swapfile: swap allocation use discard
[linux-2.6/mini2440.git] / fs / binfmt_elf.c
blobc41fa2af76771b16abf72b8acb9e7de4ffa8d851
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/stat.h>
16 #include <linux/time.h>
17 #include <linux/mm.h>
18 #include <linux/mman.h>
19 #include <linux/errno.h>
20 #include <linux/signal.h>
21 #include <linux/binfmts.h>
22 #include <linux/string.h>
23 #include <linux/file.h>
24 #include <linux/fcntl.h>
25 #include <linux/ptrace.h>
26 #include <linux/slab.h>
27 #include <linux/shm.h>
28 #include <linux/personality.h>
29 #include <linux/elfcore.h>
30 #include <linux/init.h>
31 #include <linux/highuid.h>
32 #include <linux/smp.h>
33 #include <linux/compiler.h>
34 #include <linux/highmem.h>
35 #include <linux/pagemap.h>
36 #include <linux/security.h>
37 #include <linux/syscalls.h>
38 #include <linux/random.h>
39 #include <linux/elf.h>
40 #include <linux/utsname.h>
41 #include <asm/uaccess.h>
42 #include <asm/param.h>
43 #include <asm/page.h>
45 static int load_elf_binary(struct linux_binprm *bprm, struct pt_regs *regs);
46 static int load_elf_library(struct file *);
47 static unsigned long elf_map(struct file *, unsigned long, struct elf_phdr *,
48 int, int, unsigned long);
51 * If we don't support core dumping, then supply a NULL so we
52 * don't even try.
54 #if defined(USE_ELF_CORE_DUMP) && defined(CONFIG_ELF_CORE)
55 static int elf_core_dump(long signr, struct pt_regs *regs, struct file *file, unsigned long limit);
56 #else
57 #define elf_core_dump NULL
58 #endif
60 #if ELF_EXEC_PAGESIZE > PAGE_SIZE
61 #define ELF_MIN_ALIGN ELF_EXEC_PAGESIZE
62 #else
63 #define ELF_MIN_ALIGN PAGE_SIZE
64 #endif
66 #ifndef ELF_CORE_EFLAGS
67 #define ELF_CORE_EFLAGS 0
68 #endif
70 #define ELF_PAGESTART(_v) ((_v) & ~(unsigned long)(ELF_MIN_ALIGN-1))
71 #define ELF_PAGEOFFSET(_v) ((_v) & (ELF_MIN_ALIGN-1))
72 #define ELF_PAGEALIGN(_v) (((_v) + ELF_MIN_ALIGN - 1) & ~(ELF_MIN_ALIGN - 1))
74 static struct linux_binfmt elf_format = {
75 .module = THIS_MODULE,
76 .load_binary = load_elf_binary,
77 .load_shlib = load_elf_library,
78 .core_dump = elf_core_dump,
79 .min_coredump = ELF_EXEC_PAGESIZE,
80 .hasvdso = 1
83 #define BAD_ADDR(x) ((unsigned long)(x) >= TASK_SIZE)
85 static int set_brk(unsigned long start, unsigned long end)
87 start = ELF_PAGEALIGN(start);
88 end = ELF_PAGEALIGN(end);
89 if (end > start) {
90 unsigned long addr;
91 down_write(&current->mm->mmap_sem);
92 addr = do_brk(start, end - start);
93 up_write(&current->mm->mmap_sem);
94 if (BAD_ADDR(addr))
95 return addr;
97 current->mm->start_brk = current->mm->brk = end;
98 return 0;
101 /* We need to explicitly zero any fractional pages
102 after the data section (i.e. bss). This would
103 contain the junk from the file that should not
104 be in memory
106 static int padzero(unsigned long elf_bss)
108 unsigned long nbyte;
110 nbyte = ELF_PAGEOFFSET(elf_bss);
111 if (nbyte) {
112 nbyte = ELF_MIN_ALIGN - nbyte;
113 if (clear_user((void __user *) elf_bss, nbyte))
114 return -EFAULT;
116 return 0;
119 /* Let's use some macros to make this stack manipulation a little clearer */
120 #ifdef CONFIG_STACK_GROWSUP
121 #define STACK_ADD(sp, items) ((elf_addr_t __user *)(sp) + (items))
122 #define STACK_ROUND(sp, items) \
123 ((15 + (unsigned long) ((sp) + (items))) &~ 15UL)
124 #define STACK_ALLOC(sp, len) ({ \
125 elf_addr_t __user *old_sp = (elf_addr_t __user *)sp; sp += len; \
126 old_sp; })
127 #else
128 #define STACK_ADD(sp, items) ((elf_addr_t __user *)(sp) - (items))
129 #define STACK_ROUND(sp, items) \
130 (((unsigned long) (sp - items)) &~ 15UL)
131 #define STACK_ALLOC(sp, len) ({ sp -= len ; sp; })
132 #endif
134 #ifndef ELF_BASE_PLATFORM
136 * AT_BASE_PLATFORM indicates the "real" hardware/microarchitecture.
137 * If the arch defines ELF_BASE_PLATFORM (in asm/elf.h), the value
138 * will be copied to the user stack in the same manner as AT_PLATFORM.
140 #define ELF_BASE_PLATFORM NULL
141 #endif
143 static int
144 create_elf_tables(struct linux_binprm *bprm, struct elfhdr *exec,
145 unsigned long load_addr, unsigned long interp_load_addr)
147 unsigned long p = bprm->p;
148 int argc = bprm->argc;
149 int envc = bprm->envc;
150 elf_addr_t __user *argv;
151 elf_addr_t __user *envp;
152 elf_addr_t __user *sp;
153 elf_addr_t __user *u_platform;
154 elf_addr_t __user *u_base_platform;
155 const char *k_platform = ELF_PLATFORM;
156 const char *k_base_platform = ELF_BASE_PLATFORM;
157 int items;
158 elf_addr_t *elf_info;
159 int ei_index = 0;
160 const struct cred *cred = current_cred();
161 struct vm_area_struct *vma;
164 * In some cases (e.g. Hyper-Threading), we want to avoid L1
165 * evictions by the processes running on the same package. One
166 * thing we can do is to shuffle the initial stack for them.
169 p = arch_align_stack(p);
172 * If this architecture has a platform capability string, copy it
173 * to userspace. In some cases (Sparc), this info is impossible
174 * for userspace to get any other way, in others (i386) it is
175 * merely difficult.
177 u_platform = NULL;
178 if (k_platform) {
179 size_t len = strlen(k_platform) + 1;
181 u_platform = (elf_addr_t __user *)STACK_ALLOC(p, len);
182 if (__copy_to_user(u_platform, k_platform, len))
183 return -EFAULT;
187 * If this architecture has a "base" platform capability
188 * string, copy it to userspace.
190 u_base_platform = NULL;
191 if (k_base_platform) {
192 size_t len = strlen(k_base_platform) + 1;
194 u_base_platform = (elf_addr_t __user *)STACK_ALLOC(p, len);
195 if (__copy_to_user(u_base_platform, k_base_platform, len))
196 return -EFAULT;
199 /* Create the ELF interpreter info */
200 elf_info = (elf_addr_t *)current->mm->saved_auxv;
201 /* update AT_VECTOR_SIZE_BASE if the number of NEW_AUX_ENT() changes */
202 #define NEW_AUX_ENT(id, val) \
203 do { \
204 elf_info[ei_index++] = id; \
205 elf_info[ei_index++] = val; \
206 } while (0)
208 #ifdef ARCH_DLINFO
210 * ARCH_DLINFO must come first so PPC can do its special alignment of
211 * AUXV.
212 * update AT_VECTOR_SIZE_ARCH if the number of NEW_AUX_ENT() in
213 * ARCH_DLINFO changes
215 ARCH_DLINFO;
216 #endif
217 NEW_AUX_ENT(AT_HWCAP, ELF_HWCAP);
218 NEW_AUX_ENT(AT_PAGESZ, ELF_EXEC_PAGESIZE);
219 NEW_AUX_ENT(AT_CLKTCK, CLOCKS_PER_SEC);
220 NEW_AUX_ENT(AT_PHDR, load_addr + exec->e_phoff);
221 NEW_AUX_ENT(AT_PHENT, sizeof(struct elf_phdr));
222 NEW_AUX_ENT(AT_PHNUM, exec->e_phnum);
223 NEW_AUX_ENT(AT_BASE, interp_load_addr);
224 NEW_AUX_ENT(AT_FLAGS, 0);
225 NEW_AUX_ENT(AT_ENTRY, exec->e_entry);
226 NEW_AUX_ENT(AT_UID, cred->uid);
227 NEW_AUX_ENT(AT_EUID, cred->euid);
228 NEW_AUX_ENT(AT_GID, cred->gid);
229 NEW_AUX_ENT(AT_EGID, cred->egid);
230 NEW_AUX_ENT(AT_SECURE, security_bprm_secureexec(bprm));
231 NEW_AUX_ENT(AT_EXECFN, bprm->exec);
232 if (k_platform) {
233 NEW_AUX_ENT(AT_PLATFORM,
234 (elf_addr_t)(unsigned long)u_platform);
236 if (k_base_platform) {
237 NEW_AUX_ENT(AT_BASE_PLATFORM,
238 (elf_addr_t)(unsigned long)u_base_platform);
240 if (bprm->interp_flags & BINPRM_FLAGS_EXECFD) {
241 NEW_AUX_ENT(AT_EXECFD, bprm->interp_data);
243 #undef NEW_AUX_ENT
244 /* AT_NULL is zero; clear the rest too */
245 memset(&elf_info[ei_index], 0,
246 sizeof current->mm->saved_auxv - ei_index * sizeof elf_info[0]);
248 /* And advance past the AT_NULL entry. */
249 ei_index += 2;
251 sp = STACK_ADD(p, ei_index);
253 items = (argc + 1) + (envc + 1) + 1;
254 bprm->p = STACK_ROUND(sp, items);
256 /* Point sp at the lowest address on the stack */
257 #ifdef CONFIG_STACK_GROWSUP
258 sp = (elf_addr_t __user *)bprm->p - items - ei_index;
259 bprm->exec = (unsigned long)sp; /* XXX: PARISC HACK */
260 #else
261 sp = (elf_addr_t __user *)bprm->p;
262 #endif
266 * Grow the stack manually; some architectures have a limit on how
267 * far ahead a user-space access may be in order to grow the stack.
269 vma = find_extend_vma(current->mm, bprm->p);
270 if (!vma)
271 return -EFAULT;
273 /* Now, let's put argc (and argv, envp if appropriate) on the stack */
274 if (__put_user(argc, sp++))
275 return -EFAULT;
276 argv = sp;
277 envp = argv + argc + 1;
279 /* Populate argv and envp */
280 p = current->mm->arg_end = current->mm->arg_start;
281 while (argc-- > 0) {
282 size_t len;
283 if (__put_user((elf_addr_t)p, argv++))
284 return -EFAULT;
285 len = strnlen_user((void __user *)p, MAX_ARG_STRLEN);
286 if (!len || len > MAX_ARG_STRLEN)
287 return -EINVAL;
288 p += len;
290 if (__put_user(0, argv))
291 return -EFAULT;
292 current->mm->arg_end = current->mm->env_start = p;
293 while (envc-- > 0) {
294 size_t len;
295 if (__put_user((elf_addr_t)p, envp++))
296 return -EFAULT;
297 len = strnlen_user((void __user *)p, MAX_ARG_STRLEN);
298 if (!len || len > MAX_ARG_STRLEN)
299 return -EINVAL;
300 p += len;
302 if (__put_user(0, envp))
303 return -EFAULT;
304 current->mm->env_end = p;
306 /* Put the elf_info on the stack in the right place. */
307 sp = (elf_addr_t __user *)envp + 1;
308 if (copy_to_user(sp, elf_info, ei_index * sizeof(elf_addr_t)))
309 return -EFAULT;
310 return 0;
313 #ifndef elf_map
315 static unsigned long elf_map(struct file *filep, unsigned long addr,
316 struct elf_phdr *eppnt, int prot, int type,
317 unsigned long total_size)
319 unsigned long map_addr;
320 unsigned long size = eppnt->p_filesz + ELF_PAGEOFFSET(eppnt->p_vaddr);
321 unsigned long off = eppnt->p_offset - ELF_PAGEOFFSET(eppnt->p_vaddr);
322 addr = ELF_PAGESTART(addr);
323 size = ELF_PAGEALIGN(size);
325 /* mmap() will return -EINVAL if given a zero size, but a
326 * segment with zero filesize is perfectly valid */
327 if (!size)
328 return addr;
330 down_write(&current->mm->mmap_sem);
332 * total_size is the size of the ELF (interpreter) image.
333 * The _first_ mmap needs to know the full size, otherwise
334 * randomization might put this image into an overlapping
335 * position with the ELF binary image. (since size < total_size)
336 * So we first map the 'big' image - and unmap the remainder at
337 * the end. (which unmap is needed for ELF images with holes.)
339 if (total_size) {
340 total_size = ELF_PAGEALIGN(total_size);
341 map_addr = do_mmap(filep, addr, total_size, prot, type, off);
342 if (!BAD_ADDR(map_addr))
343 do_munmap(current->mm, map_addr+size, total_size-size);
344 } else
345 map_addr = do_mmap(filep, addr, size, prot, type, off);
347 up_write(&current->mm->mmap_sem);
348 return(map_addr);
351 #endif /* !elf_map */
353 static unsigned long total_mapping_size(struct elf_phdr *cmds, int nr)
355 int i, first_idx = -1, last_idx = -1;
357 for (i = 0; i < nr; i++) {
358 if (cmds[i].p_type == PT_LOAD) {
359 last_idx = i;
360 if (first_idx == -1)
361 first_idx = i;
364 if (first_idx == -1)
365 return 0;
367 return cmds[last_idx].p_vaddr + cmds[last_idx].p_memsz -
368 ELF_PAGESTART(cmds[first_idx].p_vaddr);
372 /* This is much more generalized than the library routine read function,
373 so we keep this separate. Technically the library read function
374 is only provided so that we can read a.out libraries that have
375 an ELF header */
377 static unsigned long load_elf_interp(struct elfhdr *interp_elf_ex,
378 struct file *interpreter, unsigned long *interp_map_addr,
379 unsigned long no_base)
381 struct elf_phdr *elf_phdata;
382 struct elf_phdr *eppnt;
383 unsigned long load_addr = 0;
384 int load_addr_set = 0;
385 unsigned long last_bss = 0, elf_bss = 0;
386 unsigned long error = ~0UL;
387 unsigned long total_size;
388 int retval, i, size;
390 /* First of all, some simple consistency checks */
391 if (interp_elf_ex->e_type != ET_EXEC &&
392 interp_elf_ex->e_type != ET_DYN)
393 goto out;
394 if (!elf_check_arch(interp_elf_ex))
395 goto out;
396 if (!interpreter->f_op || !interpreter->f_op->mmap)
397 goto out;
400 * If the size of this structure has changed, then punt, since
401 * we will be doing the wrong thing.
403 if (interp_elf_ex->e_phentsize != sizeof(struct elf_phdr))
404 goto out;
405 if (interp_elf_ex->e_phnum < 1 ||
406 interp_elf_ex->e_phnum > 65536U / sizeof(struct elf_phdr))
407 goto out;
409 /* Now read in all of the header information */
410 size = sizeof(struct elf_phdr) * interp_elf_ex->e_phnum;
411 if (size > ELF_MIN_ALIGN)
412 goto out;
413 elf_phdata = kmalloc(size, GFP_KERNEL);
414 if (!elf_phdata)
415 goto out;
417 retval = kernel_read(interpreter, interp_elf_ex->e_phoff,
418 (char *)elf_phdata,size);
419 error = -EIO;
420 if (retval != size) {
421 if (retval < 0)
422 error = retval;
423 goto out_close;
426 total_size = total_mapping_size(elf_phdata, interp_elf_ex->e_phnum);
427 if (!total_size) {
428 error = -EINVAL;
429 goto out_close;
432 eppnt = elf_phdata;
433 for (i = 0; i < interp_elf_ex->e_phnum; i++, eppnt++) {
434 if (eppnt->p_type == PT_LOAD) {
435 int elf_type = MAP_PRIVATE | MAP_DENYWRITE;
436 int elf_prot = 0;
437 unsigned long vaddr = 0;
438 unsigned long k, map_addr;
440 if (eppnt->p_flags & PF_R)
441 elf_prot = PROT_READ;
442 if (eppnt->p_flags & PF_W)
443 elf_prot |= PROT_WRITE;
444 if (eppnt->p_flags & PF_X)
445 elf_prot |= PROT_EXEC;
446 vaddr = eppnt->p_vaddr;
447 if (interp_elf_ex->e_type == ET_EXEC || load_addr_set)
448 elf_type |= MAP_FIXED;
449 else if (no_base && interp_elf_ex->e_type == ET_DYN)
450 load_addr = -vaddr;
452 map_addr = elf_map(interpreter, load_addr + vaddr,
453 eppnt, elf_prot, elf_type, total_size);
454 total_size = 0;
455 if (!*interp_map_addr)
456 *interp_map_addr = map_addr;
457 error = map_addr;
458 if (BAD_ADDR(map_addr))
459 goto out_close;
461 if (!load_addr_set &&
462 interp_elf_ex->e_type == ET_DYN) {
463 load_addr = map_addr - ELF_PAGESTART(vaddr);
464 load_addr_set = 1;
468 * Check to see if the section's size will overflow the
469 * allowed task size. Note that p_filesz must always be
470 * <= p_memsize so it's only necessary to check p_memsz.
472 k = load_addr + eppnt->p_vaddr;
473 if (BAD_ADDR(k) ||
474 eppnt->p_filesz > eppnt->p_memsz ||
475 eppnt->p_memsz > TASK_SIZE ||
476 TASK_SIZE - eppnt->p_memsz < k) {
477 error = -ENOMEM;
478 goto out_close;
482 * Find the end of the file mapping for this phdr, and
483 * keep track of the largest address we see for this.
485 k = load_addr + eppnt->p_vaddr + eppnt->p_filesz;
486 if (k > elf_bss)
487 elf_bss = k;
490 * Do the same thing for the memory mapping - between
491 * elf_bss and last_bss is the bss section.
493 k = load_addr + eppnt->p_memsz + eppnt->p_vaddr;
494 if (k > last_bss)
495 last_bss = k;
500 * Now fill out the bss section. First pad the last page up
501 * to the page boundary, and then perform a mmap to make sure
502 * that there are zero-mapped pages up to and including the
503 * last bss page.
505 if (padzero(elf_bss)) {
506 error = -EFAULT;
507 goto out_close;
510 /* What we have mapped so far */
511 elf_bss = ELF_PAGESTART(elf_bss + ELF_MIN_ALIGN - 1);
513 /* Map the last of the bss segment */
514 if (last_bss > elf_bss) {
515 down_write(&current->mm->mmap_sem);
516 error = do_brk(elf_bss, last_bss - elf_bss);
517 up_write(&current->mm->mmap_sem);
518 if (BAD_ADDR(error))
519 goto out_close;
522 error = load_addr;
524 out_close:
525 kfree(elf_phdata);
526 out:
527 return error;
531 * These are the functions used to load ELF style executables and shared
532 * libraries. There is no binary dependent code anywhere else.
535 #define INTERPRETER_NONE 0
536 #define INTERPRETER_ELF 2
538 #ifndef STACK_RND_MASK
539 #define STACK_RND_MASK (0x7ff >> (PAGE_SHIFT - 12)) /* 8MB of VA */
540 #endif
542 static unsigned long randomize_stack_top(unsigned long stack_top)
544 unsigned int random_variable = 0;
546 if ((current->flags & PF_RANDOMIZE) &&
547 !(current->personality & ADDR_NO_RANDOMIZE)) {
548 random_variable = get_random_int() & STACK_RND_MASK;
549 random_variable <<= PAGE_SHIFT;
551 #ifdef CONFIG_STACK_GROWSUP
552 return PAGE_ALIGN(stack_top) + random_variable;
553 #else
554 return PAGE_ALIGN(stack_top) - random_variable;
555 #endif
558 static int load_elf_binary(struct linux_binprm *bprm, struct pt_regs *regs)
560 struct file *interpreter = NULL; /* to shut gcc up */
561 unsigned long load_addr = 0, load_bias = 0;
562 int load_addr_set = 0;
563 char * elf_interpreter = NULL;
564 unsigned long error;
565 struct elf_phdr *elf_ppnt, *elf_phdata;
566 unsigned long elf_bss, elf_brk;
567 int elf_exec_fileno;
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 = 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 retval = get_unused_fd();
623 if (retval < 0)
624 goto out_free_ph;
625 get_file(bprm->file);
626 fd_install(elf_exec_fileno = retval, bprm->file);
628 elf_ppnt = elf_phdata;
629 elf_bss = 0;
630 elf_brk = 0;
632 start_code = ~0UL;
633 end_code = 0;
634 start_data = 0;
635 end_data = 0;
637 for (i = 0; i < loc->elf_ex.e_phnum; i++) {
638 if (elf_ppnt->p_type == PT_INTERP) {
639 /* This is the program interpreter used for
640 * shared libraries - for now assume that this
641 * is an a.out format binary
643 retval = -ENOEXEC;
644 if (elf_ppnt->p_filesz > PATH_MAX ||
645 elf_ppnt->p_filesz < 2)
646 goto out_free_file;
648 retval = -ENOMEM;
649 elf_interpreter = kmalloc(elf_ppnt->p_filesz,
650 GFP_KERNEL);
651 if (!elf_interpreter)
652 goto out_free_file;
654 retval = kernel_read(bprm->file, elf_ppnt->p_offset,
655 elf_interpreter,
656 elf_ppnt->p_filesz);
657 if (retval != elf_ppnt->p_filesz) {
658 if (retval >= 0)
659 retval = -EIO;
660 goto out_free_interp;
662 /* make sure path is NULL terminated */
663 retval = -ENOEXEC;
664 if (elf_interpreter[elf_ppnt->p_filesz - 1] != '\0')
665 goto out_free_interp;
668 * The early SET_PERSONALITY here is so that the lookup
669 * for the interpreter happens in the namespace of the
670 * to-be-execed image. SET_PERSONALITY can select an
671 * alternate root.
673 * However, SET_PERSONALITY is NOT allowed to switch
674 * this task into the new images's memory mapping
675 * policy - that is, TASK_SIZE must still evaluate to
676 * that which is appropriate to the execing application.
677 * This is because exit_mmap() needs to have TASK_SIZE
678 * evaluate to the size of the old image.
680 * So if (say) a 64-bit application is execing a 32-bit
681 * application it is the architecture's responsibility
682 * to defer changing the value of TASK_SIZE until the
683 * switch really is going to happen - do this in
684 * flush_thread(). - akpm
686 SET_PERSONALITY(loc->elf_ex);
688 interpreter = open_exec(elf_interpreter);
689 retval = PTR_ERR(interpreter);
690 if (IS_ERR(interpreter))
691 goto out_free_interp;
694 * If the binary is not readable then enforce
695 * mm->dumpable = 0 regardless of the interpreter's
696 * permissions.
698 if (file_permission(interpreter, MAY_READ) < 0)
699 bprm->interp_flags |= BINPRM_FLAGS_ENFORCE_NONDUMP;
701 retval = kernel_read(interpreter, 0, bprm->buf,
702 BINPRM_BUF_SIZE);
703 if (retval != BINPRM_BUF_SIZE) {
704 if (retval >= 0)
705 retval = -EIO;
706 goto out_free_dentry;
709 /* Get the exec headers */
710 loc->interp_elf_ex = *((struct elfhdr *)bprm->buf);
711 break;
713 elf_ppnt++;
716 elf_ppnt = elf_phdata;
717 for (i = 0; i < loc->elf_ex.e_phnum; i++, elf_ppnt++)
718 if (elf_ppnt->p_type == PT_GNU_STACK) {
719 if (elf_ppnt->p_flags & PF_X)
720 executable_stack = EXSTACK_ENABLE_X;
721 else
722 executable_stack = EXSTACK_DISABLE_X;
723 break;
726 /* Some simple consistency checks for the interpreter */
727 if (elf_interpreter) {
728 retval = -ELIBBAD;
729 /* Not an ELF interpreter */
730 if (memcmp(loc->interp_elf_ex.e_ident, ELFMAG, SELFMAG) != 0)
731 goto out_free_dentry;
732 /* Verify the interpreter has a valid arch */
733 if (!elf_check_arch(&loc->interp_elf_ex))
734 goto out_free_dentry;
735 } else {
736 /* Executables without an interpreter also need a personality */
737 SET_PERSONALITY(loc->elf_ex);
740 /* Flush all traces of the currently running executable */
741 retval = flush_old_exec(bprm);
742 if (retval)
743 goto out_free_dentry;
745 /* OK, This is the point of no return */
746 current->flags &= ~PF_FORKNOEXEC;
747 current->mm->def_flags = def_flags;
749 /* Do this immediately, since STACK_TOP as used in setup_arg_pages
750 may depend on the personality. */
751 SET_PERSONALITY(loc->elf_ex);
752 if (elf_read_implies_exec(loc->elf_ex, executable_stack))
753 current->personality |= READ_IMPLIES_EXEC;
755 if (!(current->personality & ADDR_NO_RANDOMIZE) && randomize_va_space)
756 current->flags |= PF_RANDOMIZE;
757 arch_pick_mmap_layout(current->mm);
759 /* Do this so that we can load the interpreter, if need be. We will
760 change some of these later */
761 current->mm->free_area_cache = current->mm->mmap_base;
762 current->mm->cached_hole_size = 0;
763 retval = setup_arg_pages(bprm, randomize_stack_top(STACK_TOP),
764 executable_stack);
765 if (retval < 0) {
766 send_sig(SIGKILL, current, 0);
767 goto out_free_dentry;
770 current->mm->start_stack = bprm->p;
772 /* Now we do a little grungy work by mmaping the ELF image into
773 the correct location in memory. */
774 for(i = 0, elf_ppnt = elf_phdata;
775 i < loc->elf_ex.e_phnum; i++, elf_ppnt++) {
776 int elf_prot = 0, elf_flags;
777 unsigned long k, vaddr;
779 if (elf_ppnt->p_type != PT_LOAD)
780 continue;
782 if (unlikely (elf_brk > elf_bss)) {
783 unsigned long nbyte;
785 /* There was a PT_LOAD segment with p_memsz > p_filesz
786 before this one. Map anonymous pages, if needed,
787 and clear the area. */
788 retval = set_brk (elf_bss + load_bias,
789 elf_brk + load_bias);
790 if (retval) {
791 send_sig(SIGKILL, current, 0);
792 goto out_free_dentry;
794 nbyte = ELF_PAGEOFFSET(elf_bss);
795 if (nbyte) {
796 nbyte = ELF_MIN_ALIGN - nbyte;
797 if (nbyte > elf_brk - elf_bss)
798 nbyte = elf_brk - elf_bss;
799 if (clear_user((void __user *)elf_bss +
800 load_bias, nbyte)) {
802 * This bss-zeroing can fail if the ELF
803 * file specifies odd protections. So
804 * we don't check the return value
810 if (elf_ppnt->p_flags & PF_R)
811 elf_prot |= PROT_READ;
812 if (elf_ppnt->p_flags & PF_W)
813 elf_prot |= PROT_WRITE;
814 if (elf_ppnt->p_flags & PF_X)
815 elf_prot |= PROT_EXEC;
817 elf_flags = MAP_PRIVATE | MAP_DENYWRITE | MAP_EXECUTABLE;
819 vaddr = elf_ppnt->p_vaddr;
820 if (loc->elf_ex.e_type == ET_EXEC || load_addr_set) {
821 elf_flags |= MAP_FIXED;
822 } else if (loc->elf_ex.e_type == ET_DYN) {
823 /* Try and get dynamic programs out of the way of the
824 * default mmap base, as well as whatever program they
825 * might try to exec. This is because the brk will
826 * follow the loader, and is not movable. */
827 #ifdef CONFIG_X86
828 load_bias = 0;
829 #else
830 load_bias = ELF_PAGESTART(ELF_ET_DYN_BASE - vaddr);
831 #endif
834 error = elf_map(bprm->file, load_bias + vaddr, elf_ppnt,
835 elf_prot, elf_flags, 0);
836 if (BAD_ADDR(error)) {
837 send_sig(SIGKILL, current, 0);
838 retval = IS_ERR((void *)error) ?
839 PTR_ERR((void*)error) : -EINVAL;
840 goto out_free_dentry;
843 if (!load_addr_set) {
844 load_addr_set = 1;
845 load_addr = (elf_ppnt->p_vaddr - elf_ppnt->p_offset);
846 if (loc->elf_ex.e_type == ET_DYN) {
847 load_bias += error -
848 ELF_PAGESTART(load_bias + vaddr);
849 load_addr += load_bias;
850 reloc_func_desc = load_bias;
853 k = elf_ppnt->p_vaddr;
854 if (k < start_code)
855 start_code = k;
856 if (start_data < k)
857 start_data = k;
860 * Check to see if the section's size will overflow the
861 * allowed task size. Note that p_filesz must always be
862 * <= p_memsz so it is only necessary to check p_memsz.
864 if (BAD_ADDR(k) || elf_ppnt->p_filesz > elf_ppnt->p_memsz ||
865 elf_ppnt->p_memsz > TASK_SIZE ||
866 TASK_SIZE - elf_ppnt->p_memsz < k) {
867 /* set_brk can never work. Avoid overflows. */
868 send_sig(SIGKILL, current, 0);
869 retval = -EINVAL;
870 goto out_free_dentry;
873 k = elf_ppnt->p_vaddr + elf_ppnt->p_filesz;
875 if (k > elf_bss)
876 elf_bss = k;
877 if ((elf_ppnt->p_flags & PF_X) && end_code < k)
878 end_code = k;
879 if (end_data < k)
880 end_data = k;
881 k = elf_ppnt->p_vaddr + elf_ppnt->p_memsz;
882 if (k > elf_brk)
883 elf_brk = k;
886 loc->elf_ex.e_entry += load_bias;
887 elf_bss += load_bias;
888 elf_brk += load_bias;
889 start_code += load_bias;
890 end_code += load_bias;
891 start_data += load_bias;
892 end_data += load_bias;
894 /* Calling set_brk effectively mmaps the pages that we need
895 * for the bss and break sections. We must do this before
896 * mapping in the interpreter, to make sure it doesn't wind
897 * up getting placed where the bss needs to go.
899 retval = set_brk(elf_bss, elf_brk);
900 if (retval) {
901 send_sig(SIGKILL, current, 0);
902 goto out_free_dentry;
904 if (likely(elf_bss != elf_brk) && unlikely(padzero(elf_bss))) {
905 send_sig(SIGSEGV, current, 0);
906 retval = -EFAULT; /* Nobody gets to see this, but.. */
907 goto out_free_dentry;
910 if (elf_interpreter) {
911 unsigned long uninitialized_var(interp_map_addr);
913 elf_entry = load_elf_interp(&loc->interp_elf_ex,
914 interpreter,
915 &interp_map_addr,
916 load_bias);
917 if (!IS_ERR((void *)elf_entry)) {
919 * load_elf_interp() returns relocation
920 * adjustment
922 interp_load_addr = elf_entry;
923 elf_entry += loc->interp_elf_ex.e_entry;
925 if (BAD_ADDR(elf_entry)) {
926 force_sig(SIGSEGV, current);
927 retval = IS_ERR((void *)elf_entry) ?
928 (int)elf_entry : -EINVAL;
929 goto out_free_dentry;
931 reloc_func_desc = interp_load_addr;
933 allow_write_access(interpreter);
934 fput(interpreter);
935 kfree(elf_interpreter);
936 } else {
937 elf_entry = loc->elf_ex.e_entry;
938 if (BAD_ADDR(elf_entry)) {
939 force_sig(SIGSEGV, current);
940 retval = -EINVAL;
941 goto out_free_dentry;
945 kfree(elf_phdata);
947 sys_close(elf_exec_fileno);
949 set_binfmt(&elf_format);
951 #ifdef ARCH_HAS_SETUP_ADDITIONAL_PAGES
952 retval = arch_setup_additional_pages(bprm, !!elf_interpreter);
953 if (retval < 0) {
954 send_sig(SIGKILL, current, 0);
955 goto out;
957 #endif /* ARCH_HAS_SETUP_ADDITIONAL_PAGES */
959 install_exec_creds(bprm);
960 current->flags &= ~PF_FORKNOEXEC;
961 retval = create_elf_tables(bprm, &loc->elf_ex,
962 load_addr, interp_load_addr);
963 if (retval < 0) {
964 send_sig(SIGKILL, current, 0);
965 goto out;
967 /* N.B. passed_fileno might not be initialized? */
968 current->mm->end_code = end_code;
969 current->mm->start_code = start_code;
970 current->mm->start_data = start_data;
971 current->mm->end_data = end_data;
972 current->mm->start_stack = bprm->p;
974 #ifdef arch_randomize_brk
975 if ((current->flags & PF_RANDOMIZE) && (randomize_va_space > 1))
976 current->mm->brk = current->mm->start_brk =
977 arch_randomize_brk(current->mm);
978 #endif
980 if (current->personality & MMAP_PAGE_ZERO) {
981 /* Why this, you ask??? Well SVr4 maps page 0 as read-only,
982 and some applications "depend" upon this behavior.
983 Since we do not have the power to recompile these, we
984 emulate the SVr4 behavior. Sigh. */
985 down_write(&current->mm->mmap_sem);
986 error = do_mmap(NULL, 0, PAGE_SIZE, PROT_READ | PROT_EXEC,
987 MAP_FIXED | MAP_PRIVATE, 0);
988 up_write(&current->mm->mmap_sem);
991 #ifdef ELF_PLAT_INIT
993 * The ABI may specify that certain registers be set up in special
994 * ways (on i386 %edx is the address of a DT_FINI function, for
995 * example. In addition, it may also specify (eg, PowerPC64 ELF)
996 * that the e_entry field is the address of the function descriptor
997 * for the startup routine, rather than the address of the startup
998 * routine itself. This macro performs whatever initialization to
999 * the regs structure is required as well as any relocations to the
1000 * function descriptor entries when executing dynamically links apps.
1002 ELF_PLAT_INIT(regs, reloc_func_desc);
1003 #endif
1005 start_thread(regs, elf_entry, bprm->p);
1006 retval = 0;
1007 out:
1008 kfree(loc);
1009 out_ret:
1010 return retval;
1012 /* error cleanup */
1013 out_free_dentry:
1014 allow_write_access(interpreter);
1015 if (interpreter)
1016 fput(interpreter);
1017 out_free_interp:
1018 kfree(elf_interpreter);
1019 out_free_file:
1020 sys_close(elf_exec_fileno);
1021 out_free_ph:
1022 kfree(elf_phdata);
1023 goto out;
1026 /* This is really simpleminded and specialized - we are loading an
1027 a.out library that is given an ELF header. */
1028 static int load_elf_library(struct file *file)
1030 struct elf_phdr *elf_phdata;
1031 struct elf_phdr *eppnt;
1032 unsigned long elf_bss, bss, len;
1033 int retval, error, i, j;
1034 struct elfhdr elf_ex;
1036 error = -ENOEXEC;
1037 retval = kernel_read(file, 0, (char *)&elf_ex, sizeof(elf_ex));
1038 if (retval != sizeof(elf_ex))
1039 goto out;
1041 if (memcmp(elf_ex.e_ident, ELFMAG, SELFMAG) != 0)
1042 goto out;
1044 /* First of all, some simple consistency checks */
1045 if (elf_ex.e_type != ET_EXEC || elf_ex.e_phnum > 2 ||
1046 !elf_check_arch(&elf_ex) || !file->f_op || !file->f_op->mmap)
1047 goto out;
1049 /* Now read in all of the header information */
1051 j = sizeof(struct elf_phdr) * elf_ex.e_phnum;
1052 /* j < ELF_MIN_ALIGN because elf_ex.e_phnum <= 2 */
1054 error = -ENOMEM;
1055 elf_phdata = kmalloc(j, GFP_KERNEL);
1056 if (!elf_phdata)
1057 goto out;
1059 eppnt = elf_phdata;
1060 error = -ENOEXEC;
1061 retval = kernel_read(file, elf_ex.e_phoff, (char *)eppnt, j);
1062 if (retval != j)
1063 goto out_free_ph;
1065 for (j = 0, i = 0; i<elf_ex.e_phnum; i++)
1066 if ((eppnt + i)->p_type == PT_LOAD)
1067 j++;
1068 if (j != 1)
1069 goto out_free_ph;
1071 while (eppnt->p_type != PT_LOAD)
1072 eppnt++;
1074 /* Now use mmap to map the library into memory. */
1075 down_write(&current->mm->mmap_sem);
1076 error = do_mmap(file,
1077 ELF_PAGESTART(eppnt->p_vaddr),
1078 (eppnt->p_filesz +
1079 ELF_PAGEOFFSET(eppnt->p_vaddr)),
1080 PROT_READ | PROT_WRITE | PROT_EXEC,
1081 MAP_FIXED | MAP_PRIVATE | MAP_DENYWRITE,
1082 (eppnt->p_offset -
1083 ELF_PAGEOFFSET(eppnt->p_vaddr)));
1084 up_write(&current->mm->mmap_sem);
1085 if (error != ELF_PAGESTART(eppnt->p_vaddr))
1086 goto out_free_ph;
1088 elf_bss = eppnt->p_vaddr + eppnt->p_filesz;
1089 if (padzero(elf_bss)) {
1090 error = -EFAULT;
1091 goto out_free_ph;
1094 len = ELF_PAGESTART(eppnt->p_filesz + eppnt->p_vaddr +
1095 ELF_MIN_ALIGN - 1);
1096 bss = eppnt->p_memsz + eppnt->p_vaddr;
1097 if (bss > len) {
1098 down_write(&current->mm->mmap_sem);
1099 do_brk(len, bss - len);
1100 up_write(&current->mm->mmap_sem);
1102 error = 0;
1104 out_free_ph:
1105 kfree(elf_phdata);
1106 out:
1107 return error;
1111 * Note that some platforms still use traditional core dumps and not
1112 * the ELF core dump. Each platform can select it as appropriate.
1114 #if defined(USE_ELF_CORE_DUMP) && defined(CONFIG_ELF_CORE)
1117 * ELF core dumper
1119 * Modelled on fs/exec.c:aout_core_dump()
1120 * Jeremy Fitzhardinge <jeremy@sw.oz.au>
1123 * These are the only things you should do on a core-file: use only these
1124 * functions to write out all the necessary info.
1126 static int dump_write(struct file *file, const void *addr, int nr)
1128 return file->f_op->write(file, addr, nr, &file->f_pos) == nr;
1131 static int dump_seek(struct file *file, loff_t off)
1133 if (file->f_op->llseek && file->f_op->llseek != no_llseek) {
1134 if (file->f_op->llseek(file, off, SEEK_CUR) < 0)
1135 return 0;
1136 } else {
1137 char *buf = (char *)get_zeroed_page(GFP_KERNEL);
1138 if (!buf)
1139 return 0;
1140 while (off > 0) {
1141 unsigned long n = off;
1142 if (n > PAGE_SIZE)
1143 n = PAGE_SIZE;
1144 if (!dump_write(file, buf, n))
1145 return 0;
1146 off -= n;
1148 free_page((unsigned long)buf);
1150 return 1;
1154 * Decide what to dump of a segment, part, all or none.
1156 static unsigned long vma_dump_size(struct vm_area_struct *vma,
1157 unsigned long mm_flags)
1159 #define FILTER(type) (mm_flags & (1UL << MMF_DUMP_##type))
1161 /* The vma can be set up to tell us the answer directly. */
1162 if (vma->vm_flags & VM_ALWAYSDUMP)
1163 goto whole;
1165 /* Hugetlb memory check */
1166 if (vma->vm_flags & VM_HUGETLB) {
1167 if ((vma->vm_flags & VM_SHARED) && FILTER(HUGETLB_SHARED))
1168 goto whole;
1169 if (!(vma->vm_flags & VM_SHARED) && FILTER(HUGETLB_PRIVATE))
1170 goto whole;
1173 /* Do not dump I/O mapped devices or special mappings */
1174 if (vma->vm_flags & (VM_IO | VM_RESERVED))
1175 return 0;
1177 /* By default, dump shared memory if mapped from an anonymous file. */
1178 if (vma->vm_flags & VM_SHARED) {
1179 if (vma->vm_file->f_path.dentry->d_inode->i_nlink == 0 ?
1180 FILTER(ANON_SHARED) : FILTER(MAPPED_SHARED))
1181 goto whole;
1182 return 0;
1185 /* Dump segments that have been written to. */
1186 if (vma->anon_vma && FILTER(ANON_PRIVATE))
1187 goto whole;
1188 if (vma->vm_file == NULL)
1189 return 0;
1191 if (FILTER(MAPPED_PRIVATE))
1192 goto whole;
1195 * If this looks like the beginning of a DSO or executable mapping,
1196 * check for an ELF header. If we find one, dump the first page to
1197 * aid in determining what was mapped here.
1199 if (FILTER(ELF_HEADERS) && vma->vm_file != NULL && vma->vm_pgoff == 0) {
1200 u32 __user *header = (u32 __user *) vma->vm_start;
1201 u32 word;
1203 * Doing it this way gets the constant folded by GCC.
1205 union {
1206 u32 cmp;
1207 char elfmag[SELFMAG];
1208 } magic;
1209 BUILD_BUG_ON(SELFMAG != sizeof word);
1210 magic.elfmag[EI_MAG0] = ELFMAG0;
1211 magic.elfmag[EI_MAG1] = ELFMAG1;
1212 magic.elfmag[EI_MAG2] = ELFMAG2;
1213 magic.elfmag[EI_MAG3] = ELFMAG3;
1214 if (get_user(word, header) == 0 && word == magic.cmp)
1215 return PAGE_SIZE;
1218 #undef FILTER
1220 return 0;
1222 whole:
1223 return vma->vm_end - vma->vm_start;
1226 /* An ELF note in memory */
1227 struct memelfnote
1229 const char *name;
1230 int type;
1231 unsigned int datasz;
1232 void *data;
1235 static int notesize(struct memelfnote *en)
1237 int sz;
1239 sz = sizeof(struct elf_note);
1240 sz += roundup(strlen(en->name) + 1, 4);
1241 sz += roundup(en->datasz, 4);
1243 return sz;
1246 #define DUMP_WRITE(addr, nr, foffset) \
1247 do { if (!dump_write(file, (addr), (nr))) return 0; *foffset += (nr); } while(0)
1249 static int alignfile(struct file *file, loff_t *foffset)
1251 static const char buf[4] = { 0, };
1252 DUMP_WRITE(buf, roundup(*foffset, 4) - *foffset, foffset);
1253 return 1;
1256 static int writenote(struct memelfnote *men, struct file *file,
1257 loff_t *foffset)
1259 struct elf_note en;
1260 en.n_namesz = strlen(men->name) + 1;
1261 en.n_descsz = men->datasz;
1262 en.n_type = men->type;
1264 DUMP_WRITE(&en, sizeof(en), foffset);
1265 DUMP_WRITE(men->name, en.n_namesz, foffset);
1266 if (!alignfile(file, foffset))
1267 return 0;
1268 DUMP_WRITE(men->data, men->datasz, foffset);
1269 if (!alignfile(file, foffset))
1270 return 0;
1272 return 1;
1274 #undef DUMP_WRITE
1276 #define DUMP_WRITE(addr, nr) \
1277 if ((size += (nr)) > limit || !dump_write(file, (addr), (nr))) \
1278 goto end_coredump;
1279 #define DUMP_SEEK(off) \
1280 if (!dump_seek(file, (off))) \
1281 goto end_coredump;
1283 static void fill_elf_header(struct elfhdr *elf, int segs,
1284 u16 machine, u32 flags, u8 osabi)
1286 memset(elf, 0, sizeof(*elf));
1288 memcpy(elf->e_ident, ELFMAG, SELFMAG);
1289 elf->e_ident[EI_CLASS] = ELF_CLASS;
1290 elf->e_ident[EI_DATA] = ELF_DATA;
1291 elf->e_ident[EI_VERSION] = EV_CURRENT;
1292 elf->e_ident[EI_OSABI] = ELF_OSABI;
1294 elf->e_type = ET_CORE;
1295 elf->e_machine = machine;
1296 elf->e_version = EV_CURRENT;
1297 elf->e_phoff = sizeof(struct elfhdr);
1298 elf->e_flags = flags;
1299 elf->e_ehsize = sizeof(struct elfhdr);
1300 elf->e_phentsize = sizeof(struct elf_phdr);
1301 elf->e_phnum = segs;
1303 return;
1306 static void fill_elf_note_phdr(struct elf_phdr *phdr, int sz, loff_t offset)
1308 phdr->p_type = PT_NOTE;
1309 phdr->p_offset = offset;
1310 phdr->p_vaddr = 0;
1311 phdr->p_paddr = 0;
1312 phdr->p_filesz = sz;
1313 phdr->p_memsz = 0;
1314 phdr->p_flags = 0;
1315 phdr->p_align = 0;
1316 return;
1319 static void fill_note(struct memelfnote *note, const char *name, int type,
1320 unsigned int sz, void *data)
1322 note->name = name;
1323 note->type = type;
1324 note->datasz = sz;
1325 note->data = data;
1326 return;
1330 * fill up all the fields in prstatus from the given task struct, except
1331 * registers which need to be filled up separately.
1333 static void fill_prstatus(struct elf_prstatus *prstatus,
1334 struct task_struct *p, long signr)
1336 prstatus->pr_info.si_signo = prstatus->pr_cursig = signr;
1337 prstatus->pr_sigpend = p->pending.signal.sig[0];
1338 prstatus->pr_sighold = p->blocked.sig[0];
1339 prstatus->pr_pid = task_pid_vnr(p);
1340 prstatus->pr_ppid = task_pid_vnr(p->real_parent);
1341 prstatus->pr_pgrp = task_pgrp_vnr(p);
1342 prstatus->pr_sid = task_session_vnr(p);
1343 if (thread_group_leader(p)) {
1344 struct task_cputime cputime;
1347 * This is the record for the group leader. It shows the
1348 * group-wide total, not its individual thread total.
1350 thread_group_cputime(p, &cputime);
1351 cputime_to_timeval(cputime.utime, &prstatus->pr_utime);
1352 cputime_to_timeval(cputime.stime, &prstatus->pr_stime);
1353 } else {
1354 cputime_to_timeval(p->utime, &prstatus->pr_utime);
1355 cputime_to_timeval(p->stime, &prstatus->pr_stime);
1357 cputime_to_timeval(p->signal->cutime, &prstatus->pr_cutime);
1358 cputime_to_timeval(p->signal->cstime, &prstatus->pr_cstime);
1361 static int fill_psinfo(struct elf_prpsinfo *psinfo, struct task_struct *p,
1362 struct mm_struct *mm)
1364 const struct cred *cred;
1365 unsigned int i, len;
1367 /* first copy the parameters from user space */
1368 memset(psinfo, 0, sizeof(struct elf_prpsinfo));
1370 len = mm->arg_end - mm->arg_start;
1371 if (len >= ELF_PRARGSZ)
1372 len = ELF_PRARGSZ-1;
1373 if (copy_from_user(&psinfo->pr_psargs,
1374 (const char __user *)mm->arg_start, len))
1375 return -EFAULT;
1376 for(i = 0; i < len; i++)
1377 if (psinfo->pr_psargs[i] == 0)
1378 psinfo->pr_psargs[i] = ' ';
1379 psinfo->pr_psargs[len] = 0;
1381 psinfo->pr_pid = task_pid_vnr(p);
1382 psinfo->pr_ppid = task_pid_vnr(p->real_parent);
1383 psinfo->pr_pgrp = task_pgrp_vnr(p);
1384 psinfo->pr_sid = task_session_vnr(p);
1386 i = p->state ? ffz(~p->state) + 1 : 0;
1387 psinfo->pr_state = i;
1388 psinfo->pr_sname = (i > 5) ? '.' : "RSDTZW"[i];
1389 psinfo->pr_zomb = psinfo->pr_sname == 'Z';
1390 psinfo->pr_nice = task_nice(p);
1391 psinfo->pr_flag = p->flags;
1392 rcu_read_lock();
1393 cred = __task_cred(p);
1394 SET_UID(psinfo->pr_uid, cred->uid);
1395 SET_GID(psinfo->pr_gid, cred->gid);
1396 rcu_read_unlock();
1397 strncpy(psinfo->pr_fname, p->comm, sizeof(psinfo->pr_fname));
1399 return 0;
1402 static void fill_auxv_note(struct memelfnote *note, struct mm_struct *mm)
1404 elf_addr_t *auxv = (elf_addr_t *) mm->saved_auxv;
1405 int i = 0;
1407 i += 2;
1408 while (auxv[i - 2] != AT_NULL);
1409 fill_note(note, "CORE", NT_AUXV, i * sizeof(elf_addr_t), auxv);
1412 #ifdef CORE_DUMP_USE_REGSET
1413 #include <linux/regset.h>
1415 struct elf_thread_core_info {
1416 struct elf_thread_core_info *next;
1417 struct task_struct *task;
1418 struct elf_prstatus prstatus;
1419 struct memelfnote notes[0];
1422 struct elf_note_info {
1423 struct elf_thread_core_info *thread;
1424 struct memelfnote psinfo;
1425 struct memelfnote auxv;
1426 size_t size;
1427 int thread_notes;
1431 * When a regset has a writeback hook, we call it on each thread before
1432 * dumping user memory. On register window machines, this makes sure the
1433 * user memory backing the register data is up to date before we read it.
1435 static void do_thread_regset_writeback(struct task_struct *task,
1436 const struct user_regset *regset)
1438 if (regset->writeback)
1439 regset->writeback(task, regset, 1);
1442 static int fill_thread_core_info(struct elf_thread_core_info *t,
1443 const struct user_regset_view *view,
1444 long signr, size_t *total)
1446 unsigned int i;
1449 * NT_PRSTATUS is the one special case, because the regset data
1450 * goes into the pr_reg field inside the note contents, rather
1451 * than being the whole note contents. We fill the reset in here.
1452 * We assume that regset 0 is NT_PRSTATUS.
1454 fill_prstatus(&t->prstatus, t->task, signr);
1455 (void) view->regsets[0].get(t->task, &view->regsets[0],
1456 0, sizeof(t->prstatus.pr_reg),
1457 &t->prstatus.pr_reg, NULL);
1459 fill_note(&t->notes[0], "CORE", NT_PRSTATUS,
1460 sizeof(t->prstatus), &t->prstatus);
1461 *total += notesize(&t->notes[0]);
1463 do_thread_regset_writeback(t->task, &view->regsets[0]);
1466 * Each other regset might generate a note too. For each regset
1467 * that has no core_note_type or is inactive, we leave t->notes[i]
1468 * all zero and we'll know to skip writing it later.
1470 for (i = 1; i < view->n; ++i) {
1471 const struct user_regset *regset = &view->regsets[i];
1472 do_thread_regset_writeback(t->task, regset);
1473 if (regset->core_note_type &&
1474 (!regset->active || regset->active(t->task, regset))) {
1475 int ret;
1476 size_t size = regset->n * regset->size;
1477 void *data = kmalloc(size, GFP_KERNEL);
1478 if (unlikely(!data))
1479 return 0;
1480 ret = regset->get(t->task, regset,
1481 0, size, data, NULL);
1482 if (unlikely(ret))
1483 kfree(data);
1484 else {
1485 if (regset->core_note_type != NT_PRFPREG)
1486 fill_note(&t->notes[i], "LINUX",
1487 regset->core_note_type,
1488 size, data);
1489 else {
1490 t->prstatus.pr_fpvalid = 1;
1491 fill_note(&t->notes[i], "CORE",
1492 NT_PRFPREG, size, data);
1494 *total += notesize(&t->notes[i]);
1499 return 1;
1502 static int fill_note_info(struct elfhdr *elf, int phdrs,
1503 struct elf_note_info *info,
1504 long signr, struct pt_regs *regs)
1506 struct task_struct *dump_task = current;
1507 const struct user_regset_view *view = task_user_regset_view(dump_task);
1508 struct elf_thread_core_info *t;
1509 struct elf_prpsinfo *psinfo;
1510 struct core_thread *ct;
1511 unsigned int i;
1513 info->size = 0;
1514 info->thread = NULL;
1516 psinfo = kmalloc(sizeof(*psinfo), GFP_KERNEL);
1517 fill_note(&info->psinfo, "CORE", NT_PRPSINFO, sizeof(*psinfo), psinfo);
1519 if (psinfo == NULL)
1520 return 0;
1523 * Figure out how many notes we're going to need for each thread.
1525 info->thread_notes = 0;
1526 for (i = 0; i < view->n; ++i)
1527 if (view->regsets[i].core_note_type != 0)
1528 ++info->thread_notes;
1531 * Sanity check. We rely on regset 0 being in NT_PRSTATUS,
1532 * since it is our one special case.
1534 if (unlikely(info->thread_notes == 0) ||
1535 unlikely(view->regsets[0].core_note_type != NT_PRSTATUS)) {
1536 WARN_ON(1);
1537 return 0;
1541 * Initialize the ELF file header.
1543 fill_elf_header(elf, phdrs,
1544 view->e_machine, view->e_flags, view->ei_osabi);
1547 * Allocate a structure for each thread.
1549 for (ct = &dump_task->mm->core_state->dumper; ct; ct = ct->next) {
1550 t = kzalloc(offsetof(struct elf_thread_core_info,
1551 notes[info->thread_notes]),
1552 GFP_KERNEL);
1553 if (unlikely(!t))
1554 return 0;
1556 t->task = ct->task;
1557 if (ct->task == dump_task || !info->thread) {
1558 t->next = info->thread;
1559 info->thread = t;
1560 } else {
1562 * Make sure to keep the original task at
1563 * the head of the list.
1565 t->next = info->thread->next;
1566 info->thread->next = t;
1571 * Now fill in each thread's information.
1573 for (t = info->thread; t != NULL; t = t->next)
1574 if (!fill_thread_core_info(t, view, signr, &info->size))
1575 return 0;
1578 * Fill in the two process-wide notes.
1580 fill_psinfo(psinfo, dump_task->group_leader, dump_task->mm);
1581 info->size += notesize(&info->psinfo);
1583 fill_auxv_note(&info->auxv, current->mm);
1584 info->size += notesize(&info->auxv);
1586 return 1;
1589 static size_t get_note_info_size(struct elf_note_info *info)
1591 return info->size;
1595 * Write all the notes for each thread. When writing the first thread, the
1596 * process-wide notes are interleaved after the first thread-specific note.
1598 static int write_note_info(struct elf_note_info *info,
1599 struct file *file, loff_t *foffset)
1601 bool first = 1;
1602 struct elf_thread_core_info *t = info->thread;
1604 do {
1605 int i;
1607 if (!writenote(&t->notes[0], file, foffset))
1608 return 0;
1610 if (first && !writenote(&info->psinfo, file, foffset))
1611 return 0;
1612 if (first && !writenote(&info->auxv, file, foffset))
1613 return 0;
1615 for (i = 1; i < info->thread_notes; ++i)
1616 if (t->notes[i].data &&
1617 !writenote(&t->notes[i], file, foffset))
1618 return 0;
1620 first = 0;
1621 t = t->next;
1622 } while (t);
1624 return 1;
1627 static void free_note_info(struct elf_note_info *info)
1629 struct elf_thread_core_info *threads = info->thread;
1630 while (threads) {
1631 unsigned int i;
1632 struct elf_thread_core_info *t = threads;
1633 threads = t->next;
1634 WARN_ON(t->notes[0].data && t->notes[0].data != &t->prstatus);
1635 for (i = 1; i < info->thread_notes; ++i)
1636 kfree(t->notes[i].data);
1637 kfree(t);
1639 kfree(info->psinfo.data);
1642 #else
1644 /* Here is the structure in which status of each thread is captured. */
1645 struct elf_thread_status
1647 struct list_head list;
1648 struct elf_prstatus prstatus; /* NT_PRSTATUS */
1649 elf_fpregset_t fpu; /* NT_PRFPREG */
1650 struct task_struct *thread;
1651 #ifdef ELF_CORE_COPY_XFPREGS
1652 elf_fpxregset_t xfpu; /* ELF_CORE_XFPREG_TYPE */
1653 #endif
1654 struct memelfnote notes[3];
1655 int num_notes;
1659 * In order to add the specific thread information for the elf file format,
1660 * we need to keep a linked list of every threads pr_status and then create
1661 * a single section for them in the final core file.
1663 static int elf_dump_thread_status(long signr, struct elf_thread_status *t)
1665 int sz = 0;
1666 struct task_struct *p = t->thread;
1667 t->num_notes = 0;
1669 fill_prstatus(&t->prstatus, p, signr);
1670 elf_core_copy_task_regs(p, &t->prstatus.pr_reg);
1672 fill_note(&t->notes[0], "CORE", NT_PRSTATUS, sizeof(t->prstatus),
1673 &(t->prstatus));
1674 t->num_notes++;
1675 sz += notesize(&t->notes[0]);
1677 if ((t->prstatus.pr_fpvalid = elf_core_copy_task_fpregs(p, NULL,
1678 &t->fpu))) {
1679 fill_note(&t->notes[1], "CORE", NT_PRFPREG, sizeof(t->fpu),
1680 &(t->fpu));
1681 t->num_notes++;
1682 sz += notesize(&t->notes[1]);
1685 #ifdef ELF_CORE_COPY_XFPREGS
1686 if (elf_core_copy_task_xfpregs(p, &t->xfpu)) {
1687 fill_note(&t->notes[2], "LINUX", ELF_CORE_XFPREG_TYPE,
1688 sizeof(t->xfpu), &t->xfpu);
1689 t->num_notes++;
1690 sz += notesize(&t->notes[2]);
1692 #endif
1693 return sz;
1696 struct elf_note_info {
1697 struct memelfnote *notes;
1698 struct elf_prstatus *prstatus; /* NT_PRSTATUS */
1699 struct elf_prpsinfo *psinfo; /* NT_PRPSINFO */
1700 struct list_head thread_list;
1701 elf_fpregset_t *fpu;
1702 #ifdef ELF_CORE_COPY_XFPREGS
1703 elf_fpxregset_t *xfpu;
1704 #endif
1705 int thread_status_size;
1706 int numnote;
1709 static int fill_note_info(struct elfhdr *elf, int phdrs,
1710 struct elf_note_info *info,
1711 long signr, struct pt_regs *regs)
1713 #define NUM_NOTES 6
1714 struct list_head *t;
1716 info->notes = NULL;
1717 info->prstatus = NULL;
1718 info->psinfo = NULL;
1719 info->fpu = NULL;
1720 #ifdef ELF_CORE_COPY_XFPREGS
1721 info->xfpu = NULL;
1722 #endif
1723 INIT_LIST_HEAD(&info->thread_list);
1725 info->notes = kmalloc(NUM_NOTES * sizeof(struct memelfnote),
1726 GFP_KERNEL);
1727 if (!info->notes)
1728 return 0;
1729 info->psinfo = kmalloc(sizeof(*info->psinfo), GFP_KERNEL);
1730 if (!info->psinfo)
1731 return 0;
1732 info->prstatus = kmalloc(sizeof(*info->prstatus), GFP_KERNEL);
1733 if (!info->prstatus)
1734 return 0;
1735 info->fpu = kmalloc(sizeof(*info->fpu), GFP_KERNEL);
1736 if (!info->fpu)
1737 return 0;
1738 #ifdef ELF_CORE_COPY_XFPREGS
1739 info->xfpu = kmalloc(sizeof(*info->xfpu), GFP_KERNEL);
1740 if (!info->xfpu)
1741 return 0;
1742 #endif
1744 info->thread_status_size = 0;
1745 if (signr) {
1746 struct core_thread *ct;
1747 struct elf_thread_status *ets;
1749 for (ct = current->mm->core_state->dumper.next;
1750 ct; ct = ct->next) {
1751 ets = kzalloc(sizeof(*ets), GFP_KERNEL);
1752 if (!ets)
1753 return 0;
1755 ets->thread = ct->task;
1756 list_add(&ets->list, &info->thread_list);
1759 list_for_each(t, &info->thread_list) {
1760 int sz;
1762 ets = list_entry(t, struct elf_thread_status, list);
1763 sz = elf_dump_thread_status(signr, ets);
1764 info->thread_status_size += sz;
1767 /* now collect the dump for the current */
1768 memset(info->prstatus, 0, sizeof(*info->prstatus));
1769 fill_prstatus(info->prstatus, current, signr);
1770 elf_core_copy_regs(&info->prstatus->pr_reg, regs);
1772 /* Set up header */
1773 fill_elf_header(elf, phdrs, ELF_ARCH, ELF_CORE_EFLAGS, ELF_OSABI);
1776 * Set up the notes in similar form to SVR4 core dumps made
1777 * with info from their /proc.
1780 fill_note(info->notes + 0, "CORE", NT_PRSTATUS,
1781 sizeof(*info->prstatus), info->prstatus);
1782 fill_psinfo(info->psinfo, current->group_leader, current->mm);
1783 fill_note(info->notes + 1, "CORE", NT_PRPSINFO,
1784 sizeof(*info->psinfo), info->psinfo);
1786 info->numnote = 2;
1788 fill_auxv_note(&info->notes[info->numnote++], current->mm);
1790 /* Try to dump the FPU. */
1791 info->prstatus->pr_fpvalid = elf_core_copy_task_fpregs(current, regs,
1792 info->fpu);
1793 if (info->prstatus->pr_fpvalid)
1794 fill_note(info->notes + info->numnote++,
1795 "CORE", NT_PRFPREG, sizeof(*info->fpu), info->fpu);
1796 #ifdef ELF_CORE_COPY_XFPREGS
1797 if (elf_core_copy_task_xfpregs(current, info->xfpu))
1798 fill_note(info->notes + info->numnote++,
1799 "LINUX", ELF_CORE_XFPREG_TYPE,
1800 sizeof(*info->xfpu), info->xfpu);
1801 #endif
1803 return 1;
1805 #undef NUM_NOTES
1808 static size_t get_note_info_size(struct elf_note_info *info)
1810 int sz = 0;
1811 int i;
1813 for (i = 0; i < info->numnote; i++)
1814 sz += notesize(info->notes + i);
1816 sz += info->thread_status_size;
1818 return sz;
1821 static int write_note_info(struct elf_note_info *info,
1822 struct file *file, loff_t *foffset)
1824 int i;
1825 struct list_head *t;
1827 for (i = 0; i < info->numnote; i++)
1828 if (!writenote(info->notes + i, file, foffset))
1829 return 0;
1831 /* write out the thread status notes section */
1832 list_for_each(t, &info->thread_list) {
1833 struct elf_thread_status *tmp =
1834 list_entry(t, struct elf_thread_status, list);
1836 for (i = 0; i < tmp->num_notes; i++)
1837 if (!writenote(&tmp->notes[i], file, foffset))
1838 return 0;
1841 return 1;
1844 static void free_note_info(struct elf_note_info *info)
1846 while (!list_empty(&info->thread_list)) {
1847 struct list_head *tmp = info->thread_list.next;
1848 list_del(tmp);
1849 kfree(list_entry(tmp, struct elf_thread_status, list));
1852 kfree(info->prstatus);
1853 kfree(info->psinfo);
1854 kfree(info->notes);
1855 kfree(info->fpu);
1856 #ifdef ELF_CORE_COPY_XFPREGS
1857 kfree(info->xfpu);
1858 #endif
1861 #endif
1863 static struct vm_area_struct *first_vma(struct task_struct *tsk,
1864 struct vm_area_struct *gate_vma)
1866 struct vm_area_struct *ret = tsk->mm->mmap;
1868 if (ret)
1869 return ret;
1870 return gate_vma;
1873 * Helper function for iterating across a vma list. It ensures that the caller
1874 * will visit `gate_vma' prior to terminating the search.
1876 static struct vm_area_struct *next_vma(struct vm_area_struct *this_vma,
1877 struct vm_area_struct *gate_vma)
1879 struct vm_area_struct *ret;
1881 ret = this_vma->vm_next;
1882 if (ret)
1883 return ret;
1884 if (this_vma == gate_vma)
1885 return NULL;
1886 return gate_vma;
1890 * Actual dumper
1892 * This is a two-pass process; first we find the offsets of the bits,
1893 * and then they are actually written out. If we run out of core limit
1894 * we just truncate.
1896 static int elf_core_dump(long signr, struct pt_regs *regs, struct file *file, unsigned long limit)
1898 int has_dumped = 0;
1899 mm_segment_t fs;
1900 int segs;
1901 size_t size = 0;
1902 struct vm_area_struct *vma, *gate_vma;
1903 struct elfhdr *elf = NULL;
1904 loff_t offset = 0, dataoff, foffset;
1905 unsigned long mm_flags;
1906 struct elf_note_info info;
1909 * We no longer stop all VM operations.
1911 * This is because those proceses that could possibly change map_count
1912 * or the mmap / vma pages are now blocked in do_exit on current
1913 * finishing this core dump.
1915 * Only ptrace can touch these memory addresses, but it doesn't change
1916 * the map_count or the pages allocated. So no possibility of crashing
1917 * exists while dumping the mm->vm_next areas to the core file.
1920 /* alloc memory for large data structures: too large to be on stack */
1921 elf = kmalloc(sizeof(*elf), GFP_KERNEL);
1922 if (!elf)
1923 goto out;
1925 segs = current->mm->map_count;
1926 #ifdef ELF_CORE_EXTRA_PHDRS
1927 segs += ELF_CORE_EXTRA_PHDRS;
1928 #endif
1930 gate_vma = get_gate_vma(current);
1931 if (gate_vma != NULL)
1932 segs++;
1935 * Collect all the non-memory information about the process for the
1936 * notes. This also sets up the file header.
1938 if (!fill_note_info(elf, segs + 1, /* including notes section */
1939 &info, signr, regs))
1940 goto cleanup;
1942 has_dumped = 1;
1943 current->flags |= PF_DUMPCORE;
1945 fs = get_fs();
1946 set_fs(KERNEL_DS);
1948 DUMP_WRITE(elf, sizeof(*elf));
1949 offset += sizeof(*elf); /* Elf header */
1950 offset += (segs + 1) * sizeof(struct elf_phdr); /* Program headers */
1951 foffset = offset;
1953 /* Write notes phdr entry */
1955 struct elf_phdr phdr;
1956 size_t sz = get_note_info_size(&info);
1958 sz += elf_coredump_extra_notes_size();
1960 fill_elf_note_phdr(&phdr, sz, offset);
1961 offset += sz;
1962 DUMP_WRITE(&phdr, sizeof(phdr));
1965 dataoff = offset = roundup(offset, ELF_EXEC_PAGESIZE);
1968 * We must use the same mm->flags while dumping core to avoid
1969 * inconsistency between the program headers and bodies, otherwise an
1970 * unusable core file can be generated.
1972 mm_flags = current->mm->flags;
1974 /* Write program headers for segments dump */
1975 for (vma = first_vma(current, gate_vma); vma != NULL;
1976 vma = next_vma(vma, gate_vma)) {
1977 struct elf_phdr phdr;
1979 phdr.p_type = PT_LOAD;
1980 phdr.p_offset = offset;
1981 phdr.p_vaddr = vma->vm_start;
1982 phdr.p_paddr = 0;
1983 phdr.p_filesz = vma_dump_size(vma, mm_flags);
1984 phdr.p_memsz = vma->vm_end - vma->vm_start;
1985 offset += phdr.p_filesz;
1986 phdr.p_flags = vma->vm_flags & VM_READ ? PF_R : 0;
1987 if (vma->vm_flags & VM_WRITE)
1988 phdr.p_flags |= PF_W;
1989 if (vma->vm_flags & VM_EXEC)
1990 phdr.p_flags |= PF_X;
1991 phdr.p_align = ELF_EXEC_PAGESIZE;
1993 DUMP_WRITE(&phdr, sizeof(phdr));
1996 #ifdef ELF_CORE_WRITE_EXTRA_PHDRS
1997 ELF_CORE_WRITE_EXTRA_PHDRS;
1998 #endif
2000 /* write out the notes section */
2001 if (!write_note_info(&info, file, &foffset))
2002 goto end_coredump;
2004 if (elf_coredump_extra_notes_write(file, &foffset))
2005 goto end_coredump;
2007 /* Align to page */
2008 DUMP_SEEK(dataoff - foffset);
2010 for (vma = first_vma(current, gate_vma); vma != NULL;
2011 vma = next_vma(vma, gate_vma)) {
2012 unsigned long addr;
2013 unsigned long end;
2015 end = vma->vm_start + vma_dump_size(vma, mm_flags);
2017 for (addr = vma->vm_start; addr < end; addr += PAGE_SIZE) {
2018 struct page *page;
2019 struct vm_area_struct *tmp_vma;
2021 if (get_user_pages(current, current->mm, addr, 1, 0, 1,
2022 &page, &tmp_vma) <= 0) {
2023 DUMP_SEEK(PAGE_SIZE);
2024 } else {
2025 if (page == ZERO_PAGE(0)) {
2026 if (!dump_seek(file, PAGE_SIZE)) {
2027 page_cache_release(page);
2028 goto end_coredump;
2030 } else {
2031 void *kaddr;
2032 flush_cache_page(tmp_vma, addr,
2033 page_to_pfn(page));
2034 kaddr = kmap(page);
2035 if ((size += PAGE_SIZE) > limit ||
2036 !dump_write(file, kaddr,
2037 PAGE_SIZE)) {
2038 kunmap(page);
2039 page_cache_release(page);
2040 goto end_coredump;
2042 kunmap(page);
2044 page_cache_release(page);
2049 #ifdef ELF_CORE_WRITE_EXTRA_DATA
2050 ELF_CORE_WRITE_EXTRA_DATA;
2051 #endif
2053 end_coredump:
2054 set_fs(fs);
2056 cleanup:
2057 free_note_info(&info);
2058 kfree(elf);
2059 out:
2060 return has_dumped;
2063 #endif /* USE_ELF_CORE_DUMP */
2065 static int __init init_elf_binfmt(void)
2067 return register_binfmt(&elf_format);
2070 static void __exit exit_elf_binfmt(void)
2072 /* Remove the COFF and ELF loaders. */
2073 unregister_binfmt(&elf_format);
2076 core_initcall(init_elf_binfmt);
2077 module_exit(exit_elf_binfmt);
2078 MODULE_LICENSE("GPL");