Linux 2.6.26-rc5
[linux-2.6/openmoko-kernel/knife-kernel.git] / fs / binfmt_elf.c
blob0fa95b198e6e9c89f5f4166b45666bdf6171c730
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/a.out.h>
20 #include <linux/errno.h>
21 #include <linux/signal.h>
22 #include <linux/binfmts.h>
23 #include <linux/string.h>
24 #include <linux/file.h>
25 #include <linux/fcntl.h>
26 #include <linux/ptrace.h>
27 #include <linux/slab.h>
28 #include <linux/shm.h>
29 #include <linux/personality.h>
30 #include <linux/elfcore.h>
31 #include <linux/init.h>
32 #include <linux/highuid.h>
33 #include <linux/smp.h>
34 #include <linux/compiler.h>
35 #include <linux/highmem.h>
36 #include <linux/pagemap.h>
37 #include <linux/security.h>
38 #include <linux/syscalls.h>
39 #include <linux/random.h>
40 #include <linux/elf.h>
41 #include <linux/utsname.h>
42 #include <asm/uaccess.h>
43 #include <asm/param.h>
44 #include <asm/page.h>
46 static int load_elf_binary(struct linux_binprm *bprm, struct pt_regs *regs);
47 static int load_elf_library(struct file *);
48 static unsigned long elf_map(struct file *, unsigned long, struct elf_phdr *,
49 int, int, unsigned long);
52 * If we don't support core dumping, then supply a NULL so we
53 * don't even try.
55 #if defined(USE_ELF_CORE_DUMP) && defined(CONFIG_ELF_CORE)
56 static int elf_core_dump(long signr, struct pt_regs *regs, struct file *file, unsigned long limit);
57 #else
58 #define elf_core_dump NULL
59 #endif
61 #if ELF_EXEC_PAGESIZE > PAGE_SIZE
62 #define ELF_MIN_ALIGN ELF_EXEC_PAGESIZE
63 #else
64 #define ELF_MIN_ALIGN PAGE_SIZE
65 #endif
67 #ifndef ELF_CORE_EFLAGS
68 #define ELF_CORE_EFLAGS 0
69 #endif
71 #define ELF_PAGESTART(_v) ((_v) & ~(unsigned long)(ELF_MIN_ALIGN-1))
72 #define ELF_PAGEOFFSET(_v) ((_v) & (ELF_MIN_ALIGN-1))
73 #define ELF_PAGEALIGN(_v) (((_v) + ELF_MIN_ALIGN - 1) & ~(ELF_MIN_ALIGN - 1))
75 static struct linux_binfmt elf_format = {
76 .module = THIS_MODULE,
77 .load_binary = load_elf_binary,
78 .load_shlib = load_elf_library,
79 .core_dump = elf_core_dump,
80 .min_coredump = ELF_EXEC_PAGESIZE,
81 .hasvdso = 1
84 #define BAD_ADDR(x) ((unsigned long)(x) >= TASK_SIZE)
86 static int set_brk(unsigned long start, unsigned long end)
88 start = ELF_PAGEALIGN(start);
89 end = ELF_PAGEALIGN(end);
90 if (end > start) {
91 unsigned long addr;
92 down_write(&current->mm->mmap_sem);
93 addr = do_brk(start, end - start);
94 up_write(&current->mm->mmap_sem);
95 if (BAD_ADDR(addr))
96 return addr;
98 current->mm->start_brk = current->mm->brk = end;
99 return 0;
102 /* We need to explicitly zero any fractional pages
103 after the data section (i.e. bss). This would
104 contain the junk from the file that should not
105 be in memory
107 static int padzero(unsigned long elf_bss)
109 unsigned long nbyte;
111 nbyte = ELF_PAGEOFFSET(elf_bss);
112 if (nbyte) {
113 nbyte = ELF_MIN_ALIGN - nbyte;
114 if (clear_user((void __user *) elf_bss, nbyte))
115 return -EFAULT;
117 return 0;
120 /* Let's use some macros to make this stack manipulation a little clearer */
121 #ifdef CONFIG_STACK_GROWSUP
122 #define STACK_ADD(sp, items) ((elf_addr_t __user *)(sp) + (items))
123 #define STACK_ROUND(sp, items) \
124 ((15 + (unsigned long) ((sp) + (items))) &~ 15UL)
125 #define STACK_ALLOC(sp, len) ({ \
126 elf_addr_t __user *old_sp = (elf_addr_t __user *)sp; sp += len; \
127 old_sp; })
128 #else
129 #define STACK_ADD(sp, items) ((elf_addr_t __user *)(sp) - (items))
130 #define STACK_ROUND(sp, items) \
131 (((unsigned long) (sp - items)) &~ 15UL)
132 #define STACK_ALLOC(sp, len) ({ sp -= len ; sp; })
133 #endif
135 static int
136 create_elf_tables(struct linux_binprm *bprm, struct elfhdr *exec,
137 unsigned long load_addr, unsigned long interp_load_addr)
139 unsigned long p = bprm->p;
140 int argc = bprm->argc;
141 int envc = bprm->envc;
142 elf_addr_t __user *argv;
143 elf_addr_t __user *envp;
144 elf_addr_t __user *sp;
145 elf_addr_t __user *u_platform;
146 const char *k_platform = ELF_PLATFORM;
147 int items;
148 elf_addr_t *elf_info;
149 int ei_index = 0;
150 struct task_struct *tsk = current;
151 struct vm_area_struct *vma;
154 * In some cases (e.g. Hyper-Threading), we want to avoid L1
155 * evictions by the processes running on the same package. One
156 * thing we can do is to shuffle the initial stack for them.
159 p = arch_align_stack(p);
162 * If this architecture has a platform capability string, copy it
163 * to userspace. In some cases (Sparc), this info is impossible
164 * for userspace to get any other way, in others (i386) it is
165 * merely difficult.
167 u_platform = NULL;
168 if (k_platform) {
169 size_t len = strlen(k_platform) + 1;
171 u_platform = (elf_addr_t __user *)STACK_ALLOC(p, len);
172 if (__copy_to_user(u_platform, k_platform, len))
173 return -EFAULT;
176 /* Create the ELF interpreter info */
177 elf_info = (elf_addr_t *)current->mm->saved_auxv;
178 /* update AT_VECTOR_SIZE_BASE if the number of NEW_AUX_ENT() changes */
179 #define NEW_AUX_ENT(id, val) \
180 do { \
181 elf_info[ei_index++] = id; \
182 elf_info[ei_index++] = val; \
183 } while (0)
185 #ifdef ARCH_DLINFO
187 * ARCH_DLINFO must come first so PPC can do its special alignment of
188 * AUXV.
189 * update AT_VECTOR_SIZE_ARCH if the number of NEW_AUX_ENT() in
190 * ARCH_DLINFO changes
192 ARCH_DLINFO;
193 #endif
194 NEW_AUX_ENT(AT_HWCAP, ELF_HWCAP);
195 NEW_AUX_ENT(AT_PAGESZ, ELF_EXEC_PAGESIZE);
196 NEW_AUX_ENT(AT_CLKTCK, CLOCKS_PER_SEC);
197 NEW_AUX_ENT(AT_PHDR, load_addr + exec->e_phoff);
198 NEW_AUX_ENT(AT_PHENT, sizeof(struct elf_phdr));
199 NEW_AUX_ENT(AT_PHNUM, exec->e_phnum);
200 NEW_AUX_ENT(AT_BASE, interp_load_addr);
201 NEW_AUX_ENT(AT_FLAGS, 0);
202 NEW_AUX_ENT(AT_ENTRY, exec->e_entry);
203 NEW_AUX_ENT(AT_UID, tsk->uid);
204 NEW_AUX_ENT(AT_EUID, tsk->euid);
205 NEW_AUX_ENT(AT_GID, tsk->gid);
206 NEW_AUX_ENT(AT_EGID, tsk->egid);
207 NEW_AUX_ENT(AT_SECURE, security_bprm_secureexec(bprm));
208 if (k_platform) {
209 NEW_AUX_ENT(AT_PLATFORM,
210 (elf_addr_t)(unsigned long)u_platform);
212 if (bprm->interp_flags & BINPRM_FLAGS_EXECFD) {
213 NEW_AUX_ENT(AT_EXECFD, bprm->interp_data);
215 #undef NEW_AUX_ENT
216 /* AT_NULL is zero; clear the rest too */
217 memset(&elf_info[ei_index], 0,
218 sizeof current->mm->saved_auxv - ei_index * sizeof elf_info[0]);
220 /* And advance past the AT_NULL entry. */
221 ei_index += 2;
223 sp = STACK_ADD(p, ei_index);
225 items = (argc + 1) + (envc + 1) + 1;
226 bprm->p = STACK_ROUND(sp, items);
228 /* Point sp at the lowest address on the stack */
229 #ifdef CONFIG_STACK_GROWSUP
230 sp = (elf_addr_t __user *)bprm->p - items - ei_index;
231 bprm->exec = (unsigned long)sp; /* XXX: PARISC HACK */
232 #else
233 sp = (elf_addr_t __user *)bprm->p;
234 #endif
238 * Grow the stack manually; some architectures have a limit on how
239 * far ahead a user-space access may be in order to grow the stack.
241 vma = find_extend_vma(current->mm, bprm->p);
242 if (!vma)
243 return -EFAULT;
245 /* Now, let's put argc (and argv, envp if appropriate) on the stack */
246 if (__put_user(argc, sp++))
247 return -EFAULT;
248 argv = sp;
249 envp = argv + argc + 1;
251 /* Populate argv and envp */
252 p = current->mm->arg_end = current->mm->arg_start;
253 while (argc-- > 0) {
254 size_t len;
255 if (__put_user((elf_addr_t)p, argv++))
256 return -EFAULT;
257 len = strnlen_user((void __user *)p, MAX_ARG_STRLEN);
258 if (!len || len > MAX_ARG_STRLEN)
259 return -EINVAL;
260 p += len;
262 if (__put_user(0, argv))
263 return -EFAULT;
264 current->mm->arg_end = current->mm->env_start = p;
265 while (envc-- > 0) {
266 size_t len;
267 if (__put_user((elf_addr_t)p, envp++))
268 return -EFAULT;
269 len = strnlen_user((void __user *)p, MAX_ARG_STRLEN);
270 if (!len || len > MAX_ARG_STRLEN)
271 return -EINVAL;
272 p += len;
274 if (__put_user(0, envp))
275 return -EFAULT;
276 current->mm->env_end = p;
278 /* Put the elf_info on the stack in the right place. */
279 sp = (elf_addr_t __user *)envp + 1;
280 if (copy_to_user(sp, elf_info, ei_index * sizeof(elf_addr_t)))
281 return -EFAULT;
282 return 0;
285 #ifndef elf_map
287 static unsigned long elf_map(struct file *filep, unsigned long addr,
288 struct elf_phdr *eppnt, int prot, int type,
289 unsigned long total_size)
291 unsigned long map_addr;
292 unsigned long size = eppnt->p_filesz + ELF_PAGEOFFSET(eppnt->p_vaddr);
293 unsigned long off = eppnt->p_offset - ELF_PAGEOFFSET(eppnt->p_vaddr);
294 addr = ELF_PAGESTART(addr);
295 size = ELF_PAGEALIGN(size);
297 /* mmap() will return -EINVAL if given a zero size, but a
298 * segment with zero filesize is perfectly valid */
299 if (!size)
300 return addr;
302 down_write(&current->mm->mmap_sem);
304 * total_size is the size of the ELF (interpreter) image.
305 * The _first_ mmap needs to know the full size, otherwise
306 * randomization might put this image into an overlapping
307 * position with the ELF binary image. (since size < total_size)
308 * So we first map the 'big' image - and unmap the remainder at
309 * the end. (which unmap is needed for ELF images with holes.)
311 if (total_size) {
312 total_size = ELF_PAGEALIGN(total_size);
313 map_addr = do_mmap(filep, addr, total_size, prot, type, off);
314 if (!BAD_ADDR(map_addr))
315 do_munmap(current->mm, map_addr+size, total_size-size);
316 } else
317 map_addr = do_mmap(filep, addr, size, prot, type, off);
319 up_write(&current->mm->mmap_sem);
320 return(map_addr);
323 #endif /* !elf_map */
325 static unsigned long total_mapping_size(struct elf_phdr *cmds, int nr)
327 int i, first_idx = -1, last_idx = -1;
329 for (i = 0; i < nr; i++) {
330 if (cmds[i].p_type == PT_LOAD) {
331 last_idx = i;
332 if (first_idx == -1)
333 first_idx = i;
336 if (first_idx == -1)
337 return 0;
339 return cmds[last_idx].p_vaddr + cmds[last_idx].p_memsz -
340 ELF_PAGESTART(cmds[first_idx].p_vaddr);
344 /* This is much more generalized than the library routine read function,
345 so we keep this separate. Technically the library read function
346 is only provided so that we can read a.out libraries that have
347 an ELF header */
349 static unsigned long load_elf_interp(struct elfhdr *interp_elf_ex,
350 struct file *interpreter, unsigned long *interp_map_addr,
351 unsigned long no_base)
353 struct elf_phdr *elf_phdata;
354 struct elf_phdr *eppnt;
355 unsigned long load_addr = 0;
356 int load_addr_set = 0;
357 unsigned long last_bss = 0, elf_bss = 0;
358 unsigned long error = ~0UL;
359 unsigned long total_size;
360 int retval, i, size;
362 /* First of all, some simple consistency checks */
363 if (interp_elf_ex->e_type != ET_EXEC &&
364 interp_elf_ex->e_type != ET_DYN)
365 goto out;
366 if (!elf_check_arch(interp_elf_ex))
367 goto out;
368 if (!interpreter->f_op || !interpreter->f_op->mmap)
369 goto out;
372 * If the size of this structure has changed, then punt, since
373 * we will be doing the wrong thing.
375 if (interp_elf_ex->e_phentsize != sizeof(struct elf_phdr))
376 goto out;
377 if (interp_elf_ex->e_phnum < 1 ||
378 interp_elf_ex->e_phnum > 65536U / sizeof(struct elf_phdr))
379 goto out;
381 /* Now read in all of the header information */
382 size = sizeof(struct elf_phdr) * interp_elf_ex->e_phnum;
383 if (size > ELF_MIN_ALIGN)
384 goto out;
385 elf_phdata = kmalloc(size, GFP_KERNEL);
386 if (!elf_phdata)
387 goto out;
389 retval = kernel_read(interpreter, interp_elf_ex->e_phoff,
390 (char *)elf_phdata,size);
391 error = -EIO;
392 if (retval != size) {
393 if (retval < 0)
394 error = retval;
395 goto out_close;
398 total_size = total_mapping_size(elf_phdata, interp_elf_ex->e_phnum);
399 if (!total_size) {
400 error = -EINVAL;
401 goto out_close;
404 eppnt = elf_phdata;
405 for (i = 0; i < interp_elf_ex->e_phnum; i++, eppnt++) {
406 if (eppnt->p_type == PT_LOAD) {
407 int elf_type = MAP_PRIVATE | MAP_DENYWRITE;
408 int elf_prot = 0;
409 unsigned long vaddr = 0;
410 unsigned long k, map_addr;
412 if (eppnt->p_flags & PF_R)
413 elf_prot = PROT_READ;
414 if (eppnt->p_flags & PF_W)
415 elf_prot |= PROT_WRITE;
416 if (eppnt->p_flags & PF_X)
417 elf_prot |= PROT_EXEC;
418 vaddr = eppnt->p_vaddr;
419 if (interp_elf_ex->e_type == ET_EXEC || load_addr_set)
420 elf_type |= MAP_FIXED;
421 else if (no_base && interp_elf_ex->e_type == ET_DYN)
422 load_addr = -vaddr;
424 map_addr = elf_map(interpreter, load_addr + vaddr,
425 eppnt, elf_prot, elf_type, total_size);
426 total_size = 0;
427 if (!*interp_map_addr)
428 *interp_map_addr = map_addr;
429 error = map_addr;
430 if (BAD_ADDR(map_addr))
431 goto out_close;
433 if (!load_addr_set &&
434 interp_elf_ex->e_type == ET_DYN) {
435 load_addr = map_addr - ELF_PAGESTART(vaddr);
436 load_addr_set = 1;
440 * Check to see if the section's size will overflow the
441 * allowed task size. Note that p_filesz must always be
442 * <= p_memsize so it's only necessary to check p_memsz.
444 k = load_addr + eppnt->p_vaddr;
445 if (BAD_ADDR(k) ||
446 eppnt->p_filesz > eppnt->p_memsz ||
447 eppnt->p_memsz > TASK_SIZE ||
448 TASK_SIZE - eppnt->p_memsz < k) {
449 error = -ENOMEM;
450 goto out_close;
454 * Find the end of the file mapping for this phdr, and
455 * keep track of the largest address we see for this.
457 k = load_addr + eppnt->p_vaddr + eppnt->p_filesz;
458 if (k > elf_bss)
459 elf_bss = k;
462 * Do the same thing for the memory mapping - between
463 * elf_bss and last_bss is the bss section.
465 k = load_addr + eppnt->p_memsz + eppnt->p_vaddr;
466 if (k > last_bss)
467 last_bss = k;
472 * Now fill out the bss section. First pad the last page up
473 * to the page boundary, and then perform a mmap to make sure
474 * that there are zero-mapped pages up to and including the
475 * last bss page.
477 if (padzero(elf_bss)) {
478 error = -EFAULT;
479 goto out_close;
482 /* What we have mapped so far */
483 elf_bss = ELF_PAGESTART(elf_bss + ELF_MIN_ALIGN - 1);
485 /* Map the last of the bss segment */
486 if (last_bss > elf_bss) {
487 down_write(&current->mm->mmap_sem);
488 error = do_brk(elf_bss, last_bss - elf_bss);
489 up_write(&current->mm->mmap_sem);
490 if (BAD_ADDR(error))
491 goto out_close;
494 error = load_addr;
496 out_close:
497 kfree(elf_phdata);
498 out:
499 return error;
503 * These are the functions used to load ELF style executables and shared
504 * libraries. There is no binary dependent code anywhere else.
507 #define INTERPRETER_NONE 0
508 #define INTERPRETER_ELF 2
510 #ifndef STACK_RND_MASK
511 #define STACK_RND_MASK (0x7ff >> (PAGE_SHIFT - 12)) /* 8MB of VA */
512 #endif
514 static unsigned long randomize_stack_top(unsigned long stack_top)
516 unsigned int random_variable = 0;
518 if ((current->flags & PF_RANDOMIZE) &&
519 !(current->personality & ADDR_NO_RANDOMIZE)) {
520 random_variable = get_random_int() & STACK_RND_MASK;
521 random_variable <<= PAGE_SHIFT;
523 #ifdef CONFIG_STACK_GROWSUP
524 return PAGE_ALIGN(stack_top) + random_variable;
525 #else
526 return PAGE_ALIGN(stack_top) - random_variable;
527 #endif
530 static int load_elf_binary(struct linux_binprm *bprm, struct pt_regs *regs)
532 struct file *interpreter = NULL; /* to shut gcc up */
533 unsigned long load_addr = 0, load_bias = 0;
534 int load_addr_set = 0;
535 char * elf_interpreter = NULL;
536 unsigned long error;
537 struct elf_phdr *elf_ppnt, *elf_phdata;
538 unsigned long elf_bss, elf_brk;
539 int elf_exec_fileno;
540 int retval, i;
541 unsigned int size;
542 unsigned long elf_entry;
543 unsigned long interp_load_addr = 0;
544 unsigned long start_code, end_code, start_data, end_data;
545 unsigned long reloc_func_desc = 0;
546 int executable_stack = EXSTACK_DEFAULT;
547 unsigned long def_flags = 0;
548 struct {
549 struct elfhdr elf_ex;
550 struct elfhdr interp_elf_ex;
551 struct exec interp_ex;
552 } *loc;
554 loc = kmalloc(sizeof(*loc), GFP_KERNEL);
555 if (!loc) {
556 retval = -ENOMEM;
557 goto out_ret;
560 /* Get the exec-header */
561 loc->elf_ex = *((struct elfhdr *)bprm->buf);
563 retval = -ENOEXEC;
564 /* First of all, some simple consistency checks */
565 if (memcmp(loc->elf_ex.e_ident, ELFMAG, SELFMAG) != 0)
566 goto out;
568 if (loc->elf_ex.e_type != ET_EXEC && loc->elf_ex.e_type != ET_DYN)
569 goto out;
570 if (!elf_check_arch(&loc->elf_ex))
571 goto out;
572 if (!bprm->file->f_op||!bprm->file->f_op->mmap)
573 goto out;
575 /* Now read in all of the header information */
576 if (loc->elf_ex.e_phentsize != sizeof(struct elf_phdr))
577 goto out;
578 if (loc->elf_ex.e_phnum < 1 ||
579 loc->elf_ex.e_phnum > 65536U / sizeof(struct elf_phdr))
580 goto out;
581 size = loc->elf_ex.e_phnum * sizeof(struct elf_phdr);
582 retval = -ENOMEM;
583 elf_phdata = kmalloc(size, GFP_KERNEL);
584 if (!elf_phdata)
585 goto out;
587 retval = kernel_read(bprm->file, loc->elf_ex.e_phoff,
588 (char *)elf_phdata, size);
589 if (retval != size) {
590 if (retval >= 0)
591 retval = -EIO;
592 goto out_free_ph;
595 retval = get_unused_fd();
596 if (retval < 0)
597 goto out_free_ph;
598 get_file(bprm->file);
599 fd_install(elf_exec_fileno = retval, bprm->file);
601 elf_ppnt = elf_phdata;
602 elf_bss = 0;
603 elf_brk = 0;
605 start_code = ~0UL;
606 end_code = 0;
607 start_data = 0;
608 end_data = 0;
610 for (i = 0; i < loc->elf_ex.e_phnum; i++) {
611 if (elf_ppnt->p_type == PT_INTERP) {
612 /* This is the program interpreter used for
613 * shared libraries - for now assume that this
614 * is an a.out format binary
616 retval = -ENOEXEC;
617 if (elf_ppnt->p_filesz > PATH_MAX ||
618 elf_ppnt->p_filesz < 2)
619 goto out_free_file;
621 retval = -ENOMEM;
622 elf_interpreter = kmalloc(elf_ppnt->p_filesz,
623 GFP_KERNEL);
624 if (!elf_interpreter)
625 goto out_free_file;
627 retval = kernel_read(bprm->file, elf_ppnt->p_offset,
628 elf_interpreter,
629 elf_ppnt->p_filesz);
630 if (retval != elf_ppnt->p_filesz) {
631 if (retval >= 0)
632 retval = -EIO;
633 goto out_free_interp;
635 /* make sure path is NULL terminated */
636 retval = -ENOEXEC;
637 if (elf_interpreter[elf_ppnt->p_filesz - 1] != '\0')
638 goto out_free_interp;
641 * The early SET_PERSONALITY here is so that the lookup
642 * for the interpreter happens in the namespace of the
643 * to-be-execed image. SET_PERSONALITY can select an
644 * alternate root.
646 * However, SET_PERSONALITY is NOT allowed to switch
647 * this task into the new images's memory mapping
648 * policy - that is, TASK_SIZE must still evaluate to
649 * that which is appropriate to the execing application.
650 * This is because exit_mmap() needs to have TASK_SIZE
651 * evaluate to the size of the old image.
653 * So if (say) a 64-bit application is execing a 32-bit
654 * application it is the architecture's responsibility
655 * to defer changing the value of TASK_SIZE until the
656 * switch really is going to happen - do this in
657 * flush_thread(). - akpm
659 SET_PERSONALITY(loc->elf_ex, 0);
661 interpreter = open_exec(elf_interpreter);
662 retval = PTR_ERR(interpreter);
663 if (IS_ERR(interpreter))
664 goto out_free_interp;
667 * If the binary is not readable then enforce
668 * mm->dumpable = 0 regardless of the interpreter's
669 * permissions.
671 if (file_permission(interpreter, MAY_READ) < 0)
672 bprm->interp_flags |= BINPRM_FLAGS_ENFORCE_NONDUMP;
674 retval = kernel_read(interpreter, 0, bprm->buf,
675 BINPRM_BUF_SIZE);
676 if (retval != BINPRM_BUF_SIZE) {
677 if (retval >= 0)
678 retval = -EIO;
679 goto out_free_dentry;
682 /* Get the exec headers */
683 loc->interp_ex = *((struct exec *)bprm->buf);
684 loc->interp_elf_ex = *((struct elfhdr *)bprm->buf);
685 break;
687 elf_ppnt++;
690 elf_ppnt = elf_phdata;
691 for (i = 0; i < loc->elf_ex.e_phnum; i++, elf_ppnt++)
692 if (elf_ppnt->p_type == PT_GNU_STACK) {
693 if (elf_ppnt->p_flags & PF_X)
694 executable_stack = EXSTACK_ENABLE_X;
695 else
696 executable_stack = EXSTACK_DISABLE_X;
697 break;
700 /* Some simple consistency checks for the interpreter */
701 if (elf_interpreter) {
702 retval = -ELIBBAD;
703 /* Not an ELF interpreter */
704 if (memcmp(loc->interp_elf_ex.e_ident, ELFMAG, SELFMAG) != 0)
705 goto out_free_dentry;
706 /* Verify the interpreter has a valid arch */
707 if (!elf_check_arch(&loc->interp_elf_ex))
708 goto out_free_dentry;
709 } else {
710 /* Executables without an interpreter also need a personality */
711 SET_PERSONALITY(loc->elf_ex, 0);
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, 0);
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;
731 arch_pick_mmap_layout(current->mm);
733 /* Do this so that we can load the interpreter, if need be. We will
734 change some of these later */
735 current->mm->free_area_cache = current->mm->mmap_base;
736 current->mm->cached_hole_size = 0;
737 retval = setup_arg_pages(bprm, randomize_stack_top(STACK_TOP),
738 executable_stack);
739 if (retval < 0) {
740 send_sig(SIGKILL, current, 0);
741 goto out_free_dentry;
744 current->mm->start_stack = bprm->p;
746 /* Now we do a little grungy work by mmaping the ELF image into
747 the correct location in memory. */
748 for(i = 0, elf_ppnt = elf_phdata;
749 i < loc->elf_ex.e_phnum; i++, elf_ppnt++) {
750 int elf_prot = 0, elf_flags;
751 unsigned long k, vaddr;
753 if (elf_ppnt->p_type != PT_LOAD)
754 continue;
756 if (unlikely (elf_brk > elf_bss)) {
757 unsigned long nbyte;
759 /* There was a PT_LOAD segment with p_memsz > p_filesz
760 before this one. Map anonymous pages, if needed,
761 and clear the area. */
762 retval = set_brk (elf_bss + load_bias,
763 elf_brk + load_bias);
764 if (retval) {
765 send_sig(SIGKILL, current, 0);
766 goto out_free_dentry;
768 nbyte = ELF_PAGEOFFSET(elf_bss);
769 if (nbyte) {
770 nbyte = ELF_MIN_ALIGN - nbyte;
771 if (nbyte > elf_brk - elf_bss)
772 nbyte = elf_brk - elf_bss;
773 if (clear_user((void __user *)elf_bss +
774 load_bias, nbyte)) {
776 * This bss-zeroing can fail if the ELF
777 * file specifies odd protections. So
778 * we don't check the return value
784 if (elf_ppnt->p_flags & PF_R)
785 elf_prot |= PROT_READ;
786 if (elf_ppnt->p_flags & PF_W)
787 elf_prot |= PROT_WRITE;
788 if (elf_ppnt->p_flags & PF_X)
789 elf_prot |= PROT_EXEC;
791 elf_flags = MAP_PRIVATE | MAP_DENYWRITE | MAP_EXECUTABLE;
793 vaddr = elf_ppnt->p_vaddr;
794 if (loc->elf_ex.e_type == ET_EXEC || load_addr_set) {
795 elf_flags |= MAP_FIXED;
796 } else if (loc->elf_ex.e_type == ET_DYN) {
797 /* Try and get dynamic programs out of the way of the
798 * default mmap base, as well as whatever program they
799 * might try to exec. This is because the brk will
800 * follow the loader, and is not movable. */
801 #ifdef CONFIG_X86
802 load_bias = 0;
803 #else
804 load_bias = ELF_PAGESTART(ELF_ET_DYN_BASE - vaddr);
805 #endif
808 error = elf_map(bprm->file, load_bias + vaddr, elf_ppnt,
809 elf_prot, elf_flags, 0);
810 if (BAD_ADDR(error)) {
811 send_sig(SIGKILL, current, 0);
812 retval = IS_ERR((void *)error) ?
813 PTR_ERR((void*)error) : -EINVAL;
814 goto out_free_dentry;
817 if (!load_addr_set) {
818 load_addr_set = 1;
819 load_addr = (elf_ppnt->p_vaddr - elf_ppnt->p_offset);
820 if (loc->elf_ex.e_type == ET_DYN) {
821 load_bias += error -
822 ELF_PAGESTART(load_bias + vaddr);
823 load_addr += load_bias;
824 reloc_func_desc = load_bias;
827 k = elf_ppnt->p_vaddr;
828 if (k < start_code)
829 start_code = k;
830 if (start_data < k)
831 start_data = k;
834 * Check to see if the section's size will overflow the
835 * allowed task size. Note that p_filesz must always be
836 * <= p_memsz so it is only necessary to check p_memsz.
838 if (BAD_ADDR(k) || elf_ppnt->p_filesz > elf_ppnt->p_memsz ||
839 elf_ppnt->p_memsz > TASK_SIZE ||
840 TASK_SIZE - elf_ppnt->p_memsz < k) {
841 /* set_brk can never work. Avoid overflows. */
842 send_sig(SIGKILL, current, 0);
843 retval = -EINVAL;
844 goto out_free_dentry;
847 k = elf_ppnt->p_vaddr + elf_ppnt->p_filesz;
849 if (k > elf_bss)
850 elf_bss = k;
851 if ((elf_ppnt->p_flags & PF_X) && end_code < k)
852 end_code = k;
853 if (end_data < k)
854 end_data = k;
855 k = elf_ppnt->p_vaddr + elf_ppnt->p_memsz;
856 if (k > elf_brk)
857 elf_brk = k;
860 loc->elf_ex.e_entry += load_bias;
861 elf_bss += load_bias;
862 elf_brk += load_bias;
863 start_code += load_bias;
864 end_code += load_bias;
865 start_data += load_bias;
866 end_data += load_bias;
868 /* Calling set_brk effectively mmaps the pages that we need
869 * for the bss and break sections. We must do this before
870 * mapping in the interpreter, to make sure it doesn't wind
871 * up getting placed where the bss needs to go.
873 retval = set_brk(elf_bss, elf_brk);
874 if (retval) {
875 send_sig(SIGKILL, current, 0);
876 goto out_free_dentry;
878 if (likely(elf_bss != elf_brk) && unlikely(padzero(elf_bss))) {
879 send_sig(SIGSEGV, current, 0);
880 retval = -EFAULT; /* Nobody gets to see this, but.. */
881 goto out_free_dentry;
884 if (elf_interpreter) {
885 unsigned long uninitialized_var(interp_map_addr);
887 elf_entry = load_elf_interp(&loc->interp_elf_ex,
888 interpreter,
889 &interp_map_addr,
890 load_bias);
891 if (!IS_ERR((void *)elf_entry)) {
893 * load_elf_interp() returns relocation
894 * adjustment
896 interp_load_addr = elf_entry;
897 elf_entry += loc->interp_elf_ex.e_entry;
899 if (BAD_ADDR(elf_entry)) {
900 force_sig(SIGSEGV, current);
901 retval = IS_ERR((void *)elf_entry) ?
902 (int)elf_entry : -EINVAL;
903 goto out_free_dentry;
905 reloc_func_desc = interp_load_addr;
907 allow_write_access(interpreter);
908 fput(interpreter);
909 kfree(elf_interpreter);
910 } else {
911 elf_entry = loc->elf_ex.e_entry;
912 if (BAD_ADDR(elf_entry)) {
913 force_sig(SIGSEGV, current);
914 retval = -EINVAL;
915 goto out_free_dentry;
919 kfree(elf_phdata);
921 sys_close(elf_exec_fileno);
923 set_binfmt(&elf_format);
925 #ifdef ARCH_HAS_SETUP_ADDITIONAL_PAGES
926 retval = arch_setup_additional_pages(bprm, executable_stack);
927 if (retval < 0) {
928 send_sig(SIGKILL, current, 0);
929 goto out;
931 #endif /* ARCH_HAS_SETUP_ADDITIONAL_PAGES */
933 compute_creds(bprm);
934 current->flags &= ~PF_FORKNOEXEC;
935 retval = create_elf_tables(bprm, &loc->elf_ex,
936 load_addr, interp_load_addr);
937 if (retval < 0) {
938 send_sig(SIGKILL, current, 0);
939 goto out;
941 /* N.B. passed_fileno might not be initialized? */
942 current->mm->end_code = end_code;
943 current->mm->start_code = start_code;
944 current->mm->start_data = start_data;
945 current->mm->end_data = end_data;
946 current->mm->start_stack = bprm->p;
948 #ifdef arch_randomize_brk
949 if ((current->flags & PF_RANDOMIZE) && (randomize_va_space > 1))
950 current->mm->brk = current->mm->start_brk =
951 arch_randomize_brk(current->mm);
952 #endif
954 if (current->personality & MMAP_PAGE_ZERO) {
955 /* Why this, you ask??? Well SVr4 maps page 0 as read-only,
956 and some applications "depend" upon this behavior.
957 Since we do not have the power to recompile these, we
958 emulate the SVr4 behavior. Sigh. */
959 down_write(&current->mm->mmap_sem);
960 error = do_mmap(NULL, 0, PAGE_SIZE, PROT_READ | PROT_EXEC,
961 MAP_FIXED | MAP_PRIVATE, 0);
962 up_write(&current->mm->mmap_sem);
965 #ifdef ELF_PLAT_INIT
967 * The ABI may specify that certain registers be set up in special
968 * ways (on i386 %edx is the address of a DT_FINI function, for
969 * example. In addition, it may also specify (eg, PowerPC64 ELF)
970 * that the e_entry field is the address of the function descriptor
971 * for the startup routine, rather than the address of the startup
972 * routine itself. This macro performs whatever initialization to
973 * the regs structure is required as well as any relocations to the
974 * function descriptor entries when executing dynamically links apps.
976 ELF_PLAT_INIT(regs, reloc_func_desc);
977 #endif
979 start_thread(regs, elf_entry, bprm->p);
980 if (unlikely(current->ptrace & PT_PTRACED)) {
981 if (current->ptrace & PT_TRACE_EXEC)
982 ptrace_notify ((PTRACE_EVENT_EXEC << 8) | SIGTRAP);
983 else
984 send_sig(SIGTRAP, current, 0);
986 retval = 0;
987 out:
988 kfree(loc);
989 out_ret:
990 return retval;
992 /* error cleanup */
993 out_free_dentry:
994 allow_write_access(interpreter);
995 if (interpreter)
996 fput(interpreter);
997 out_free_interp:
998 kfree(elf_interpreter);
999 out_free_file:
1000 sys_close(elf_exec_fileno);
1001 out_free_ph:
1002 kfree(elf_phdata);
1003 goto out;
1006 /* This is really simpleminded and specialized - we are loading an
1007 a.out library that is given an ELF header. */
1008 static int load_elf_library(struct file *file)
1010 struct elf_phdr *elf_phdata;
1011 struct elf_phdr *eppnt;
1012 unsigned long elf_bss, bss, len;
1013 int retval, error, i, j;
1014 struct elfhdr elf_ex;
1016 error = -ENOEXEC;
1017 retval = kernel_read(file, 0, (char *)&elf_ex, sizeof(elf_ex));
1018 if (retval != sizeof(elf_ex))
1019 goto out;
1021 if (memcmp(elf_ex.e_ident, ELFMAG, SELFMAG) != 0)
1022 goto out;
1024 /* First of all, some simple consistency checks */
1025 if (elf_ex.e_type != ET_EXEC || elf_ex.e_phnum > 2 ||
1026 !elf_check_arch(&elf_ex) || !file->f_op || !file->f_op->mmap)
1027 goto out;
1029 /* Now read in all of the header information */
1031 j = sizeof(struct elf_phdr) * elf_ex.e_phnum;
1032 /* j < ELF_MIN_ALIGN because elf_ex.e_phnum <= 2 */
1034 error = -ENOMEM;
1035 elf_phdata = kmalloc(j, GFP_KERNEL);
1036 if (!elf_phdata)
1037 goto out;
1039 eppnt = elf_phdata;
1040 error = -ENOEXEC;
1041 retval = kernel_read(file, elf_ex.e_phoff, (char *)eppnt, j);
1042 if (retval != j)
1043 goto out_free_ph;
1045 for (j = 0, i = 0; i<elf_ex.e_phnum; i++)
1046 if ((eppnt + i)->p_type == PT_LOAD)
1047 j++;
1048 if (j != 1)
1049 goto out_free_ph;
1051 while (eppnt->p_type != PT_LOAD)
1052 eppnt++;
1054 /* Now use mmap to map the library into memory. */
1055 down_write(&current->mm->mmap_sem);
1056 error = do_mmap(file,
1057 ELF_PAGESTART(eppnt->p_vaddr),
1058 (eppnt->p_filesz +
1059 ELF_PAGEOFFSET(eppnt->p_vaddr)),
1060 PROT_READ | PROT_WRITE | PROT_EXEC,
1061 MAP_FIXED | MAP_PRIVATE | MAP_DENYWRITE,
1062 (eppnt->p_offset -
1063 ELF_PAGEOFFSET(eppnt->p_vaddr)));
1064 up_write(&current->mm->mmap_sem);
1065 if (error != ELF_PAGESTART(eppnt->p_vaddr))
1066 goto out_free_ph;
1068 elf_bss = eppnt->p_vaddr + eppnt->p_filesz;
1069 if (padzero(elf_bss)) {
1070 error = -EFAULT;
1071 goto out_free_ph;
1074 len = ELF_PAGESTART(eppnt->p_filesz + eppnt->p_vaddr +
1075 ELF_MIN_ALIGN - 1);
1076 bss = eppnt->p_memsz + eppnt->p_vaddr;
1077 if (bss > len) {
1078 down_write(&current->mm->mmap_sem);
1079 do_brk(len, bss - len);
1080 up_write(&current->mm->mmap_sem);
1082 error = 0;
1084 out_free_ph:
1085 kfree(elf_phdata);
1086 out:
1087 return error;
1091 * Note that some platforms still use traditional core dumps and not
1092 * the ELF core dump. Each platform can select it as appropriate.
1094 #if defined(USE_ELF_CORE_DUMP) && defined(CONFIG_ELF_CORE)
1097 * ELF core dumper
1099 * Modelled on fs/exec.c:aout_core_dump()
1100 * Jeremy Fitzhardinge <jeremy@sw.oz.au>
1103 * These are the only things you should do on a core-file: use only these
1104 * functions to write out all the necessary info.
1106 static int dump_write(struct file *file, const void *addr, int nr)
1108 return file->f_op->write(file, addr, nr, &file->f_pos) == nr;
1111 static int dump_seek(struct file *file, loff_t off)
1113 if (file->f_op->llseek && file->f_op->llseek != no_llseek) {
1114 if (file->f_op->llseek(file, off, SEEK_CUR) < 0)
1115 return 0;
1116 } else {
1117 char *buf = (char *)get_zeroed_page(GFP_KERNEL);
1118 if (!buf)
1119 return 0;
1120 while (off > 0) {
1121 unsigned long n = off;
1122 if (n > PAGE_SIZE)
1123 n = PAGE_SIZE;
1124 if (!dump_write(file, buf, n))
1125 return 0;
1126 off -= n;
1128 free_page((unsigned long)buf);
1130 return 1;
1134 * Decide what to dump of a segment, part, all or none.
1136 static unsigned long vma_dump_size(struct vm_area_struct *vma,
1137 unsigned long mm_flags)
1139 /* The vma can be set up to tell us the answer directly. */
1140 if (vma->vm_flags & VM_ALWAYSDUMP)
1141 goto whole;
1143 /* Do not dump I/O mapped devices or special mappings */
1144 if (vma->vm_flags & (VM_IO | VM_RESERVED))
1145 return 0;
1147 #define FILTER(type) (mm_flags & (1UL << MMF_DUMP_##type))
1149 /* By default, dump shared memory if mapped from an anonymous file. */
1150 if (vma->vm_flags & VM_SHARED) {
1151 if (vma->vm_file->f_path.dentry->d_inode->i_nlink == 0 ?
1152 FILTER(ANON_SHARED) : FILTER(MAPPED_SHARED))
1153 goto whole;
1154 return 0;
1157 /* Dump segments that have been written to. */
1158 if (vma->anon_vma && FILTER(ANON_PRIVATE))
1159 goto whole;
1160 if (vma->vm_file == NULL)
1161 return 0;
1163 if (FILTER(MAPPED_PRIVATE))
1164 goto whole;
1167 * If this looks like the beginning of a DSO or executable mapping,
1168 * check for an ELF header. If we find one, dump the first page to
1169 * aid in determining what was mapped here.
1171 if (FILTER(ELF_HEADERS) && vma->vm_file != NULL && vma->vm_pgoff == 0) {
1172 u32 __user *header = (u32 __user *) vma->vm_start;
1173 u32 word;
1175 * Doing it this way gets the constant folded by GCC.
1177 union {
1178 u32 cmp;
1179 char elfmag[SELFMAG];
1180 } magic;
1181 BUILD_BUG_ON(SELFMAG != sizeof word);
1182 magic.elfmag[EI_MAG0] = ELFMAG0;
1183 magic.elfmag[EI_MAG1] = ELFMAG1;
1184 magic.elfmag[EI_MAG2] = ELFMAG2;
1185 magic.elfmag[EI_MAG3] = ELFMAG3;
1186 if (get_user(word, header) == 0 && word == magic.cmp)
1187 return PAGE_SIZE;
1190 #undef FILTER
1192 return 0;
1194 whole:
1195 return vma->vm_end - vma->vm_start;
1198 /* An ELF note in memory */
1199 struct memelfnote
1201 const char *name;
1202 int type;
1203 unsigned int datasz;
1204 void *data;
1207 static int notesize(struct memelfnote *en)
1209 int sz;
1211 sz = sizeof(struct elf_note);
1212 sz += roundup(strlen(en->name) + 1, 4);
1213 sz += roundup(en->datasz, 4);
1215 return sz;
1218 #define DUMP_WRITE(addr, nr, foffset) \
1219 do { if (!dump_write(file, (addr), (nr))) return 0; *foffset += (nr); } while(0)
1221 static int alignfile(struct file *file, loff_t *foffset)
1223 static const char buf[4] = { 0, };
1224 DUMP_WRITE(buf, roundup(*foffset, 4) - *foffset, foffset);
1225 return 1;
1228 static int writenote(struct memelfnote *men, struct file *file,
1229 loff_t *foffset)
1231 struct elf_note en;
1232 en.n_namesz = strlen(men->name) + 1;
1233 en.n_descsz = men->datasz;
1234 en.n_type = men->type;
1236 DUMP_WRITE(&en, sizeof(en), foffset);
1237 DUMP_WRITE(men->name, en.n_namesz, foffset);
1238 if (!alignfile(file, foffset))
1239 return 0;
1240 DUMP_WRITE(men->data, men->datasz, foffset);
1241 if (!alignfile(file, foffset))
1242 return 0;
1244 return 1;
1246 #undef DUMP_WRITE
1248 #define DUMP_WRITE(addr, nr) \
1249 if ((size += (nr)) > limit || !dump_write(file, (addr), (nr))) \
1250 goto end_coredump;
1251 #define DUMP_SEEK(off) \
1252 if (!dump_seek(file, (off))) \
1253 goto end_coredump;
1255 static void fill_elf_header(struct elfhdr *elf, int segs,
1256 u16 machine, u32 flags, u8 osabi)
1258 memset(elf, 0, sizeof(*elf));
1260 memcpy(elf->e_ident, ELFMAG, SELFMAG);
1261 elf->e_ident[EI_CLASS] = ELF_CLASS;
1262 elf->e_ident[EI_DATA] = ELF_DATA;
1263 elf->e_ident[EI_VERSION] = EV_CURRENT;
1264 elf->e_ident[EI_OSABI] = ELF_OSABI;
1266 elf->e_type = ET_CORE;
1267 elf->e_machine = machine;
1268 elf->e_version = EV_CURRENT;
1269 elf->e_phoff = sizeof(struct elfhdr);
1270 elf->e_flags = flags;
1271 elf->e_ehsize = sizeof(struct elfhdr);
1272 elf->e_phentsize = sizeof(struct elf_phdr);
1273 elf->e_phnum = segs;
1275 return;
1278 static void fill_elf_note_phdr(struct elf_phdr *phdr, int sz, loff_t offset)
1280 phdr->p_type = PT_NOTE;
1281 phdr->p_offset = offset;
1282 phdr->p_vaddr = 0;
1283 phdr->p_paddr = 0;
1284 phdr->p_filesz = sz;
1285 phdr->p_memsz = 0;
1286 phdr->p_flags = 0;
1287 phdr->p_align = 0;
1288 return;
1291 static void fill_note(struct memelfnote *note, const char *name, int type,
1292 unsigned int sz, void *data)
1294 note->name = name;
1295 note->type = type;
1296 note->datasz = sz;
1297 note->data = data;
1298 return;
1302 * fill up all the fields in prstatus from the given task struct, except
1303 * registers which need to be filled up separately.
1305 static void fill_prstatus(struct elf_prstatus *prstatus,
1306 struct task_struct *p, long signr)
1308 prstatus->pr_info.si_signo = prstatus->pr_cursig = signr;
1309 prstatus->pr_sigpend = p->pending.signal.sig[0];
1310 prstatus->pr_sighold = p->blocked.sig[0];
1311 prstatus->pr_pid = task_pid_vnr(p);
1312 prstatus->pr_ppid = task_pid_vnr(p->real_parent);
1313 prstatus->pr_pgrp = task_pgrp_vnr(p);
1314 prstatus->pr_sid = task_session_vnr(p);
1315 if (thread_group_leader(p)) {
1317 * This is the record for the group leader. Add in the
1318 * cumulative times of previous dead threads. This total
1319 * won't include the time of each live thread whose state
1320 * is included in the core dump. The final total reported
1321 * to our parent process when it calls wait4 will include
1322 * those sums as well as the little bit more time it takes
1323 * this and each other thread to finish dying after the
1324 * core dump synchronization phase.
1326 cputime_to_timeval(cputime_add(p->utime, p->signal->utime),
1327 &prstatus->pr_utime);
1328 cputime_to_timeval(cputime_add(p->stime, p->signal->stime),
1329 &prstatus->pr_stime);
1330 } else {
1331 cputime_to_timeval(p->utime, &prstatus->pr_utime);
1332 cputime_to_timeval(p->stime, &prstatus->pr_stime);
1334 cputime_to_timeval(p->signal->cutime, &prstatus->pr_cutime);
1335 cputime_to_timeval(p->signal->cstime, &prstatus->pr_cstime);
1338 static int fill_psinfo(struct elf_prpsinfo *psinfo, struct task_struct *p,
1339 struct mm_struct *mm)
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 psinfo->pr_pid = task_pid_vnr(p);
1358 psinfo->pr_ppid = task_pid_vnr(p->real_parent);
1359 psinfo->pr_pgrp = task_pgrp_vnr(p);
1360 psinfo->pr_sid = task_session_vnr(p);
1362 i = p->state ? ffz(~p->state) + 1 : 0;
1363 psinfo->pr_state = i;
1364 psinfo->pr_sname = (i > 5) ? '.' : "RSDTZW"[i];
1365 psinfo->pr_zomb = psinfo->pr_sname == 'Z';
1366 psinfo->pr_nice = task_nice(p);
1367 psinfo->pr_flag = p->flags;
1368 SET_UID(psinfo->pr_uid, p->uid);
1369 SET_GID(psinfo->pr_gid, p->gid);
1370 strncpy(psinfo->pr_fname, p->comm, sizeof(psinfo->pr_fname));
1372 return 0;
1375 static void fill_auxv_note(struct memelfnote *note, struct mm_struct *mm)
1377 elf_addr_t *auxv = (elf_addr_t *) mm->saved_auxv;
1378 int i = 0;
1380 i += 2;
1381 while (auxv[i - 2] != AT_NULL);
1382 fill_note(note, "CORE", NT_AUXV, i * sizeof(elf_addr_t), auxv);
1385 #ifdef CORE_DUMP_USE_REGSET
1386 #include <linux/regset.h>
1388 struct elf_thread_core_info {
1389 struct elf_thread_core_info *next;
1390 struct task_struct *task;
1391 struct elf_prstatus prstatus;
1392 struct memelfnote notes[0];
1395 struct elf_note_info {
1396 struct elf_thread_core_info *thread;
1397 struct memelfnote psinfo;
1398 struct memelfnote auxv;
1399 size_t size;
1400 int thread_notes;
1404 * When a regset has a writeback hook, we call it on each thread before
1405 * dumping user memory. On register window machines, this makes sure the
1406 * user memory backing the register data is up to date before we read it.
1408 static void do_thread_regset_writeback(struct task_struct *task,
1409 const struct user_regset *regset)
1411 if (regset->writeback)
1412 regset->writeback(task, regset, 1);
1415 static int fill_thread_core_info(struct elf_thread_core_info *t,
1416 const struct user_regset_view *view,
1417 long signr, size_t *total)
1419 unsigned int i;
1422 * NT_PRSTATUS is the one special case, because the regset data
1423 * goes into the pr_reg field inside the note contents, rather
1424 * than being the whole note contents. We fill the reset in here.
1425 * We assume that regset 0 is NT_PRSTATUS.
1427 fill_prstatus(&t->prstatus, t->task, signr);
1428 (void) view->regsets[0].get(t->task, &view->regsets[0],
1429 0, sizeof(t->prstatus.pr_reg),
1430 &t->prstatus.pr_reg, NULL);
1432 fill_note(&t->notes[0], "CORE", NT_PRSTATUS,
1433 sizeof(t->prstatus), &t->prstatus);
1434 *total += notesize(&t->notes[0]);
1436 do_thread_regset_writeback(t->task, &view->regsets[0]);
1439 * Each other regset might generate a note too. For each regset
1440 * that has no core_note_type or is inactive, we leave t->notes[i]
1441 * all zero and we'll know to skip writing it later.
1443 for (i = 1; i < view->n; ++i) {
1444 const struct user_regset *regset = &view->regsets[i];
1445 do_thread_regset_writeback(t->task, regset);
1446 if (regset->core_note_type &&
1447 (!regset->active || regset->active(t->task, regset))) {
1448 int ret;
1449 size_t size = regset->n * regset->size;
1450 void *data = kmalloc(size, GFP_KERNEL);
1451 if (unlikely(!data))
1452 return 0;
1453 ret = regset->get(t->task, regset,
1454 0, size, data, NULL);
1455 if (unlikely(ret))
1456 kfree(data);
1457 else {
1458 if (regset->core_note_type != NT_PRFPREG)
1459 fill_note(&t->notes[i], "LINUX",
1460 regset->core_note_type,
1461 size, data);
1462 else {
1463 t->prstatus.pr_fpvalid = 1;
1464 fill_note(&t->notes[i], "CORE",
1465 NT_PRFPREG, size, data);
1467 *total += notesize(&t->notes[i]);
1472 return 1;
1475 static int fill_note_info(struct elfhdr *elf, int phdrs,
1476 struct elf_note_info *info,
1477 long signr, struct pt_regs *regs)
1479 struct task_struct *dump_task = current;
1480 const struct user_regset_view *view = task_user_regset_view(dump_task);
1481 struct elf_thread_core_info *t;
1482 struct elf_prpsinfo *psinfo;
1483 struct task_struct *g, *p;
1484 unsigned int i;
1486 info->size = 0;
1487 info->thread = NULL;
1489 psinfo = kmalloc(sizeof(*psinfo), GFP_KERNEL);
1490 fill_note(&info->psinfo, "CORE", NT_PRPSINFO, sizeof(*psinfo), psinfo);
1492 if (psinfo == NULL)
1493 return 0;
1496 * Figure out how many notes we're going to need for each thread.
1498 info->thread_notes = 0;
1499 for (i = 0; i < view->n; ++i)
1500 if (view->regsets[i].core_note_type != 0)
1501 ++info->thread_notes;
1504 * Sanity check. We rely on regset 0 being in NT_PRSTATUS,
1505 * since it is our one special case.
1507 if (unlikely(info->thread_notes == 0) ||
1508 unlikely(view->regsets[0].core_note_type != NT_PRSTATUS)) {
1509 WARN_ON(1);
1510 return 0;
1514 * Initialize the ELF file header.
1516 fill_elf_header(elf, phdrs,
1517 view->e_machine, view->e_flags, view->ei_osabi);
1520 * Allocate a structure for each thread.
1522 rcu_read_lock();
1523 do_each_thread(g, p)
1524 if (p->mm == dump_task->mm) {
1525 t = kzalloc(offsetof(struct elf_thread_core_info,
1526 notes[info->thread_notes]),
1527 GFP_ATOMIC);
1528 if (unlikely(!t)) {
1529 rcu_read_unlock();
1530 return 0;
1532 t->task = p;
1533 if (p == dump_task || !info->thread) {
1534 t->next = info->thread;
1535 info->thread = t;
1536 } else {
1538 * Make sure to keep the original task at
1539 * the head of the list.
1541 t->next = info->thread->next;
1542 info->thread->next = t;
1545 while_each_thread(g, p);
1546 rcu_read_unlock();
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 fill_note_info(struct elfhdr *elf, int phdrs,
1688 struct elf_note_info *info,
1689 long signr, struct pt_regs *regs)
1691 #define NUM_NOTES 6
1692 struct list_head *t;
1693 struct task_struct *g, *p;
1695 info->notes = NULL;
1696 info->prstatus = NULL;
1697 info->psinfo = NULL;
1698 info->fpu = NULL;
1699 #ifdef ELF_CORE_COPY_XFPREGS
1700 info->xfpu = NULL;
1701 #endif
1702 INIT_LIST_HEAD(&info->thread_list);
1704 info->notes = kmalloc(NUM_NOTES * sizeof(struct memelfnote),
1705 GFP_KERNEL);
1706 if (!info->notes)
1707 return 0;
1708 info->psinfo = kmalloc(sizeof(*info->psinfo), GFP_KERNEL);
1709 if (!info->psinfo)
1710 return 0;
1711 info->prstatus = kmalloc(sizeof(*info->prstatus), GFP_KERNEL);
1712 if (!info->prstatus)
1713 return 0;
1714 info->fpu = kmalloc(sizeof(*info->fpu), GFP_KERNEL);
1715 if (!info->fpu)
1716 return 0;
1717 #ifdef ELF_CORE_COPY_XFPREGS
1718 info->xfpu = kmalloc(sizeof(*info->xfpu), GFP_KERNEL);
1719 if (!info->xfpu)
1720 return 0;
1721 #endif
1723 info->thread_status_size = 0;
1724 if (signr) {
1725 struct elf_thread_status *ets;
1726 rcu_read_lock();
1727 do_each_thread(g, p)
1728 if (current->mm == p->mm && current != p) {
1729 ets = kzalloc(sizeof(*ets), GFP_ATOMIC);
1730 if (!ets) {
1731 rcu_read_unlock();
1732 return 0;
1734 ets->thread = p;
1735 list_add(&ets->list, &info->thread_list);
1737 while_each_thread(g, p);
1738 rcu_read_unlock();
1739 list_for_each(t, &info->thread_list) {
1740 int sz;
1742 ets = list_entry(t, struct elf_thread_status, list);
1743 sz = elf_dump_thread_status(signr, ets);
1744 info->thread_status_size += sz;
1747 /* now collect the dump for the current */
1748 memset(info->prstatus, 0, sizeof(*info->prstatus));
1749 fill_prstatus(info->prstatus, current, signr);
1750 elf_core_copy_regs(&info->prstatus->pr_reg, regs);
1752 /* Set up header */
1753 fill_elf_header(elf, phdrs, ELF_ARCH, ELF_CORE_EFLAGS, ELF_OSABI);
1756 * Set up the notes in similar form to SVR4 core dumps made
1757 * with info from their /proc.
1760 fill_note(info->notes + 0, "CORE", NT_PRSTATUS,
1761 sizeof(*info->prstatus), info->prstatus);
1762 fill_psinfo(info->psinfo, current->group_leader, current->mm);
1763 fill_note(info->notes + 1, "CORE", NT_PRPSINFO,
1764 sizeof(*info->psinfo), info->psinfo);
1766 info->numnote = 2;
1768 fill_auxv_note(&info->notes[info->numnote++], current->mm);
1770 /* Try to dump the FPU. */
1771 info->prstatus->pr_fpvalid = elf_core_copy_task_fpregs(current, regs,
1772 info->fpu);
1773 if (info->prstatus->pr_fpvalid)
1774 fill_note(info->notes + info->numnote++,
1775 "CORE", NT_PRFPREG, sizeof(*info->fpu), info->fpu);
1776 #ifdef ELF_CORE_COPY_XFPREGS
1777 if (elf_core_copy_task_xfpregs(current, info->xfpu))
1778 fill_note(info->notes + info->numnote++,
1779 "LINUX", ELF_CORE_XFPREG_TYPE,
1780 sizeof(*info->xfpu), info->xfpu);
1781 #endif
1783 return 1;
1785 #undef NUM_NOTES
1788 static size_t get_note_info_size(struct elf_note_info *info)
1790 int sz = 0;
1791 int i;
1793 for (i = 0; i < info->numnote; i++)
1794 sz += notesize(info->notes + i);
1796 sz += info->thread_status_size;
1798 return sz;
1801 static int write_note_info(struct elf_note_info *info,
1802 struct file *file, loff_t *foffset)
1804 int i;
1805 struct list_head *t;
1807 for (i = 0; i < info->numnote; i++)
1808 if (!writenote(info->notes + i, file, foffset))
1809 return 0;
1811 /* write out the thread status notes section */
1812 list_for_each(t, &info->thread_list) {
1813 struct elf_thread_status *tmp =
1814 list_entry(t, struct elf_thread_status, list);
1816 for (i = 0; i < tmp->num_notes; i++)
1817 if (!writenote(&tmp->notes[i], file, foffset))
1818 return 0;
1821 return 1;
1824 static void free_note_info(struct elf_note_info *info)
1826 while (!list_empty(&info->thread_list)) {
1827 struct list_head *tmp = info->thread_list.next;
1828 list_del(tmp);
1829 kfree(list_entry(tmp, struct elf_thread_status, list));
1832 kfree(info->prstatus);
1833 kfree(info->psinfo);
1834 kfree(info->notes);
1835 kfree(info->fpu);
1836 #ifdef ELF_CORE_COPY_XFPREGS
1837 kfree(info->xfpu);
1838 #endif
1841 #endif
1843 static struct vm_area_struct *first_vma(struct task_struct *tsk,
1844 struct vm_area_struct *gate_vma)
1846 struct vm_area_struct *ret = tsk->mm->mmap;
1848 if (ret)
1849 return ret;
1850 return gate_vma;
1853 * Helper function for iterating across a vma list. It ensures that the caller
1854 * will visit `gate_vma' prior to terminating the search.
1856 static struct vm_area_struct *next_vma(struct vm_area_struct *this_vma,
1857 struct vm_area_struct *gate_vma)
1859 struct vm_area_struct *ret;
1861 ret = this_vma->vm_next;
1862 if (ret)
1863 return ret;
1864 if (this_vma == gate_vma)
1865 return NULL;
1866 return gate_vma;
1870 * Actual dumper
1872 * This is a two-pass process; first we find the offsets of the bits,
1873 * and then they are actually written out. If we run out of core limit
1874 * we just truncate.
1876 static int elf_core_dump(long signr, struct pt_regs *regs, struct file *file, unsigned long limit)
1878 int has_dumped = 0;
1879 mm_segment_t fs;
1880 int segs;
1881 size_t size = 0;
1882 struct vm_area_struct *vma, *gate_vma;
1883 struct elfhdr *elf = NULL;
1884 loff_t offset = 0, dataoff, foffset;
1885 unsigned long mm_flags;
1886 struct elf_note_info info;
1889 * We no longer stop all VM operations.
1891 * This is because those proceses that could possibly change map_count
1892 * or the mmap / vma pages are now blocked in do_exit on current
1893 * finishing this core dump.
1895 * Only ptrace can touch these memory addresses, but it doesn't change
1896 * the map_count or the pages allocated. So no possibility of crashing
1897 * exists while dumping the mm->vm_next areas to the core file.
1900 /* alloc memory for large data structures: too large to be on stack */
1901 elf = kmalloc(sizeof(*elf), GFP_KERNEL);
1902 if (!elf)
1903 goto out;
1905 segs = current->mm->map_count;
1906 #ifdef ELF_CORE_EXTRA_PHDRS
1907 segs += ELF_CORE_EXTRA_PHDRS;
1908 #endif
1910 gate_vma = get_gate_vma(current);
1911 if (gate_vma != NULL)
1912 segs++;
1915 * Collect all the non-memory information about the process for the
1916 * notes. This also sets up the file header.
1918 if (!fill_note_info(elf, segs + 1, /* including notes section */
1919 &info, signr, regs))
1920 goto cleanup;
1922 has_dumped = 1;
1923 current->flags |= PF_DUMPCORE;
1925 fs = get_fs();
1926 set_fs(KERNEL_DS);
1928 DUMP_WRITE(elf, sizeof(*elf));
1929 offset += sizeof(*elf); /* Elf header */
1930 offset += (segs + 1) * sizeof(struct elf_phdr); /* Program headers */
1931 foffset = offset;
1933 /* Write notes phdr entry */
1935 struct elf_phdr phdr;
1936 size_t sz = get_note_info_size(&info);
1938 sz += elf_coredump_extra_notes_size();
1940 fill_elf_note_phdr(&phdr, sz, offset);
1941 offset += sz;
1942 DUMP_WRITE(&phdr, sizeof(phdr));
1945 dataoff = offset = roundup(offset, ELF_EXEC_PAGESIZE);
1948 * We must use the same mm->flags while dumping core to avoid
1949 * inconsistency between the program headers and bodies, otherwise an
1950 * unusable core file can be generated.
1952 mm_flags = current->mm->flags;
1954 /* Write program headers for segments dump */
1955 for (vma = first_vma(current, gate_vma); vma != NULL;
1956 vma = next_vma(vma, gate_vma)) {
1957 struct elf_phdr phdr;
1959 phdr.p_type = PT_LOAD;
1960 phdr.p_offset = offset;
1961 phdr.p_vaddr = vma->vm_start;
1962 phdr.p_paddr = 0;
1963 phdr.p_filesz = vma_dump_size(vma, mm_flags);
1964 phdr.p_memsz = vma->vm_end - vma->vm_start;
1965 offset += phdr.p_filesz;
1966 phdr.p_flags = vma->vm_flags & VM_READ ? PF_R : 0;
1967 if (vma->vm_flags & VM_WRITE)
1968 phdr.p_flags |= PF_W;
1969 if (vma->vm_flags & VM_EXEC)
1970 phdr.p_flags |= PF_X;
1971 phdr.p_align = ELF_EXEC_PAGESIZE;
1973 DUMP_WRITE(&phdr, sizeof(phdr));
1976 #ifdef ELF_CORE_WRITE_EXTRA_PHDRS
1977 ELF_CORE_WRITE_EXTRA_PHDRS;
1978 #endif
1980 /* write out the notes section */
1981 if (!write_note_info(&info, file, &foffset))
1982 goto end_coredump;
1984 if (elf_coredump_extra_notes_write(file, &foffset))
1985 goto end_coredump;
1987 /* Align to page */
1988 DUMP_SEEK(dataoff - foffset);
1990 for (vma = first_vma(current, gate_vma); vma != NULL;
1991 vma = next_vma(vma, gate_vma)) {
1992 unsigned long addr;
1993 unsigned long end;
1995 end = vma->vm_start + vma_dump_size(vma, mm_flags);
1997 for (addr = vma->vm_start; addr < end; addr += PAGE_SIZE) {
1998 struct page *page;
1999 struct vm_area_struct *tmp_vma;
2001 if (get_user_pages(current, current->mm, addr, 1, 0, 1,
2002 &page, &tmp_vma) <= 0) {
2003 DUMP_SEEK(PAGE_SIZE);
2004 } else {
2005 if (page == ZERO_PAGE(0)) {
2006 if (!dump_seek(file, PAGE_SIZE)) {
2007 page_cache_release(page);
2008 goto end_coredump;
2010 } else {
2011 void *kaddr;
2012 flush_cache_page(tmp_vma, addr,
2013 page_to_pfn(page));
2014 kaddr = kmap(page);
2015 if ((size += PAGE_SIZE) > limit ||
2016 !dump_write(file, kaddr,
2017 PAGE_SIZE)) {
2018 kunmap(page);
2019 page_cache_release(page);
2020 goto end_coredump;
2022 kunmap(page);
2024 page_cache_release(page);
2029 #ifdef ELF_CORE_WRITE_EXTRA_DATA
2030 ELF_CORE_WRITE_EXTRA_DATA;
2031 #endif
2033 end_coredump:
2034 set_fs(fs);
2036 cleanup:
2037 free_note_info(&info);
2038 kfree(elf);
2039 out:
2040 return has_dumped;
2043 #endif /* USE_ELF_CORE_DUMP */
2045 static int __init init_elf_binfmt(void)
2047 return register_binfmt(&elf_format);
2050 static void __exit exit_elf_binfmt(void)
2052 /* Remove the COFF and ELF loaders. */
2053 unregister_binfmt(&elf_format);
2056 core_initcall(init_elf_binfmt);
2057 module_exit(exit_elf_binfmt);
2058 MODULE_LICENSE("GPL");