blob: 7c1e65d54872bfea6611743a8ea7636c9dca2949 [file] [log] [blame]
Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
2 * linux/fs/binfmt_elf.c
3 *
4 * These are the functions used to load ELF format executables as used
5 * on SVr4 machines. Information on the format may be found in the book
6 * "UNIX SYSTEM V RELEASE 4 Programmers Guide: Ansi C and Programming Support
7 * Tools".
8 *
9 * Copyright 1993, 1994: Eric Youngdale (ericy@cais.com).
10 */
11
12#include <linux/module.h>
13#include <linux/kernel.h>
14#include <linux/fs.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070015#include <linux/mm.h>
16#include <linux/mman.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070017#include <linux/errno.h>
18#include <linux/signal.h>
19#include <linux/binfmts.h>
20#include <linux/string.h>
21#include <linux/file.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070022#include <linux/slab.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070023#include <linux/personality.h>
24#include <linux/elfcore.h>
25#include <linux/init.h>
26#include <linux/highuid.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070027#include <linux/compiler.h>
28#include <linux/highmem.h>
29#include <linux/pagemap.h>
30#include <linux/security.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070031#include <linux/random.h>
Jesper Juhlf4e5cc22006-06-23 02:05:35 -070032#include <linux/elf.h>
Alexey Dobriyan7e80d0d2007-05-08 00:28:59 -070033#include <linux/utsname.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070034#include <asm/uaccess.h>
35#include <asm/param.h>
36#include <asm/page.h>
37
Jesper Juhlf4e5cc22006-06-23 02:05:35 -070038static int load_elf_binary(struct linux_binprm *bprm, struct pt_regs *regs);
39static int load_elf_library(struct file *);
Andrew Mortonbb1ad822008-01-30 13:31:07 +010040static unsigned long elf_map(struct file *, unsigned long, struct elf_phdr *,
41 int, int, unsigned long);
Linus Torvalds1da177e2005-04-16 15:20:36 -070042
Linus Torvalds1da177e2005-04-16 15:20:36 -070043/*
44 * If we don't support core dumping, then supply a NULL so we
45 * don't even try.
46 */
Matt Mackall708e9a72006-01-08 01:05:25 -080047#if defined(USE_ELF_CORE_DUMP) && defined(CONFIG_ELF_CORE)
Neil Horman7dc0b222007-10-16 23:26:34 -070048static int elf_core_dump(long signr, struct pt_regs *regs, struct file *file, unsigned long limit);
Linus Torvalds1da177e2005-04-16 15:20:36 -070049#else
50#define elf_core_dump NULL
51#endif
52
53#if ELF_EXEC_PAGESIZE > PAGE_SIZE
Jesper Juhlf4e5cc22006-06-23 02:05:35 -070054#define ELF_MIN_ALIGN ELF_EXEC_PAGESIZE
Linus Torvalds1da177e2005-04-16 15:20:36 -070055#else
Jesper Juhlf4e5cc22006-06-23 02:05:35 -070056#define ELF_MIN_ALIGN PAGE_SIZE
Linus Torvalds1da177e2005-04-16 15:20:36 -070057#endif
58
59#ifndef ELF_CORE_EFLAGS
60#define ELF_CORE_EFLAGS 0
61#endif
62
63#define ELF_PAGESTART(_v) ((_v) & ~(unsigned long)(ELF_MIN_ALIGN-1))
64#define ELF_PAGEOFFSET(_v) ((_v) & (ELF_MIN_ALIGN-1))
65#define ELF_PAGEALIGN(_v) (((_v) + ELF_MIN_ALIGN - 1) & ~(ELF_MIN_ALIGN - 1))
66
67static struct linux_binfmt elf_format = {
68 .module = THIS_MODULE,
69 .load_binary = load_elf_binary,
70 .load_shlib = load_elf_library,
71 .core_dump = elf_core_dump,
Andi Kleen9fbbd4d2007-02-13 13:26:26 +010072 .min_coredump = ELF_EXEC_PAGESIZE,
73 .hasvdso = 1
Linus Torvalds1da177e2005-04-16 15:20:36 -070074};
75
Andrew Mortond4e3cc32007-07-21 04:37:32 -070076#define BAD_ADDR(x) ((unsigned long)(x) >= TASK_SIZE)
Linus Torvalds1da177e2005-04-16 15:20:36 -070077
78static int set_brk(unsigned long start, unsigned long end)
79{
80 start = ELF_PAGEALIGN(start);
81 end = ELF_PAGEALIGN(end);
82 if (end > start) {
83 unsigned long addr;
84 down_write(&current->mm->mmap_sem);
85 addr = do_brk(start, end - start);
86 up_write(&current->mm->mmap_sem);
87 if (BAD_ADDR(addr))
88 return addr;
89 }
90 current->mm->start_brk = current->mm->brk = end;
91 return 0;
92}
93
Linus Torvalds1da177e2005-04-16 15:20:36 -070094/* We need to explicitly zero any fractional pages
95 after the data section (i.e. bss). This would
96 contain the junk from the file that should not
Jesper Juhlf4e5cc22006-06-23 02:05:35 -070097 be in memory
98 */
Linus Torvalds1da177e2005-04-16 15:20:36 -070099static int padzero(unsigned long elf_bss)
100{
101 unsigned long nbyte;
102
103 nbyte = ELF_PAGEOFFSET(elf_bss);
104 if (nbyte) {
105 nbyte = ELF_MIN_ALIGN - nbyte;
106 if (clear_user((void __user *) elf_bss, nbyte))
107 return -EFAULT;
108 }
109 return 0;
110}
111
Ohad Ben-Cohen09c6dd32008-02-03 18:05:15 +0200112/* Let's use some macros to make this stack manipulation a little clearer */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700113#ifdef CONFIG_STACK_GROWSUP
114#define STACK_ADD(sp, items) ((elf_addr_t __user *)(sp) + (items))
115#define STACK_ROUND(sp, items) \
116 ((15 + (unsigned long) ((sp) + (items))) &~ 15UL)
Jesper Juhlf4e5cc22006-06-23 02:05:35 -0700117#define STACK_ALLOC(sp, len) ({ \
118 elf_addr_t __user *old_sp = (elf_addr_t __user *)sp; sp += len; \
119 old_sp; })
Linus Torvalds1da177e2005-04-16 15:20:36 -0700120#else
121#define STACK_ADD(sp, items) ((elf_addr_t __user *)(sp) - (items))
122#define STACK_ROUND(sp, items) \
123 (((unsigned long) (sp - items)) &~ 15UL)
124#define STACK_ALLOC(sp, len) ({ sp -= len ; sp; })
125#endif
126
Nathan Lynch483fad12008-07-22 04:48:46 +1000127#ifndef ELF_BASE_PLATFORM
128/*
129 * AT_BASE_PLATFORM indicates the "real" hardware/microarchitecture.
130 * If the arch defines ELF_BASE_PLATFORM (in asm/elf.h), the value
131 * will be copied to the user stack in the same manner as AT_PLATFORM.
132 */
133#define ELF_BASE_PLATFORM NULL
134#endif
135
Linus Torvalds1da177e2005-04-16 15:20:36 -0700136static int
Jesper Juhlf4e5cc22006-06-23 02:05:35 -0700137create_elf_tables(struct linux_binprm *bprm, struct elfhdr *exec,
Andi Kleend20894a2008-02-08 04:21:54 -0800138 unsigned long load_addr, unsigned long interp_load_addr)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700139{
140 unsigned long p = bprm->p;
141 int argc = bprm->argc;
142 int envc = bprm->envc;
143 elf_addr_t __user *argv;
144 elf_addr_t __user *envp;
145 elf_addr_t __user *sp;
146 elf_addr_t __user *u_platform;
Nathan Lynch483fad12008-07-22 04:48:46 +1000147 elf_addr_t __user *u_base_platform;
Kees Cookf06295b2009-01-07 18:08:52 -0800148 elf_addr_t __user *u_rand_bytes;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700149 const char *k_platform = ELF_PLATFORM;
Nathan Lynch483fad12008-07-22 04:48:46 +1000150 const char *k_base_platform = ELF_BASE_PLATFORM;
Kees Cookf06295b2009-01-07 18:08:52 -0800151 unsigned char k_rand_bytes[16];
Linus Torvalds1da177e2005-04-16 15:20:36 -0700152 int items;
153 elf_addr_t *elf_info;
154 int ei_index = 0;
David Howells86a264a2008-11-14 10:39:18 +1100155 const struct cred *cred = current_cred();
Ollie Wildb6a2fea2007-07-19 01:48:16 -0700156 struct vm_area_struct *vma;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700157
158 /*
Franck Bui-Huud68c9d62007-10-16 23:30:24 -0700159 * In some cases (e.g. Hyper-Threading), we want to avoid L1
160 * evictions by the processes running on the same package. One
161 * thing we can do is to shuffle the initial stack for them.
162 */
163
164 p = arch_align_stack(p);
165
166 /*
Linus Torvalds1da177e2005-04-16 15:20:36 -0700167 * If this architecture has a platform capability string, copy it
168 * to userspace. In some cases (Sparc), this info is impossible
169 * for userspace to get any other way, in others (i386) it is
170 * merely difficult.
171 */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700172 u_platform = NULL;
173 if (k_platform) {
174 size_t len = strlen(k_platform) + 1;
175
Linus Torvalds1da177e2005-04-16 15:20:36 -0700176 u_platform = (elf_addr_t __user *)STACK_ALLOC(p, len);
177 if (__copy_to_user(u_platform, k_platform, len))
178 return -EFAULT;
179 }
180
Nathan Lynch483fad12008-07-22 04:48:46 +1000181 /*
182 * If this architecture has a "base" platform capability
183 * string, copy it to userspace.
184 */
185 u_base_platform = NULL;
186 if (k_base_platform) {
187 size_t len = strlen(k_base_platform) + 1;
188
189 u_base_platform = (elf_addr_t __user *)STACK_ALLOC(p, len);
190 if (__copy_to_user(u_base_platform, k_base_platform, len))
191 return -EFAULT;
192 }
193
Kees Cookf06295b2009-01-07 18:08:52 -0800194 /*
195 * Generate 16 random bytes for userspace PRNG seeding.
196 */
197 get_random_bytes(k_rand_bytes, sizeof(k_rand_bytes));
198 u_rand_bytes = (elf_addr_t __user *)
199 STACK_ALLOC(p, sizeof(k_rand_bytes));
200 if (__copy_to_user(u_rand_bytes, k_rand_bytes, sizeof(k_rand_bytes)))
201 return -EFAULT;
202
Linus Torvalds1da177e2005-04-16 15:20:36 -0700203 /* Create the ELF interpreter info */
Jesper Juhl785d5572006-06-23 02:05:35 -0700204 elf_info = (elf_addr_t *)current->mm->saved_auxv;
Olaf Hering4f9a58d2007-10-16 23:30:12 -0700205 /* update AT_VECTOR_SIZE_BASE if the number of NEW_AUX_ENT() changes */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700206#define NEW_AUX_ENT(id, val) \
Jesper Juhlf4e5cc22006-06-23 02:05:35 -0700207 do { \
Jesper Juhl785d5572006-06-23 02:05:35 -0700208 elf_info[ei_index++] = id; \
209 elf_info[ei_index++] = val; \
Jesper Juhlf4e5cc22006-06-23 02:05:35 -0700210 } while (0)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700211
212#ifdef ARCH_DLINFO
213 /*
214 * ARCH_DLINFO must come first so PPC can do its special alignment of
215 * AUXV.
Olaf Hering4f9a58d2007-10-16 23:30:12 -0700216 * update AT_VECTOR_SIZE_ARCH if the number of NEW_AUX_ENT() in
217 * ARCH_DLINFO changes
Linus Torvalds1da177e2005-04-16 15:20:36 -0700218 */
219 ARCH_DLINFO;
220#endif
221 NEW_AUX_ENT(AT_HWCAP, ELF_HWCAP);
222 NEW_AUX_ENT(AT_PAGESZ, ELF_EXEC_PAGESIZE);
223 NEW_AUX_ENT(AT_CLKTCK, CLOCKS_PER_SEC);
224 NEW_AUX_ENT(AT_PHDR, load_addr + exec->e_phoff);
Jesper Juhlf4e5cc22006-06-23 02:05:35 -0700225 NEW_AUX_ENT(AT_PHENT, sizeof(struct elf_phdr));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700226 NEW_AUX_ENT(AT_PHNUM, exec->e_phnum);
227 NEW_AUX_ENT(AT_BASE, interp_load_addr);
228 NEW_AUX_ENT(AT_FLAGS, 0);
229 NEW_AUX_ENT(AT_ENTRY, exec->e_entry);
David Howells86a264a2008-11-14 10:39:18 +1100230 NEW_AUX_ENT(AT_UID, cred->uid);
231 NEW_AUX_ENT(AT_EUID, cred->euid);
232 NEW_AUX_ENT(AT_GID, cred->gid);
233 NEW_AUX_ENT(AT_EGID, cred->egid);
Jesper Juhl785d5572006-06-23 02:05:35 -0700234 NEW_AUX_ENT(AT_SECURE, security_bprm_secureexec(bprm));
Kees Cookf06295b2009-01-07 18:08:52 -0800235 NEW_AUX_ENT(AT_RANDOM, (elf_addr_t)(unsigned long)u_rand_bytes);
John Reiser65191082008-07-21 14:21:32 -0700236 NEW_AUX_ENT(AT_EXECFN, bprm->exec);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700237 if (k_platform) {
Jesper Juhlf4e5cc22006-06-23 02:05:35 -0700238 NEW_AUX_ENT(AT_PLATFORM,
Jesper Juhl785d5572006-06-23 02:05:35 -0700239 (elf_addr_t)(unsigned long)u_platform);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700240 }
Nathan Lynch483fad12008-07-22 04:48:46 +1000241 if (k_base_platform) {
242 NEW_AUX_ENT(AT_BASE_PLATFORM,
243 (elf_addr_t)(unsigned long)u_base_platform);
244 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700245 if (bprm->interp_flags & BINPRM_FLAGS_EXECFD) {
Jesper Juhl785d5572006-06-23 02:05:35 -0700246 NEW_AUX_ENT(AT_EXECFD, bprm->interp_data);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700247 }
248#undef NEW_AUX_ENT
249 /* AT_NULL is zero; clear the rest too */
250 memset(&elf_info[ei_index], 0,
251 sizeof current->mm->saved_auxv - ei_index * sizeof elf_info[0]);
252
253 /* And advance past the AT_NULL entry. */
254 ei_index += 2;
255
256 sp = STACK_ADD(p, ei_index);
257
Andi Kleend20894a2008-02-08 04:21:54 -0800258 items = (argc + 1) + (envc + 1) + 1;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700259 bprm->p = STACK_ROUND(sp, items);
260
261 /* Point sp at the lowest address on the stack */
262#ifdef CONFIG_STACK_GROWSUP
263 sp = (elf_addr_t __user *)bprm->p - items - ei_index;
Jesper Juhlf4e5cc22006-06-23 02:05:35 -0700264 bprm->exec = (unsigned long)sp; /* XXX: PARISC HACK */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700265#else
266 sp = (elf_addr_t __user *)bprm->p;
267#endif
268
Ollie Wildb6a2fea2007-07-19 01:48:16 -0700269
270 /*
271 * Grow the stack manually; some architectures have a limit on how
272 * far ahead a user-space access may be in order to grow the stack.
273 */
274 vma = find_extend_vma(current->mm, bprm->p);
275 if (!vma)
276 return -EFAULT;
277
Linus Torvalds1da177e2005-04-16 15:20:36 -0700278 /* Now, let's put argc (and argv, envp if appropriate) on the stack */
279 if (__put_user(argc, sp++))
280 return -EFAULT;
Andi Kleend20894a2008-02-08 04:21:54 -0800281 argv = sp;
282 envp = argv + argc + 1;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700283
284 /* Populate argv and envp */
Greg Kroah-Hartmana84a5052005-05-11 00:10:44 -0700285 p = current->mm->arg_end = current->mm->arg_start;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700286 while (argc-- > 0) {
287 size_t len;
Heiko Carstens841d5fb2006-12-06 20:36:35 -0800288 if (__put_user((elf_addr_t)p, argv++))
289 return -EFAULT;
Ollie Wildb6a2fea2007-07-19 01:48:16 -0700290 len = strnlen_user((void __user *)p, MAX_ARG_STRLEN);
291 if (!len || len > MAX_ARG_STRLEN)
WANG Cong23c49712008-05-08 21:52:33 +0800292 return -EINVAL;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700293 p += len;
294 }
295 if (__put_user(0, argv))
296 return -EFAULT;
297 current->mm->arg_end = current->mm->env_start = p;
298 while (envc-- > 0) {
299 size_t len;
Heiko Carstens841d5fb2006-12-06 20:36:35 -0800300 if (__put_user((elf_addr_t)p, envp++))
301 return -EFAULT;
Ollie Wildb6a2fea2007-07-19 01:48:16 -0700302 len = strnlen_user((void __user *)p, MAX_ARG_STRLEN);
303 if (!len || len > MAX_ARG_STRLEN)
WANG Cong23c49712008-05-08 21:52:33 +0800304 return -EINVAL;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700305 p += len;
306 }
307 if (__put_user(0, envp))
308 return -EFAULT;
309 current->mm->env_end = p;
310
311 /* Put the elf_info on the stack in the right place. */
312 sp = (elf_addr_t __user *)envp + 1;
313 if (copy_to_user(sp, elf_info, ei_index * sizeof(elf_addr_t)))
314 return -EFAULT;
315 return 0;
316}
317
318#ifndef elf_map
319
320static unsigned long elf_map(struct file *filep, unsigned long addr,
Jiri Kosinacc503c12008-01-30 13:31:07 +0100321 struct elf_phdr *eppnt, int prot, int type,
322 unsigned long total_size)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700323{
324 unsigned long map_addr;
Jiri Kosinacc503c12008-01-30 13:31:07 +0100325 unsigned long size = eppnt->p_filesz + ELF_PAGEOFFSET(eppnt->p_vaddr);
326 unsigned long off = eppnt->p_offset - ELF_PAGEOFFSET(eppnt->p_vaddr);
327 addr = ELF_PAGESTART(addr);
328 size = ELF_PAGEALIGN(size);
Jan Kratochvil60bfba72007-07-15 23:40:06 -0700329
Andrew Mortond4e3cc32007-07-21 04:37:32 -0700330 /* mmap() will return -EINVAL if given a zero size, but a
331 * segment with zero filesize is perfectly valid */
Jiri Kosinacc503c12008-01-30 13:31:07 +0100332 if (!size)
333 return addr;
334
335 down_write(&current->mm->mmap_sem);
336 /*
337 * total_size is the size of the ELF (interpreter) image.
338 * The _first_ mmap needs to know the full size, otherwise
339 * randomization might put this image into an overlapping
340 * position with the ELF binary image. (since size < total_size)
341 * So we first map the 'big' image - and unmap the remainder at
342 * the end. (which unmap is needed for ELF images with holes.)
343 */
344 if (total_size) {
345 total_size = ELF_PAGEALIGN(total_size);
346 map_addr = do_mmap(filep, addr, total_size, prot, type, off);
347 if (!BAD_ADDR(map_addr))
348 do_munmap(current->mm, map_addr+size, total_size-size);
349 } else
350 map_addr = do_mmap(filep, addr, size, prot, type, off);
351
Linus Torvalds1da177e2005-04-16 15:20:36 -0700352 up_write(&current->mm->mmap_sem);
353 return(map_addr);
354}
355
356#endif /* !elf_map */
357
Jiri Kosinacc503c12008-01-30 13:31:07 +0100358static unsigned long total_mapping_size(struct elf_phdr *cmds, int nr)
359{
360 int i, first_idx = -1, last_idx = -1;
361
362 for (i = 0; i < nr; i++) {
363 if (cmds[i].p_type == PT_LOAD) {
364 last_idx = i;
365 if (first_idx == -1)
366 first_idx = i;
367 }
368 }
369 if (first_idx == -1)
370 return 0;
371
372 return cmds[last_idx].p_vaddr + cmds[last_idx].p_memsz -
373 ELF_PAGESTART(cmds[first_idx].p_vaddr);
374}
375
376
Linus Torvalds1da177e2005-04-16 15:20:36 -0700377/* This is much more generalized than the library routine read function,
378 so we keep this separate. Technically the library read function
379 is only provided so that we can read a.out libraries that have
380 an ELF header */
381
Jesper Juhlf4e5cc22006-06-23 02:05:35 -0700382static unsigned long load_elf_interp(struct elfhdr *interp_elf_ex,
Jiri Kosinacc503c12008-01-30 13:31:07 +0100383 struct file *interpreter, unsigned long *interp_map_addr,
384 unsigned long no_base)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700385{
386 struct elf_phdr *elf_phdata;
387 struct elf_phdr *eppnt;
388 unsigned long load_addr = 0;
389 int load_addr_set = 0;
390 unsigned long last_bss = 0, elf_bss = 0;
391 unsigned long error = ~0UL;
Jiri Kosinacc503c12008-01-30 13:31:07 +0100392 unsigned long total_size;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700393 int retval, i, size;
394
395 /* First of all, some simple consistency checks */
396 if (interp_elf_ex->e_type != ET_EXEC &&
397 interp_elf_ex->e_type != ET_DYN)
398 goto out;
399 if (!elf_check_arch(interp_elf_ex))
400 goto out;
401 if (!interpreter->f_op || !interpreter->f_op->mmap)
402 goto out;
403
404 /*
405 * If the size of this structure has changed, then punt, since
406 * we will be doing the wrong thing.
407 */
408 if (interp_elf_ex->e_phentsize != sizeof(struct elf_phdr))
409 goto out;
410 if (interp_elf_ex->e_phnum < 1 ||
411 interp_elf_ex->e_phnum > 65536U / sizeof(struct elf_phdr))
412 goto out;
413
414 /* Now read in all of the header information */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700415 size = sizeof(struct elf_phdr) * interp_elf_ex->e_phnum;
416 if (size > ELF_MIN_ALIGN)
417 goto out;
Jesper Juhlf4e5cc22006-06-23 02:05:35 -0700418 elf_phdata = kmalloc(size, GFP_KERNEL);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700419 if (!elf_phdata)
420 goto out;
421
Jesper Juhlf4e5cc22006-06-23 02:05:35 -0700422 retval = kernel_read(interpreter, interp_elf_ex->e_phoff,
423 (char *)elf_phdata,size);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700424 error = -EIO;
425 if (retval != size) {
426 if (retval < 0)
427 error = retval;
428 goto out_close;
429 }
430
Jiri Kosinacc503c12008-01-30 13:31:07 +0100431 total_size = total_mapping_size(elf_phdata, interp_elf_ex->e_phnum);
432 if (!total_size) {
433 error = -EINVAL;
434 goto out_close;
435 }
436
Linus Torvalds1da177e2005-04-16 15:20:36 -0700437 eppnt = elf_phdata;
Jesper Juhlf4e5cc22006-06-23 02:05:35 -0700438 for (i = 0; i < interp_elf_ex->e_phnum; i++, eppnt++) {
439 if (eppnt->p_type == PT_LOAD) {
440 int elf_type = MAP_PRIVATE | MAP_DENYWRITE;
441 int elf_prot = 0;
442 unsigned long vaddr = 0;
443 unsigned long k, map_addr;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700444
Jesper Juhlf4e5cc22006-06-23 02:05:35 -0700445 if (eppnt->p_flags & PF_R)
446 elf_prot = PROT_READ;
447 if (eppnt->p_flags & PF_W)
448 elf_prot |= PROT_WRITE;
449 if (eppnt->p_flags & PF_X)
450 elf_prot |= PROT_EXEC;
451 vaddr = eppnt->p_vaddr;
452 if (interp_elf_ex->e_type == ET_EXEC || load_addr_set)
453 elf_type |= MAP_FIXED;
Jiri Kosinacc503c12008-01-30 13:31:07 +0100454 else if (no_base && interp_elf_ex->e_type == ET_DYN)
455 load_addr = -vaddr;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700456
Jesper Juhlf4e5cc22006-06-23 02:05:35 -0700457 map_addr = elf_map(interpreter, load_addr + vaddr,
Andrew Mortonbb1ad822008-01-30 13:31:07 +0100458 eppnt, elf_prot, elf_type, total_size);
Jiri Kosinacc503c12008-01-30 13:31:07 +0100459 total_size = 0;
460 if (!*interp_map_addr)
461 *interp_map_addr = map_addr;
Jesper Juhlf4e5cc22006-06-23 02:05:35 -0700462 error = map_addr;
463 if (BAD_ADDR(map_addr))
464 goto out_close;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700465
Jesper Juhlf4e5cc22006-06-23 02:05:35 -0700466 if (!load_addr_set &&
467 interp_elf_ex->e_type == ET_DYN) {
468 load_addr = map_addr - ELF_PAGESTART(vaddr);
469 load_addr_set = 1;
470 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700471
Jesper Juhlf4e5cc22006-06-23 02:05:35 -0700472 /*
473 * Check to see if the section's size will overflow the
474 * allowed task size. Note that p_filesz must always be
475 * <= p_memsize so it's only necessary to check p_memsz.
476 */
477 k = load_addr + eppnt->p_vaddr;
Chuck Ebbertce510592006-07-03 00:24:14 -0700478 if (BAD_ADDR(k) ||
Jesper Juhlf4e5cc22006-06-23 02:05:35 -0700479 eppnt->p_filesz > eppnt->p_memsz ||
480 eppnt->p_memsz > TASK_SIZE ||
481 TASK_SIZE - eppnt->p_memsz < k) {
482 error = -ENOMEM;
483 goto out_close;
484 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700485
Jesper Juhlf4e5cc22006-06-23 02:05:35 -0700486 /*
487 * Find the end of the file mapping for this phdr, and
488 * keep track of the largest address we see for this.
489 */
490 k = load_addr + eppnt->p_vaddr + eppnt->p_filesz;
491 if (k > elf_bss)
492 elf_bss = k;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700493
Jesper Juhlf4e5cc22006-06-23 02:05:35 -0700494 /*
495 * Do the same thing for the memory mapping - between
496 * elf_bss and last_bss is the bss section.
497 */
498 k = load_addr + eppnt->p_memsz + eppnt->p_vaddr;
499 if (k > last_bss)
500 last_bss = k;
501 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700502 }
503
Linus Torvalds1da177e2005-04-16 15:20:36 -0700504 if (last_bss > elf_bss) {
Roland McGrath752015d2009-09-08 19:49:40 -0700505 /*
506 * Now fill out the bss section. First pad the last page up
507 * to the page boundary, and then perform a mmap to make sure
508 * that there are zero-mapped pages up to and including the
509 * last bss page.
510 */
511 if (padzero(elf_bss)) {
512 error = -EFAULT;
513 goto out_close;
514 }
515
516 /* What we have mapped so far */
517 elf_bss = ELF_PAGESTART(elf_bss + ELF_MIN_ALIGN - 1);
518
519 /* Map the last of the bss segment */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700520 down_write(&current->mm->mmap_sem);
521 error = do_brk(elf_bss, last_bss - elf_bss);
522 up_write(&current->mm->mmap_sem);
523 if (BAD_ADDR(error))
524 goto out_close;
525 }
526
Jiri Kosinacc503c12008-01-30 13:31:07 +0100527 error = load_addr;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700528
529out_close:
530 kfree(elf_phdata);
531out:
532 return error;
533}
534
Linus Torvalds1da177e2005-04-16 15:20:36 -0700535/*
536 * These are the functions used to load ELF style executables and shared
537 * libraries. There is no binary dependent code anywhere else.
538 */
539
540#define INTERPRETER_NONE 0
Linus Torvalds1da177e2005-04-16 15:20:36 -0700541#define INTERPRETER_ELF 2
542
Andi Kleen913bd902006-03-25 16:29:09 +0100543#ifndef STACK_RND_MASK
James Bottomleyd1cabd62007-03-16 13:38:35 -0800544#define STACK_RND_MASK (0x7ff >> (PAGE_SHIFT - 12)) /* 8MB of VA */
Andi Kleen913bd902006-03-25 16:29:09 +0100545#endif
Linus Torvalds1da177e2005-04-16 15:20:36 -0700546
547static unsigned long randomize_stack_top(unsigned long stack_top)
548{
549 unsigned int random_variable = 0;
550
Andi Kleenc16b63e2006-09-26 10:52:28 +0200551 if ((current->flags & PF_RANDOMIZE) &&
552 !(current->personality & ADDR_NO_RANDOMIZE)) {
Andi Kleen913bd902006-03-25 16:29:09 +0100553 random_variable = get_random_int() & STACK_RND_MASK;
554 random_variable <<= PAGE_SHIFT;
555 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700556#ifdef CONFIG_STACK_GROWSUP
Andi Kleen913bd902006-03-25 16:29:09 +0100557 return PAGE_ALIGN(stack_top) + random_variable;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700558#else
Andi Kleen913bd902006-03-25 16:29:09 +0100559 return PAGE_ALIGN(stack_top) - random_variable;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700560#endif
561}
562
Jesper Juhlf4e5cc22006-06-23 02:05:35 -0700563static int load_elf_binary(struct linux_binprm *bprm, struct pt_regs *regs)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700564{
565 struct file *interpreter = NULL; /* to shut gcc up */
566 unsigned long load_addr = 0, load_bias = 0;
567 int load_addr_set = 0;
568 char * elf_interpreter = NULL;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700569 unsigned long error;
Jesper Juhlf4e5cc22006-06-23 02:05:35 -0700570 struct elf_phdr *elf_ppnt, *elf_phdata;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700571 unsigned long elf_bss, elf_brk;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700572 int retval, i;
573 unsigned int size;
Jiri Kosinacc503c12008-01-30 13:31:07 +0100574 unsigned long elf_entry;
575 unsigned long interp_load_addr = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700576 unsigned long start_code, end_code, start_data, end_data;
577 unsigned long reloc_func_desc = 0;
David Rientjes8de61e62006-12-06 20:40:16 -0800578 int executable_stack = EXSTACK_DEFAULT;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700579 unsigned long def_flags = 0;
580 struct {
581 struct elfhdr elf_ex;
582 struct elfhdr interp_elf_ex;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700583 } *loc;
584
585 loc = kmalloc(sizeof(*loc), GFP_KERNEL);
586 if (!loc) {
587 retval = -ENOMEM;
588 goto out_ret;
589 }
590
591 /* Get the exec-header */
Jesper Juhlf4e5cc22006-06-23 02:05:35 -0700592 loc->elf_ex = *((struct elfhdr *)bprm->buf);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700593
594 retval = -ENOEXEC;
595 /* First of all, some simple consistency checks */
596 if (memcmp(loc->elf_ex.e_ident, ELFMAG, SELFMAG) != 0)
597 goto out;
598
599 if (loc->elf_ex.e_type != ET_EXEC && loc->elf_ex.e_type != ET_DYN)
600 goto out;
601 if (!elf_check_arch(&loc->elf_ex))
602 goto out;
603 if (!bprm->file->f_op||!bprm->file->f_op->mmap)
604 goto out;
605
606 /* Now read in all of the header information */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700607 if (loc->elf_ex.e_phentsize != sizeof(struct elf_phdr))
608 goto out;
609 if (loc->elf_ex.e_phnum < 1 ||
610 loc->elf_ex.e_phnum > 65536U / sizeof(struct elf_phdr))
611 goto out;
612 size = loc->elf_ex.e_phnum * sizeof(struct elf_phdr);
613 retval = -ENOMEM;
Jesper Juhlf4e5cc22006-06-23 02:05:35 -0700614 elf_phdata = kmalloc(size, GFP_KERNEL);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700615 if (!elf_phdata)
616 goto out;
617
Jesper Juhlf4e5cc22006-06-23 02:05:35 -0700618 retval = kernel_read(bprm->file, loc->elf_ex.e_phoff,
619 (char *)elf_phdata, size);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700620 if (retval != size) {
621 if (retval >= 0)
622 retval = -EIO;
623 goto out_free_ph;
624 }
625
Linus Torvalds1da177e2005-04-16 15:20:36 -0700626 elf_ppnt = elf_phdata;
627 elf_bss = 0;
628 elf_brk = 0;
629
630 start_code = ~0UL;
631 end_code = 0;
632 start_data = 0;
633 end_data = 0;
634
635 for (i = 0; i < loc->elf_ex.e_phnum; i++) {
636 if (elf_ppnt->p_type == PT_INTERP) {
637 /* This is the program interpreter used for
638 * shared libraries - for now assume that this
639 * is an a.out format binary
640 */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700641 retval = -ENOEXEC;
642 if (elf_ppnt->p_filesz > PATH_MAX ||
643 elf_ppnt->p_filesz < 2)
Al Viroe7b9b552009-03-29 16:31:16 -0400644 goto out_free_ph;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700645
646 retval = -ENOMEM;
Jesper Juhl792db3a2006-01-09 20:54:45 -0800647 elf_interpreter = kmalloc(elf_ppnt->p_filesz,
Jesper Juhlf4e5cc22006-06-23 02:05:35 -0700648 GFP_KERNEL);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700649 if (!elf_interpreter)
Al Viroe7b9b552009-03-29 16:31:16 -0400650 goto out_free_ph;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700651
652 retval = kernel_read(bprm->file, elf_ppnt->p_offset,
Jesper Juhlf4e5cc22006-06-23 02:05:35 -0700653 elf_interpreter,
654 elf_ppnt->p_filesz);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700655 if (retval != elf_ppnt->p_filesz) {
656 if (retval >= 0)
657 retval = -EIO;
658 goto out_free_interp;
659 }
660 /* make sure path is NULL terminated */
661 retval = -ENOEXEC;
662 if (elf_interpreter[elf_ppnt->p_filesz - 1] != '\0')
663 goto out_free_interp;
664
Linus Torvalds1da177e2005-04-16 15:20:36 -0700665 /*
666 * The early SET_PERSONALITY here is so that the lookup
667 * for the interpreter happens in the namespace of the
668 * to-be-execed image. SET_PERSONALITY can select an
669 * alternate root.
670 *
671 * However, SET_PERSONALITY is NOT allowed to switch
672 * this task into the new images's memory mapping
673 * policy - that is, TASK_SIZE must still evaluate to
674 * that which is appropriate to the execing application.
675 * This is because exit_mmap() needs to have TASK_SIZE
676 * evaluate to the size of the old image.
677 *
678 * So if (say) a 64-bit application is execing a 32-bit
679 * application it is the architecture's responsibility
680 * to defer changing the value of TASK_SIZE until the
681 * switch really is going to happen - do this in
682 * flush_thread(). - akpm
683 */
Martin Schwidefsky0b592682008-10-16 15:39:57 +0200684 SET_PERSONALITY(loc->elf_ex);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700685
686 interpreter = open_exec(elf_interpreter);
687 retval = PTR_ERR(interpreter);
688 if (IS_ERR(interpreter))
689 goto out_free_interp;
Alexey Dobriyan1fb84492007-01-26 00:57:16 -0800690
691 /*
692 * If the binary is not readable then enforce
693 * mm->dumpable = 0 regardless of the interpreter's
694 * permissions.
695 */
696 if (file_permission(interpreter, MAY_READ) < 0)
697 bprm->interp_flags |= BINPRM_FLAGS_ENFORCE_NONDUMP;
698
Jesper Juhlf4e5cc22006-06-23 02:05:35 -0700699 retval = kernel_read(interpreter, 0, bprm->buf,
700 BINPRM_BUF_SIZE);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700701 if (retval != BINPRM_BUF_SIZE) {
702 if (retval >= 0)
703 retval = -EIO;
704 goto out_free_dentry;
705 }
706
707 /* Get the exec headers */
Jesper Juhlf4e5cc22006-06-23 02:05:35 -0700708 loc->interp_elf_ex = *((struct elfhdr *)bprm->buf);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700709 break;
710 }
711 elf_ppnt++;
712 }
713
714 elf_ppnt = elf_phdata;
715 for (i = 0; i < loc->elf_ex.e_phnum; i++, elf_ppnt++)
716 if (elf_ppnt->p_type == PT_GNU_STACK) {
717 if (elf_ppnt->p_flags & PF_X)
718 executable_stack = EXSTACK_ENABLE_X;
719 else
720 executable_stack = EXSTACK_DISABLE_X;
721 break;
722 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700723
724 /* Some simple consistency checks for the interpreter */
725 if (elf_interpreter) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700726 retval = -ELIBBAD;
Andi Kleend20894a2008-02-08 04:21:54 -0800727 /* Not an ELF interpreter */
728 if (memcmp(loc->interp_elf_ex.e_ident, ELFMAG, SELFMAG) != 0)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700729 goto out_free_dentry;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700730 /* Verify the interpreter has a valid arch */
Andi Kleend20894a2008-02-08 04:21:54 -0800731 if (!elf_check_arch(&loc->interp_elf_ex))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700732 goto out_free_dentry;
733 } else {
734 /* Executables without an interpreter also need a personality */
Martin Schwidefsky0b592682008-10-16 15:39:57 +0200735 SET_PERSONALITY(loc->elf_ex);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700736 }
737
Linus Torvalds1da177e2005-04-16 15:20:36 -0700738 /* Flush all traces of the currently running executable */
739 retval = flush_old_exec(bprm);
740 if (retval)
741 goto out_free_dentry;
742
Linus Torvalds1da177e2005-04-16 15:20:36 -0700743 /* OK, This is the point of no return */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700744 current->flags &= ~PF_FORKNOEXEC;
745 current->mm->def_flags = def_flags;
746
747 /* Do this immediately, since STACK_TOP as used in setup_arg_pages
748 may depend on the personality. */
Martin Schwidefsky0b592682008-10-16 15:39:57 +0200749 SET_PERSONALITY(loc->elf_ex);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700750 if (elf_read_implies_exec(loc->elf_ex, executable_stack))
751 current->personality |= READ_IMPLIES_EXEC;
752
Jesper Juhlf4e5cc22006-06-23 02:05:35 -0700753 if (!(current->personality & ADDR_NO_RANDOMIZE) && randomize_va_space)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700754 current->flags |= PF_RANDOMIZE;
755 arch_pick_mmap_layout(current->mm);
756
757 /* Do this so that we can load the interpreter, if need be. We will
758 change some of these later */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700759 current->mm->free_area_cache = current->mm->mmap_base;
Wolfgang Wander1363c3c2005-06-21 17:14:49 -0700760 current->mm->cached_hole_size = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700761 retval = setup_arg_pages(bprm, randomize_stack_top(STACK_TOP),
762 executable_stack);
763 if (retval < 0) {
764 send_sig(SIGKILL, current, 0);
765 goto out_free_dentry;
766 }
767
Linus Torvalds1da177e2005-04-16 15:20:36 -0700768 current->mm->start_stack = bprm->p;
769
770 /* Now we do a little grungy work by mmaping the ELF image into
Jiri Kosinacc503c12008-01-30 13:31:07 +0100771 the correct location in memory. */
Jesper Juhlf4e5cc22006-06-23 02:05:35 -0700772 for(i = 0, elf_ppnt = elf_phdata;
773 i < loc->elf_ex.e_phnum; i++, elf_ppnt++) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700774 int elf_prot = 0, elf_flags;
775 unsigned long k, vaddr;
776
777 if (elf_ppnt->p_type != PT_LOAD)
778 continue;
779
780 if (unlikely (elf_brk > elf_bss)) {
781 unsigned long nbyte;
782
783 /* There was a PT_LOAD segment with p_memsz > p_filesz
784 before this one. Map anonymous pages, if needed,
785 and clear the area. */
786 retval = set_brk (elf_bss + load_bias,
787 elf_brk + load_bias);
788 if (retval) {
789 send_sig(SIGKILL, current, 0);
790 goto out_free_dentry;
791 }
792 nbyte = ELF_PAGEOFFSET(elf_bss);
793 if (nbyte) {
794 nbyte = ELF_MIN_ALIGN - nbyte;
795 if (nbyte > elf_brk - elf_bss)
796 nbyte = elf_brk - elf_bss;
797 if (clear_user((void __user *)elf_bss +
798 load_bias, nbyte)) {
799 /*
800 * This bss-zeroing can fail if the ELF
Jesper Juhlf4e5cc22006-06-23 02:05:35 -0700801 * file specifies odd protections. So
Linus Torvalds1da177e2005-04-16 15:20:36 -0700802 * we don't check the return value
803 */
804 }
805 }
806 }
807
Jesper Juhlf4e5cc22006-06-23 02:05:35 -0700808 if (elf_ppnt->p_flags & PF_R)
809 elf_prot |= PROT_READ;
810 if (elf_ppnt->p_flags & PF_W)
811 elf_prot |= PROT_WRITE;
812 if (elf_ppnt->p_flags & PF_X)
813 elf_prot |= PROT_EXEC;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700814
Jesper Juhlf4e5cc22006-06-23 02:05:35 -0700815 elf_flags = MAP_PRIVATE | MAP_DENYWRITE | MAP_EXECUTABLE;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700816
817 vaddr = elf_ppnt->p_vaddr;
818 if (loc->elf_ex.e_type == ET_EXEC || load_addr_set) {
819 elf_flags |= MAP_FIXED;
820 } else if (loc->elf_ex.e_type == ET_DYN) {
Jesper Juhlf4e5cc22006-06-23 02:05:35 -0700821 /* Try and get dynamic programs out of the way of the
822 * default mmap base, as well as whatever program they
823 * might try to exec. This is because the brk will
824 * follow the loader, and is not movable. */
Jiri Kosinacc503c12008-01-30 13:31:07 +0100825#ifdef CONFIG_X86
826 load_bias = 0;
827#else
Linus Torvalds90cb28e2007-01-06 13:28:21 -0800828 load_bias = ELF_PAGESTART(ELF_ET_DYN_BASE - vaddr);
Jiri Kosinacc503c12008-01-30 13:31:07 +0100829#endif
Linus Torvalds1da177e2005-04-16 15:20:36 -0700830 }
831
Jesper Juhlf4e5cc22006-06-23 02:05:35 -0700832 error = elf_map(bprm->file, load_bias + vaddr, elf_ppnt,
Andrew Mortonbb1ad822008-01-30 13:31:07 +0100833 elf_prot, elf_flags, 0);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700834 if (BAD_ADDR(error)) {
835 send_sig(SIGKILL, current, 0);
Alexey Kuznetsovb140f252007-05-08 00:31:57 -0700836 retval = IS_ERR((void *)error) ?
837 PTR_ERR((void*)error) : -EINVAL;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700838 goto out_free_dentry;
839 }
840
841 if (!load_addr_set) {
842 load_addr_set = 1;
843 load_addr = (elf_ppnt->p_vaddr - elf_ppnt->p_offset);
844 if (loc->elf_ex.e_type == ET_DYN) {
845 load_bias += error -
846 ELF_PAGESTART(load_bias + vaddr);
847 load_addr += load_bias;
848 reloc_func_desc = load_bias;
849 }
850 }
851 k = elf_ppnt->p_vaddr;
Jesper Juhlf4e5cc22006-06-23 02:05:35 -0700852 if (k < start_code)
853 start_code = k;
854 if (start_data < k)
855 start_data = k;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700856
857 /*
858 * Check to see if the section's size will overflow the
859 * allowed task size. Note that p_filesz must always be
860 * <= p_memsz so it is only necessary to check p_memsz.
861 */
Chuck Ebbertce510592006-07-03 00:24:14 -0700862 if (BAD_ADDR(k) || elf_ppnt->p_filesz > elf_ppnt->p_memsz ||
Linus Torvalds1da177e2005-04-16 15:20:36 -0700863 elf_ppnt->p_memsz > TASK_SIZE ||
864 TASK_SIZE - elf_ppnt->p_memsz < k) {
Jesper Juhlf4e5cc22006-06-23 02:05:35 -0700865 /* set_brk can never work. Avoid overflows. */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700866 send_sig(SIGKILL, current, 0);
Alexey Kuznetsovb140f252007-05-08 00:31:57 -0700867 retval = -EINVAL;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700868 goto out_free_dentry;
869 }
870
871 k = elf_ppnt->p_vaddr + elf_ppnt->p_filesz;
872
873 if (k > elf_bss)
874 elf_bss = k;
875 if ((elf_ppnt->p_flags & PF_X) && end_code < k)
876 end_code = k;
877 if (end_data < k)
878 end_data = k;
879 k = elf_ppnt->p_vaddr + elf_ppnt->p_memsz;
880 if (k > elf_brk)
881 elf_brk = k;
882 }
883
884 loc->elf_ex.e_entry += load_bias;
885 elf_bss += load_bias;
886 elf_brk += load_bias;
887 start_code += load_bias;
888 end_code += load_bias;
889 start_data += load_bias;
890 end_data += load_bias;
891
892 /* Calling set_brk effectively mmaps the pages that we need
893 * for the bss and break sections. We must do this before
894 * mapping in the interpreter, to make sure it doesn't wind
895 * up getting placed where the bss needs to go.
896 */
897 retval = set_brk(elf_bss, elf_brk);
898 if (retval) {
899 send_sig(SIGKILL, current, 0);
900 goto out_free_dentry;
901 }
akpm@osdl.org6de50512005-10-11 08:29:08 -0700902 if (likely(elf_bss != elf_brk) && unlikely(padzero(elf_bss))) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700903 send_sig(SIGSEGV, current, 0);
904 retval = -EFAULT; /* Nobody gets to see this, but.. */
905 goto out_free_dentry;
906 }
907
908 if (elf_interpreter) {
Andi Kleend20894a2008-02-08 04:21:54 -0800909 unsigned long uninitialized_var(interp_map_addr);
Jiri Kosinacc503c12008-01-30 13:31:07 +0100910
Andi Kleend20894a2008-02-08 04:21:54 -0800911 elf_entry = load_elf_interp(&loc->interp_elf_ex,
912 interpreter,
913 &interp_map_addr,
914 load_bias);
915 if (!IS_ERR((void *)elf_entry)) {
916 /*
917 * load_elf_interp() returns relocation
918 * adjustment
919 */
920 interp_load_addr = elf_entry;
921 elf_entry += loc->interp_elf_ex.e_entry;
Jiri Kosinacc503c12008-01-30 13:31:07 +0100922 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700923 if (BAD_ADDR(elf_entry)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700924 force_sig(SIGSEGV, current);
Chuck Ebbertce510592006-07-03 00:24:14 -0700925 retval = IS_ERR((void *)elf_entry) ?
926 (int)elf_entry : -EINVAL;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700927 goto out_free_dentry;
928 }
929 reloc_func_desc = interp_load_addr;
930
931 allow_write_access(interpreter);
932 fput(interpreter);
933 kfree(elf_interpreter);
934 } else {
935 elf_entry = loc->elf_ex.e_entry;
Suresh Siddha5342fba2006-02-26 04:18:28 +0100936 if (BAD_ADDR(elf_entry)) {
Chuck Ebbertce510592006-07-03 00:24:14 -0700937 force_sig(SIGSEGV, current);
938 retval = -EINVAL;
Suresh Siddha5342fba2006-02-26 04:18:28 +0100939 goto out_free_dentry;
940 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700941 }
942
943 kfree(elf_phdata);
944
Linus Torvalds1da177e2005-04-16 15:20:36 -0700945 set_binfmt(&elf_format);
946
Benjamin Herrenschmidt547ee842005-04-16 15:24:35 -0700947#ifdef ARCH_HAS_SETUP_ADDITIONAL_PAGES
Martin Schwidefskyfc5243d2008-12-25 13:38:35 +0100948 retval = arch_setup_additional_pages(bprm, !!elf_interpreter);
Benjamin Herrenschmidt547ee842005-04-16 15:24:35 -0700949 if (retval < 0) {
950 send_sig(SIGKILL, current, 0);
Roland McGrath18c8baf2005-04-28 15:17:19 -0700951 goto out;
Benjamin Herrenschmidt547ee842005-04-16 15:24:35 -0700952 }
953#endif /* ARCH_HAS_SETUP_ADDITIONAL_PAGES */
954
David Howellsa6f76f22008-11-14 10:39:24 +1100955 install_exec_creds(bprm);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700956 current->flags &= ~PF_FORKNOEXEC;
Ollie Wildb6a2fea2007-07-19 01:48:16 -0700957 retval = create_elf_tables(bprm, &loc->elf_ex,
Jesper Juhlf4e5cc22006-06-23 02:05:35 -0700958 load_addr, interp_load_addr);
Ollie Wildb6a2fea2007-07-19 01:48:16 -0700959 if (retval < 0) {
960 send_sig(SIGKILL, current, 0);
961 goto out;
962 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700963 /* N.B. passed_fileno might not be initialized? */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700964 current->mm->end_code = end_code;
965 current->mm->start_code = start_code;
966 current->mm->start_data = start_data;
967 current->mm->end_data = end_data;
968 current->mm->start_stack = bprm->p;
969
Jiri Kosinac1d171a2008-01-30 13:30:40 +0100970#ifdef arch_randomize_brk
Ingo Molnar32a93232008-02-06 22:39:44 +0100971 if ((current->flags & PF_RANDOMIZE) && (randomize_va_space > 1))
Jiri Kosinac1d171a2008-01-30 13:30:40 +0100972 current->mm->brk = current->mm->start_brk =
973 arch_randomize_brk(current->mm);
974#endif
975
Linus Torvalds1da177e2005-04-16 15:20:36 -0700976 if (current->personality & MMAP_PAGE_ZERO) {
977 /* Why this, you ask??? Well SVr4 maps page 0 as read-only,
978 and some applications "depend" upon this behavior.
979 Since we do not have the power to recompile these, we
Jesper Juhlf4e5cc22006-06-23 02:05:35 -0700980 emulate the SVr4 behavior. Sigh. */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700981 down_write(&current->mm->mmap_sem);
982 error = do_mmap(NULL, 0, PAGE_SIZE, PROT_READ | PROT_EXEC,
983 MAP_FIXED | MAP_PRIVATE, 0);
984 up_write(&current->mm->mmap_sem);
985 }
986
987#ifdef ELF_PLAT_INIT
988 /*
989 * The ABI may specify that certain registers be set up in special
990 * ways (on i386 %edx is the address of a DT_FINI function, for
991 * example. In addition, it may also specify (eg, PowerPC64 ELF)
992 * that the e_entry field is the address of the function descriptor
993 * for the startup routine, rather than the address of the startup
994 * routine itself. This macro performs whatever initialization to
995 * the regs structure is required as well as any relocations to the
996 * function descriptor entries when executing dynamically links apps.
997 */
998 ELF_PLAT_INIT(regs, reloc_func_desc);
999#endif
1000
1001 start_thread(regs, elf_entry, bprm->p);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001002 retval = 0;
1003out:
1004 kfree(loc);
1005out_ret:
1006 return retval;
1007
1008 /* error cleanup */
1009out_free_dentry:
1010 allow_write_access(interpreter);
1011 if (interpreter)
1012 fput(interpreter);
1013out_free_interp:
Jesper Juhlf99d49a2005-11-07 01:01:34 -08001014 kfree(elf_interpreter);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001015out_free_ph:
1016 kfree(elf_phdata);
1017 goto out;
1018}
1019
1020/* This is really simpleminded and specialized - we are loading an
1021 a.out library that is given an ELF header. */
Linus Torvalds1da177e2005-04-16 15:20:36 -07001022static int load_elf_library(struct file *file)
1023{
1024 struct elf_phdr *elf_phdata;
1025 struct elf_phdr *eppnt;
1026 unsigned long elf_bss, bss, len;
1027 int retval, error, i, j;
1028 struct elfhdr elf_ex;
1029
1030 error = -ENOEXEC;
Jesper Juhlf4e5cc22006-06-23 02:05:35 -07001031 retval = kernel_read(file, 0, (char *)&elf_ex, sizeof(elf_ex));
Linus Torvalds1da177e2005-04-16 15:20:36 -07001032 if (retval != sizeof(elf_ex))
1033 goto out;
1034
1035 if (memcmp(elf_ex.e_ident, ELFMAG, SELFMAG) != 0)
1036 goto out;
1037
1038 /* First of all, some simple consistency checks */
1039 if (elf_ex.e_type != ET_EXEC || elf_ex.e_phnum > 2 ||
Jesper Juhlf4e5cc22006-06-23 02:05:35 -07001040 !elf_check_arch(&elf_ex) || !file->f_op || !file->f_op->mmap)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001041 goto out;
1042
1043 /* Now read in all of the header information */
1044
1045 j = sizeof(struct elf_phdr) * elf_ex.e_phnum;
1046 /* j < ELF_MIN_ALIGN because elf_ex.e_phnum <= 2 */
1047
1048 error = -ENOMEM;
1049 elf_phdata = kmalloc(j, GFP_KERNEL);
1050 if (!elf_phdata)
1051 goto out;
1052
1053 eppnt = elf_phdata;
1054 error = -ENOEXEC;
1055 retval = kernel_read(file, elf_ex.e_phoff, (char *)eppnt, j);
1056 if (retval != j)
1057 goto out_free_ph;
1058
1059 for (j = 0, i = 0; i<elf_ex.e_phnum; i++)
1060 if ((eppnt + i)->p_type == PT_LOAD)
1061 j++;
1062 if (j != 1)
1063 goto out_free_ph;
1064
1065 while (eppnt->p_type != PT_LOAD)
1066 eppnt++;
1067
1068 /* Now use mmap to map the library into memory. */
1069 down_write(&current->mm->mmap_sem);
1070 error = do_mmap(file,
1071 ELF_PAGESTART(eppnt->p_vaddr),
1072 (eppnt->p_filesz +
1073 ELF_PAGEOFFSET(eppnt->p_vaddr)),
1074 PROT_READ | PROT_WRITE | PROT_EXEC,
1075 MAP_FIXED | MAP_PRIVATE | MAP_DENYWRITE,
1076 (eppnt->p_offset -
1077 ELF_PAGEOFFSET(eppnt->p_vaddr)));
1078 up_write(&current->mm->mmap_sem);
1079 if (error != ELF_PAGESTART(eppnt->p_vaddr))
1080 goto out_free_ph;
1081
1082 elf_bss = eppnt->p_vaddr + eppnt->p_filesz;
1083 if (padzero(elf_bss)) {
1084 error = -EFAULT;
1085 goto out_free_ph;
1086 }
1087
Jesper Juhlf4e5cc22006-06-23 02:05:35 -07001088 len = ELF_PAGESTART(eppnt->p_filesz + eppnt->p_vaddr +
1089 ELF_MIN_ALIGN - 1);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001090 bss = eppnt->p_memsz + eppnt->p_vaddr;
1091 if (bss > len) {
1092 down_write(&current->mm->mmap_sem);
1093 do_brk(len, bss - len);
1094 up_write(&current->mm->mmap_sem);
1095 }
1096 error = 0;
1097
1098out_free_ph:
1099 kfree(elf_phdata);
1100out:
1101 return error;
1102}
1103
1104/*
1105 * Note that some platforms still use traditional core dumps and not
1106 * the ELF core dump. Each platform can select it as appropriate.
1107 */
Matt Mackall708e9a72006-01-08 01:05:25 -08001108#if defined(USE_ELF_CORE_DUMP) && defined(CONFIG_ELF_CORE)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001109
1110/*
1111 * ELF core dumper
1112 *
1113 * Modelled on fs/exec.c:aout_core_dump()
1114 * Jeremy Fitzhardinge <jeremy@sw.oz.au>
1115 */
1116/*
1117 * These are the only things you should do on a core-file: use only these
1118 * functions to write out all the necessary info.
1119 */
1120static int dump_write(struct file *file, const void *addr, int nr)
1121{
1122 return file->f_op->write(file, addr, nr, &file->f_pos) == nr;
1123}
1124
Daniel Jacobowitz5db92852005-06-15 22:26:34 -07001125static int dump_seek(struct file *file, loff_t off)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001126{
Andi Kleend025c9d2006-09-30 23:29:28 -07001127 if (file->f_op->llseek && file->f_op->llseek != no_llseek) {
Petr Vandrovec7f14daa2006-10-13 04:13:16 +02001128 if (file->f_op->llseek(file, off, SEEK_CUR) < 0)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001129 return 0;
Andi Kleend025c9d2006-09-30 23:29:28 -07001130 } else {
1131 char *buf = (char *)get_zeroed_page(GFP_KERNEL);
1132 if (!buf)
1133 return 0;
1134 while (off > 0) {
1135 unsigned long n = off;
1136 if (n > PAGE_SIZE)
1137 n = PAGE_SIZE;
1138 if (!dump_write(file, buf, n))
1139 return 0;
1140 off -= n;
1141 }
1142 free_page((unsigned long)buf);
1143 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001144 return 1;
1145}
1146
1147/*
Roland McGrath82df3972007-10-16 23:27:02 -07001148 * Decide what to dump of a segment, part, all or none.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001149 */
Roland McGrath82df3972007-10-16 23:27:02 -07001150static unsigned long vma_dump_size(struct vm_area_struct *vma,
1151 unsigned long mm_flags)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001152{
KOSAKI Motohiroe575f112008-10-18 20:27:08 -07001153#define FILTER(type) (mm_flags & (1UL << MMF_DUMP_##type))
1154
Roland McGrathe5b97dd2007-01-26 00:56:48 -08001155 /* The vma can be set up to tell us the answer directly. */
1156 if (vma->vm_flags & VM_ALWAYSDUMP)
Roland McGrath82df3972007-10-16 23:27:02 -07001157 goto whole;
Roland McGrathe5b97dd2007-01-26 00:56:48 -08001158
KOSAKI Motohiroe575f112008-10-18 20:27:08 -07001159 /* Hugetlb memory check */
1160 if (vma->vm_flags & VM_HUGETLB) {
1161 if ((vma->vm_flags & VM_SHARED) && FILTER(HUGETLB_SHARED))
1162 goto whole;
1163 if (!(vma->vm_flags & VM_SHARED) && FILTER(HUGETLB_PRIVATE))
1164 goto whole;
1165 }
1166
Linus Torvalds1da177e2005-04-16 15:20:36 -07001167 /* Do not dump I/O mapped devices or special mappings */
1168 if (vma->vm_flags & (VM_IO | VM_RESERVED))
1169 return 0;
1170
Kawai, Hidehiroa1b59e82007-07-19 01:48:29 -07001171 /* By default, dump shared memory if mapped from an anonymous file. */
1172 if (vma->vm_flags & VM_SHARED) {
Roland McGrath82df3972007-10-16 23:27:02 -07001173 if (vma->vm_file->f_path.dentry->d_inode->i_nlink == 0 ?
1174 FILTER(ANON_SHARED) : FILTER(MAPPED_SHARED))
1175 goto whole;
1176 return 0;
Kawai, Hidehiroa1b59e82007-07-19 01:48:29 -07001177 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001178
Roland McGrath82df3972007-10-16 23:27:02 -07001179 /* Dump segments that have been written to. */
1180 if (vma->anon_vma && FILTER(ANON_PRIVATE))
1181 goto whole;
1182 if (vma->vm_file == NULL)
1183 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001184
Roland McGrath82df3972007-10-16 23:27:02 -07001185 if (FILTER(MAPPED_PRIVATE))
1186 goto whole;
1187
1188 /*
1189 * If this looks like the beginning of a DSO or executable mapping,
1190 * check for an ELF header. If we find one, dump the first page to
1191 * aid in determining what was mapped here.
1192 */
Roland McGrath92dc07b2009-02-06 17:34:07 -08001193 if (FILTER(ELF_HEADERS) &&
1194 vma->vm_pgoff == 0 && (vma->vm_flags & VM_READ)) {
Roland McGrath82df3972007-10-16 23:27:02 -07001195 u32 __user *header = (u32 __user *) vma->vm_start;
1196 u32 word;
Roland McGrath92dc07b2009-02-06 17:34:07 -08001197 mm_segment_t fs = get_fs();
Roland McGrath82df3972007-10-16 23:27:02 -07001198 /*
1199 * Doing it this way gets the constant folded by GCC.
1200 */
1201 union {
1202 u32 cmp;
1203 char elfmag[SELFMAG];
1204 } magic;
1205 BUILD_BUG_ON(SELFMAG != sizeof word);
1206 magic.elfmag[EI_MAG0] = ELFMAG0;
1207 magic.elfmag[EI_MAG1] = ELFMAG1;
1208 magic.elfmag[EI_MAG2] = ELFMAG2;
1209 magic.elfmag[EI_MAG3] = ELFMAG3;
Roland McGrath92dc07b2009-02-06 17:34:07 -08001210 /*
1211 * Switch to the user "segment" for get_user(),
1212 * then put back what elf_core_dump() had in place.
1213 */
1214 set_fs(USER_DS);
1215 if (unlikely(get_user(word, header)))
1216 word = 0;
1217 set_fs(fs);
1218 if (word == magic.cmp)
Roland McGrath82df3972007-10-16 23:27:02 -07001219 return PAGE_SIZE;
1220 }
1221
1222#undef FILTER
1223
1224 return 0;
1225
1226whole:
1227 return vma->vm_end - vma->vm_start;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001228}
1229
Linus Torvalds1da177e2005-04-16 15:20:36 -07001230/* An ELF note in memory */
1231struct memelfnote
1232{
1233 const char *name;
1234 int type;
1235 unsigned int datasz;
1236 void *data;
1237};
1238
1239static int notesize(struct memelfnote *en)
1240{
1241 int sz;
1242
1243 sz = sizeof(struct elf_note);
1244 sz += roundup(strlen(en->name) + 1, 4);
1245 sz += roundup(en->datasz, 4);
1246
1247 return sz;
1248}
1249
Andi Kleend025c9d2006-09-30 23:29:28 -07001250#define DUMP_WRITE(addr, nr, foffset) \
1251 do { if (!dump_write(file, (addr), (nr))) return 0; *foffset += (nr); } while(0)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001252
Andi Kleend025c9d2006-09-30 23:29:28 -07001253static int alignfile(struct file *file, loff_t *foffset)
1254{
Petr Vandroveca7a0d862006-10-13 18:42:07 +02001255 static const char buf[4] = { 0, };
Andi Kleend025c9d2006-09-30 23:29:28 -07001256 DUMP_WRITE(buf, roundup(*foffset, 4) - *foffset, foffset);
1257 return 1;
1258}
1259
1260static int writenote(struct memelfnote *men, struct file *file,
1261 loff_t *foffset)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001262{
1263 struct elf_note en;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001264 en.n_namesz = strlen(men->name) + 1;
1265 en.n_descsz = men->datasz;
1266 en.n_type = men->type;
1267
Andi Kleend025c9d2006-09-30 23:29:28 -07001268 DUMP_WRITE(&en, sizeof(en), foffset);
1269 DUMP_WRITE(men->name, en.n_namesz, foffset);
1270 if (!alignfile(file, foffset))
1271 return 0;
1272 DUMP_WRITE(men->data, men->datasz, foffset);
1273 if (!alignfile(file, foffset))
1274 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001275
1276 return 1;
1277}
1278#undef DUMP_WRITE
Linus Torvalds1da177e2005-04-16 15:20:36 -07001279
1280#define DUMP_WRITE(addr, nr) \
1281 if ((size += (nr)) > limit || !dump_write(file, (addr), (nr))) \
1282 goto end_coredump;
1283#define DUMP_SEEK(off) \
1284 if (!dump_seek(file, (off))) \
1285 goto end_coredump;
1286
Roland McGrath3aba4812008-01-30 13:31:44 +01001287static void fill_elf_header(struct elfhdr *elf, int segs,
1288 u16 machine, u32 flags, u8 osabi)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001289{
Cyrill Gorcunov6970c8e2008-04-29 01:01:18 -07001290 memset(elf, 0, sizeof(*elf));
1291
Linus Torvalds1da177e2005-04-16 15:20:36 -07001292 memcpy(elf->e_ident, ELFMAG, SELFMAG);
1293 elf->e_ident[EI_CLASS] = ELF_CLASS;
1294 elf->e_ident[EI_DATA] = ELF_DATA;
1295 elf->e_ident[EI_VERSION] = EV_CURRENT;
1296 elf->e_ident[EI_OSABI] = ELF_OSABI;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001297
1298 elf->e_type = ET_CORE;
Roland McGrath3aba4812008-01-30 13:31:44 +01001299 elf->e_machine = machine;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001300 elf->e_version = EV_CURRENT;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001301 elf->e_phoff = sizeof(struct elfhdr);
Roland McGrath3aba4812008-01-30 13:31:44 +01001302 elf->e_flags = flags;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001303 elf->e_ehsize = sizeof(struct elfhdr);
1304 elf->e_phentsize = sizeof(struct elf_phdr);
1305 elf->e_phnum = segs;
Cyrill Gorcunov6970c8e2008-04-29 01:01:18 -07001306
Linus Torvalds1da177e2005-04-16 15:20:36 -07001307 return;
1308}
1309
Andrew Morton8d6b5eee2006-09-25 23:32:04 -07001310static void fill_elf_note_phdr(struct elf_phdr *phdr, int sz, loff_t offset)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001311{
1312 phdr->p_type = PT_NOTE;
1313 phdr->p_offset = offset;
1314 phdr->p_vaddr = 0;
1315 phdr->p_paddr = 0;
1316 phdr->p_filesz = sz;
1317 phdr->p_memsz = 0;
1318 phdr->p_flags = 0;
1319 phdr->p_align = 0;
1320 return;
1321}
1322
1323static void fill_note(struct memelfnote *note, const char *name, int type,
1324 unsigned int sz, void *data)
1325{
1326 note->name = name;
1327 note->type = type;
1328 note->datasz = sz;
1329 note->data = data;
1330 return;
1331}
1332
1333/*
Jesper Juhlf4e5cc22006-06-23 02:05:35 -07001334 * fill up all the fields in prstatus from the given task struct, except
1335 * registers which need to be filled up separately.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001336 */
1337static void fill_prstatus(struct elf_prstatus *prstatus,
Jesper Juhlf4e5cc22006-06-23 02:05:35 -07001338 struct task_struct *p, long signr)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001339{
1340 prstatus->pr_info.si_signo = prstatus->pr_cursig = signr;
1341 prstatus->pr_sigpend = p->pending.signal.sig[0];
1342 prstatus->pr_sighold = p->blocked.sig[0];
Oleg Nesterov3b34fc52009-06-17 16:27:38 -07001343 rcu_read_lock();
1344 prstatus->pr_ppid = task_pid_vnr(rcu_dereference(p->real_parent));
1345 rcu_read_unlock();
Pavel Emelyanovb4888932007-10-18 23:40:14 -07001346 prstatus->pr_pid = task_pid_vnr(p);
Pavel Emelyanovb4888932007-10-18 23:40:14 -07001347 prstatus->pr_pgrp = task_pgrp_vnr(p);
1348 prstatus->pr_sid = task_session_vnr(p);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001349 if (thread_group_leader(p)) {
Frank Mayharf06febc2008-09-12 09:54:39 -07001350 struct task_cputime cputime;
1351
Linus Torvalds1da177e2005-04-16 15:20:36 -07001352 /*
Frank Mayharf06febc2008-09-12 09:54:39 -07001353 * This is the record for the group leader. It shows the
1354 * group-wide total, not its individual thread total.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001355 */
Frank Mayharf06febc2008-09-12 09:54:39 -07001356 thread_group_cputime(p, &cputime);
1357 cputime_to_timeval(cputime.utime, &prstatus->pr_utime);
1358 cputime_to_timeval(cputime.stime, &prstatus->pr_stime);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001359 } else {
1360 cputime_to_timeval(p->utime, &prstatus->pr_utime);
1361 cputime_to_timeval(p->stime, &prstatus->pr_stime);
1362 }
1363 cputime_to_timeval(p->signal->cutime, &prstatus->pr_cutime);
1364 cputime_to_timeval(p->signal->cstime, &prstatus->pr_cstime);
1365}
1366
1367static int fill_psinfo(struct elf_prpsinfo *psinfo, struct task_struct *p,
1368 struct mm_struct *mm)
1369{
David Howellsc69e8d92008-11-14 10:39:19 +11001370 const struct cred *cred;
Greg Kroah-Hartmana84a5052005-05-11 00:10:44 -07001371 unsigned int i, len;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001372
1373 /* first copy the parameters from user space */
1374 memset(psinfo, 0, sizeof(struct elf_prpsinfo));
1375
1376 len = mm->arg_end - mm->arg_start;
1377 if (len >= ELF_PRARGSZ)
1378 len = ELF_PRARGSZ-1;
1379 if (copy_from_user(&psinfo->pr_psargs,
1380 (const char __user *)mm->arg_start, len))
1381 return -EFAULT;
1382 for(i = 0; i < len; i++)
1383 if (psinfo->pr_psargs[i] == 0)
1384 psinfo->pr_psargs[i] = ' ';
1385 psinfo->pr_psargs[len] = 0;
1386
Oleg Nesterov3b34fc52009-06-17 16:27:38 -07001387 rcu_read_lock();
1388 psinfo->pr_ppid = task_pid_vnr(rcu_dereference(p->real_parent));
1389 rcu_read_unlock();
Pavel Emelyanovb4888932007-10-18 23:40:14 -07001390 psinfo->pr_pid = task_pid_vnr(p);
Pavel Emelyanovb4888932007-10-18 23:40:14 -07001391 psinfo->pr_pgrp = task_pgrp_vnr(p);
1392 psinfo->pr_sid = task_session_vnr(p);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001393
1394 i = p->state ? ffz(~p->state) + 1 : 0;
1395 psinfo->pr_state = i;
Carsten Otte55148542006-03-25 03:08:22 -08001396 psinfo->pr_sname = (i > 5) ? '.' : "RSDTZW"[i];
Linus Torvalds1da177e2005-04-16 15:20:36 -07001397 psinfo->pr_zomb = psinfo->pr_sname == 'Z';
1398 psinfo->pr_nice = task_nice(p);
1399 psinfo->pr_flag = p->flags;
David Howellsc69e8d92008-11-14 10:39:19 +11001400 rcu_read_lock();
1401 cred = __task_cred(p);
1402 SET_UID(psinfo->pr_uid, cred->uid);
1403 SET_GID(psinfo->pr_gid, cred->gid);
1404 rcu_read_unlock();
Linus Torvalds1da177e2005-04-16 15:20:36 -07001405 strncpy(psinfo->pr_fname, p->comm, sizeof(psinfo->pr_fname));
1406
1407 return 0;
1408}
1409
Roland McGrath3aba4812008-01-30 13:31:44 +01001410static void fill_auxv_note(struct memelfnote *note, struct mm_struct *mm)
1411{
1412 elf_addr_t *auxv = (elf_addr_t *) mm->saved_auxv;
1413 int i = 0;
1414 do
1415 i += 2;
1416 while (auxv[i - 2] != AT_NULL);
1417 fill_note(note, "CORE", NT_AUXV, i * sizeof(elf_addr_t), auxv);
1418}
1419
Roland McGrath4206d3a2008-01-30 13:31:45 +01001420#ifdef CORE_DUMP_USE_REGSET
1421#include <linux/regset.h>
1422
1423struct elf_thread_core_info {
1424 struct elf_thread_core_info *next;
1425 struct task_struct *task;
1426 struct elf_prstatus prstatus;
1427 struct memelfnote notes[0];
1428};
1429
1430struct elf_note_info {
1431 struct elf_thread_core_info *thread;
1432 struct memelfnote psinfo;
1433 struct memelfnote auxv;
1434 size_t size;
1435 int thread_notes;
1436};
1437
Roland McGrathd31472b2008-03-04 14:28:30 -08001438/*
1439 * When a regset has a writeback hook, we call it on each thread before
1440 * dumping user memory. On register window machines, this makes sure the
1441 * user memory backing the register data is up to date before we read it.
1442 */
1443static void do_thread_regset_writeback(struct task_struct *task,
1444 const struct user_regset *regset)
1445{
1446 if (regset->writeback)
1447 regset->writeback(task, regset, 1);
1448}
1449
Roland McGrath4206d3a2008-01-30 13:31:45 +01001450static int fill_thread_core_info(struct elf_thread_core_info *t,
1451 const struct user_regset_view *view,
1452 long signr, size_t *total)
1453{
1454 unsigned int i;
1455
1456 /*
1457 * NT_PRSTATUS is the one special case, because the regset data
1458 * goes into the pr_reg field inside the note contents, rather
1459 * than being the whole note contents. We fill the reset in here.
1460 * We assume that regset 0 is NT_PRSTATUS.
1461 */
1462 fill_prstatus(&t->prstatus, t->task, signr);
1463 (void) view->regsets[0].get(t->task, &view->regsets[0],
1464 0, sizeof(t->prstatus.pr_reg),
1465 &t->prstatus.pr_reg, NULL);
1466
1467 fill_note(&t->notes[0], "CORE", NT_PRSTATUS,
1468 sizeof(t->prstatus), &t->prstatus);
1469 *total += notesize(&t->notes[0]);
1470
Roland McGrathd31472b2008-03-04 14:28:30 -08001471 do_thread_regset_writeback(t->task, &view->regsets[0]);
1472
Roland McGrath4206d3a2008-01-30 13:31:45 +01001473 /*
1474 * Each other regset might generate a note too. For each regset
1475 * that has no core_note_type or is inactive, we leave t->notes[i]
1476 * all zero and we'll know to skip writing it later.
1477 */
1478 for (i = 1; i < view->n; ++i) {
1479 const struct user_regset *regset = &view->regsets[i];
Roland McGrathd31472b2008-03-04 14:28:30 -08001480 do_thread_regset_writeback(t->task, regset);
Roland McGrath4206d3a2008-01-30 13:31:45 +01001481 if (regset->core_note_type &&
1482 (!regset->active || regset->active(t->task, regset))) {
1483 int ret;
1484 size_t size = regset->n * regset->size;
1485 void *data = kmalloc(size, GFP_KERNEL);
1486 if (unlikely(!data))
1487 return 0;
1488 ret = regset->get(t->task, regset,
1489 0, size, data, NULL);
1490 if (unlikely(ret))
1491 kfree(data);
1492 else {
1493 if (regset->core_note_type != NT_PRFPREG)
1494 fill_note(&t->notes[i], "LINUX",
1495 regset->core_note_type,
1496 size, data);
1497 else {
1498 t->prstatus.pr_fpvalid = 1;
1499 fill_note(&t->notes[i], "CORE",
1500 NT_PRFPREG, size, data);
1501 }
1502 *total += notesize(&t->notes[i]);
1503 }
1504 }
1505 }
1506
1507 return 1;
1508}
1509
1510static int fill_note_info(struct elfhdr *elf, int phdrs,
1511 struct elf_note_info *info,
1512 long signr, struct pt_regs *regs)
1513{
1514 struct task_struct *dump_task = current;
1515 const struct user_regset_view *view = task_user_regset_view(dump_task);
1516 struct elf_thread_core_info *t;
1517 struct elf_prpsinfo *psinfo;
Oleg Nesterov83914442008-07-25 01:47:45 -07001518 struct core_thread *ct;
Roland McGrath4206d3a2008-01-30 13:31:45 +01001519 unsigned int i;
1520
1521 info->size = 0;
1522 info->thread = NULL;
1523
1524 psinfo = kmalloc(sizeof(*psinfo), GFP_KERNEL);
Roland McGrath4206d3a2008-01-30 13:31:45 +01001525 if (psinfo == NULL)
1526 return 0;
1527
Amerigo Wange2dbe122009-07-01 01:06:26 -04001528 fill_note(&info->psinfo, "CORE", NT_PRPSINFO, sizeof(*psinfo), psinfo);
1529
Roland McGrath4206d3a2008-01-30 13:31:45 +01001530 /*
1531 * Figure out how many notes we're going to need for each thread.
1532 */
1533 info->thread_notes = 0;
1534 for (i = 0; i < view->n; ++i)
1535 if (view->regsets[i].core_note_type != 0)
1536 ++info->thread_notes;
1537
1538 /*
1539 * Sanity check. We rely on regset 0 being in NT_PRSTATUS,
1540 * since it is our one special case.
1541 */
1542 if (unlikely(info->thread_notes == 0) ||
1543 unlikely(view->regsets[0].core_note_type != NT_PRSTATUS)) {
1544 WARN_ON(1);
1545 return 0;
1546 }
1547
1548 /*
1549 * Initialize the ELF file header.
1550 */
1551 fill_elf_header(elf, phdrs,
1552 view->e_machine, view->e_flags, view->ei_osabi);
1553
1554 /*
1555 * Allocate a structure for each thread.
1556 */
Oleg Nesterov83914442008-07-25 01:47:45 -07001557 for (ct = &dump_task->mm->core_state->dumper; ct; ct = ct->next) {
1558 t = kzalloc(offsetof(struct elf_thread_core_info,
1559 notes[info->thread_notes]),
1560 GFP_KERNEL);
1561 if (unlikely(!t))
1562 return 0;
Oleg Nesterov24d52882008-07-25 01:47:40 -07001563
Oleg Nesterov83914442008-07-25 01:47:45 -07001564 t->task = ct->task;
1565 if (ct->task == dump_task || !info->thread) {
1566 t->next = info->thread;
1567 info->thread = t;
1568 } else {
1569 /*
1570 * Make sure to keep the original task at
1571 * the head of the list.
1572 */
1573 t->next = info->thread->next;
1574 info->thread->next = t;
Roland McGrath4206d3a2008-01-30 13:31:45 +01001575 }
Oleg Nesterov83914442008-07-25 01:47:45 -07001576 }
Roland McGrath4206d3a2008-01-30 13:31:45 +01001577
1578 /*
1579 * Now fill in each thread's information.
1580 */
1581 for (t = info->thread; t != NULL; t = t->next)
1582 if (!fill_thread_core_info(t, view, signr, &info->size))
1583 return 0;
1584
1585 /*
1586 * Fill in the two process-wide notes.
1587 */
1588 fill_psinfo(psinfo, dump_task->group_leader, dump_task->mm);
1589 info->size += notesize(&info->psinfo);
1590
1591 fill_auxv_note(&info->auxv, current->mm);
1592 info->size += notesize(&info->auxv);
1593
1594 return 1;
1595}
1596
1597static size_t get_note_info_size(struct elf_note_info *info)
1598{
1599 return info->size;
1600}
1601
1602/*
1603 * Write all the notes for each thread. When writing the first thread, the
1604 * process-wide notes are interleaved after the first thread-specific note.
1605 */
1606static int write_note_info(struct elf_note_info *info,
1607 struct file *file, loff_t *foffset)
1608{
1609 bool first = 1;
1610 struct elf_thread_core_info *t = info->thread;
1611
1612 do {
1613 int i;
1614
1615 if (!writenote(&t->notes[0], file, foffset))
1616 return 0;
1617
1618 if (first && !writenote(&info->psinfo, file, foffset))
1619 return 0;
1620 if (first && !writenote(&info->auxv, file, foffset))
1621 return 0;
1622
1623 for (i = 1; i < info->thread_notes; ++i)
1624 if (t->notes[i].data &&
1625 !writenote(&t->notes[i], file, foffset))
1626 return 0;
1627
1628 first = 0;
1629 t = t->next;
1630 } while (t);
1631
1632 return 1;
1633}
1634
1635static void free_note_info(struct elf_note_info *info)
1636{
1637 struct elf_thread_core_info *threads = info->thread;
1638 while (threads) {
1639 unsigned int i;
1640 struct elf_thread_core_info *t = threads;
1641 threads = t->next;
1642 WARN_ON(t->notes[0].data && t->notes[0].data != &t->prstatus);
1643 for (i = 1; i < info->thread_notes; ++i)
1644 kfree(t->notes[i].data);
1645 kfree(t);
1646 }
1647 kfree(info->psinfo.data);
1648}
1649
1650#else
1651
Linus Torvalds1da177e2005-04-16 15:20:36 -07001652/* Here is the structure in which status of each thread is captured. */
1653struct elf_thread_status
1654{
1655 struct list_head list;
1656 struct elf_prstatus prstatus; /* NT_PRSTATUS */
1657 elf_fpregset_t fpu; /* NT_PRFPREG */
1658 struct task_struct *thread;
1659#ifdef ELF_CORE_COPY_XFPREGS
Mark Nelson5b20cd82007-10-16 23:25:39 -07001660 elf_fpxregset_t xfpu; /* ELF_CORE_XFPREG_TYPE */
Linus Torvalds1da177e2005-04-16 15:20:36 -07001661#endif
1662 struct memelfnote notes[3];
1663 int num_notes;
1664};
1665
1666/*
1667 * In order to add the specific thread information for the elf file format,
Jesper Juhlf4e5cc22006-06-23 02:05:35 -07001668 * we need to keep a linked list of every threads pr_status and then create
1669 * a single section for them in the final core file.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001670 */
1671static int elf_dump_thread_status(long signr, struct elf_thread_status *t)
1672{
1673 int sz = 0;
1674 struct task_struct *p = t->thread;
1675 t->num_notes = 0;
1676
1677 fill_prstatus(&t->prstatus, p, signr);
1678 elf_core_copy_task_regs(p, &t->prstatus.pr_reg);
1679
Jesper Juhlf4e5cc22006-06-23 02:05:35 -07001680 fill_note(&t->notes[0], "CORE", NT_PRSTATUS, sizeof(t->prstatus),
1681 &(t->prstatus));
Linus Torvalds1da177e2005-04-16 15:20:36 -07001682 t->num_notes++;
1683 sz += notesize(&t->notes[0]);
1684
Jesper Juhlf4e5cc22006-06-23 02:05:35 -07001685 if ((t->prstatus.pr_fpvalid = elf_core_copy_task_fpregs(p, NULL,
1686 &t->fpu))) {
1687 fill_note(&t->notes[1], "CORE", NT_PRFPREG, sizeof(t->fpu),
1688 &(t->fpu));
Linus Torvalds1da177e2005-04-16 15:20:36 -07001689 t->num_notes++;
1690 sz += notesize(&t->notes[1]);
1691 }
1692
1693#ifdef ELF_CORE_COPY_XFPREGS
1694 if (elf_core_copy_task_xfpregs(p, &t->xfpu)) {
Mark Nelson5b20cd82007-10-16 23:25:39 -07001695 fill_note(&t->notes[2], "LINUX", ELF_CORE_XFPREG_TYPE,
1696 sizeof(t->xfpu), &t->xfpu);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001697 t->num_notes++;
1698 sz += notesize(&t->notes[2]);
1699 }
1700#endif
1701 return sz;
1702}
1703
Roland McGrath3aba4812008-01-30 13:31:44 +01001704struct elf_note_info {
1705 struct memelfnote *notes;
1706 struct elf_prstatus *prstatus; /* NT_PRSTATUS */
1707 struct elf_prpsinfo *psinfo; /* NT_PRPSINFO */
1708 struct list_head thread_list;
1709 elf_fpregset_t *fpu;
1710#ifdef ELF_CORE_COPY_XFPREGS
1711 elf_fpxregset_t *xfpu;
1712#endif
1713 int thread_status_size;
1714 int numnote;
1715};
1716
1717static int fill_note_info(struct elfhdr *elf, int phdrs,
1718 struct elf_note_info *info,
1719 long signr, struct pt_regs *regs)
1720{
1721#define NUM_NOTES 6
1722 struct list_head *t;
Roland McGrath3aba4812008-01-30 13:31:44 +01001723
1724 info->notes = NULL;
1725 info->prstatus = NULL;
1726 info->psinfo = NULL;
1727 info->fpu = NULL;
1728#ifdef ELF_CORE_COPY_XFPREGS
1729 info->xfpu = NULL;
1730#endif
1731 INIT_LIST_HEAD(&info->thread_list);
1732
1733 info->notes = kmalloc(NUM_NOTES * sizeof(struct memelfnote),
1734 GFP_KERNEL);
1735 if (!info->notes)
1736 return 0;
1737 info->psinfo = kmalloc(sizeof(*info->psinfo), GFP_KERNEL);
1738 if (!info->psinfo)
1739 return 0;
1740 info->prstatus = kmalloc(sizeof(*info->prstatus), GFP_KERNEL);
1741 if (!info->prstatus)
1742 return 0;
1743 info->fpu = kmalloc(sizeof(*info->fpu), GFP_KERNEL);
1744 if (!info->fpu)
1745 return 0;
1746#ifdef ELF_CORE_COPY_XFPREGS
1747 info->xfpu = kmalloc(sizeof(*info->xfpu), GFP_KERNEL);
1748 if (!info->xfpu)
1749 return 0;
1750#endif
1751
1752 info->thread_status_size = 0;
1753 if (signr) {
Oleg Nesterov83914442008-07-25 01:47:45 -07001754 struct core_thread *ct;
WANG Cong4220b7f2008-04-29 01:01:18 -07001755 struct elf_thread_status *ets;
Oleg Nesterov24d52882008-07-25 01:47:40 -07001756
Oleg Nesterov83914442008-07-25 01:47:45 -07001757 for (ct = current->mm->core_state->dumper.next;
1758 ct; ct = ct->next) {
1759 ets = kzalloc(sizeof(*ets), GFP_KERNEL);
1760 if (!ets)
1761 return 0;
1762
1763 ets->thread = ct->task;
1764 list_add(&ets->list, &info->thread_list);
1765 }
1766
Roland McGrath3aba4812008-01-30 13:31:44 +01001767 list_for_each(t, &info->thread_list) {
Roland McGrath3aba4812008-01-30 13:31:44 +01001768 int sz;
1769
WANG Cong4220b7f2008-04-29 01:01:18 -07001770 ets = list_entry(t, struct elf_thread_status, list);
1771 sz = elf_dump_thread_status(signr, ets);
Roland McGrath3aba4812008-01-30 13:31:44 +01001772 info->thread_status_size += sz;
1773 }
1774 }
1775 /* now collect the dump for the current */
1776 memset(info->prstatus, 0, sizeof(*info->prstatus));
1777 fill_prstatus(info->prstatus, current, signr);
1778 elf_core_copy_regs(&info->prstatus->pr_reg, regs);
1779
1780 /* Set up header */
1781 fill_elf_header(elf, phdrs, ELF_ARCH, ELF_CORE_EFLAGS, ELF_OSABI);
1782
1783 /*
1784 * Set up the notes in similar form to SVR4 core dumps made
1785 * with info from their /proc.
1786 */
1787
1788 fill_note(info->notes + 0, "CORE", NT_PRSTATUS,
1789 sizeof(*info->prstatus), info->prstatus);
1790 fill_psinfo(info->psinfo, current->group_leader, current->mm);
1791 fill_note(info->notes + 1, "CORE", NT_PRPSINFO,
1792 sizeof(*info->psinfo), info->psinfo);
1793
1794 info->numnote = 2;
1795
1796 fill_auxv_note(&info->notes[info->numnote++], current->mm);
1797
1798 /* Try to dump the FPU. */
1799 info->prstatus->pr_fpvalid = elf_core_copy_task_fpregs(current, regs,
1800 info->fpu);
1801 if (info->prstatus->pr_fpvalid)
1802 fill_note(info->notes + info->numnote++,
1803 "CORE", NT_PRFPREG, sizeof(*info->fpu), info->fpu);
1804#ifdef ELF_CORE_COPY_XFPREGS
1805 if (elf_core_copy_task_xfpregs(current, info->xfpu))
1806 fill_note(info->notes + info->numnote++,
1807 "LINUX", ELF_CORE_XFPREG_TYPE,
1808 sizeof(*info->xfpu), info->xfpu);
1809#endif
1810
1811 return 1;
1812
1813#undef NUM_NOTES
1814}
1815
1816static size_t get_note_info_size(struct elf_note_info *info)
1817{
1818 int sz = 0;
1819 int i;
1820
1821 for (i = 0; i < info->numnote; i++)
1822 sz += notesize(info->notes + i);
1823
1824 sz += info->thread_status_size;
1825
1826 return sz;
1827}
1828
1829static int write_note_info(struct elf_note_info *info,
1830 struct file *file, loff_t *foffset)
1831{
1832 int i;
1833 struct list_head *t;
1834
1835 for (i = 0; i < info->numnote; i++)
1836 if (!writenote(info->notes + i, file, foffset))
1837 return 0;
1838
1839 /* write out the thread status notes section */
1840 list_for_each(t, &info->thread_list) {
1841 struct elf_thread_status *tmp =
1842 list_entry(t, struct elf_thread_status, list);
1843
1844 for (i = 0; i < tmp->num_notes; i++)
1845 if (!writenote(&tmp->notes[i], file, foffset))
1846 return 0;
1847 }
1848
1849 return 1;
1850}
1851
1852static void free_note_info(struct elf_note_info *info)
1853{
1854 while (!list_empty(&info->thread_list)) {
1855 struct list_head *tmp = info->thread_list.next;
1856 list_del(tmp);
1857 kfree(list_entry(tmp, struct elf_thread_status, list));
1858 }
1859
1860 kfree(info->prstatus);
1861 kfree(info->psinfo);
1862 kfree(info->notes);
1863 kfree(info->fpu);
1864#ifdef ELF_CORE_COPY_XFPREGS
1865 kfree(info->xfpu);
1866#endif
1867}
1868
Roland McGrath4206d3a2008-01-30 13:31:45 +01001869#endif
1870
Roland McGrathf47aef52007-01-26 00:56:49 -08001871static struct vm_area_struct *first_vma(struct task_struct *tsk,
1872 struct vm_area_struct *gate_vma)
1873{
1874 struct vm_area_struct *ret = tsk->mm->mmap;
1875
1876 if (ret)
1877 return ret;
1878 return gate_vma;
1879}
1880/*
1881 * Helper function for iterating across a vma list. It ensures that the caller
1882 * will visit `gate_vma' prior to terminating the search.
1883 */
1884static struct vm_area_struct *next_vma(struct vm_area_struct *this_vma,
1885 struct vm_area_struct *gate_vma)
1886{
1887 struct vm_area_struct *ret;
1888
1889 ret = this_vma->vm_next;
1890 if (ret)
1891 return ret;
1892 if (this_vma == gate_vma)
1893 return NULL;
1894 return gate_vma;
1895}
1896
Linus Torvalds1da177e2005-04-16 15:20:36 -07001897/*
1898 * Actual dumper
1899 *
1900 * This is a two-pass process; first we find the offsets of the bits,
1901 * and then they are actually written out. If we run out of core limit
1902 * we just truncate.
1903 */
Neil Horman7dc0b222007-10-16 23:26:34 -07001904static int elf_core_dump(long signr, struct pt_regs *regs, struct file *file, unsigned long limit)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001905{
Linus Torvalds1da177e2005-04-16 15:20:36 -07001906 int has_dumped = 0;
1907 mm_segment_t fs;
1908 int segs;
1909 size_t size = 0;
Roland McGrathf47aef52007-01-26 00:56:49 -08001910 struct vm_area_struct *vma, *gate_vma;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001911 struct elfhdr *elf = NULL;
Andi Kleend025c9d2006-09-30 23:29:28 -07001912 loff_t offset = 0, dataoff, foffset;
Kawai, Hidehiroa1b59e82007-07-19 01:48:29 -07001913 unsigned long mm_flags;
Roland McGrath3aba4812008-01-30 13:31:44 +01001914 struct elf_note_info info;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001915
1916 /*
1917 * We no longer stop all VM operations.
1918 *
Jesper Juhlf4e5cc22006-06-23 02:05:35 -07001919 * This is because those proceses that could possibly change map_count
1920 * or the mmap / vma pages are now blocked in do_exit on current
1921 * finishing this core dump.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001922 *
1923 * Only ptrace can touch these memory addresses, but it doesn't change
Jesper Juhlf4e5cc22006-06-23 02:05:35 -07001924 * the map_count or the pages allocated. So no possibility of crashing
Linus Torvalds1da177e2005-04-16 15:20:36 -07001925 * exists while dumping the mm->vm_next areas to the core file.
1926 */
1927
1928 /* alloc memory for large data structures: too large to be on stack */
1929 elf = kmalloc(sizeof(*elf), GFP_KERNEL);
1930 if (!elf)
WANG Cong5f719552008-05-06 12:45:35 +08001931 goto out;
KAMEZAWA Hiroyuki341c87b2009-06-30 11:41:23 -07001932 /*
1933 * The number of segs are recored into ELF header as 16bit value.
1934 * Please check DEFAULT_MAX_MAP_COUNT definition when you modify here.
1935 */
Linus Torvalds1da177e2005-04-16 15:20:36 -07001936 segs = current->mm->map_count;
1937#ifdef ELF_CORE_EXTRA_PHDRS
1938 segs += ELF_CORE_EXTRA_PHDRS;
1939#endif
1940
Roland McGrathf47aef52007-01-26 00:56:49 -08001941 gate_vma = get_gate_vma(current);
1942 if (gate_vma != NULL)
1943 segs++;
1944
Roland McGrath3aba4812008-01-30 13:31:44 +01001945 /*
1946 * Collect all the non-memory information about the process for the
1947 * notes. This also sets up the file header.
1948 */
1949 if (!fill_note_info(elf, segs + 1, /* including notes section */
1950 &info, signr, regs))
1951 goto cleanup;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001952
1953 has_dumped = 1;
1954 current->flags |= PF_DUMPCORE;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001955
1956 fs = get_fs();
1957 set_fs(KERNEL_DS);
1958
1959 DUMP_WRITE(elf, sizeof(*elf));
1960 offset += sizeof(*elf); /* Elf header */
Petr Vandroveca7a0d862006-10-13 18:42:07 +02001961 offset += (segs + 1) * sizeof(struct elf_phdr); /* Program headers */
1962 foffset = offset;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001963
1964 /* Write notes phdr entry */
1965 {
1966 struct elf_phdr phdr;
Roland McGrath3aba4812008-01-30 13:31:44 +01001967 size_t sz = get_note_info_size(&info);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001968
Michael Ellermane5501492007-09-19 14:38:12 +10001969 sz += elf_coredump_extra_notes_size();
Dwayne Grant McConnellbf1ab972006-11-23 00:46:37 +01001970
Linus Torvalds1da177e2005-04-16 15:20:36 -07001971 fill_elf_note_phdr(&phdr, sz, offset);
1972 offset += sz;
1973 DUMP_WRITE(&phdr, sizeof(phdr));
1974 }
1975
Linus Torvalds1da177e2005-04-16 15:20:36 -07001976 dataoff = offset = roundup(offset, ELF_EXEC_PAGESIZE);
1977
Kawai, Hidehiroa1b59e82007-07-19 01:48:29 -07001978 /*
1979 * We must use the same mm->flags while dumping core to avoid
1980 * inconsistency between the program headers and bodies, otherwise an
1981 * unusable core file can be generated.
1982 */
1983 mm_flags = current->mm->flags;
1984
Linus Torvalds1da177e2005-04-16 15:20:36 -07001985 /* Write program headers for segments dump */
Roland McGrathf47aef52007-01-26 00:56:49 -08001986 for (vma = first_vma(current, gate_vma); vma != NULL;
1987 vma = next_vma(vma, gate_vma)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001988 struct elf_phdr phdr;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001989
1990 phdr.p_type = PT_LOAD;
1991 phdr.p_offset = offset;
1992 phdr.p_vaddr = vma->vm_start;
1993 phdr.p_paddr = 0;
Roland McGrath82df3972007-10-16 23:27:02 -07001994 phdr.p_filesz = vma_dump_size(vma, mm_flags);
1995 phdr.p_memsz = vma->vm_end - vma->vm_start;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001996 offset += phdr.p_filesz;
1997 phdr.p_flags = vma->vm_flags & VM_READ ? PF_R : 0;
Jesper Juhlf4e5cc22006-06-23 02:05:35 -07001998 if (vma->vm_flags & VM_WRITE)
1999 phdr.p_flags |= PF_W;
2000 if (vma->vm_flags & VM_EXEC)
2001 phdr.p_flags |= PF_X;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002002 phdr.p_align = ELF_EXEC_PAGESIZE;
2003
2004 DUMP_WRITE(&phdr, sizeof(phdr));
2005 }
2006
2007#ifdef ELF_CORE_WRITE_EXTRA_PHDRS
2008 ELF_CORE_WRITE_EXTRA_PHDRS;
2009#endif
2010
2011 /* write out the notes section */
Roland McGrath3aba4812008-01-30 13:31:44 +01002012 if (!write_note_info(&info, file, &foffset))
2013 goto end_coredump;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002014
Michael Ellermane5501492007-09-19 14:38:12 +10002015 if (elf_coredump_extra_notes_write(file, &foffset))
2016 goto end_coredump;
Dwayne Grant McConnellbf1ab972006-11-23 00:46:37 +01002017
Andi Kleend025c9d2006-09-30 23:29:28 -07002018 /* Align to page */
2019 DUMP_SEEK(dataoff - foffset);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002020
Roland McGrathf47aef52007-01-26 00:56:49 -08002021 for (vma = first_vma(current, gate_vma); vma != NULL;
2022 vma = next_vma(vma, gate_vma)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07002023 unsigned long addr;
Roland McGrath82df3972007-10-16 23:27:02 -07002024 unsigned long end;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002025
Roland McGrath82df3972007-10-16 23:27:02 -07002026 end = vma->vm_start + vma_dump_size(vma, mm_flags);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002027
Roland McGrath82df3972007-10-16 23:27:02 -07002028 for (addr = vma->vm_start; addr < end; addr += PAGE_SIZE) {
Jesper Juhlf4e5cc22006-06-23 02:05:35 -07002029 struct page *page;
WANG Cong4220b7f2008-04-29 01:01:18 -07002030 struct vm_area_struct *tmp_vma;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002031
2032 if (get_user_pages(current, current->mm, addr, 1, 0, 1,
WANG Cong4220b7f2008-04-29 01:01:18 -07002033 &page, &tmp_vma) <= 0) {
Andi Kleend025c9d2006-09-30 23:29:28 -07002034 DUMP_SEEK(PAGE_SIZE);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002035 } else {
Nick Piggin557ed1f2007-10-16 01:24:40 -07002036 if (page == ZERO_PAGE(0)) {
Brian Pomerantz03221702007-04-01 23:49:41 -07002037 if (!dump_seek(file, PAGE_SIZE)) {
2038 page_cache_release(page);
2039 goto end_coredump;
2040 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07002041 } else {
2042 void *kaddr;
WANG Cong4220b7f2008-04-29 01:01:18 -07002043 flush_cache_page(tmp_vma, addr,
Jesper Juhlf4e5cc22006-06-23 02:05:35 -07002044 page_to_pfn(page));
Linus Torvalds1da177e2005-04-16 15:20:36 -07002045 kaddr = kmap(page);
2046 if ((size += PAGE_SIZE) > limit ||
2047 !dump_write(file, kaddr,
2048 PAGE_SIZE)) {
2049 kunmap(page);
2050 page_cache_release(page);
2051 goto end_coredump;
2052 }
2053 kunmap(page);
2054 }
2055 page_cache_release(page);
2056 }
2057 }
2058 }
2059
2060#ifdef ELF_CORE_WRITE_EXTRA_DATA
2061 ELF_CORE_WRITE_EXTRA_DATA;
2062#endif
2063
Linus Torvalds1da177e2005-04-16 15:20:36 -07002064end_coredump:
2065 set_fs(fs);
2066
2067cleanup:
Roland McGrath3aba4812008-01-30 13:31:44 +01002068 free_note_info(&info);
WANG Cong5f719552008-05-06 12:45:35 +08002069 kfree(elf);
2070out:
Linus Torvalds1da177e2005-04-16 15:20:36 -07002071 return has_dumped;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002072}
2073
2074#endif /* USE_ELF_CORE_DUMP */
2075
2076static int __init init_elf_binfmt(void)
2077{
2078 return register_binfmt(&elf_format);
2079}
2080
2081static void __exit exit_elf_binfmt(void)
2082{
2083 /* Remove the COFF and ELF loaders. */
2084 unregister_binfmt(&elf_format);
2085}
2086
2087core_initcall(init_elf_binfmt);
2088module_exit(exit_elf_binfmt);
2089MODULE_LICENSE("GPL");