percpu: add __percpu for sparse
[linux-2.6/kvm.git] / fs / binfmt_elf.c
blobfd5b2ea5d2993bbafa4b370fee3aba3f172577c0
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 <asm/uaccess.h>
35 #include <asm/param.h>
36 #include <asm/page.h>
38 static int load_elf_binary(struct linux_binprm *bprm, struct pt_regs *regs);
39 static int load_elf_library(struct file *);
40 static unsigned long elf_map(struct file *, unsigned long, struct elf_phdr *,
41 int, int, unsigned long);
44 * If we don't support core dumping, then supply a NULL so we
45 * don't even try.
47 #ifdef CONFIG_ELF_CORE
48 static int elf_core_dump(struct coredump_params *cprm);
49 #else
50 #define elf_core_dump NULL
51 #endif
53 #if ELF_EXEC_PAGESIZE > PAGE_SIZE
54 #define ELF_MIN_ALIGN ELF_EXEC_PAGESIZE
55 #else
56 #define ELF_MIN_ALIGN PAGE_SIZE
57 #endif
59 #ifndef ELF_CORE_EFLAGS
60 #define ELF_CORE_EFLAGS 0
61 #endif
63 #define ELF_PAGESTART(_v) ((_v) & ~(unsigned long)(ELF_MIN_ALIGN-1))
64 #define ELF_PAGEOFFSET(_v) ((_v) & (ELF_MIN_ALIGN-1))
65 #define ELF_PAGEALIGN(_v) (((_v) + ELF_MIN_ALIGN - 1) & ~(ELF_MIN_ALIGN - 1))
67 static struct linux_binfmt elf_format = {
68 .module = THIS_MODULE,
69 .load_binary = load_elf_binary,
70 .load_shlib = load_elf_library,
71 .core_dump = elf_core_dump,
72 .min_coredump = ELF_EXEC_PAGESIZE,
73 .hasvdso = 1
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 #ifndef elf_map
320 static unsigned long elf_map(struct file *filep, unsigned long addr,
321 struct elf_phdr *eppnt, int prot, int type,
322 unsigned long total_size)
324 unsigned long map_addr;
325 unsigned long size = eppnt->p_filesz + ELF_PAGEOFFSET(eppnt->p_vaddr);
326 unsigned long off = eppnt->p_offset - ELF_PAGEOFFSET(eppnt->p_vaddr);
327 addr = ELF_PAGESTART(addr);
328 size = ELF_PAGEALIGN(size);
330 /* mmap() will return -EINVAL if given a zero size, but a
331 * segment with zero filesize is perfectly valid */
332 if (!size)
333 return addr;
335 down_write(&current->mm->mmap_sem);
337 * total_size is the size of the ELF (interpreter) image.
338 * The _first_ mmap needs to know the full size, otherwise
339 * randomization might put this image into an overlapping
340 * position with the ELF binary image. (since size < total_size)
341 * So we first map the 'big' image - and unmap the remainder at
342 * the end. (which unmap is needed for ELF images with holes.)
344 if (total_size) {
345 total_size = ELF_PAGEALIGN(total_size);
346 map_addr = do_mmap(filep, addr, total_size, prot, type, off);
347 if (!BAD_ADDR(map_addr))
348 do_munmap(current->mm, map_addr+size, total_size-size);
349 } else
350 map_addr = do_mmap(filep, addr, size, prot, type, off);
352 up_write(&current->mm->mmap_sem);
353 return(map_addr);
356 #endif /* !elf_map */
358 static unsigned long total_mapping_size(struct elf_phdr *cmds, int nr)
360 int i, first_idx = -1, last_idx = -1;
362 for (i = 0; i < nr; i++) {
363 if (cmds[i].p_type == PT_LOAD) {
364 last_idx = i;
365 if (first_idx == -1)
366 first_idx = i;
369 if (first_idx == -1)
370 return 0;
372 return cmds[last_idx].p_vaddr + cmds[last_idx].p_memsz -
373 ELF_PAGESTART(cmds[first_idx].p_vaddr);
377 /* This is much more generalized than the library routine read function,
378 so we keep this separate. Technically the library read function
379 is only provided so that we can read a.out libraries that have
380 an ELF header */
382 static unsigned long load_elf_interp(struct elfhdr *interp_elf_ex,
383 struct file *interpreter, unsigned long *interp_map_addr,
384 unsigned long no_base)
386 struct elf_phdr *elf_phdata;
387 struct elf_phdr *eppnt;
388 unsigned long load_addr = 0;
389 int load_addr_set = 0;
390 unsigned long last_bss = 0, elf_bss = 0;
391 unsigned long error = ~0UL;
392 unsigned long total_size;
393 int retval, i, size;
395 /* First of all, some simple consistency checks */
396 if (interp_elf_ex->e_type != ET_EXEC &&
397 interp_elf_ex->e_type != ET_DYN)
398 goto out;
399 if (!elf_check_arch(interp_elf_ex))
400 goto out;
401 if (!interpreter->f_op || !interpreter->f_op->mmap)
402 goto out;
405 * If the size of this structure has changed, then punt, since
406 * we will be doing the wrong thing.
408 if (interp_elf_ex->e_phentsize != sizeof(struct elf_phdr))
409 goto out;
410 if (interp_elf_ex->e_phnum < 1 ||
411 interp_elf_ex->e_phnum > 65536U / sizeof(struct elf_phdr))
412 goto out;
414 /* Now read in all of the header information */
415 size = sizeof(struct elf_phdr) * interp_elf_ex->e_phnum;
416 if (size > ELF_MIN_ALIGN)
417 goto out;
418 elf_phdata = kmalloc(size, GFP_KERNEL);
419 if (!elf_phdata)
420 goto out;
422 retval = kernel_read(interpreter, interp_elf_ex->e_phoff,
423 (char *)elf_phdata,size);
424 error = -EIO;
425 if (retval != size) {
426 if (retval < 0)
427 error = retval;
428 goto out_close;
431 total_size = total_mapping_size(elf_phdata, interp_elf_ex->e_phnum);
432 if (!total_size) {
433 error = -EINVAL;
434 goto out_close;
437 eppnt = elf_phdata;
438 for (i = 0; i < interp_elf_ex->e_phnum; i++, eppnt++) {
439 if (eppnt->p_type == PT_LOAD) {
440 int elf_type = MAP_PRIVATE | MAP_DENYWRITE;
441 int elf_prot = 0;
442 unsigned long vaddr = 0;
443 unsigned long k, map_addr;
445 if (eppnt->p_flags & PF_R)
446 elf_prot = PROT_READ;
447 if (eppnt->p_flags & PF_W)
448 elf_prot |= PROT_WRITE;
449 if (eppnt->p_flags & PF_X)
450 elf_prot |= PROT_EXEC;
451 vaddr = eppnt->p_vaddr;
452 if (interp_elf_ex->e_type == ET_EXEC || load_addr_set)
453 elf_type |= MAP_FIXED;
454 else if (no_base && interp_elf_ex->e_type == ET_DYN)
455 load_addr = -vaddr;
457 map_addr = elf_map(interpreter, load_addr + vaddr,
458 eppnt, elf_prot, elf_type, total_size);
459 total_size = 0;
460 if (!*interp_map_addr)
461 *interp_map_addr = map_addr;
462 error = map_addr;
463 if (BAD_ADDR(map_addr))
464 goto out_close;
466 if (!load_addr_set &&
467 interp_elf_ex->e_type == ET_DYN) {
468 load_addr = map_addr - ELF_PAGESTART(vaddr);
469 load_addr_set = 1;
473 * Check to see if the section's size will overflow the
474 * allowed task size. Note that p_filesz must always be
475 * <= p_memsize so it's only necessary to check p_memsz.
477 k = load_addr + eppnt->p_vaddr;
478 if (BAD_ADDR(k) ||
479 eppnt->p_filesz > eppnt->p_memsz ||
480 eppnt->p_memsz > TASK_SIZE ||
481 TASK_SIZE - eppnt->p_memsz < k) {
482 error = -ENOMEM;
483 goto out_close;
487 * Find the end of the file mapping for this phdr, and
488 * keep track of the largest address we see for this.
490 k = load_addr + eppnt->p_vaddr + eppnt->p_filesz;
491 if (k > elf_bss)
492 elf_bss = k;
495 * Do the same thing for the memory mapping - between
496 * elf_bss and last_bss is the bss section.
498 k = load_addr + eppnt->p_memsz + eppnt->p_vaddr;
499 if (k > last_bss)
500 last_bss = k;
504 if (last_bss > elf_bss) {
506 * Now fill out the bss section. First pad the last page up
507 * to the page boundary, and then perform a mmap to make sure
508 * that there are zero-mapped pages up to and including the
509 * last bss page.
511 if (padzero(elf_bss)) {
512 error = -EFAULT;
513 goto out_close;
516 /* What we have mapped so far */
517 elf_bss = ELF_PAGESTART(elf_bss + ELF_MIN_ALIGN - 1);
519 /* Map the last of the bss segment */
520 down_write(&current->mm->mmap_sem);
521 error = do_brk(elf_bss, last_bss - elf_bss);
522 up_write(&current->mm->mmap_sem);
523 if (BAD_ADDR(error))
524 goto out_close;
527 error = load_addr;
529 out_close:
530 kfree(elf_phdata);
531 out:
532 return error;
536 * These are the functions used to load ELF style executables and shared
537 * libraries. There is no binary dependent code anywhere else.
540 #define INTERPRETER_NONE 0
541 #define INTERPRETER_ELF 2
543 #ifndef STACK_RND_MASK
544 #define STACK_RND_MASK (0x7ff >> (PAGE_SHIFT - 12)) /* 8MB of VA */
545 #endif
547 static unsigned long randomize_stack_top(unsigned long stack_top)
549 unsigned int random_variable = 0;
551 if ((current->flags & PF_RANDOMIZE) &&
552 !(current->personality & ADDR_NO_RANDOMIZE)) {
553 random_variable = get_random_int() & STACK_RND_MASK;
554 random_variable <<= PAGE_SHIFT;
556 #ifdef CONFIG_STACK_GROWSUP
557 return PAGE_ALIGN(stack_top) + random_variable;
558 #else
559 return PAGE_ALIGN(stack_top) - random_variable;
560 #endif
563 static int load_elf_binary(struct linux_binprm *bprm, struct pt_regs *regs)
565 struct file *interpreter = NULL; /* to shut gcc up */
566 unsigned long load_addr = 0, load_bias = 0;
567 int load_addr_set = 0;
568 char * elf_interpreter = NULL;
569 unsigned long error;
570 struct elf_phdr *elf_ppnt, *elf_phdata;
571 unsigned long elf_bss, elf_brk;
572 int retval, i;
573 unsigned int size;
574 unsigned long elf_entry;
575 unsigned long interp_load_addr = 0;
576 unsigned long start_code, end_code, start_data, end_data;
577 unsigned long reloc_func_desc = 0;
578 int executable_stack = EXSTACK_DEFAULT;
579 unsigned long def_flags = 0;
580 struct {
581 struct elfhdr elf_ex;
582 struct elfhdr interp_elf_ex;
583 } *loc;
585 loc = kmalloc(sizeof(*loc), GFP_KERNEL);
586 if (!loc) {
587 retval = -ENOMEM;
588 goto out_ret;
591 /* Get the exec-header */
592 loc->elf_ex = *((struct elfhdr *)bprm->buf);
594 retval = -ENOEXEC;
595 /* First of all, some simple consistency checks */
596 if (memcmp(loc->elf_ex.e_ident, ELFMAG, SELFMAG) != 0)
597 goto out;
599 if (loc->elf_ex.e_type != ET_EXEC && loc->elf_ex.e_type != ET_DYN)
600 goto out;
601 if (!elf_check_arch(&loc->elf_ex))
602 goto out;
603 if (!bprm->file->f_op||!bprm->file->f_op->mmap)
604 goto out;
606 /* Now read in all of the header information */
607 if (loc->elf_ex.e_phentsize != sizeof(struct elf_phdr))
608 goto out;
609 if (loc->elf_ex.e_phnum < 1 ||
610 loc->elf_ex.e_phnum > 65536U / sizeof(struct elf_phdr))
611 goto out;
612 size = loc->elf_ex.e_phnum * sizeof(struct elf_phdr);
613 retval = -ENOMEM;
614 elf_phdata = kmalloc(size, GFP_KERNEL);
615 if (!elf_phdata)
616 goto out;
618 retval = kernel_read(bprm->file, loc->elf_ex.e_phoff,
619 (char *)elf_phdata, size);
620 if (retval != size) {
621 if (retval >= 0)
622 retval = -EIO;
623 goto out_free_ph;
626 elf_ppnt = elf_phdata;
627 elf_bss = 0;
628 elf_brk = 0;
630 start_code = ~0UL;
631 end_code = 0;
632 start_data = 0;
633 end_data = 0;
635 for (i = 0; i < loc->elf_ex.e_phnum; i++) {
636 if (elf_ppnt->p_type == PT_INTERP) {
637 /* This is the program interpreter used for
638 * shared libraries - for now assume that this
639 * is an a.out format binary
641 retval = -ENOEXEC;
642 if (elf_ppnt->p_filesz > PATH_MAX ||
643 elf_ppnt->p_filesz < 2)
644 goto out_free_ph;
646 retval = -ENOMEM;
647 elf_interpreter = kmalloc(elf_ppnt->p_filesz,
648 GFP_KERNEL);
649 if (!elf_interpreter)
650 goto out_free_ph;
652 retval = kernel_read(bprm->file, elf_ppnt->p_offset,
653 elf_interpreter,
654 elf_ppnt->p_filesz);
655 if (retval != elf_ppnt->p_filesz) {
656 if (retval >= 0)
657 retval = -EIO;
658 goto out_free_interp;
660 /* make sure path is NULL terminated */
661 retval = -ENOEXEC;
662 if (elf_interpreter[elf_ppnt->p_filesz - 1] != '\0')
663 goto out_free_interp;
665 interpreter = open_exec(elf_interpreter);
666 retval = PTR_ERR(interpreter);
667 if (IS_ERR(interpreter))
668 goto out_free_interp;
671 * If the binary is not readable then enforce
672 * mm->dumpable = 0 regardless of the interpreter's
673 * permissions.
675 if (file_permission(interpreter, MAY_READ) < 0)
676 bprm->interp_flags |= BINPRM_FLAGS_ENFORCE_NONDUMP;
678 retval = kernel_read(interpreter, 0, bprm->buf,
679 BINPRM_BUF_SIZE);
680 if (retval != BINPRM_BUF_SIZE) {
681 if (retval >= 0)
682 retval = -EIO;
683 goto out_free_dentry;
686 /* Get the exec headers */
687 loc->interp_elf_ex = *((struct elfhdr *)bprm->buf);
688 break;
690 elf_ppnt++;
693 elf_ppnt = elf_phdata;
694 for (i = 0; i < loc->elf_ex.e_phnum; i++, elf_ppnt++)
695 if (elf_ppnt->p_type == PT_GNU_STACK) {
696 if (elf_ppnt->p_flags & PF_X)
697 executable_stack = EXSTACK_ENABLE_X;
698 else
699 executable_stack = EXSTACK_DISABLE_X;
700 break;
703 /* Some simple consistency checks for the interpreter */
704 if (elf_interpreter) {
705 retval = -ELIBBAD;
706 /* Not an ELF interpreter */
707 if (memcmp(loc->interp_elf_ex.e_ident, ELFMAG, SELFMAG) != 0)
708 goto out_free_dentry;
709 /* Verify the interpreter has a valid arch */
710 if (!elf_check_arch(&loc->interp_elf_ex))
711 goto out_free_dentry;
714 /* Flush all traces of the currently running executable */
715 retval = flush_old_exec(bprm);
716 if (retval)
717 goto out_free_dentry;
719 /* OK, This is the point of no return */
720 current->flags &= ~PF_FORKNOEXEC;
721 current->mm->def_flags = def_flags;
723 /* Do this immediately, since STACK_TOP as used in setup_arg_pages
724 may depend on the personality. */
725 SET_PERSONALITY(loc->elf_ex);
726 if (elf_read_implies_exec(loc->elf_ex, executable_stack))
727 current->personality |= READ_IMPLIES_EXEC;
729 if (!(current->personality & ADDR_NO_RANDOMIZE) && randomize_va_space)
730 current->flags |= PF_RANDOMIZE;
732 setup_new_exec(bprm);
734 /* Do this so that we can load the interpreter, if need be. We will
735 change some of these later */
736 current->mm->free_area_cache = current->mm->mmap_base;
737 current->mm->cached_hole_size = 0;
738 retval = setup_arg_pages(bprm, randomize_stack_top(STACK_TOP),
739 executable_stack);
740 if (retval < 0) {
741 send_sig(SIGKILL, current, 0);
742 goto out_free_dentry;
745 current->mm->start_stack = bprm->p;
747 /* Now we do a little grungy work by mmapping the ELF image into
748 the correct location in memory. */
749 for(i = 0, elf_ppnt = elf_phdata;
750 i < loc->elf_ex.e_phnum; i++, elf_ppnt++) {
751 int elf_prot = 0, elf_flags;
752 unsigned long k, vaddr;
754 if (elf_ppnt->p_type != PT_LOAD)
755 continue;
757 if (unlikely (elf_brk > elf_bss)) {
758 unsigned long nbyte;
760 /* There was a PT_LOAD segment with p_memsz > p_filesz
761 before this one. Map anonymous pages, if needed,
762 and clear the area. */
763 retval = set_brk (elf_bss + load_bias,
764 elf_brk + load_bias);
765 if (retval) {
766 send_sig(SIGKILL, current, 0);
767 goto out_free_dentry;
769 nbyte = ELF_PAGEOFFSET(elf_bss);
770 if (nbyte) {
771 nbyte = ELF_MIN_ALIGN - nbyte;
772 if (nbyte > elf_brk - elf_bss)
773 nbyte = elf_brk - elf_bss;
774 if (clear_user((void __user *)elf_bss +
775 load_bias, nbyte)) {
777 * This bss-zeroing can fail if the ELF
778 * file specifies odd protections. So
779 * we don't check the return value
785 if (elf_ppnt->p_flags & PF_R)
786 elf_prot |= PROT_READ;
787 if (elf_ppnt->p_flags & PF_W)
788 elf_prot |= PROT_WRITE;
789 if (elf_ppnt->p_flags & PF_X)
790 elf_prot |= PROT_EXEC;
792 elf_flags = MAP_PRIVATE | MAP_DENYWRITE | MAP_EXECUTABLE;
794 vaddr = elf_ppnt->p_vaddr;
795 if (loc->elf_ex.e_type == ET_EXEC || load_addr_set) {
796 elf_flags |= MAP_FIXED;
797 } else if (loc->elf_ex.e_type == ET_DYN) {
798 /* Try and get dynamic programs out of the way of the
799 * default mmap base, as well as whatever program they
800 * might try to exec. This is because the brk will
801 * follow the loader, and is not movable. */
802 #ifdef CONFIG_X86
803 load_bias = 0;
804 #else
805 load_bias = ELF_PAGESTART(ELF_ET_DYN_BASE - vaddr);
806 #endif
809 error = elf_map(bprm->file, load_bias + vaddr, elf_ppnt,
810 elf_prot, elf_flags, 0);
811 if (BAD_ADDR(error)) {
812 send_sig(SIGKILL, current, 0);
813 retval = IS_ERR((void *)error) ?
814 PTR_ERR((void*)error) : -EINVAL;
815 goto out_free_dentry;
818 if (!load_addr_set) {
819 load_addr_set = 1;
820 load_addr = (elf_ppnt->p_vaddr - elf_ppnt->p_offset);
821 if (loc->elf_ex.e_type == ET_DYN) {
822 load_bias += error -
823 ELF_PAGESTART(load_bias + vaddr);
824 load_addr += load_bias;
825 reloc_func_desc = load_bias;
828 k = elf_ppnt->p_vaddr;
829 if (k < start_code)
830 start_code = k;
831 if (start_data < k)
832 start_data = k;
835 * Check to see if the section's size will overflow the
836 * allowed task size. Note that p_filesz must always be
837 * <= p_memsz so it is only necessary to check p_memsz.
839 if (BAD_ADDR(k) || elf_ppnt->p_filesz > elf_ppnt->p_memsz ||
840 elf_ppnt->p_memsz > TASK_SIZE ||
841 TASK_SIZE - elf_ppnt->p_memsz < k) {
842 /* set_brk can never work. Avoid overflows. */
843 send_sig(SIGKILL, current, 0);
844 retval = -EINVAL;
845 goto out_free_dentry;
848 k = elf_ppnt->p_vaddr + elf_ppnt->p_filesz;
850 if (k > elf_bss)
851 elf_bss = k;
852 if ((elf_ppnt->p_flags & PF_X) && end_code < k)
853 end_code = k;
854 if (end_data < k)
855 end_data = k;
856 k = elf_ppnt->p_vaddr + elf_ppnt->p_memsz;
857 if (k > elf_brk)
858 elf_brk = k;
861 loc->elf_ex.e_entry += load_bias;
862 elf_bss += load_bias;
863 elf_brk += load_bias;
864 start_code += load_bias;
865 end_code += load_bias;
866 start_data += load_bias;
867 end_data += load_bias;
869 /* Calling set_brk effectively mmaps the pages that we need
870 * for the bss and break sections. We must do this before
871 * mapping in the interpreter, to make sure it doesn't wind
872 * up getting placed where the bss needs to go.
874 retval = set_brk(elf_bss, elf_brk);
875 if (retval) {
876 send_sig(SIGKILL, current, 0);
877 goto out_free_dentry;
879 if (likely(elf_bss != elf_brk) && unlikely(padzero(elf_bss))) {
880 send_sig(SIGSEGV, current, 0);
881 retval = -EFAULT; /* Nobody gets to see this, but.. */
882 goto out_free_dentry;
885 if (elf_interpreter) {
886 unsigned long uninitialized_var(interp_map_addr);
888 elf_entry = load_elf_interp(&loc->interp_elf_ex,
889 interpreter,
890 &interp_map_addr,
891 load_bias);
892 if (!IS_ERR((void *)elf_entry)) {
894 * load_elf_interp() returns relocation
895 * adjustment
897 interp_load_addr = elf_entry;
898 elf_entry += loc->interp_elf_ex.e_entry;
900 if (BAD_ADDR(elf_entry)) {
901 force_sig(SIGSEGV, current);
902 retval = IS_ERR((void *)elf_entry) ?
903 (int)elf_entry : -EINVAL;
904 goto out_free_dentry;
906 reloc_func_desc = interp_load_addr;
908 allow_write_access(interpreter);
909 fput(interpreter);
910 kfree(elf_interpreter);
911 } else {
912 elf_entry = loc->elf_ex.e_entry;
913 if (BAD_ADDR(elf_entry)) {
914 force_sig(SIGSEGV, current);
915 retval = -EINVAL;
916 goto out_free_dentry;
920 kfree(elf_phdata);
922 set_binfmt(&elf_format);
924 #ifdef ARCH_HAS_SETUP_ADDITIONAL_PAGES
925 retval = arch_setup_additional_pages(bprm, !!elf_interpreter);
926 if (retval < 0) {
927 send_sig(SIGKILL, current, 0);
928 goto out;
930 #endif /* ARCH_HAS_SETUP_ADDITIONAL_PAGES */
932 install_exec_creds(bprm);
933 current->flags &= ~PF_FORKNOEXEC;
934 retval = create_elf_tables(bprm, &loc->elf_ex,
935 load_addr, interp_load_addr);
936 if (retval < 0) {
937 send_sig(SIGKILL, current, 0);
938 goto out;
940 /* N.B. passed_fileno might not be initialized? */
941 current->mm->end_code = end_code;
942 current->mm->start_code = start_code;
943 current->mm->start_data = start_data;
944 current->mm->end_data = end_data;
945 current->mm->start_stack = bprm->p;
947 #ifdef arch_randomize_brk
948 if ((current->flags & PF_RANDOMIZE) && (randomize_va_space > 1))
949 current->mm->brk = current->mm->start_brk =
950 arch_randomize_brk(current->mm);
951 #endif
953 if (current->personality & MMAP_PAGE_ZERO) {
954 /* Why this, you ask??? Well SVr4 maps page 0 as read-only,
955 and some applications "depend" upon this behavior.
956 Since we do not have the power to recompile these, we
957 emulate the SVr4 behavior. Sigh. */
958 down_write(&current->mm->mmap_sem);
959 error = do_mmap(NULL, 0, PAGE_SIZE, PROT_READ | PROT_EXEC,
960 MAP_FIXED | MAP_PRIVATE, 0);
961 up_write(&current->mm->mmap_sem);
964 #ifdef ELF_PLAT_INIT
966 * The ABI may specify that certain registers be set up in special
967 * ways (on i386 %edx is the address of a DT_FINI function, for
968 * example. In addition, it may also specify (eg, PowerPC64 ELF)
969 * that the e_entry field is the address of the function descriptor
970 * for the startup routine, rather than the address of the startup
971 * routine itself. This macro performs whatever initialization to
972 * the regs structure is required as well as any relocations to the
973 * function descriptor entries when executing dynamically links apps.
975 ELF_PLAT_INIT(regs, reloc_func_desc);
976 #endif
978 start_thread(regs, elf_entry, bprm->p);
979 retval = 0;
980 out:
981 kfree(loc);
982 out_ret:
983 return retval;
985 /* error cleanup */
986 out_free_dentry:
987 allow_write_access(interpreter);
988 if (interpreter)
989 fput(interpreter);
990 out_free_interp:
991 kfree(elf_interpreter);
992 out_free_ph:
993 kfree(elf_phdata);
994 goto out;
997 /* This is really simpleminded and specialized - we are loading an
998 a.out library that is given an ELF header. */
999 static int load_elf_library(struct file *file)
1001 struct elf_phdr *elf_phdata;
1002 struct elf_phdr *eppnt;
1003 unsigned long elf_bss, bss, len;
1004 int retval, error, i, j;
1005 struct elfhdr elf_ex;
1007 error = -ENOEXEC;
1008 retval = kernel_read(file, 0, (char *)&elf_ex, sizeof(elf_ex));
1009 if (retval != sizeof(elf_ex))
1010 goto out;
1012 if (memcmp(elf_ex.e_ident, ELFMAG, SELFMAG) != 0)
1013 goto out;
1015 /* First of all, some simple consistency checks */
1016 if (elf_ex.e_type != ET_EXEC || elf_ex.e_phnum > 2 ||
1017 !elf_check_arch(&elf_ex) || !file->f_op || !file->f_op->mmap)
1018 goto out;
1020 /* Now read in all of the header information */
1022 j = sizeof(struct elf_phdr) * elf_ex.e_phnum;
1023 /* j < ELF_MIN_ALIGN because elf_ex.e_phnum <= 2 */
1025 error = -ENOMEM;
1026 elf_phdata = kmalloc(j, GFP_KERNEL);
1027 if (!elf_phdata)
1028 goto out;
1030 eppnt = elf_phdata;
1031 error = -ENOEXEC;
1032 retval = kernel_read(file, elf_ex.e_phoff, (char *)eppnt, j);
1033 if (retval != j)
1034 goto out_free_ph;
1036 for (j = 0, i = 0; i<elf_ex.e_phnum; i++)
1037 if ((eppnt + i)->p_type == PT_LOAD)
1038 j++;
1039 if (j != 1)
1040 goto out_free_ph;
1042 while (eppnt->p_type != PT_LOAD)
1043 eppnt++;
1045 /* Now use mmap to map the library into memory. */
1046 down_write(&current->mm->mmap_sem);
1047 error = do_mmap(file,
1048 ELF_PAGESTART(eppnt->p_vaddr),
1049 (eppnt->p_filesz +
1050 ELF_PAGEOFFSET(eppnt->p_vaddr)),
1051 PROT_READ | PROT_WRITE | PROT_EXEC,
1052 MAP_FIXED | MAP_PRIVATE | MAP_DENYWRITE,
1053 (eppnt->p_offset -
1054 ELF_PAGEOFFSET(eppnt->p_vaddr)));
1055 up_write(&current->mm->mmap_sem);
1056 if (error != ELF_PAGESTART(eppnt->p_vaddr))
1057 goto out_free_ph;
1059 elf_bss = eppnt->p_vaddr + eppnt->p_filesz;
1060 if (padzero(elf_bss)) {
1061 error = -EFAULT;
1062 goto out_free_ph;
1065 len = ELF_PAGESTART(eppnt->p_filesz + eppnt->p_vaddr +
1066 ELF_MIN_ALIGN - 1);
1067 bss = eppnt->p_memsz + eppnt->p_vaddr;
1068 if (bss > len) {
1069 down_write(&current->mm->mmap_sem);
1070 do_brk(len, bss - len);
1071 up_write(&current->mm->mmap_sem);
1073 error = 0;
1075 out_free_ph:
1076 kfree(elf_phdata);
1077 out:
1078 return error;
1081 #ifdef CONFIG_ELF_CORE
1083 * ELF core dumper
1085 * Modelled on fs/exec.c:aout_core_dump()
1086 * Jeremy Fitzhardinge <jeremy@sw.oz.au>
1089 * These are the only things you should do on a core-file: use only these
1090 * functions to write out all the necessary info.
1092 static int dump_write(struct file *file, const void *addr, int nr)
1094 return file->f_op->write(file, addr, nr, &file->f_pos) == nr;
1097 static int dump_seek(struct file *file, loff_t off)
1099 if (file->f_op->llseek && file->f_op->llseek != no_llseek) {
1100 if (file->f_op->llseek(file, off, SEEK_CUR) < 0)
1101 return 0;
1102 } else {
1103 char *buf = (char *)get_zeroed_page(GFP_KERNEL);
1104 if (!buf)
1105 return 0;
1106 while (off > 0) {
1107 unsigned long n = off;
1108 if (n > PAGE_SIZE)
1109 n = PAGE_SIZE;
1110 if (!dump_write(file, buf, n))
1111 return 0;
1112 off -= n;
1114 free_page((unsigned long)buf);
1116 return 1;
1120 * Decide what to dump of a segment, part, all or none.
1122 static unsigned long vma_dump_size(struct vm_area_struct *vma,
1123 unsigned long mm_flags)
1125 #define FILTER(type) (mm_flags & (1UL << MMF_DUMP_##type))
1127 /* The vma can be set up to tell us the answer directly. */
1128 if (vma->vm_flags & VM_ALWAYSDUMP)
1129 goto whole;
1131 /* Hugetlb memory check */
1132 if (vma->vm_flags & VM_HUGETLB) {
1133 if ((vma->vm_flags & VM_SHARED) && FILTER(HUGETLB_SHARED))
1134 goto whole;
1135 if (!(vma->vm_flags & VM_SHARED) && FILTER(HUGETLB_PRIVATE))
1136 goto whole;
1139 /* Do not dump I/O mapped devices or special mappings */
1140 if (vma->vm_flags & (VM_IO | VM_RESERVED))
1141 return 0;
1143 /* By default, dump shared memory if mapped from an anonymous file. */
1144 if (vma->vm_flags & VM_SHARED) {
1145 if (vma->vm_file->f_path.dentry->d_inode->i_nlink == 0 ?
1146 FILTER(ANON_SHARED) : FILTER(MAPPED_SHARED))
1147 goto whole;
1148 return 0;
1151 /* Dump segments that have been written to. */
1152 if (vma->anon_vma && FILTER(ANON_PRIVATE))
1153 goto whole;
1154 if (vma->vm_file == NULL)
1155 return 0;
1157 if (FILTER(MAPPED_PRIVATE))
1158 goto whole;
1161 * If this looks like the beginning of a DSO or executable mapping,
1162 * check for an ELF header. If we find one, dump the first page to
1163 * aid in determining what was mapped here.
1165 if (FILTER(ELF_HEADERS) &&
1166 vma->vm_pgoff == 0 && (vma->vm_flags & VM_READ)) {
1167 u32 __user *header = (u32 __user *) vma->vm_start;
1168 u32 word;
1169 mm_segment_t fs = get_fs();
1171 * Doing it this way gets the constant folded by GCC.
1173 union {
1174 u32 cmp;
1175 char elfmag[SELFMAG];
1176 } magic;
1177 BUILD_BUG_ON(SELFMAG != sizeof word);
1178 magic.elfmag[EI_MAG0] = ELFMAG0;
1179 magic.elfmag[EI_MAG1] = ELFMAG1;
1180 magic.elfmag[EI_MAG2] = ELFMAG2;
1181 magic.elfmag[EI_MAG3] = ELFMAG3;
1183 * Switch to the user "segment" for get_user(),
1184 * then put back what elf_core_dump() had in place.
1186 set_fs(USER_DS);
1187 if (unlikely(get_user(word, header)))
1188 word = 0;
1189 set_fs(fs);
1190 if (word == magic.cmp)
1191 return PAGE_SIZE;
1194 #undef FILTER
1196 return 0;
1198 whole:
1199 return vma->vm_end - vma->vm_start;
1202 /* An ELF note in memory */
1203 struct memelfnote
1205 const char *name;
1206 int type;
1207 unsigned int datasz;
1208 void *data;
1211 static int notesize(struct memelfnote *en)
1213 int sz;
1215 sz = sizeof(struct elf_note);
1216 sz += roundup(strlen(en->name) + 1, 4);
1217 sz += roundup(en->datasz, 4);
1219 return sz;
1222 #define DUMP_WRITE(addr, nr, foffset) \
1223 do { if (!dump_write(file, (addr), (nr))) return 0; *foffset += (nr); } while(0)
1225 static int alignfile(struct file *file, loff_t *foffset)
1227 static const char buf[4] = { 0, };
1228 DUMP_WRITE(buf, roundup(*foffset, 4) - *foffset, foffset);
1229 return 1;
1232 static int writenote(struct memelfnote *men, struct file *file,
1233 loff_t *foffset)
1235 struct elf_note en;
1236 en.n_namesz = strlen(men->name) + 1;
1237 en.n_descsz = men->datasz;
1238 en.n_type = men->type;
1240 DUMP_WRITE(&en, sizeof(en), foffset);
1241 DUMP_WRITE(men->name, en.n_namesz, foffset);
1242 if (!alignfile(file, foffset))
1243 return 0;
1244 DUMP_WRITE(men->data, men->datasz, foffset);
1245 if (!alignfile(file, foffset))
1246 return 0;
1248 return 1;
1250 #undef DUMP_WRITE
1252 #define DUMP_WRITE(addr, nr) \
1253 if ((size += (nr)) > cprm->limit || \
1254 !dump_write(cprm->file, (addr), (nr))) \
1255 goto end_coredump;
1257 static void fill_elf_header(struct elfhdr *elf, int segs,
1258 u16 machine, u32 flags, u8 osabi)
1260 memset(elf, 0, sizeof(*elf));
1262 memcpy(elf->e_ident, ELFMAG, SELFMAG);
1263 elf->e_ident[EI_CLASS] = ELF_CLASS;
1264 elf->e_ident[EI_DATA] = ELF_DATA;
1265 elf->e_ident[EI_VERSION] = EV_CURRENT;
1266 elf->e_ident[EI_OSABI] = ELF_OSABI;
1268 elf->e_type = ET_CORE;
1269 elf->e_machine = machine;
1270 elf->e_version = EV_CURRENT;
1271 elf->e_phoff = sizeof(struct elfhdr);
1272 elf->e_flags = flags;
1273 elf->e_ehsize = sizeof(struct elfhdr);
1274 elf->e_phentsize = sizeof(struct elf_phdr);
1275 elf->e_phnum = segs;
1277 return;
1280 static void fill_elf_note_phdr(struct elf_phdr *phdr, int sz, loff_t offset)
1282 phdr->p_type = PT_NOTE;
1283 phdr->p_offset = offset;
1284 phdr->p_vaddr = 0;
1285 phdr->p_paddr = 0;
1286 phdr->p_filesz = sz;
1287 phdr->p_memsz = 0;
1288 phdr->p_flags = 0;
1289 phdr->p_align = 0;
1290 return;
1293 static void fill_note(struct memelfnote *note, const char *name, int type,
1294 unsigned int sz, void *data)
1296 note->name = name;
1297 note->type = type;
1298 note->datasz = sz;
1299 note->data = data;
1300 return;
1304 * fill up all the fields in prstatus from the given task struct, except
1305 * registers which need to be filled up separately.
1307 static void fill_prstatus(struct elf_prstatus *prstatus,
1308 struct task_struct *p, long signr)
1310 prstatus->pr_info.si_signo = prstatus->pr_cursig = signr;
1311 prstatus->pr_sigpend = p->pending.signal.sig[0];
1312 prstatus->pr_sighold = p->blocked.sig[0];
1313 rcu_read_lock();
1314 prstatus->pr_ppid = task_pid_vnr(rcu_dereference(p->real_parent));
1315 rcu_read_unlock();
1316 prstatus->pr_pid = task_pid_vnr(p);
1317 prstatus->pr_pgrp = task_pgrp_vnr(p);
1318 prstatus->pr_sid = task_session_vnr(p);
1319 if (thread_group_leader(p)) {
1320 struct task_cputime cputime;
1323 * This is the record for the group leader. It shows the
1324 * group-wide total, not its individual thread total.
1326 thread_group_cputime(p, &cputime);
1327 cputime_to_timeval(cputime.utime, &prstatus->pr_utime);
1328 cputime_to_timeval(cputime.stime, &prstatus->pr_stime);
1329 } else {
1330 cputime_to_timeval(p->utime, &prstatus->pr_utime);
1331 cputime_to_timeval(p->stime, &prstatus->pr_stime);
1333 cputime_to_timeval(p->signal->cutime, &prstatus->pr_cutime);
1334 cputime_to_timeval(p->signal->cstime, &prstatus->pr_cstime);
1337 static int fill_psinfo(struct elf_prpsinfo *psinfo, struct task_struct *p,
1338 struct mm_struct *mm)
1340 const struct cred *cred;
1341 unsigned int i, len;
1343 /* first copy the parameters from user space */
1344 memset(psinfo, 0, sizeof(struct elf_prpsinfo));
1346 len = mm->arg_end - mm->arg_start;
1347 if (len >= ELF_PRARGSZ)
1348 len = ELF_PRARGSZ-1;
1349 if (copy_from_user(&psinfo->pr_psargs,
1350 (const char __user *)mm->arg_start, len))
1351 return -EFAULT;
1352 for(i = 0; i < len; i++)
1353 if (psinfo->pr_psargs[i] == 0)
1354 psinfo->pr_psargs[i] = ' ';
1355 psinfo->pr_psargs[len] = 0;
1357 rcu_read_lock();
1358 psinfo->pr_ppid = task_pid_vnr(rcu_dereference(p->real_parent));
1359 rcu_read_unlock();
1360 psinfo->pr_pid = task_pid_vnr(p);
1361 psinfo->pr_pgrp = task_pgrp_vnr(p);
1362 psinfo->pr_sid = task_session_vnr(p);
1364 i = p->state ? ffz(~p->state) + 1 : 0;
1365 psinfo->pr_state = i;
1366 psinfo->pr_sname = (i > 5) ? '.' : "RSDTZW"[i];
1367 psinfo->pr_zomb = psinfo->pr_sname == 'Z';
1368 psinfo->pr_nice = task_nice(p);
1369 psinfo->pr_flag = p->flags;
1370 rcu_read_lock();
1371 cred = __task_cred(p);
1372 SET_UID(psinfo->pr_uid, cred->uid);
1373 SET_GID(psinfo->pr_gid, cred->gid);
1374 rcu_read_unlock();
1375 strncpy(psinfo->pr_fname, p->comm, sizeof(psinfo->pr_fname));
1377 return 0;
1380 static void fill_auxv_note(struct memelfnote *note, struct mm_struct *mm)
1382 elf_addr_t *auxv = (elf_addr_t *) mm->saved_auxv;
1383 int i = 0;
1385 i += 2;
1386 while (auxv[i - 2] != AT_NULL);
1387 fill_note(note, "CORE", NT_AUXV, i * sizeof(elf_addr_t), auxv);
1390 #ifdef CORE_DUMP_USE_REGSET
1391 #include <linux/regset.h>
1393 struct elf_thread_core_info {
1394 struct elf_thread_core_info *next;
1395 struct task_struct *task;
1396 struct elf_prstatus prstatus;
1397 struct memelfnote notes[0];
1400 struct elf_note_info {
1401 struct elf_thread_core_info *thread;
1402 struct memelfnote psinfo;
1403 struct memelfnote auxv;
1404 size_t size;
1405 int thread_notes;
1409 * When a regset has a writeback hook, we call it on each thread before
1410 * dumping user memory. On register window machines, this makes sure the
1411 * user memory backing the register data is up to date before we read it.
1413 static void do_thread_regset_writeback(struct task_struct *task,
1414 const struct user_regset *regset)
1416 if (regset->writeback)
1417 regset->writeback(task, regset, 1);
1420 static int fill_thread_core_info(struct elf_thread_core_info *t,
1421 const struct user_regset_view *view,
1422 long signr, size_t *total)
1424 unsigned int i;
1427 * NT_PRSTATUS is the one special case, because the regset data
1428 * goes into the pr_reg field inside the note contents, rather
1429 * than being the whole note contents. We fill the reset in here.
1430 * We assume that regset 0 is NT_PRSTATUS.
1432 fill_prstatus(&t->prstatus, t->task, signr);
1433 (void) view->regsets[0].get(t->task, &view->regsets[0],
1434 0, sizeof(t->prstatus.pr_reg),
1435 &t->prstatus.pr_reg, NULL);
1437 fill_note(&t->notes[0], "CORE", NT_PRSTATUS,
1438 sizeof(t->prstatus), &t->prstatus);
1439 *total += notesize(&t->notes[0]);
1441 do_thread_regset_writeback(t->task, &view->regsets[0]);
1444 * Each other regset might generate a note too. For each regset
1445 * that has no core_note_type or is inactive, we leave t->notes[i]
1446 * all zero and we'll know to skip writing it later.
1448 for (i = 1; i < view->n; ++i) {
1449 const struct user_regset *regset = &view->regsets[i];
1450 do_thread_regset_writeback(t->task, regset);
1451 if (regset->core_note_type &&
1452 (!regset->active || regset->active(t->task, regset))) {
1453 int ret;
1454 size_t size = regset->n * regset->size;
1455 void *data = kmalloc(size, GFP_KERNEL);
1456 if (unlikely(!data))
1457 return 0;
1458 ret = regset->get(t->task, regset,
1459 0, size, data, NULL);
1460 if (unlikely(ret))
1461 kfree(data);
1462 else {
1463 if (regset->core_note_type != NT_PRFPREG)
1464 fill_note(&t->notes[i], "LINUX",
1465 regset->core_note_type,
1466 size, data);
1467 else {
1468 t->prstatus.pr_fpvalid = 1;
1469 fill_note(&t->notes[i], "CORE",
1470 NT_PRFPREG, size, data);
1472 *total += notesize(&t->notes[i]);
1477 return 1;
1480 static int fill_note_info(struct elfhdr *elf, int phdrs,
1481 struct elf_note_info *info,
1482 long signr, struct pt_regs *regs)
1484 struct task_struct *dump_task = current;
1485 const struct user_regset_view *view = task_user_regset_view(dump_task);
1486 struct elf_thread_core_info *t;
1487 struct elf_prpsinfo *psinfo;
1488 struct core_thread *ct;
1489 unsigned int i;
1491 info->size = 0;
1492 info->thread = NULL;
1494 psinfo = kmalloc(sizeof(*psinfo), GFP_KERNEL);
1495 if (psinfo == NULL)
1496 return 0;
1498 fill_note(&info->psinfo, "CORE", NT_PRPSINFO, sizeof(*psinfo), psinfo);
1501 * Figure out how many notes we're going to need for each thread.
1503 info->thread_notes = 0;
1504 for (i = 0; i < view->n; ++i)
1505 if (view->regsets[i].core_note_type != 0)
1506 ++info->thread_notes;
1509 * Sanity check. We rely on regset 0 being in NT_PRSTATUS,
1510 * since it is our one special case.
1512 if (unlikely(info->thread_notes == 0) ||
1513 unlikely(view->regsets[0].core_note_type != NT_PRSTATUS)) {
1514 WARN_ON(1);
1515 return 0;
1519 * Initialize the ELF file header.
1521 fill_elf_header(elf, phdrs,
1522 view->e_machine, view->e_flags, view->ei_osabi);
1525 * Allocate a structure for each thread.
1527 for (ct = &dump_task->mm->core_state->dumper; ct; ct = ct->next) {
1528 t = kzalloc(offsetof(struct elf_thread_core_info,
1529 notes[info->thread_notes]),
1530 GFP_KERNEL);
1531 if (unlikely(!t))
1532 return 0;
1534 t->task = ct->task;
1535 if (ct->task == dump_task || !info->thread) {
1536 t->next = info->thread;
1537 info->thread = t;
1538 } else {
1540 * Make sure to keep the original task at
1541 * the head of the list.
1543 t->next = info->thread->next;
1544 info->thread->next = t;
1549 * Now fill in each thread's information.
1551 for (t = info->thread; t != NULL; t = t->next)
1552 if (!fill_thread_core_info(t, view, signr, &info->size))
1553 return 0;
1556 * Fill in the two process-wide notes.
1558 fill_psinfo(psinfo, dump_task->group_leader, dump_task->mm);
1559 info->size += notesize(&info->psinfo);
1561 fill_auxv_note(&info->auxv, current->mm);
1562 info->size += notesize(&info->auxv);
1564 return 1;
1567 static size_t get_note_info_size(struct elf_note_info *info)
1569 return info->size;
1573 * Write all the notes for each thread. When writing the first thread, the
1574 * process-wide notes are interleaved after the first thread-specific note.
1576 static int write_note_info(struct elf_note_info *info,
1577 struct file *file, loff_t *foffset)
1579 bool first = 1;
1580 struct elf_thread_core_info *t = info->thread;
1582 do {
1583 int i;
1585 if (!writenote(&t->notes[0], file, foffset))
1586 return 0;
1588 if (first && !writenote(&info->psinfo, file, foffset))
1589 return 0;
1590 if (first && !writenote(&info->auxv, file, foffset))
1591 return 0;
1593 for (i = 1; i < info->thread_notes; ++i)
1594 if (t->notes[i].data &&
1595 !writenote(&t->notes[i], file, foffset))
1596 return 0;
1598 first = 0;
1599 t = t->next;
1600 } while (t);
1602 return 1;
1605 static void free_note_info(struct elf_note_info *info)
1607 struct elf_thread_core_info *threads = info->thread;
1608 while (threads) {
1609 unsigned int i;
1610 struct elf_thread_core_info *t = threads;
1611 threads = t->next;
1612 WARN_ON(t->notes[0].data && t->notes[0].data != &t->prstatus);
1613 for (i = 1; i < info->thread_notes; ++i)
1614 kfree(t->notes[i].data);
1615 kfree(t);
1617 kfree(info->psinfo.data);
1620 #else
1622 /* Here is the structure in which status of each thread is captured. */
1623 struct elf_thread_status
1625 struct list_head list;
1626 struct elf_prstatus prstatus; /* NT_PRSTATUS */
1627 elf_fpregset_t fpu; /* NT_PRFPREG */
1628 struct task_struct *thread;
1629 #ifdef ELF_CORE_COPY_XFPREGS
1630 elf_fpxregset_t xfpu; /* ELF_CORE_XFPREG_TYPE */
1631 #endif
1632 struct memelfnote notes[3];
1633 int num_notes;
1637 * In order to add the specific thread information for the elf file format,
1638 * we need to keep a linked list of every threads pr_status and then create
1639 * a single section for them in the final core file.
1641 static int elf_dump_thread_status(long signr, struct elf_thread_status *t)
1643 int sz = 0;
1644 struct task_struct *p = t->thread;
1645 t->num_notes = 0;
1647 fill_prstatus(&t->prstatus, p, signr);
1648 elf_core_copy_task_regs(p, &t->prstatus.pr_reg);
1650 fill_note(&t->notes[0], "CORE", NT_PRSTATUS, sizeof(t->prstatus),
1651 &(t->prstatus));
1652 t->num_notes++;
1653 sz += notesize(&t->notes[0]);
1655 if ((t->prstatus.pr_fpvalid = elf_core_copy_task_fpregs(p, NULL,
1656 &t->fpu))) {
1657 fill_note(&t->notes[1], "CORE", NT_PRFPREG, sizeof(t->fpu),
1658 &(t->fpu));
1659 t->num_notes++;
1660 sz += notesize(&t->notes[1]);
1663 #ifdef ELF_CORE_COPY_XFPREGS
1664 if (elf_core_copy_task_xfpregs(p, &t->xfpu)) {
1665 fill_note(&t->notes[2], "LINUX", ELF_CORE_XFPREG_TYPE,
1666 sizeof(t->xfpu), &t->xfpu);
1667 t->num_notes++;
1668 sz += notesize(&t->notes[2]);
1670 #endif
1671 return sz;
1674 struct elf_note_info {
1675 struct memelfnote *notes;
1676 struct elf_prstatus *prstatus; /* NT_PRSTATUS */
1677 struct elf_prpsinfo *psinfo; /* NT_PRPSINFO */
1678 struct list_head thread_list;
1679 elf_fpregset_t *fpu;
1680 #ifdef ELF_CORE_COPY_XFPREGS
1681 elf_fpxregset_t *xfpu;
1682 #endif
1683 int thread_status_size;
1684 int numnote;
1687 static int elf_note_info_init(struct elf_note_info *info)
1689 memset(info, 0, sizeof(*info));
1690 INIT_LIST_HEAD(&info->thread_list);
1692 /* Allocate space for six ELF notes */
1693 info->notes = kmalloc(6 * sizeof(struct memelfnote), GFP_KERNEL);
1694 if (!info->notes)
1695 return 0;
1696 info->psinfo = kmalloc(sizeof(*info->psinfo), GFP_KERNEL);
1697 if (!info->psinfo)
1698 goto notes_free;
1699 info->prstatus = kmalloc(sizeof(*info->prstatus), GFP_KERNEL);
1700 if (!info->prstatus)
1701 goto psinfo_free;
1702 info->fpu = kmalloc(sizeof(*info->fpu), GFP_KERNEL);
1703 if (!info->fpu)
1704 goto prstatus_free;
1705 #ifdef ELF_CORE_COPY_XFPREGS
1706 info->xfpu = kmalloc(sizeof(*info->xfpu), GFP_KERNEL);
1707 if (!info->xfpu)
1708 goto fpu_free;
1709 #endif
1710 return 1;
1711 #ifdef ELF_CORE_COPY_XFPREGS
1712 fpu_free:
1713 kfree(info->fpu);
1714 #endif
1715 prstatus_free:
1716 kfree(info->prstatus);
1717 psinfo_free:
1718 kfree(info->psinfo);
1719 notes_free:
1720 kfree(info->notes);
1721 return 0;
1724 static int fill_note_info(struct elfhdr *elf, int phdrs,
1725 struct elf_note_info *info,
1726 long signr, struct pt_regs *regs)
1728 struct list_head *t;
1730 if (!elf_note_info_init(info))
1731 return 0;
1733 if (signr) {
1734 struct core_thread *ct;
1735 struct elf_thread_status *ets;
1737 for (ct = current->mm->core_state->dumper.next;
1738 ct; ct = ct->next) {
1739 ets = kzalloc(sizeof(*ets), GFP_KERNEL);
1740 if (!ets)
1741 return 0;
1743 ets->thread = ct->task;
1744 list_add(&ets->list, &info->thread_list);
1747 list_for_each(t, &info->thread_list) {
1748 int sz;
1750 ets = list_entry(t, struct elf_thread_status, list);
1751 sz = elf_dump_thread_status(signr, ets);
1752 info->thread_status_size += sz;
1755 /* now collect the dump for the current */
1756 memset(info->prstatus, 0, sizeof(*info->prstatus));
1757 fill_prstatus(info->prstatus, current, signr);
1758 elf_core_copy_regs(&info->prstatus->pr_reg, regs);
1760 /* Set up header */
1761 fill_elf_header(elf, phdrs, ELF_ARCH, ELF_CORE_EFLAGS, ELF_OSABI);
1764 * Set up the notes in similar form to SVR4 core dumps made
1765 * with info from their /proc.
1768 fill_note(info->notes + 0, "CORE", NT_PRSTATUS,
1769 sizeof(*info->prstatus), info->prstatus);
1770 fill_psinfo(info->psinfo, current->group_leader, current->mm);
1771 fill_note(info->notes + 1, "CORE", NT_PRPSINFO,
1772 sizeof(*info->psinfo), info->psinfo);
1774 info->numnote = 2;
1776 fill_auxv_note(&info->notes[info->numnote++], current->mm);
1778 /* Try to dump the FPU. */
1779 info->prstatus->pr_fpvalid = elf_core_copy_task_fpregs(current, regs,
1780 info->fpu);
1781 if (info->prstatus->pr_fpvalid)
1782 fill_note(info->notes + info->numnote++,
1783 "CORE", NT_PRFPREG, sizeof(*info->fpu), info->fpu);
1784 #ifdef ELF_CORE_COPY_XFPREGS
1785 if (elf_core_copy_task_xfpregs(current, info->xfpu))
1786 fill_note(info->notes + info->numnote++,
1787 "LINUX", ELF_CORE_XFPREG_TYPE,
1788 sizeof(*info->xfpu), info->xfpu);
1789 #endif
1791 return 1;
1794 static size_t get_note_info_size(struct elf_note_info *info)
1796 int sz = 0;
1797 int i;
1799 for (i = 0; i < info->numnote; i++)
1800 sz += notesize(info->notes + i);
1802 sz += info->thread_status_size;
1804 return sz;
1807 static int write_note_info(struct elf_note_info *info,
1808 struct file *file, loff_t *foffset)
1810 int i;
1811 struct list_head *t;
1813 for (i = 0; i < info->numnote; i++)
1814 if (!writenote(info->notes + i, file, foffset))
1815 return 0;
1817 /* write out the thread status notes section */
1818 list_for_each(t, &info->thread_list) {
1819 struct elf_thread_status *tmp =
1820 list_entry(t, struct elf_thread_status, list);
1822 for (i = 0; i < tmp->num_notes; i++)
1823 if (!writenote(&tmp->notes[i], file, foffset))
1824 return 0;
1827 return 1;
1830 static void free_note_info(struct elf_note_info *info)
1832 while (!list_empty(&info->thread_list)) {
1833 struct list_head *tmp = info->thread_list.next;
1834 list_del(tmp);
1835 kfree(list_entry(tmp, struct elf_thread_status, list));
1838 kfree(info->prstatus);
1839 kfree(info->psinfo);
1840 kfree(info->notes);
1841 kfree(info->fpu);
1842 #ifdef ELF_CORE_COPY_XFPREGS
1843 kfree(info->xfpu);
1844 #endif
1847 #endif
1849 static struct vm_area_struct *first_vma(struct task_struct *tsk,
1850 struct vm_area_struct *gate_vma)
1852 struct vm_area_struct *ret = tsk->mm->mmap;
1854 if (ret)
1855 return ret;
1856 return gate_vma;
1859 * Helper function for iterating across a vma list. It ensures that the caller
1860 * will visit `gate_vma' prior to terminating the search.
1862 static struct vm_area_struct *next_vma(struct vm_area_struct *this_vma,
1863 struct vm_area_struct *gate_vma)
1865 struct vm_area_struct *ret;
1867 ret = this_vma->vm_next;
1868 if (ret)
1869 return ret;
1870 if (this_vma == gate_vma)
1871 return NULL;
1872 return gate_vma;
1876 * Actual dumper
1878 * This is a two-pass process; first we find the offsets of the bits,
1879 * and then they are actually written out. If we run out of core limit
1880 * we just truncate.
1882 static int elf_core_dump(struct coredump_params *cprm)
1884 int has_dumped = 0;
1885 mm_segment_t fs;
1886 int segs;
1887 size_t size = 0;
1888 struct vm_area_struct *vma, *gate_vma;
1889 struct elfhdr *elf = NULL;
1890 loff_t offset = 0, dataoff, foffset;
1891 unsigned long mm_flags;
1892 struct elf_note_info info;
1895 * We no longer stop all VM operations.
1897 * This is because those proceses that could possibly change map_count
1898 * or the mmap / vma pages are now blocked in do_exit on current
1899 * finishing this core dump.
1901 * Only ptrace can touch these memory addresses, but it doesn't change
1902 * the map_count or the pages allocated. So no possibility of crashing
1903 * exists while dumping the mm->vm_next areas to the core file.
1906 /* alloc memory for large data structures: too large to be on stack */
1907 elf = kmalloc(sizeof(*elf), GFP_KERNEL);
1908 if (!elf)
1909 goto out;
1911 * The number of segs are recored into ELF header as 16bit value.
1912 * Please check DEFAULT_MAX_MAP_COUNT definition when you modify here.
1914 segs = current->mm->map_count;
1915 #ifdef ELF_CORE_EXTRA_PHDRS
1916 segs += ELF_CORE_EXTRA_PHDRS;
1917 #endif
1919 gate_vma = get_gate_vma(current);
1920 if (gate_vma != NULL)
1921 segs++;
1924 * Collect all the non-memory information about the process for the
1925 * notes. This also sets up the file header.
1927 if (!fill_note_info(elf, segs + 1, /* including notes section */
1928 &info, cprm->signr, cprm->regs))
1929 goto cleanup;
1931 has_dumped = 1;
1932 current->flags |= PF_DUMPCORE;
1934 fs = get_fs();
1935 set_fs(KERNEL_DS);
1937 DUMP_WRITE(elf, sizeof(*elf));
1938 offset += sizeof(*elf); /* Elf header */
1939 offset += (segs + 1) * sizeof(struct elf_phdr); /* Program headers */
1940 foffset = offset;
1942 /* Write notes phdr entry */
1944 struct elf_phdr phdr;
1945 size_t sz = get_note_info_size(&info);
1947 sz += elf_coredump_extra_notes_size();
1949 fill_elf_note_phdr(&phdr, sz, offset);
1950 offset += sz;
1951 DUMP_WRITE(&phdr, sizeof(phdr));
1954 dataoff = offset = roundup(offset, ELF_EXEC_PAGESIZE);
1957 * We must use the same mm->flags while dumping core to avoid
1958 * inconsistency between the program headers and bodies, otherwise an
1959 * unusable core file can be generated.
1961 mm_flags = current->mm->flags;
1963 /* Write program headers for segments dump */
1964 for (vma = first_vma(current, gate_vma); vma != NULL;
1965 vma = next_vma(vma, gate_vma)) {
1966 struct elf_phdr phdr;
1968 phdr.p_type = PT_LOAD;
1969 phdr.p_offset = offset;
1970 phdr.p_vaddr = vma->vm_start;
1971 phdr.p_paddr = 0;
1972 phdr.p_filesz = vma_dump_size(vma, mm_flags);
1973 phdr.p_memsz = vma->vm_end - vma->vm_start;
1974 offset += phdr.p_filesz;
1975 phdr.p_flags = vma->vm_flags & VM_READ ? PF_R : 0;
1976 if (vma->vm_flags & VM_WRITE)
1977 phdr.p_flags |= PF_W;
1978 if (vma->vm_flags & VM_EXEC)
1979 phdr.p_flags |= PF_X;
1980 phdr.p_align = ELF_EXEC_PAGESIZE;
1982 DUMP_WRITE(&phdr, sizeof(phdr));
1985 #ifdef ELF_CORE_WRITE_EXTRA_PHDRS
1986 ELF_CORE_WRITE_EXTRA_PHDRS;
1987 #endif
1989 /* write out the notes section */
1990 if (!write_note_info(&info, cprm->file, &foffset))
1991 goto end_coredump;
1993 if (elf_coredump_extra_notes_write(cprm->file, &foffset))
1994 goto end_coredump;
1996 /* Align to page */
1997 if (!dump_seek(cprm->file, dataoff - foffset))
1998 goto end_coredump;
2000 for (vma = first_vma(current, gate_vma); vma != NULL;
2001 vma = next_vma(vma, gate_vma)) {
2002 unsigned long addr;
2003 unsigned long end;
2005 end = vma->vm_start + vma_dump_size(vma, mm_flags);
2007 for (addr = vma->vm_start; addr < end; addr += PAGE_SIZE) {
2008 struct page *page;
2009 int stop;
2011 page = get_dump_page(addr);
2012 if (page) {
2013 void *kaddr = kmap(page);
2014 stop = ((size += PAGE_SIZE) > cprm->limit) ||
2015 !dump_write(cprm->file, kaddr,
2016 PAGE_SIZE);
2017 kunmap(page);
2018 page_cache_release(page);
2019 } else
2020 stop = !dump_seek(cprm->file, PAGE_SIZE);
2021 if (stop)
2022 goto end_coredump;
2026 #ifdef ELF_CORE_WRITE_EXTRA_DATA
2027 ELF_CORE_WRITE_EXTRA_DATA;
2028 #endif
2030 end_coredump:
2031 set_fs(fs);
2033 cleanup:
2034 free_note_info(&info);
2035 kfree(elf);
2036 out:
2037 return has_dumped;
2040 #endif /* CONFIG_ELF_CORE */
2042 static int __init init_elf_binfmt(void)
2044 return register_binfmt(&elf_format);
2047 static void __exit exit_elf_binfmt(void)
2049 /* Remove the COFF and ELF loaders. */
2050 unregister_binfmt(&elf_format);
2053 core_initcall(init_elf_binfmt);
2054 module_exit(exit_elf_binfmt);
2055 MODULE_LICENSE("GPL");