Avoid beyond bounds copy while caching ACL
[zen-stable.git] / fs / binfmt_elf.c
blob07d096c49920cf21308480da107a6064a889db47
1 /*
2 * linux/fs/binfmt_elf.c
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".
9 * Copyright 1993, 1994: Eric Youngdale (ericy@cais.com).
12 #include <linux/module.h>
13 #include <linux/kernel.h>
14 #include <linux/fs.h>
15 #include <linux/mm.h>
16 #include <linux/mman.h>
17 #include <linux/errno.h>
18 #include <linux/signal.h>
19 #include <linux/binfmts.h>
20 #include <linux/string.h>
21 #include <linux/file.h>
22 #include <linux/slab.h>
23 #include <linux/personality.h>
24 #include <linux/elfcore.h>
25 #include <linux/init.h>
26 #include <linux/highuid.h>
27 #include <linux/compiler.h>
28 #include <linux/highmem.h>
29 #include <linux/pagemap.h>
30 #include <linux/security.h>
31 #include <linux/random.h>
32 #include <linux/elf.h>
33 #include <linux/utsname.h>
34 #include <linux/coredump.h>
35 #include <asm/uaccess.h>
36 #include <asm/param.h>
37 #include <asm/page.h>
39 static int load_elf_binary(struct linux_binprm *bprm, struct pt_regs *regs);
40 static int load_elf_library(struct file *);
41 static unsigned long elf_map(struct file *, unsigned long, struct elf_phdr *,
42 int, int, unsigned long);
45 * If we don't support core dumping, then supply a NULL so we
46 * don't even try.
48 #ifdef CONFIG_ELF_CORE
49 static int elf_core_dump(struct coredump_params *cprm);
50 #else
51 #define elf_core_dump NULL
52 #endif
54 #if ELF_EXEC_PAGESIZE > PAGE_SIZE
55 #define ELF_MIN_ALIGN ELF_EXEC_PAGESIZE
56 #else
57 #define ELF_MIN_ALIGN PAGE_SIZE
58 #endif
60 #ifndef ELF_CORE_EFLAGS
61 #define ELF_CORE_EFLAGS 0
62 #endif
64 #define ELF_PAGESTART(_v) ((_v) & ~(unsigned long)(ELF_MIN_ALIGN-1))
65 #define ELF_PAGEOFFSET(_v) ((_v) & (ELF_MIN_ALIGN-1))
66 #define ELF_PAGEALIGN(_v) (((_v) + ELF_MIN_ALIGN - 1) & ~(ELF_MIN_ALIGN - 1))
68 static struct linux_binfmt elf_format = {
69 .module = THIS_MODULE,
70 .load_binary = load_elf_binary,
71 .load_shlib = load_elf_library,
72 .core_dump = elf_core_dump,
73 .min_coredump = ELF_EXEC_PAGESIZE,
76 #define BAD_ADDR(x) ((unsigned long)(x) >= TASK_SIZE)
78 static int set_brk(unsigned long start, unsigned long end)
80 start = ELF_PAGEALIGN(start);
81 end = ELF_PAGEALIGN(end);
82 if (end > start) {
83 unsigned long addr;
84 down_write(&current->mm->mmap_sem);
85 addr = do_brk(start, end - start);
86 up_write(&current->mm->mmap_sem);
87 if (BAD_ADDR(addr))
88 return addr;
90 current->mm->start_brk = current->mm->brk = end;
91 return 0;
94 /* We need to explicitly zero any fractional pages
95 after the data section (i.e. bss). This would
96 contain the junk from the file that should not
97 be in memory
99 static int padzero(unsigned long elf_bss)
101 unsigned long nbyte;
103 nbyte = ELF_PAGEOFFSET(elf_bss);
104 if (nbyte) {
105 nbyte = ELF_MIN_ALIGN - nbyte;
106 if (clear_user((void __user *) elf_bss, nbyte))
107 return -EFAULT;
109 return 0;
112 /* Let's use some macros to make this stack manipulation a little clearer */
113 #ifdef CONFIG_STACK_GROWSUP
114 #define STACK_ADD(sp, items) ((elf_addr_t __user *)(sp) + (items))
115 #define STACK_ROUND(sp, items) \
116 ((15 + (unsigned long) ((sp) + (items))) &~ 15UL)
117 #define STACK_ALLOC(sp, len) ({ \
118 elf_addr_t __user *old_sp = (elf_addr_t __user *)sp; sp += len; \
119 old_sp; })
120 #else
121 #define STACK_ADD(sp, items) ((elf_addr_t __user *)(sp) - (items))
122 #define STACK_ROUND(sp, items) \
123 (((unsigned long) (sp - items)) &~ 15UL)
124 #define STACK_ALLOC(sp, len) ({ sp -= len ; sp; })
125 #endif
127 #ifndef ELF_BASE_PLATFORM
129 * AT_BASE_PLATFORM indicates the "real" hardware/microarchitecture.
130 * If the arch defines ELF_BASE_PLATFORM (in asm/elf.h), the value
131 * will be copied to the user stack in the same manner as AT_PLATFORM.
133 #define ELF_BASE_PLATFORM NULL
134 #endif
136 static int
137 create_elf_tables(struct linux_binprm *bprm, struct elfhdr *exec,
138 unsigned long load_addr, unsigned long interp_load_addr)
140 unsigned long p = bprm->p;
141 int argc = bprm->argc;
142 int envc = bprm->envc;
143 elf_addr_t __user *argv;
144 elf_addr_t __user *envp;
145 elf_addr_t __user *sp;
146 elf_addr_t __user *u_platform;
147 elf_addr_t __user *u_base_platform;
148 elf_addr_t __user *u_rand_bytes;
149 const char *k_platform = ELF_PLATFORM;
150 const char *k_base_platform = ELF_BASE_PLATFORM;
151 unsigned char k_rand_bytes[16];
152 int items;
153 elf_addr_t *elf_info;
154 int ei_index = 0;
155 const struct cred *cred = current_cred();
156 struct vm_area_struct *vma;
159 * In some cases (e.g. Hyper-Threading), we want to avoid L1
160 * evictions by the processes running on the same package. One
161 * thing we can do is to shuffle the initial stack for them.
164 p = arch_align_stack(p);
167 * If this architecture has a platform capability string, copy it
168 * to userspace. In some cases (Sparc), this info is impossible
169 * for userspace to get any other way, in others (i386) it is
170 * merely difficult.
172 u_platform = NULL;
173 if (k_platform) {
174 size_t len = strlen(k_platform) + 1;
176 u_platform = (elf_addr_t __user *)STACK_ALLOC(p, len);
177 if (__copy_to_user(u_platform, k_platform, len))
178 return -EFAULT;
182 * If this architecture has a "base" platform capability
183 * string, copy it to userspace.
185 u_base_platform = NULL;
186 if (k_base_platform) {
187 size_t len = strlen(k_base_platform) + 1;
189 u_base_platform = (elf_addr_t __user *)STACK_ALLOC(p, len);
190 if (__copy_to_user(u_base_platform, k_base_platform, len))
191 return -EFAULT;
195 * Generate 16 random bytes for userspace PRNG seeding.
197 get_random_bytes(k_rand_bytes, sizeof(k_rand_bytes));
198 u_rand_bytes = (elf_addr_t __user *)
199 STACK_ALLOC(p, sizeof(k_rand_bytes));
200 if (__copy_to_user(u_rand_bytes, k_rand_bytes, sizeof(k_rand_bytes)))
201 return -EFAULT;
203 /* Create the ELF interpreter info */
204 elf_info = (elf_addr_t *)current->mm->saved_auxv;
205 /* update AT_VECTOR_SIZE_BASE if the number of NEW_AUX_ENT() changes */
206 #define NEW_AUX_ENT(id, val) \
207 do { \
208 elf_info[ei_index++] = id; \
209 elf_info[ei_index++] = val; \
210 } while (0)
212 #ifdef ARCH_DLINFO
214 * ARCH_DLINFO must come first so PPC can do its special alignment of
215 * AUXV.
216 * update AT_VECTOR_SIZE_ARCH if the number of NEW_AUX_ENT() in
217 * ARCH_DLINFO changes
219 ARCH_DLINFO;
220 #endif
221 NEW_AUX_ENT(AT_HWCAP, ELF_HWCAP);
222 NEW_AUX_ENT(AT_PAGESZ, ELF_EXEC_PAGESIZE);
223 NEW_AUX_ENT(AT_CLKTCK, CLOCKS_PER_SEC);
224 NEW_AUX_ENT(AT_PHDR, load_addr + exec->e_phoff);
225 NEW_AUX_ENT(AT_PHENT, sizeof(struct elf_phdr));
226 NEW_AUX_ENT(AT_PHNUM, exec->e_phnum);
227 NEW_AUX_ENT(AT_BASE, interp_load_addr);
228 NEW_AUX_ENT(AT_FLAGS, 0);
229 NEW_AUX_ENT(AT_ENTRY, exec->e_entry);
230 NEW_AUX_ENT(AT_UID, cred->uid);
231 NEW_AUX_ENT(AT_EUID, cred->euid);
232 NEW_AUX_ENT(AT_GID, cred->gid);
233 NEW_AUX_ENT(AT_EGID, cred->egid);
234 NEW_AUX_ENT(AT_SECURE, security_bprm_secureexec(bprm));
235 NEW_AUX_ENT(AT_RANDOM, (elf_addr_t)(unsigned long)u_rand_bytes);
236 NEW_AUX_ENT(AT_EXECFN, bprm->exec);
237 if (k_platform) {
238 NEW_AUX_ENT(AT_PLATFORM,
239 (elf_addr_t)(unsigned long)u_platform);
241 if (k_base_platform) {
242 NEW_AUX_ENT(AT_BASE_PLATFORM,
243 (elf_addr_t)(unsigned long)u_base_platform);
245 if (bprm->interp_flags & BINPRM_FLAGS_EXECFD) {
246 NEW_AUX_ENT(AT_EXECFD, bprm->interp_data);
248 #undef NEW_AUX_ENT
249 /* AT_NULL is zero; clear the rest too */
250 memset(&elf_info[ei_index], 0,
251 sizeof current->mm->saved_auxv - ei_index * sizeof elf_info[0]);
253 /* And advance past the AT_NULL entry. */
254 ei_index += 2;
256 sp = STACK_ADD(p, ei_index);
258 items = (argc + 1) + (envc + 1) + 1;
259 bprm->p = STACK_ROUND(sp, items);
261 /* Point sp at the lowest address on the stack */
262 #ifdef CONFIG_STACK_GROWSUP
263 sp = (elf_addr_t __user *)bprm->p - items - ei_index;
264 bprm->exec = (unsigned long)sp; /* XXX: PARISC HACK */
265 #else
266 sp = (elf_addr_t __user *)bprm->p;
267 #endif
271 * Grow the stack manually; some architectures have a limit on how
272 * far ahead a user-space access may be in order to grow the stack.
274 vma = find_extend_vma(current->mm, bprm->p);
275 if (!vma)
276 return -EFAULT;
278 /* Now, let's put argc (and argv, envp if appropriate) on the stack */
279 if (__put_user(argc, sp++))
280 return -EFAULT;
281 argv = sp;
282 envp = argv + argc + 1;
284 /* Populate argv and envp */
285 p = current->mm->arg_end = current->mm->arg_start;
286 while (argc-- > 0) {
287 size_t len;
288 if (__put_user((elf_addr_t)p, argv++))
289 return -EFAULT;
290 len = strnlen_user((void __user *)p, MAX_ARG_STRLEN);
291 if (!len || len > MAX_ARG_STRLEN)
292 return -EINVAL;
293 p += len;
295 if (__put_user(0, argv))
296 return -EFAULT;
297 current->mm->arg_end = current->mm->env_start = p;
298 while (envc-- > 0) {
299 size_t len;
300 if (__put_user((elf_addr_t)p, envp++))
301 return -EFAULT;
302 len = strnlen_user((void __user *)p, MAX_ARG_STRLEN);
303 if (!len || len > MAX_ARG_STRLEN)
304 return -EINVAL;
305 p += len;
307 if (__put_user(0, envp))
308 return -EFAULT;
309 current->mm->env_end = p;
311 /* Put the elf_info on the stack in the right place. */
312 sp = (elf_addr_t __user *)envp + 1;
313 if (copy_to_user(sp, elf_info, ei_index * sizeof(elf_addr_t)))
314 return -EFAULT;
315 return 0;
318 static unsigned long elf_map(struct file *filep, unsigned long addr,
319 struct elf_phdr *eppnt, int prot, int type,
320 unsigned long total_size)
322 unsigned long map_addr;
323 unsigned long size = eppnt->p_filesz + ELF_PAGEOFFSET(eppnt->p_vaddr);
324 unsigned long off = eppnt->p_offset - ELF_PAGEOFFSET(eppnt->p_vaddr);
325 addr = ELF_PAGESTART(addr);
326 size = ELF_PAGEALIGN(size);
328 /* mmap() will return -EINVAL if given a zero size, but a
329 * segment with zero filesize is perfectly valid */
330 if (!size)
331 return addr;
333 down_write(&current->mm->mmap_sem);
335 * total_size is the size of the ELF (interpreter) image.
336 * The _first_ mmap needs to know the full size, otherwise
337 * randomization might put this image into an overlapping
338 * position with the ELF binary image. (since size < total_size)
339 * So we first map the 'big' image - and unmap the remainder at
340 * the end. (which unmap is needed for ELF images with holes.)
342 if (total_size) {
343 total_size = ELF_PAGEALIGN(total_size);
344 map_addr = do_mmap(filep, addr, total_size, prot, type, off);
345 if (!BAD_ADDR(map_addr))
346 do_munmap(current->mm, map_addr+size, total_size-size);
347 } else
348 map_addr = do_mmap(filep, addr, size, prot, type, off);
350 up_write(&current->mm->mmap_sem);
351 return(map_addr);
354 static unsigned long total_mapping_size(struct elf_phdr *cmds, int nr)
356 int i, first_idx = -1, last_idx = -1;
358 for (i = 0; i < nr; i++) {
359 if (cmds[i].p_type == PT_LOAD) {
360 last_idx = i;
361 if (first_idx == -1)
362 first_idx = i;
365 if (first_idx == -1)
366 return 0;
368 return cmds[last_idx].p_vaddr + cmds[last_idx].p_memsz -
369 ELF_PAGESTART(cmds[first_idx].p_vaddr);
373 /* This is much more generalized than the library routine read function,
374 so we keep this separate. Technically the library read function
375 is only provided so that we can read a.out libraries that have
376 an ELF header */
378 static unsigned long load_elf_interp(struct elfhdr *interp_elf_ex,
379 struct file *interpreter, unsigned long *interp_map_addr,
380 unsigned long no_base)
382 struct elf_phdr *elf_phdata;
383 struct elf_phdr *eppnt;
384 unsigned long load_addr = 0;
385 int load_addr_set = 0;
386 unsigned long last_bss = 0, elf_bss = 0;
387 unsigned long error = ~0UL;
388 unsigned long total_size;
389 int retval, i, size;
391 /* First of all, some simple consistency checks */
392 if (interp_elf_ex->e_type != ET_EXEC &&
393 interp_elf_ex->e_type != ET_DYN)
394 goto out;
395 if (!elf_check_arch(interp_elf_ex))
396 goto out;
397 if (!interpreter->f_op || !interpreter->f_op->mmap)
398 goto out;
401 * If the size of this structure has changed, then punt, since
402 * we will be doing the wrong thing.
404 if (interp_elf_ex->e_phentsize != sizeof(struct elf_phdr))
405 goto out;
406 if (interp_elf_ex->e_phnum < 1 ||
407 interp_elf_ex->e_phnum > 65536U / sizeof(struct elf_phdr))
408 goto out;
410 /* Now read in all of the header information */
411 size = sizeof(struct elf_phdr) * interp_elf_ex->e_phnum;
412 if (size > ELF_MIN_ALIGN)
413 goto out;
414 elf_phdata = kmalloc(size, GFP_KERNEL);
415 if (!elf_phdata)
416 goto out;
418 retval = kernel_read(interpreter, interp_elf_ex->e_phoff,
419 (char *)elf_phdata, size);
420 error = -EIO;
421 if (retval != size) {
422 if (retval < 0)
423 error = retval;
424 goto out_close;
427 total_size = total_mapping_size(elf_phdata, interp_elf_ex->e_phnum);
428 if (!total_size) {
429 error = -EINVAL;
430 goto out_close;
433 eppnt = elf_phdata;
434 for (i = 0; i < interp_elf_ex->e_phnum; i++, eppnt++) {
435 if (eppnt->p_type == PT_LOAD) {
436 int elf_type = MAP_PRIVATE | MAP_DENYWRITE;
437 int elf_prot = 0;
438 unsigned long vaddr = 0;
439 unsigned long k, map_addr;
441 if (eppnt->p_flags & PF_R)
442 elf_prot = PROT_READ;
443 if (eppnt->p_flags & PF_W)
444 elf_prot |= PROT_WRITE;
445 if (eppnt->p_flags & PF_X)
446 elf_prot |= PROT_EXEC;
447 vaddr = eppnt->p_vaddr;
448 if (interp_elf_ex->e_type == ET_EXEC || load_addr_set)
449 elf_type |= MAP_FIXED;
450 else if (no_base && interp_elf_ex->e_type == ET_DYN)
451 load_addr = -vaddr;
453 map_addr = elf_map(interpreter, load_addr + vaddr,
454 eppnt, elf_prot, elf_type, total_size);
455 total_size = 0;
456 if (!*interp_map_addr)
457 *interp_map_addr = map_addr;
458 error = map_addr;
459 if (BAD_ADDR(map_addr))
460 goto out_close;
462 if (!load_addr_set &&
463 interp_elf_ex->e_type == ET_DYN) {
464 load_addr = map_addr - ELF_PAGESTART(vaddr);
465 load_addr_set = 1;
469 * Check to see if the section's size will overflow the
470 * allowed task size. Note that p_filesz must always be
471 * <= p_memsize so it's only necessary to check p_memsz.
473 k = load_addr + eppnt->p_vaddr;
474 if (BAD_ADDR(k) ||
475 eppnt->p_filesz > eppnt->p_memsz ||
476 eppnt->p_memsz > TASK_SIZE ||
477 TASK_SIZE - eppnt->p_memsz < k) {
478 error = -ENOMEM;
479 goto out_close;
483 * Find the end of the file mapping for this phdr, and
484 * keep track of the largest address we see for this.
486 k = load_addr + eppnt->p_vaddr + eppnt->p_filesz;
487 if (k > elf_bss)
488 elf_bss = k;
491 * Do the same thing for the memory mapping - between
492 * elf_bss and last_bss is the bss section.
494 k = load_addr + eppnt->p_memsz + eppnt->p_vaddr;
495 if (k > last_bss)
496 last_bss = k;
500 if (last_bss > elf_bss) {
502 * Now fill out the bss section. First pad the last page up
503 * to the page boundary, and then perform a mmap to make sure
504 * that there are zero-mapped pages up to and including the
505 * last bss page.
507 if (padzero(elf_bss)) {
508 error = -EFAULT;
509 goto out_close;
512 /* What we have mapped so far */
513 elf_bss = ELF_PAGESTART(elf_bss + ELF_MIN_ALIGN - 1);
515 /* Map the last of the bss segment */
516 down_write(&current->mm->mmap_sem);
517 error = do_brk(elf_bss, last_bss - elf_bss);
518 up_write(&current->mm->mmap_sem);
519 if (BAD_ADDR(error))
520 goto out_close;
523 error = load_addr;
525 out_close:
526 kfree(elf_phdata);
527 out:
528 return error;
532 * These are the functions used to load ELF style executables and shared
533 * libraries. There is no binary dependent code anywhere else.
536 #define INTERPRETER_NONE 0
537 #define INTERPRETER_ELF 2
539 #ifndef STACK_RND_MASK
540 #define STACK_RND_MASK (0x7ff >> (PAGE_SHIFT - 12)) /* 8MB of VA */
541 #endif
543 static unsigned long randomize_stack_top(unsigned long stack_top)
545 unsigned int random_variable = 0;
547 if ((current->flags & PF_RANDOMIZE) &&
548 !(current->personality & ADDR_NO_RANDOMIZE)) {
549 random_variable = get_random_int() & STACK_RND_MASK;
550 random_variable <<= PAGE_SHIFT;
552 #ifdef CONFIG_STACK_GROWSUP
553 return PAGE_ALIGN(stack_top) + random_variable;
554 #else
555 return PAGE_ALIGN(stack_top) - random_variable;
556 #endif
559 static int load_elf_binary(struct linux_binprm *bprm, struct pt_regs *regs)
561 struct file *interpreter = NULL; /* to shut gcc up */
562 unsigned long load_addr = 0, load_bias = 0;
563 int load_addr_set = 0;
564 char * elf_interpreter = NULL;
565 unsigned long error;
566 struct elf_phdr *elf_ppnt, *elf_phdata;
567 unsigned long elf_bss, elf_brk;
568 int retval, i;
569 unsigned int size;
570 unsigned long elf_entry;
571 unsigned long interp_load_addr = 0;
572 unsigned long start_code, end_code, start_data, end_data;
573 unsigned long reloc_func_desc __maybe_unused = 0;
574 int executable_stack = EXSTACK_DEFAULT;
575 unsigned long def_flags = 0;
576 struct {
577 struct elfhdr elf_ex;
578 struct elfhdr interp_elf_ex;
579 } *loc;
581 loc = kmalloc(sizeof(*loc), GFP_KERNEL);
582 if (!loc) {
583 retval = -ENOMEM;
584 goto out_ret;
587 /* Get the exec-header */
588 loc->elf_ex = *((struct elfhdr *)bprm->buf);
590 retval = -ENOEXEC;
591 /* First of all, some simple consistency checks */
592 if (memcmp(loc->elf_ex.e_ident, ELFMAG, SELFMAG) != 0)
593 goto out;
595 if (loc->elf_ex.e_type != ET_EXEC && loc->elf_ex.e_type != ET_DYN)
596 goto out;
597 if (!elf_check_arch(&loc->elf_ex))
598 goto out;
599 if (!bprm->file->f_op || !bprm->file->f_op->mmap)
600 goto out;
602 /* Now read in all of the header information */
603 if (loc->elf_ex.e_phentsize != sizeof(struct elf_phdr))
604 goto out;
605 if (loc->elf_ex.e_phnum < 1 ||
606 loc->elf_ex.e_phnum > 65536U / sizeof(struct elf_phdr))
607 goto out;
608 size = loc->elf_ex.e_phnum * sizeof(struct elf_phdr);
609 retval = -ENOMEM;
610 elf_phdata = kmalloc(size, GFP_KERNEL);
611 if (!elf_phdata)
612 goto out;
614 retval = kernel_read(bprm->file, loc->elf_ex.e_phoff,
615 (char *)elf_phdata, size);
616 if (retval != size) {
617 if (retval >= 0)
618 retval = -EIO;
619 goto out_free_ph;
622 elf_ppnt = elf_phdata;
623 elf_bss = 0;
624 elf_brk = 0;
626 start_code = ~0UL;
627 end_code = 0;
628 start_data = 0;
629 end_data = 0;
631 for (i = 0; i < loc->elf_ex.e_phnum; i++) {
632 if (elf_ppnt->p_type == PT_INTERP) {
633 /* This is the program interpreter used for
634 * shared libraries - for now assume that this
635 * is an a.out format binary
637 retval = -ENOEXEC;
638 if (elf_ppnt->p_filesz > PATH_MAX ||
639 elf_ppnt->p_filesz < 2)
640 goto out_free_ph;
642 retval = -ENOMEM;
643 elf_interpreter = kmalloc(elf_ppnt->p_filesz,
644 GFP_KERNEL);
645 if (!elf_interpreter)
646 goto out_free_ph;
648 retval = kernel_read(bprm->file, elf_ppnt->p_offset,
649 elf_interpreter,
650 elf_ppnt->p_filesz);
651 if (retval != elf_ppnt->p_filesz) {
652 if (retval >= 0)
653 retval = -EIO;
654 goto out_free_interp;
656 /* make sure path is NULL terminated */
657 retval = -ENOEXEC;
658 if (elf_interpreter[elf_ppnt->p_filesz - 1] != '\0')
659 goto out_free_interp;
661 interpreter = open_exec(elf_interpreter);
662 retval = PTR_ERR(interpreter);
663 if (IS_ERR(interpreter))
664 goto out_free_interp;
667 * If the binary is not readable then enforce
668 * mm->dumpable = 0 regardless of the interpreter's
669 * permissions.
671 would_dump(bprm, interpreter);
673 retval = kernel_read(interpreter, 0, bprm->buf,
674 BINPRM_BUF_SIZE);
675 if (retval != BINPRM_BUF_SIZE) {
676 if (retval >= 0)
677 retval = -EIO;
678 goto out_free_dentry;
681 /* Get the exec headers */
682 loc->interp_elf_ex = *((struct elfhdr *)bprm->buf);
683 break;
685 elf_ppnt++;
688 elf_ppnt = elf_phdata;
689 for (i = 0; i < loc->elf_ex.e_phnum; i++, elf_ppnt++)
690 if (elf_ppnt->p_type == PT_GNU_STACK) {
691 if (elf_ppnt->p_flags & PF_X)
692 executable_stack = EXSTACK_ENABLE_X;
693 else
694 executable_stack = EXSTACK_DISABLE_X;
695 break;
698 /* Some simple consistency checks for the interpreter */
699 if (elf_interpreter) {
700 retval = -ELIBBAD;
701 /* Not an ELF interpreter */
702 if (memcmp(loc->interp_elf_ex.e_ident, ELFMAG, SELFMAG) != 0)
703 goto out_free_dentry;
704 /* Verify the interpreter has a valid arch */
705 if (!elf_check_arch(&loc->interp_elf_ex))
706 goto out_free_dentry;
709 /* Flush all traces of the currently running executable */
710 retval = flush_old_exec(bprm);
711 if (retval)
712 goto out_free_dentry;
714 /* OK, This is the point of no return */
715 current->flags &= ~PF_FORKNOEXEC;
716 current->mm->def_flags = def_flags;
718 /* Do this immediately, since STACK_TOP as used in setup_arg_pages
719 may depend on the personality. */
720 SET_PERSONALITY(loc->elf_ex);
721 if (elf_read_implies_exec(loc->elf_ex, executable_stack))
722 current->personality |= READ_IMPLIES_EXEC;
724 if (!(current->personality & ADDR_NO_RANDOMIZE) && randomize_va_space)
725 current->flags |= PF_RANDOMIZE;
727 setup_new_exec(bprm);
729 /* Do this so that we can load the interpreter, if need be. We will
730 change some of these later */
731 current->mm->free_area_cache = current->mm->mmap_base;
732 current->mm->cached_hole_size = 0;
733 retval = setup_arg_pages(bprm, randomize_stack_top(STACK_TOP),
734 executable_stack);
735 if (retval < 0) {
736 send_sig(SIGKILL, current, 0);
737 goto out_free_dentry;
740 current->mm->start_stack = bprm->p;
742 /* Now we do a little grungy work by mmapping the ELF image into
743 the correct location in memory. */
744 for(i = 0, elf_ppnt = elf_phdata;
745 i < loc->elf_ex.e_phnum; i++, elf_ppnt++) {
746 int elf_prot = 0, elf_flags;
747 unsigned long k, vaddr;
749 if (elf_ppnt->p_type != PT_LOAD)
750 continue;
752 if (unlikely (elf_brk > elf_bss)) {
753 unsigned long nbyte;
755 /* There was a PT_LOAD segment with p_memsz > p_filesz
756 before this one. Map anonymous pages, if needed,
757 and clear the area. */
758 retval = set_brk(elf_bss + load_bias,
759 elf_brk + load_bias);
760 if (retval) {
761 send_sig(SIGKILL, current, 0);
762 goto out_free_dentry;
764 nbyte = ELF_PAGEOFFSET(elf_bss);
765 if (nbyte) {
766 nbyte = ELF_MIN_ALIGN - nbyte;
767 if (nbyte > elf_brk - elf_bss)
768 nbyte = elf_brk - elf_bss;
769 if (clear_user((void __user *)elf_bss +
770 load_bias, nbyte)) {
772 * This bss-zeroing can fail if the ELF
773 * file specifies odd protections. So
774 * we don't check the return value
780 if (elf_ppnt->p_flags & PF_R)
781 elf_prot |= PROT_READ;
782 if (elf_ppnt->p_flags & PF_W)
783 elf_prot |= PROT_WRITE;
784 if (elf_ppnt->p_flags & PF_X)
785 elf_prot |= PROT_EXEC;
787 elf_flags = MAP_PRIVATE | MAP_DENYWRITE | MAP_EXECUTABLE;
789 vaddr = elf_ppnt->p_vaddr;
790 if (loc->elf_ex.e_type == ET_EXEC || load_addr_set) {
791 elf_flags |= MAP_FIXED;
792 } else if (loc->elf_ex.e_type == ET_DYN) {
793 /* Try and get dynamic programs out of the way of the
794 * default mmap base, as well as whatever program they
795 * might try to exec. This is because the brk will
796 * follow the loader, and is not movable. */
797 #ifdef CONFIG_ARCH_BINFMT_ELF_RANDOMIZE_PIE
798 /* Memory randomization might have been switched off
799 * in runtime via sysctl.
800 * If that is the case, retain the original non-zero
801 * load_bias value in order to establish proper
802 * non-randomized mappings.
804 if (current->flags & PF_RANDOMIZE)
805 load_bias = 0;
806 else
807 load_bias = ELF_PAGESTART(ELF_ET_DYN_BASE - vaddr);
808 #else
809 load_bias = ELF_PAGESTART(ELF_ET_DYN_BASE - vaddr);
810 #endif
813 error = elf_map(bprm->file, load_bias + vaddr, elf_ppnt,
814 elf_prot, elf_flags, 0);
815 if (BAD_ADDR(error)) {
816 send_sig(SIGKILL, current, 0);
817 retval = IS_ERR((void *)error) ?
818 PTR_ERR((void*)error) : -EINVAL;
819 goto out_free_dentry;
822 if (!load_addr_set) {
823 load_addr_set = 1;
824 load_addr = (elf_ppnt->p_vaddr - elf_ppnt->p_offset);
825 if (loc->elf_ex.e_type == ET_DYN) {
826 load_bias += error -
827 ELF_PAGESTART(load_bias + vaddr);
828 load_addr += load_bias;
829 reloc_func_desc = load_bias;
832 k = elf_ppnt->p_vaddr;
833 if (k < start_code)
834 start_code = k;
835 if (start_data < k)
836 start_data = k;
839 * Check to see if the section's size will overflow the
840 * allowed task size. Note that p_filesz must always be
841 * <= p_memsz so it is only necessary to check p_memsz.
843 if (BAD_ADDR(k) || elf_ppnt->p_filesz > elf_ppnt->p_memsz ||
844 elf_ppnt->p_memsz > TASK_SIZE ||
845 TASK_SIZE - elf_ppnt->p_memsz < k) {
846 /* set_brk can never work. Avoid overflows. */
847 send_sig(SIGKILL, current, 0);
848 retval = -EINVAL;
849 goto out_free_dentry;
852 k = elf_ppnt->p_vaddr + elf_ppnt->p_filesz;
854 if (k > elf_bss)
855 elf_bss = k;
856 if ((elf_ppnt->p_flags & PF_X) && end_code < k)
857 end_code = k;
858 if (end_data < k)
859 end_data = k;
860 k = elf_ppnt->p_vaddr + elf_ppnt->p_memsz;
861 if (k > elf_brk)
862 elf_brk = k;
865 loc->elf_ex.e_entry += load_bias;
866 elf_bss += load_bias;
867 elf_brk += load_bias;
868 start_code += load_bias;
869 end_code += load_bias;
870 start_data += load_bias;
871 end_data += load_bias;
873 /* Calling set_brk effectively mmaps the pages that we need
874 * for the bss and break sections. We must do this before
875 * mapping in the interpreter, to make sure it doesn't wind
876 * up getting placed where the bss needs to go.
878 retval = set_brk(elf_bss, elf_brk);
879 if (retval) {
880 send_sig(SIGKILL, current, 0);
881 goto out_free_dentry;
883 if (likely(elf_bss != elf_brk) && unlikely(padzero(elf_bss))) {
884 send_sig(SIGSEGV, current, 0);
885 retval = -EFAULT; /* Nobody gets to see this, but.. */
886 goto out_free_dentry;
889 if (elf_interpreter) {
890 unsigned long uninitialized_var(interp_map_addr);
892 elf_entry = load_elf_interp(&loc->interp_elf_ex,
893 interpreter,
894 &interp_map_addr,
895 load_bias);
896 if (!IS_ERR((void *)elf_entry)) {
898 * load_elf_interp() returns relocation
899 * adjustment
901 interp_load_addr = elf_entry;
902 elf_entry += loc->interp_elf_ex.e_entry;
904 if (BAD_ADDR(elf_entry)) {
905 force_sig(SIGSEGV, current);
906 retval = IS_ERR((void *)elf_entry) ?
907 (int)elf_entry : -EINVAL;
908 goto out_free_dentry;
910 reloc_func_desc = interp_load_addr;
912 allow_write_access(interpreter);
913 fput(interpreter);
914 kfree(elf_interpreter);
915 } else {
916 elf_entry = loc->elf_ex.e_entry;
917 if (BAD_ADDR(elf_entry)) {
918 force_sig(SIGSEGV, current);
919 retval = -EINVAL;
920 goto out_free_dentry;
924 kfree(elf_phdata);
926 set_binfmt(&elf_format);
928 #ifdef ARCH_HAS_SETUP_ADDITIONAL_PAGES
929 retval = arch_setup_additional_pages(bprm, !!elf_interpreter);
930 if (retval < 0) {
931 send_sig(SIGKILL, current, 0);
932 goto out;
934 #endif /* ARCH_HAS_SETUP_ADDITIONAL_PAGES */
936 install_exec_creds(bprm);
937 current->flags &= ~PF_FORKNOEXEC;
938 retval = create_elf_tables(bprm, &loc->elf_ex,
939 load_addr, interp_load_addr);
940 if (retval < 0) {
941 send_sig(SIGKILL, current, 0);
942 goto out;
944 /* N.B. passed_fileno might not be initialized? */
945 current->mm->end_code = end_code;
946 current->mm->start_code = start_code;
947 current->mm->start_data = start_data;
948 current->mm->end_data = end_data;
949 current->mm->start_stack = bprm->p;
951 #ifdef arch_randomize_brk
952 if ((current->flags & PF_RANDOMIZE) && (randomize_va_space > 1)) {
953 current->mm->brk = current->mm->start_brk =
954 arch_randomize_brk(current->mm);
955 #ifdef CONFIG_COMPAT_BRK
956 current->brk_randomized = 1;
957 #endif
959 #endif
961 if (current->personality & MMAP_PAGE_ZERO) {
962 /* Why this, you ask??? Well SVr4 maps page 0 as read-only,
963 and some applications "depend" upon this behavior.
964 Since we do not have the power to recompile these, we
965 emulate the SVr4 behavior. Sigh. */
966 down_write(&current->mm->mmap_sem);
967 error = do_mmap(NULL, 0, PAGE_SIZE, PROT_READ | PROT_EXEC,
968 MAP_FIXED | MAP_PRIVATE, 0);
969 up_write(&current->mm->mmap_sem);
972 #ifdef ELF_PLAT_INIT
974 * The ABI may specify that certain registers be set up in special
975 * ways (on i386 %edx is the address of a DT_FINI function, for
976 * example. In addition, it may also specify (eg, PowerPC64 ELF)
977 * that the e_entry field is the address of the function descriptor
978 * for the startup routine, rather than the address of the startup
979 * routine itself. This macro performs whatever initialization to
980 * the regs structure is required as well as any relocations to the
981 * function descriptor entries when executing dynamically links apps.
983 ELF_PLAT_INIT(regs, reloc_func_desc);
984 #endif
986 start_thread(regs, elf_entry, bprm->p);
987 retval = 0;
988 out:
989 kfree(loc);
990 out_ret:
991 return retval;
993 /* error cleanup */
994 out_free_dentry:
995 allow_write_access(interpreter);
996 if (interpreter)
997 fput(interpreter);
998 out_free_interp:
999 kfree(elf_interpreter);
1000 out_free_ph:
1001 kfree(elf_phdata);
1002 goto out;
1005 /* This is really simpleminded and specialized - we are loading an
1006 a.out library that is given an ELF header. */
1007 static int load_elf_library(struct file *file)
1009 struct elf_phdr *elf_phdata;
1010 struct elf_phdr *eppnt;
1011 unsigned long elf_bss, bss, len;
1012 int retval, error, i, j;
1013 struct elfhdr elf_ex;
1015 error = -ENOEXEC;
1016 retval = kernel_read(file, 0, (char *)&elf_ex, sizeof(elf_ex));
1017 if (retval != sizeof(elf_ex))
1018 goto out;
1020 if (memcmp(elf_ex.e_ident, ELFMAG, SELFMAG) != 0)
1021 goto out;
1023 /* First of all, some simple consistency checks */
1024 if (elf_ex.e_type != ET_EXEC || elf_ex.e_phnum > 2 ||
1025 !elf_check_arch(&elf_ex) || !file->f_op || !file->f_op->mmap)
1026 goto out;
1028 /* Now read in all of the header information */
1030 j = sizeof(struct elf_phdr) * elf_ex.e_phnum;
1031 /* j < ELF_MIN_ALIGN because elf_ex.e_phnum <= 2 */
1033 error = -ENOMEM;
1034 elf_phdata = kmalloc(j, GFP_KERNEL);
1035 if (!elf_phdata)
1036 goto out;
1038 eppnt = elf_phdata;
1039 error = -ENOEXEC;
1040 retval = kernel_read(file, elf_ex.e_phoff, (char *)eppnt, j);
1041 if (retval != j)
1042 goto out_free_ph;
1044 for (j = 0, i = 0; i<elf_ex.e_phnum; i++)
1045 if ((eppnt + i)->p_type == PT_LOAD)
1046 j++;
1047 if (j != 1)
1048 goto out_free_ph;
1050 while (eppnt->p_type != PT_LOAD)
1051 eppnt++;
1053 /* Now use mmap to map the library into memory. */
1054 down_write(&current->mm->mmap_sem);
1055 error = do_mmap(file,
1056 ELF_PAGESTART(eppnt->p_vaddr),
1057 (eppnt->p_filesz +
1058 ELF_PAGEOFFSET(eppnt->p_vaddr)),
1059 PROT_READ | PROT_WRITE | PROT_EXEC,
1060 MAP_FIXED | MAP_PRIVATE | MAP_DENYWRITE,
1061 (eppnt->p_offset -
1062 ELF_PAGEOFFSET(eppnt->p_vaddr)));
1063 up_write(&current->mm->mmap_sem);
1064 if (error != ELF_PAGESTART(eppnt->p_vaddr))
1065 goto out_free_ph;
1067 elf_bss = eppnt->p_vaddr + eppnt->p_filesz;
1068 if (padzero(elf_bss)) {
1069 error = -EFAULT;
1070 goto out_free_ph;
1073 len = ELF_PAGESTART(eppnt->p_filesz + eppnt->p_vaddr +
1074 ELF_MIN_ALIGN - 1);
1075 bss = eppnt->p_memsz + eppnt->p_vaddr;
1076 if (bss > len) {
1077 down_write(&current->mm->mmap_sem);
1078 do_brk(len, bss - len);
1079 up_write(&current->mm->mmap_sem);
1081 error = 0;
1083 out_free_ph:
1084 kfree(elf_phdata);
1085 out:
1086 return error;
1089 #ifdef CONFIG_ELF_CORE
1091 * ELF core dumper
1093 * Modelled on fs/exec.c:aout_core_dump()
1094 * Jeremy Fitzhardinge <jeremy@sw.oz.au>
1098 * Decide what to dump of a segment, part, all or none.
1100 static unsigned long vma_dump_size(struct vm_area_struct *vma,
1101 unsigned long mm_flags)
1103 #define FILTER(type) (mm_flags & (1UL << MMF_DUMP_##type))
1105 /* The vma can be set up to tell us the answer directly. */
1106 if (vma->vm_flags & VM_ALWAYSDUMP)
1107 goto whole;
1109 /* Hugetlb memory check */
1110 if (vma->vm_flags & VM_HUGETLB) {
1111 if ((vma->vm_flags & VM_SHARED) && FILTER(HUGETLB_SHARED))
1112 goto whole;
1113 if (!(vma->vm_flags & VM_SHARED) && FILTER(HUGETLB_PRIVATE))
1114 goto whole;
1117 /* Do not dump I/O mapped devices or special mappings */
1118 if (vma->vm_flags & (VM_IO | VM_RESERVED))
1119 return 0;
1121 /* By default, dump shared memory if mapped from an anonymous file. */
1122 if (vma->vm_flags & VM_SHARED) {
1123 if (vma->vm_file->f_path.dentry->d_inode->i_nlink == 0 ?
1124 FILTER(ANON_SHARED) : FILTER(MAPPED_SHARED))
1125 goto whole;
1126 return 0;
1129 /* Dump segments that have been written to. */
1130 if (vma->anon_vma && FILTER(ANON_PRIVATE))
1131 goto whole;
1132 if (vma->vm_file == NULL)
1133 return 0;
1135 if (FILTER(MAPPED_PRIVATE))
1136 goto whole;
1139 * If this looks like the beginning of a DSO or executable mapping,
1140 * check for an ELF header. If we find one, dump the first page to
1141 * aid in determining what was mapped here.
1143 if (FILTER(ELF_HEADERS) &&
1144 vma->vm_pgoff == 0 && (vma->vm_flags & VM_READ)) {
1145 u32 __user *header = (u32 __user *) vma->vm_start;
1146 u32 word;
1147 mm_segment_t fs = get_fs();
1149 * Doing it this way gets the constant folded by GCC.
1151 union {
1152 u32 cmp;
1153 char elfmag[SELFMAG];
1154 } magic;
1155 BUILD_BUG_ON(SELFMAG != sizeof word);
1156 magic.elfmag[EI_MAG0] = ELFMAG0;
1157 magic.elfmag[EI_MAG1] = ELFMAG1;
1158 magic.elfmag[EI_MAG2] = ELFMAG2;
1159 magic.elfmag[EI_MAG3] = ELFMAG3;
1161 * Switch to the user "segment" for get_user(),
1162 * then put back what elf_core_dump() had in place.
1164 set_fs(USER_DS);
1165 if (unlikely(get_user(word, header)))
1166 word = 0;
1167 set_fs(fs);
1168 if (word == magic.cmp)
1169 return PAGE_SIZE;
1172 #undef FILTER
1174 return 0;
1176 whole:
1177 return vma->vm_end - vma->vm_start;
1180 /* An ELF note in memory */
1181 struct memelfnote
1183 const char *name;
1184 int type;
1185 unsigned int datasz;
1186 void *data;
1189 static int notesize(struct memelfnote *en)
1191 int sz;
1193 sz = sizeof(struct elf_note);
1194 sz += roundup(strlen(en->name) + 1, 4);
1195 sz += roundup(en->datasz, 4);
1197 return sz;
1200 #define DUMP_WRITE(addr, nr, foffset) \
1201 do { if (!dump_write(file, (addr), (nr))) return 0; *foffset += (nr); } while(0)
1203 static int alignfile(struct file *file, loff_t *foffset)
1205 static const char buf[4] = { 0, };
1206 DUMP_WRITE(buf, roundup(*foffset, 4) - *foffset, foffset);
1207 return 1;
1210 static int writenote(struct memelfnote *men, struct file *file,
1211 loff_t *foffset)
1213 struct elf_note en;
1214 en.n_namesz = strlen(men->name) + 1;
1215 en.n_descsz = men->datasz;
1216 en.n_type = men->type;
1218 DUMP_WRITE(&en, sizeof(en), foffset);
1219 DUMP_WRITE(men->name, en.n_namesz, foffset);
1220 if (!alignfile(file, foffset))
1221 return 0;
1222 DUMP_WRITE(men->data, men->datasz, foffset);
1223 if (!alignfile(file, foffset))
1224 return 0;
1226 return 1;
1228 #undef DUMP_WRITE
1230 static void fill_elf_header(struct elfhdr *elf, int segs,
1231 u16 machine, u32 flags, u8 osabi)
1233 memset(elf, 0, sizeof(*elf));
1235 memcpy(elf->e_ident, ELFMAG, SELFMAG);
1236 elf->e_ident[EI_CLASS] = ELF_CLASS;
1237 elf->e_ident[EI_DATA] = ELF_DATA;
1238 elf->e_ident[EI_VERSION] = EV_CURRENT;
1239 elf->e_ident[EI_OSABI] = ELF_OSABI;
1241 elf->e_type = ET_CORE;
1242 elf->e_machine = machine;
1243 elf->e_version = EV_CURRENT;
1244 elf->e_phoff = sizeof(struct elfhdr);
1245 elf->e_flags = flags;
1246 elf->e_ehsize = sizeof(struct elfhdr);
1247 elf->e_phentsize = sizeof(struct elf_phdr);
1248 elf->e_phnum = segs;
1250 return;
1253 static void fill_elf_note_phdr(struct elf_phdr *phdr, int sz, loff_t offset)
1255 phdr->p_type = PT_NOTE;
1256 phdr->p_offset = offset;
1257 phdr->p_vaddr = 0;
1258 phdr->p_paddr = 0;
1259 phdr->p_filesz = sz;
1260 phdr->p_memsz = 0;
1261 phdr->p_flags = 0;
1262 phdr->p_align = 0;
1263 return;
1266 static void fill_note(struct memelfnote *note, const char *name, int type,
1267 unsigned int sz, void *data)
1269 note->name = name;
1270 note->type = type;
1271 note->datasz = sz;
1272 note->data = data;
1273 return;
1277 * fill up all the fields in prstatus from the given task struct, except
1278 * registers which need to be filled up separately.
1280 static void fill_prstatus(struct elf_prstatus *prstatus,
1281 struct task_struct *p, long signr)
1283 prstatus->pr_info.si_signo = prstatus->pr_cursig = signr;
1284 prstatus->pr_sigpend = p->pending.signal.sig[0];
1285 prstatus->pr_sighold = p->blocked.sig[0];
1286 rcu_read_lock();
1287 prstatus->pr_ppid = task_pid_vnr(rcu_dereference(p->real_parent));
1288 rcu_read_unlock();
1289 prstatus->pr_pid = task_pid_vnr(p);
1290 prstatus->pr_pgrp = task_pgrp_vnr(p);
1291 prstatus->pr_sid = task_session_vnr(p);
1292 if (thread_group_leader(p)) {
1293 struct task_cputime cputime;
1296 * This is the record for the group leader. It shows the
1297 * group-wide total, not its individual thread total.
1299 thread_group_cputime(p, &cputime);
1300 cputime_to_timeval(cputime.utime, &prstatus->pr_utime);
1301 cputime_to_timeval(cputime.stime, &prstatus->pr_stime);
1302 } else {
1303 cputime_to_timeval(p->utime, &prstatus->pr_utime);
1304 cputime_to_timeval(p->stime, &prstatus->pr_stime);
1306 cputime_to_timeval(p->signal->cutime, &prstatus->pr_cutime);
1307 cputime_to_timeval(p->signal->cstime, &prstatus->pr_cstime);
1310 static int fill_psinfo(struct elf_prpsinfo *psinfo, struct task_struct *p,
1311 struct mm_struct *mm)
1313 const struct cred *cred;
1314 unsigned int i, len;
1316 /* first copy the parameters from user space */
1317 memset(psinfo, 0, sizeof(struct elf_prpsinfo));
1319 len = mm->arg_end - mm->arg_start;
1320 if (len >= ELF_PRARGSZ)
1321 len = ELF_PRARGSZ-1;
1322 if (copy_from_user(&psinfo->pr_psargs,
1323 (const char __user *)mm->arg_start, len))
1324 return -EFAULT;
1325 for(i = 0; i < len; i++)
1326 if (psinfo->pr_psargs[i] == 0)
1327 psinfo->pr_psargs[i] = ' ';
1328 psinfo->pr_psargs[len] = 0;
1330 rcu_read_lock();
1331 psinfo->pr_ppid = task_pid_vnr(rcu_dereference(p->real_parent));
1332 rcu_read_unlock();
1333 psinfo->pr_pid = task_pid_vnr(p);
1334 psinfo->pr_pgrp = task_pgrp_vnr(p);
1335 psinfo->pr_sid = task_session_vnr(p);
1337 i = p->state ? ffz(~p->state) + 1 : 0;
1338 psinfo->pr_state = i;
1339 psinfo->pr_sname = (i > 5) ? '.' : "RSDTZW"[i];
1340 psinfo->pr_zomb = psinfo->pr_sname == 'Z';
1341 psinfo->pr_nice = task_nice(p);
1342 psinfo->pr_flag = p->flags;
1343 rcu_read_lock();
1344 cred = __task_cred(p);
1345 SET_UID(psinfo->pr_uid, cred->uid);
1346 SET_GID(psinfo->pr_gid, cred->gid);
1347 rcu_read_unlock();
1348 strncpy(psinfo->pr_fname, p->comm, sizeof(psinfo->pr_fname));
1350 return 0;
1353 static void fill_auxv_note(struct memelfnote *note, struct mm_struct *mm)
1355 elf_addr_t *auxv = (elf_addr_t *) mm->saved_auxv;
1356 int i = 0;
1358 i += 2;
1359 while (auxv[i - 2] != AT_NULL);
1360 fill_note(note, "CORE", NT_AUXV, i * sizeof(elf_addr_t), auxv);
1363 #ifdef CORE_DUMP_USE_REGSET
1364 #include <linux/regset.h>
1366 struct elf_thread_core_info {
1367 struct elf_thread_core_info *next;
1368 struct task_struct *task;
1369 struct elf_prstatus prstatus;
1370 struct memelfnote notes[0];
1373 struct elf_note_info {
1374 struct elf_thread_core_info *thread;
1375 struct memelfnote psinfo;
1376 struct memelfnote auxv;
1377 size_t size;
1378 int thread_notes;
1382 * When a regset has a writeback hook, we call it on each thread before
1383 * dumping user memory. On register window machines, this makes sure the
1384 * user memory backing the register data is up to date before we read it.
1386 static void do_thread_regset_writeback(struct task_struct *task,
1387 const struct user_regset *regset)
1389 if (regset->writeback)
1390 regset->writeback(task, regset, 1);
1393 static int fill_thread_core_info(struct elf_thread_core_info *t,
1394 const struct user_regset_view *view,
1395 long signr, size_t *total)
1397 unsigned int i;
1400 * NT_PRSTATUS is the one special case, because the regset data
1401 * goes into the pr_reg field inside the note contents, rather
1402 * than being the whole note contents. We fill the reset in here.
1403 * We assume that regset 0 is NT_PRSTATUS.
1405 fill_prstatus(&t->prstatus, t->task, signr);
1406 (void) view->regsets[0].get(t->task, &view->regsets[0],
1407 0, sizeof(t->prstatus.pr_reg),
1408 &t->prstatus.pr_reg, NULL);
1410 fill_note(&t->notes[0], "CORE", NT_PRSTATUS,
1411 sizeof(t->prstatus), &t->prstatus);
1412 *total += notesize(&t->notes[0]);
1414 do_thread_regset_writeback(t->task, &view->regsets[0]);
1417 * Each other regset might generate a note too. For each regset
1418 * that has no core_note_type or is inactive, we leave t->notes[i]
1419 * all zero and we'll know to skip writing it later.
1421 for (i = 1; i < view->n; ++i) {
1422 const struct user_regset *regset = &view->regsets[i];
1423 do_thread_regset_writeback(t->task, regset);
1424 if (regset->core_note_type && regset->get &&
1425 (!regset->active || regset->active(t->task, regset))) {
1426 int ret;
1427 size_t size = regset->n * regset->size;
1428 void *data = kmalloc(size, GFP_KERNEL);
1429 if (unlikely(!data))
1430 return 0;
1431 ret = regset->get(t->task, regset,
1432 0, size, data, NULL);
1433 if (unlikely(ret))
1434 kfree(data);
1435 else {
1436 if (regset->core_note_type != NT_PRFPREG)
1437 fill_note(&t->notes[i], "LINUX",
1438 regset->core_note_type,
1439 size, data);
1440 else {
1441 t->prstatus.pr_fpvalid = 1;
1442 fill_note(&t->notes[i], "CORE",
1443 NT_PRFPREG, size, data);
1445 *total += notesize(&t->notes[i]);
1450 return 1;
1453 static int fill_note_info(struct elfhdr *elf, int phdrs,
1454 struct elf_note_info *info,
1455 long signr, struct pt_regs *regs)
1457 struct task_struct *dump_task = current;
1458 const struct user_regset_view *view = task_user_regset_view(dump_task);
1459 struct elf_thread_core_info *t;
1460 struct elf_prpsinfo *psinfo;
1461 struct core_thread *ct;
1462 unsigned int i;
1464 info->size = 0;
1465 info->thread = NULL;
1467 psinfo = kmalloc(sizeof(*psinfo), GFP_KERNEL);
1468 if (psinfo == NULL)
1469 return 0;
1471 fill_note(&info->psinfo, "CORE", NT_PRPSINFO, sizeof(*psinfo), psinfo);
1474 * Figure out how many notes we're going to need for each thread.
1476 info->thread_notes = 0;
1477 for (i = 0; i < view->n; ++i)
1478 if (view->regsets[i].core_note_type != 0)
1479 ++info->thread_notes;
1482 * Sanity check. We rely on regset 0 being in NT_PRSTATUS,
1483 * since it is our one special case.
1485 if (unlikely(info->thread_notes == 0) ||
1486 unlikely(view->regsets[0].core_note_type != NT_PRSTATUS)) {
1487 WARN_ON(1);
1488 return 0;
1492 * Initialize the ELF file header.
1494 fill_elf_header(elf, phdrs,
1495 view->e_machine, view->e_flags, view->ei_osabi);
1498 * Allocate a structure for each thread.
1500 for (ct = &dump_task->mm->core_state->dumper; ct; ct = ct->next) {
1501 t = kzalloc(offsetof(struct elf_thread_core_info,
1502 notes[info->thread_notes]),
1503 GFP_KERNEL);
1504 if (unlikely(!t))
1505 return 0;
1507 t->task = ct->task;
1508 if (ct->task == dump_task || !info->thread) {
1509 t->next = info->thread;
1510 info->thread = t;
1511 } else {
1513 * Make sure to keep the original task at
1514 * the head of the list.
1516 t->next = info->thread->next;
1517 info->thread->next = t;
1522 * Now fill in each thread's information.
1524 for (t = info->thread; t != NULL; t = t->next)
1525 if (!fill_thread_core_info(t, view, signr, &info->size))
1526 return 0;
1529 * Fill in the two process-wide notes.
1531 fill_psinfo(psinfo, dump_task->group_leader, dump_task->mm);
1532 info->size += notesize(&info->psinfo);
1534 fill_auxv_note(&info->auxv, current->mm);
1535 info->size += notesize(&info->auxv);
1537 return 1;
1540 static size_t get_note_info_size(struct elf_note_info *info)
1542 return info->size;
1546 * Write all the notes for each thread. When writing the first thread, the
1547 * process-wide notes are interleaved after the first thread-specific note.
1549 static int write_note_info(struct elf_note_info *info,
1550 struct file *file, loff_t *foffset)
1552 bool first = 1;
1553 struct elf_thread_core_info *t = info->thread;
1555 do {
1556 int i;
1558 if (!writenote(&t->notes[0], file, foffset))
1559 return 0;
1561 if (first && !writenote(&info->psinfo, file, foffset))
1562 return 0;
1563 if (first && !writenote(&info->auxv, file, foffset))
1564 return 0;
1566 for (i = 1; i < info->thread_notes; ++i)
1567 if (t->notes[i].data &&
1568 !writenote(&t->notes[i], file, foffset))
1569 return 0;
1571 first = 0;
1572 t = t->next;
1573 } while (t);
1575 return 1;
1578 static void free_note_info(struct elf_note_info *info)
1580 struct elf_thread_core_info *threads = info->thread;
1581 while (threads) {
1582 unsigned int i;
1583 struct elf_thread_core_info *t = threads;
1584 threads = t->next;
1585 WARN_ON(t->notes[0].data && t->notes[0].data != &t->prstatus);
1586 for (i = 1; i < info->thread_notes; ++i)
1587 kfree(t->notes[i].data);
1588 kfree(t);
1590 kfree(info->psinfo.data);
1593 #else
1595 /* Here is the structure in which status of each thread is captured. */
1596 struct elf_thread_status
1598 struct list_head list;
1599 struct elf_prstatus prstatus; /* NT_PRSTATUS */
1600 elf_fpregset_t fpu; /* NT_PRFPREG */
1601 struct task_struct *thread;
1602 #ifdef ELF_CORE_COPY_XFPREGS
1603 elf_fpxregset_t xfpu; /* ELF_CORE_XFPREG_TYPE */
1604 #endif
1605 struct memelfnote notes[3];
1606 int num_notes;
1610 * In order to add the specific thread information for the elf file format,
1611 * we need to keep a linked list of every threads pr_status and then create
1612 * a single section for them in the final core file.
1614 static int elf_dump_thread_status(long signr, struct elf_thread_status *t)
1616 int sz = 0;
1617 struct task_struct *p = t->thread;
1618 t->num_notes = 0;
1620 fill_prstatus(&t->prstatus, p, signr);
1621 elf_core_copy_task_regs(p, &t->prstatus.pr_reg);
1623 fill_note(&t->notes[0], "CORE", NT_PRSTATUS, sizeof(t->prstatus),
1624 &(t->prstatus));
1625 t->num_notes++;
1626 sz += notesize(&t->notes[0]);
1628 if ((t->prstatus.pr_fpvalid = elf_core_copy_task_fpregs(p, NULL,
1629 &t->fpu))) {
1630 fill_note(&t->notes[1], "CORE", NT_PRFPREG, sizeof(t->fpu),
1631 &(t->fpu));
1632 t->num_notes++;
1633 sz += notesize(&t->notes[1]);
1636 #ifdef ELF_CORE_COPY_XFPREGS
1637 if (elf_core_copy_task_xfpregs(p, &t->xfpu)) {
1638 fill_note(&t->notes[2], "LINUX", ELF_CORE_XFPREG_TYPE,
1639 sizeof(t->xfpu), &t->xfpu);
1640 t->num_notes++;
1641 sz += notesize(&t->notes[2]);
1643 #endif
1644 return sz;
1647 struct elf_note_info {
1648 struct memelfnote *notes;
1649 struct elf_prstatus *prstatus; /* NT_PRSTATUS */
1650 struct elf_prpsinfo *psinfo; /* NT_PRPSINFO */
1651 struct list_head thread_list;
1652 elf_fpregset_t *fpu;
1653 #ifdef ELF_CORE_COPY_XFPREGS
1654 elf_fpxregset_t *xfpu;
1655 #endif
1656 int thread_status_size;
1657 int numnote;
1660 static int elf_note_info_init(struct elf_note_info *info)
1662 memset(info, 0, sizeof(*info));
1663 INIT_LIST_HEAD(&info->thread_list);
1665 /* Allocate space for six ELF notes */
1666 info->notes = kmalloc(6 * sizeof(struct memelfnote), GFP_KERNEL);
1667 if (!info->notes)
1668 return 0;
1669 info->psinfo = kmalloc(sizeof(*info->psinfo), GFP_KERNEL);
1670 if (!info->psinfo)
1671 goto notes_free;
1672 info->prstatus = kmalloc(sizeof(*info->prstatus), GFP_KERNEL);
1673 if (!info->prstatus)
1674 goto psinfo_free;
1675 info->fpu = kmalloc(sizeof(*info->fpu), GFP_KERNEL);
1676 if (!info->fpu)
1677 goto prstatus_free;
1678 #ifdef ELF_CORE_COPY_XFPREGS
1679 info->xfpu = kmalloc(sizeof(*info->xfpu), GFP_KERNEL);
1680 if (!info->xfpu)
1681 goto fpu_free;
1682 #endif
1683 return 1;
1684 #ifdef ELF_CORE_COPY_XFPREGS
1685 fpu_free:
1686 kfree(info->fpu);
1687 #endif
1688 prstatus_free:
1689 kfree(info->prstatus);
1690 psinfo_free:
1691 kfree(info->psinfo);
1692 notes_free:
1693 kfree(info->notes);
1694 return 0;
1697 static int fill_note_info(struct elfhdr *elf, int phdrs,
1698 struct elf_note_info *info,
1699 long signr, struct pt_regs *regs)
1701 struct list_head *t;
1703 if (!elf_note_info_init(info))
1704 return 0;
1706 if (signr) {
1707 struct core_thread *ct;
1708 struct elf_thread_status *ets;
1710 for (ct = current->mm->core_state->dumper.next;
1711 ct; ct = ct->next) {
1712 ets = kzalloc(sizeof(*ets), GFP_KERNEL);
1713 if (!ets)
1714 return 0;
1716 ets->thread = ct->task;
1717 list_add(&ets->list, &info->thread_list);
1720 list_for_each(t, &info->thread_list) {
1721 int sz;
1723 ets = list_entry(t, struct elf_thread_status, list);
1724 sz = elf_dump_thread_status(signr, ets);
1725 info->thread_status_size += sz;
1728 /* now collect the dump for the current */
1729 memset(info->prstatus, 0, sizeof(*info->prstatus));
1730 fill_prstatus(info->prstatus, current, signr);
1731 elf_core_copy_regs(&info->prstatus->pr_reg, regs);
1733 /* Set up header */
1734 fill_elf_header(elf, phdrs, ELF_ARCH, ELF_CORE_EFLAGS, ELF_OSABI);
1737 * Set up the notes in similar form to SVR4 core dumps made
1738 * with info from their /proc.
1741 fill_note(info->notes + 0, "CORE", NT_PRSTATUS,
1742 sizeof(*info->prstatus), info->prstatus);
1743 fill_psinfo(info->psinfo, current->group_leader, current->mm);
1744 fill_note(info->notes + 1, "CORE", NT_PRPSINFO,
1745 sizeof(*info->psinfo), info->psinfo);
1747 info->numnote = 2;
1749 fill_auxv_note(&info->notes[info->numnote++], current->mm);
1751 /* Try to dump the FPU. */
1752 info->prstatus->pr_fpvalid = elf_core_copy_task_fpregs(current, regs,
1753 info->fpu);
1754 if (info->prstatus->pr_fpvalid)
1755 fill_note(info->notes + info->numnote++,
1756 "CORE", NT_PRFPREG, sizeof(*info->fpu), info->fpu);
1757 #ifdef ELF_CORE_COPY_XFPREGS
1758 if (elf_core_copy_task_xfpregs(current, info->xfpu))
1759 fill_note(info->notes + info->numnote++,
1760 "LINUX", ELF_CORE_XFPREG_TYPE,
1761 sizeof(*info->xfpu), info->xfpu);
1762 #endif
1764 return 1;
1767 static size_t get_note_info_size(struct elf_note_info *info)
1769 int sz = 0;
1770 int i;
1772 for (i = 0; i < info->numnote; i++)
1773 sz += notesize(info->notes + i);
1775 sz += info->thread_status_size;
1777 return sz;
1780 static int write_note_info(struct elf_note_info *info,
1781 struct file *file, loff_t *foffset)
1783 int i;
1784 struct list_head *t;
1786 for (i = 0; i < info->numnote; i++)
1787 if (!writenote(info->notes + i, file, foffset))
1788 return 0;
1790 /* write out the thread status notes section */
1791 list_for_each(t, &info->thread_list) {
1792 struct elf_thread_status *tmp =
1793 list_entry(t, struct elf_thread_status, list);
1795 for (i = 0; i < tmp->num_notes; i++)
1796 if (!writenote(&tmp->notes[i], file, foffset))
1797 return 0;
1800 return 1;
1803 static void free_note_info(struct elf_note_info *info)
1805 while (!list_empty(&info->thread_list)) {
1806 struct list_head *tmp = info->thread_list.next;
1807 list_del(tmp);
1808 kfree(list_entry(tmp, struct elf_thread_status, list));
1811 kfree(info->prstatus);
1812 kfree(info->psinfo);
1813 kfree(info->notes);
1814 kfree(info->fpu);
1815 #ifdef ELF_CORE_COPY_XFPREGS
1816 kfree(info->xfpu);
1817 #endif
1820 #endif
1822 static struct vm_area_struct *first_vma(struct task_struct *tsk,
1823 struct vm_area_struct *gate_vma)
1825 struct vm_area_struct *ret = tsk->mm->mmap;
1827 if (ret)
1828 return ret;
1829 return gate_vma;
1832 * Helper function for iterating across a vma list. It ensures that the caller
1833 * will visit `gate_vma' prior to terminating the search.
1835 static struct vm_area_struct *next_vma(struct vm_area_struct *this_vma,
1836 struct vm_area_struct *gate_vma)
1838 struct vm_area_struct *ret;
1840 ret = this_vma->vm_next;
1841 if (ret)
1842 return ret;
1843 if (this_vma == gate_vma)
1844 return NULL;
1845 return gate_vma;
1848 static void fill_extnum_info(struct elfhdr *elf, struct elf_shdr *shdr4extnum,
1849 elf_addr_t e_shoff, int segs)
1851 elf->e_shoff = e_shoff;
1852 elf->e_shentsize = sizeof(*shdr4extnum);
1853 elf->e_shnum = 1;
1854 elf->e_shstrndx = SHN_UNDEF;
1856 memset(shdr4extnum, 0, sizeof(*shdr4extnum));
1858 shdr4extnum->sh_type = SHT_NULL;
1859 shdr4extnum->sh_size = elf->e_shnum;
1860 shdr4extnum->sh_link = elf->e_shstrndx;
1861 shdr4extnum->sh_info = segs;
1864 static size_t elf_core_vma_data_size(struct vm_area_struct *gate_vma,
1865 unsigned long mm_flags)
1867 struct vm_area_struct *vma;
1868 size_t size = 0;
1870 for (vma = first_vma(current, gate_vma); vma != NULL;
1871 vma = next_vma(vma, gate_vma))
1872 size += vma_dump_size(vma, mm_flags);
1873 return size;
1877 * Actual dumper
1879 * This is a two-pass process; first we find the offsets of the bits,
1880 * and then they are actually written out. If we run out of core limit
1881 * we just truncate.
1883 static int elf_core_dump(struct coredump_params *cprm)
1885 int has_dumped = 0;
1886 mm_segment_t fs;
1887 int segs;
1888 size_t size = 0;
1889 struct vm_area_struct *vma, *gate_vma;
1890 struct elfhdr *elf = NULL;
1891 loff_t offset = 0, dataoff, foffset;
1892 struct elf_note_info info;
1893 struct elf_phdr *phdr4note = NULL;
1894 struct elf_shdr *shdr4extnum = NULL;
1895 Elf_Half e_phnum;
1896 elf_addr_t e_shoff;
1899 * We no longer stop all VM operations.
1901 * This is because those proceses that could possibly change map_count
1902 * or the mmap / vma pages are now blocked in do_exit on current
1903 * finishing this core dump.
1905 * Only ptrace can touch these memory addresses, but it doesn't change
1906 * the map_count or the pages allocated. So no possibility of crashing
1907 * exists while dumping the mm->vm_next areas to the core file.
1910 /* alloc memory for large data structures: too large to be on stack */
1911 elf = kmalloc(sizeof(*elf), GFP_KERNEL);
1912 if (!elf)
1913 goto out;
1915 * The number of segs are recored into ELF header as 16bit value.
1916 * Please check DEFAULT_MAX_MAP_COUNT definition when you modify here.
1918 segs = current->mm->map_count;
1919 segs += elf_core_extra_phdrs();
1921 gate_vma = get_gate_vma(current->mm);
1922 if (gate_vma != NULL)
1923 segs++;
1925 /* for notes section */
1926 segs++;
1928 /* If segs > PN_XNUM(0xffff), then e_phnum overflows. To avoid
1929 * this, kernel supports extended numbering. Have a look at
1930 * include/linux/elf.h for further information. */
1931 e_phnum = segs > PN_XNUM ? PN_XNUM : segs;
1934 * Collect all the non-memory information about the process for the
1935 * notes. This also sets up the file header.
1937 if (!fill_note_info(elf, e_phnum, &info, cprm->signr, cprm->regs))
1938 goto cleanup;
1940 has_dumped = 1;
1941 current->flags |= PF_DUMPCORE;
1943 fs = get_fs();
1944 set_fs(KERNEL_DS);
1946 offset += sizeof(*elf); /* Elf header */
1947 offset += segs * sizeof(struct elf_phdr); /* Program headers */
1948 foffset = offset;
1950 /* Write notes phdr entry */
1952 size_t sz = get_note_info_size(&info);
1954 sz += elf_coredump_extra_notes_size();
1956 phdr4note = kmalloc(sizeof(*phdr4note), GFP_KERNEL);
1957 if (!phdr4note)
1958 goto end_coredump;
1960 fill_elf_note_phdr(phdr4note, sz, offset);
1961 offset += sz;
1964 dataoff = offset = roundup(offset, ELF_EXEC_PAGESIZE);
1966 offset += elf_core_vma_data_size(gate_vma, cprm->mm_flags);
1967 offset += elf_core_extra_data_size();
1968 e_shoff = offset;
1970 if (e_phnum == PN_XNUM) {
1971 shdr4extnum = kmalloc(sizeof(*shdr4extnum), GFP_KERNEL);
1972 if (!shdr4extnum)
1973 goto end_coredump;
1974 fill_extnum_info(elf, shdr4extnum, e_shoff, segs);
1977 offset = dataoff;
1979 size += sizeof(*elf);
1980 if (size > cprm->limit || !dump_write(cprm->file, elf, sizeof(*elf)))
1981 goto end_coredump;
1983 size += sizeof(*phdr4note);
1984 if (size > cprm->limit
1985 || !dump_write(cprm->file, phdr4note, sizeof(*phdr4note)))
1986 goto end_coredump;
1988 /* Write program headers for segments dump */
1989 for (vma = first_vma(current, gate_vma); vma != NULL;
1990 vma = next_vma(vma, gate_vma)) {
1991 struct elf_phdr phdr;
1993 phdr.p_type = PT_LOAD;
1994 phdr.p_offset = offset;
1995 phdr.p_vaddr = vma->vm_start;
1996 phdr.p_paddr = 0;
1997 phdr.p_filesz = vma_dump_size(vma, cprm->mm_flags);
1998 phdr.p_memsz = vma->vm_end - vma->vm_start;
1999 offset += phdr.p_filesz;
2000 phdr.p_flags = vma->vm_flags & VM_READ ? PF_R : 0;
2001 if (vma->vm_flags & VM_WRITE)
2002 phdr.p_flags |= PF_W;
2003 if (vma->vm_flags & VM_EXEC)
2004 phdr.p_flags |= PF_X;
2005 phdr.p_align = ELF_EXEC_PAGESIZE;
2007 size += sizeof(phdr);
2008 if (size > cprm->limit
2009 || !dump_write(cprm->file, &phdr, sizeof(phdr)))
2010 goto end_coredump;
2013 if (!elf_core_write_extra_phdrs(cprm->file, offset, &size, cprm->limit))
2014 goto end_coredump;
2016 /* write out the notes section */
2017 if (!write_note_info(&info, cprm->file, &foffset))
2018 goto end_coredump;
2020 if (elf_coredump_extra_notes_write(cprm->file, &foffset))
2021 goto end_coredump;
2023 /* Align to page */
2024 if (!dump_seek(cprm->file, dataoff - foffset))
2025 goto end_coredump;
2027 for (vma = first_vma(current, gate_vma); vma != NULL;
2028 vma = next_vma(vma, gate_vma)) {
2029 unsigned long addr;
2030 unsigned long end;
2032 end = vma->vm_start + vma_dump_size(vma, cprm->mm_flags);
2034 for (addr = vma->vm_start; addr < end; addr += PAGE_SIZE) {
2035 struct page *page;
2036 int stop;
2038 page = get_dump_page(addr);
2039 if (page) {
2040 void *kaddr = kmap(page);
2041 stop = ((size += PAGE_SIZE) > cprm->limit) ||
2042 !dump_write(cprm->file, kaddr,
2043 PAGE_SIZE);
2044 kunmap(page);
2045 page_cache_release(page);
2046 } else
2047 stop = !dump_seek(cprm->file, PAGE_SIZE);
2048 if (stop)
2049 goto end_coredump;
2053 if (!elf_core_write_extra_data(cprm->file, &size, cprm->limit))
2054 goto end_coredump;
2056 if (e_phnum == PN_XNUM) {
2057 size += sizeof(*shdr4extnum);
2058 if (size > cprm->limit
2059 || !dump_write(cprm->file, shdr4extnum,
2060 sizeof(*shdr4extnum)))
2061 goto end_coredump;
2064 end_coredump:
2065 set_fs(fs);
2067 cleanup:
2068 free_note_info(&info);
2069 kfree(shdr4extnum);
2070 kfree(phdr4note);
2071 kfree(elf);
2072 out:
2073 return has_dumped;
2076 #endif /* CONFIG_ELF_CORE */
2078 static int __init init_elf_binfmt(void)
2080 return register_binfmt(&elf_format);
2083 static void __exit exit_elf_binfmt(void)
2085 /* Remove the COFF and ELF loaders. */
2086 unregister_binfmt(&elf_format);
2089 core_initcall(init_elf_binfmt);
2090 module_exit(exit_elf_binfmt);
2091 MODULE_LICENSE("GPL");