blob: 08e4414b8374619bbf0d709893aece81877063a8 [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>
15#include <linux/stat.h>
16#include <linux/time.h>
17#include <linux/mm.h>
18#include <linux/mman.h>
19#include <linux/a.out.h>
20#include <linux/errno.h>
21#include <linux/signal.h>
22#include <linux/binfmts.h>
23#include <linux/string.h>
24#include <linux/file.h>
25#include <linux/fcntl.h>
26#include <linux/ptrace.h>
27#include <linux/slab.h>
28#include <linux/shm.h>
29#include <linux/personality.h>
30#include <linux/elfcore.h>
31#include <linux/init.h>
32#include <linux/highuid.h>
33#include <linux/smp.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070034#include <linux/compiler.h>
35#include <linux/highmem.h>
36#include <linux/pagemap.h>
37#include <linux/security.h>
38#include <linux/syscalls.h>
39#include <linux/random.h>
Jesper Juhlf4e5cc22006-06-23 02:05:35 -070040#include <linux/elf.h>
Alexey Dobriyan7e80d0d2007-05-08 00:28:59 -070041#include <linux/utsname.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070042#include <asm/uaccess.h>
43#include <asm/param.h>
44#include <asm/page.h>
45
Jesper Juhlf4e5cc22006-06-23 02:05:35 -070046static int load_elf_binary(struct linux_binprm *bprm, struct pt_regs *regs);
47static int load_elf_library(struct file *);
Linus Torvalds1da177e2005-04-16 15:20:36 -070048static unsigned long elf_map (struct file *, unsigned long, struct elf_phdr *, int, int);
Linus Torvalds1da177e2005-04-16 15:20:36 -070049
Linus Torvalds1da177e2005-04-16 15:20:36 -070050/*
51 * If we don't support core dumping, then supply a NULL so we
52 * don't even try.
53 */
Matt Mackall708e9a72006-01-08 01:05:25 -080054#if defined(USE_ELF_CORE_DUMP) && defined(CONFIG_ELF_CORE)
Jesper Juhlf4e5cc22006-06-23 02:05:35 -070055static int elf_core_dump(long signr, struct pt_regs *regs, struct file *file);
Linus Torvalds1da177e2005-04-16 15:20:36 -070056#else
57#define elf_core_dump NULL
58#endif
59
60#if ELF_EXEC_PAGESIZE > PAGE_SIZE
Jesper Juhlf4e5cc22006-06-23 02:05:35 -070061#define ELF_MIN_ALIGN ELF_EXEC_PAGESIZE
Linus Torvalds1da177e2005-04-16 15:20:36 -070062#else
Jesper Juhlf4e5cc22006-06-23 02:05:35 -070063#define ELF_MIN_ALIGN PAGE_SIZE
Linus Torvalds1da177e2005-04-16 15:20:36 -070064#endif
65
66#ifndef ELF_CORE_EFLAGS
67#define ELF_CORE_EFLAGS 0
68#endif
69
70#define ELF_PAGESTART(_v) ((_v) & ~(unsigned long)(ELF_MIN_ALIGN-1))
71#define ELF_PAGEOFFSET(_v) ((_v) & (ELF_MIN_ALIGN-1))
72#define ELF_PAGEALIGN(_v) (((_v) + ELF_MIN_ALIGN - 1) & ~(ELF_MIN_ALIGN - 1))
73
74static struct linux_binfmt elf_format = {
75 .module = THIS_MODULE,
76 .load_binary = load_elf_binary,
77 .load_shlib = load_elf_library,
78 .core_dump = elf_core_dump,
Andi Kleen9fbbd4d2007-02-13 13:26:26 +010079 .min_coredump = ELF_EXEC_PAGESIZE,
80 .hasvdso = 1
Linus Torvalds1da177e2005-04-16 15:20:36 -070081};
82
Chuck Ebbertce510592006-07-03 00:24:14 -070083#define BAD_ADDR(x) ((unsigned long)(x) >= TASK_SIZE)
Linus Torvalds1da177e2005-04-16 15:20:36 -070084
85static int set_brk(unsigned long start, unsigned long end)
86{
87 start = ELF_PAGEALIGN(start);
88 end = ELF_PAGEALIGN(end);
89 if (end > start) {
90 unsigned long addr;
91 down_write(&current->mm->mmap_sem);
92 addr = do_brk(start, end - start);
93 up_write(&current->mm->mmap_sem);
94 if (BAD_ADDR(addr))
95 return addr;
96 }
97 current->mm->start_brk = current->mm->brk = end;
98 return 0;
99}
100
Linus Torvalds1da177e2005-04-16 15:20:36 -0700101/* We need to explicitly zero any fractional pages
102 after the data section (i.e. bss). This would
103 contain the junk from the file that should not
Jesper Juhlf4e5cc22006-06-23 02:05:35 -0700104 be in memory
105 */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700106static int padzero(unsigned long elf_bss)
107{
108 unsigned long nbyte;
109
110 nbyte = ELF_PAGEOFFSET(elf_bss);
111 if (nbyte) {
112 nbyte = ELF_MIN_ALIGN - nbyte;
113 if (clear_user((void __user *) elf_bss, nbyte))
114 return -EFAULT;
115 }
116 return 0;
117}
118
119/* Let's use some macros to make this stack manipulation a litle clearer */
120#ifdef CONFIG_STACK_GROWSUP
121#define STACK_ADD(sp, items) ((elf_addr_t __user *)(sp) + (items))
122#define STACK_ROUND(sp, items) \
123 ((15 + (unsigned long) ((sp) + (items))) &~ 15UL)
Jesper Juhlf4e5cc22006-06-23 02:05:35 -0700124#define STACK_ALLOC(sp, len) ({ \
125 elf_addr_t __user *old_sp = (elf_addr_t __user *)sp; sp += len; \
126 old_sp; })
Linus Torvalds1da177e2005-04-16 15:20:36 -0700127#else
128#define STACK_ADD(sp, items) ((elf_addr_t __user *)(sp) - (items))
129#define STACK_ROUND(sp, items) \
130 (((unsigned long) (sp - items)) &~ 15UL)
131#define STACK_ALLOC(sp, len) ({ sp -= len ; sp; })
132#endif
133
134static int
Jesper Juhlf4e5cc22006-06-23 02:05:35 -0700135create_elf_tables(struct linux_binprm *bprm, struct elfhdr *exec,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700136 int interp_aout, unsigned long load_addr,
137 unsigned long interp_load_addr)
138{
139 unsigned long p = bprm->p;
140 int argc = bprm->argc;
141 int envc = bprm->envc;
142 elf_addr_t __user *argv;
143 elf_addr_t __user *envp;
144 elf_addr_t __user *sp;
145 elf_addr_t __user *u_platform;
146 const char *k_platform = ELF_PLATFORM;
147 int items;
148 elf_addr_t *elf_info;
149 int ei_index = 0;
150 struct task_struct *tsk = current;
151
152 /*
153 * If this architecture has a platform capability string, copy it
154 * to userspace. In some cases (Sparc), this info is impossible
155 * for userspace to get any other way, in others (i386) it is
156 * merely difficult.
157 */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700158 u_platform = NULL;
159 if (k_platform) {
160 size_t len = strlen(k_platform) + 1;
161
162 /*
163 * In some cases (e.g. Hyper-Threading), we want to avoid L1
164 * evictions by the processes running on the same package. One
165 * thing we can do is to shuffle the initial stack for them.
166 */
Jesper Juhlf4e5cc22006-06-23 02:05:35 -0700167
Linus Torvalds1da177e2005-04-16 15:20:36 -0700168 p = arch_align_stack(p);
169
170 u_platform = (elf_addr_t __user *)STACK_ALLOC(p, len);
171 if (__copy_to_user(u_platform, k_platform, len))
172 return -EFAULT;
173 }
174
175 /* Create the ELF interpreter info */
Jesper Juhl785d5572006-06-23 02:05:35 -0700176 elf_info = (elf_addr_t *)current->mm->saved_auxv;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700177#define NEW_AUX_ENT(id, val) \
Jesper Juhlf4e5cc22006-06-23 02:05:35 -0700178 do { \
Jesper Juhl785d5572006-06-23 02:05:35 -0700179 elf_info[ei_index++] = id; \
180 elf_info[ei_index++] = val; \
Jesper Juhlf4e5cc22006-06-23 02:05:35 -0700181 } while (0)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700182
183#ifdef ARCH_DLINFO
184 /*
185 * ARCH_DLINFO must come first so PPC can do its special alignment of
186 * AUXV.
187 */
188 ARCH_DLINFO;
189#endif
190 NEW_AUX_ENT(AT_HWCAP, ELF_HWCAP);
191 NEW_AUX_ENT(AT_PAGESZ, ELF_EXEC_PAGESIZE);
192 NEW_AUX_ENT(AT_CLKTCK, CLOCKS_PER_SEC);
193 NEW_AUX_ENT(AT_PHDR, load_addr + exec->e_phoff);
Jesper Juhlf4e5cc22006-06-23 02:05:35 -0700194 NEW_AUX_ENT(AT_PHENT, sizeof(struct elf_phdr));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700195 NEW_AUX_ENT(AT_PHNUM, exec->e_phnum);
196 NEW_AUX_ENT(AT_BASE, interp_load_addr);
197 NEW_AUX_ENT(AT_FLAGS, 0);
198 NEW_AUX_ENT(AT_ENTRY, exec->e_entry);
Jesper Juhl785d5572006-06-23 02:05:35 -0700199 NEW_AUX_ENT(AT_UID, tsk->uid);
200 NEW_AUX_ENT(AT_EUID, tsk->euid);
201 NEW_AUX_ENT(AT_GID, tsk->gid);
202 NEW_AUX_ENT(AT_EGID, tsk->egid);
203 NEW_AUX_ENT(AT_SECURE, security_bprm_secureexec(bprm));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700204 if (k_platform) {
Jesper Juhlf4e5cc22006-06-23 02:05:35 -0700205 NEW_AUX_ENT(AT_PLATFORM,
Jesper Juhl785d5572006-06-23 02:05:35 -0700206 (elf_addr_t)(unsigned long)u_platform);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700207 }
208 if (bprm->interp_flags & BINPRM_FLAGS_EXECFD) {
Jesper Juhl785d5572006-06-23 02:05:35 -0700209 NEW_AUX_ENT(AT_EXECFD, bprm->interp_data);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700210 }
211#undef NEW_AUX_ENT
212 /* AT_NULL is zero; clear the rest too */
213 memset(&elf_info[ei_index], 0,
214 sizeof current->mm->saved_auxv - ei_index * sizeof elf_info[0]);
215
216 /* And advance past the AT_NULL entry. */
217 ei_index += 2;
218
219 sp = STACK_ADD(p, ei_index);
220
221 items = (argc + 1) + (envc + 1);
222 if (interp_aout) {
223 items += 3; /* a.out interpreters require argv & envp too */
224 } else {
225 items += 1; /* ELF interpreters only put argc on the stack */
226 }
227 bprm->p = STACK_ROUND(sp, items);
228
229 /* Point sp at the lowest address on the stack */
230#ifdef CONFIG_STACK_GROWSUP
231 sp = (elf_addr_t __user *)bprm->p - items - ei_index;
Jesper Juhlf4e5cc22006-06-23 02:05:35 -0700232 bprm->exec = (unsigned long)sp; /* XXX: PARISC HACK */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700233#else
234 sp = (elf_addr_t __user *)bprm->p;
235#endif
236
237 /* Now, let's put argc (and argv, envp if appropriate) on the stack */
238 if (__put_user(argc, sp++))
239 return -EFAULT;
240 if (interp_aout) {
241 argv = sp + 2;
242 envp = argv + argc + 1;
Heiko Carstens841d5fb2006-12-06 20:36:35 -0800243 if (__put_user((elf_addr_t)(unsigned long)argv, sp++) ||
244 __put_user((elf_addr_t)(unsigned long)envp, sp++))
245 return -EFAULT;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700246 } else {
247 argv = sp;
248 envp = argv + argc + 1;
249 }
250
251 /* Populate argv and envp */
Greg Kroah-Hartmana84a5052005-05-11 00:10:44 -0700252 p = current->mm->arg_end = current->mm->arg_start;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700253 while (argc-- > 0) {
254 size_t len;
Heiko Carstens841d5fb2006-12-06 20:36:35 -0800255 if (__put_user((elf_addr_t)p, argv++))
256 return -EFAULT;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700257 len = strnlen_user((void __user *)p, PAGE_SIZE*MAX_ARG_PAGES);
258 if (!len || len > PAGE_SIZE*MAX_ARG_PAGES)
259 return 0;
260 p += len;
261 }
262 if (__put_user(0, argv))
263 return -EFAULT;
264 current->mm->arg_end = current->mm->env_start = p;
265 while (envc-- > 0) {
266 size_t len;
Heiko Carstens841d5fb2006-12-06 20:36:35 -0800267 if (__put_user((elf_addr_t)p, envp++))
268 return -EFAULT;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700269 len = strnlen_user((void __user *)p, PAGE_SIZE*MAX_ARG_PAGES);
270 if (!len || len > PAGE_SIZE*MAX_ARG_PAGES)
271 return 0;
272 p += len;
273 }
274 if (__put_user(0, envp))
275 return -EFAULT;
276 current->mm->env_end = p;
277
278 /* Put the elf_info on the stack in the right place. */
279 sp = (elf_addr_t __user *)envp + 1;
280 if (copy_to_user(sp, elf_info, ei_index * sizeof(elf_addr_t)))
281 return -EFAULT;
282 return 0;
283}
284
285#ifndef elf_map
286
287static unsigned long elf_map(struct file *filep, unsigned long addr,
Jesper Juhlf4e5cc22006-06-23 02:05:35 -0700288 struct elf_phdr *eppnt, int prot, int type)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700289{
290 unsigned long map_addr;
David Gibsondda6ebd2006-01-08 01:03:35 -0800291 unsigned long pageoffset = ELF_PAGEOFFSET(eppnt->p_vaddr);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700292
293 down_write(&current->mm->mmap_sem);
David Gibsondda6ebd2006-01-08 01:03:35 -0800294 /* mmap() will return -EINVAL if given a zero size, but a
295 * segment with zero filesize is perfectly valid */
296 if (eppnt->p_filesz + pageoffset)
297 map_addr = do_mmap(filep, ELF_PAGESTART(addr),
298 eppnt->p_filesz + pageoffset, prot, type,
299 eppnt->p_offset - pageoffset);
300 else
301 map_addr = ELF_PAGESTART(addr);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700302 up_write(&current->mm->mmap_sem);
303 return(map_addr);
304}
305
306#endif /* !elf_map */
307
308/* This is much more generalized than the library routine read function,
309 so we keep this separate. Technically the library read function
310 is only provided so that we can read a.out libraries that have
311 an ELF header */
312
Jesper Juhlf4e5cc22006-06-23 02:05:35 -0700313static unsigned long load_elf_interp(struct elfhdr *interp_elf_ex,
314 struct file *interpreter, unsigned long *interp_load_addr)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700315{
316 struct elf_phdr *elf_phdata;
317 struct elf_phdr *eppnt;
318 unsigned long load_addr = 0;
319 int load_addr_set = 0;
320 unsigned long last_bss = 0, elf_bss = 0;
321 unsigned long error = ~0UL;
322 int retval, i, size;
323
324 /* First of all, some simple consistency checks */
325 if (interp_elf_ex->e_type != ET_EXEC &&
326 interp_elf_ex->e_type != ET_DYN)
327 goto out;
328 if (!elf_check_arch(interp_elf_ex))
329 goto out;
330 if (!interpreter->f_op || !interpreter->f_op->mmap)
331 goto out;
332
333 /*
334 * If the size of this structure has changed, then punt, since
335 * we will be doing the wrong thing.
336 */
337 if (interp_elf_ex->e_phentsize != sizeof(struct elf_phdr))
338 goto out;
339 if (interp_elf_ex->e_phnum < 1 ||
340 interp_elf_ex->e_phnum > 65536U / sizeof(struct elf_phdr))
341 goto out;
342
343 /* Now read in all of the header information */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700344 size = sizeof(struct elf_phdr) * interp_elf_ex->e_phnum;
345 if (size > ELF_MIN_ALIGN)
346 goto out;
Jesper Juhlf4e5cc22006-06-23 02:05:35 -0700347 elf_phdata = kmalloc(size, GFP_KERNEL);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700348 if (!elf_phdata)
349 goto out;
350
Jesper Juhlf4e5cc22006-06-23 02:05:35 -0700351 retval = kernel_read(interpreter, interp_elf_ex->e_phoff,
352 (char *)elf_phdata,size);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700353 error = -EIO;
354 if (retval != size) {
355 if (retval < 0)
356 error = retval;
357 goto out_close;
358 }
359
360 eppnt = elf_phdata;
Jesper Juhlf4e5cc22006-06-23 02:05:35 -0700361 for (i = 0; i < interp_elf_ex->e_phnum; i++, eppnt++) {
362 if (eppnt->p_type == PT_LOAD) {
363 int elf_type = MAP_PRIVATE | MAP_DENYWRITE;
364 int elf_prot = 0;
365 unsigned long vaddr = 0;
366 unsigned long k, map_addr;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700367
Jesper Juhlf4e5cc22006-06-23 02:05:35 -0700368 if (eppnt->p_flags & PF_R)
369 elf_prot = PROT_READ;
370 if (eppnt->p_flags & PF_W)
371 elf_prot |= PROT_WRITE;
372 if (eppnt->p_flags & PF_X)
373 elf_prot |= PROT_EXEC;
374 vaddr = eppnt->p_vaddr;
375 if (interp_elf_ex->e_type == ET_EXEC || load_addr_set)
376 elf_type |= MAP_FIXED;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700377
Jesper Juhlf4e5cc22006-06-23 02:05:35 -0700378 map_addr = elf_map(interpreter, load_addr + vaddr,
379 eppnt, elf_prot, elf_type);
380 error = map_addr;
381 if (BAD_ADDR(map_addr))
382 goto out_close;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700383
Jesper Juhlf4e5cc22006-06-23 02:05:35 -0700384 if (!load_addr_set &&
385 interp_elf_ex->e_type == ET_DYN) {
386 load_addr = map_addr - ELF_PAGESTART(vaddr);
387 load_addr_set = 1;
388 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700389
Jesper Juhlf4e5cc22006-06-23 02:05:35 -0700390 /*
391 * Check to see if the section's size will overflow the
392 * allowed task size. Note that p_filesz must always be
393 * <= p_memsize so it's only necessary to check p_memsz.
394 */
395 k = load_addr + eppnt->p_vaddr;
Chuck Ebbertce510592006-07-03 00:24:14 -0700396 if (BAD_ADDR(k) ||
Jesper Juhlf4e5cc22006-06-23 02:05:35 -0700397 eppnt->p_filesz > eppnt->p_memsz ||
398 eppnt->p_memsz > TASK_SIZE ||
399 TASK_SIZE - eppnt->p_memsz < k) {
400 error = -ENOMEM;
401 goto out_close;
402 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700403
Jesper Juhlf4e5cc22006-06-23 02:05:35 -0700404 /*
405 * Find the end of the file mapping for this phdr, and
406 * keep track of the largest address we see for this.
407 */
408 k = load_addr + eppnt->p_vaddr + eppnt->p_filesz;
409 if (k > elf_bss)
410 elf_bss = k;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700411
Jesper Juhlf4e5cc22006-06-23 02:05:35 -0700412 /*
413 * Do the same thing for the memory mapping - between
414 * elf_bss and last_bss is the bss section.
415 */
416 k = load_addr + eppnt->p_memsz + eppnt->p_vaddr;
417 if (k > last_bss)
418 last_bss = k;
419 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700420 }
421
422 /*
423 * Now fill out the bss section. First pad the last page up
424 * to the page boundary, and then perform a mmap to make sure
425 * that there are zero-mapped pages up to and including the
426 * last bss page.
427 */
428 if (padzero(elf_bss)) {
429 error = -EFAULT;
430 goto out_close;
431 }
432
Jesper Juhlf4e5cc22006-06-23 02:05:35 -0700433 /* What we have mapped so far */
434 elf_bss = ELF_PAGESTART(elf_bss + ELF_MIN_ALIGN - 1);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700435
436 /* Map the last of the bss segment */
437 if (last_bss > elf_bss) {
438 down_write(&current->mm->mmap_sem);
439 error = do_brk(elf_bss, last_bss - elf_bss);
440 up_write(&current->mm->mmap_sem);
441 if (BAD_ADDR(error))
442 goto out_close;
443 }
444
445 *interp_load_addr = load_addr;
Jesper Juhlf4e5cc22006-06-23 02:05:35 -0700446 error = ((unsigned long)interp_elf_ex->e_entry) + load_addr;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700447
448out_close:
449 kfree(elf_phdata);
450out:
451 return error;
452}
453
Jesper Juhlf4e5cc22006-06-23 02:05:35 -0700454static unsigned long load_aout_interp(struct exec *interp_ex,
455 struct file *interpreter)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700456{
457 unsigned long text_data, elf_entry = ~0UL;
458 char __user * addr;
459 loff_t offset;
460
461 current->mm->end_code = interp_ex->a_text;
462 text_data = interp_ex->a_text + interp_ex->a_data;
463 current->mm->end_data = text_data;
464 current->mm->brk = interp_ex->a_bss + text_data;
465
466 switch (N_MAGIC(*interp_ex)) {
467 case OMAGIC:
468 offset = 32;
469 addr = (char __user *)0;
470 break;
471 case ZMAGIC:
472 case QMAGIC:
473 offset = N_TXTOFF(*interp_ex);
Jesper Juhlf4e5cc22006-06-23 02:05:35 -0700474 addr = (char __user *)N_TXTADDR(*interp_ex);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700475 break;
476 default:
477 goto out;
478 }
479
480 down_write(&current->mm->mmap_sem);
481 do_brk(0, text_data);
482 up_write(&current->mm->mmap_sem);
483 if (!interpreter->f_op || !interpreter->f_op->read)
484 goto out;
485 if (interpreter->f_op->read(interpreter, addr, text_data, &offset) < 0)
486 goto out;
487 flush_icache_range((unsigned long)addr,
488 (unsigned long)addr + text_data);
489
Linus Torvalds1da177e2005-04-16 15:20:36 -0700490 down_write(&current->mm->mmap_sem);
491 do_brk(ELF_PAGESTART(text_data + ELF_MIN_ALIGN - 1),
492 interp_ex->a_bss);
493 up_write(&current->mm->mmap_sem);
494 elf_entry = interp_ex->a_entry;
495
496out:
497 return elf_entry;
498}
499
500/*
501 * These are the functions used to load ELF style executables and shared
502 * libraries. There is no binary dependent code anywhere else.
503 */
504
505#define INTERPRETER_NONE 0
506#define INTERPRETER_AOUT 1
507#define INTERPRETER_ELF 2
508
Andi Kleen913bd902006-03-25 16:29:09 +0100509#ifndef STACK_RND_MASK
James Bottomleyd1cabd62007-03-16 13:38:35 -0800510#define STACK_RND_MASK (0x7ff >> (PAGE_SHIFT - 12)) /* 8MB of VA */
Andi Kleen913bd902006-03-25 16:29:09 +0100511#endif
Linus Torvalds1da177e2005-04-16 15:20:36 -0700512
513static unsigned long randomize_stack_top(unsigned long stack_top)
514{
515 unsigned int random_variable = 0;
516
Andi Kleenc16b63e02006-09-26 10:52:28 +0200517 if ((current->flags & PF_RANDOMIZE) &&
518 !(current->personality & ADDR_NO_RANDOMIZE)) {
Andi Kleen913bd902006-03-25 16:29:09 +0100519 random_variable = get_random_int() & STACK_RND_MASK;
520 random_variable <<= PAGE_SHIFT;
521 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700522#ifdef CONFIG_STACK_GROWSUP
Andi Kleen913bd902006-03-25 16:29:09 +0100523 return PAGE_ALIGN(stack_top) + random_variable;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700524#else
Andi Kleen913bd902006-03-25 16:29:09 +0100525 return PAGE_ALIGN(stack_top) - random_variable;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700526#endif
527}
528
Jesper Juhlf4e5cc22006-06-23 02:05:35 -0700529static int load_elf_binary(struct linux_binprm *bprm, struct pt_regs *regs)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700530{
531 struct file *interpreter = NULL; /* to shut gcc up */
532 unsigned long load_addr = 0, load_bias = 0;
533 int load_addr_set = 0;
534 char * elf_interpreter = NULL;
535 unsigned int interpreter_type = INTERPRETER_NONE;
536 unsigned char ibcs2_interpreter = 0;
537 unsigned long error;
Jesper Juhlf4e5cc22006-06-23 02:05:35 -0700538 struct elf_phdr *elf_ppnt, *elf_phdata;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700539 unsigned long elf_bss, elf_brk;
540 int elf_exec_fileno;
541 int retval, i;
542 unsigned int size;
543 unsigned long elf_entry, interp_load_addr = 0;
544 unsigned long start_code, end_code, start_data, end_data;
545 unsigned long reloc_func_desc = 0;
546 char passed_fileno[6];
547 struct files_struct *files;
David Rientjes8de61e62006-12-06 20:40:16 -0800548 int executable_stack = EXSTACK_DEFAULT;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700549 unsigned long def_flags = 0;
550 struct {
551 struct elfhdr elf_ex;
552 struct elfhdr interp_elf_ex;
553 struct exec interp_ex;
554 } *loc;
555
556 loc = kmalloc(sizeof(*loc), GFP_KERNEL);
557 if (!loc) {
558 retval = -ENOMEM;
559 goto out_ret;
560 }
561
562 /* Get the exec-header */
Jesper Juhlf4e5cc22006-06-23 02:05:35 -0700563 loc->elf_ex = *((struct elfhdr *)bprm->buf);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700564
565 retval = -ENOEXEC;
566 /* First of all, some simple consistency checks */
567 if (memcmp(loc->elf_ex.e_ident, ELFMAG, SELFMAG) != 0)
568 goto out;
569
570 if (loc->elf_ex.e_type != ET_EXEC && loc->elf_ex.e_type != ET_DYN)
571 goto out;
572 if (!elf_check_arch(&loc->elf_ex))
573 goto out;
574 if (!bprm->file->f_op||!bprm->file->f_op->mmap)
575 goto out;
576
577 /* Now read in all of the header information */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700578 if (loc->elf_ex.e_phentsize != sizeof(struct elf_phdr))
579 goto out;
580 if (loc->elf_ex.e_phnum < 1 ||
581 loc->elf_ex.e_phnum > 65536U / sizeof(struct elf_phdr))
582 goto out;
583 size = loc->elf_ex.e_phnum * sizeof(struct elf_phdr);
584 retval = -ENOMEM;
Jesper Juhlf4e5cc22006-06-23 02:05:35 -0700585 elf_phdata = kmalloc(size, GFP_KERNEL);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700586 if (!elf_phdata)
587 goto out;
588
Jesper Juhlf4e5cc22006-06-23 02:05:35 -0700589 retval = kernel_read(bprm->file, loc->elf_ex.e_phoff,
590 (char *)elf_phdata, size);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700591 if (retval != size) {
592 if (retval >= 0)
593 retval = -EIO;
594 goto out_free_ph;
595 }
596
Jesper Juhlf4e5cc22006-06-23 02:05:35 -0700597 files = current->files; /* Refcounted so ok */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700598 retval = unshare_files();
599 if (retval < 0)
600 goto out_free_ph;
601 if (files == current->files) {
602 put_files_struct(files);
603 files = NULL;
604 }
605
606 /* exec will make our files private anyway, but for the a.out
607 loader stuff we need to do it earlier */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700608 retval = get_unused_fd();
609 if (retval < 0)
610 goto out_free_fh;
611 get_file(bprm->file);
612 fd_install(elf_exec_fileno = retval, bprm->file);
613
614 elf_ppnt = elf_phdata;
615 elf_bss = 0;
616 elf_brk = 0;
617
618 start_code = ~0UL;
619 end_code = 0;
620 start_data = 0;
621 end_data = 0;
622
623 for (i = 0; i < loc->elf_ex.e_phnum; i++) {
624 if (elf_ppnt->p_type == PT_INTERP) {
625 /* This is the program interpreter used for
626 * shared libraries - for now assume that this
627 * is an a.out format binary
628 */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700629 retval = -ENOEXEC;
630 if (elf_ppnt->p_filesz > PATH_MAX ||
631 elf_ppnt->p_filesz < 2)
632 goto out_free_file;
633
634 retval = -ENOMEM;
Jesper Juhl792db3a2006-01-09 20:54:45 -0800635 elf_interpreter = kmalloc(elf_ppnt->p_filesz,
Jesper Juhlf4e5cc22006-06-23 02:05:35 -0700636 GFP_KERNEL);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700637 if (!elf_interpreter)
638 goto out_free_file;
639
640 retval = kernel_read(bprm->file, elf_ppnt->p_offset,
Jesper Juhlf4e5cc22006-06-23 02:05:35 -0700641 elf_interpreter,
642 elf_ppnt->p_filesz);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700643 if (retval != elf_ppnt->p_filesz) {
644 if (retval >= 0)
645 retval = -EIO;
646 goto out_free_interp;
647 }
648 /* make sure path is NULL terminated */
649 retval = -ENOEXEC;
650 if (elf_interpreter[elf_ppnt->p_filesz - 1] != '\0')
651 goto out_free_interp;
652
653 /* If the program interpreter is one of these two,
654 * then assume an iBCS2 image. Otherwise assume
655 * a native linux image.
656 */
657 if (strcmp(elf_interpreter,"/usr/lib/libc.so.1") == 0 ||
658 strcmp(elf_interpreter,"/usr/lib/ld.so.1") == 0)
659 ibcs2_interpreter = 1;
660
661 /*
662 * The early SET_PERSONALITY here is so that the lookup
663 * for the interpreter happens in the namespace of the
664 * to-be-execed image. SET_PERSONALITY can select an
665 * alternate root.
666 *
667 * However, SET_PERSONALITY is NOT allowed to switch
668 * this task into the new images's memory mapping
669 * policy - that is, TASK_SIZE must still evaluate to
670 * that which is appropriate to the execing application.
671 * This is because exit_mmap() needs to have TASK_SIZE
672 * evaluate to the size of the old image.
673 *
674 * So if (say) a 64-bit application is execing a 32-bit
675 * application it is the architecture's responsibility
676 * to defer changing the value of TASK_SIZE until the
677 * switch really is going to happen - do this in
678 * flush_thread(). - akpm
679 */
680 SET_PERSONALITY(loc->elf_ex, ibcs2_interpreter);
681
682 interpreter = open_exec(elf_interpreter);
683 retval = PTR_ERR(interpreter);
684 if (IS_ERR(interpreter))
685 goto out_free_interp;
Alexey Dobriyan1fb84492007-01-26 00:57:16 -0800686
687 /*
688 * If the binary is not readable then enforce
689 * mm->dumpable = 0 regardless of the interpreter's
690 * permissions.
691 */
692 if (file_permission(interpreter, MAY_READ) < 0)
693 bprm->interp_flags |= BINPRM_FLAGS_ENFORCE_NONDUMP;
694
Jesper Juhlf4e5cc22006-06-23 02:05:35 -0700695 retval = kernel_read(interpreter, 0, bprm->buf,
696 BINPRM_BUF_SIZE);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700697 if (retval != BINPRM_BUF_SIZE) {
698 if (retval >= 0)
699 retval = -EIO;
700 goto out_free_dentry;
701 }
702
703 /* Get the exec headers */
Jesper Juhlf4e5cc22006-06-23 02:05:35 -0700704 loc->interp_ex = *((struct exec *)bprm->buf);
705 loc->interp_elf_ex = *((struct elfhdr *)bprm->buf);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700706 break;
707 }
708 elf_ppnt++;
709 }
710
711 elf_ppnt = elf_phdata;
712 for (i = 0; i < loc->elf_ex.e_phnum; i++, elf_ppnt++)
713 if (elf_ppnt->p_type == PT_GNU_STACK) {
714 if (elf_ppnt->p_flags & PF_X)
715 executable_stack = EXSTACK_ENABLE_X;
716 else
717 executable_stack = EXSTACK_DISABLE_X;
718 break;
719 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700720
721 /* Some simple consistency checks for the interpreter */
722 if (elf_interpreter) {
723 interpreter_type = INTERPRETER_ELF | INTERPRETER_AOUT;
724
725 /* Now figure out which format our binary is */
726 if ((N_MAGIC(loc->interp_ex) != OMAGIC) &&
727 (N_MAGIC(loc->interp_ex) != ZMAGIC) &&
728 (N_MAGIC(loc->interp_ex) != QMAGIC))
729 interpreter_type = INTERPRETER_ELF;
730
731 if (memcmp(loc->interp_elf_ex.e_ident, ELFMAG, SELFMAG) != 0)
732 interpreter_type &= ~INTERPRETER_ELF;
733
734 retval = -ELIBBAD;
735 if (!interpreter_type)
736 goto out_free_dentry;
737
738 /* Make sure only one type was selected */
739 if ((interpreter_type & INTERPRETER_ELF) &&
740 interpreter_type != INTERPRETER_ELF) {
741 // FIXME - ratelimit this before re-enabling
742 // printk(KERN_WARNING "ELF: Ambiguous type, using ELF\n");
743 interpreter_type = INTERPRETER_ELF;
744 }
745 /* Verify the interpreter has a valid arch */
746 if ((interpreter_type == INTERPRETER_ELF) &&
747 !elf_check_arch(&loc->interp_elf_ex))
748 goto out_free_dentry;
749 } else {
750 /* Executables without an interpreter also need a personality */
751 SET_PERSONALITY(loc->elf_ex, ibcs2_interpreter);
752 }
753
754 /* OK, we are done with that, now set up the arg stuff,
755 and then start this sucker up */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700756 if ((!bprm->sh_bang) && (interpreter_type == INTERPRETER_AOUT)) {
757 char *passed_p = passed_fileno;
758 sprintf(passed_fileno, "%d", elf_exec_fileno);
759
760 if (elf_interpreter) {
761 retval = copy_strings_kernel(1, &passed_p, bprm);
762 if (retval)
763 goto out_free_dentry;
764 bprm->argc++;
765 }
766 }
767
768 /* Flush all traces of the currently running executable */
769 retval = flush_old_exec(bprm);
770 if (retval)
771 goto out_free_dentry;
772
773 /* Discard our unneeded old files struct */
774 if (files) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700775 put_files_struct(files);
776 files = NULL;
777 }
778
779 /* OK, This is the point of no return */
780 current->mm->start_data = 0;
781 current->mm->end_data = 0;
782 current->mm->end_code = 0;
783 current->mm->mmap = NULL;
784 current->flags &= ~PF_FORKNOEXEC;
785 current->mm->def_flags = def_flags;
786
787 /* Do this immediately, since STACK_TOP as used in setup_arg_pages
788 may depend on the personality. */
789 SET_PERSONALITY(loc->elf_ex, ibcs2_interpreter);
790 if (elf_read_implies_exec(loc->elf_ex, executable_stack))
791 current->personality |= READ_IMPLIES_EXEC;
792
Jesper Juhlf4e5cc22006-06-23 02:05:35 -0700793 if (!(current->personality & ADDR_NO_RANDOMIZE) && randomize_va_space)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700794 current->flags |= PF_RANDOMIZE;
795 arch_pick_mmap_layout(current->mm);
796
797 /* Do this so that we can load the interpreter, if need be. We will
798 change some of these later */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700799 current->mm->free_area_cache = current->mm->mmap_base;
Wolfgang Wander1363c3c2005-06-21 17:14:49 -0700800 current->mm->cached_hole_size = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700801 retval = setup_arg_pages(bprm, randomize_stack_top(STACK_TOP),
802 executable_stack);
803 if (retval < 0) {
804 send_sig(SIGKILL, current, 0);
805 goto out_free_dentry;
806 }
807
Linus Torvalds1da177e2005-04-16 15:20:36 -0700808 current->mm->start_stack = bprm->p;
809
810 /* Now we do a little grungy work by mmaping the ELF image into
811 the correct location in memory. At this point, we assume that
812 the image should be loaded at fixed address, not at a variable
813 address. */
Jesper Juhlf4e5cc22006-06-23 02:05:35 -0700814 for(i = 0, elf_ppnt = elf_phdata;
815 i < loc->elf_ex.e_phnum; i++, elf_ppnt++) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700816 int elf_prot = 0, elf_flags;
817 unsigned long k, vaddr;
818
819 if (elf_ppnt->p_type != PT_LOAD)
820 continue;
821
822 if (unlikely (elf_brk > elf_bss)) {
823 unsigned long nbyte;
824
825 /* There was a PT_LOAD segment with p_memsz > p_filesz
826 before this one. Map anonymous pages, if needed,
827 and clear the area. */
828 retval = set_brk (elf_bss + load_bias,
829 elf_brk + load_bias);
830 if (retval) {
831 send_sig(SIGKILL, current, 0);
832 goto out_free_dentry;
833 }
834 nbyte = ELF_PAGEOFFSET(elf_bss);
835 if (nbyte) {
836 nbyte = ELF_MIN_ALIGN - nbyte;
837 if (nbyte > elf_brk - elf_bss)
838 nbyte = elf_brk - elf_bss;
839 if (clear_user((void __user *)elf_bss +
840 load_bias, nbyte)) {
841 /*
842 * This bss-zeroing can fail if the ELF
Jesper Juhlf4e5cc22006-06-23 02:05:35 -0700843 * file specifies odd protections. So
Linus Torvalds1da177e2005-04-16 15:20:36 -0700844 * we don't check the return value
845 */
846 }
847 }
848 }
849
Jesper Juhlf4e5cc22006-06-23 02:05:35 -0700850 if (elf_ppnt->p_flags & PF_R)
851 elf_prot |= PROT_READ;
852 if (elf_ppnt->p_flags & PF_W)
853 elf_prot |= PROT_WRITE;
854 if (elf_ppnt->p_flags & PF_X)
855 elf_prot |= PROT_EXEC;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700856
Jesper Juhlf4e5cc22006-06-23 02:05:35 -0700857 elf_flags = MAP_PRIVATE | MAP_DENYWRITE | MAP_EXECUTABLE;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700858
859 vaddr = elf_ppnt->p_vaddr;
860 if (loc->elf_ex.e_type == ET_EXEC || load_addr_set) {
861 elf_flags |= MAP_FIXED;
862 } else if (loc->elf_ex.e_type == ET_DYN) {
Jesper Juhlf4e5cc22006-06-23 02:05:35 -0700863 /* Try and get dynamic programs out of the way of the
864 * default mmap base, as well as whatever program they
865 * might try to exec. This is because the brk will
866 * follow the loader, and is not movable. */
Linus Torvalds90cb28e2007-01-06 13:28:21 -0800867 load_bias = ELF_PAGESTART(ELF_ET_DYN_BASE - vaddr);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700868 }
869
Jesper Juhlf4e5cc22006-06-23 02:05:35 -0700870 error = elf_map(bprm->file, load_bias + vaddr, elf_ppnt,
871 elf_prot, elf_flags);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700872 if (BAD_ADDR(error)) {
873 send_sig(SIGKILL, current, 0);
Alexey Kuznetsovb140f2512007-05-08 00:31:57 -0700874 retval = IS_ERR((void *)error) ?
875 PTR_ERR((void*)error) : -EINVAL;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700876 goto out_free_dentry;
877 }
878
879 if (!load_addr_set) {
880 load_addr_set = 1;
881 load_addr = (elf_ppnt->p_vaddr - elf_ppnt->p_offset);
882 if (loc->elf_ex.e_type == ET_DYN) {
883 load_bias += error -
884 ELF_PAGESTART(load_bias + vaddr);
885 load_addr += load_bias;
886 reloc_func_desc = load_bias;
887 }
888 }
889 k = elf_ppnt->p_vaddr;
Jesper Juhlf4e5cc22006-06-23 02:05:35 -0700890 if (k < start_code)
891 start_code = k;
892 if (start_data < k)
893 start_data = k;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700894
895 /*
896 * Check to see if the section's size will overflow the
897 * allowed task size. Note that p_filesz must always be
898 * <= p_memsz so it is only necessary to check p_memsz.
899 */
Chuck Ebbertce510592006-07-03 00:24:14 -0700900 if (BAD_ADDR(k) || elf_ppnt->p_filesz > elf_ppnt->p_memsz ||
Linus Torvalds1da177e2005-04-16 15:20:36 -0700901 elf_ppnt->p_memsz > TASK_SIZE ||
902 TASK_SIZE - elf_ppnt->p_memsz < k) {
Jesper Juhlf4e5cc22006-06-23 02:05:35 -0700903 /* set_brk can never work. Avoid overflows. */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700904 send_sig(SIGKILL, current, 0);
Alexey Kuznetsovb140f2512007-05-08 00:31:57 -0700905 retval = -EINVAL;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700906 goto out_free_dentry;
907 }
908
909 k = elf_ppnt->p_vaddr + elf_ppnt->p_filesz;
910
911 if (k > elf_bss)
912 elf_bss = k;
913 if ((elf_ppnt->p_flags & PF_X) && end_code < k)
914 end_code = k;
915 if (end_data < k)
916 end_data = k;
917 k = elf_ppnt->p_vaddr + elf_ppnt->p_memsz;
918 if (k > elf_brk)
919 elf_brk = k;
920 }
921
922 loc->elf_ex.e_entry += load_bias;
923 elf_bss += load_bias;
924 elf_brk += load_bias;
925 start_code += load_bias;
926 end_code += load_bias;
927 start_data += load_bias;
928 end_data += load_bias;
929
930 /* Calling set_brk effectively mmaps the pages that we need
931 * for the bss and break sections. We must do this before
932 * mapping in the interpreter, to make sure it doesn't wind
933 * up getting placed where the bss needs to go.
934 */
935 retval = set_brk(elf_bss, elf_brk);
936 if (retval) {
937 send_sig(SIGKILL, current, 0);
938 goto out_free_dentry;
939 }
akpm@osdl.org6de50512005-10-11 08:29:08 -0700940 if (likely(elf_bss != elf_brk) && unlikely(padzero(elf_bss))) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700941 send_sig(SIGSEGV, current, 0);
942 retval = -EFAULT; /* Nobody gets to see this, but.. */
943 goto out_free_dentry;
944 }
945
946 if (elf_interpreter) {
947 if (interpreter_type == INTERPRETER_AOUT)
948 elf_entry = load_aout_interp(&loc->interp_ex,
949 interpreter);
950 else
951 elf_entry = load_elf_interp(&loc->interp_elf_ex,
952 interpreter,
953 &interp_load_addr);
954 if (BAD_ADDR(elf_entry)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700955 force_sig(SIGSEGV, current);
Chuck Ebbertce510592006-07-03 00:24:14 -0700956 retval = IS_ERR((void *)elf_entry) ?
957 (int)elf_entry : -EINVAL;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700958 goto out_free_dentry;
959 }
960 reloc_func_desc = interp_load_addr;
961
962 allow_write_access(interpreter);
963 fput(interpreter);
964 kfree(elf_interpreter);
965 } else {
966 elf_entry = loc->elf_ex.e_entry;
Suresh Siddha5342fba2006-02-26 04:18:28 +0100967 if (BAD_ADDR(elf_entry)) {
Chuck Ebbertce510592006-07-03 00:24:14 -0700968 force_sig(SIGSEGV, current);
969 retval = -EINVAL;
Suresh Siddha5342fba2006-02-26 04:18:28 +0100970 goto out_free_dentry;
971 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700972 }
973
974 kfree(elf_phdata);
975
976 if (interpreter_type != INTERPRETER_AOUT)
977 sys_close(elf_exec_fileno);
978
979 set_binfmt(&elf_format);
980
Benjamin Herrenschmidt547ee842005-04-16 15:24:35 -0700981#ifdef ARCH_HAS_SETUP_ADDITIONAL_PAGES
982 retval = arch_setup_additional_pages(bprm, executable_stack);
983 if (retval < 0) {
984 send_sig(SIGKILL, current, 0);
Roland McGrath18c8baf2005-04-28 15:17:19 -0700985 goto out;
Benjamin Herrenschmidt547ee842005-04-16 15:24:35 -0700986 }
987#endif /* ARCH_HAS_SETUP_ADDITIONAL_PAGES */
988
Linus Torvalds1da177e2005-04-16 15:20:36 -0700989 compute_creds(bprm);
990 current->flags &= ~PF_FORKNOEXEC;
Jesper Juhlf4e5cc22006-06-23 02:05:35 -0700991 create_elf_tables(bprm, &loc->elf_ex,
992 (interpreter_type == INTERPRETER_AOUT),
993 load_addr, interp_load_addr);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700994 /* N.B. passed_fileno might not be initialized? */
995 if (interpreter_type == INTERPRETER_AOUT)
996 current->mm->arg_start += strlen(passed_fileno) + 1;
997 current->mm->end_code = end_code;
998 current->mm->start_code = start_code;
999 current->mm->start_data = start_data;
1000 current->mm->end_data = end_data;
1001 current->mm->start_stack = bprm->p;
1002
1003 if (current->personality & MMAP_PAGE_ZERO) {
1004 /* Why this, you ask??? Well SVr4 maps page 0 as read-only,
1005 and some applications "depend" upon this behavior.
1006 Since we do not have the power to recompile these, we
Jesper Juhlf4e5cc22006-06-23 02:05:35 -07001007 emulate the SVr4 behavior. Sigh. */
Linus Torvalds1da177e2005-04-16 15:20:36 -07001008 down_write(&current->mm->mmap_sem);
1009 error = do_mmap(NULL, 0, PAGE_SIZE, PROT_READ | PROT_EXEC,
1010 MAP_FIXED | MAP_PRIVATE, 0);
1011 up_write(&current->mm->mmap_sem);
1012 }
1013
1014#ifdef ELF_PLAT_INIT
1015 /*
1016 * The ABI may specify that certain registers be set up in special
1017 * ways (on i386 %edx is the address of a DT_FINI function, for
1018 * example. In addition, it may also specify (eg, PowerPC64 ELF)
1019 * that the e_entry field is the address of the function descriptor
1020 * for the startup routine, rather than the address of the startup
1021 * routine itself. This macro performs whatever initialization to
1022 * the regs structure is required as well as any relocations to the
1023 * function descriptor entries when executing dynamically links apps.
1024 */
1025 ELF_PLAT_INIT(regs, reloc_func_desc);
1026#endif
1027
1028 start_thread(regs, elf_entry, bprm->p);
1029 if (unlikely(current->ptrace & PT_PTRACED)) {
1030 if (current->ptrace & PT_TRACE_EXEC)
1031 ptrace_notify ((PTRACE_EVENT_EXEC << 8) | SIGTRAP);
1032 else
1033 send_sig(SIGTRAP, current, 0);
1034 }
1035 retval = 0;
1036out:
1037 kfree(loc);
1038out_ret:
1039 return retval;
1040
1041 /* error cleanup */
1042out_free_dentry:
1043 allow_write_access(interpreter);
1044 if (interpreter)
1045 fput(interpreter);
1046out_free_interp:
Jesper Juhlf99d49a2005-11-07 01:01:34 -08001047 kfree(elf_interpreter);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001048out_free_file:
1049 sys_close(elf_exec_fileno);
1050out_free_fh:
Kirill Korotaev3b9b8ab2006-09-29 02:00:05 -07001051 if (files)
1052 reset_files_struct(current, files);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001053out_free_ph:
1054 kfree(elf_phdata);
1055 goto out;
1056}
1057
1058/* This is really simpleminded and specialized - we are loading an
1059 a.out library that is given an ELF header. */
Linus Torvalds1da177e2005-04-16 15:20:36 -07001060static int load_elf_library(struct file *file)
1061{
1062 struct elf_phdr *elf_phdata;
1063 struct elf_phdr *eppnt;
1064 unsigned long elf_bss, bss, len;
1065 int retval, error, i, j;
1066 struct elfhdr elf_ex;
1067
1068 error = -ENOEXEC;
Jesper Juhlf4e5cc22006-06-23 02:05:35 -07001069 retval = kernel_read(file, 0, (char *)&elf_ex, sizeof(elf_ex));
Linus Torvalds1da177e2005-04-16 15:20:36 -07001070 if (retval != sizeof(elf_ex))
1071 goto out;
1072
1073 if (memcmp(elf_ex.e_ident, ELFMAG, SELFMAG) != 0)
1074 goto out;
1075
1076 /* First of all, some simple consistency checks */
1077 if (elf_ex.e_type != ET_EXEC || elf_ex.e_phnum > 2 ||
Jesper Juhlf4e5cc22006-06-23 02:05:35 -07001078 !elf_check_arch(&elf_ex) || !file->f_op || !file->f_op->mmap)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001079 goto out;
1080
1081 /* Now read in all of the header information */
1082
1083 j = sizeof(struct elf_phdr) * elf_ex.e_phnum;
1084 /* j < ELF_MIN_ALIGN because elf_ex.e_phnum <= 2 */
1085
1086 error = -ENOMEM;
1087 elf_phdata = kmalloc(j, GFP_KERNEL);
1088 if (!elf_phdata)
1089 goto out;
1090
1091 eppnt = elf_phdata;
1092 error = -ENOEXEC;
1093 retval = kernel_read(file, elf_ex.e_phoff, (char *)eppnt, j);
1094 if (retval != j)
1095 goto out_free_ph;
1096
1097 for (j = 0, i = 0; i<elf_ex.e_phnum; i++)
1098 if ((eppnt + i)->p_type == PT_LOAD)
1099 j++;
1100 if (j != 1)
1101 goto out_free_ph;
1102
1103 while (eppnt->p_type != PT_LOAD)
1104 eppnt++;
1105
1106 /* Now use mmap to map the library into memory. */
1107 down_write(&current->mm->mmap_sem);
1108 error = do_mmap(file,
1109 ELF_PAGESTART(eppnt->p_vaddr),
1110 (eppnt->p_filesz +
1111 ELF_PAGEOFFSET(eppnt->p_vaddr)),
1112 PROT_READ | PROT_WRITE | PROT_EXEC,
1113 MAP_FIXED | MAP_PRIVATE | MAP_DENYWRITE,
1114 (eppnt->p_offset -
1115 ELF_PAGEOFFSET(eppnt->p_vaddr)));
1116 up_write(&current->mm->mmap_sem);
1117 if (error != ELF_PAGESTART(eppnt->p_vaddr))
1118 goto out_free_ph;
1119
1120 elf_bss = eppnt->p_vaddr + eppnt->p_filesz;
1121 if (padzero(elf_bss)) {
1122 error = -EFAULT;
1123 goto out_free_ph;
1124 }
1125
Jesper Juhlf4e5cc22006-06-23 02:05:35 -07001126 len = ELF_PAGESTART(eppnt->p_filesz + eppnt->p_vaddr +
1127 ELF_MIN_ALIGN - 1);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001128 bss = eppnt->p_memsz + eppnt->p_vaddr;
1129 if (bss > len) {
1130 down_write(&current->mm->mmap_sem);
1131 do_brk(len, bss - len);
1132 up_write(&current->mm->mmap_sem);
1133 }
1134 error = 0;
1135
1136out_free_ph:
1137 kfree(elf_phdata);
1138out:
1139 return error;
1140}
1141
1142/*
1143 * Note that some platforms still use traditional core dumps and not
1144 * the ELF core dump. Each platform can select it as appropriate.
1145 */
Matt Mackall708e9a72006-01-08 01:05:25 -08001146#if defined(USE_ELF_CORE_DUMP) && defined(CONFIG_ELF_CORE)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001147
1148/*
1149 * ELF core dumper
1150 *
1151 * Modelled on fs/exec.c:aout_core_dump()
1152 * Jeremy Fitzhardinge <jeremy@sw.oz.au>
1153 */
1154/*
1155 * These are the only things you should do on a core-file: use only these
1156 * functions to write out all the necessary info.
1157 */
1158static int dump_write(struct file *file, const void *addr, int nr)
1159{
1160 return file->f_op->write(file, addr, nr, &file->f_pos) == nr;
1161}
1162
Daniel Jacobowitz5db92852005-06-15 22:26:34 -07001163static int dump_seek(struct file *file, loff_t off)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001164{
Andi Kleend025c9d2006-09-30 23:29:28 -07001165 if (file->f_op->llseek && file->f_op->llseek != no_llseek) {
Petr Vandrovec7f14daa2006-10-13 04:13:16 +02001166 if (file->f_op->llseek(file, off, SEEK_CUR) < 0)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001167 return 0;
Andi Kleend025c9d2006-09-30 23:29:28 -07001168 } else {
1169 char *buf = (char *)get_zeroed_page(GFP_KERNEL);
1170 if (!buf)
1171 return 0;
1172 while (off > 0) {
1173 unsigned long n = off;
1174 if (n > PAGE_SIZE)
1175 n = PAGE_SIZE;
1176 if (!dump_write(file, buf, n))
1177 return 0;
1178 off -= n;
1179 }
1180 free_page((unsigned long)buf);
1181 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001182 return 1;
1183}
1184
1185/*
1186 * Decide whether a segment is worth dumping; default is yes to be
1187 * sure (missing info is worse than too much; etc).
1188 * Personally I'd include everything, and use the coredump limit...
1189 *
1190 * I think we should skip something. But I am not sure how. H.J.
1191 */
1192static int maydump(struct vm_area_struct *vma)
1193{
Roland McGrathe5b97dd2007-01-26 00:56:48 -08001194 /* The vma can be set up to tell us the answer directly. */
1195 if (vma->vm_flags & VM_ALWAYSDUMP)
1196 return 1;
1197
Linus Torvalds1da177e2005-04-16 15:20:36 -07001198 /* Do not dump I/O mapped devices or special mappings */
1199 if (vma->vm_flags & (VM_IO | VM_RESERVED))
1200 return 0;
1201
Jesper Juhlf4e5cc22006-06-23 02:05:35 -07001202 /* Dump shared memory only if mapped from an anonymous file. */
Linus Torvalds1da177e2005-04-16 15:20:36 -07001203 if (vma->vm_flags & VM_SHARED)
Josef "Jeff" Sipek0f7fc9e2006-12-08 02:36:35 -08001204 return vma->vm_file->f_path.dentry->d_inode->i_nlink == 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001205
1206 /* If it hasn't been written to, don't write it out */
1207 if (!vma->anon_vma)
1208 return 0;
1209
1210 return 1;
1211}
1212
Linus Torvalds1da177e2005-04-16 15:20:36 -07001213/* An ELF note in memory */
1214struct memelfnote
1215{
1216 const char *name;
1217 int type;
1218 unsigned int datasz;
1219 void *data;
1220};
1221
1222static int notesize(struct memelfnote *en)
1223{
1224 int sz;
1225
1226 sz = sizeof(struct elf_note);
1227 sz += roundup(strlen(en->name) + 1, 4);
1228 sz += roundup(en->datasz, 4);
1229
1230 return sz;
1231}
1232
Andi Kleend025c9d2006-09-30 23:29:28 -07001233#define DUMP_WRITE(addr, nr, foffset) \
1234 do { if (!dump_write(file, (addr), (nr))) return 0; *foffset += (nr); } while(0)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001235
Andi Kleend025c9d2006-09-30 23:29:28 -07001236static int alignfile(struct file *file, loff_t *foffset)
1237{
Petr Vandroveca7a0d862006-10-13 18:42:07 +02001238 static const char buf[4] = { 0, };
Andi Kleend025c9d2006-09-30 23:29:28 -07001239 DUMP_WRITE(buf, roundup(*foffset, 4) - *foffset, foffset);
1240 return 1;
1241}
1242
1243static int writenote(struct memelfnote *men, struct file *file,
1244 loff_t *foffset)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001245{
1246 struct elf_note en;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001247 en.n_namesz = strlen(men->name) + 1;
1248 en.n_descsz = men->datasz;
1249 en.n_type = men->type;
1250
Andi Kleend025c9d2006-09-30 23:29:28 -07001251 DUMP_WRITE(&en, sizeof(en), foffset);
1252 DUMP_WRITE(men->name, en.n_namesz, foffset);
1253 if (!alignfile(file, foffset))
1254 return 0;
1255 DUMP_WRITE(men->data, men->datasz, foffset);
1256 if (!alignfile(file, foffset))
1257 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001258
1259 return 1;
1260}
1261#undef DUMP_WRITE
Linus Torvalds1da177e2005-04-16 15:20:36 -07001262
1263#define DUMP_WRITE(addr, nr) \
1264 if ((size += (nr)) > limit || !dump_write(file, (addr), (nr))) \
1265 goto end_coredump;
1266#define DUMP_SEEK(off) \
1267 if (!dump_seek(file, (off))) \
1268 goto end_coredump;
1269
Arjan van de Ven858119e2006-01-14 13:20:43 -08001270static void fill_elf_header(struct elfhdr *elf, int segs)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001271{
1272 memcpy(elf->e_ident, ELFMAG, SELFMAG);
1273 elf->e_ident[EI_CLASS] = ELF_CLASS;
1274 elf->e_ident[EI_DATA] = ELF_DATA;
1275 elf->e_ident[EI_VERSION] = EV_CURRENT;
1276 elf->e_ident[EI_OSABI] = ELF_OSABI;
1277 memset(elf->e_ident+EI_PAD, 0, EI_NIDENT-EI_PAD);
1278
1279 elf->e_type = ET_CORE;
1280 elf->e_machine = ELF_ARCH;
1281 elf->e_version = EV_CURRENT;
1282 elf->e_entry = 0;
1283 elf->e_phoff = sizeof(struct elfhdr);
1284 elf->e_shoff = 0;
1285 elf->e_flags = ELF_CORE_EFLAGS;
1286 elf->e_ehsize = sizeof(struct elfhdr);
1287 elf->e_phentsize = sizeof(struct elf_phdr);
1288 elf->e_phnum = segs;
1289 elf->e_shentsize = 0;
1290 elf->e_shnum = 0;
1291 elf->e_shstrndx = 0;
1292 return;
1293}
1294
Andrew Morton8d6b5eee2006-09-25 23:32:04 -07001295static void fill_elf_note_phdr(struct elf_phdr *phdr, int sz, loff_t offset)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001296{
1297 phdr->p_type = PT_NOTE;
1298 phdr->p_offset = offset;
1299 phdr->p_vaddr = 0;
1300 phdr->p_paddr = 0;
1301 phdr->p_filesz = sz;
1302 phdr->p_memsz = 0;
1303 phdr->p_flags = 0;
1304 phdr->p_align = 0;
1305 return;
1306}
1307
1308static void fill_note(struct memelfnote *note, const char *name, int type,
1309 unsigned int sz, void *data)
1310{
1311 note->name = name;
1312 note->type = type;
1313 note->datasz = sz;
1314 note->data = data;
1315 return;
1316}
1317
1318/*
Jesper Juhlf4e5cc22006-06-23 02:05:35 -07001319 * fill up all the fields in prstatus from the given task struct, except
1320 * registers which need to be filled up separately.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001321 */
1322static void fill_prstatus(struct elf_prstatus *prstatus,
Jesper Juhlf4e5cc22006-06-23 02:05:35 -07001323 struct task_struct *p, long signr)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001324{
1325 prstatus->pr_info.si_signo = prstatus->pr_cursig = signr;
1326 prstatus->pr_sigpend = p->pending.signal.sig[0];
1327 prstatus->pr_sighold = p->blocked.sig[0];
1328 prstatus->pr_pid = p->pid;
1329 prstatus->pr_ppid = p->parent->pid;
1330 prstatus->pr_pgrp = process_group(p);
Cedric Le Goater937949d2006-12-08 02:37:54 -08001331 prstatus->pr_sid = process_session(p);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001332 if (thread_group_leader(p)) {
1333 /*
1334 * This is the record for the group leader. Add in the
1335 * cumulative times of previous dead threads. This total
1336 * won't include the time of each live thread whose state
1337 * is included in the core dump. The final total reported
1338 * to our parent process when it calls wait4 will include
1339 * those sums as well as the little bit more time it takes
1340 * this and each other thread to finish dying after the
1341 * core dump synchronization phase.
1342 */
1343 cputime_to_timeval(cputime_add(p->utime, p->signal->utime),
1344 &prstatus->pr_utime);
1345 cputime_to_timeval(cputime_add(p->stime, p->signal->stime),
1346 &prstatus->pr_stime);
1347 } else {
1348 cputime_to_timeval(p->utime, &prstatus->pr_utime);
1349 cputime_to_timeval(p->stime, &prstatus->pr_stime);
1350 }
1351 cputime_to_timeval(p->signal->cutime, &prstatus->pr_cutime);
1352 cputime_to_timeval(p->signal->cstime, &prstatus->pr_cstime);
1353}
1354
1355static int fill_psinfo(struct elf_prpsinfo *psinfo, struct task_struct *p,
1356 struct mm_struct *mm)
1357{
Greg Kroah-Hartmana84a5052005-05-11 00:10:44 -07001358 unsigned int i, len;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001359
1360 /* first copy the parameters from user space */
1361 memset(psinfo, 0, sizeof(struct elf_prpsinfo));
1362
1363 len = mm->arg_end - mm->arg_start;
1364 if (len >= ELF_PRARGSZ)
1365 len = ELF_PRARGSZ-1;
1366 if (copy_from_user(&psinfo->pr_psargs,
1367 (const char __user *)mm->arg_start, len))
1368 return -EFAULT;
1369 for(i = 0; i < len; i++)
1370 if (psinfo->pr_psargs[i] == 0)
1371 psinfo->pr_psargs[i] = ' ';
1372 psinfo->pr_psargs[len] = 0;
1373
1374 psinfo->pr_pid = p->pid;
1375 psinfo->pr_ppid = p->parent->pid;
1376 psinfo->pr_pgrp = process_group(p);
Cedric Le Goater937949d2006-12-08 02:37:54 -08001377 psinfo->pr_sid = process_session(p);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001378
1379 i = p->state ? ffz(~p->state) + 1 : 0;
1380 psinfo->pr_state = i;
Carsten Otte55148542006-03-25 03:08:22 -08001381 psinfo->pr_sname = (i > 5) ? '.' : "RSDTZW"[i];
Linus Torvalds1da177e2005-04-16 15:20:36 -07001382 psinfo->pr_zomb = psinfo->pr_sname == 'Z';
1383 psinfo->pr_nice = task_nice(p);
1384 psinfo->pr_flag = p->flags;
1385 SET_UID(psinfo->pr_uid, p->uid);
1386 SET_GID(psinfo->pr_gid, p->gid);
1387 strncpy(psinfo->pr_fname, p->comm, sizeof(psinfo->pr_fname));
1388
1389 return 0;
1390}
1391
1392/* Here is the structure in which status of each thread is captured. */
1393struct elf_thread_status
1394{
1395 struct list_head list;
1396 struct elf_prstatus prstatus; /* NT_PRSTATUS */
1397 elf_fpregset_t fpu; /* NT_PRFPREG */
1398 struct task_struct *thread;
1399#ifdef ELF_CORE_COPY_XFPREGS
1400 elf_fpxregset_t xfpu; /* NT_PRXFPREG */
1401#endif
1402 struct memelfnote notes[3];
1403 int num_notes;
1404};
1405
1406/*
1407 * In order to add the specific thread information for the elf file format,
Jesper Juhlf4e5cc22006-06-23 02:05:35 -07001408 * we need to keep a linked list of every threads pr_status and then create
1409 * a single section for them in the final core file.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001410 */
1411static int elf_dump_thread_status(long signr, struct elf_thread_status *t)
1412{
1413 int sz = 0;
1414 struct task_struct *p = t->thread;
1415 t->num_notes = 0;
1416
1417 fill_prstatus(&t->prstatus, p, signr);
1418 elf_core_copy_task_regs(p, &t->prstatus.pr_reg);
1419
Jesper Juhlf4e5cc22006-06-23 02:05:35 -07001420 fill_note(&t->notes[0], "CORE", NT_PRSTATUS, sizeof(t->prstatus),
1421 &(t->prstatus));
Linus Torvalds1da177e2005-04-16 15:20:36 -07001422 t->num_notes++;
1423 sz += notesize(&t->notes[0]);
1424
Jesper Juhlf4e5cc22006-06-23 02:05:35 -07001425 if ((t->prstatus.pr_fpvalid = elf_core_copy_task_fpregs(p, NULL,
1426 &t->fpu))) {
1427 fill_note(&t->notes[1], "CORE", NT_PRFPREG, sizeof(t->fpu),
1428 &(t->fpu));
Linus Torvalds1da177e2005-04-16 15:20:36 -07001429 t->num_notes++;
1430 sz += notesize(&t->notes[1]);
1431 }
1432
1433#ifdef ELF_CORE_COPY_XFPREGS
1434 if (elf_core_copy_task_xfpregs(p, &t->xfpu)) {
Jesper Juhlf4e5cc22006-06-23 02:05:35 -07001435 fill_note(&t->notes[2], "LINUX", NT_PRXFPREG, sizeof(t->xfpu),
1436 &t->xfpu);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001437 t->num_notes++;
1438 sz += notesize(&t->notes[2]);
1439 }
1440#endif
1441 return sz;
1442}
1443
Roland McGrathf47aef52007-01-26 00:56:49 -08001444static struct vm_area_struct *first_vma(struct task_struct *tsk,
1445 struct vm_area_struct *gate_vma)
1446{
1447 struct vm_area_struct *ret = tsk->mm->mmap;
1448
1449 if (ret)
1450 return ret;
1451 return gate_vma;
1452}
1453/*
1454 * Helper function for iterating across a vma list. It ensures that the caller
1455 * will visit `gate_vma' prior to terminating the search.
1456 */
1457static struct vm_area_struct *next_vma(struct vm_area_struct *this_vma,
1458 struct vm_area_struct *gate_vma)
1459{
1460 struct vm_area_struct *ret;
1461
1462 ret = this_vma->vm_next;
1463 if (ret)
1464 return ret;
1465 if (this_vma == gate_vma)
1466 return NULL;
1467 return gate_vma;
1468}
1469
Linus Torvalds1da177e2005-04-16 15:20:36 -07001470/*
1471 * Actual dumper
1472 *
1473 * This is a two-pass process; first we find the offsets of the bits,
1474 * and then they are actually written out. If we run out of core limit
1475 * we just truncate.
1476 */
Jesper Juhlf4e5cc22006-06-23 02:05:35 -07001477static int elf_core_dump(long signr, struct pt_regs *regs, struct file *file)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001478{
1479#define NUM_NOTES 6
1480 int has_dumped = 0;
1481 mm_segment_t fs;
1482 int segs;
1483 size_t size = 0;
1484 int i;
Roland McGrathf47aef52007-01-26 00:56:49 -08001485 struct vm_area_struct *vma, *gate_vma;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001486 struct elfhdr *elf = NULL;
Andi Kleend025c9d2006-09-30 23:29:28 -07001487 loff_t offset = 0, dataoff, foffset;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001488 unsigned long limit = current->signal->rlim[RLIMIT_CORE].rlim_cur;
1489 int numnote;
1490 struct memelfnote *notes = NULL;
1491 struct elf_prstatus *prstatus = NULL; /* NT_PRSTATUS */
1492 struct elf_prpsinfo *psinfo = NULL; /* NT_PRPSINFO */
1493 struct task_struct *g, *p;
1494 LIST_HEAD(thread_list);
1495 struct list_head *t;
1496 elf_fpregset_t *fpu = NULL;
1497#ifdef ELF_CORE_COPY_XFPREGS
1498 elf_fpxregset_t *xfpu = NULL;
1499#endif
1500 int thread_status_size = 0;
1501 elf_addr_t *auxv;
Michael Ellermanef7320e2007-07-06 02:39:49 -07001502#ifdef ELF_CORE_WRITE_EXTRA_NOTES
1503 int extra_notes_size;
1504#endif
Linus Torvalds1da177e2005-04-16 15:20:36 -07001505
1506 /*
1507 * We no longer stop all VM operations.
1508 *
Jesper Juhlf4e5cc22006-06-23 02:05:35 -07001509 * This is because those proceses that could possibly change map_count
1510 * or the mmap / vma pages are now blocked in do_exit on current
1511 * finishing this core dump.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001512 *
1513 * Only ptrace can touch these memory addresses, but it doesn't change
Jesper Juhlf4e5cc22006-06-23 02:05:35 -07001514 * the map_count or the pages allocated. So no possibility of crashing
Linus Torvalds1da177e2005-04-16 15:20:36 -07001515 * exists while dumping the mm->vm_next areas to the core file.
1516 */
1517
1518 /* alloc memory for large data structures: too large to be on stack */
1519 elf = kmalloc(sizeof(*elf), GFP_KERNEL);
1520 if (!elf)
1521 goto cleanup;
1522 prstatus = kmalloc(sizeof(*prstatus), GFP_KERNEL);
1523 if (!prstatus)
1524 goto cleanup;
1525 psinfo = kmalloc(sizeof(*psinfo), GFP_KERNEL);
1526 if (!psinfo)
1527 goto cleanup;
1528 notes = kmalloc(NUM_NOTES * sizeof(struct memelfnote), GFP_KERNEL);
1529 if (!notes)
1530 goto cleanup;
1531 fpu = kmalloc(sizeof(*fpu), GFP_KERNEL);
1532 if (!fpu)
1533 goto cleanup;
1534#ifdef ELF_CORE_COPY_XFPREGS
1535 xfpu = kmalloc(sizeof(*xfpu), GFP_KERNEL);
1536 if (!xfpu)
1537 goto cleanup;
1538#endif
1539
1540 if (signr) {
1541 struct elf_thread_status *tmp;
Oleg Nesterov486ccb02006-09-29 02:00:24 -07001542 rcu_read_lock();
Linus Torvalds1da177e2005-04-16 15:20:36 -07001543 do_each_thread(g,p)
1544 if (current->mm == p->mm && current != p) {
Oliver Neukum11b0b5a2006-03-25 03:08:13 -08001545 tmp = kzalloc(sizeof(*tmp), GFP_ATOMIC);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001546 if (!tmp) {
Oleg Nesterov486ccb02006-09-29 02:00:24 -07001547 rcu_read_unlock();
Linus Torvalds1da177e2005-04-16 15:20:36 -07001548 goto cleanup;
1549 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001550 tmp->thread = p;
1551 list_add(&tmp->list, &thread_list);
1552 }
1553 while_each_thread(g,p);
Oleg Nesterov486ccb02006-09-29 02:00:24 -07001554 rcu_read_unlock();
Linus Torvalds1da177e2005-04-16 15:20:36 -07001555 list_for_each(t, &thread_list) {
1556 struct elf_thread_status *tmp;
1557 int sz;
1558
1559 tmp = list_entry(t, struct elf_thread_status, list);
1560 sz = elf_dump_thread_status(signr, tmp);
1561 thread_status_size += sz;
1562 }
1563 }
1564 /* now collect the dump for the current */
1565 memset(prstatus, 0, sizeof(*prstatus));
1566 fill_prstatus(prstatus, current, signr);
1567 elf_core_copy_regs(&prstatus->pr_reg, regs);
1568
1569 segs = current->mm->map_count;
1570#ifdef ELF_CORE_EXTRA_PHDRS
1571 segs += ELF_CORE_EXTRA_PHDRS;
1572#endif
1573
Roland McGrathf47aef52007-01-26 00:56:49 -08001574 gate_vma = get_gate_vma(current);
1575 if (gate_vma != NULL)
1576 segs++;
1577
Linus Torvalds1da177e2005-04-16 15:20:36 -07001578 /* Set up header */
Jesper Juhlf4e5cc22006-06-23 02:05:35 -07001579 fill_elf_header(elf, segs + 1); /* including notes section */
Linus Torvalds1da177e2005-04-16 15:20:36 -07001580
1581 has_dumped = 1;
1582 current->flags |= PF_DUMPCORE;
1583
1584 /*
1585 * Set up the notes in similar form to SVR4 core dumps made
1586 * with info from their /proc.
1587 */
1588
Jesper Juhlf4e5cc22006-06-23 02:05:35 -07001589 fill_note(notes + 0, "CORE", NT_PRSTATUS, sizeof(*prstatus), prstatus);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001590 fill_psinfo(psinfo, current->group_leader, current->mm);
Jesper Juhlf4e5cc22006-06-23 02:05:35 -07001591 fill_note(notes + 1, "CORE", NT_PRPSINFO, sizeof(*psinfo), psinfo);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001592
Eric W. Biedermana9289722005-10-30 15:02:08 -08001593 numnote = 2;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001594
Jesper Juhlf4e5cc22006-06-23 02:05:35 -07001595 auxv = (elf_addr_t *)current->mm->saved_auxv;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001596
1597 i = 0;
1598 do
1599 i += 2;
1600 while (auxv[i - 2] != AT_NULL);
1601 fill_note(&notes[numnote++], "CORE", NT_AUXV,
Jesper Juhlf4e5cc22006-06-23 02:05:35 -07001602 i * sizeof(elf_addr_t), auxv);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001603
1604 /* Try to dump the FPU. */
Jesper Juhlf4e5cc22006-06-23 02:05:35 -07001605 if ((prstatus->pr_fpvalid =
1606 elf_core_copy_task_fpregs(current, regs, fpu)))
Linus Torvalds1da177e2005-04-16 15:20:36 -07001607 fill_note(notes + numnote++,
1608 "CORE", NT_PRFPREG, sizeof(*fpu), fpu);
1609#ifdef ELF_CORE_COPY_XFPREGS
1610 if (elf_core_copy_task_xfpregs(current, xfpu))
1611 fill_note(notes + numnote++,
1612 "LINUX", NT_PRXFPREG, sizeof(*xfpu), xfpu);
1613#endif
1614
1615 fs = get_fs();
1616 set_fs(KERNEL_DS);
1617
1618 DUMP_WRITE(elf, sizeof(*elf));
1619 offset += sizeof(*elf); /* Elf header */
Petr Vandroveca7a0d862006-10-13 18:42:07 +02001620 offset += (segs + 1) * sizeof(struct elf_phdr); /* Program headers */
1621 foffset = offset;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001622
1623 /* Write notes phdr entry */
1624 {
1625 struct elf_phdr phdr;
1626 int sz = 0;
1627
1628 for (i = 0; i < numnote; i++)
1629 sz += notesize(notes + i);
1630
1631 sz += thread_status_size;
1632
Dwayne Grant McConnellbf1ab972006-11-23 00:46:37 +01001633#ifdef ELF_CORE_WRITE_EXTRA_NOTES
Michael Ellermanef7320e2007-07-06 02:39:49 -07001634 extra_notes_size = ELF_CORE_EXTRA_NOTES_SIZE;
1635 sz += extra_notes_size;
Dwayne Grant McConnellbf1ab972006-11-23 00:46:37 +01001636#endif
1637
Linus Torvalds1da177e2005-04-16 15:20:36 -07001638 fill_elf_note_phdr(&phdr, sz, offset);
1639 offset += sz;
1640 DUMP_WRITE(&phdr, sizeof(phdr));
1641 }
1642
Linus Torvalds1da177e2005-04-16 15:20:36 -07001643 dataoff = offset = roundup(offset, ELF_EXEC_PAGESIZE);
1644
1645 /* Write program headers for segments dump */
Roland McGrathf47aef52007-01-26 00:56:49 -08001646 for (vma = first_vma(current, gate_vma); vma != NULL;
1647 vma = next_vma(vma, gate_vma)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001648 struct elf_phdr phdr;
1649 size_t sz;
1650
1651 sz = vma->vm_end - vma->vm_start;
1652
1653 phdr.p_type = PT_LOAD;
1654 phdr.p_offset = offset;
1655 phdr.p_vaddr = vma->vm_start;
1656 phdr.p_paddr = 0;
1657 phdr.p_filesz = maydump(vma) ? sz : 0;
1658 phdr.p_memsz = sz;
1659 offset += phdr.p_filesz;
1660 phdr.p_flags = vma->vm_flags & VM_READ ? PF_R : 0;
Jesper Juhlf4e5cc22006-06-23 02:05:35 -07001661 if (vma->vm_flags & VM_WRITE)
1662 phdr.p_flags |= PF_W;
1663 if (vma->vm_flags & VM_EXEC)
1664 phdr.p_flags |= PF_X;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001665 phdr.p_align = ELF_EXEC_PAGESIZE;
1666
1667 DUMP_WRITE(&phdr, sizeof(phdr));
1668 }
1669
1670#ifdef ELF_CORE_WRITE_EXTRA_PHDRS
1671 ELF_CORE_WRITE_EXTRA_PHDRS;
1672#endif
1673
1674 /* write out the notes section */
1675 for (i = 0; i < numnote; i++)
Andi Kleend025c9d2006-09-30 23:29:28 -07001676 if (!writenote(notes + i, file, &foffset))
Linus Torvalds1da177e2005-04-16 15:20:36 -07001677 goto end_coredump;
1678
Dwayne Grant McConnellbf1ab972006-11-23 00:46:37 +01001679#ifdef ELF_CORE_WRITE_EXTRA_NOTES
1680 ELF_CORE_WRITE_EXTRA_NOTES;
Michael Ellermanef7320e2007-07-06 02:39:49 -07001681 foffset += extra_notes_size;
Dwayne Grant McConnellbf1ab972006-11-23 00:46:37 +01001682#endif
1683
Linus Torvalds1da177e2005-04-16 15:20:36 -07001684 /* write out the thread status notes section */
1685 list_for_each(t, &thread_list) {
Jesper Juhlf4e5cc22006-06-23 02:05:35 -07001686 struct elf_thread_status *tmp =
1687 list_entry(t, struct elf_thread_status, list);
1688
Linus Torvalds1da177e2005-04-16 15:20:36 -07001689 for (i = 0; i < tmp->num_notes; i++)
Andi Kleend025c9d2006-09-30 23:29:28 -07001690 if (!writenote(&tmp->notes[i], file, &foffset))
Linus Torvalds1da177e2005-04-16 15:20:36 -07001691 goto end_coredump;
1692 }
Andi Kleend025c9d2006-09-30 23:29:28 -07001693
1694 /* Align to page */
1695 DUMP_SEEK(dataoff - foffset);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001696
Roland McGrathf47aef52007-01-26 00:56:49 -08001697 for (vma = first_vma(current, gate_vma); vma != NULL;
1698 vma = next_vma(vma, gate_vma)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001699 unsigned long addr;
1700
1701 if (!maydump(vma))
1702 continue;
1703
1704 for (addr = vma->vm_start;
1705 addr < vma->vm_end;
1706 addr += PAGE_SIZE) {
Jesper Juhlf4e5cc22006-06-23 02:05:35 -07001707 struct page *page;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001708 struct vm_area_struct *vma;
1709
1710 if (get_user_pages(current, current->mm, addr, 1, 0, 1,
1711 &page, &vma) <= 0) {
Andi Kleend025c9d2006-09-30 23:29:28 -07001712 DUMP_SEEK(PAGE_SIZE);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001713 } else {
1714 if (page == ZERO_PAGE(addr)) {
Brian Pomerantz03221702007-04-01 23:49:41 -07001715 if (!dump_seek(file, PAGE_SIZE)) {
1716 page_cache_release(page);
1717 goto end_coredump;
1718 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001719 } else {
1720 void *kaddr;
Jesper Juhlf4e5cc22006-06-23 02:05:35 -07001721 flush_cache_page(vma, addr,
1722 page_to_pfn(page));
Linus Torvalds1da177e2005-04-16 15:20:36 -07001723 kaddr = kmap(page);
1724 if ((size += PAGE_SIZE) > limit ||
1725 !dump_write(file, kaddr,
1726 PAGE_SIZE)) {
1727 kunmap(page);
1728 page_cache_release(page);
1729 goto end_coredump;
1730 }
1731 kunmap(page);
1732 }
1733 page_cache_release(page);
1734 }
1735 }
1736 }
1737
1738#ifdef ELF_CORE_WRITE_EXTRA_DATA
1739 ELF_CORE_WRITE_EXTRA_DATA;
1740#endif
1741
Linus Torvalds1da177e2005-04-16 15:20:36 -07001742end_coredump:
1743 set_fs(fs);
1744
1745cleanup:
Jesper Juhl74da6cd2006-01-11 01:51:26 +01001746 while (!list_empty(&thread_list)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001747 struct list_head *tmp = thread_list.next;
1748 list_del(tmp);
1749 kfree(list_entry(tmp, struct elf_thread_status, list));
1750 }
1751
1752 kfree(elf);
1753 kfree(prstatus);
1754 kfree(psinfo);
1755 kfree(notes);
1756 kfree(fpu);
1757#ifdef ELF_CORE_COPY_XFPREGS
1758 kfree(xfpu);
1759#endif
1760 return has_dumped;
1761#undef NUM_NOTES
1762}
1763
1764#endif /* USE_ELF_CORE_DUMP */
1765
1766static int __init init_elf_binfmt(void)
1767{
1768 return register_binfmt(&elf_format);
1769}
1770
1771static void __exit exit_elf_binfmt(void)
1772{
1773 /* Remove the COFF and ELF loaders. */
1774 unregister_binfmt(&elf_format);
1775}
1776
1777core_initcall(init_elf_binfmt);
1778module_exit(exit_elf_binfmt);
1779MODULE_LICENSE("GPL");