blob: bcb884e2d613e76d94570dd81b99ba27e3906a66 [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>
Daisuke HATAYAMA088e7af2010-03-05 13:44:06 -080034#include <linux/coredump.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070035#include <asm/uaccess.h>
36#include <asm/param.h>
37#include <asm/page.h>
38
Jesper Juhlf4e5cc22006-06-23 02:05:35 -070039static int load_elf_binary(struct linux_binprm *bprm, struct pt_regs *regs);
40static int load_elf_library(struct file *);
Andrew Mortonbb1ad822008-01-30 13:31:07 +010041static unsigned long elf_map(struct file *, unsigned long, struct elf_phdr *,
42 int, int, unsigned long);
Linus Torvalds1da177e2005-04-16 15:20:36 -070043
Linus Torvalds1da177e2005-04-16 15:20:36 -070044/*
45 * If we don't support core dumping, then supply a NULL so we
46 * don't even try.
47 */
Christoph Hellwig698ba7b2009-12-15 16:47:37 -080048#ifdef CONFIG_ELF_CORE
Masami Hiramatsuf6151df2009-12-17 15:27:16 -080049static int elf_core_dump(struct coredump_params *cprm);
Linus Torvalds1da177e2005-04-16 15:20:36 -070050#else
51#define elf_core_dump NULL
52#endif
53
54#if ELF_EXEC_PAGESIZE > PAGE_SIZE
Jesper Juhlf4e5cc22006-06-23 02:05:35 -070055#define ELF_MIN_ALIGN ELF_EXEC_PAGESIZE
Linus Torvalds1da177e2005-04-16 15:20:36 -070056#else
Jesper Juhlf4e5cc22006-06-23 02:05:35 -070057#define ELF_MIN_ALIGN PAGE_SIZE
Linus Torvalds1da177e2005-04-16 15:20:36 -070058#endif
59
60#ifndef ELF_CORE_EFLAGS
61#define ELF_CORE_EFLAGS 0
62#endif
63
64#define ELF_PAGESTART(_v) ((_v) & ~(unsigned long)(ELF_MIN_ALIGN-1))
65#define ELF_PAGEOFFSET(_v) ((_v) & (ELF_MIN_ALIGN-1))
66#define ELF_PAGEALIGN(_v) (((_v) + ELF_MIN_ALIGN - 1) & ~(ELF_MIN_ALIGN - 1))
67
68static struct linux_binfmt elf_format = {
Mikael Petterssonf670d0e2011-01-12 17:00:02 -080069 .module = THIS_MODULE,
70 .load_binary = load_elf_binary,
71 .load_shlib = load_elf_library,
72 .core_dump = elf_core_dump,
73 .min_coredump = ELF_EXEC_PAGESIZE,
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
Linus Torvalds1da177e2005-04-16 15:20:36 -0700318static unsigned long elf_map(struct file *filep, unsigned long addr,
Jiri Kosinacc503c12008-01-30 13:31:07 +0100319 struct elf_phdr *eppnt, int prot, int type,
320 unsigned long total_size)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700321{
322 unsigned long map_addr;
Jiri Kosinacc503c12008-01-30 13:31:07 +0100323 unsigned long size = eppnt->p_filesz + ELF_PAGEOFFSET(eppnt->p_vaddr);
324 unsigned long off = eppnt->p_offset - ELF_PAGEOFFSET(eppnt->p_vaddr);
325 addr = ELF_PAGESTART(addr);
326 size = ELF_PAGEALIGN(size);
Jan Kratochvil60bfba72007-07-15 23:40:06 -0700327
Andrew Mortond4e3cc32007-07-21 04:37:32 -0700328 /* mmap() will return -EINVAL if given a zero size, but a
329 * segment with zero filesize is perfectly valid */
Jiri Kosinacc503c12008-01-30 13:31:07 +0100330 if (!size)
331 return addr;
332
333 down_write(&current->mm->mmap_sem);
334 /*
335 * total_size is the size of the ELF (interpreter) image.
336 * The _first_ mmap needs to know the full size, otherwise
337 * randomization might put this image into an overlapping
338 * position with the ELF binary image. (since size < total_size)
339 * So we first map the 'big' image - and unmap the remainder at
340 * the end. (which unmap is needed for ELF images with holes.)
341 */
342 if (total_size) {
343 total_size = ELF_PAGEALIGN(total_size);
344 map_addr = do_mmap(filep, addr, total_size, prot, type, off);
345 if (!BAD_ADDR(map_addr))
346 do_munmap(current->mm, map_addr+size, total_size-size);
347 } else
348 map_addr = do_mmap(filep, addr, size, prot, type, off);
349
Linus Torvalds1da177e2005-04-16 15:20:36 -0700350 up_write(&current->mm->mmap_sem);
351 return(map_addr);
352}
353
Jiri Kosinacc503c12008-01-30 13:31:07 +0100354static unsigned long total_mapping_size(struct elf_phdr *cmds, int nr)
355{
356 int i, first_idx = -1, last_idx = -1;
357
358 for (i = 0; i < nr; i++) {
359 if (cmds[i].p_type == PT_LOAD) {
360 last_idx = i;
361 if (first_idx == -1)
362 first_idx = i;
363 }
364 }
365 if (first_idx == -1)
366 return 0;
367
368 return cmds[last_idx].p_vaddr + cmds[last_idx].p_memsz -
369 ELF_PAGESTART(cmds[first_idx].p_vaddr);
370}
371
372
Linus Torvalds1da177e2005-04-16 15:20:36 -0700373/* This is much more generalized than the library routine read function,
374 so we keep this separate. Technically the library read function
375 is only provided so that we can read a.out libraries that have
376 an ELF header */
377
Jesper Juhlf4e5cc22006-06-23 02:05:35 -0700378static unsigned long load_elf_interp(struct elfhdr *interp_elf_ex,
Jiri Kosinacc503c12008-01-30 13:31:07 +0100379 struct file *interpreter, unsigned long *interp_map_addr,
380 unsigned long no_base)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700381{
382 struct elf_phdr *elf_phdata;
383 struct elf_phdr *eppnt;
384 unsigned long load_addr = 0;
385 int load_addr_set = 0;
386 unsigned long last_bss = 0, elf_bss = 0;
387 unsigned long error = ~0UL;
Jiri Kosinacc503c12008-01-30 13:31:07 +0100388 unsigned long total_size;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700389 int retval, i, size;
390
391 /* First of all, some simple consistency checks */
392 if (interp_elf_ex->e_type != ET_EXEC &&
393 interp_elf_ex->e_type != ET_DYN)
394 goto out;
395 if (!elf_check_arch(interp_elf_ex))
396 goto out;
397 if (!interpreter->f_op || !interpreter->f_op->mmap)
398 goto out;
399
400 /*
401 * If the size of this structure has changed, then punt, since
402 * we will be doing the wrong thing.
403 */
404 if (interp_elf_ex->e_phentsize != sizeof(struct elf_phdr))
405 goto out;
406 if (interp_elf_ex->e_phnum < 1 ||
407 interp_elf_ex->e_phnum > 65536U / sizeof(struct elf_phdr))
408 goto out;
409
410 /* Now read in all of the header information */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700411 size = sizeof(struct elf_phdr) * interp_elf_ex->e_phnum;
412 if (size > ELF_MIN_ALIGN)
413 goto out;
Jesper Juhlf4e5cc22006-06-23 02:05:35 -0700414 elf_phdata = kmalloc(size, GFP_KERNEL);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700415 if (!elf_phdata)
416 goto out;
417
Jesper Juhlf4e5cc22006-06-23 02:05:35 -0700418 retval = kernel_read(interpreter, interp_elf_ex->e_phoff,
Mikael Petterssonf670d0e2011-01-12 17:00:02 -0800419 (char *)elf_phdata, size);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700420 error = -EIO;
421 if (retval != size) {
422 if (retval < 0)
423 error = retval;
424 goto out_close;
425 }
426
Jiri Kosinacc503c12008-01-30 13:31:07 +0100427 total_size = total_mapping_size(elf_phdata, interp_elf_ex->e_phnum);
428 if (!total_size) {
429 error = -EINVAL;
430 goto out_close;
431 }
432
Linus Torvalds1da177e2005-04-16 15:20:36 -0700433 eppnt = elf_phdata;
Jesper Juhlf4e5cc22006-06-23 02:05:35 -0700434 for (i = 0; i < interp_elf_ex->e_phnum; i++, eppnt++) {
435 if (eppnt->p_type == PT_LOAD) {
436 int elf_type = MAP_PRIVATE | MAP_DENYWRITE;
437 int elf_prot = 0;
438 unsigned long vaddr = 0;
439 unsigned long k, map_addr;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700440
Jesper Juhlf4e5cc22006-06-23 02:05:35 -0700441 if (eppnt->p_flags & PF_R)
442 elf_prot = PROT_READ;
443 if (eppnt->p_flags & PF_W)
444 elf_prot |= PROT_WRITE;
445 if (eppnt->p_flags & PF_X)
446 elf_prot |= PROT_EXEC;
447 vaddr = eppnt->p_vaddr;
448 if (interp_elf_ex->e_type == ET_EXEC || load_addr_set)
449 elf_type |= MAP_FIXED;
Jiri Kosinacc503c12008-01-30 13:31:07 +0100450 else if (no_base && interp_elf_ex->e_type == ET_DYN)
451 load_addr = -vaddr;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700452
Jesper Juhlf4e5cc22006-06-23 02:05:35 -0700453 map_addr = elf_map(interpreter, load_addr + vaddr,
Andrew Mortonbb1ad822008-01-30 13:31:07 +0100454 eppnt, elf_prot, elf_type, total_size);
Jiri Kosinacc503c12008-01-30 13:31:07 +0100455 total_size = 0;
456 if (!*interp_map_addr)
457 *interp_map_addr = map_addr;
Jesper Juhlf4e5cc22006-06-23 02:05:35 -0700458 error = map_addr;
459 if (BAD_ADDR(map_addr))
460 goto out_close;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700461
Jesper Juhlf4e5cc22006-06-23 02:05:35 -0700462 if (!load_addr_set &&
463 interp_elf_ex->e_type == ET_DYN) {
464 load_addr = map_addr - ELF_PAGESTART(vaddr);
465 load_addr_set = 1;
466 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700467
Jesper Juhlf4e5cc22006-06-23 02:05:35 -0700468 /*
469 * Check to see if the section's size will overflow the
470 * allowed task size. Note that p_filesz must always be
471 * <= p_memsize so it's only necessary to check p_memsz.
472 */
473 k = load_addr + eppnt->p_vaddr;
Chuck Ebbertce510592006-07-03 00:24:14 -0700474 if (BAD_ADDR(k) ||
Jesper Juhlf4e5cc22006-06-23 02:05:35 -0700475 eppnt->p_filesz > eppnt->p_memsz ||
476 eppnt->p_memsz > TASK_SIZE ||
477 TASK_SIZE - eppnt->p_memsz < k) {
478 error = -ENOMEM;
479 goto out_close;
480 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700481
Jesper Juhlf4e5cc22006-06-23 02:05:35 -0700482 /*
483 * Find the end of the file mapping for this phdr, and
484 * keep track of the largest address we see for this.
485 */
486 k = load_addr + eppnt->p_vaddr + eppnt->p_filesz;
487 if (k > elf_bss)
488 elf_bss = k;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700489
Jesper Juhlf4e5cc22006-06-23 02:05:35 -0700490 /*
491 * Do the same thing for the memory mapping - between
492 * elf_bss and last_bss is the bss section.
493 */
494 k = load_addr + eppnt->p_memsz + eppnt->p_vaddr;
495 if (k > last_bss)
496 last_bss = k;
497 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700498 }
499
Linus Torvalds1da177e2005-04-16 15:20:36 -0700500 if (last_bss > elf_bss) {
Roland McGrath752015d2009-09-08 19:49:40 -0700501 /*
502 * Now fill out the bss section. First pad the last page up
503 * to the page boundary, and then perform a mmap to make sure
504 * that there are zero-mapped pages up to and including the
505 * last bss page.
506 */
507 if (padzero(elf_bss)) {
508 error = -EFAULT;
509 goto out_close;
510 }
511
512 /* What we have mapped so far */
513 elf_bss = ELF_PAGESTART(elf_bss + ELF_MIN_ALIGN - 1);
514
515 /* Map the last of the bss segment */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700516 down_write(&current->mm->mmap_sem);
517 error = do_brk(elf_bss, last_bss - elf_bss);
518 up_write(&current->mm->mmap_sem);
519 if (BAD_ADDR(error))
520 goto out_close;
521 }
522
Jiri Kosinacc503c12008-01-30 13:31:07 +0100523 error = load_addr;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700524
525out_close:
526 kfree(elf_phdata);
527out:
528 return error;
529}
530
Linus Torvalds1da177e2005-04-16 15:20:36 -0700531/*
532 * These are the functions used to load ELF style executables and shared
533 * libraries. There is no binary dependent code anywhere else.
534 */
535
536#define INTERPRETER_NONE 0
Linus Torvalds1da177e2005-04-16 15:20:36 -0700537#define INTERPRETER_ELF 2
538
Andi Kleen913bd902006-03-25 16:29:09 +0100539#ifndef STACK_RND_MASK
James Bottomleyd1cabd62007-03-16 13:38:35 -0800540#define STACK_RND_MASK (0x7ff >> (PAGE_SHIFT - 12)) /* 8MB of VA */
Andi Kleen913bd902006-03-25 16:29:09 +0100541#endif
Linus Torvalds1da177e2005-04-16 15:20:36 -0700542
543static unsigned long randomize_stack_top(unsigned long stack_top)
544{
545 unsigned int random_variable = 0;
546
Andi Kleenc16b63e2006-09-26 10:52:28 +0200547 if ((current->flags & PF_RANDOMIZE) &&
548 !(current->personality & ADDR_NO_RANDOMIZE)) {
Andi Kleen913bd902006-03-25 16:29:09 +0100549 random_variable = get_random_int() & STACK_RND_MASK;
550 random_variable <<= PAGE_SHIFT;
551 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700552#ifdef CONFIG_STACK_GROWSUP
Andi Kleen913bd902006-03-25 16:29:09 +0100553 return PAGE_ALIGN(stack_top) + random_variable;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700554#else
Andi Kleen913bd902006-03-25 16:29:09 +0100555 return PAGE_ALIGN(stack_top) - random_variable;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700556#endif
557}
558
Jesper Juhlf4e5cc22006-06-23 02:05:35 -0700559static int load_elf_binary(struct linux_binprm *bprm, struct pt_regs *regs)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700560{
561 struct file *interpreter = NULL; /* to shut gcc up */
562 unsigned long load_addr = 0, load_bias = 0;
563 int load_addr_set = 0;
564 char * elf_interpreter = NULL;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700565 unsigned long error;
Jesper Juhlf4e5cc22006-06-23 02:05:35 -0700566 struct elf_phdr *elf_ppnt, *elf_phdata;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700567 unsigned long elf_bss, elf_brk;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700568 int retval, i;
569 unsigned int size;
Jiri Kosinacc503c12008-01-30 13:31:07 +0100570 unsigned long elf_entry;
571 unsigned long interp_load_addr = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700572 unsigned long start_code, end_code, start_data, end_data;
David Daney1a530a62011-03-22 16:34:48 -0700573 unsigned long reloc_func_desc __maybe_unused = 0;
David Rientjes8de61e62006-12-06 20:40:16 -0800574 int executable_stack = EXSTACK_DEFAULT;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700575 unsigned long def_flags = 0;
576 struct {
577 struct elfhdr elf_ex;
578 struct elfhdr interp_elf_ex;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700579 } *loc;
580
581 loc = kmalloc(sizeof(*loc), GFP_KERNEL);
582 if (!loc) {
583 retval = -ENOMEM;
584 goto out_ret;
585 }
586
587 /* Get the exec-header */
Jesper Juhlf4e5cc22006-06-23 02:05:35 -0700588 loc->elf_ex = *((struct elfhdr *)bprm->buf);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700589
590 retval = -ENOEXEC;
591 /* First of all, some simple consistency checks */
592 if (memcmp(loc->elf_ex.e_ident, ELFMAG, SELFMAG) != 0)
593 goto out;
594
595 if (loc->elf_ex.e_type != ET_EXEC && loc->elf_ex.e_type != ET_DYN)
596 goto out;
597 if (!elf_check_arch(&loc->elf_ex))
598 goto out;
Mikael Petterssonf670d0e2011-01-12 17:00:02 -0800599 if (!bprm->file->f_op || !bprm->file->f_op->mmap)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700600 goto out;
601
602 /* Now read in all of the header information */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700603 if (loc->elf_ex.e_phentsize != sizeof(struct elf_phdr))
604 goto out;
605 if (loc->elf_ex.e_phnum < 1 ||
606 loc->elf_ex.e_phnum > 65536U / sizeof(struct elf_phdr))
607 goto out;
608 size = loc->elf_ex.e_phnum * sizeof(struct elf_phdr);
609 retval = -ENOMEM;
Jesper Juhlf4e5cc22006-06-23 02:05:35 -0700610 elf_phdata = kmalloc(size, GFP_KERNEL);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700611 if (!elf_phdata)
612 goto out;
613
Jesper Juhlf4e5cc22006-06-23 02:05:35 -0700614 retval = kernel_read(bprm->file, loc->elf_ex.e_phoff,
615 (char *)elf_phdata, size);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700616 if (retval != size) {
617 if (retval >= 0)
618 retval = -EIO;
619 goto out_free_ph;
620 }
621
Linus Torvalds1da177e2005-04-16 15:20:36 -0700622 elf_ppnt = elf_phdata;
623 elf_bss = 0;
624 elf_brk = 0;
625
626 start_code = ~0UL;
627 end_code = 0;
628 start_data = 0;
629 end_data = 0;
630
631 for (i = 0; i < loc->elf_ex.e_phnum; i++) {
632 if (elf_ppnt->p_type == PT_INTERP) {
633 /* This is the program interpreter used for
634 * shared libraries - for now assume that this
635 * is an a.out format binary
636 */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700637 retval = -ENOEXEC;
638 if (elf_ppnt->p_filesz > PATH_MAX ||
639 elf_ppnt->p_filesz < 2)
Al Viroe7b9b552009-03-29 16:31:16 -0400640 goto out_free_ph;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700641
642 retval = -ENOMEM;
Jesper Juhl792db3a2006-01-09 20:54:45 -0800643 elf_interpreter = kmalloc(elf_ppnt->p_filesz,
Jesper Juhlf4e5cc22006-06-23 02:05:35 -0700644 GFP_KERNEL);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700645 if (!elf_interpreter)
Al Viroe7b9b552009-03-29 16:31:16 -0400646 goto out_free_ph;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700647
648 retval = kernel_read(bprm->file, elf_ppnt->p_offset,
Jesper Juhlf4e5cc22006-06-23 02:05:35 -0700649 elf_interpreter,
650 elf_ppnt->p_filesz);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700651 if (retval != elf_ppnt->p_filesz) {
652 if (retval >= 0)
653 retval = -EIO;
654 goto out_free_interp;
655 }
656 /* make sure path is NULL terminated */
657 retval = -ENOEXEC;
658 if (elf_interpreter[elf_ppnt->p_filesz - 1] != '\0')
659 goto out_free_interp;
660
Linus Torvalds1da177e2005-04-16 15:20:36 -0700661 interpreter = open_exec(elf_interpreter);
662 retval = PTR_ERR(interpreter);
663 if (IS_ERR(interpreter))
664 goto out_free_interp;
Alexey Dobriyan1fb84492007-01-26 00:57:16 -0800665
666 /*
667 * If the binary is not readable then enforce
668 * mm->dumpable = 0 regardless of the interpreter's
669 * permissions.
670 */
Al Viro1b5d7832011-06-19 12:49:47 -0400671 would_dump(bprm, interpreter);
Alexey Dobriyan1fb84492007-01-26 00:57:16 -0800672
Jesper Juhlf4e5cc22006-06-23 02:05:35 -0700673 retval = kernel_read(interpreter, 0, bprm->buf,
674 BINPRM_BUF_SIZE);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700675 if (retval != BINPRM_BUF_SIZE) {
676 if (retval >= 0)
677 retval = -EIO;
678 goto out_free_dentry;
679 }
680
681 /* Get the exec headers */
Jesper Juhlf4e5cc22006-06-23 02:05:35 -0700682 loc->interp_elf_ex = *((struct elfhdr *)bprm->buf);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700683 break;
684 }
685 elf_ppnt++;
686 }
687
688 elf_ppnt = elf_phdata;
689 for (i = 0; i < loc->elf_ex.e_phnum; i++, elf_ppnt++)
690 if (elf_ppnt->p_type == PT_GNU_STACK) {
691 if (elf_ppnt->p_flags & PF_X)
692 executable_stack = EXSTACK_ENABLE_X;
693 else
694 executable_stack = EXSTACK_DISABLE_X;
695 break;
696 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700697
698 /* Some simple consistency checks for the interpreter */
699 if (elf_interpreter) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700700 retval = -ELIBBAD;
Andi Kleend20894a2008-02-08 04:21:54 -0800701 /* Not an ELF interpreter */
702 if (memcmp(loc->interp_elf_ex.e_ident, ELFMAG, SELFMAG) != 0)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700703 goto out_free_dentry;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700704 /* Verify the interpreter has a valid arch */
Andi Kleend20894a2008-02-08 04:21:54 -0800705 if (!elf_check_arch(&loc->interp_elf_ex))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700706 goto out_free_dentry;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700707 }
708
Linus Torvalds1da177e2005-04-16 15:20:36 -0700709 /* Flush all traces of the currently running executable */
710 retval = flush_old_exec(bprm);
711 if (retval)
712 goto out_free_dentry;
713
Linus Torvalds1da177e2005-04-16 15:20:36 -0700714 /* OK, This is the point of no return */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700715 current->flags &= ~PF_FORKNOEXEC;
716 current->mm->def_flags = def_flags;
717
718 /* Do this immediately, since STACK_TOP as used in setup_arg_pages
719 may depend on the personality. */
Martin Schwidefsky0b592682008-10-16 15:39:57 +0200720 SET_PERSONALITY(loc->elf_ex);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700721 if (elf_read_implies_exec(loc->elf_ex, executable_stack))
722 current->personality |= READ_IMPLIES_EXEC;
723
Jesper Juhlf4e5cc22006-06-23 02:05:35 -0700724 if (!(current->personality & ADDR_NO_RANDOMIZE) && randomize_va_space)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700725 current->flags |= PF_RANDOMIZE;
Linus Torvalds221af7f2010-01-28 22:14:42 -0800726
727 setup_new_exec(bprm);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700728
729 /* Do this so that we can load the interpreter, if need be. We will
730 change some of these later */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700731 current->mm->free_area_cache = current->mm->mmap_base;
Wolfgang Wander1363c3c2005-06-21 17:14:49 -0700732 current->mm->cached_hole_size = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700733 retval = setup_arg_pages(bprm, randomize_stack_top(STACK_TOP),
734 executable_stack);
735 if (retval < 0) {
736 send_sig(SIGKILL, current, 0);
737 goto out_free_dentry;
738 }
739
Linus Torvalds1da177e2005-04-16 15:20:36 -0700740 current->mm->start_stack = bprm->p;
741
André Goddard Rosaaf901ca2009-11-14 13:09:05 -0200742 /* Now we do a little grungy work by mmapping the ELF image into
Jiri Kosinacc503c12008-01-30 13:31:07 +0100743 the correct location in memory. */
Jesper Juhlf4e5cc22006-06-23 02:05:35 -0700744 for(i = 0, elf_ppnt = elf_phdata;
745 i < loc->elf_ex.e_phnum; i++, elf_ppnt++) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700746 int elf_prot = 0, elf_flags;
747 unsigned long k, vaddr;
748
749 if (elf_ppnt->p_type != PT_LOAD)
750 continue;
751
752 if (unlikely (elf_brk > elf_bss)) {
753 unsigned long nbyte;
754
755 /* There was a PT_LOAD segment with p_memsz > p_filesz
756 before this one. Map anonymous pages, if needed,
757 and clear the area. */
Mikael Petterssonf670d0e2011-01-12 17:00:02 -0800758 retval = set_brk(elf_bss + load_bias,
759 elf_brk + load_bias);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700760 if (retval) {
761 send_sig(SIGKILL, current, 0);
762 goto out_free_dentry;
763 }
764 nbyte = ELF_PAGEOFFSET(elf_bss);
765 if (nbyte) {
766 nbyte = ELF_MIN_ALIGN - nbyte;
767 if (nbyte > elf_brk - elf_bss)
768 nbyte = elf_brk - elf_bss;
769 if (clear_user((void __user *)elf_bss +
770 load_bias, nbyte)) {
771 /*
772 * This bss-zeroing can fail if the ELF
Jesper Juhlf4e5cc22006-06-23 02:05:35 -0700773 * file specifies odd protections. So
Linus Torvalds1da177e2005-04-16 15:20:36 -0700774 * we don't check the return value
775 */
776 }
777 }
778 }
779
Jesper Juhlf4e5cc22006-06-23 02:05:35 -0700780 if (elf_ppnt->p_flags & PF_R)
781 elf_prot |= PROT_READ;
782 if (elf_ppnt->p_flags & PF_W)
783 elf_prot |= PROT_WRITE;
784 if (elf_ppnt->p_flags & PF_X)
785 elf_prot |= PROT_EXEC;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700786
Jesper Juhlf4e5cc22006-06-23 02:05:35 -0700787 elf_flags = MAP_PRIVATE | MAP_DENYWRITE | MAP_EXECUTABLE;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700788
789 vaddr = elf_ppnt->p_vaddr;
790 if (loc->elf_ex.e_type == ET_EXEC || load_addr_set) {
791 elf_flags |= MAP_FIXED;
792 } else if (loc->elf_ex.e_type == ET_DYN) {
Jesper Juhlf4e5cc22006-06-23 02:05:35 -0700793 /* Try and get dynamic programs out of the way of the
794 * default mmap base, as well as whatever program they
795 * might try to exec. This is because the brk will
796 * follow the loader, and is not movable. */
David Daneye39f5602012-01-10 15:10:21 -0800797#ifdef CONFIG_ARCH_BINFMT_ELF_RANDOMIZE_PIE
Jiri Kosinaa3defbe2011-11-02 13:37:41 -0700798 /* Memory randomization might have been switched off
799 * in runtime via sysctl.
800 * If that is the case, retain the original non-zero
801 * load_bias value in order to establish proper
802 * non-randomized mappings.
803 */
804 if (current->flags & PF_RANDOMIZE)
805 load_bias = 0;
806 else
807 load_bias = ELF_PAGESTART(ELF_ET_DYN_BASE - vaddr);
Jiri Kosinacc503c12008-01-30 13:31:07 +0100808#else
Linus Torvalds90cb28e2007-01-06 13:28:21 -0800809 load_bias = ELF_PAGESTART(ELF_ET_DYN_BASE - vaddr);
Jiri Kosinacc503c12008-01-30 13:31:07 +0100810#endif
Linus Torvalds1da177e2005-04-16 15:20:36 -0700811 }
812
Jesper Juhlf4e5cc22006-06-23 02:05:35 -0700813 error = elf_map(bprm->file, load_bias + vaddr, elf_ppnt,
Andrew Mortonbb1ad822008-01-30 13:31:07 +0100814 elf_prot, elf_flags, 0);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700815 if (BAD_ADDR(error)) {
816 send_sig(SIGKILL, current, 0);
Alexey Kuznetsovb140f252007-05-08 00:31:57 -0700817 retval = IS_ERR((void *)error) ?
818 PTR_ERR((void*)error) : -EINVAL;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700819 goto out_free_dentry;
820 }
821
822 if (!load_addr_set) {
823 load_addr_set = 1;
824 load_addr = (elf_ppnt->p_vaddr - elf_ppnt->p_offset);
825 if (loc->elf_ex.e_type == ET_DYN) {
826 load_bias += error -
827 ELF_PAGESTART(load_bias + vaddr);
828 load_addr += load_bias;
829 reloc_func_desc = load_bias;
830 }
831 }
832 k = elf_ppnt->p_vaddr;
Jesper Juhlf4e5cc22006-06-23 02:05:35 -0700833 if (k < start_code)
834 start_code = k;
835 if (start_data < k)
836 start_data = k;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700837
838 /*
839 * Check to see if the section's size will overflow the
840 * allowed task size. Note that p_filesz must always be
841 * <= p_memsz so it is only necessary to check p_memsz.
842 */
Chuck Ebbertce510592006-07-03 00:24:14 -0700843 if (BAD_ADDR(k) || elf_ppnt->p_filesz > elf_ppnt->p_memsz ||
Linus Torvalds1da177e2005-04-16 15:20:36 -0700844 elf_ppnt->p_memsz > TASK_SIZE ||
845 TASK_SIZE - elf_ppnt->p_memsz < k) {
Jesper Juhlf4e5cc22006-06-23 02:05:35 -0700846 /* set_brk can never work. Avoid overflows. */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700847 send_sig(SIGKILL, current, 0);
Alexey Kuznetsovb140f252007-05-08 00:31:57 -0700848 retval = -EINVAL;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700849 goto out_free_dentry;
850 }
851
852 k = elf_ppnt->p_vaddr + elf_ppnt->p_filesz;
853
854 if (k > elf_bss)
855 elf_bss = k;
856 if ((elf_ppnt->p_flags & PF_X) && end_code < k)
857 end_code = k;
858 if (end_data < k)
859 end_data = k;
860 k = elf_ppnt->p_vaddr + elf_ppnt->p_memsz;
861 if (k > elf_brk)
862 elf_brk = k;
863 }
864
865 loc->elf_ex.e_entry += load_bias;
866 elf_bss += load_bias;
867 elf_brk += load_bias;
868 start_code += load_bias;
869 end_code += load_bias;
870 start_data += load_bias;
871 end_data += load_bias;
872
873 /* Calling set_brk effectively mmaps the pages that we need
874 * for the bss and break sections. We must do this before
875 * mapping in the interpreter, to make sure it doesn't wind
876 * up getting placed where the bss needs to go.
877 */
878 retval = set_brk(elf_bss, elf_brk);
879 if (retval) {
880 send_sig(SIGKILL, current, 0);
881 goto out_free_dentry;
882 }
akpm@osdl.org6de50512005-10-11 08:29:08 -0700883 if (likely(elf_bss != elf_brk) && unlikely(padzero(elf_bss))) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700884 send_sig(SIGSEGV, current, 0);
885 retval = -EFAULT; /* Nobody gets to see this, but.. */
886 goto out_free_dentry;
887 }
888
889 if (elf_interpreter) {
Andi Kleend20894a2008-02-08 04:21:54 -0800890 unsigned long uninitialized_var(interp_map_addr);
Jiri Kosinacc503c12008-01-30 13:31:07 +0100891
Andi Kleend20894a2008-02-08 04:21:54 -0800892 elf_entry = load_elf_interp(&loc->interp_elf_ex,
893 interpreter,
894 &interp_map_addr,
895 load_bias);
896 if (!IS_ERR((void *)elf_entry)) {
897 /*
898 * load_elf_interp() returns relocation
899 * adjustment
900 */
901 interp_load_addr = elf_entry;
902 elf_entry += loc->interp_elf_ex.e_entry;
Jiri Kosinacc503c12008-01-30 13:31:07 +0100903 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700904 if (BAD_ADDR(elf_entry)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700905 force_sig(SIGSEGV, current);
Chuck Ebbertce510592006-07-03 00:24:14 -0700906 retval = IS_ERR((void *)elf_entry) ?
907 (int)elf_entry : -EINVAL;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700908 goto out_free_dentry;
909 }
910 reloc_func_desc = interp_load_addr;
911
912 allow_write_access(interpreter);
913 fput(interpreter);
914 kfree(elf_interpreter);
915 } else {
916 elf_entry = loc->elf_ex.e_entry;
Suresh Siddha5342fba2006-02-26 04:18:28 +0100917 if (BAD_ADDR(elf_entry)) {
Chuck Ebbertce510592006-07-03 00:24:14 -0700918 force_sig(SIGSEGV, current);
919 retval = -EINVAL;
Suresh Siddha5342fba2006-02-26 04:18:28 +0100920 goto out_free_dentry;
921 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700922 }
923
924 kfree(elf_phdata);
925
Linus Torvalds1da177e2005-04-16 15:20:36 -0700926 set_binfmt(&elf_format);
927
Benjamin Herrenschmidt547ee842005-04-16 15:24:35 -0700928#ifdef ARCH_HAS_SETUP_ADDITIONAL_PAGES
Martin Schwidefskyfc5243d2008-12-25 13:38:35 +0100929 retval = arch_setup_additional_pages(bprm, !!elf_interpreter);
Benjamin Herrenschmidt547ee842005-04-16 15:24:35 -0700930 if (retval < 0) {
931 send_sig(SIGKILL, current, 0);
Roland McGrath18c8baf2005-04-28 15:17:19 -0700932 goto out;
Benjamin Herrenschmidt547ee842005-04-16 15:24:35 -0700933 }
934#endif /* ARCH_HAS_SETUP_ADDITIONAL_PAGES */
935
David Howellsa6f76f22008-11-14 10:39:24 +1100936 install_exec_creds(bprm);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700937 current->flags &= ~PF_FORKNOEXEC;
Ollie Wildb6a2fea2007-07-19 01:48:16 -0700938 retval = create_elf_tables(bprm, &loc->elf_ex,
Jesper Juhlf4e5cc22006-06-23 02:05:35 -0700939 load_addr, interp_load_addr);
Ollie Wildb6a2fea2007-07-19 01:48:16 -0700940 if (retval < 0) {
941 send_sig(SIGKILL, current, 0);
942 goto out;
943 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700944 /* N.B. passed_fileno might not be initialized? */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700945 current->mm->end_code = end_code;
946 current->mm->start_code = start_code;
947 current->mm->start_data = start_data;
948 current->mm->end_data = end_data;
949 current->mm->start_stack = bprm->p;
950
Jiri Kosinac1d171a2008-01-30 13:30:40 +0100951#ifdef arch_randomize_brk
Jiri Kosina4471a672011-04-14 15:22:09 -0700952 if ((current->flags & PF_RANDOMIZE) && (randomize_va_space > 1)) {
Jiri Kosinac1d171a2008-01-30 13:30:40 +0100953 current->mm->brk = current->mm->start_brk =
954 arch_randomize_brk(current->mm);
Jiri Kosina4471a672011-04-14 15:22:09 -0700955#ifdef CONFIG_COMPAT_BRK
956 current->brk_randomized = 1;
957#endif
958 }
Jiri Kosinac1d171a2008-01-30 13:30:40 +0100959#endif
960
Linus Torvalds1da177e2005-04-16 15:20:36 -0700961 if (current->personality & MMAP_PAGE_ZERO) {
962 /* Why this, you ask??? Well SVr4 maps page 0 as read-only,
963 and some applications "depend" upon this behavior.
964 Since we do not have the power to recompile these, we
Jesper Juhlf4e5cc22006-06-23 02:05:35 -0700965 emulate the SVr4 behavior. Sigh. */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700966 down_write(&current->mm->mmap_sem);
967 error = do_mmap(NULL, 0, PAGE_SIZE, PROT_READ | PROT_EXEC,
968 MAP_FIXED | MAP_PRIVATE, 0);
969 up_write(&current->mm->mmap_sem);
970 }
971
972#ifdef ELF_PLAT_INIT
973 /*
974 * The ABI may specify that certain registers be set up in special
975 * ways (on i386 %edx is the address of a DT_FINI function, for
976 * example. In addition, it may also specify (eg, PowerPC64 ELF)
977 * that the e_entry field is the address of the function descriptor
978 * for the startup routine, rather than the address of the startup
979 * routine itself. This macro performs whatever initialization to
980 * the regs structure is required as well as any relocations to the
981 * function descriptor entries when executing dynamically links apps.
982 */
983 ELF_PLAT_INIT(regs, reloc_func_desc);
984#endif
985
986 start_thread(regs, elf_entry, bprm->p);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700987 retval = 0;
988out:
989 kfree(loc);
990out_ret:
991 return retval;
992
993 /* error cleanup */
994out_free_dentry:
995 allow_write_access(interpreter);
996 if (interpreter)
997 fput(interpreter);
998out_free_interp:
Jesper Juhlf99d49a2005-11-07 01:01:34 -0800999 kfree(elf_interpreter);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001000out_free_ph:
1001 kfree(elf_phdata);
1002 goto out;
1003}
1004
1005/* This is really simpleminded and specialized - we are loading an
1006 a.out library that is given an ELF header. */
Linus Torvalds1da177e2005-04-16 15:20:36 -07001007static int load_elf_library(struct file *file)
1008{
1009 struct elf_phdr *elf_phdata;
1010 struct elf_phdr *eppnt;
1011 unsigned long elf_bss, bss, len;
1012 int retval, error, i, j;
1013 struct elfhdr elf_ex;
1014
1015 error = -ENOEXEC;
Jesper Juhlf4e5cc22006-06-23 02:05:35 -07001016 retval = kernel_read(file, 0, (char *)&elf_ex, sizeof(elf_ex));
Linus Torvalds1da177e2005-04-16 15:20:36 -07001017 if (retval != sizeof(elf_ex))
1018 goto out;
1019
1020 if (memcmp(elf_ex.e_ident, ELFMAG, SELFMAG) != 0)
1021 goto out;
1022
1023 /* First of all, some simple consistency checks */
1024 if (elf_ex.e_type != ET_EXEC || elf_ex.e_phnum > 2 ||
Jesper Juhlf4e5cc22006-06-23 02:05:35 -07001025 !elf_check_arch(&elf_ex) || !file->f_op || !file->f_op->mmap)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001026 goto out;
1027
1028 /* Now read in all of the header information */
1029
1030 j = sizeof(struct elf_phdr) * elf_ex.e_phnum;
1031 /* j < ELF_MIN_ALIGN because elf_ex.e_phnum <= 2 */
1032
1033 error = -ENOMEM;
1034 elf_phdata = kmalloc(j, GFP_KERNEL);
1035 if (!elf_phdata)
1036 goto out;
1037
1038 eppnt = elf_phdata;
1039 error = -ENOEXEC;
1040 retval = kernel_read(file, elf_ex.e_phoff, (char *)eppnt, j);
1041 if (retval != j)
1042 goto out_free_ph;
1043
1044 for (j = 0, i = 0; i<elf_ex.e_phnum; i++)
1045 if ((eppnt + i)->p_type == PT_LOAD)
1046 j++;
1047 if (j != 1)
1048 goto out_free_ph;
1049
1050 while (eppnt->p_type != PT_LOAD)
1051 eppnt++;
1052
1053 /* Now use mmap to map the library into memory. */
1054 down_write(&current->mm->mmap_sem);
1055 error = do_mmap(file,
1056 ELF_PAGESTART(eppnt->p_vaddr),
1057 (eppnt->p_filesz +
1058 ELF_PAGEOFFSET(eppnt->p_vaddr)),
1059 PROT_READ | PROT_WRITE | PROT_EXEC,
1060 MAP_FIXED | MAP_PRIVATE | MAP_DENYWRITE,
1061 (eppnt->p_offset -
1062 ELF_PAGEOFFSET(eppnt->p_vaddr)));
1063 up_write(&current->mm->mmap_sem);
1064 if (error != ELF_PAGESTART(eppnt->p_vaddr))
1065 goto out_free_ph;
1066
1067 elf_bss = eppnt->p_vaddr + eppnt->p_filesz;
1068 if (padzero(elf_bss)) {
1069 error = -EFAULT;
1070 goto out_free_ph;
1071 }
1072
Jesper Juhlf4e5cc22006-06-23 02:05:35 -07001073 len = ELF_PAGESTART(eppnt->p_filesz + eppnt->p_vaddr +
1074 ELF_MIN_ALIGN - 1);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001075 bss = eppnt->p_memsz + eppnt->p_vaddr;
1076 if (bss > len) {
1077 down_write(&current->mm->mmap_sem);
1078 do_brk(len, bss - len);
1079 up_write(&current->mm->mmap_sem);
1080 }
1081 error = 0;
1082
1083out_free_ph:
1084 kfree(elf_phdata);
1085out:
1086 return error;
1087}
1088
Christoph Hellwig698ba7b2009-12-15 16:47:37 -08001089#ifdef CONFIG_ELF_CORE
Linus Torvalds1da177e2005-04-16 15:20:36 -07001090/*
1091 * ELF core dumper
1092 *
1093 * Modelled on fs/exec.c:aout_core_dump()
1094 * Jeremy Fitzhardinge <jeremy@sw.oz.au>
1095 */
Linus Torvalds1da177e2005-04-16 15:20:36 -07001096
1097/*
Roland McGrath82df3972007-10-16 23:27:02 -07001098 * Decide what to dump of a segment, part, all or none.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001099 */
Roland McGrath82df3972007-10-16 23:27:02 -07001100static unsigned long vma_dump_size(struct vm_area_struct *vma,
1101 unsigned long mm_flags)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001102{
KOSAKI Motohiroe575f112008-10-18 20:27:08 -07001103#define FILTER(type) (mm_flags & (1UL << MMF_DUMP_##type))
1104
Roland McGrathe5b97dd2007-01-26 00:56:48 -08001105 /* The vma can be set up to tell us the answer directly. */
1106 if (vma->vm_flags & VM_ALWAYSDUMP)
Roland McGrath82df3972007-10-16 23:27:02 -07001107 goto whole;
Roland McGrathe5b97dd2007-01-26 00:56:48 -08001108
KOSAKI Motohiroe575f112008-10-18 20:27:08 -07001109 /* Hugetlb memory check */
1110 if (vma->vm_flags & VM_HUGETLB) {
1111 if ((vma->vm_flags & VM_SHARED) && FILTER(HUGETLB_SHARED))
1112 goto whole;
1113 if (!(vma->vm_flags & VM_SHARED) && FILTER(HUGETLB_PRIVATE))
1114 goto whole;
1115 }
1116
Linus Torvalds1da177e2005-04-16 15:20:36 -07001117 /* Do not dump I/O mapped devices or special mappings */
1118 if (vma->vm_flags & (VM_IO | VM_RESERVED))
1119 return 0;
1120
Kawai, Hidehiroa1b59e82007-07-19 01:48:29 -07001121 /* By default, dump shared memory if mapped from an anonymous file. */
1122 if (vma->vm_flags & VM_SHARED) {
Roland McGrath82df3972007-10-16 23:27:02 -07001123 if (vma->vm_file->f_path.dentry->d_inode->i_nlink == 0 ?
1124 FILTER(ANON_SHARED) : FILTER(MAPPED_SHARED))
1125 goto whole;
1126 return 0;
Kawai, Hidehiroa1b59e82007-07-19 01:48:29 -07001127 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001128
Roland McGrath82df3972007-10-16 23:27:02 -07001129 /* Dump segments that have been written to. */
1130 if (vma->anon_vma && FILTER(ANON_PRIVATE))
1131 goto whole;
1132 if (vma->vm_file == NULL)
1133 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001134
Roland McGrath82df3972007-10-16 23:27:02 -07001135 if (FILTER(MAPPED_PRIVATE))
1136 goto whole;
1137
1138 /*
1139 * If this looks like the beginning of a DSO or executable mapping,
1140 * check for an ELF header. If we find one, dump the first page to
1141 * aid in determining what was mapped here.
1142 */
Roland McGrath92dc07b2009-02-06 17:34:07 -08001143 if (FILTER(ELF_HEADERS) &&
1144 vma->vm_pgoff == 0 && (vma->vm_flags & VM_READ)) {
Roland McGrath82df3972007-10-16 23:27:02 -07001145 u32 __user *header = (u32 __user *) vma->vm_start;
1146 u32 word;
Roland McGrath92dc07b2009-02-06 17:34:07 -08001147 mm_segment_t fs = get_fs();
Roland McGrath82df3972007-10-16 23:27:02 -07001148 /*
1149 * Doing it this way gets the constant folded by GCC.
1150 */
1151 union {
1152 u32 cmp;
1153 char elfmag[SELFMAG];
1154 } magic;
1155 BUILD_BUG_ON(SELFMAG != sizeof word);
1156 magic.elfmag[EI_MAG0] = ELFMAG0;
1157 magic.elfmag[EI_MAG1] = ELFMAG1;
1158 magic.elfmag[EI_MAG2] = ELFMAG2;
1159 magic.elfmag[EI_MAG3] = ELFMAG3;
Roland McGrath92dc07b2009-02-06 17:34:07 -08001160 /*
1161 * Switch to the user "segment" for get_user(),
1162 * then put back what elf_core_dump() had in place.
1163 */
1164 set_fs(USER_DS);
1165 if (unlikely(get_user(word, header)))
1166 word = 0;
1167 set_fs(fs);
1168 if (word == magic.cmp)
Roland McGrath82df3972007-10-16 23:27:02 -07001169 return PAGE_SIZE;
1170 }
1171
1172#undef FILTER
1173
1174 return 0;
1175
1176whole:
1177 return vma->vm_end - vma->vm_start;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001178}
1179
Linus Torvalds1da177e2005-04-16 15:20:36 -07001180/* An ELF note in memory */
1181struct memelfnote
1182{
1183 const char *name;
1184 int type;
1185 unsigned int datasz;
1186 void *data;
1187};
1188
1189static int notesize(struct memelfnote *en)
1190{
1191 int sz;
1192
1193 sz = sizeof(struct elf_note);
1194 sz += roundup(strlen(en->name) + 1, 4);
1195 sz += roundup(en->datasz, 4);
1196
1197 return sz;
1198}
1199
Andi Kleend025c9d2006-09-30 23:29:28 -07001200#define DUMP_WRITE(addr, nr, foffset) \
1201 do { if (!dump_write(file, (addr), (nr))) return 0; *foffset += (nr); } while(0)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001202
Andi Kleend025c9d2006-09-30 23:29:28 -07001203static int alignfile(struct file *file, loff_t *foffset)
1204{
Petr Vandroveca7a0d862006-10-13 18:42:07 +02001205 static const char buf[4] = { 0, };
Andi Kleend025c9d2006-09-30 23:29:28 -07001206 DUMP_WRITE(buf, roundup(*foffset, 4) - *foffset, foffset);
1207 return 1;
1208}
1209
1210static int writenote(struct memelfnote *men, struct file *file,
1211 loff_t *foffset)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001212{
1213 struct elf_note en;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001214 en.n_namesz = strlen(men->name) + 1;
1215 en.n_descsz = men->datasz;
1216 en.n_type = men->type;
1217
Andi Kleend025c9d2006-09-30 23:29:28 -07001218 DUMP_WRITE(&en, sizeof(en), foffset);
1219 DUMP_WRITE(men->name, en.n_namesz, foffset);
1220 if (!alignfile(file, foffset))
1221 return 0;
1222 DUMP_WRITE(men->data, men->datasz, foffset);
1223 if (!alignfile(file, foffset))
1224 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001225
1226 return 1;
1227}
1228#undef DUMP_WRITE
Linus Torvalds1da177e2005-04-16 15:20:36 -07001229
Roland McGrath3aba4812008-01-30 13:31:44 +01001230static void fill_elf_header(struct elfhdr *elf, int segs,
1231 u16 machine, u32 flags, u8 osabi)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001232{
Cyrill Gorcunov6970c8e2008-04-29 01:01:18 -07001233 memset(elf, 0, sizeof(*elf));
1234
Linus Torvalds1da177e2005-04-16 15:20:36 -07001235 memcpy(elf->e_ident, ELFMAG, SELFMAG);
1236 elf->e_ident[EI_CLASS] = ELF_CLASS;
1237 elf->e_ident[EI_DATA] = ELF_DATA;
1238 elf->e_ident[EI_VERSION] = EV_CURRENT;
1239 elf->e_ident[EI_OSABI] = ELF_OSABI;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001240
1241 elf->e_type = ET_CORE;
Roland McGrath3aba4812008-01-30 13:31:44 +01001242 elf->e_machine = machine;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001243 elf->e_version = EV_CURRENT;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001244 elf->e_phoff = sizeof(struct elfhdr);
Roland McGrath3aba4812008-01-30 13:31:44 +01001245 elf->e_flags = flags;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001246 elf->e_ehsize = sizeof(struct elfhdr);
1247 elf->e_phentsize = sizeof(struct elf_phdr);
1248 elf->e_phnum = segs;
Cyrill Gorcunov6970c8e2008-04-29 01:01:18 -07001249
Linus Torvalds1da177e2005-04-16 15:20:36 -07001250 return;
1251}
1252
Andrew Morton8d6b5eee2006-09-25 23:32:04 -07001253static void fill_elf_note_phdr(struct elf_phdr *phdr, int sz, loff_t offset)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001254{
1255 phdr->p_type = PT_NOTE;
1256 phdr->p_offset = offset;
1257 phdr->p_vaddr = 0;
1258 phdr->p_paddr = 0;
1259 phdr->p_filesz = sz;
1260 phdr->p_memsz = 0;
1261 phdr->p_flags = 0;
1262 phdr->p_align = 0;
1263 return;
1264}
1265
1266static void fill_note(struct memelfnote *note, const char *name, int type,
1267 unsigned int sz, void *data)
1268{
1269 note->name = name;
1270 note->type = type;
1271 note->datasz = sz;
1272 note->data = data;
1273 return;
1274}
1275
1276/*
Jesper Juhlf4e5cc22006-06-23 02:05:35 -07001277 * fill up all the fields in prstatus from the given task struct, except
1278 * registers which need to be filled up separately.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001279 */
1280static void fill_prstatus(struct elf_prstatus *prstatus,
Jesper Juhlf4e5cc22006-06-23 02:05:35 -07001281 struct task_struct *p, long signr)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001282{
1283 prstatus->pr_info.si_signo = prstatus->pr_cursig = signr;
1284 prstatus->pr_sigpend = p->pending.signal.sig[0];
1285 prstatus->pr_sighold = p->blocked.sig[0];
Oleg Nesterov3b34fc52009-06-17 16:27:38 -07001286 rcu_read_lock();
1287 prstatus->pr_ppid = task_pid_vnr(rcu_dereference(p->real_parent));
1288 rcu_read_unlock();
Pavel Emelyanovb4888932007-10-18 23:40:14 -07001289 prstatus->pr_pid = task_pid_vnr(p);
Pavel Emelyanovb4888932007-10-18 23:40:14 -07001290 prstatus->pr_pgrp = task_pgrp_vnr(p);
1291 prstatus->pr_sid = task_session_vnr(p);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001292 if (thread_group_leader(p)) {
Frank Mayharf06febc2008-09-12 09:54:39 -07001293 struct task_cputime cputime;
1294
Linus Torvalds1da177e2005-04-16 15:20:36 -07001295 /*
Frank Mayharf06febc2008-09-12 09:54:39 -07001296 * This is the record for the group leader. It shows the
1297 * group-wide total, not its individual thread total.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001298 */
Frank Mayharf06febc2008-09-12 09:54:39 -07001299 thread_group_cputime(p, &cputime);
1300 cputime_to_timeval(cputime.utime, &prstatus->pr_utime);
1301 cputime_to_timeval(cputime.stime, &prstatus->pr_stime);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001302 } else {
1303 cputime_to_timeval(p->utime, &prstatus->pr_utime);
1304 cputime_to_timeval(p->stime, &prstatus->pr_stime);
1305 }
1306 cputime_to_timeval(p->signal->cutime, &prstatus->pr_cutime);
1307 cputime_to_timeval(p->signal->cstime, &prstatus->pr_cstime);
1308}
1309
1310static int fill_psinfo(struct elf_prpsinfo *psinfo, struct task_struct *p,
1311 struct mm_struct *mm)
1312{
David Howellsc69e8d92008-11-14 10:39:19 +11001313 const struct cred *cred;
Greg Kroah-Hartmana84a5052005-05-11 00:10:44 -07001314 unsigned int i, len;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001315
1316 /* first copy the parameters from user space */
1317 memset(psinfo, 0, sizeof(struct elf_prpsinfo));
1318
1319 len = mm->arg_end - mm->arg_start;
1320 if (len >= ELF_PRARGSZ)
1321 len = ELF_PRARGSZ-1;
1322 if (copy_from_user(&psinfo->pr_psargs,
1323 (const char __user *)mm->arg_start, len))
1324 return -EFAULT;
1325 for(i = 0; i < len; i++)
1326 if (psinfo->pr_psargs[i] == 0)
1327 psinfo->pr_psargs[i] = ' ';
1328 psinfo->pr_psargs[len] = 0;
1329
Oleg Nesterov3b34fc52009-06-17 16:27:38 -07001330 rcu_read_lock();
1331 psinfo->pr_ppid = task_pid_vnr(rcu_dereference(p->real_parent));
1332 rcu_read_unlock();
Pavel Emelyanovb4888932007-10-18 23:40:14 -07001333 psinfo->pr_pid = task_pid_vnr(p);
Pavel Emelyanovb4888932007-10-18 23:40:14 -07001334 psinfo->pr_pgrp = task_pgrp_vnr(p);
1335 psinfo->pr_sid = task_session_vnr(p);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001336
1337 i = p->state ? ffz(~p->state) + 1 : 0;
1338 psinfo->pr_state = i;
Carsten Otte55148542006-03-25 03:08:22 -08001339 psinfo->pr_sname = (i > 5) ? '.' : "RSDTZW"[i];
Linus Torvalds1da177e2005-04-16 15:20:36 -07001340 psinfo->pr_zomb = psinfo->pr_sname == 'Z';
1341 psinfo->pr_nice = task_nice(p);
1342 psinfo->pr_flag = p->flags;
David Howellsc69e8d92008-11-14 10:39:19 +11001343 rcu_read_lock();
1344 cred = __task_cred(p);
1345 SET_UID(psinfo->pr_uid, cred->uid);
1346 SET_GID(psinfo->pr_gid, cred->gid);
1347 rcu_read_unlock();
Linus Torvalds1da177e2005-04-16 15:20:36 -07001348 strncpy(psinfo->pr_fname, p->comm, sizeof(psinfo->pr_fname));
1349
1350 return 0;
1351}
1352
Roland McGrath3aba4812008-01-30 13:31:44 +01001353static void fill_auxv_note(struct memelfnote *note, struct mm_struct *mm)
1354{
1355 elf_addr_t *auxv = (elf_addr_t *) mm->saved_auxv;
1356 int i = 0;
1357 do
1358 i += 2;
1359 while (auxv[i - 2] != AT_NULL);
1360 fill_note(note, "CORE", NT_AUXV, i * sizeof(elf_addr_t), auxv);
1361}
1362
Roland McGrath4206d3a2008-01-30 13:31:45 +01001363#ifdef CORE_DUMP_USE_REGSET
1364#include <linux/regset.h>
1365
1366struct elf_thread_core_info {
1367 struct elf_thread_core_info *next;
1368 struct task_struct *task;
1369 struct elf_prstatus prstatus;
1370 struct memelfnote notes[0];
1371};
1372
1373struct elf_note_info {
1374 struct elf_thread_core_info *thread;
1375 struct memelfnote psinfo;
1376 struct memelfnote auxv;
1377 size_t size;
1378 int thread_notes;
1379};
1380
Roland McGrathd31472b2008-03-04 14:28:30 -08001381/*
1382 * When a regset has a writeback hook, we call it on each thread before
1383 * dumping user memory. On register window machines, this makes sure the
1384 * user memory backing the register data is up to date before we read it.
1385 */
1386static void do_thread_regset_writeback(struct task_struct *task,
1387 const struct user_regset *regset)
1388{
1389 if (regset->writeback)
1390 regset->writeback(task, regset, 1);
1391}
1392
Roland McGrath4206d3a2008-01-30 13:31:45 +01001393static int fill_thread_core_info(struct elf_thread_core_info *t,
1394 const struct user_regset_view *view,
1395 long signr, size_t *total)
1396{
1397 unsigned int i;
1398
1399 /*
1400 * NT_PRSTATUS is the one special case, because the regset data
1401 * goes into the pr_reg field inside the note contents, rather
1402 * than being the whole note contents. We fill the reset in here.
1403 * We assume that regset 0 is NT_PRSTATUS.
1404 */
1405 fill_prstatus(&t->prstatus, t->task, signr);
1406 (void) view->regsets[0].get(t->task, &view->regsets[0],
1407 0, sizeof(t->prstatus.pr_reg),
1408 &t->prstatus.pr_reg, NULL);
1409
1410 fill_note(&t->notes[0], "CORE", NT_PRSTATUS,
1411 sizeof(t->prstatus), &t->prstatus);
1412 *total += notesize(&t->notes[0]);
1413
Roland McGrathd31472b2008-03-04 14:28:30 -08001414 do_thread_regset_writeback(t->task, &view->regsets[0]);
1415
Roland McGrath4206d3a2008-01-30 13:31:45 +01001416 /*
1417 * Each other regset might generate a note too. For each regset
1418 * that has no core_note_type or is inactive, we leave t->notes[i]
1419 * all zero and we'll know to skip writing it later.
1420 */
1421 for (i = 1; i < view->n; ++i) {
1422 const struct user_regset *regset = &view->regsets[i];
Roland McGrathd31472b2008-03-04 14:28:30 -08001423 do_thread_regset_writeback(t->task, regset);
Roland McGrath4206d3a2008-01-30 13:31:45 +01001424 if (regset->core_note_type &&
1425 (!regset->active || regset->active(t->task, regset))) {
1426 int ret;
1427 size_t size = regset->n * regset->size;
1428 void *data = kmalloc(size, GFP_KERNEL);
1429 if (unlikely(!data))
1430 return 0;
1431 ret = regset->get(t->task, regset,
1432 0, size, data, NULL);
1433 if (unlikely(ret))
1434 kfree(data);
1435 else {
1436 if (regset->core_note_type != NT_PRFPREG)
1437 fill_note(&t->notes[i], "LINUX",
1438 regset->core_note_type,
1439 size, data);
1440 else {
1441 t->prstatus.pr_fpvalid = 1;
1442 fill_note(&t->notes[i], "CORE",
1443 NT_PRFPREG, size, data);
1444 }
1445 *total += notesize(&t->notes[i]);
1446 }
1447 }
1448 }
1449
1450 return 1;
1451}
1452
1453static int fill_note_info(struct elfhdr *elf, int phdrs,
1454 struct elf_note_info *info,
1455 long signr, struct pt_regs *regs)
1456{
1457 struct task_struct *dump_task = current;
1458 const struct user_regset_view *view = task_user_regset_view(dump_task);
1459 struct elf_thread_core_info *t;
1460 struct elf_prpsinfo *psinfo;
Oleg Nesterov83914442008-07-25 01:47:45 -07001461 struct core_thread *ct;
Roland McGrath4206d3a2008-01-30 13:31:45 +01001462 unsigned int i;
1463
1464 info->size = 0;
1465 info->thread = NULL;
1466
1467 psinfo = kmalloc(sizeof(*psinfo), GFP_KERNEL);
Roland McGrath4206d3a2008-01-30 13:31:45 +01001468 if (psinfo == NULL)
1469 return 0;
1470
Amerigo Wange2dbe122009-07-01 01:06:26 -04001471 fill_note(&info->psinfo, "CORE", NT_PRPSINFO, sizeof(*psinfo), psinfo);
1472
Roland McGrath4206d3a2008-01-30 13:31:45 +01001473 /*
1474 * Figure out how many notes we're going to need for each thread.
1475 */
1476 info->thread_notes = 0;
1477 for (i = 0; i < view->n; ++i)
1478 if (view->regsets[i].core_note_type != 0)
1479 ++info->thread_notes;
1480
1481 /*
1482 * Sanity check. We rely on regset 0 being in NT_PRSTATUS,
1483 * since it is our one special case.
1484 */
1485 if (unlikely(info->thread_notes == 0) ||
1486 unlikely(view->regsets[0].core_note_type != NT_PRSTATUS)) {
1487 WARN_ON(1);
1488 return 0;
1489 }
1490
1491 /*
1492 * Initialize the ELF file header.
1493 */
1494 fill_elf_header(elf, phdrs,
1495 view->e_machine, view->e_flags, view->ei_osabi);
1496
1497 /*
1498 * Allocate a structure for each thread.
1499 */
Oleg Nesterov83914442008-07-25 01:47:45 -07001500 for (ct = &dump_task->mm->core_state->dumper; ct; ct = ct->next) {
1501 t = kzalloc(offsetof(struct elf_thread_core_info,
1502 notes[info->thread_notes]),
1503 GFP_KERNEL);
1504 if (unlikely(!t))
1505 return 0;
Oleg Nesterov24d52882008-07-25 01:47:40 -07001506
Oleg Nesterov83914442008-07-25 01:47:45 -07001507 t->task = ct->task;
1508 if (ct->task == dump_task || !info->thread) {
1509 t->next = info->thread;
1510 info->thread = t;
1511 } else {
1512 /*
1513 * Make sure to keep the original task at
1514 * the head of the list.
1515 */
1516 t->next = info->thread->next;
1517 info->thread->next = t;
Roland McGrath4206d3a2008-01-30 13:31:45 +01001518 }
Oleg Nesterov83914442008-07-25 01:47:45 -07001519 }
Roland McGrath4206d3a2008-01-30 13:31:45 +01001520
1521 /*
1522 * Now fill in each thread's information.
1523 */
1524 for (t = info->thread; t != NULL; t = t->next)
1525 if (!fill_thread_core_info(t, view, signr, &info->size))
1526 return 0;
1527
1528 /*
1529 * Fill in the two process-wide notes.
1530 */
1531 fill_psinfo(psinfo, dump_task->group_leader, dump_task->mm);
1532 info->size += notesize(&info->psinfo);
1533
1534 fill_auxv_note(&info->auxv, current->mm);
1535 info->size += notesize(&info->auxv);
1536
1537 return 1;
1538}
1539
1540static size_t get_note_info_size(struct elf_note_info *info)
1541{
1542 return info->size;
1543}
1544
1545/*
1546 * Write all the notes for each thread. When writing the first thread, the
1547 * process-wide notes are interleaved after the first thread-specific note.
1548 */
1549static int write_note_info(struct elf_note_info *info,
1550 struct file *file, loff_t *foffset)
1551{
1552 bool first = 1;
1553 struct elf_thread_core_info *t = info->thread;
1554
1555 do {
1556 int i;
1557
1558 if (!writenote(&t->notes[0], file, foffset))
1559 return 0;
1560
1561 if (first && !writenote(&info->psinfo, file, foffset))
1562 return 0;
1563 if (first && !writenote(&info->auxv, file, foffset))
1564 return 0;
1565
1566 for (i = 1; i < info->thread_notes; ++i)
1567 if (t->notes[i].data &&
1568 !writenote(&t->notes[i], file, foffset))
1569 return 0;
1570
1571 first = 0;
1572 t = t->next;
1573 } while (t);
1574
1575 return 1;
1576}
1577
1578static void free_note_info(struct elf_note_info *info)
1579{
1580 struct elf_thread_core_info *threads = info->thread;
1581 while (threads) {
1582 unsigned int i;
1583 struct elf_thread_core_info *t = threads;
1584 threads = t->next;
1585 WARN_ON(t->notes[0].data && t->notes[0].data != &t->prstatus);
1586 for (i = 1; i < info->thread_notes; ++i)
1587 kfree(t->notes[i].data);
1588 kfree(t);
1589 }
1590 kfree(info->psinfo.data);
1591}
1592
1593#else
1594
Linus Torvalds1da177e2005-04-16 15:20:36 -07001595/* Here is the structure in which status of each thread is captured. */
1596struct elf_thread_status
1597{
1598 struct list_head list;
1599 struct elf_prstatus prstatus; /* NT_PRSTATUS */
1600 elf_fpregset_t fpu; /* NT_PRFPREG */
1601 struct task_struct *thread;
1602#ifdef ELF_CORE_COPY_XFPREGS
Mark Nelson5b20cd82007-10-16 23:25:39 -07001603 elf_fpxregset_t xfpu; /* ELF_CORE_XFPREG_TYPE */
Linus Torvalds1da177e2005-04-16 15:20:36 -07001604#endif
1605 struct memelfnote notes[3];
1606 int num_notes;
1607};
1608
1609/*
1610 * In order to add the specific thread information for the elf file format,
Jesper Juhlf4e5cc22006-06-23 02:05:35 -07001611 * we need to keep a linked list of every threads pr_status and then create
1612 * a single section for them in the final core file.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001613 */
1614static int elf_dump_thread_status(long signr, struct elf_thread_status *t)
1615{
1616 int sz = 0;
1617 struct task_struct *p = t->thread;
1618 t->num_notes = 0;
1619
1620 fill_prstatus(&t->prstatus, p, signr);
1621 elf_core_copy_task_regs(p, &t->prstatus.pr_reg);
1622
Jesper Juhlf4e5cc22006-06-23 02:05:35 -07001623 fill_note(&t->notes[0], "CORE", NT_PRSTATUS, sizeof(t->prstatus),
1624 &(t->prstatus));
Linus Torvalds1da177e2005-04-16 15:20:36 -07001625 t->num_notes++;
1626 sz += notesize(&t->notes[0]);
1627
Jesper Juhlf4e5cc22006-06-23 02:05:35 -07001628 if ((t->prstatus.pr_fpvalid = elf_core_copy_task_fpregs(p, NULL,
1629 &t->fpu))) {
1630 fill_note(&t->notes[1], "CORE", NT_PRFPREG, sizeof(t->fpu),
1631 &(t->fpu));
Linus Torvalds1da177e2005-04-16 15:20:36 -07001632 t->num_notes++;
1633 sz += notesize(&t->notes[1]);
1634 }
1635
1636#ifdef ELF_CORE_COPY_XFPREGS
1637 if (elf_core_copy_task_xfpregs(p, &t->xfpu)) {
Mark Nelson5b20cd82007-10-16 23:25:39 -07001638 fill_note(&t->notes[2], "LINUX", ELF_CORE_XFPREG_TYPE,
1639 sizeof(t->xfpu), &t->xfpu);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001640 t->num_notes++;
1641 sz += notesize(&t->notes[2]);
1642 }
1643#endif
1644 return sz;
1645}
1646
Roland McGrath3aba4812008-01-30 13:31:44 +01001647struct elf_note_info {
1648 struct memelfnote *notes;
1649 struct elf_prstatus *prstatus; /* NT_PRSTATUS */
1650 struct elf_prpsinfo *psinfo; /* NT_PRPSINFO */
1651 struct list_head thread_list;
1652 elf_fpregset_t *fpu;
1653#ifdef ELF_CORE_COPY_XFPREGS
1654 elf_fpxregset_t *xfpu;
1655#endif
1656 int thread_status_size;
1657 int numnote;
1658};
1659
Amerigo Wang0cf062d2009-09-23 15:57:05 -07001660static int elf_note_info_init(struct elf_note_info *info)
Roland McGrath3aba4812008-01-30 13:31:44 +01001661{
Amerigo Wang0cf062d2009-09-23 15:57:05 -07001662 memset(info, 0, sizeof(*info));
Roland McGrath3aba4812008-01-30 13:31:44 +01001663 INIT_LIST_HEAD(&info->thread_list);
1664
Amerigo Wang0cf062d2009-09-23 15:57:05 -07001665 /* Allocate space for six ELF notes */
1666 info->notes = kmalloc(6 * sizeof(struct memelfnote), GFP_KERNEL);
Roland McGrath3aba4812008-01-30 13:31:44 +01001667 if (!info->notes)
1668 return 0;
1669 info->psinfo = kmalloc(sizeof(*info->psinfo), GFP_KERNEL);
1670 if (!info->psinfo)
Amerigo Wang0cf062d2009-09-23 15:57:05 -07001671 goto notes_free;
Roland McGrath3aba4812008-01-30 13:31:44 +01001672 info->prstatus = kmalloc(sizeof(*info->prstatus), GFP_KERNEL);
1673 if (!info->prstatus)
Amerigo Wang0cf062d2009-09-23 15:57:05 -07001674 goto psinfo_free;
Roland McGrath3aba4812008-01-30 13:31:44 +01001675 info->fpu = kmalloc(sizeof(*info->fpu), GFP_KERNEL);
1676 if (!info->fpu)
Amerigo Wang0cf062d2009-09-23 15:57:05 -07001677 goto prstatus_free;
Roland McGrath3aba4812008-01-30 13:31:44 +01001678#ifdef ELF_CORE_COPY_XFPREGS
1679 info->xfpu = kmalloc(sizeof(*info->xfpu), GFP_KERNEL);
1680 if (!info->xfpu)
Amerigo Wang0cf062d2009-09-23 15:57:05 -07001681 goto fpu_free;
Roland McGrath3aba4812008-01-30 13:31:44 +01001682#endif
Amerigo Wang0cf062d2009-09-23 15:57:05 -07001683 return 1;
1684#ifdef ELF_CORE_COPY_XFPREGS
1685 fpu_free:
1686 kfree(info->fpu);
1687#endif
1688 prstatus_free:
1689 kfree(info->prstatus);
1690 psinfo_free:
1691 kfree(info->psinfo);
1692 notes_free:
1693 kfree(info->notes);
1694 return 0;
1695}
Roland McGrath3aba4812008-01-30 13:31:44 +01001696
Amerigo Wang0cf062d2009-09-23 15:57:05 -07001697static int fill_note_info(struct elfhdr *elf, int phdrs,
1698 struct elf_note_info *info,
1699 long signr, struct pt_regs *regs)
1700{
1701 struct list_head *t;
1702
1703 if (!elf_note_info_init(info))
1704 return 0;
1705
Roland McGrath3aba4812008-01-30 13:31:44 +01001706 if (signr) {
Oleg Nesterov83914442008-07-25 01:47:45 -07001707 struct core_thread *ct;
WANG Cong4220b7f2008-04-29 01:01:18 -07001708 struct elf_thread_status *ets;
Oleg Nesterov24d52882008-07-25 01:47:40 -07001709
Oleg Nesterov83914442008-07-25 01:47:45 -07001710 for (ct = current->mm->core_state->dumper.next;
1711 ct; ct = ct->next) {
1712 ets = kzalloc(sizeof(*ets), GFP_KERNEL);
1713 if (!ets)
1714 return 0;
1715
1716 ets->thread = ct->task;
1717 list_add(&ets->list, &info->thread_list);
1718 }
1719
Roland McGrath3aba4812008-01-30 13:31:44 +01001720 list_for_each(t, &info->thread_list) {
Roland McGrath3aba4812008-01-30 13:31:44 +01001721 int sz;
1722
WANG Cong4220b7f2008-04-29 01:01:18 -07001723 ets = list_entry(t, struct elf_thread_status, list);
1724 sz = elf_dump_thread_status(signr, ets);
Roland McGrath3aba4812008-01-30 13:31:44 +01001725 info->thread_status_size += sz;
1726 }
1727 }
1728 /* now collect the dump for the current */
1729 memset(info->prstatus, 0, sizeof(*info->prstatus));
1730 fill_prstatus(info->prstatus, current, signr);
1731 elf_core_copy_regs(&info->prstatus->pr_reg, regs);
1732
1733 /* Set up header */
1734 fill_elf_header(elf, phdrs, ELF_ARCH, ELF_CORE_EFLAGS, ELF_OSABI);
1735
1736 /*
1737 * Set up the notes in similar form to SVR4 core dumps made
1738 * with info from their /proc.
1739 */
1740
1741 fill_note(info->notes + 0, "CORE", NT_PRSTATUS,
1742 sizeof(*info->prstatus), info->prstatus);
1743 fill_psinfo(info->psinfo, current->group_leader, current->mm);
1744 fill_note(info->notes + 1, "CORE", NT_PRPSINFO,
1745 sizeof(*info->psinfo), info->psinfo);
1746
1747 info->numnote = 2;
1748
1749 fill_auxv_note(&info->notes[info->numnote++], current->mm);
1750
1751 /* Try to dump the FPU. */
1752 info->prstatus->pr_fpvalid = elf_core_copy_task_fpregs(current, regs,
1753 info->fpu);
1754 if (info->prstatus->pr_fpvalid)
1755 fill_note(info->notes + info->numnote++,
1756 "CORE", NT_PRFPREG, sizeof(*info->fpu), info->fpu);
1757#ifdef ELF_CORE_COPY_XFPREGS
1758 if (elf_core_copy_task_xfpregs(current, info->xfpu))
1759 fill_note(info->notes + info->numnote++,
1760 "LINUX", ELF_CORE_XFPREG_TYPE,
1761 sizeof(*info->xfpu), info->xfpu);
1762#endif
1763
1764 return 1;
Roland McGrath3aba4812008-01-30 13:31:44 +01001765}
1766
1767static size_t get_note_info_size(struct elf_note_info *info)
1768{
1769 int sz = 0;
1770 int i;
1771
1772 for (i = 0; i < info->numnote; i++)
1773 sz += notesize(info->notes + i);
1774
1775 sz += info->thread_status_size;
1776
1777 return sz;
1778}
1779
1780static int write_note_info(struct elf_note_info *info,
1781 struct file *file, loff_t *foffset)
1782{
1783 int i;
1784 struct list_head *t;
1785
1786 for (i = 0; i < info->numnote; i++)
1787 if (!writenote(info->notes + i, file, foffset))
1788 return 0;
1789
1790 /* write out the thread status notes section */
1791 list_for_each(t, &info->thread_list) {
1792 struct elf_thread_status *tmp =
1793 list_entry(t, struct elf_thread_status, list);
1794
1795 for (i = 0; i < tmp->num_notes; i++)
1796 if (!writenote(&tmp->notes[i], file, foffset))
1797 return 0;
1798 }
1799
1800 return 1;
1801}
1802
1803static void free_note_info(struct elf_note_info *info)
1804{
1805 while (!list_empty(&info->thread_list)) {
1806 struct list_head *tmp = info->thread_list.next;
1807 list_del(tmp);
1808 kfree(list_entry(tmp, struct elf_thread_status, list));
1809 }
1810
1811 kfree(info->prstatus);
1812 kfree(info->psinfo);
1813 kfree(info->notes);
1814 kfree(info->fpu);
1815#ifdef ELF_CORE_COPY_XFPREGS
1816 kfree(info->xfpu);
1817#endif
1818}
1819
Roland McGrath4206d3a2008-01-30 13:31:45 +01001820#endif
1821
Roland McGrathf47aef52007-01-26 00:56:49 -08001822static struct vm_area_struct *first_vma(struct task_struct *tsk,
1823 struct vm_area_struct *gate_vma)
1824{
1825 struct vm_area_struct *ret = tsk->mm->mmap;
1826
1827 if (ret)
1828 return ret;
1829 return gate_vma;
1830}
1831/*
1832 * Helper function for iterating across a vma list. It ensures that the caller
1833 * will visit `gate_vma' prior to terminating the search.
1834 */
1835static struct vm_area_struct *next_vma(struct vm_area_struct *this_vma,
1836 struct vm_area_struct *gate_vma)
1837{
1838 struct vm_area_struct *ret;
1839
1840 ret = this_vma->vm_next;
1841 if (ret)
1842 return ret;
1843 if (this_vma == gate_vma)
1844 return NULL;
1845 return gate_vma;
1846}
1847
Daisuke HATAYAMA8d9032b2010-03-05 13:44:10 -08001848static void fill_extnum_info(struct elfhdr *elf, struct elf_shdr *shdr4extnum,
1849 elf_addr_t e_shoff, int segs)
1850{
1851 elf->e_shoff = e_shoff;
1852 elf->e_shentsize = sizeof(*shdr4extnum);
1853 elf->e_shnum = 1;
1854 elf->e_shstrndx = SHN_UNDEF;
1855
1856 memset(shdr4extnum, 0, sizeof(*shdr4extnum));
1857
1858 shdr4extnum->sh_type = SHT_NULL;
1859 shdr4extnum->sh_size = elf->e_shnum;
1860 shdr4extnum->sh_link = elf->e_shstrndx;
1861 shdr4extnum->sh_info = segs;
1862}
1863
1864static size_t elf_core_vma_data_size(struct vm_area_struct *gate_vma,
1865 unsigned long mm_flags)
1866{
1867 struct vm_area_struct *vma;
1868 size_t size = 0;
1869
1870 for (vma = first_vma(current, gate_vma); vma != NULL;
1871 vma = next_vma(vma, gate_vma))
1872 size += vma_dump_size(vma, mm_flags);
1873 return size;
1874}
1875
Linus Torvalds1da177e2005-04-16 15:20:36 -07001876/*
1877 * Actual dumper
1878 *
1879 * This is a two-pass process; first we find the offsets of the bits,
1880 * and then they are actually written out. If we run out of core limit
1881 * we just truncate.
1882 */
Masami Hiramatsuf6151df2009-12-17 15:27:16 -08001883static int elf_core_dump(struct coredump_params *cprm)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001884{
Linus Torvalds1da177e2005-04-16 15:20:36 -07001885 int has_dumped = 0;
1886 mm_segment_t fs;
1887 int segs;
1888 size_t size = 0;
Roland McGrathf47aef52007-01-26 00:56:49 -08001889 struct vm_area_struct *vma, *gate_vma;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001890 struct elfhdr *elf = NULL;
Andi Kleend025c9d2006-09-30 23:29:28 -07001891 loff_t offset = 0, dataoff, foffset;
Roland McGrath3aba4812008-01-30 13:31:44 +01001892 struct elf_note_info info;
Daisuke HATAYAMA93eb2112010-03-05 13:44:09 -08001893 struct elf_phdr *phdr4note = NULL;
Daisuke HATAYAMA8d9032b2010-03-05 13:44:10 -08001894 struct elf_shdr *shdr4extnum = NULL;
1895 Elf_Half e_phnum;
1896 elf_addr_t e_shoff;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001897
1898 /*
1899 * We no longer stop all VM operations.
1900 *
Jesper Juhlf4e5cc22006-06-23 02:05:35 -07001901 * This is because those proceses that could possibly change map_count
1902 * or the mmap / vma pages are now blocked in do_exit on current
1903 * finishing this core dump.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001904 *
1905 * Only ptrace can touch these memory addresses, but it doesn't change
Jesper Juhlf4e5cc22006-06-23 02:05:35 -07001906 * the map_count or the pages allocated. So no possibility of crashing
Linus Torvalds1da177e2005-04-16 15:20:36 -07001907 * exists while dumping the mm->vm_next areas to the core file.
1908 */
1909
1910 /* alloc memory for large data structures: too large to be on stack */
1911 elf = kmalloc(sizeof(*elf), GFP_KERNEL);
1912 if (!elf)
WANG Cong5f719552008-05-06 12:45:35 +08001913 goto out;
KAMEZAWA Hiroyuki341c87b2009-06-30 11:41:23 -07001914 /*
1915 * The number of segs are recored into ELF header as 16bit value.
1916 * Please check DEFAULT_MAX_MAP_COUNT definition when you modify here.
1917 */
Linus Torvalds1da177e2005-04-16 15:20:36 -07001918 segs = current->mm->map_count;
Daisuke HATAYAMA1fcccba2010-03-05 13:44:07 -08001919 segs += elf_core_extra_phdrs();
Linus Torvalds1da177e2005-04-16 15:20:36 -07001920
Stephen Wilson31db58b2011-03-13 15:49:15 -04001921 gate_vma = get_gate_vma(current->mm);
Roland McGrathf47aef52007-01-26 00:56:49 -08001922 if (gate_vma != NULL)
1923 segs++;
1924
Daisuke HATAYAMA8d9032b2010-03-05 13:44:10 -08001925 /* for notes section */
1926 segs++;
1927
1928 /* If segs > PN_XNUM(0xffff), then e_phnum overflows. To avoid
1929 * this, kernel supports extended numbering. Have a look at
1930 * include/linux/elf.h for further information. */
1931 e_phnum = segs > PN_XNUM ? PN_XNUM : segs;
1932
Roland McGrath3aba4812008-01-30 13:31:44 +01001933 /*
1934 * Collect all the non-memory information about the process for the
1935 * notes. This also sets up the file header.
1936 */
Daisuke HATAYAMA8d9032b2010-03-05 13:44:10 -08001937 if (!fill_note_info(elf, e_phnum, &info, cprm->signr, cprm->regs))
Roland McGrath3aba4812008-01-30 13:31:44 +01001938 goto cleanup;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001939
1940 has_dumped = 1;
1941 current->flags |= PF_DUMPCORE;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001942
1943 fs = get_fs();
1944 set_fs(KERNEL_DS);
1945
Linus Torvalds1da177e2005-04-16 15:20:36 -07001946 offset += sizeof(*elf); /* Elf header */
Daisuke HATAYAMA8d9032b2010-03-05 13:44:10 -08001947 offset += segs * sizeof(struct elf_phdr); /* Program headers */
Petr Vandroveca7a0d862006-10-13 18:42:07 +02001948 foffset = offset;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001949
1950 /* Write notes phdr entry */
1951 {
Roland McGrath3aba4812008-01-30 13:31:44 +01001952 size_t sz = get_note_info_size(&info);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001953
Michael Ellermane5501492007-09-19 14:38:12 +10001954 sz += elf_coredump_extra_notes_size();
Dwayne Grant McConnellbf1ab972006-11-23 00:46:37 +01001955
Daisuke HATAYAMA93eb2112010-03-05 13:44:09 -08001956 phdr4note = kmalloc(sizeof(*phdr4note), GFP_KERNEL);
1957 if (!phdr4note)
Daisuke HATAYAMA088e7af2010-03-05 13:44:06 -08001958 goto end_coredump;
Daisuke HATAYAMA93eb2112010-03-05 13:44:09 -08001959
1960 fill_elf_note_phdr(phdr4note, sz, offset);
1961 offset += sz;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001962 }
1963
Linus Torvalds1da177e2005-04-16 15:20:36 -07001964 dataoff = offset = roundup(offset, ELF_EXEC_PAGESIZE);
1965
Masami Hiramatsu30736a42010-03-05 13:44:12 -08001966 offset += elf_core_vma_data_size(gate_vma, cprm->mm_flags);
Daisuke HATAYAMA8d9032b2010-03-05 13:44:10 -08001967 offset += elf_core_extra_data_size();
1968 e_shoff = offset;
1969
1970 if (e_phnum == PN_XNUM) {
1971 shdr4extnum = kmalloc(sizeof(*shdr4extnum), GFP_KERNEL);
1972 if (!shdr4extnum)
1973 goto end_coredump;
1974 fill_extnum_info(elf, shdr4extnum, e_shoff, segs);
1975 }
1976
1977 offset = dataoff;
1978
Daisuke HATAYAMA93eb2112010-03-05 13:44:09 -08001979 size += sizeof(*elf);
1980 if (size > cprm->limit || !dump_write(cprm->file, elf, sizeof(*elf)))
1981 goto end_coredump;
1982
1983 size += sizeof(*phdr4note);
1984 if (size > cprm->limit
1985 || !dump_write(cprm->file, phdr4note, sizeof(*phdr4note)))
1986 goto end_coredump;
1987
Linus Torvalds1da177e2005-04-16 15:20:36 -07001988 /* Write program headers for segments dump */
Roland McGrathf47aef52007-01-26 00:56:49 -08001989 for (vma = first_vma(current, gate_vma); vma != NULL;
1990 vma = next_vma(vma, gate_vma)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001991 struct elf_phdr phdr;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001992
1993 phdr.p_type = PT_LOAD;
1994 phdr.p_offset = offset;
1995 phdr.p_vaddr = vma->vm_start;
1996 phdr.p_paddr = 0;
Masami Hiramatsu30736a42010-03-05 13:44:12 -08001997 phdr.p_filesz = vma_dump_size(vma, cprm->mm_flags);
Roland McGrath82df3972007-10-16 23:27:02 -07001998 phdr.p_memsz = vma->vm_end - vma->vm_start;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001999 offset += phdr.p_filesz;
2000 phdr.p_flags = vma->vm_flags & VM_READ ? PF_R : 0;
Jesper Juhlf4e5cc22006-06-23 02:05:35 -07002001 if (vma->vm_flags & VM_WRITE)
2002 phdr.p_flags |= PF_W;
2003 if (vma->vm_flags & VM_EXEC)
2004 phdr.p_flags |= PF_X;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002005 phdr.p_align = ELF_EXEC_PAGESIZE;
2006
Daisuke HATAYAMA088e7af2010-03-05 13:44:06 -08002007 size += sizeof(phdr);
2008 if (size > cprm->limit
2009 || !dump_write(cprm->file, &phdr, sizeof(phdr)))
2010 goto end_coredump;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002011 }
2012
Daisuke HATAYAMA1fcccba2010-03-05 13:44:07 -08002013 if (!elf_core_write_extra_phdrs(cprm->file, offset, &size, cprm->limit))
2014 goto end_coredump;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002015
2016 /* write out the notes section */
Masami Hiramatsuf6151df2009-12-17 15:27:16 -08002017 if (!write_note_info(&info, cprm->file, &foffset))
Roland McGrath3aba4812008-01-30 13:31:44 +01002018 goto end_coredump;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002019
Masami Hiramatsuf6151df2009-12-17 15:27:16 -08002020 if (elf_coredump_extra_notes_write(cprm->file, &foffset))
Michael Ellermane5501492007-09-19 14:38:12 +10002021 goto end_coredump;
Dwayne Grant McConnellbf1ab972006-11-23 00:46:37 +01002022
Andi Kleend025c9d2006-09-30 23:29:28 -07002023 /* Align to page */
Masami Hiramatsuf6151df2009-12-17 15:27:16 -08002024 if (!dump_seek(cprm->file, dataoff - foffset))
Hugh Dickinsf3e8fcc2009-09-21 17:03:25 -07002025 goto end_coredump;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002026
Roland McGrathf47aef52007-01-26 00:56:49 -08002027 for (vma = first_vma(current, gate_vma); vma != NULL;
2028 vma = next_vma(vma, gate_vma)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07002029 unsigned long addr;
Roland McGrath82df3972007-10-16 23:27:02 -07002030 unsigned long end;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002031
Masami Hiramatsu30736a42010-03-05 13:44:12 -08002032 end = vma->vm_start + vma_dump_size(vma, cprm->mm_flags);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002033
Roland McGrath82df3972007-10-16 23:27:02 -07002034 for (addr = vma->vm_start; addr < end; addr += PAGE_SIZE) {
Jesper Juhlf4e5cc22006-06-23 02:05:35 -07002035 struct page *page;
Hugh Dickinsf3e8fcc2009-09-21 17:03:25 -07002036 int stop;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002037
Hugh Dickinsf3e8fcc2009-09-21 17:03:25 -07002038 page = get_dump_page(addr);
2039 if (page) {
2040 void *kaddr = kmap(page);
Masami Hiramatsuf6151df2009-12-17 15:27:16 -08002041 stop = ((size += PAGE_SIZE) > cprm->limit) ||
2042 !dump_write(cprm->file, kaddr,
2043 PAGE_SIZE);
Hugh Dickinsf3e8fcc2009-09-21 17:03:25 -07002044 kunmap(page);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002045 page_cache_release(page);
Hugh Dickinsf3e8fcc2009-09-21 17:03:25 -07002046 } else
Masami Hiramatsuf6151df2009-12-17 15:27:16 -08002047 stop = !dump_seek(cprm->file, PAGE_SIZE);
Hugh Dickinsf3e8fcc2009-09-21 17:03:25 -07002048 if (stop)
2049 goto end_coredump;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002050 }
2051 }
2052
Daisuke HATAYAMA1fcccba2010-03-05 13:44:07 -08002053 if (!elf_core_write_extra_data(cprm->file, &size, cprm->limit))
2054 goto end_coredump;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002055
Daisuke HATAYAMA8d9032b2010-03-05 13:44:10 -08002056 if (e_phnum == PN_XNUM) {
2057 size += sizeof(*shdr4extnum);
2058 if (size > cprm->limit
2059 || !dump_write(cprm->file, shdr4extnum,
2060 sizeof(*shdr4extnum)))
2061 goto end_coredump;
2062 }
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);
Daisuke HATAYAMA8d9032b2010-03-05 13:44:10 -08002069 kfree(shdr4extnum);
Daisuke HATAYAMA93eb2112010-03-05 13:44:09 -08002070 kfree(phdr4note);
WANG Cong5f719552008-05-06 12:45:35 +08002071 kfree(elf);
2072out:
Linus Torvalds1da177e2005-04-16 15:20:36 -07002073 return has_dumped;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002074}
2075
Christoph Hellwig698ba7b2009-12-15 16:47:37 -08002076#endif /* CONFIG_ELF_CORE */
Linus Torvalds1da177e2005-04-16 15:20:36 -07002077
2078static int __init init_elf_binfmt(void)
2079{
2080 return register_binfmt(&elf_format);
2081}
2082
2083static void __exit exit_elf_binfmt(void)
2084{
2085 /* Remove the COFF and ELF loaders. */
2086 unregister_binfmt(&elf_format);
2087}
2088
2089core_initcall(init_elf_binfmt);
2090module_exit(exit_elf_binfmt);
2091MODULE_LICENSE("GPL");