blob: 5d6b94475f272629dc3f8c252749aff08790766d [file] [log] [blame]
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>
Linus Torvalds1da177e2005-04-16 15:20:36 -070045
46/****************************************************************************/
47
Oskar Schirmerc3dc5be2009-05-28 14:34:31 -070048/*
Mike Frysinger2e94de82010-06-04 14:14:53 -070049 * User data (data section and bss) needs to be aligned.
50 * We pick 0x20 here because it is the max value elf2flt has always
51 * used in producing FLAT files, and because it seems to be large
52 * enough to make all the gcc alignment related tests happy.
53 */
54#define FLAT_DATA_ALIGN (0x20)
55
56/*
57 * User data (stack) also needs to be aligned.
58 * Here we can be a bit looser than the data sections since this
59 * needs to only meet arch ABI requirements.
Oskar Schirmerc3dc5be2009-05-28 14:34:31 -070060 */
Mike Frysinger29520952010-06-29 15:05:21 -070061#define FLAT_STACK_ALIGN max_t(unsigned long, sizeof(void *), ARCH_SLAB_MINALIGN)
Oskar Schirmerc3dc5be2009-05-28 14:34:31 -070062
Linus Torvalds1da177e2005-04-16 15:20:36 -070063#define RELOC_FAILED 0xff00ff01 /* Relocation incorrect somewhere */
64#define UNLOADED_LIB 0x7ff000ff /* Placeholder for unused library */
65
66struct lib_info {
67 struct {
68 unsigned long start_code; /* Start of text segment */
69 unsigned long start_data; /* Start of data segment */
70 unsigned long start_brk; /* End of data segment */
71 unsigned long text_len; /* Length of text segment */
72 unsigned long entry; /* Start address for this module */
73 unsigned long build_date; /* When this one was compiled */
Nicolas Pitre13c3f502016-07-24 11:30:15 -040074 bool loaded; /* Has this library been loaded? */
Linus Torvalds1da177e2005-04-16 15:20:36 -070075 } lib_list[MAX_SHARED_LIBS];
76};
77
78#ifdef CONFIG_BINFMT_SHARED_FLAT
79static int load_flat_shared_library(int id, struct lib_info *p);
80#endif
81
Al Viro71613c32012-10-20 22:00:48 -040082static int load_flat_binary(struct linux_binprm *);
Masami Hiramatsuf6151df2009-12-17 15:27:16 -080083static int flat_core_dump(struct coredump_params *cprm);
Linus Torvalds1da177e2005-04-16 15:20:36 -070084
Linus Torvalds1da177e2005-04-16 15:20:36 -070085static struct linux_binfmt flat_format = {
86 .module = THIS_MODULE,
87 .load_binary = load_flat_binary,
88 .core_dump = flat_core_dump,
89 .min_coredump = PAGE_SIZE
90};
91
92/****************************************************************************/
93/*
94 * Routine writes a core dump image in the current directory.
95 * Currently only a stub-function.
96 */
97
Masami Hiramatsuf6151df2009-12-17 15:27:16 -080098static int flat_core_dump(struct coredump_params *cprm)
Linus Torvalds1da177e2005-04-16 15:20:36 -070099{
Nicolas Pitre4adbb6a2016-07-24 11:30:16 -0400100 pr_warn("Process %s:%d received signr %d and should have core dumped\n",
101 current->comm, current->pid, cprm->siginfo->si_signo);
Nicolas Pitre13c3f502016-07-24 11:30:15 -0400102 return 1;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700103}
104
105/****************************************************************************/
106/*
107 * create_flat_tables() parses the env- and arg-strings in new user
108 * memory and creates the pointer tables from them, and puts their
Nicolas Pitrea97d1572016-07-24 11:30:20 -0400109 * addresses on the "stack", recording the new stack pointer value.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700110 */
111
Nicolas Pitrea97d1572016-07-24 11:30:20 -0400112static int create_flat_tables(struct linux_binprm *bprm, unsigned long arg_start)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700113{
Nicolas Pitrea97d1572016-07-24 11:30:20 -0400114 char __user *p;
115 unsigned long __user *sp;
116 long i, len;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700117
Nicolas Pitrea97d1572016-07-24 11:30:20 -0400118 p = (char __user *)arg_start;
119 sp = (unsigned long __user *)current->mm->start_stack;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700120
Nicolas Pitrea97d1572016-07-24 11:30:20 -0400121 sp -= bprm->envc + 1;
122 sp -= bprm->argc + 1;
123 sp -= flat_argvp_envp_on_stack() ? 2 : 0;
124 sp -= 1; /* &argc */
125
126 current->mm->start_stack = (unsigned long)sp & -FLAT_STACK_ALIGN;
127 sp = (unsigned long __user *)current->mm->start_stack;
128
129 __put_user(bprm->argc, sp++);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700130 if (flat_argvp_envp_on_stack()) {
Nicolas Pitrea97d1572016-07-24 11:30:20 -0400131 unsigned long argv, envp;
132 argv = (unsigned long)(sp + 2);
133 envp = (unsigned long)(sp + 2 + bprm->argc + 1);
134 __put_user(argv, sp++);
135 __put_user(envp, sp++);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700136 }
137
Nicolas Pitrea97d1572016-07-24 11:30:20 -0400138 current->mm->arg_start = (unsigned long)p;
139 for (i = bprm->argc; i > 0; i--) {
140 __put_user((unsigned long)p, sp++);
141 len = strnlen_user(p, MAX_ARG_STRLEN);
142 if (!len || len > MAX_ARG_STRLEN)
143 return -EINVAL;
144 p += len;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700145 }
Nicolas Pitrea97d1572016-07-24 11:30:20 -0400146 __put_user(0, sp++);
147 current->mm->arg_end = (unsigned long)p;
148
149 current->mm->env_start = (unsigned long) p;
150 for (i = bprm->envc; i > 0; i--) {
151 __put_user((unsigned long)p, sp++);
152 len = strnlen_user(p, MAX_ARG_STRLEN);
153 if (!len || len > MAX_ARG_STRLEN)
154 return -EINVAL;
155 p += len;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700156 }
Nicolas Pitrea97d1572016-07-24 11:30:20 -0400157 __put_user(0, sp++);
158 current->mm->env_end = (unsigned long)p;
159
160 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700161}
162
163/****************************************************************************/
164
165#ifdef CONFIG_BINFMT_ZFLAT
166
167#include <linux/zlib.h>
168
169#define LBUFSIZE 4000
170
171/* gzip flag byte */
172#define ASCII_FLAG 0x01 /* bit 0 set: file probably ASCII text */
173#define CONTINUATION 0x02 /* bit 1 set: continuation of multi-part gzip file */
174#define EXTRA_FIELD 0x04 /* bit 2 set: extra field present */
175#define ORIG_NAME 0x08 /* bit 3 set: original file name present */
176#define COMMENT 0x10 /* bit 4 set: file comment present */
177#define ENCRYPTED 0x20 /* bit 5 set: file is encrypted */
178#define RESERVED 0xC0 /* bit 6,7: reserved */
179
Christoph Hellwigbdd1d2d2017-09-01 17:39:13 +0200180static int decompress_exec(struct linux_binprm *bprm, loff_t fpos, char *dst,
181 long len, int fd)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700182{
183 unsigned char *buf;
184 z_stream strm;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700185 int ret, retval;
186
Christoph Hellwigbdd1d2d2017-09-01 17:39:13 +0200187 pr_debug("decompress_exec(offset=%llx,buf=%p,len=%lx)\n", fpos, dst, len);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700188
189 memset(&strm, 0, sizeof(strm));
190 strm.workspace = kmalloc(zlib_inflate_workspacesize(), GFP_KERNEL);
Markus Elfring9367bb72017-09-08 16:16:14 -0700191 if (!strm.workspace)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700192 return -ENOMEM;
Markus Elfring9367bb72017-09-08 16:16:14 -0700193
Linus Torvalds1da177e2005-04-16 15:20:36 -0700194 buf = kmalloc(LBUFSIZE, GFP_KERNEL);
Markus Elfring9367bb72017-09-08 16:16:14 -0700195 if (!buf) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700196 retval = -ENOMEM;
197 goto out_free;
198 }
199
200 /* Read in first chunk of data and parse gzip header. */
Christoph Hellwigbdd1d2d2017-09-01 17:39:13 +0200201 ret = kernel_read(bprm->file, buf, LBUFSIZE, &fpos);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700202
203 strm.next_in = buf;
204 strm.avail_in = ret;
205 strm.total_in = 0;
206
207 retval = -ENOEXEC;
208
209 /* Check minimum size -- gzip header */
210 if (ret < 10) {
Nicolas Pitre4adbb6a2016-07-24 11:30:16 -0400211 pr_debug("file too small?\n");
Linus Torvalds1da177e2005-04-16 15:20:36 -0700212 goto out_free_buf;
213 }
214
215 /* Check gzip magic number */
216 if ((buf[0] != 037) || ((buf[1] != 0213) && (buf[1] != 0236))) {
Nicolas Pitre4adbb6a2016-07-24 11:30:16 -0400217 pr_debug("unknown compression magic?\n");
Linus Torvalds1da177e2005-04-16 15:20:36 -0700218 goto out_free_buf;
219 }
220
221 /* Check gzip method */
222 if (buf[2] != 8) {
Nicolas Pitre4adbb6a2016-07-24 11:30:16 -0400223 pr_debug("unknown compression method?\n");
Linus Torvalds1da177e2005-04-16 15:20:36 -0700224 goto out_free_buf;
225 }
226 /* Check gzip flags */
227 if ((buf[3] & ENCRYPTED) || (buf[3] & CONTINUATION) ||
228 (buf[3] & RESERVED)) {
Nicolas Pitre4adbb6a2016-07-24 11:30:16 -0400229 pr_debug("unknown flags?\n");
Linus Torvalds1da177e2005-04-16 15:20:36 -0700230 goto out_free_buf;
231 }
232
233 ret = 10;
234 if (buf[3] & EXTRA_FIELD) {
235 ret += 2 + buf[10] + (buf[11] << 8);
Nicolas Pitre13c3f502016-07-24 11:30:15 -0400236 if (unlikely(ret >= LBUFSIZE)) {
Nicolas Pitre4adbb6a2016-07-24 11:30:16 -0400237 pr_debug("buffer overflow (EXTRA)?\n");
Linus Torvalds1da177e2005-04-16 15:20:36 -0700238 goto out_free_buf;
239 }
240 }
241 if (buf[3] & ORIG_NAME) {
Volodymyr G. Lukiianykf4cfb182008-10-15 22:01:15 -0700242 while (ret < LBUFSIZE && buf[ret++] != 0)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700243 ;
Nicolas Pitre13c3f502016-07-24 11:30:15 -0400244 if (unlikely(ret == LBUFSIZE)) {
Nicolas Pitre4adbb6a2016-07-24 11:30:16 -0400245 pr_debug("buffer overflow (ORIG_NAME)?\n");
Linus Torvalds1da177e2005-04-16 15:20:36 -0700246 goto out_free_buf;
247 }
248 }
249 if (buf[3] & COMMENT) {
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 (COMMENT)?\n");
Linus Torvalds1da177e2005-04-16 15:20:36 -0700254 goto out_free_buf;
255 }
256 }
257
258 strm.next_in += ret;
259 strm.avail_in -= ret;
260
261 strm.next_out = dst;
262 strm.avail_out = len;
263 strm.total_out = 0;
264
265 if (zlib_inflateInit2(&strm, -MAX_WBITS) != Z_OK) {
Nicolas Pitre4adbb6a2016-07-24 11:30:16 -0400266 pr_debug("zlib init failed?\n");
Linus Torvalds1da177e2005-04-16 15:20:36 -0700267 goto out_free_buf;
268 }
269
270 while ((ret = zlib_inflate(&strm, Z_NO_FLUSH)) == Z_OK) {
Christoph Hellwigbdd1d2d2017-09-01 17:39:13 +0200271 ret = kernel_read(bprm->file, buf, LBUFSIZE, &fpos);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700272 if (ret <= 0)
273 break;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700274 len -= ret;
275
276 strm.next_in = buf;
277 strm.avail_in = ret;
278 strm.total_in = 0;
279 }
280
281 if (ret < 0) {
Nicolas Pitre4adbb6a2016-07-24 11:30:16 -0400282 pr_debug("decompression failed (%d), %s\n",
Linus Torvalds1da177e2005-04-16 15:20:36 -0700283 ret, strm.msg);
284 goto out_zlib;
285 }
286
287 retval = 0;
288out_zlib:
289 zlib_inflateEnd(&strm);
290out_free_buf:
291 kfree(buf);
292out_free:
293 kfree(strm.workspace);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700294 return retval;
295}
296
297#endif /* CONFIG_BINFMT_ZFLAT */
298
299/****************************************************************************/
300
301static unsigned long
302calc_reloc(unsigned long r, struct lib_info *p, int curid, int internalp)
303{
304 unsigned long addr;
305 int id;
306 unsigned long start_brk;
307 unsigned long start_data;
308 unsigned long text_len;
309 unsigned long start_code;
310
311#ifdef CONFIG_BINFMT_SHARED_FLAT
312 if (r == 0)
313 id = curid; /* Relocs of 0 are always self referring */
314 else {
315 id = (r >> 24) & 0xff; /* Find ID for this reloc */
316 r &= 0x00ffffff; /* Trim ID off here */
317 }
318 if (id >= MAX_SHARED_LIBS) {
Nicolas Pitre4adbb6a2016-07-24 11:30:16 -0400319 pr_err("reference 0x%lx to shared library %d", r, id);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700320 goto failed;
321 }
322 if (curid != id) {
323 if (internalp) {
Nicolas Pitre4adbb6a2016-07-24 11:30:16 -0400324 pr_err("reloc address 0x%lx not in same module "
325 "(%d != %d)", r, curid, id);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700326 goto failed;
Nicolas Pitre13c3f502016-07-24 11:30:15 -0400327 } else if (!p->lib_list[id].loaded &&
328 load_flat_shared_library(id, p) < 0) {
Nicolas Pitre4adbb6a2016-07-24 11:30:16 -0400329 pr_err("failed to load library %d", id);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700330 goto failed;
331 }
332 /* Check versioning information (i.e. time stamps) */
333 if (p->lib_list[id].build_date && p->lib_list[curid].build_date &&
334 p->lib_list[curid].build_date < p->lib_list[id].build_date) {
Nicolas Pitre4adbb6a2016-07-24 11:30:16 -0400335 pr_err("library %d is younger than %d", id, curid);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700336 goto failed;
337 }
338 }
339#else
340 id = 0;
341#endif
342
343 start_brk = p->lib_list[id].start_brk;
344 start_data = p->lib_list[id].start_data;
345 start_code = p->lib_list[id].start_code;
346 text_len = p->lib_list[id].text_len;
347
348 if (!flat_reloc_valid(r, start_brk - start_data + text_len)) {
Nicolas Pitre4adbb6a2016-07-24 11:30:16 -0400349 pr_err("reloc outside program 0x%lx (0 - 0x%lx/0x%lx)",
Nicolas Pitre13c3f502016-07-24 11:30:15 -0400350 r, start_brk-start_data+text_len, text_len);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700351 goto failed;
352 }
353
354 if (r < text_len) /* In text segment */
355 addr = r + start_code;
356 else /* In data segment */
357 addr = r - text_len + start_data;
358
359 /* Range checked already above so doing the range tests is redundant...*/
Nicolas Pitre13c3f502016-07-24 11:30:15 -0400360 return addr;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700361
362failed:
Nicolas Pitre4adbb6a2016-07-24 11:30:16 -0400363 pr_cont(", killing %s!\n", current->comm);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700364 send_sig(SIGSEGV, current, 0);
365
366 return RELOC_FAILED;
367}
368
369/****************************************************************************/
370
Axel Lin34303432014-06-04 16:12:15 -0700371static void old_reloc(unsigned long rl)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700372{
Nicolas Pitre13c3f502016-07-24 11:30:15 -0400373 static const char *segment[] = { "TEXT", "DATA", "BSS", "*UNKNOWN*" };
Linus Torvalds1da177e2005-04-16 15:20:36 -0700374 flat_v2_reloc_t r;
Nicolas Pitre1b2ce442016-07-24 11:30:22 -0400375 unsigned long __user *ptr;
376 unsigned long val;
Nicolas Pitre13c3f502016-07-24 11:30:15 -0400377
Linus Torvalds1da177e2005-04-16 15:20:36 -0700378 r.value = rl;
379#if defined(CONFIG_COLDFIRE)
Nicolas Pitre1b2ce442016-07-24 11:30:22 -0400380 ptr = (unsigned long __user *)(current->mm->start_code + r.reloc.offset);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700381#else
Nicolas Pitre1b2ce442016-07-24 11:30:22 -0400382 ptr = (unsigned long __user *)(current->mm->start_data + r.reloc.offset);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700383#endif
Nicolas Pitre1b2ce442016-07-24 11:30:22 -0400384 get_user(val, ptr);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700385
Nicolas Pitre4adbb6a2016-07-24 11:30:16 -0400386 pr_debug("Relocation of variable at DATASEG+%x "
387 "(address %p, currently %lx) into segment %s\n",
Nicolas Pitre1b2ce442016-07-24 11:30:22 -0400388 r.reloc.offset, ptr, val, segment[r.reloc.type]);
Nicolas Pitre13c3f502016-07-24 11:30:15 -0400389
Linus Torvalds1da177e2005-04-16 15:20:36 -0700390 switch (r.reloc.type) {
391 case OLD_FLAT_RELOC_TYPE_TEXT:
Nicolas Pitre1b2ce442016-07-24 11:30:22 -0400392 val += current->mm->start_code;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700393 break;
394 case OLD_FLAT_RELOC_TYPE_DATA:
Nicolas Pitre1b2ce442016-07-24 11:30:22 -0400395 val += current->mm->start_data;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700396 break;
397 case OLD_FLAT_RELOC_TYPE_BSS:
Nicolas Pitre1b2ce442016-07-24 11:30:22 -0400398 val += current->mm->end_data;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700399 break;
400 default:
Nicolas Pitre4adbb6a2016-07-24 11:30:16 -0400401 pr_err("Unknown relocation type=%x\n", r.reloc.type);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700402 break;
403 }
Nicolas Pitre1b2ce442016-07-24 11:30:22 -0400404 put_user(val, ptr);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700405
Nicolas Pitre1b2ce442016-07-24 11:30:22 -0400406 pr_debug("Relocation became %lx\n", val);
Nicolas Pitre13c3f502016-07-24 11:30:15 -0400407}
Linus Torvalds1da177e2005-04-16 15:20:36 -0700408
409/****************************************************************************/
410
Nicolas Pitre13c3f502016-07-24 11:30:15 -0400411static int load_flat_file(struct linux_binprm *bprm,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700412 struct lib_info *libinfo, int id, unsigned long *extra_stack)
413{
Nicolas Pitre13c3f502016-07-24 11:30:15 -0400414 struct flat_hdr *hdr;
415 unsigned long textpos, datapos, realdatastart;
Al Viro468138d2017-05-02 19:52:17 -0400416 u32 text_len, data_len, bss_len, stack_len, full_data, flags;
Nicolas Pitre13c3f502016-07-24 11:30:15 -0400417 unsigned long len, memp, memp_size, extra, rlim;
Al Viro468138d2017-05-02 19:52:17 -0400418 u32 __user *reloc, *rp;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700419 struct inode *inode;
Nicolas Pitre13c3f502016-07-24 11:30:15 -0400420 int i, rev, relocs;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700421 loff_t fpos;
422 unsigned long start_code, end_code;
Nicolas Pitre13c3f502016-07-24 11:30:15 -0400423 ssize_t result;
Luke Yang1ad3dcc2006-03-25 03:08:24 -0800424 int ret;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700425
426 hdr = ((struct flat_hdr *) bprm->buf); /* exec-header */
Al Viro496ad9a2013-01-23 17:07:38 -0500427 inode = file_inode(bprm->file);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700428
429 text_len = ntohl(hdr->data_start);
430 data_len = ntohl(hdr->data_end) - ntohl(hdr->data_start);
431 bss_len = ntohl(hdr->bss_end) - ntohl(hdr->data_end);
432 stack_len = ntohl(hdr->stack_size);
433 if (extra_stack) {
434 stack_len += *extra_stack;
435 *extra_stack = stack_len;
436 }
437 relocs = ntohl(hdr->reloc_count);
438 flags = ntohl(hdr->flags);
439 rev = ntohl(hdr->rev);
Al Viro3dc20cb2013-04-13 20:31:37 -0400440 full_data = data_len + relocs * sizeof(unsigned long);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700441
Greg Ungerer845884d2006-01-10 16:59:37 +1000442 if (strncmp(hdr->magic, "bFLT", 4)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700443 /*
Mike Frysingere2a366d2008-02-14 19:31:29 -0800444 * Previously, here was a printk to tell people
445 * "BINFMT_FLAT: bad header magic".
446 * But for the kernel which also use ELF FD-PIC format, this
447 * error message is confusing.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700448 * because a lot of people do not manage to produce good
Linus Torvalds1da177e2005-04-16 15:20:36 -0700449 */
Luke Yang1ad3dcc2006-03-25 03:08:24 -0800450 ret = -ENOEXEC;
451 goto err;
Greg Ungerer845884d2006-01-10 16:59:37 +1000452 }
453
454 if (flags & FLAT_FLAG_KTRACE)
Nicolas Pitre4adbb6a2016-07-24 11:30:16 -0400455 pr_info("Loading file: %s\n", bprm->filename);
Greg Ungerer845884d2006-01-10 16:59:37 +1000456
457 if (rev != FLAT_VERSION && rev != OLD_FLAT_VERSION) {
Nicolas Pitre4adbb6a2016-07-24 11:30:16 -0400458 pr_err("bad flat file version 0x%x (supported 0x%lx and 0x%lx)\n",
459 rev, FLAT_VERSION, OLD_FLAT_VERSION);
Luke Yang1ad3dcc2006-03-25 03:08:24 -0800460 ret = -ENOEXEC;
461 goto err;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700462 }
Nicolas Pitre13c3f502016-07-24 11:30:15 -0400463
Linus Torvalds1da177e2005-04-16 15:20:36 -0700464 /* Don't allow old format executables to use shared libraries */
465 if (rev == OLD_FLAT_VERSION && id != 0) {
Nicolas Pitre4adbb6a2016-07-24 11:30:16 -0400466 pr_err("shared libraries are not available before rev 0x%lx\n",
467 FLAT_VERSION);
Luke Yang1ad3dcc2006-03-25 03:08:24 -0800468 ret = -ENOEXEC;
469 goto err;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700470 }
471
472 /*
Nicolas Pitrec995ee22016-07-24 11:30:17 -0400473 * Make sure the header params are sane.
474 * 28 bits (256 MB) is way more than reasonable in this case.
475 * If some top bits are set we have probable binary corruption.
476 */
477 if ((text_len | data_len | bss_len | stack_len | full_data) >> 28) {
478 pr_err("bad header\n");
479 ret = -ENOEXEC;
480 goto err;
481 }
482
483 /*
Linus Torvalds1da177e2005-04-16 15:20:36 -0700484 * fix up the flags for the older format, there were all kinds
485 * of endian hacks, this only works for the simple cases
486 */
487 if (rev == OLD_FLAT_VERSION && flat_old_ram_flag(flags))
488 flags = FLAT_FLAG_RAM;
489
490#ifndef CONFIG_BINFMT_ZFLAT
491 if (flags & (FLAT_FLAG_GZIP|FLAT_FLAG_GZDATA)) {
Nicolas Pitre4adbb6a2016-07-24 11:30:16 -0400492 pr_err("Support for ZFLAT executables is not enabled.\n");
Luke Yang1ad3dcc2006-03-25 03:08:24 -0800493 ret = -ENOEXEC;
494 goto err;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700495 }
496#endif
497
498 /*
499 * Check initial limits. This avoids letting people circumvent
500 * size limits imposed on them by creating programs with large
501 * arrays in the data or bss.
502 */
Jiri Slabyd554ed892010-03-05 13:42:42 -0800503 rlim = rlimit(RLIMIT_DATA);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700504 if (rlim >= RLIM_INFINITY)
505 rlim = ~0;
Luke Yang1ad3dcc2006-03-25 03:08:24 -0800506 if (data_len + bss_len > rlim) {
507 ret = -ENOMEM;
508 goto err;
509 }
510
Linus Torvalds1da177e2005-04-16 15:20:36 -0700511 /* Flush all traces of the currently running executable */
512 if (id == 0) {
Nicolas Pitre13c3f502016-07-24 11:30:15 -0400513 ret = flush_old_exec(bprm);
514 if (ret)
Andrew Mortondf889122006-05-20 15:00:01 -0700515 goto err;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700516
517 /* OK, This is the point of no return */
Malcolm Parsonsfcc18e82006-06-26 11:49:41 +1000518 set_personality(PER_LINUX_32BIT);
Linus Torvalds221af7f2010-01-28 22:14:42 -0800519 setup_new_exec(bprm);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700520 }
521
522 /*
523 * calculate the extra space we need to map in
524 */
Andrew Morton0e647c02007-10-16 23:27:26 -0700525 extra = max_t(unsigned long, bss_len + stack_len,
526 relocs * sizeof(unsigned long));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700527
528 /*
529 * there are a couple of cases here, the separate code/data
530 * case, and then the fully copied to RAM case which lumps
531 * it all together.
532 */
Nicolas Pitre015feac2016-07-24 11:30:25 -0400533 if (!IS_ENABLED(CONFIG_MMU) && !(flags & (FLAT_FLAG_RAM|FLAT_FLAG_GZIP))) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700534 /*
535 * this should give us a ROM ptr, but if it doesn't we don't
536 * really care
537 */
Nicolas Pitre4adbb6a2016-07-24 11:30:16 -0400538 pr_debug("ROM mapping of file (we hope)\n");
Linus Torvalds1da177e2005-04-16 15:20:36 -0700539
Linus Torvalds6be5ceb2012-04-20 17:13:58 -0700540 textpos = vm_mmap(bprm->file, 0, text_len, PROT_READ|PROT_EXEC,
Matt Helsley925d1c42008-04-29 01:01:36 -0700541 MAP_PRIVATE|MAP_EXECUTABLE, 0);
Mike Frysinger0b8c78f2009-09-23 15:57:07 -0700542 if (!textpos || IS_ERR_VALUE(textpos)) {
Luke Yang1ad3dcc2006-03-25 03:08:24 -0800543 ret = textpos;
Nicolas Pitre13c3f502016-07-24 11:30:15 -0400544 if (!textpos)
545 ret = -ENOMEM;
Nicolas Pitre4adbb6a2016-07-24 11:30:16 -0400546 pr_err("Unable to mmap process text, errno %d\n", ret);
Andrew Mortondf889122006-05-20 15:00:01 -0700547 goto err;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700548 }
549
Greg Ungerer72613e5f2007-02-07 12:03:08 +1000550 len = data_len + extra + MAX_SHARED_LIBS * sizeof(unsigned long);
David Howells0f3e4422009-01-08 12:04:47 +0000551 len = PAGE_ALIGN(len);
Nicolas Pitre13c3f502016-07-24 11:30:15 -0400552 realdatastart = vm_mmap(NULL, 0, len,
Greg Ungerer72613e5f2007-02-07 12:03:08 +1000553 PROT_READ|PROT_WRITE|PROT_EXEC, MAP_PRIVATE, 0);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700554
Mike Frysinger0b8c78f2009-09-23 15:57:07 -0700555 if (realdatastart == 0 || IS_ERR_VALUE(realdatastart)) {
Luke Yang1ad3dcc2006-03-25 03:08:24 -0800556 ret = realdatastart;
Nicolas Pitre13c3f502016-07-24 11:30:15 -0400557 if (!realdatastart)
558 ret = -ENOMEM;
Nicolas Pitre4adbb6a2016-07-24 11:30:16 -0400559 pr_err("Unable to allocate RAM for process data, "
Nicolas Pitre13c3f502016-07-24 11:30:15 -0400560 "errno %d\n", ret);
561 vm_munmap(textpos, text_len);
Andrew Mortondf889122006-05-20 15:00:01 -0700562 goto err;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700563 }
Oskar Schirmerc3dc5be2009-05-28 14:34:31 -0700564 datapos = ALIGN(realdatastart +
565 MAX_SHARED_LIBS * sizeof(unsigned long),
566 FLAT_DATA_ALIGN);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700567
Geert Uytterhoevena8605422017-07-16 13:57:27 +0200568 pr_debug("Allocated data+bss+stack (%u bytes): %lx\n",
Nicolas Pitre4adbb6a2016-07-24 11:30:16 -0400569 data_len + bss_len + stack_len, datapos);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700570
571 fpos = ntohl(hdr->data_start);
572#ifdef CONFIG_BINFMT_ZFLAT
573 if (flags & FLAT_FLAG_GZDATA) {
Nicolas Pitre13c3f502016-07-24 11:30:15 -0400574 result = decompress_exec(bprm, fpos, (char *)datapos,
Al Viro3dc20cb2013-04-13 20:31:37 -0400575 full_data, 0);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700576 } else
577#endif
578 {
Al Viro3dc20cb2013-04-13 20:31:37 -0400579 result = read_code(bprm->file, datapos, fpos,
580 full_data);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700581 }
Mike Frysinger0b8c78f2009-09-23 15:57:07 -0700582 if (IS_ERR_VALUE(result)) {
Nicolas Pitre13c3f502016-07-24 11:30:15 -0400583 ret = result;
Nicolas Pitre4adbb6a2016-07-24 11:30:16 -0400584 pr_err("Unable to read data+bss, errno %d\n", ret);
Al Viro7696e0c32012-05-30 01:56:23 -0400585 vm_munmap(textpos, text_len);
586 vm_munmap(realdatastart, len);
Andrew Mortondf889122006-05-20 15:00:01 -0700587 goto err;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700588 }
589
Al Viro468138d2017-05-02 19:52:17 -0400590 reloc = (u32 __user *)
Nicolas Pitre13c3f502016-07-24 11:30:15 -0400591 (datapos + (ntohl(hdr->reloc_start) - text_len));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700592 memp = realdatastart;
David Howells0f3e4422009-01-08 12:04:47 +0000593 memp_size = len;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700594 } else {
595
Al Viro468138d2017-05-02 19:52:17 -0400596 len = text_len + data_len + extra + MAX_SHARED_LIBS * sizeof(u32);
David Howells0f3e4422009-01-08 12:04:47 +0000597 len = PAGE_ALIGN(len);
Nicolas Pitre13c3f502016-07-24 11:30:15 -0400598 textpos = vm_mmap(NULL, 0, len,
Greg Ungerer72613e5f2007-02-07 12:03:08 +1000599 PROT_READ | PROT_EXEC | PROT_WRITE, MAP_PRIVATE, 0);
Greg Ungerer72613e5f2007-02-07 12:03:08 +1000600
Mike Frysinger0b8c78f2009-09-23 15:57:07 -0700601 if (!textpos || IS_ERR_VALUE(textpos)) {
Luke Yang1ad3dcc2006-03-25 03:08:24 -0800602 ret = textpos;
Nicolas Pitre13c3f502016-07-24 11:30:15 -0400603 if (!textpos)
604 ret = -ENOMEM;
Nicolas Pitre4adbb6a2016-07-24 11:30:16 -0400605 pr_err("Unable to allocate RAM for process text/data, "
Nicolas Pitre13c3f502016-07-24 11:30:15 -0400606 "errno %d\n", ret);
Andrew Mortondf889122006-05-20 15:00:01 -0700607 goto err;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700608 }
609
610 realdatastart = textpos + ntohl(hdr->data_start);
Oskar Schirmerc3dc5be2009-05-28 14:34:31 -0700611 datapos = ALIGN(realdatastart +
Al Viro468138d2017-05-02 19:52:17 -0400612 MAX_SHARED_LIBS * sizeof(u32),
Oskar Schirmerc3dc5be2009-05-28 14:34:31 -0700613 FLAT_DATA_ALIGN);
614
Al Viro468138d2017-05-02 19:52:17 -0400615 reloc = (u32 __user *)
Oskar Schirmerc3dc5be2009-05-28 14:34:31 -0700616 (datapos + (ntohl(hdr->reloc_start) - text_len));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700617 memp = textpos;
David Howells0f3e4422009-01-08 12:04:47 +0000618 memp_size = len;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700619#ifdef CONFIG_BINFMT_ZFLAT
620 /*
621 * load it all in and treat it like a RAM load from now on
622 */
623 if (flags & FLAT_FLAG_GZIP) {
Nicolas Pitre472f95f2016-07-24 11:30:26 -0400624#ifndef CONFIG_MMU
Nicolas Pitre13c3f502016-07-24 11:30:15 -0400625 result = decompress_exec(bprm, sizeof(struct flat_hdr),
626 (((char *)textpos) + sizeof(struct flat_hdr)),
Al Viro3dc20cb2013-04-13 20:31:37 -0400627 (text_len + full_data
Nicolas Pitre13c3f502016-07-24 11:30:15 -0400628 - sizeof(struct flat_hdr)),
Linus Torvalds1da177e2005-04-16 15:20:36 -0700629 0);
630 memmove((void *) datapos, (void *) realdatastart,
Al Viro3dc20cb2013-04-13 20:31:37 -0400631 full_data);
Nicolas Pitre472f95f2016-07-24 11:30:26 -0400632#else
633 /*
634 * This is used on MMU systems mainly for testing.
635 * Let's use a kernel buffer to simplify things.
636 */
637 long unz_text_len = text_len - sizeof(struct flat_hdr);
638 long unz_len = unz_text_len + full_data;
639 char *unz_data = vmalloc(unz_len);
640 if (!unz_data) {
641 result = -ENOMEM;
642 } else {
643 result = decompress_exec(bprm, sizeof(struct flat_hdr),
644 unz_data, unz_len, 0);
645 if (result == 0 &&
646 (copy_to_user((void __user *)textpos + sizeof(struct flat_hdr),
647 unz_data, unz_text_len) ||
648 copy_to_user((void __user *)datapos,
649 unz_data + unz_text_len, full_data)))
650 result = -EFAULT;
651 vfree(unz_data);
652 }
653#endif
Linus Torvalds1da177e2005-04-16 15:20:36 -0700654 } else if (flags & FLAT_FLAG_GZDATA) {
Al Viro3dc20cb2013-04-13 20:31:37 -0400655 result = read_code(bprm->file, textpos, 0, text_len);
Nicolas Pitre472f95f2016-07-24 11:30:26 -0400656 if (!IS_ERR_VALUE(result)) {
657#ifndef CONFIG_MMU
Linus Torvalds1da177e2005-04-16 15:20:36 -0700658 result = decompress_exec(bprm, text_len, (char *) datapos,
Al Viro3dc20cb2013-04-13 20:31:37 -0400659 full_data, 0);
Nicolas Pitre472f95f2016-07-24 11:30:26 -0400660#else
661 char *unz_data = vmalloc(full_data);
662 if (!unz_data) {
663 result = -ENOMEM;
664 } else {
665 result = decompress_exec(bprm, text_len,
666 unz_data, full_data, 0);
667 if (result == 0 &&
668 copy_to_user((void __user *)datapos,
669 unz_data, full_data))
670 result = -EFAULT;
671 vfree(unz_data);
672 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700673#endif
Nicolas Pitre472f95f2016-07-24 11:30:26 -0400674 }
675 } else
676#endif /* CONFIG_BINFMT_ZFLAT */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700677 {
Al Viro3dc20cb2013-04-13 20:31:37 -0400678 result = read_code(bprm->file, textpos, 0, text_len);
679 if (!IS_ERR_VALUE(result))
680 result = read_code(bprm->file, datapos,
681 ntohl(hdr->data_start),
682 full_data);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700683 }
Mike Frysinger0b8c78f2009-09-23 15:57:07 -0700684 if (IS_ERR_VALUE(result)) {
Nicolas Pitre13c3f502016-07-24 11:30:15 -0400685 ret = result;
Nicolas Pitre4adbb6a2016-07-24 11:30:16 -0400686 pr_err("Unable to read code+data+bss, errno %d\n", ret);
Al Viro7696e0c32012-05-30 01:56:23 -0400687 vm_munmap(textpos, text_len + data_len + extra +
Al Viro468138d2017-05-02 19:52:17 -0400688 MAX_SHARED_LIBS * sizeof(u32));
Andrew Mortondf889122006-05-20 15:00:01 -0700689 goto err;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700690 }
691 }
692
Nicolas Pitre13c3f502016-07-24 11:30:15 -0400693 start_code = textpos + sizeof(struct flat_hdr);
694 end_code = textpos + text_len;
695 text_len -= sizeof(struct flat_hdr); /* the real code len */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700696
697 /* The main program needs a little extra setup in the task structure */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700698 if (id == 0) {
699 current->mm->start_code = start_code;
700 current->mm->end_code = end_code;
701 current->mm->start_data = datapos;
702 current->mm->end_data = datapos + data_len;
703 /*
704 * set up the brk stuff, uses any slack left in data/bss/stack
705 * allocation. We put the brk after the bss (between the bss
706 * and stack) like other platforms.
David Howells0f3e4422009-01-08 12:04:47 +0000707 * Userspace code relies on the stack pointer starting out at
708 * an address right at the end of a page.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700709 */
710 current->mm->start_brk = datapos + data_len + bss_len;
711 current->mm->brk = (current->mm->start_brk + 3) & ~3;
Nicolas Pitre015feac2016-07-24 11:30:25 -0400712#ifndef CONFIG_MMU
David Howells0f3e4422009-01-08 12:04:47 +0000713 current->mm->context.end_brk = memp + memp_size - stack_len;
Nicolas Pitre015feac2016-07-24 11:30:25 -0400714#endif
Linus Torvalds1da177e2005-04-16 15:20:36 -0700715 }
716
Nicolas Pitre13c3f502016-07-24 11:30:15 -0400717 if (flags & FLAT_FLAG_KTRACE) {
Nicolas Pitre4adbb6a2016-07-24 11:30:16 -0400718 pr_info("Mapping is %lx, Entry point is %x, data_start is %x\n",
719 textpos, 0x00ffffff&ntohl(hdr->entry), ntohl(hdr->data_start));
720 pr_info("%s %s: TEXT=%lx-%lx DATA=%lx-%lx BSS=%lx-%lx\n",
721 id ? "Lib" : "Load", bprm->filename,
722 start_code, end_code, datapos, datapos + data_len,
723 datapos + data_len, (datapos + data_len + bss_len + 3) & ~3);
Nicolas Pitre13c3f502016-07-24 11:30:15 -0400724 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700725
726 /* Store the current module values into the global library structure */
727 libinfo->lib_list[id].start_code = start_code;
728 libinfo->lib_list[id].start_data = datapos;
729 libinfo->lib_list[id].start_brk = datapos + data_len + bss_len;
730 libinfo->lib_list[id].text_len = text_len;
731 libinfo->lib_list[id].loaded = 1;
732 libinfo->lib_list[id].entry = (0x00ffffff & ntohl(hdr->entry)) + textpos;
733 libinfo->lib_list[id].build_date = ntohl(hdr->build_date);
Nicolas Pitre13c3f502016-07-24 11:30:15 -0400734
Linus Torvalds1da177e2005-04-16 15:20:36 -0700735 /*
736 * We just load the allocations into some temporary memory to
737 * help simplify all this mumbo jumbo
738 *
739 * We've got two different sections of relocation entries.
Lucas De Marchi25985ed2011-03-30 22:57:33 -0300740 * The first is the GOT which resides at the beginning of the data segment
Linus Torvalds1da177e2005-04-16 15:20:36 -0700741 * and is terminated with a -1. This one can be relocated in place.
742 * The second is the extra relocation entries tacked after the image's
743 * data segment. These require a little more processing as the entry is
744 * really an offset into the image which contains an offset into the
745 * image.
746 */
747 if (flags & FLAT_FLAG_GOTPIC) {
Al Viro468138d2017-05-02 19:52:17 -0400748 for (rp = (u32 __user *)datapos; ; rp++) {
749 u32 addr, rp_val;
Nicolas Pitre6e572ff2016-07-24 11:30:21 -0400750 if (get_user(rp_val, rp))
751 return -EFAULT;
752 if (rp_val == 0xffffffff)
753 break;
754 if (rp_val) {
755 addr = calc_reloc(rp_val, libinfo, id, 0);
Luke Yang1ad3dcc2006-03-25 03:08:24 -0800756 if (addr == RELOC_FAILED) {
757 ret = -ENOEXEC;
Andrew Mortondf889122006-05-20 15:00:01 -0700758 goto err;
Luke Yang1ad3dcc2006-03-25 03:08:24 -0800759 }
Nicolas Pitre6e572ff2016-07-24 11:30:21 -0400760 if (put_user(addr, rp))
761 return -EFAULT;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700762 }
763 }
764 }
765
766 /*
767 * Now run through the relocation entries.
768 * We've got to be careful here as C++ produces relocatable zero
769 * entries in the constructor and destructor tables which are then
770 * tested for being not zero (which will always occur unless we're
771 * based from address zero). This causes an endless loop as __start
772 * is at zero. The solution used is to not relocate zero addresses.
773 * This has the negative side effect of not allowing a global data
774 * reference to be statically initialised to _stext (I've moved
775 * __start to address 4 so that is okay).
776 */
777 if (rev > OLD_FLAT_VERSION) {
Al Viro468138d2017-05-02 19:52:17 -0400778 u32 __maybe_unused persistent = 0;
Nicolas Pitre13c3f502016-07-24 11:30:15 -0400779 for (i = 0; i < relocs; i++) {
Al Viro468138d2017-05-02 19:52:17 -0400780 u32 addr, relval;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700781
Nicolas Pitre13c3f502016-07-24 11:30:15 -0400782 /*
783 * Get the address of the pointer to be
784 * relocated (of course, the address has to be
785 * relocated first).
786 */
Nicolas Pitre6e572ff2016-07-24 11:30:21 -0400787 if (get_user(relval, reloc + i))
788 return -EFAULT;
789 relval = ntohl(relval);
Nicolas Pitre13c3f502016-07-24 11:30:15 -0400790 if (flat_set_persistent(relval, &persistent))
Bernd Schmidtf9720202007-10-03 23:41:43 +0800791 continue;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700792 addr = flat_get_relocate_addr(relval);
Al Viro468138d2017-05-02 19:52:17 -0400793 rp = (u32 __user *)calc_reloc(addr, libinfo, id, 1);
794 if (rp == (u32 __user *)RELOC_FAILED) {
Luke Yang1ad3dcc2006-03-25 03:08:24 -0800795 ret = -ENOEXEC;
Andrew Mortondf889122006-05-20 15:00:01 -0700796 goto err;
Luke Yang1ad3dcc2006-03-25 03:08:24 -0800797 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700798
799 /* Get the pointer's value. */
Al Viro468138d2017-05-02 19:52:17 -0400800 ret = flat_get_addr_from_rp(rp, relval, flags,
801 &addr, &persistent);
802 if (unlikely(ret))
803 goto err;
804
Linus Torvalds1da177e2005-04-16 15:20:36 -0700805 if (addr != 0) {
806 /*
807 * Do the relocation. PIC relocs in the data section are
808 * already in target order
809 */
810 if ((flags & FLAT_FLAG_GOTPIC) == 0)
811 addr = ntohl(addr);
812 addr = calc_reloc(addr, libinfo, id, 0);
Luke Yang1ad3dcc2006-03-25 03:08:24 -0800813 if (addr == RELOC_FAILED) {
814 ret = -ENOEXEC;
Andrew Mortondf889122006-05-20 15:00:01 -0700815 goto err;
Luke Yang1ad3dcc2006-03-25 03:08:24 -0800816 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700817
818 /* Write back the relocated pointer. */
Al Viro468138d2017-05-02 19:52:17 -0400819 ret = flat_put_addr_at_rp(rp, addr, relval);
820 if (unlikely(ret))
821 goto err;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700822 }
823 }
824 } else {
Nicolas Pitre1b2ce442016-07-24 11:30:22 -0400825 for (i = 0; i < relocs; i++) {
Al Viro468138d2017-05-02 19:52:17 -0400826 u32 relval;
Nicolas Pitre1b2ce442016-07-24 11:30:22 -0400827 if (get_user(relval, reloc + i))
828 return -EFAULT;
829 relval = ntohl(relval);
830 old_reloc(relval);
831 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700832 }
Nicolas Pitre13c3f502016-07-24 11:30:15 -0400833
Linus Torvalds1da177e2005-04-16 15:20:36 -0700834 flush_icache_range(start_code, end_code);
835
836 /* zero the BSS, BRK and stack areas */
Nicolas Pitre467aa142016-07-24 11:30:23 -0400837 if (clear_user((void __user *)(datapos + data_len), bss_len +
838 (memp + memp_size - stack_len - /* end brk */
839 libinfo->lib_list[id].start_brk) + /* start brk */
840 stack_len))
841 return -EFAULT;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700842
843 return 0;
Luke Yang1ad3dcc2006-03-25 03:08:24 -0800844err:
845 return ret;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700846}
847
848
849/****************************************************************************/
850#ifdef CONFIG_BINFMT_SHARED_FLAT
851
852/*
853 * Load a shared library into memory. The library gets its own data
854 * segment (including bss) but not argv/argc/environ.
855 */
856
857static int load_flat_shared_library(int id, struct lib_info *libs)
858{
859 struct linux_binprm bprm;
860 int res;
861 char buf[16];
862
David Howells3a852d32011-04-28 16:26:38 +0100863 memset(&bprm, 0, sizeof(bprm));
864
Linus Torvalds1da177e2005-04-16 15:20:36 -0700865 /* Create the file name */
866 sprintf(buf, "/lib/lib%d.so", id);
867
868 /* Open the file up */
869 bprm.filename = buf;
870 bprm.file = open_exec(bprm.filename);
871 res = PTR_ERR(bprm.file);
872 if (IS_ERR(bprm.file))
873 return res;
874
Linus Torvalds34406252009-08-06 15:09:34 -0700875 bprm.cred = prepare_exec_creds();
876 res = -ENOMEM;
877 if (!bprm.cred)
878 goto out;
879
David Howells3a852d32011-04-28 16:26:38 +0100880 /* We don't really care about recalculating credentials at this point
881 * as we're past the point of no return and are dealing with shared
882 * libraries.
883 */
Kees Cookddb4a142017-07-18 15:25:23 -0700884 bprm.called_set_creds = 1;
David Howells3a852d32011-04-28 16:26:38 +0100885
Linus Torvalds1da177e2005-04-16 15:20:36 -0700886 res = prepare_binprm(&bprm);
887
Arnd Bergmann287980e2016-05-27 23:23:25 +0200888 if (!res)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700889 res = load_flat_file(&bprm, libs, id, NULL);
Linus Torvalds34406252009-08-06 15:09:34 -0700890
891 abort_creds(bprm.cred);
892
893out:
894 allow_write_access(bprm.file);
895 fput(bprm.file);
896
Nicolas Pitre13c3f502016-07-24 11:30:15 -0400897 return res;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700898}
899
900#endif /* CONFIG_BINFMT_SHARED_FLAT */
901/****************************************************************************/
902
903/*
904 * These are the functions used to load flat style executables and shared
905 * libraries. There is no binary dependent code anywhere else.
906 */
907
Nicolas Pitre13c3f502016-07-24 11:30:15 -0400908static int load_flat_binary(struct linux_binprm *bprm)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700909{
910 struct lib_info libinfo;
Al Viro71613c32012-10-20 22:00:48 -0400911 struct pt_regs *regs = current_pt_regs();
Nicolas Pitre015feac2016-07-24 11:30:25 -0400912 unsigned long stack_len = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700913 unsigned long start_addr;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700914 int res;
915 int i, j;
916
917 memset(&libinfo, 0, sizeof(libinfo));
Nicolas Pitre13c3f502016-07-24 11:30:15 -0400918
Linus Torvalds1da177e2005-04-16 15:20:36 -0700919 /*
920 * We have to add the size of our arguments to our stack size
921 * otherwise it's too easy for users to create stack overflows
922 * by passing in a huge argument list. And yes, we have to be
923 * pedantic and include space for the argv/envp array as it may have
924 * a lot of entries.
925 */
Nicolas Pitre015feac2016-07-24 11:30:25 -0400926#ifndef CONFIG_MMU
927 stack_len += PAGE_SIZE * MAX_ARG_PAGES - bprm->p; /* the strings */
928#endif
Nicolas Pitrea97d1572016-07-24 11:30:20 -0400929 stack_len += (bprm->argc + 1) * sizeof(char *); /* the argv array */
930 stack_len += (bprm->envc + 1) * sizeof(char *); /* the envp array */
931 stack_len = ALIGN(stack_len, FLAT_STACK_ALIGN);
Nicolas Pitre13c3f502016-07-24 11:30:15 -0400932
Linus Torvalds1da177e2005-04-16 15:20:36 -0700933 res = load_flat_file(bprm, &libinfo, 0, &stack_len);
Arnd Bergmann287980e2016-05-27 23:23:25 +0200934 if (res < 0)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700935 return res;
Nicolas Pitre13c3f502016-07-24 11:30:15 -0400936
Linus Torvalds1da177e2005-04-16 15:20:36 -0700937 /* Update data segment pointers for all libraries */
Nicolas Pitreaf521f92016-07-24 11:30:24 -0400938 for (i = 0; i < MAX_SHARED_LIBS; i++) {
939 if (!libinfo.lib_list[i].loaded)
940 continue;
941 for (j = 0; j < MAX_SHARED_LIBS; j++) {
942 unsigned long val = libinfo.lib_list[j].loaded ?
943 libinfo.lib_list[j].start_data : UNLOADED_LIB;
944 unsigned long __user *p = (unsigned long __user *)
945 libinfo.lib_list[i].start_data;
946 p -= j + 1;
947 if (put_user(val, p))
948 return -EFAULT;
949 }
950 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700951
David Howellsa6f76f22008-11-14 10:39:24 +1100952 install_exec_creds(bprm);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700953
954 set_binfmt(&flat_format);
955
Nicolas Pitre015feac2016-07-24 11:30:25 -0400956#ifdef CONFIG_MMU
957 res = setup_arg_pages(bprm, STACK_TOP, EXSTACK_DEFAULT);
958 if (!res)
959 res = create_flat_tables(bprm, bprm->p);
960#else
Nicolas Pitrea97d1572016-07-24 11:30:20 -0400961 /* Stash our initial stack pointer into the mm structure */
962 current->mm->start_stack =
963 ((current->mm->context.end_brk + stack_len + 3) & ~3) - 4;
964 pr_debug("sp=%lx\n", current->mm->start_stack);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700965
Nicolas Pitre687fd772016-07-24 11:30:19 -0400966 /* copy the arg pages onto the stack */
Nicolas Pitrea97d1572016-07-24 11:30:20 -0400967 res = transfer_args_to_stack(bprm, &current->mm->start_stack);
968 if (!res)
969 res = create_flat_tables(bprm, current->mm->start_stack);
Nicolas Pitre015feac2016-07-24 11:30:25 -0400970#endif
Nicolas Pitre687fd772016-07-24 11:30:19 -0400971 if (res)
972 return res;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700973
Linus Torvalds1da177e2005-04-16 15:20:36 -0700974 /* Fake some return addresses to ensure the call chain will
975 * initialise library in order for us. We are required to call
976 * lib 1 first, then 2, ... and finally the main program (id 0).
977 */
978 start_addr = libinfo.lib_list[0].entry;
979
980#ifdef CONFIG_BINFMT_SHARED_FLAT
Nicolas Pitre13c3f502016-07-24 11:30:15 -0400981 for (i = MAX_SHARED_LIBS-1; i > 0; i--) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700982 if (libinfo.lib_list[i].loaded) {
983 /* Push previos first to call address */
Nicolas Pitrea97d1572016-07-24 11:30:20 -0400984 unsigned long __user *sp;
985 current->mm->start_stack -= sizeof(unsigned long);
986 sp = (unsigned long __user *)current->mm->start_stack;
987 __put_user(start_addr, sp);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700988 start_addr = libinfo.lib_list[i].entry;
989 }
990 }
991#endif
Nicolas Pitre13c3f502016-07-24 11:30:15 -0400992
Takashi YOSHII74c27c42008-08-11 20:10:54 +0900993#ifdef FLAT_PLAT_INIT
994 FLAT_PLAT_INIT(regs);
995#endif
Nicolas Pitre13c3f502016-07-24 11:30:15 -0400996
Nicolas Pitre4adbb6a2016-07-24 11:30:16 -0400997 pr_debug("start_thread(regs=0x%p, entry=0x%lx, start_stack=0x%lx)\n",
998 regs, start_addr, current->mm->start_stack);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700999 start_thread(regs, start_addr, current->mm->start_stack);
1000
Linus Torvalds1da177e2005-04-16 15:20:36 -07001001 return 0;
1002}
1003
1004/****************************************************************************/
1005
1006static int __init init_flat_binfmt(void)
1007{
Al Viro8fc3dc52012-03-17 03:05:16 -04001008 register_binfmt(&flat_format);
1009 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001010}
Linus Torvalds1da177e2005-04-16 15:20:36 -07001011core_initcall(init_flat_binfmt);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001012
1013/****************************************************************************/