blob: 51db1182b27e4470edbc6945574aa1158a110bea [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>
34#include <linux/smp_lock.h>
35#include <linux/compiler.h>
36#include <linux/highmem.h>
37#include <linux/pagemap.h>
38#include <linux/security.h>
39#include <linux/syscalls.h>
40#include <linux/random.h>
Jesper Juhlf4e5cc22006-06-23 02:05:35 -070041#include <linux/elf.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
510#define STACK_RND_MASK 0x7ff /* with 4K pages 8MB of VA */
511#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);
874 goto out_free_dentry;
875 }
876
877 if (!load_addr_set) {
878 load_addr_set = 1;
879 load_addr = (elf_ppnt->p_vaddr - elf_ppnt->p_offset);
880 if (loc->elf_ex.e_type == ET_DYN) {
881 load_bias += error -
882 ELF_PAGESTART(load_bias + vaddr);
883 load_addr += load_bias;
884 reloc_func_desc = load_bias;
885 }
886 }
887 k = elf_ppnt->p_vaddr;
Jesper Juhlf4e5cc22006-06-23 02:05:35 -0700888 if (k < start_code)
889 start_code = k;
890 if (start_data < k)
891 start_data = k;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700892
893 /*
894 * Check to see if the section's size will overflow the
895 * allowed task size. Note that p_filesz must always be
896 * <= p_memsz so it is only necessary to check p_memsz.
897 */
Chuck Ebbertce510592006-07-03 00:24:14 -0700898 if (BAD_ADDR(k) || elf_ppnt->p_filesz > elf_ppnt->p_memsz ||
Linus Torvalds1da177e2005-04-16 15:20:36 -0700899 elf_ppnt->p_memsz > TASK_SIZE ||
900 TASK_SIZE - elf_ppnt->p_memsz < k) {
Jesper Juhlf4e5cc22006-06-23 02:05:35 -0700901 /* set_brk can never work. Avoid overflows. */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700902 send_sig(SIGKILL, current, 0);
903 goto out_free_dentry;
904 }
905
906 k = elf_ppnt->p_vaddr + elf_ppnt->p_filesz;
907
908 if (k > elf_bss)
909 elf_bss = k;
910 if ((elf_ppnt->p_flags & PF_X) && end_code < k)
911 end_code = k;
912 if (end_data < k)
913 end_data = k;
914 k = elf_ppnt->p_vaddr + elf_ppnt->p_memsz;
915 if (k > elf_brk)
916 elf_brk = k;
917 }
918
919 loc->elf_ex.e_entry += load_bias;
920 elf_bss += load_bias;
921 elf_brk += load_bias;
922 start_code += load_bias;
923 end_code += load_bias;
924 start_data += load_bias;
925 end_data += load_bias;
926
927 /* Calling set_brk effectively mmaps the pages that we need
928 * for the bss and break sections. We must do this before
929 * mapping in the interpreter, to make sure it doesn't wind
930 * up getting placed where the bss needs to go.
931 */
932 retval = set_brk(elf_bss, elf_brk);
933 if (retval) {
934 send_sig(SIGKILL, current, 0);
935 goto out_free_dentry;
936 }
akpm@osdl.org6de50512005-10-11 08:29:08 -0700937 if (likely(elf_bss != elf_brk) && unlikely(padzero(elf_bss))) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700938 send_sig(SIGSEGV, current, 0);
939 retval = -EFAULT; /* Nobody gets to see this, but.. */
940 goto out_free_dentry;
941 }
942
943 if (elf_interpreter) {
944 if (interpreter_type == INTERPRETER_AOUT)
945 elf_entry = load_aout_interp(&loc->interp_ex,
946 interpreter);
947 else
948 elf_entry = load_elf_interp(&loc->interp_elf_ex,
949 interpreter,
950 &interp_load_addr);
951 if (BAD_ADDR(elf_entry)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700952 force_sig(SIGSEGV, current);
Chuck Ebbertce510592006-07-03 00:24:14 -0700953 retval = IS_ERR((void *)elf_entry) ?
954 (int)elf_entry : -EINVAL;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700955 goto out_free_dentry;
956 }
957 reloc_func_desc = interp_load_addr;
958
959 allow_write_access(interpreter);
960 fput(interpreter);
961 kfree(elf_interpreter);
962 } else {
963 elf_entry = loc->elf_ex.e_entry;
Suresh Siddha5342fba2006-02-26 04:18:28 +0100964 if (BAD_ADDR(elf_entry)) {
Chuck Ebbertce510592006-07-03 00:24:14 -0700965 force_sig(SIGSEGV, current);
966 retval = -EINVAL;
Suresh Siddha5342fba2006-02-26 04:18:28 +0100967 goto out_free_dentry;
968 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700969 }
970
971 kfree(elf_phdata);
972
973 if (interpreter_type != INTERPRETER_AOUT)
974 sys_close(elf_exec_fileno);
975
976 set_binfmt(&elf_format);
977
Benjamin Herrenschmidt547ee842005-04-16 15:24:35 -0700978#ifdef ARCH_HAS_SETUP_ADDITIONAL_PAGES
979 retval = arch_setup_additional_pages(bprm, executable_stack);
980 if (retval < 0) {
981 send_sig(SIGKILL, current, 0);
Roland McGrath18c8baf2005-04-28 15:17:19 -0700982 goto out;
Benjamin Herrenschmidt547ee842005-04-16 15:24:35 -0700983 }
984#endif /* ARCH_HAS_SETUP_ADDITIONAL_PAGES */
985
Linus Torvalds1da177e2005-04-16 15:20:36 -0700986 compute_creds(bprm);
987 current->flags &= ~PF_FORKNOEXEC;
Jesper Juhlf4e5cc22006-06-23 02:05:35 -0700988 create_elf_tables(bprm, &loc->elf_ex,
989 (interpreter_type == INTERPRETER_AOUT),
990 load_addr, interp_load_addr);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700991 /* N.B. passed_fileno might not be initialized? */
992 if (interpreter_type == INTERPRETER_AOUT)
993 current->mm->arg_start += strlen(passed_fileno) + 1;
994 current->mm->end_code = end_code;
995 current->mm->start_code = start_code;
996 current->mm->start_data = start_data;
997 current->mm->end_data = end_data;
998 current->mm->start_stack = bprm->p;
999
1000 if (current->personality & MMAP_PAGE_ZERO) {
1001 /* Why this, you ask??? Well SVr4 maps page 0 as read-only,
1002 and some applications "depend" upon this behavior.
1003 Since we do not have the power to recompile these, we
Jesper Juhlf4e5cc22006-06-23 02:05:35 -07001004 emulate the SVr4 behavior. Sigh. */
Linus Torvalds1da177e2005-04-16 15:20:36 -07001005 down_write(&current->mm->mmap_sem);
1006 error = do_mmap(NULL, 0, PAGE_SIZE, PROT_READ | PROT_EXEC,
1007 MAP_FIXED | MAP_PRIVATE, 0);
1008 up_write(&current->mm->mmap_sem);
1009 }
1010
1011#ifdef ELF_PLAT_INIT
1012 /*
1013 * The ABI may specify that certain registers be set up in special
1014 * ways (on i386 %edx is the address of a DT_FINI function, for
1015 * example. In addition, it may also specify (eg, PowerPC64 ELF)
1016 * that the e_entry field is the address of the function descriptor
1017 * for the startup routine, rather than the address of the startup
1018 * routine itself. This macro performs whatever initialization to
1019 * the regs structure is required as well as any relocations to the
1020 * function descriptor entries when executing dynamically links apps.
1021 */
1022 ELF_PLAT_INIT(regs, reloc_func_desc);
1023#endif
1024
1025 start_thread(regs, elf_entry, bprm->p);
1026 if (unlikely(current->ptrace & PT_PTRACED)) {
1027 if (current->ptrace & PT_TRACE_EXEC)
1028 ptrace_notify ((PTRACE_EVENT_EXEC << 8) | SIGTRAP);
1029 else
1030 send_sig(SIGTRAP, current, 0);
1031 }
1032 retval = 0;
1033out:
1034 kfree(loc);
1035out_ret:
1036 return retval;
1037
1038 /* error cleanup */
1039out_free_dentry:
1040 allow_write_access(interpreter);
1041 if (interpreter)
1042 fput(interpreter);
1043out_free_interp:
Jesper Juhlf99d49a2005-11-07 01:01:34 -08001044 kfree(elf_interpreter);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001045out_free_file:
1046 sys_close(elf_exec_fileno);
1047out_free_fh:
Kirill Korotaev3b9b8ab2006-09-29 02:00:05 -07001048 if (files)
1049 reset_files_struct(current, files);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001050out_free_ph:
1051 kfree(elf_phdata);
1052 goto out;
1053}
1054
1055/* This is really simpleminded and specialized - we are loading an
1056 a.out library that is given an ELF header. */
Linus Torvalds1da177e2005-04-16 15:20:36 -07001057static int load_elf_library(struct file *file)
1058{
1059 struct elf_phdr *elf_phdata;
1060 struct elf_phdr *eppnt;
1061 unsigned long elf_bss, bss, len;
1062 int retval, error, i, j;
1063 struct elfhdr elf_ex;
1064
1065 error = -ENOEXEC;
Jesper Juhlf4e5cc22006-06-23 02:05:35 -07001066 retval = kernel_read(file, 0, (char *)&elf_ex, sizeof(elf_ex));
Linus Torvalds1da177e2005-04-16 15:20:36 -07001067 if (retval != sizeof(elf_ex))
1068 goto out;
1069
1070 if (memcmp(elf_ex.e_ident, ELFMAG, SELFMAG) != 0)
1071 goto out;
1072
1073 /* First of all, some simple consistency checks */
1074 if (elf_ex.e_type != ET_EXEC || elf_ex.e_phnum > 2 ||
Jesper Juhlf4e5cc22006-06-23 02:05:35 -07001075 !elf_check_arch(&elf_ex) || !file->f_op || !file->f_op->mmap)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001076 goto out;
1077
1078 /* Now read in all of the header information */
1079
1080 j = sizeof(struct elf_phdr) * elf_ex.e_phnum;
1081 /* j < ELF_MIN_ALIGN because elf_ex.e_phnum <= 2 */
1082
1083 error = -ENOMEM;
1084 elf_phdata = kmalloc(j, GFP_KERNEL);
1085 if (!elf_phdata)
1086 goto out;
1087
1088 eppnt = elf_phdata;
1089 error = -ENOEXEC;
1090 retval = kernel_read(file, elf_ex.e_phoff, (char *)eppnt, j);
1091 if (retval != j)
1092 goto out_free_ph;
1093
1094 for (j = 0, i = 0; i<elf_ex.e_phnum; i++)
1095 if ((eppnt + i)->p_type == PT_LOAD)
1096 j++;
1097 if (j != 1)
1098 goto out_free_ph;
1099
1100 while (eppnt->p_type != PT_LOAD)
1101 eppnt++;
1102
1103 /* Now use mmap to map the library into memory. */
1104 down_write(&current->mm->mmap_sem);
1105 error = do_mmap(file,
1106 ELF_PAGESTART(eppnt->p_vaddr),
1107 (eppnt->p_filesz +
1108 ELF_PAGEOFFSET(eppnt->p_vaddr)),
1109 PROT_READ | PROT_WRITE | PROT_EXEC,
1110 MAP_FIXED | MAP_PRIVATE | MAP_DENYWRITE,
1111 (eppnt->p_offset -
1112 ELF_PAGEOFFSET(eppnt->p_vaddr)));
1113 up_write(&current->mm->mmap_sem);
1114 if (error != ELF_PAGESTART(eppnt->p_vaddr))
1115 goto out_free_ph;
1116
1117 elf_bss = eppnt->p_vaddr + eppnt->p_filesz;
1118 if (padzero(elf_bss)) {
1119 error = -EFAULT;
1120 goto out_free_ph;
1121 }
1122
Jesper Juhlf4e5cc22006-06-23 02:05:35 -07001123 len = ELF_PAGESTART(eppnt->p_filesz + eppnt->p_vaddr +
1124 ELF_MIN_ALIGN - 1);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001125 bss = eppnt->p_memsz + eppnt->p_vaddr;
1126 if (bss > len) {
1127 down_write(&current->mm->mmap_sem);
1128 do_brk(len, bss - len);
1129 up_write(&current->mm->mmap_sem);
1130 }
1131 error = 0;
1132
1133out_free_ph:
1134 kfree(elf_phdata);
1135out:
1136 return error;
1137}
1138
1139/*
1140 * Note that some platforms still use traditional core dumps and not
1141 * the ELF core dump. Each platform can select it as appropriate.
1142 */
Matt Mackall708e9a72006-01-08 01:05:25 -08001143#if defined(USE_ELF_CORE_DUMP) && defined(CONFIG_ELF_CORE)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001144
1145/*
1146 * ELF core dumper
1147 *
1148 * Modelled on fs/exec.c:aout_core_dump()
1149 * Jeremy Fitzhardinge <jeremy@sw.oz.au>
1150 */
1151/*
1152 * These are the only things you should do on a core-file: use only these
1153 * functions to write out all the necessary info.
1154 */
1155static int dump_write(struct file *file, const void *addr, int nr)
1156{
1157 return file->f_op->write(file, addr, nr, &file->f_pos) == nr;
1158}
1159
Daniel Jacobowitz5db92852005-06-15 22:26:34 -07001160static int dump_seek(struct file *file, loff_t off)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001161{
Andi Kleend025c9d2006-09-30 23:29:28 -07001162 if (file->f_op->llseek && file->f_op->llseek != no_llseek) {
Petr Vandrovec7f14daa2006-10-13 04:13:16 +02001163 if (file->f_op->llseek(file, off, SEEK_CUR) < 0)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001164 return 0;
Andi Kleend025c9d2006-09-30 23:29:28 -07001165 } else {
1166 char *buf = (char *)get_zeroed_page(GFP_KERNEL);
1167 if (!buf)
1168 return 0;
1169 while (off > 0) {
1170 unsigned long n = off;
1171 if (n > PAGE_SIZE)
1172 n = PAGE_SIZE;
1173 if (!dump_write(file, buf, n))
1174 return 0;
1175 off -= n;
1176 }
1177 free_page((unsigned long)buf);
1178 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001179 return 1;
1180}
1181
1182/*
1183 * Decide whether a segment is worth dumping; default is yes to be
1184 * sure (missing info is worse than too much; etc).
1185 * Personally I'd include everything, and use the coredump limit...
1186 *
1187 * I think we should skip something. But I am not sure how. H.J.
1188 */
1189static int maydump(struct vm_area_struct *vma)
1190{
Roland McGrathe5b97dd2007-01-26 00:56:48 -08001191 /* The vma can be set up to tell us the answer directly. */
1192 if (vma->vm_flags & VM_ALWAYSDUMP)
1193 return 1;
1194
Linus Torvalds1da177e2005-04-16 15:20:36 -07001195 /* Do not dump I/O mapped devices or special mappings */
1196 if (vma->vm_flags & (VM_IO | VM_RESERVED))
1197 return 0;
1198
Jesper Juhlf4e5cc22006-06-23 02:05:35 -07001199 /* Dump shared memory only if mapped from an anonymous file. */
Linus Torvalds1da177e2005-04-16 15:20:36 -07001200 if (vma->vm_flags & VM_SHARED)
Josef "Jeff" Sipek0f7fc9e2006-12-08 02:36:35 -08001201 return vma->vm_file->f_path.dentry->d_inode->i_nlink == 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001202
1203 /* If it hasn't been written to, don't write it out */
1204 if (!vma->anon_vma)
1205 return 0;
1206
1207 return 1;
1208}
1209
Linus Torvalds1da177e2005-04-16 15:20:36 -07001210/* An ELF note in memory */
1211struct memelfnote
1212{
1213 const char *name;
1214 int type;
1215 unsigned int datasz;
1216 void *data;
1217};
1218
1219static int notesize(struct memelfnote *en)
1220{
1221 int sz;
1222
1223 sz = sizeof(struct elf_note);
1224 sz += roundup(strlen(en->name) + 1, 4);
1225 sz += roundup(en->datasz, 4);
1226
1227 return sz;
1228}
1229
Andi Kleend025c9d2006-09-30 23:29:28 -07001230#define DUMP_WRITE(addr, nr, foffset) \
1231 do { if (!dump_write(file, (addr), (nr))) return 0; *foffset += (nr); } while(0)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001232
Andi Kleend025c9d2006-09-30 23:29:28 -07001233static int alignfile(struct file *file, loff_t *foffset)
1234{
Petr Vandroveca7a0d862006-10-13 18:42:07 +02001235 static const char buf[4] = { 0, };
Andi Kleend025c9d2006-09-30 23:29:28 -07001236 DUMP_WRITE(buf, roundup(*foffset, 4) - *foffset, foffset);
1237 return 1;
1238}
1239
1240static int writenote(struct memelfnote *men, struct file *file,
1241 loff_t *foffset)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001242{
1243 struct elf_note en;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001244 en.n_namesz = strlen(men->name) + 1;
1245 en.n_descsz = men->datasz;
1246 en.n_type = men->type;
1247
Andi Kleend025c9d2006-09-30 23:29:28 -07001248 DUMP_WRITE(&en, sizeof(en), foffset);
1249 DUMP_WRITE(men->name, en.n_namesz, foffset);
1250 if (!alignfile(file, foffset))
1251 return 0;
1252 DUMP_WRITE(men->data, men->datasz, foffset);
1253 if (!alignfile(file, foffset))
1254 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001255
1256 return 1;
1257}
1258#undef DUMP_WRITE
Linus Torvalds1da177e2005-04-16 15:20:36 -07001259
1260#define DUMP_WRITE(addr, nr) \
1261 if ((size += (nr)) > limit || !dump_write(file, (addr), (nr))) \
1262 goto end_coredump;
1263#define DUMP_SEEK(off) \
1264 if (!dump_seek(file, (off))) \
1265 goto end_coredump;
1266
Arjan van de Ven858119e2006-01-14 13:20:43 -08001267static void fill_elf_header(struct elfhdr *elf, int segs)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001268{
1269 memcpy(elf->e_ident, ELFMAG, SELFMAG);
1270 elf->e_ident[EI_CLASS] = ELF_CLASS;
1271 elf->e_ident[EI_DATA] = ELF_DATA;
1272 elf->e_ident[EI_VERSION] = EV_CURRENT;
1273 elf->e_ident[EI_OSABI] = ELF_OSABI;
1274 memset(elf->e_ident+EI_PAD, 0, EI_NIDENT-EI_PAD);
1275
1276 elf->e_type = ET_CORE;
1277 elf->e_machine = ELF_ARCH;
1278 elf->e_version = EV_CURRENT;
1279 elf->e_entry = 0;
1280 elf->e_phoff = sizeof(struct elfhdr);
1281 elf->e_shoff = 0;
1282 elf->e_flags = ELF_CORE_EFLAGS;
1283 elf->e_ehsize = sizeof(struct elfhdr);
1284 elf->e_phentsize = sizeof(struct elf_phdr);
1285 elf->e_phnum = segs;
1286 elf->e_shentsize = 0;
1287 elf->e_shnum = 0;
1288 elf->e_shstrndx = 0;
1289 return;
1290}
1291
Andrew Morton8d6b5eee2006-09-25 23:32:04 -07001292static void fill_elf_note_phdr(struct elf_phdr *phdr, int sz, loff_t offset)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001293{
1294 phdr->p_type = PT_NOTE;
1295 phdr->p_offset = offset;
1296 phdr->p_vaddr = 0;
1297 phdr->p_paddr = 0;
1298 phdr->p_filesz = sz;
1299 phdr->p_memsz = 0;
1300 phdr->p_flags = 0;
1301 phdr->p_align = 0;
1302 return;
1303}
1304
1305static void fill_note(struct memelfnote *note, const char *name, int type,
1306 unsigned int sz, void *data)
1307{
1308 note->name = name;
1309 note->type = type;
1310 note->datasz = sz;
1311 note->data = data;
1312 return;
1313}
1314
1315/*
Jesper Juhlf4e5cc22006-06-23 02:05:35 -07001316 * fill up all the fields in prstatus from the given task struct, except
1317 * registers which need to be filled up separately.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001318 */
1319static void fill_prstatus(struct elf_prstatus *prstatus,
Jesper Juhlf4e5cc22006-06-23 02:05:35 -07001320 struct task_struct *p, long signr)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001321{
1322 prstatus->pr_info.si_signo = prstatus->pr_cursig = signr;
1323 prstatus->pr_sigpend = p->pending.signal.sig[0];
1324 prstatus->pr_sighold = p->blocked.sig[0];
1325 prstatus->pr_pid = p->pid;
1326 prstatus->pr_ppid = p->parent->pid;
1327 prstatus->pr_pgrp = process_group(p);
Cedric Le Goater937949d2006-12-08 02:37:54 -08001328 prstatus->pr_sid = process_session(p);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001329 if (thread_group_leader(p)) {
1330 /*
1331 * This is the record for the group leader. Add in the
1332 * cumulative times of previous dead threads. This total
1333 * won't include the time of each live thread whose state
1334 * is included in the core dump. The final total reported
1335 * to our parent process when it calls wait4 will include
1336 * those sums as well as the little bit more time it takes
1337 * this and each other thread to finish dying after the
1338 * core dump synchronization phase.
1339 */
1340 cputime_to_timeval(cputime_add(p->utime, p->signal->utime),
1341 &prstatus->pr_utime);
1342 cputime_to_timeval(cputime_add(p->stime, p->signal->stime),
1343 &prstatus->pr_stime);
1344 } else {
1345 cputime_to_timeval(p->utime, &prstatus->pr_utime);
1346 cputime_to_timeval(p->stime, &prstatus->pr_stime);
1347 }
1348 cputime_to_timeval(p->signal->cutime, &prstatus->pr_cutime);
1349 cputime_to_timeval(p->signal->cstime, &prstatus->pr_cstime);
1350}
1351
1352static int fill_psinfo(struct elf_prpsinfo *psinfo, struct task_struct *p,
1353 struct mm_struct *mm)
1354{
Greg Kroah-Hartmana84a5052005-05-11 00:10:44 -07001355 unsigned int i, len;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001356
1357 /* first copy the parameters from user space */
1358 memset(psinfo, 0, sizeof(struct elf_prpsinfo));
1359
1360 len = mm->arg_end - mm->arg_start;
1361 if (len >= ELF_PRARGSZ)
1362 len = ELF_PRARGSZ-1;
1363 if (copy_from_user(&psinfo->pr_psargs,
1364 (const char __user *)mm->arg_start, len))
1365 return -EFAULT;
1366 for(i = 0; i < len; i++)
1367 if (psinfo->pr_psargs[i] == 0)
1368 psinfo->pr_psargs[i] = ' ';
1369 psinfo->pr_psargs[len] = 0;
1370
1371 psinfo->pr_pid = p->pid;
1372 psinfo->pr_ppid = p->parent->pid;
1373 psinfo->pr_pgrp = process_group(p);
Cedric Le Goater937949d2006-12-08 02:37:54 -08001374 psinfo->pr_sid = process_session(p);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001375
1376 i = p->state ? ffz(~p->state) + 1 : 0;
1377 psinfo->pr_state = i;
Carsten Otte55148542006-03-25 03:08:22 -08001378 psinfo->pr_sname = (i > 5) ? '.' : "RSDTZW"[i];
Linus Torvalds1da177e2005-04-16 15:20:36 -07001379 psinfo->pr_zomb = psinfo->pr_sname == 'Z';
1380 psinfo->pr_nice = task_nice(p);
1381 psinfo->pr_flag = p->flags;
1382 SET_UID(psinfo->pr_uid, p->uid);
1383 SET_GID(psinfo->pr_gid, p->gid);
1384 strncpy(psinfo->pr_fname, p->comm, sizeof(psinfo->pr_fname));
1385
1386 return 0;
1387}
1388
1389/* Here is the structure in which status of each thread is captured. */
1390struct elf_thread_status
1391{
1392 struct list_head list;
1393 struct elf_prstatus prstatus; /* NT_PRSTATUS */
1394 elf_fpregset_t fpu; /* NT_PRFPREG */
1395 struct task_struct *thread;
1396#ifdef ELF_CORE_COPY_XFPREGS
1397 elf_fpxregset_t xfpu; /* NT_PRXFPREG */
1398#endif
1399 struct memelfnote notes[3];
1400 int num_notes;
1401};
1402
1403/*
1404 * In order to add the specific thread information for the elf file format,
Jesper Juhlf4e5cc22006-06-23 02:05:35 -07001405 * we need to keep a linked list of every threads pr_status and then create
1406 * a single section for them in the final core file.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001407 */
1408static int elf_dump_thread_status(long signr, struct elf_thread_status *t)
1409{
1410 int sz = 0;
1411 struct task_struct *p = t->thread;
1412 t->num_notes = 0;
1413
1414 fill_prstatus(&t->prstatus, p, signr);
1415 elf_core_copy_task_regs(p, &t->prstatus.pr_reg);
1416
Jesper Juhlf4e5cc22006-06-23 02:05:35 -07001417 fill_note(&t->notes[0], "CORE", NT_PRSTATUS, sizeof(t->prstatus),
1418 &(t->prstatus));
Linus Torvalds1da177e2005-04-16 15:20:36 -07001419 t->num_notes++;
1420 sz += notesize(&t->notes[0]);
1421
Jesper Juhlf4e5cc22006-06-23 02:05:35 -07001422 if ((t->prstatus.pr_fpvalid = elf_core_copy_task_fpregs(p, NULL,
1423 &t->fpu))) {
1424 fill_note(&t->notes[1], "CORE", NT_PRFPREG, sizeof(t->fpu),
1425 &(t->fpu));
Linus Torvalds1da177e2005-04-16 15:20:36 -07001426 t->num_notes++;
1427 sz += notesize(&t->notes[1]);
1428 }
1429
1430#ifdef ELF_CORE_COPY_XFPREGS
1431 if (elf_core_copy_task_xfpregs(p, &t->xfpu)) {
Jesper Juhlf4e5cc22006-06-23 02:05:35 -07001432 fill_note(&t->notes[2], "LINUX", NT_PRXFPREG, sizeof(t->xfpu),
1433 &t->xfpu);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001434 t->num_notes++;
1435 sz += notesize(&t->notes[2]);
1436 }
1437#endif
1438 return sz;
1439}
1440
Roland McGrathf47aef52007-01-26 00:56:49 -08001441static struct vm_area_struct *first_vma(struct task_struct *tsk,
1442 struct vm_area_struct *gate_vma)
1443{
1444 struct vm_area_struct *ret = tsk->mm->mmap;
1445
1446 if (ret)
1447 return ret;
1448 return gate_vma;
1449}
1450/*
1451 * Helper function for iterating across a vma list. It ensures that the caller
1452 * will visit `gate_vma' prior to terminating the search.
1453 */
1454static struct vm_area_struct *next_vma(struct vm_area_struct *this_vma,
1455 struct vm_area_struct *gate_vma)
1456{
1457 struct vm_area_struct *ret;
1458
1459 ret = this_vma->vm_next;
1460 if (ret)
1461 return ret;
1462 if (this_vma == gate_vma)
1463 return NULL;
1464 return gate_vma;
1465}
1466
Linus Torvalds1da177e2005-04-16 15:20:36 -07001467/*
1468 * Actual dumper
1469 *
1470 * This is a two-pass process; first we find the offsets of the bits,
1471 * and then they are actually written out. If we run out of core limit
1472 * we just truncate.
1473 */
Jesper Juhlf4e5cc22006-06-23 02:05:35 -07001474static int elf_core_dump(long signr, struct pt_regs *regs, struct file *file)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001475{
1476#define NUM_NOTES 6
1477 int has_dumped = 0;
1478 mm_segment_t fs;
1479 int segs;
1480 size_t size = 0;
1481 int i;
Roland McGrathf47aef52007-01-26 00:56:49 -08001482 struct vm_area_struct *vma, *gate_vma;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001483 struct elfhdr *elf = NULL;
Andi Kleend025c9d2006-09-30 23:29:28 -07001484 loff_t offset = 0, dataoff, foffset;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001485 unsigned long limit = current->signal->rlim[RLIMIT_CORE].rlim_cur;
1486 int numnote;
1487 struct memelfnote *notes = NULL;
1488 struct elf_prstatus *prstatus = NULL; /* NT_PRSTATUS */
1489 struct elf_prpsinfo *psinfo = NULL; /* NT_PRPSINFO */
1490 struct task_struct *g, *p;
1491 LIST_HEAD(thread_list);
1492 struct list_head *t;
1493 elf_fpregset_t *fpu = NULL;
1494#ifdef ELF_CORE_COPY_XFPREGS
1495 elf_fpxregset_t *xfpu = NULL;
1496#endif
1497 int thread_status_size = 0;
1498 elf_addr_t *auxv;
1499
1500 /*
1501 * We no longer stop all VM operations.
1502 *
Jesper Juhlf4e5cc22006-06-23 02:05:35 -07001503 * This is because those proceses that could possibly change map_count
1504 * or the mmap / vma pages are now blocked in do_exit on current
1505 * finishing this core dump.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001506 *
1507 * Only ptrace can touch these memory addresses, but it doesn't change
Jesper Juhlf4e5cc22006-06-23 02:05:35 -07001508 * the map_count or the pages allocated. So no possibility of crashing
Linus Torvalds1da177e2005-04-16 15:20:36 -07001509 * exists while dumping the mm->vm_next areas to the core file.
1510 */
1511
1512 /* alloc memory for large data structures: too large to be on stack */
1513 elf = kmalloc(sizeof(*elf), GFP_KERNEL);
1514 if (!elf)
1515 goto cleanup;
1516 prstatus = kmalloc(sizeof(*prstatus), GFP_KERNEL);
1517 if (!prstatus)
1518 goto cleanup;
1519 psinfo = kmalloc(sizeof(*psinfo), GFP_KERNEL);
1520 if (!psinfo)
1521 goto cleanup;
1522 notes = kmalloc(NUM_NOTES * sizeof(struct memelfnote), GFP_KERNEL);
1523 if (!notes)
1524 goto cleanup;
1525 fpu = kmalloc(sizeof(*fpu), GFP_KERNEL);
1526 if (!fpu)
1527 goto cleanup;
1528#ifdef ELF_CORE_COPY_XFPREGS
1529 xfpu = kmalloc(sizeof(*xfpu), GFP_KERNEL);
1530 if (!xfpu)
1531 goto cleanup;
1532#endif
1533
1534 if (signr) {
1535 struct elf_thread_status *tmp;
Oleg Nesterov486ccb02006-09-29 02:00:24 -07001536 rcu_read_lock();
Linus Torvalds1da177e2005-04-16 15:20:36 -07001537 do_each_thread(g,p)
1538 if (current->mm == p->mm && current != p) {
Oliver Neukum11b0b5a2006-03-25 03:08:13 -08001539 tmp = kzalloc(sizeof(*tmp), GFP_ATOMIC);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001540 if (!tmp) {
Oleg Nesterov486ccb02006-09-29 02:00:24 -07001541 rcu_read_unlock();
Linus Torvalds1da177e2005-04-16 15:20:36 -07001542 goto cleanup;
1543 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001544 tmp->thread = p;
1545 list_add(&tmp->list, &thread_list);
1546 }
1547 while_each_thread(g,p);
Oleg Nesterov486ccb02006-09-29 02:00:24 -07001548 rcu_read_unlock();
Linus Torvalds1da177e2005-04-16 15:20:36 -07001549 list_for_each(t, &thread_list) {
1550 struct elf_thread_status *tmp;
1551 int sz;
1552
1553 tmp = list_entry(t, struct elf_thread_status, list);
1554 sz = elf_dump_thread_status(signr, tmp);
1555 thread_status_size += sz;
1556 }
1557 }
1558 /* now collect the dump for the current */
1559 memset(prstatus, 0, sizeof(*prstatus));
1560 fill_prstatus(prstatus, current, signr);
1561 elf_core_copy_regs(&prstatus->pr_reg, regs);
1562
1563 segs = current->mm->map_count;
1564#ifdef ELF_CORE_EXTRA_PHDRS
1565 segs += ELF_CORE_EXTRA_PHDRS;
1566#endif
1567
Roland McGrathf47aef52007-01-26 00:56:49 -08001568 gate_vma = get_gate_vma(current);
1569 if (gate_vma != NULL)
1570 segs++;
1571
Linus Torvalds1da177e2005-04-16 15:20:36 -07001572 /* Set up header */
Jesper Juhlf4e5cc22006-06-23 02:05:35 -07001573 fill_elf_header(elf, segs + 1); /* including notes section */
Linus Torvalds1da177e2005-04-16 15:20:36 -07001574
1575 has_dumped = 1;
1576 current->flags |= PF_DUMPCORE;
1577
1578 /*
1579 * Set up the notes in similar form to SVR4 core dumps made
1580 * with info from their /proc.
1581 */
1582
Jesper Juhlf4e5cc22006-06-23 02:05:35 -07001583 fill_note(notes + 0, "CORE", NT_PRSTATUS, sizeof(*prstatus), prstatus);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001584 fill_psinfo(psinfo, current->group_leader, current->mm);
Jesper Juhlf4e5cc22006-06-23 02:05:35 -07001585 fill_note(notes + 1, "CORE", NT_PRPSINFO, sizeof(*psinfo), psinfo);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001586
Eric W. Biedermana9289722005-10-30 15:02:08 -08001587 numnote = 2;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001588
Jesper Juhlf4e5cc22006-06-23 02:05:35 -07001589 auxv = (elf_addr_t *)current->mm->saved_auxv;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001590
1591 i = 0;
1592 do
1593 i += 2;
1594 while (auxv[i - 2] != AT_NULL);
1595 fill_note(&notes[numnote++], "CORE", NT_AUXV,
Jesper Juhlf4e5cc22006-06-23 02:05:35 -07001596 i * sizeof(elf_addr_t), auxv);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001597
1598 /* Try to dump the FPU. */
Jesper Juhlf4e5cc22006-06-23 02:05:35 -07001599 if ((prstatus->pr_fpvalid =
1600 elf_core_copy_task_fpregs(current, regs, fpu)))
Linus Torvalds1da177e2005-04-16 15:20:36 -07001601 fill_note(notes + numnote++,
1602 "CORE", NT_PRFPREG, sizeof(*fpu), fpu);
1603#ifdef ELF_CORE_COPY_XFPREGS
1604 if (elf_core_copy_task_xfpregs(current, xfpu))
1605 fill_note(notes + numnote++,
1606 "LINUX", NT_PRXFPREG, sizeof(*xfpu), xfpu);
1607#endif
1608
1609 fs = get_fs();
1610 set_fs(KERNEL_DS);
1611
1612 DUMP_WRITE(elf, sizeof(*elf));
1613 offset += sizeof(*elf); /* Elf header */
Petr Vandroveca7a0d862006-10-13 18:42:07 +02001614 offset += (segs + 1) * sizeof(struct elf_phdr); /* Program headers */
1615 foffset = offset;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001616
1617 /* Write notes phdr entry */
1618 {
1619 struct elf_phdr phdr;
1620 int sz = 0;
1621
1622 for (i = 0; i < numnote; i++)
1623 sz += notesize(notes + i);
1624
1625 sz += thread_status_size;
1626
Dwayne Grant McConnellbf1ab972006-11-23 00:46:37 +01001627#ifdef ELF_CORE_WRITE_EXTRA_NOTES
1628 sz += ELF_CORE_EXTRA_NOTES_SIZE;
1629#endif
1630
Linus Torvalds1da177e2005-04-16 15:20:36 -07001631 fill_elf_note_phdr(&phdr, sz, offset);
1632 offset += sz;
1633 DUMP_WRITE(&phdr, sizeof(phdr));
1634 }
1635
Linus Torvalds1da177e2005-04-16 15:20:36 -07001636 dataoff = offset = roundup(offset, ELF_EXEC_PAGESIZE);
1637
1638 /* Write program headers for segments dump */
Roland McGrathf47aef52007-01-26 00:56:49 -08001639 for (vma = first_vma(current, gate_vma); vma != NULL;
1640 vma = next_vma(vma, gate_vma)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001641 struct elf_phdr phdr;
1642 size_t sz;
1643
1644 sz = vma->vm_end - vma->vm_start;
1645
1646 phdr.p_type = PT_LOAD;
1647 phdr.p_offset = offset;
1648 phdr.p_vaddr = vma->vm_start;
1649 phdr.p_paddr = 0;
1650 phdr.p_filesz = maydump(vma) ? sz : 0;
1651 phdr.p_memsz = sz;
1652 offset += phdr.p_filesz;
1653 phdr.p_flags = vma->vm_flags & VM_READ ? PF_R : 0;
Jesper Juhlf4e5cc22006-06-23 02:05:35 -07001654 if (vma->vm_flags & VM_WRITE)
1655 phdr.p_flags |= PF_W;
1656 if (vma->vm_flags & VM_EXEC)
1657 phdr.p_flags |= PF_X;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001658 phdr.p_align = ELF_EXEC_PAGESIZE;
1659
1660 DUMP_WRITE(&phdr, sizeof(phdr));
1661 }
1662
1663#ifdef ELF_CORE_WRITE_EXTRA_PHDRS
1664 ELF_CORE_WRITE_EXTRA_PHDRS;
1665#endif
1666
1667 /* write out the notes section */
1668 for (i = 0; i < numnote; i++)
Andi Kleend025c9d2006-09-30 23:29:28 -07001669 if (!writenote(notes + i, file, &foffset))
Linus Torvalds1da177e2005-04-16 15:20:36 -07001670 goto end_coredump;
1671
Dwayne Grant McConnellbf1ab972006-11-23 00:46:37 +01001672#ifdef ELF_CORE_WRITE_EXTRA_NOTES
1673 ELF_CORE_WRITE_EXTRA_NOTES;
1674#endif
1675
Linus Torvalds1da177e2005-04-16 15:20:36 -07001676 /* write out the thread status notes section */
1677 list_for_each(t, &thread_list) {
Jesper Juhlf4e5cc22006-06-23 02:05:35 -07001678 struct elf_thread_status *tmp =
1679 list_entry(t, struct elf_thread_status, list);
1680
Linus Torvalds1da177e2005-04-16 15:20:36 -07001681 for (i = 0; i < tmp->num_notes; i++)
Andi Kleend025c9d2006-09-30 23:29:28 -07001682 if (!writenote(&tmp->notes[i], file, &foffset))
Linus Torvalds1da177e2005-04-16 15:20:36 -07001683 goto end_coredump;
1684 }
Andi Kleend025c9d2006-09-30 23:29:28 -07001685
1686 /* Align to page */
1687 DUMP_SEEK(dataoff - foffset);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001688
Roland McGrathf47aef52007-01-26 00:56:49 -08001689 for (vma = first_vma(current, gate_vma); vma != NULL;
1690 vma = next_vma(vma, gate_vma)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001691 unsigned long addr;
1692
1693 if (!maydump(vma))
1694 continue;
1695
1696 for (addr = vma->vm_start;
1697 addr < vma->vm_end;
1698 addr += PAGE_SIZE) {
Jesper Juhlf4e5cc22006-06-23 02:05:35 -07001699 struct page *page;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001700 struct vm_area_struct *vma;
1701
1702 if (get_user_pages(current, current->mm, addr, 1, 0, 1,
1703 &page, &vma) <= 0) {
Andi Kleend025c9d2006-09-30 23:29:28 -07001704 DUMP_SEEK(PAGE_SIZE);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001705 } else {
1706 if (page == ZERO_PAGE(addr)) {
Andi Kleend025c9d2006-09-30 23:29:28 -07001707 DUMP_SEEK(PAGE_SIZE);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001708 } else {
1709 void *kaddr;
Jesper Juhlf4e5cc22006-06-23 02:05:35 -07001710 flush_cache_page(vma, addr,
1711 page_to_pfn(page));
Linus Torvalds1da177e2005-04-16 15:20:36 -07001712 kaddr = kmap(page);
1713 if ((size += PAGE_SIZE) > limit ||
1714 !dump_write(file, kaddr,
1715 PAGE_SIZE)) {
1716 kunmap(page);
1717 page_cache_release(page);
1718 goto end_coredump;
1719 }
1720 kunmap(page);
1721 }
1722 page_cache_release(page);
1723 }
1724 }
1725 }
1726
1727#ifdef ELF_CORE_WRITE_EXTRA_DATA
1728 ELF_CORE_WRITE_EXTRA_DATA;
1729#endif
1730
Linus Torvalds1da177e2005-04-16 15:20:36 -07001731end_coredump:
1732 set_fs(fs);
1733
1734cleanup:
Jesper Juhl74da6cd2006-01-11 01:51:26 +01001735 while (!list_empty(&thread_list)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001736 struct list_head *tmp = thread_list.next;
1737 list_del(tmp);
1738 kfree(list_entry(tmp, struct elf_thread_status, list));
1739 }
1740
1741 kfree(elf);
1742 kfree(prstatus);
1743 kfree(psinfo);
1744 kfree(notes);
1745 kfree(fpu);
1746#ifdef ELF_CORE_COPY_XFPREGS
1747 kfree(xfpu);
1748#endif
1749 return has_dumped;
1750#undef NUM_NOTES
1751}
1752
1753#endif /* USE_ELF_CORE_DUMP */
1754
1755static int __init init_elf_binfmt(void)
1756{
1757 return register_binfmt(&elf_format);
1758}
1759
1760static void __exit exit_elf_binfmt(void)
1761{
1762 /* Remove the COFF and ELF loaders. */
1763 unregister_binfmt(&elf_format);
1764}
1765
1766core_initcall(init_elf_binfmt);
1767module_exit(exit_elf_binfmt);
1768MODULE_LICENSE("GPL");