nicolas Pitre1b2ce442016-07-24 11:30:22 -0400858 }
Christoph Hellwigcf9a5662019-06-13 09:08:58 +0200859#endif /* CONFIG_BINFMT_FLAT_OLD */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700860 }
Nicolas Pitre13c3f502016-07-24 11:30:15 -0400861
Christoph Hellwig79ef1e12020-06-07 21:42:46 -0700862 flush_icache_user_range(start_code, end_code);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700863
864 /* zero the BSS, BRK and stack areas */
Nicolas Pitre467aa142016-07-24 11:30:23 -0400865 if (clear_user((void __user *)(datapos + data_len), bss_len +
866 (memp + memp_size - stack_len - /* end brk */
867 libinfo->lib_list[id].start_brk) + /* start brk */
868 stack_len))
869 return -EFAULT;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700870
871 return 0;
Luke Yang1ad3dcc2006-03-25 03:08:24 -0800872err:
873 return ret;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700874}
875
876
877/****************************************************************************/
878#ifdef CONFIG_BINFMT_SHARED_FLAT
879
880/*
881 * Load a shared library into memory. The library gets its own data
882 * segment (including bss) but not argv/argc/environ.
883 */
884
885static int load_flat_shared_library(int id, struct lib_info *libs)
886{
Jann Horn867bfa42019-06-28 12:06:46 -0700887 /*
888 * This is a fake bprm struct; only the members "buf", "file" and
889 * "filename" are actually used.
890 */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700891 struct linux_binprm bprm;
892 int res;
893 char buf[16];
Jann Horn867bfa42019-06-28 12:06:46 -0700894 loff_t pos = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700895
David Howells3a852d32011-04-28 16:26:38 +0100896 memset(&bprm, 0, sizeof(bprm));
897
Linus Torvalds1da177e2005-04-16 15:20:36 -0700898 /* Create the file name */
899 sprintf(buf, "/lib/lib%d.so", id);
900
901 /* Open the file up */
902 bprm.filename = buf;
903 bprm.file = open_exec(bprm.filename);
904 res = PTR_ERR(bprm.file);
905 if (IS_ERR(bprm.file))
906 return res;
907
Jann Horn867bfa42019-06-28 12:06:46 -0700908 res = kernel_read(bprm.file, bprm.buf, BINPRM_BUF_SIZE, &pos);
Linus Torvalds34406252009-08-06 15:09:34 -0700909
Jann Horn867bfa42019-06-28 12:06:46 -0700910 if (res >= 0)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700911 res = load_flat_file(&bprm, libs, id, NULL);
Linus Torvalds34406252009-08-06 15:09:34 -0700912
Linus Torvalds34406252009-08-06 15:09:34 -0700913 allow_write_access(bprm.file);
914 fput(bprm.file);
915
Nicolas Pitre13c3f502016-07-24 11:30:15 -0400916 return res;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700917}
918
919#endif /* CONFIG_BINFMT_SHARED_FLAT */
920/****************************************************************************/
921
922/*
923 * These are the functions used to load flat style executables and shared
924 * libraries. There is no binary dependent code anywhere else.
925 */
926
Nicolas Pitre13c3f502016-07-24 11:30:15 -0400927static int load_flat_binary(struct linux_binprm *bprm)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700928{
929 struct lib_info libinfo;
Al Viro71613c32012-10-20 22:00:48 -0400930 struct pt_regs *regs = current_pt_regs();
Nicolas Pitre015feac2016-07-24 11:30:25 -0400931 unsigned long stack_len = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700932 unsigned long start_addr;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700933 int res;
934 int i, j;
935
936 memset(&libinfo, 0, sizeof(libinfo));
Nicolas Pitre13c3f502016-07-24 11:30:15 -0400937
Linus Torvalds1da177e2005-04-16 15:20:36 -0700938 /*
939 * We have to add the size of our arguments to our stack size
940 * otherwise it's too easy for users to create stack overflows
941 * by passing in a huge argument list. And yes, we have to be
942 * pedantic and include space for the argv/envp array as it may have
943 * a lot of entries.
944 */
Nicolas Pitre015feac2016-07-24 11:30:25 -0400945#ifndef CONFIG_MMU
946 stack_len += PAGE_SIZE * MAX_ARG_PAGES - bprm->p; /* the strings */
947#endif
Nicolas Pitrea97d1572016-07-24 11:30:20 -0400948 stack_len += (bprm->argc + 1) * sizeof(char *); /* the argv array */
949 stack_len += (bprm->envc + 1) * sizeof(char *); /* the envp array */
950 stack_len = ALIGN(stack_len, FLAT_STACK_ALIGN);
Nicolas Pitre13c3f502016-07-24 11:30:15 -0400951
Linus Torvalds1da177e2005-04-16 15:20:36 -0700952 res = load_flat_file(bprm, &libinfo, 0, &stack_len);
Arnd Bergmann287980e2016-05-27 23:23:25 +0200953 if (res < 0)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700954 return res;
Nicolas Pitre13c3f502016-07-24 11:30:15 -0400955
Linus Torvalds1da177e2005-04-16 15:20:36 -0700956 /* Update data segment pointers for all libraries */
Nicolas Pitreaf521f92016-07-24 11:30:24 -0400957 for (i = 0; i < MAX_SHARED_LIBS; i++) {
958 if (!libinfo.lib_list[i].loaded)
959 continue;
960 for (j = 0; j < MAX_SHARED_LIBS; j++) {
961 unsigned long val = libinfo.lib_list[j].loaded ?
962 libinfo.lib_list[j].start_data : UNLOADED_LIB;
963 unsigned long __user *p = (unsigned long __user *)
964 libinfo.lib_list[i].start_data;
965 p -= j + 1;
966 if (put_user(val, p))
967 return -EFAULT;
968 }
969 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700970
Linus Torvalds1da177e2005-04-16 15:20:36 -0700971 set_binfmt(&flat_format);
972
Nicolas Pitre015feac2016-07-24 11:30:25 -0400973#ifdef CONFIG_MMU
974 res = setup_arg_pages(bprm, STACK_TOP, EXSTACK_DEFAULT);
975 if (!res)
976 res = create_flat_tables(bprm, bprm->p);
977#else
Nicolas Pitrea97d1572016-07-24 11:30:20 -0400978 /* Stash our initial stack pointer into the mm structure */
979 current->mm->start_stack =
980 ((current->mm->context.end_brk + stack_len + 3) & ~3) - 4;
981 pr_debug("sp=%lx\n", current->mm->start_stack);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700982
Nicolas Pitre687fd772016-07-24 11:30:19 -0400983 /* copy the arg pages onto the stack */
Nicolas Pitrea97d1572016-07-24 11:30:20 -0400984 res = transfer_args_to_stack(bprm, &current->mm->start_stack);
985 if (!res)
986 res = create_flat_tables(bprm, current->mm->start_stack);
Nicolas Pitre015feac2016-07-24 11:30:25 -0400987#endif
Nicolas Pitre687fd772016-07-24 11:30:19 -0400988 if (res)
989 return res;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700990
Linus Torvalds1da177e2005-04-16 15:20:36 -0700991 /* Fake some return addresses to ensure the call chain will
992 * initialise library in order for us. We are required to call
993 * lib 1 first, then 2, ... and finally the main program (id 0).
994 */
995 start_addr = libinfo.lib_list[0].entry;
996
997#ifdef CONFIG_BINFMT_SHARED_FLAT
Nicolas Pitre13c3f502016-07-24 11:30:15 -0400998 for (i = MAX_SHARED_LIBS-1; i > 0; i--) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700999 if (libinfo.lib_list[i].loaded) {
1000 /* Push previos first to call address */
Nicolas Pitrea97d1572016-07-24 11:30:20 -04001001 unsigned long __user *sp;
1002 current->mm->start_stack -= sizeof(unsigned long);
1003 sp = (unsigned long __user *)current->mm->start_stack;
Al Viro8861fd572020-02-19 09:32:55 -05001004 if (put_user(start_addr, sp))
1005 return -EFAULT;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001006 start_addr = libinfo.lib_list[i].entry;
1007 }
1008 }
1009#endif
Nicolas Pitre13c3f502016-07-24 11:30:15 -04001010
Takashi YOSHII74c27c42008-08-11 20:10:54 +09001011#ifdef FLAT_PLAT_INIT
1012 FLAT_PLAT_INIT(regs);
1013#endif
Nicolas Pitre13c3f502016-07-24 11:30:15 -04001014
Kees Cookb8383832018-04-10 16:34:57 -07001015 finalize_exec(bprm);
Nicolas Pitre4adbb6a2016-07-24 11:30:16 -04001016 pr_debug("start_thread(regs=0x%p, entry=0x%lx, start_stack=0x%lx)\n",
1017 regs, start_addr, current->mm->start_stack);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001018 start_thread(regs, start_addr, current->mm->start_stack);
1019
Linus Torvalds1da177e2005-04-16 15:20:36 -07001020 return 0;
1021}
1022
1023/****************************************************************************/
1024
1025static int __init init_flat_binfmt(void)
1026{
Al Viro8fc3dc52012-03-17 03:05:16 -04001027 register_binfmt(&flat_format);
1028 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001029}
Linus Torvalds1da177e2005-04-16 15:20:36 -07001030core_initcall(init_flat_binfmt);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001031
1032/****************************************************************************/