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
9 * Copyright 1993, 1994: Eric Youngdale (ericy@cais.com).
12 #include <linux/module.h>
13 #include <linux/kernel.h>
16 #include <linux/mman.h>
17 #include <linux/errno.h>
18 #include <linux/signal.h>
19 #include <linux/binfmts.h>
20 #include <linux/string.h>
21 #include <linux/file.h>
22 #include <linux/slab.h>
23 #include <linux/personality.h>
24 #include <linux/elfcore.h>
25 #include <linux/init.h>
26 #include <linux/highuid.h>
27 #include <linux/compiler.h>
28 #include <linux/highmem.h>
29 #include <linux/pagemap.h>
30 #include <linux/security.h>
31 #include <linux/random.h>
32 #include <linux/elf.h>
33 #include <linux/utsname.h>
34 #include <linux/coredump.h>
35 #include <asm/uaccess.h>
36 #include <asm/param.h>
39 static int load_elf_binary(struct linux_binprm *bprm, struct pt_regs *regs);
40 static int load_elf_library(struct file *);
41 static unsigned long elf_map(struct file *, unsigned long, struct elf_phdr *,
42 int, int, unsigned long);
45 * If we don't support core dumping, then supply a NULL so we
48 #ifdef CONFIG_ELF_CORE
49 static int elf_core_dump(struct coredump_params *cprm);
51 #define elf_core_dump NULL
54 #if ELF_EXEC_PAGESIZE > PAGE_SIZE
55 #define ELF_MIN_ALIGN ELF_EXEC_PAGESIZE
57 #define ELF_MIN_ALIGN PAGE_SIZE
60 #ifndef ELF_CORE_EFLAGS
61 #define ELF_CORE_EFLAGS 0
64 #define ELF_PAGESTART(_v) ((_v) & ~(unsigned long)(ELF_MIN_ALIGN-1))
65 #define ELF_PAGEOFFSET(_v) ((_v) & (ELF_MIN_ALIGN-1))
66 #define ELF_PAGEALIGN(_v) (((_v) + ELF_MIN_ALIGN - 1) & ~(ELF_MIN_ALIGN - 1))
68 static struct linux_binfmt elf_format = {
69 .module = THIS_MODULE,
70 .load_binary = load_elf_binary,
71 .load_shlib = load_elf_library,
72 .core_dump = elf_core_dump,
73 .min_coredump = ELF_EXEC_PAGESIZE,
76 #define BAD_ADDR(x) ((unsigned long)(x) >= TASK_SIZE)
78 static int set_brk(unsigned long start, unsigned long end)
80 start = ELF_PAGEALIGN(start);
81 end = ELF_PAGEALIGN(end);
84 down_write(¤t->mm->mmap_sem);
85 addr = do_brk(start, end - start);
86 up_write(¤t->mm->mmap_sem);
90 current->mm->start_brk = current->mm->brk = end;
94 /* We need to explicitly zero any fractional pages
95 after the data section (i.e. bss). This would
96 contain the junk from the file that should not
99 static int padzero(unsigned long elf_bss)
103 nbyte = ELF_PAGEOFFSET(elf_bss);
105 nbyte = ELF_MIN_ALIGN - nbyte;
106 if (clear_user((void __user *) elf_bss, nbyte))
112 /* Let's use some macros to make this stack manipulation a little clearer */
113 #ifdef CONFIG_STACK_GROWSUP
114 #define STACK_ADD(sp, items) ((elf_addr_t __user *)(sp) + (items))
115 #define STACK_ROUND(sp, items) \
116 ((15 + (unsigned long) ((sp) + (items))) &~ 15UL)
117 #define STACK_ALLOC(sp, len) ({ \
118 elf_addr_t __user *old_sp = (elf_addr_t __user *)sp; sp += len; \
121 #define STACK_ADD(sp, items) ((elf_addr_t __user *)(sp) - (items))
122 #define STACK_ROUND(sp, items) \
123 (((unsigned long) (sp - items)) &~ 15UL)
124 #define STACK_ALLOC(sp, len) ({ sp -= len ; sp; })
127 #ifndef ELF_BASE_PLATFORM
129 * AT_BASE_PLATFORM indicates the "real" hardware/microarchitecture.
130 * If the arch defines ELF_BASE_PLATFORM (in asm/elf.h), the value
131 * will be copied to the user stack in the same manner as AT_PLATFORM.
133 #define ELF_BASE_PLATFORM NULL
137 create_elf_tables(struct linux_binprm *bprm, struct elfhdr *exec,
138 unsigned long load_addr, unsigned long interp_load_addr)
140 unsigned long p = bprm->p;
141 int argc = bprm->argc;
142 int envc = bprm->envc;
143 elf_addr_t __user *argv;
144 elf_addr_t __user *envp;
145 elf_addr_t __user *sp;
146 elf_addr_t __user *u_platform;
147 elf_addr_t __user *u_base_platform;
148 elf_addr_t __user *u_rand_bytes;
149 const char *k_platform = ELF_PLATFORM;
150 const char *k_base_platform = ELF_BASE_PLATFORM;
151 unsigned char k_rand_bytes[16];
153 elf_addr_t *elf_info;
155 const struct cred *cred = current_cred();
156 struct vm_area_struct *vma;
159 * In some cases (e.g. Hyper-Threading), we want to avoid L1
160 * evictions by the processes running on the same package. One
161 * thing we can do is to shuffle the initial stack for them.
164 p = arch_align_stack(p);
167 * If this architecture has a platform capability string, copy it
168 * to userspace. In some cases (Sparc), this info is impossible
169 * for userspace to get any other way, in others (i386) it is
174 size_t len = strlen(k_platform) + 1;
176 u_platform = (elf_addr_t __user *)STACK_ALLOC(p, len);
177 if (__copy_to_user(u_platform, k_platform, len))
182 * If this architecture has a "base" platform capability
183 * string, copy it to userspace.
185 u_base_platform = NULL;
186 if (k_base_platform) {
187 size_t len = strlen(k_base_platform) + 1;
189 u_base_platform = (elf_addr_t __user *)STACK_ALLOC(p, len);
190 if (__copy_to_user(u_base_platform, k_base_platform, len))
195 * Generate 16 random bytes for userspace PRNG seeding.
197 get_random_bytes(k_rand_bytes, sizeof(k_rand_bytes));
198 u_rand_bytes = (elf_addr_t __user *)
199 STACK_ALLOC(p, sizeof(k_rand_bytes));
200 if (__copy_to_user(u_rand_bytes, k_rand_bytes, sizeof(k_rand_bytes)))
203 /* Create the ELF interpreter info */
204 elf_info = (elf_addr_t *)current->mm->saved_auxv;
205 /* update AT_VECTOR_SIZE_BASE if the number of NEW_AUX_ENT() changes */
206 #define NEW_AUX_ENT(id, val) \
208 elf_info[ei_index++] = id; \
209 elf_info[ei_index++] = val; \
214 * ARCH_DLINFO must come first so PPC can do its special alignment of
216 * update AT_VECTOR_SIZE_ARCH if the number of NEW_AUX_ENT() in
217 * ARCH_DLINFO changes
221 NEW_AUX_ENT(AT_HWCAP, ELF_HWCAP);
222 NEW_AUX_ENT(AT_PAGESZ, ELF_EXEC_PAGESIZE);
223 NEW_AUX_ENT(AT_CLKTCK, CLOCKS_PER_SEC);
224 NEW_AUX_ENT(AT_PHDR, load_addr + exec->e_phoff);
225 NEW_AUX_ENT(AT_PHENT, sizeof(struct elf_phdr));
226 NEW_AUX_ENT(AT_PHNUM, exec->e_phnum);
227 NEW_AUX_ENT(AT_BASE, interp_load_addr);
228 NEW_AUX_ENT(AT_FLAGS, 0);
229 NEW_AUX_ENT(AT_ENTRY, exec->e_entry);
230 NEW_AUX_ENT(AT_UID, cred->uid);
231 NEW_AUX_ENT(AT_EUID, cred->euid);
232 NEW_AUX_ENT(AT_GID, cred->gid);
233 NEW_AUX_ENT(AT_EGID, cred->egid);
234 NEW_AUX_ENT(AT_SECURE, security_bprm_secureexec(bprm));
235 NEW_AUX_ENT(AT_RANDOM, (elf_addr_t)(unsigned long)u_rand_bytes);
236 NEW_AUX_ENT(AT_EXECFN, bprm->exec);
238 NEW_AUX_ENT(AT_PLATFORM,
239 (elf_addr_t)(unsigned long)u_platform);
241 if (k_base_platform) {
242 NEW_AUX_ENT(AT_BASE_PLATFORM,
243 (elf_addr_t)(unsigned long)u_base_platform);
245 if (bprm->interp_flags & BINPRM_FLAGS_EXECFD) {
246 NEW_AUX_ENT(AT_EXECFD, bprm->interp_data);
249 /* AT_NULL is zero; clear the rest too */
250 memset(&elf_info[ei_index], 0,
251 sizeof current->mm->saved_auxv - ei_index * sizeof elf_info[0]);
253 /* And advance past the AT_NULL entry. */
256 sp = STACK_ADD(p, ei_index);
258 items = (argc + 1) + (envc + 1) + 1;
259 bprm->p = STACK_ROUND(sp, items);
261 /* Point sp at the lowest address on the stack */
262 #ifdef CONFIG_STACK_GROWSUP
263 sp = (elf_addr_t __user *)bprm->p - items - ei_index;
264 bprm->exec = (unsigned long)sp; /* XXX: PARISC HACK */
266 sp = (elf_addr_t __user *)bprm->p;
271 * Grow the stack manually; some architectures have a limit on how
272 * far ahead a user-space access may be in order to grow the stack.
274 vma = find_extend_vma(current->mm, bprm->p);
278 /* Now, let's put argc (and argv, envp if appropriate) on the stack */
279 if (__put_user(argc, sp++))
282 envp = argv + argc + 1;
284 /* Populate argv and envp */
285 p = current->mm->arg_end = current->mm->arg_start;
288 if (__put_user((elf_addr_t)p, argv++))
290 len = strnlen_user((void __user *)p, MAX_ARG_STRLEN);
291 if (!len || len > MAX_ARG_STRLEN)
295 if (__put_user(0, argv))
297 current->mm->arg_end = current->mm->env_start = p;
300 if (__put_user((elf_addr_t)p, envp++))
302 len = strnlen_user((void __user *)p, MAX_ARG_STRLEN);
303 if (!len || len > MAX_ARG_STRLEN)
307 if (__put_user(0, envp))
309 current->mm->env_end = p;
311 /* Put the elf_info on the stack in the right place. */
312 sp = (elf_addr_t __user *)envp + 1;
313 if (copy_to_user(sp, elf_info, ei_index * sizeof(elf_addr_t)))
318 static unsigned long elf_map(struct file *filep, unsigned long addr,
319 struct elf_phdr *eppnt, int prot, int type,
320 unsigned long total_size)
322 unsigned long map_addr;
323 unsigned long size = eppnt->p_filesz + ELF_PAGEOFFSET(eppnt->p_vaddr);
324 unsigned long off = eppnt->p_offset - ELF_PAGEOFFSET(eppnt->p_vaddr);
325 addr = ELF_PAGESTART(addr);
326 size = ELF_PAGEALIGN(size);
328 /* mmap() will return -EINVAL if given a zero size, but a
329 * segment with zero filesize is perfectly valid */
333 down_write(¤t->mm->mmap_sem);
335 * total_size is the size of the ELF (interpreter) image.
336 * The _first_ mmap needs to know the full size, otherwise
337 * randomization might put this image into an overlapping
338 * position with the ELF binary image. (since size < total_size)
339 * So we first map the 'big' image - and unmap the remainder at
340 * the end. (which unmap is needed for ELF images with holes.)
343 total_size = ELF_PAGEALIGN(total_size);
344 map_addr = do_mmap(filep, addr, total_size, prot, type, off);
345 if (!BAD_ADDR(map_addr))
346 do_munmap(current->mm, map_addr+size, total_size-size);
348 map_addr = do_mmap(filep, addr, size, prot, type, off);
350 up_write(¤t->mm->mmap_sem);
354 static unsigned long total_mapping_size(struct elf_phdr *cmds, int nr)
356 int i, first_idx = -1, last_idx = -1;
358 for (i = 0; i < nr; i++) {
359 if (cmds[i].p_type == PT_LOAD) {
368 return cmds[last_idx].p_vaddr + cmds[last_idx].p_memsz -
369 ELF_PAGESTART(cmds[first_idx].p_vaddr);
373 /* This is much more generalized than the library routine read function,
374 so we keep this separate. Technically the library read function
375 is only provided so that we can read a.out libraries that have
378 static unsigned long load_elf_interp(struct elfhdr *interp_elf_ex,
379 struct file *interpreter, unsigned long *interp_map_addr,
380 unsigned long no_base)
382 struct elf_phdr *elf_phdata;
383 struct elf_phdr *eppnt;
384 unsigned long load_addr = 0;
385 int load_addr_set = 0;
386 unsigned long last_bss = 0, elf_bss = 0;
387 unsigned long error = ~0UL;
388 unsigned long total_size;
391 /* First of all, some simple consistency checks */
392 if (interp_elf_ex->e_type != ET_EXEC &&
393 interp_elf_ex->e_type != ET_DYN)
395 if (!elf_check_arch(interp_elf_ex))
397 if (!interpreter->f_op || !interpreter->f_op->mmap)
401 * If the size of this structure has changed, then punt, since
402 * we will be doing the wrong thing.
404 if (interp_elf_ex->e_phentsize != sizeof(struct elf_phdr))
406 if (interp_elf_ex->e_phnum < 1 ||
407 interp_elf_ex->e_phnum > 65536U / sizeof(struct elf_phdr))
410 /* Now read in all of the header information */
411 size = sizeof(struct elf_phdr) * interp_elf_ex->e_phnum;
412 if (size > ELF_MIN_ALIGN)
414 elf_phdata = kmalloc(size, GFP_KERNEL);
418 retval = kernel_read(interpreter, interp_elf_ex->e_phoff,
419 (char *)elf_phdata, size);
421 if (retval != size) {
427 total_size = total_mapping_size(elf_phdata, interp_elf_ex->e_phnum);
434 for (i = 0; i < interp_elf_ex->e_phnum; i++, eppnt++) {
435 if (eppnt->p_type == PT_LOAD) {
436 int elf_type = MAP_PRIVATE | MAP_DENYWRITE;
438 unsigned long vaddr = 0;
439 unsigned long k, map_addr;
441 if (eppnt->p_flags & PF_R)
442 elf_prot = PROT_READ;
443 if (eppnt->p_flags & PF_W)
444 elf_prot |= PROT_WRITE;
445 if (eppnt->p_flags & PF_X)
446 elf_prot |= PROT_EXEC;
447 vaddr = eppnt->p_vaddr;
448 if (interp_elf_ex->e_type == ET_EXEC || load_addr_set)
449 elf_type |= MAP_FIXED;
450 else if (no_base && interp_elf_ex->e_type == ET_DYN)
453 map_addr = elf_map(interpreter, load_addr + vaddr,
454 eppnt, elf_prot, elf_type, total_size);
456 if (!*interp_map_addr)
457 *interp_map_addr = map_addr;
459 if (BAD_ADDR(map_addr))
462 if (!load_addr_set &&
463 interp_elf_ex->e_type == ET_DYN) {
464 load_addr = map_addr - ELF_PAGESTART(vaddr);
469 * Check to see if the section's size will overflow the
470 * allowed task size. Note that p_filesz must always be
471 * <= p_memsize so it's only necessary to check p_memsz.
473 k = load_addr + eppnt->p_vaddr;
475 eppnt->p_filesz > eppnt->p_memsz ||
476 eppnt->p_memsz > TASK_SIZE ||
477 TASK_SIZE - eppnt->p_memsz < k) {
483 * Find the end of the file mapping for this phdr, and
484 * keep track of the largest address we see for this.
486 k = load_addr + eppnt->p_vaddr + eppnt->p_filesz;
491 * Do the same thing for the memory mapping - between
492 * elf_bss and last_bss is the bss section.
494 k = load_addr + eppnt->p_memsz + eppnt->p_vaddr;
500 if (last_bss > elf_bss) {
502 * Now fill out the bss section. First pad the last page up
503 * to the page boundary, and then perform a mmap to make sure
504 * that there are zero-mapped pages up to and including the
507 if (padzero(elf_bss)) {
512 /* What we have mapped so far */
513 elf_bss = ELF_PAGESTART(elf_bss + ELF_MIN_ALIGN - 1);
515 /* Map the last of the bss segment */
516 down_write(¤t->mm->mmap_sem);
517 error = do_brk(elf_bss, last_bss - elf_bss);
518 up_write(¤t->mm->mmap_sem);
532 * These are the functions used to load ELF style executables and shared
533 * libraries. There is no binary dependent code anywhere else.
536 #define INTERPRETER_NONE 0
537 #define INTERPRETER_ELF 2
539 #ifndef STACK_RND_MASK
540 #define STACK_RND_MASK (0x7ff >> (PAGE_SHIFT - 12)) /* 8MB of VA */
543 static unsigned long randomize_stack_top(unsigned long stack_top)
545 unsigned int random_variable = 0;
547 if ((current->flags & PF_RANDOMIZE) &&
548 !(current->personality & ADDR_NO_RANDOMIZE)) {
549 random_variable = get_random_int() & STACK_RND_MASK;
550 random_variable <<= PAGE_SHIFT;
552 #ifdef CONFIG_STACK_GROWSUP
553 return PAGE_ALIGN(stack_top) + random_variable;
555 return PAGE_ALIGN(stack_top) - random_variable;
559 static int load_elf_binary(struct linux_binprm *bprm, struct pt_regs *regs)
561 struct file *interpreter = NULL; /* to shut gcc up */
562 unsigned long load_addr = 0, load_bias = 0;
563 int load_addr_set = 0;
564 char * elf_interpreter = NULL;
566 struct elf_phdr *elf_ppnt, *elf_phdata;
567 unsigned long elf_bss, elf_brk;
570 unsigned long elf_entry;
571 unsigned long interp_load_addr = 0;
572 unsigned long start_code, end_code, start_data, end_data;
573 unsigned long reloc_func_desc __maybe_unused = 0;
574 int executable_stack = EXSTACK_DEFAULT;
575 unsigned long def_flags = 0;
577 struct elfhdr elf_ex;
578 struct elfhdr interp_elf_ex;
581 loc = kmalloc(sizeof(*loc), GFP_KERNEL);
587 /* Get the exec-header */
588 loc->elf_ex = *((struct elfhdr *)bprm->buf);
591 /* First of all, some simple consistency checks */
592 if (memcmp(loc->elf_ex.e_ident, ELFMAG, SELFMAG) != 0)
595 if (loc->elf_ex.e_type != ET_EXEC && loc->elf_ex.e_type != ET_DYN)
597 if (!elf_check_arch(&loc->elf_ex))
599 if (!bprm->file->f_op || !bprm->file->f_op->mmap)
602 /* Now read in all of the header information */
603 if (loc->elf_ex.e_phentsize != sizeof(struct elf_phdr))
605 if (loc->elf_ex.e_phnum < 1 ||
606 loc->elf_ex.e_phnum > 65536U / sizeof(struct elf_phdr))
608 size = loc->elf_ex.e_phnum * sizeof(struct elf_phdr);
610 elf_phdata = kmalloc(size, GFP_KERNEL);
614 retval = kernel_read(bprm->file, loc->elf_ex.e_phoff,
615 (char *)elf_phdata, size);
616 if (retval != size) {
622 elf_ppnt = elf_phdata;
631 for (i = 0; i < loc->elf_ex.e_phnum; i++) {
632 if (elf_ppnt->p_type == PT_INTERP) {
633 /* This is the program interpreter used for
634 * shared libraries - for now assume that this
635 * is an a.out format binary
638 if (elf_ppnt->p_filesz > PATH_MAX ||
639 elf_ppnt->p_filesz < 2)
643 elf_interpreter = kmalloc(elf_ppnt->p_filesz,
645 if (!elf_interpreter)
648 retval = kernel_read(bprm->file, elf_ppnt->p_offset,
651 if (retval != elf_ppnt->p_filesz) {
654 goto out_free_interp;
656 /* make sure path is NULL terminated */
658 if (elf_interpreter[elf_ppnt->p_filesz - 1] != '\0')
659 goto out_free_interp;
661 interpreter = open_exec(elf_interpreter);
662 retval = PTR_ERR(interpreter);
663 if (IS_ERR(interpreter))
664 goto out_free_interp;
667 * If the binary is not readable then enforce
668 * mm->dumpable = 0 regardless of the interpreter's
671 would_dump(bprm, interpreter);
673 retval = kernel_read(interpreter, 0, bprm->buf,
675 if (retval != BINPRM_BUF_SIZE) {
678 goto out_free_dentry;
681 /* Get the exec headers */
682 loc->interp_elf_ex = *((struct elfhdr *)bprm->buf);
688 elf_ppnt = elf_phdata;
689 for (i = 0; i < loc->elf_ex.e_phnum; i++, elf_ppnt++)
690 if (elf_ppnt->p_type == PT_GNU_STACK) {
691 if (elf_ppnt->p_flags & PF_X)
692 executable_stack = EXSTACK_ENABLE_X;
694 executable_stack = EXSTACK_DISABLE_X;
698 /* Some simple consistency checks for the interpreter */
699 if (elf_interpreter) {
701 /* Not an ELF interpreter */
702 if (memcmp(loc->interp_elf_ex.e_ident, ELFMAG, SELFMAG) != 0)
703 goto out_free_dentry;
704 /* Verify the interpreter has a valid arch */
705 if (!elf_check_arch(&loc->interp_elf_ex))
706 goto out_free_dentry;
709 /* Flush all traces of the currently running executable */
710 retval = flush_old_exec(bprm);
712 goto out_free_dentry;
716 * Turn off the CS limit completely if exec-shield disabled or
719 if (disable_nx || executable_stack != EXSTACK_DISABLE_X || (__supported_pte_mask & _PAGE_NX))
720 arch_add_exec_range(current->mm, -1);
723 /* OK, This is the point of no return */
724 current->flags &= ~PF_FORKNOEXEC;
725 current->mm->def_flags = def_flags;
727 /* Do this immediately, since STACK_TOP as used in setup_arg_pages
728 may depend on the personality. */
729 SET_PERSONALITY(loc->elf_ex);
730 if (elf_read_implies_exec(loc->elf_ex, executable_stack))
731 current->personality |= READ_IMPLIES_EXEC;
733 if (!(current->personality & ADDR_NO_RANDOMIZE) && randomize_va_space)
734 current->flags |= PF_RANDOMIZE;
736 setup_new_exec(bprm);
738 /* Do this so that we can load the interpreter, if need be. We will
739 change some of these later */
740 current->mm->free_area_cache = current->mm->mmap_base;
741 current->mm->cached_hole_size = 0;
742 retval = setup_arg_pages(bprm, randomize_stack_top(STACK_TOP),
745 send_sig(SIGKILL, current, 0);
746 goto out_free_dentry;
749 current->mm->start_stack = bprm->p;
751 /* Now we do a little grungy work by mmapping the ELF image into
752 the correct location in memory. */
753 for(i = 0, elf_ppnt = elf_phdata;
754 i < loc->elf_ex.e_phnum; i++, elf_ppnt++) {
755 int elf_prot = 0, elf_flags;
756 unsigned long k, vaddr;
758 if (elf_ppnt->p_type != PT_LOAD)
761 if (unlikely (elf_brk > elf_bss)) {
764 /* There was a PT_LOAD segment with p_memsz > p_filesz
765 before this one. Map anonymous pages, if needed,
766 and clear the area. */
767 retval = set_brk(elf_bss + load_bias,
768 elf_brk + load_bias);
770 send_sig(SIGKILL, current, 0);
771 goto out_free_dentry;
773 nbyte = ELF_PAGEOFFSET(elf_bss);
775 nbyte = ELF_MIN_ALIGN - nbyte;
776 if (nbyte > elf_brk - elf_bss)
777 nbyte = elf_brk - elf_bss;
778 if (clear_user((void __user *)elf_bss +
781 * This bss-zeroing can fail if the ELF
782 * file specifies odd protections. So
783 * we don't check the return value
789 if (elf_ppnt->p_flags & PF_R)
790 elf_prot |= PROT_READ;
791 if (elf_ppnt->p_flags & PF_W)
792 elf_prot |= PROT_WRITE;
793 if (elf_ppnt->p_flags & PF_X)
794 elf_prot |= PROT_EXEC;
796 elf_flags = MAP_PRIVATE | MAP_DENYWRITE | MAP_EXECUTABLE;
798 vaddr = elf_ppnt->p_vaddr;
799 if (loc->elf_ex.e_type == ET_EXEC || load_addr_set) {
800 elf_flags |= MAP_FIXED;
801 } else if (loc->elf_ex.e_type == ET_DYN) {
802 /* Try and get dynamic programs out of the way of the
803 * default mmap base, as well as whatever program they
804 * might try to exec. This is because the brk will
805 * follow the loader, and is not movable. */
806 #if defined(CONFIG_X86) || defined(CONFIG_ARM)
807 /* Memory randomization might have been switched off
808 * in runtime via sysctl.
809 * If that is the case, retain the original non-zero
810 * load_bias value in order to establish proper
811 * non-randomized mappings.
813 if (current->flags & PF_RANDOMIZE)
816 load_bias = ELF_PAGESTART(ELF_ET_DYN_BASE - vaddr);
818 load_bias = ELF_PAGESTART(ELF_ET_DYN_BASE - vaddr);
822 error = elf_map(bprm->file, load_bias + vaddr, elf_ppnt,
823 elf_prot, elf_flags, 0);
824 if (BAD_ADDR(error)) {
825 send_sig(SIGKILL, current, 0);
826 retval = IS_ERR((void *)error) ?
827 PTR_ERR((void*)error) : -EINVAL;
828 goto out_free_dentry;
831 if (!load_addr_set) {
833 load_addr = (elf_ppnt->p_vaddr - elf_ppnt->p_offset);
834 if (loc->elf_ex.e_type == ET_DYN) {
836 ELF_PAGESTART(load_bias + vaddr);
837 load_addr += load_bias;
838 reloc_func_desc = load_bias;
841 k = elf_ppnt->p_vaddr;
848 * Check to see if the section's size will overflow the
849 * allowed task size. Note that p_filesz must always be
850 * <= p_memsz so it is only necessary to check p_memsz.
852 if (BAD_ADDR(k) || elf_ppnt->p_filesz > elf_ppnt->p_memsz ||
853 elf_ppnt->p_memsz > TASK_SIZE ||
854 TASK_SIZE - elf_ppnt->p_memsz < k) {
855 /* set_brk can never work. Avoid overflows. */
856 send_sig(SIGKILL, current, 0);
858 goto out_free_dentry;
861 k = elf_ppnt->p_vaddr + elf_ppnt->p_filesz;
865 if ((elf_ppnt->p_flags & PF_X) && end_code < k)
869 k = elf_ppnt->p_vaddr + elf_ppnt->p_memsz;
874 loc->elf_ex.e_entry += load_bias;
875 elf_bss += load_bias;
876 elf_brk += load_bias;
877 start_code += load_bias;
878 end_code += load_bias;
879 start_data += load_bias;
880 end_data += load_bias;
882 /* Calling set_brk effectively mmaps the pages that we need
883 * for the bss and break sections. We must do this before
884 * mapping in the interpreter, to make sure it doesn't wind
885 * up getting placed where the bss needs to go.
887 retval = set_brk(elf_bss, elf_brk);
889 send_sig(SIGKILL, current, 0);
890 goto out_free_dentry;
892 if (likely(elf_bss != elf_brk) && unlikely(padzero(elf_bss))) {
893 send_sig(SIGSEGV, current, 0);
894 retval = -EFAULT; /* Nobody gets to see this, but.. */
895 goto out_free_dentry;
898 if (elf_interpreter) {
899 unsigned long uninitialized_var(interp_map_addr);
901 elf_entry = load_elf_interp(&loc->interp_elf_ex,
905 if (!IS_ERR((void *)elf_entry)) {
907 * load_elf_interp() returns relocation
910 interp_load_addr = elf_entry;
911 elf_entry += loc->interp_elf_ex.e_entry;
913 if (BAD_ADDR(elf_entry)) {
914 force_sig(SIGSEGV, current);
915 retval = IS_ERR((void *)elf_entry) ?
916 (int)elf_entry : -EINVAL;
917 goto out_free_dentry;
919 reloc_func_desc = interp_load_addr;
921 allow_write_access(interpreter);
923 kfree(elf_interpreter);
925 elf_entry = loc->elf_ex.e_entry;
926 if (BAD_ADDR(elf_entry)) {
927 force_sig(SIGSEGV, current);
929 goto out_free_dentry;
935 set_binfmt(&elf_format);
937 #ifdef ARCH_HAS_SETUP_ADDITIONAL_PAGES
938 retval = arch_setup_additional_pages(bprm, !!elf_interpreter);
940 send_sig(SIGKILL, current, 0);
943 #endif /* ARCH_HAS_SETUP_ADDITIONAL_PAGES */
945 install_exec_creds(bprm);
946 current->flags &= ~PF_FORKNOEXEC;
947 retval = create_elf_tables(bprm, &loc->elf_ex,
948 load_addr, interp_load_addr);
950 send_sig(SIGKILL, current, 0);
953 /* N.B. passed_fileno might not be initialized? */
954 current->mm->end_code = end_code;
955 current->mm->start_code = start_code;
956 current->mm->start_data = start_data;
957 current->mm->end_data = end_data;
958 current->mm->start_stack = bprm->p;
960 #ifdef arch_randomize_brk
961 if ((current->flags & PF_RANDOMIZE) && (randomize_va_space > 1)) {
962 current->mm->brk = current->mm->start_brk =
963 arch_randomize_brk(current->mm);
964 #ifdef CONFIG_COMPAT_BRK
965 current->brk_randomized = 1;
970 if (current->personality & MMAP_PAGE_ZERO) {
971 /* Why this, you ask??? Well SVr4 maps page 0 as read-only,
972 and some applications "depend" upon this behavior.
973 Since we do not have the power to recompile these, we
974 emulate the SVr4 behavior. Sigh. */
975 down_write(¤t->mm->mmap_sem);
976 error = do_mmap(NULL, 0, PAGE_SIZE, PROT_READ | PROT_EXEC,
977 MAP_FIXED | MAP_PRIVATE, 0);
978 up_write(¤t->mm->mmap_sem);
983 * The ABI may specify that certain registers be set up in special
984 * ways (on i386 %edx is the address of a DT_FINI function, for
985 * example. In addition, it may also specify (eg, PowerPC64 ELF)
986 * that the e_entry field is the address of the function descriptor
987 * for the startup routine, rather than the address of the startup
988 * routine itself. This macro performs whatever initialization to
989 * the regs structure is required as well as any relocations to the
990 * function descriptor entries when executing dynamically links apps.
992 ELF_PLAT_INIT(regs, reloc_func_desc);
995 start_thread(regs, elf_entry, bprm->p);
1004 allow_write_access(interpreter);
1008 kfree(elf_interpreter);
1014 /* This is really simpleminded and specialized - we are loading an
1015 a.out library that is given an ELF header. */
1016 static int load_elf_library(struct file *file)
1018 struct elf_phdr *elf_phdata;
1019 struct elf_phdr *eppnt;
1020 unsigned long elf_bss, bss, len;
1021 int retval, error, i, j;
1022 struct elfhdr elf_ex;
1025 retval = kernel_read(file, 0, (char *)&elf_ex, sizeof(elf_ex));
1026 if (retval != sizeof(elf_ex))
1029 if (memcmp(elf_ex.e_ident, ELFMAG, SELFMAG) != 0)
1032 /* First of all, some simple consistency checks */
1033 if (elf_ex.e_type != ET_EXEC || elf_ex.e_phnum > 2 ||
1034 !elf_check_arch(&elf_ex) || !file->f_op || !file->f_op->mmap)
1037 /* Now read in all of the header information */
1039 j = sizeof(struct elf_phdr) * elf_ex.e_phnum;
1040 /* j < ELF_MIN_ALIGN because elf_ex.e_phnum <= 2 */
1043 elf_phdata = kmalloc(j, GFP_KERNEL);
1049 retval = kernel_read(file, elf_ex.e_phoff, (char *)eppnt, j);
1053 for (j = 0, i = 0; i<elf_ex.e_phnum; i++)
1054 if ((eppnt + i)->p_type == PT_LOAD)
1059 while (eppnt->p_type != PT_LOAD)
1062 /* Now use mmap to map the library into memory. */
1063 down_write(¤t->mm->mmap_sem);
1064 error = do_mmap(file,
1065 ELF_PAGESTART(eppnt->p_vaddr),
1067 ELF_PAGEOFFSET(eppnt->p_vaddr)),
1068 PROT_READ | PROT_WRITE | PROT_EXEC,
1069 MAP_FIXED | MAP_PRIVATE | MAP_DENYWRITE,
1071 ELF_PAGEOFFSET(eppnt->p_vaddr)));
1072 up_write(¤t->mm->mmap_sem);
1073 if (error != ELF_PAGESTART(eppnt->p_vaddr))
1076 elf_bss = eppnt->p_vaddr + eppnt->p_filesz;
1077 if (padzero(elf_bss)) {
1082 len = ELF_PAGESTART(eppnt->p_filesz + eppnt->p_vaddr +
1084 bss = eppnt->p_memsz + eppnt->p_vaddr;
1086 down_write(¤t->mm->mmap_sem);
1087 do_brk(len, bss - len);
1088 up_write(¤t->mm->mmap_sem);
1098 #ifdef CONFIG_ELF_CORE
1102 * Modelled on fs/exec.c:aout_core_dump()
1103 * Jeremy Fitzhardinge <jeremy@sw.oz.au>
1107 * Decide what to dump of a segment, part, all or none.
1109 static unsigned long vma_dump_size(struct vm_area_struct *vma,
1110 unsigned long mm_flags)
1112 #define FILTER(type) (mm_flags & (1UL << MMF_DUMP_##type))
1114 /* The vma can be set up to tell us the answer directly. */
1115 if (vma->vm_flags & VM_ALWAYSDUMP)
1118 /* Hugetlb memory check */
1119 if (vma->vm_flags & VM_HUGETLB) {
1120 if ((vma->vm_flags & VM_SHARED) && FILTER(HUGETLB_SHARED))
1122 if (!(vma->vm_flags & VM_SHARED) && FILTER(HUGETLB_PRIVATE))
1126 /* Do not dump I/O mapped devices or special mappings */
1127 if (vma->vm_flags & (VM_IO | VM_RESERVED))
1130 /* By default, dump shared memory if mapped from an anonymous file. */
1131 if (vma->vm_flags & VM_SHARED) {
1132 if (vma->vm_file->f_path.dentry->d_inode->i_nlink == 0 ?
1133 FILTER(ANON_SHARED) : FILTER(MAPPED_SHARED))
1138 /* Dump segments that have been written to. */
1139 if (vma->anon_vma && FILTER(ANON_PRIVATE))
1141 if (vma->vm_file == NULL)
1144 if (FILTER(MAPPED_PRIVATE))
1148 * If this looks like the beginning of a DSO or executable mapping,
1149 * check for an ELF header. If we find one, dump the first page to
1150 * aid in determining what was mapped here.
1152 if (FILTER(ELF_HEADERS) &&
1153 vma->vm_pgoff == 0 && (vma->vm_flags & VM_READ)) {
1154 u32 __user *header = (u32 __user *) vma->vm_start;
1156 mm_segment_t fs = get_fs();
1158 * Doing it this way gets the constant folded by GCC.
1162 char elfmag[SELFMAG];
1164 BUILD_BUG_ON(SELFMAG != sizeof word);
1165 magic.elfmag[EI_MAG0] = ELFMAG0;
1166 magic.elfmag[EI_MAG1] = ELFMAG1;
1167 magic.elfmag[EI_MAG2] = ELFMAG2;
1168 magic.elfmag[EI_MAG3] = ELFMAG3;
1170 * Switch to the user "segment" for get_user(),
1171 * then put back what elf_core_dump() had in place.
1174 if (unlikely(get_user(word, header)))
1177 if (word == magic.cmp)
1186 return vma->vm_end - vma->vm_start;
1189 /* An ELF note in memory */
1194 unsigned int datasz;
1198 static int notesize(struct memelfnote *en)
1202 sz = sizeof(struct elf_note);
1203 sz += roundup(strlen(en->name) + 1, 4);
1204 sz += roundup(en->datasz, 4);
1209 #define DUMP_WRITE(addr, nr, foffset) \
1210 do { if (!dump_write(file, (addr), (nr))) return 0; *foffset += (nr); } while(0)
1212 static int alignfile(struct file *file, loff_t *foffset)
1214 static const char buf[4] = { 0, };
1215 DUMP_WRITE(buf, roundup(*foffset, 4) - *foffset, foffset);
1219 static int writenote(struct memelfnote *men, struct file *file,
1223 en.n_namesz = strlen(men->name) + 1;
1224 en.n_descsz = men->datasz;
1225 en.n_type = men->type;
1227 DUMP_WRITE(&en, sizeof(en), foffset);
1228 DUMP_WRITE(men->name, en.n_namesz, foffset);
1229 if (!alignfile(file, foffset))
1231 DUMP_WRITE(men->data, men->datasz, foffset);
1232 if (!alignfile(file, foffset))
1239 static void fill_elf_header(struct elfhdr *elf, int segs,
1240 u16 machine, u32 flags, u8 osabi)
1242 memset(elf, 0, sizeof(*elf));
1244 memcpy(elf->e_ident, ELFMAG, SELFMAG);
1245 elf->e_ident[EI_CLASS] = ELF_CLASS;
1246 elf->e_ident[EI_DATA] = ELF_DATA;
1247 elf->e_ident[EI_VERSION] = EV_CURRENT;
1248 elf->e_ident[EI_OSABI] = ELF_OSABI;
1250 elf->e_type = ET_CORE;
1251 elf->e_machine = machine;
1252 elf->e_version = EV_CURRENT;
1253 elf->e_phoff = sizeof(struct elfhdr);
1254 elf->e_flags = flags;
1255 elf->e_ehsize = sizeof(struct elfhdr);
1256 elf->e_phentsize = sizeof(struct elf_phdr);
1257 elf->e_phnum = segs;
1262 static void fill_elf_note_phdr(struct elf_phdr *phdr, int sz, loff_t offset)
1264 phdr->p_type = PT_NOTE;
1265 phdr->p_offset = offset;
1268 phdr->p_filesz = sz;
1275 static void fill_note(struct memelfnote *note, const char *name, int type,
1276 unsigned int sz, void *data)
1286 * fill up all the fields in prstatus from the given task struct, except
1287 * registers which need to be filled up separately.
1289 static void fill_prstatus(struct elf_prstatus *prstatus,
1290 struct task_struct *p, long signr)
1292 prstatus->pr_info.si_signo = prstatus->pr_cursig = signr;
1293 prstatus->pr_sigpend = p->pending.signal.sig[0];
1294 prstatus->pr_sighold = p->blocked.sig[0];
1296 prstatus->pr_ppid = task_pid_vnr(rcu_dereference(p->real_parent));
1298 prstatus->pr_pid = task_pid_vnr(p);
1299 prstatus->pr_pgrp = task_pgrp_vnr(p);
1300 prstatus->pr_sid = task_session_vnr(p);
1301 if (thread_group_leader(p)) {
1302 struct task_cputime cputime;
1305 * This is the record for the group leader. It shows the
1306 * group-wide total, not its individual thread total.
1308 thread_group_cputime(p, &cputime);
1309 cputime_to_timeval(cputime.utime, &prstatus->pr_utime);
1310 cputime_to_timeval(cputime.stime, &prstatus->pr_stime);
1312 cputime_to_timeval(p->utime, &prstatus->pr_utime);
1313 cputime_to_timeval(p->stime, &prstatus->pr_stime);
1315 cputime_to_timeval(p->signal->cutime, &prstatus->pr_cutime);
1316 cputime_to_timeval(p->signal->cstime, &prstatus->pr_cstime);
1319 static int fill_psinfo(struct elf_prpsinfo *psinfo, struct task_struct *p,
1320 struct mm_struct *mm)
1322 const struct cred *cred;
1323 unsigned int i, len;
1325 /* first copy the parameters from user space */
1326 memset(psinfo, 0, sizeof(struct elf_prpsinfo));
1328 len = mm->arg_end - mm->arg_start;
1329 if (len >= ELF_PRARGSZ)
1330 len = ELF_PRARGSZ-1;
1331 if (copy_from_user(&psinfo->pr_psargs,
1332 (const char __user *)mm->arg_start, len))
1334 for(i = 0; i < len; i++)
1335 if (psinfo->pr_psargs[i] == 0)
1336 psinfo->pr_psargs[i] = ' ';
1337 psinfo->pr_psargs[len] = 0;
1340 psinfo->pr_ppid = task_pid_vnr(rcu_dereference(p->real_parent));
1342 psinfo->pr_pid = task_pid_vnr(p);
1343 psinfo->pr_pgrp = task_pgrp_vnr(p);
1344 psinfo->pr_sid = task_session_vnr(p);
1346 i = p->state ? ffz(~p->state) + 1 : 0;
1347 psinfo->pr_state = i;
1348 psinfo->pr_sname = (i > 5) ? '.' : "RSDTZW"[i];
1349 psinfo->pr_zomb = psinfo->pr_sname == 'Z';
1350 psinfo->pr_nice = task_nice(p);
1351 psinfo->pr_flag = p->flags;
1353 cred = __task_cred(p);
1354 SET_UID(psinfo->pr_uid, cred->uid);
1355 SET_GID(psinfo->pr_gid, cred->gid);
1357 strncpy(psinfo->pr_fname, p->comm, sizeof(psinfo->pr_fname));
1362 static void fill_auxv_note(struct memelfnote *note, struct mm_struct *mm)
1364 elf_addr_t *auxv = (elf_addr_t *) mm->saved_auxv;
1368 while (auxv[i - 2] != AT_NULL);
1369 fill_note(note, "CORE", NT_AUXV, i * sizeof(elf_addr_t), auxv);
1372 #ifdef CORE_DUMP_USE_REGSET
1373 #include <linux/regset.h>
1375 struct elf_thread_core_info {
1376 struct elf_thread_core_info *next;
1377 struct task_struct *task;
1378 struct elf_prstatus prstatus;
1379 struct memelfnote notes[0];
1382 struct elf_note_info {
1383 struct elf_thread_core_info *thread;
1384 struct memelfnote psinfo;
1385 struct memelfnote auxv;
1391 * When a regset has a writeback hook, we call it on each thread before
1392 * dumping user memory. On register window machines, this makes sure the
1393 * user memory backing the register data is up to date before we read it.
1395 static void do_thread_regset_writeback(struct task_struct *task,
1396 const struct user_regset *regset)
1398 if (regset->writeback)
1399 regset->writeback(task, regset, 1);
1402 static int fill_thread_core_info(struct elf_thread_core_info *t,
1403 const struct user_regset_view *view,
1404 long signr, size_t *total)
1409 * NT_PRSTATUS is the one special case, because the regset data
1410 * goes into the pr_reg field inside the note contents, rather
1411 * than being the whole note contents. We fill the reset in here.
1412 * We assume that regset 0 is NT_PRSTATUS.
1414 fill_prstatus(&t->prstatus, t->task, signr);
1415 (void) view->regsets[0].get(t->task, &view->regsets[0],
1416 0, sizeof(t->prstatus.pr_reg),
1417 &t->prstatus.pr_reg, NULL);
1419 fill_note(&t->notes[0], "CORE", NT_PRSTATUS,
1420 sizeof(t->prstatus), &t->prstatus);
1421 *total += notesize(&t->notes[0]);
1423 do_thread_regset_writeback(t->task, &view->regsets[0]);
1426 * Each other regset might generate a note too. For each regset
1427 * that has no core_note_type or is inactive, we leave t->notes[i]
1428 * all zero and we'll know to skip writing it later.
1430 for (i = 1; i < view->n; ++i) {
1431 const struct user_regset *regset = &view->regsets[i];
1432 do_thread_regset_writeback(t->task, regset);
1433 if (regset->core_note_type && regset->get &&
1434 (!regset->active || regset->active(t->task, regset))) {
1436 size_t size = regset->n * regset->size;
1437 void *data = kmalloc(size, GFP_KERNEL);
1438 if (unlikely(!data))
1440 ret = regset->get(t->task, regset,
1441 0, size, data, NULL);
1445 if (regset->core_note_type != NT_PRFPREG)
1446 fill_note(&t->notes[i], "LINUX",
1447 regset->core_note_type,
1450 t->prstatus.pr_fpvalid = 1;
1451 fill_note(&t->notes[i], "CORE",
1452 NT_PRFPREG, size, data);
1454 *total += notesize(&t->notes[i]);
1462 static int fill_note_info(struct elfhdr *elf, int phdrs,
1463 struct elf_note_info *info,
1464 long signr, struct pt_regs *regs)
1466 struct task_struct *dump_task = current;
1467 const struct user_regset_view *view = task_user_regset_view(dump_task);
1468 struct elf_thread_core_info *t;
1469 struct elf_prpsinfo *psinfo;
1470 struct core_thread *ct;
1474 info->thread = NULL;
1476 psinfo = kmalloc(sizeof(*psinfo), GFP_KERNEL);
1480 fill_note(&info->psinfo, "CORE", NT_PRPSINFO, sizeof(*psinfo), psinfo);
1483 * Figure out how many notes we're going to need for each thread.
1485 info->thread_notes = 0;
1486 for (i = 0; i < view->n; ++i)
1487 if (view->regsets[i].core_note_type != 0)
1488 ++info->thread_notes;
1491 * Sanity check. We rely on regset 0 being in NT_PRSTATUS,
1492 * since it is our one special case.
1494 if (unlikely(info->thread_notes == 0) ||
1495 unlikely(view->regsets[0].core_note_type != NT_PRSTATUS)) {
1501 * Initialize the ELF file header.
1503 fill_elf_header(elf, phdrs,
1504 view->e_machine, view->e_flags, view->ei_osabi);
1507 * Allocate a structure for each thread.
1509 for (ct = &dump_task->mm->core_state->dumper; ct; ct = ct->next) {
1510 t = kzalloc(offsetof(struct elf_thread_core_info,
1511 notes[info->thread_notes]),
1517 if (ct->task == dump_task || !info->thread) {
1518 t->next = info->thread;
1522 * Make sure to keep the original task at
1523 * the head of the list.
1525 t->next = info->thread->next;
1526 info->thread->next = t;
1531 * Now fill in each thread's information.
1533 for (t = info->thread; t != NULL; t = t->next)
1534 if (!fill_thread_core_info(t, view, signr, &info->size))
1538 * Fill in the two process-wide notes.
1540 fill_psinfo(psinfo, dump_task->group_leader, dump_task->mm);
1541 info->size += notesize(&info->psinfo);
1543 fill_auxv_note(&info->auxv, current->mm);
1544 info->size += notesize(&info->auxv);
1549 static size_t get_note_info_size(struct elf_note_info *info)
1555 * Write all the notes for each thread. When writing the first thread, the
1556 * process-wide notes are interleaved after the first thread-specific note.
1558 static int write_note_info(struct elf_note_info *info,
1559 struct file *file, loff_t *foffset)
1562 struct elf_thread_core_info *t = info->thread;
1567 if (!writenote(&t->notes[0], file, foffset))
1570 if (first && !writenote(&info->psinfo, file, foffset))
1572 if (first && !writenote(&info->auxv, file, foffset))
1575 for (i = 1; i < info->thread_notes; ++i)
1576 if (t->notes[i].data &&
1577 !writenote(&t->notes[i], file, foffset))
1587 static void free_note_info(struct elf_note_info *info)
1589 struct elf_thread_core_info *threads = info->thread;
1592 struct elf_thread_core_info *t = threads;
1594 WARN_ON(t->notes[0].data && t->notes[0].data != &t->prstatus);
1595 for (i = 1; i < info->thread_notes; ++i)
1596 kfree(t->notes[i].data);
1599 kfree(info->psinfo.data);
1604 /* Here is the structure in which status of each thread is captured. */
1605 struct elf_thread_status
1607 struct list_head list;
1608 struct elf_prstatus prstatus; /* NT_PRSTATUS */
1609 elf_fpregset_t fpu; /* NT_PRFPREG */
1610 struct task_struct *thread;
1611 #ifdef ELF_CORE_COPY_XFPREGS
1612 elf_fpxregset_t xfpu; /* ELF_CORE_XFPREG_TYPE */
1614 struct memelfnote notes[3];
1619 * In order to add the specific thread information for the elf file format,
1620 * we need to keep a linked list of every threads pr_status and then create
1621 * a single section for them in the final core file.
1623 static int elf_dump_thread_status(long signr, struct elf_thread_status *t)
1626 struct task_struct *p = t->thread;
1629 fill_prstatus(&t->prstatus, p, signr);
1630 elf_core_copy_task_regs(p, &t->prstatus.pr_reg);
1632 fill_note(&t->notes[0], "CORE", NT_PRSTATUS, sizeof(t->prstatus),
1635 sz += notesize(&t->notes[0]);
1637 if ((t->prstatus.pr_fpvalid = elf_core_copy_task_fpregs(p, NULL,
1639 fill_note(&t->notes[1], "CORE", NT_PRFPREG, sizeof(t->fpu),
1642 sz += notesize(&t->notes[1]);
1645 #ifdef ELF_CORE_COPY_XFPREGS
1646 if (elf_core_copy_task_xfpregs(p, &t->xfpu)) {
1647 fill_note(&t->notes[2], "LINUX", ELF_CORE_XFPREG_TYPE,
1648 sizeof(t->xfpu), &t->xfpu);
1650 sz += notesize(&t->notes[2]);
1656 struct elf_note_info {
1657 struct memelfnote *notes;
1658 struct elf_prstatus *prstatus; /* NT_PRSTATUS */
1659 struct elf_prpsinfo *psinfo; /* NT_PRPSINFO */
1660 struct list_head thread_list;
1661 elf_fpregset_t *fpu;
1662 #ifdef ELF_CORE_COPY_XFPREGS
1663 elf_fpxregset_t *xfpu;
1665 int thread_status_size;
1669 static int elf_note_info_init(struct elf_note_info *info)
1671 memset(info, 0, sizeof(*info));
1672 INIT_LIST_HEAD(&info->thread_list);
1674 /* Allocate space for six ELF notes */
1675 info->notes = kmalloc(6 * sizeof(struct memelfnote), GFP_KERNEL);
1678 info->psinfo = kmalloc(sizeof(*info->psinfo), GFP_KERNEL);
1681 info->prstatus = kmalloc(sizeof(*info->prstatus), GFP_KERNEL);
1682 if (!info->prstatus)
1684 info->fpu = kmalloc(sizeof(*info->fpu), GFP_KERNEL);
1687 #ifdef ELF_CORE_COPY_XFPREGS
1688 info->xfpu = kmalloc(sizeof(*info->xfpu), GFP_KERNEL);
1693 #ifdef ELF_CORE_COPY_XFPREGS
1698 kfree(info->prstatus);
1700 kfree(info->psinfo);
1706 static int fill_note_info(struct elfhdr *elf, int phdrs,
1707 struct elf_note_info *info,
1708 long signr, struct pt_regs *regs)
1710 struct list_head *t;
1712 if (!elf_note_info_init(info))
1716 struct core_thread *ct;
1717 struct elf_thread_status *ets;
1719 for (ct = current->mm->core_state->dumper.next;
1720 ct; ct = ct->next) {
1721 ets = kzalloc(sizeof(*ets), GFP_KERNEL);
1725 ets->thread = ct->task;
1726 list_add(&ets->list, &info->thread_list);
1729 list_for_each(t, &info->thread_list) {
1732 ets = list_entry(t, struct elf_thread_status, list);
1733 sz = elf_dump_thread_status(signr, ets);
1734 info->thread_status_size += sz;
1737 /* now collect the dump for the current */
1738 memset(info->prstatus, 0, sizeof(*info->prstatus));
1739 fill_prstatus(info->prstatus, current, signr);
1740 elf_core_copy_regs(&info->prstatus->pr_reg, regs);
1743 fill_elf_header(elf, phdrs, ELF_ARCH, ELF_CORE_EFLAGS, ELF_OSABI);
1746 * Set up the notes in similar form to SVR4 core dumps made
1747 * with info from their /proc.
1750 fill_note(info->notes + 0, "CORE", NT_PRSTATUS,
1751 sizeof(*info->prstatus), info->prstatus);
1752 fill_psinfo(info->psinfo, current->group_leader, current->mm);
1753 fill_note(info->notes + 1, "CORE", NT_PRPSINFO,
1754 sizeof(*info->psinfo), info->psinfo);
1758 fill_auxv_note(&info->notes[info->numnote++], current->mm);
1760 /* Try to dump the FPU. */
1761 info->prstatus->pr_fpvalid = elf_core_copy_task_fpregs(current, regs,
1763 if (info->prstatus->pr_fpvalid)
1764 fill_note(info->notes + info->numnote++,
1765 "CORE", NT_PRFPREG, sizeof(*info->fpu), info->fpu);
1766 #ifdef ELF_CORE_COPY_XFPREGS
1767 if (elf_core_copy_task_xfpregs(current, info->xfpu))
1768 fill_note(info->notes + info->numnote++,
1769 "LINUX", ELF_CORE_XFPREG_TYPE,
1770 sizeof(*info->xfpu), info->xfpu);
1776 static size_t get_note_info_size(struct elf_note_info *info)
1781 for (i = 0; i < info->numnote; i++)
1782 sz += notesize(info->notes + i);
1784 sz += info->thread_status_size;
1789 static int write_note_info(struct elf_note_info *info,
1790 struct file *file, loff_t *foffset)
1793 struct list_head *t;
1795 for (i = 0; i < info->numnote; i++)
1796 if (!writenote(info->notes + i, file, foffset))
1799 /* write out the thread status notes section */
1800 list_for_each(t, &info->thread_list) {
1801 struct elf_thread_status *tmp =
1802 list_entry(t, struct elf_thread_status, list);
1804 for (i = 0; i < tmp->num_notes; i++)
1805 if (!writenote(&tmp->notes[i], file, foffset))
1812 static void free_note_info(struct elf_note_info *info)
1814 while (!list_empty(&info->thread_list)) {
1815 struct list_head *tmp = info->thread_list.next;
1817 kfree(list_entry(tmp, struct elf_thread_status, list));
1820 kfree(info->prstatus);
1821 kfree(info->psinfo);
1824 #ifdef ELF_CORE_COPY_XFPREGS
1831 static struct vm_area_struct *first_vma(struct task_struct *tsk,
1832 struct vm_area_struct *gate_vma)
1834 struct vm_area_struct *ret = tsk->mm->mmap;
1841 * Helper function for iterating across a vma list. It ensures that the caller
1842 * will visit `gate_vma' prior to terminating the search.
1844 static struct vm_area_struct *next_vma(struct vm_area_struct *this_vma,
1845 struct vm_area_struct *gate_vma)
1847 struct vm_area_struct *ret;
1849 ret = this_vma->vm_next;
1852 if (this_vma == gate_vma)
1857 static void fill_extnum_info(struct elfhdr *elf, struct elf_shdr *shdr4extnum,
1858 elf_addr_t e_shoff, int segs)
1860 elf->e_shoff = e_shoff;
1861 elf->e_shentsize = sizeof(*shdr4extnum);
1863 elf->e_shstrndx = SHN_UNDEF;
1865 memset(shdr4extnum, 0, sizeof(*shdr4extnum));
1867 shdr4extnum->sh_type = SHT_NULL;
1868 shdr4extnum->sh_size = elf->e_shnum;
1869 shdr4extnum->sh_link = elf->e_shstrndx;
1870 shdr4extnum->sh_info = segs;
1873 static size_t elf_core_vma_data_size(struct vm_area_struct *gate_vma,
1874 unsigned long mm_flags)
1876 struct vm_area_struct *vma;
1879 for (vma = first_vma(current, gate_vma); vma != NULL;
1880 vma = next_vma(vma, gate_vma))
1881 size += vma_dump_size(vma, mm_flags);
1888 * This is a two-pass process; first we find the offsets of the bits,
1889 * and then they are actually written out. If we run out of core limit
1892 static int elf_core_dump(struct coredump_params *cprm)
1898 struct vm_area_struct *vma, *gate_vma;
1899 struct elfhdr *elf = NULL;
1900 loff_t offset = 0, dataoff, foffset;
1901 struct elf_note_info info;
1902 struct elf_phdr *phdr4note = NULL;
1903 struct elf_shdr *shdr4extnum = NULL;
1908 * We no longer stop all VM operations.
1910 * This is because those proceses that could possibly change map_count
1911 * or the mmap / vma pages are now blocked in do_exit on current
1912 * finishing this core dump.
1914 * Only ptrace can touch these memory addresses, but it doesn't change
1915 * the map_count or the pages allocated. So no possibility of crashing
1916 * exists while dumping the mm->vm_next areas to the core file.
1919 /* alloc memory for large data structures: too large to be on stack */
1920 elf = kmalloc(sizeof(*elf), GFP_KERNEL);
1924 * The number of segs are recored into ELF header as 16bit value.
1925 * Please check DEFAULT_MAX_MAP_COUNT definition when you modify here.
1927 segs = current->mm->map_count;
1928 segs += elf_core_extra_phdrs();
1930 gate_vma = get_gate_vma(current->mm);
1931 if (gate_vma != NULL)
1934 /* for notes section */
1937 /* If segs > PN_XNUM(0xffff), then e_phnum overflows. To avoid
1938 * this, kernel supports extended numbering. Have a look at
1939 * include/linux/elf.h for further information. */
1940 e_phnum = segs > PN_XNUM ? PN_XNUM : segs;
1943 * Collect all the non-memory information about the process for the
1944 * notes. This also sets up the file header.
1946 if (!fill_note_info(elf, e_phnum, &info, cprm->signr, cprm->regs))
1950 current->flags |= PF_DUMPCORE;
1955 offset += sizeof(*elf); /* Elf header */
1956 offset += segs * sizeof(struct elf_phdr); /* Program headers */
1959 /* Write notes phdr entry */
1961 size_t sz = get_note_info_size(&info);
1963 sz += elf_coredump_extra_notes_size();
1965 phdr4note = kmalloc(sizeof(*phdr4note), GFP_KERNEL);
1969 fill_elf_note_phdr(phdr4note, sz, offset);
1973 dataoff = offset = roundup(offset, ELF_EXEC_PAGESIZE);
1975 offset += elf_core_vma_data_size(gate_vma, cprm->mm_flags);
1976 offset += elf_core_extra_data_size();
1979 if (e_phnum == PN_XNUM) {
1980 shdr4extnum = kmalloc(sizeof(*shdr4extnum), GFP_KERNEL);
1983 fill_extnum_info(elf, shdr4extnum, e_shoff, segs);
1988 size += sizeof(*elf);
1989 if (size > cprm->limit || !dump_write(cprm->file, elf, sizeof(*elf)))
1992 size += sizeof(*phdr4note);
1993 if (size > cprm->limit
1994 || !dump_write(cprm->file, phdr4note, sizeof(*phdr4note)))
1997 /* Write program headers for segments dump */
1998 for (vma = first_vma(current, gate_vma); vma != NULL;
1999 vma = next_vma(vma, gate_vma)) {
2000 struct elf_phdr phdr;
2002 phdr.p_type = PT_LOAD;
2003 phdr.p_offset = offset;
2004 phdr.p_vaddr = vma->vm_start;
2006 phdr.p_filesz = vma_dump_size(vma, cprm->mm_flags);
2007 phdr.p_memsz = vma->vm_end - vma->vm_start;
2008 offset += phdr.p_filesz;
2009 phdr.p_flags = vma->vm_flags & VM_READ ? PF_R : 0;
2010 if (vma->vm_flags & VM_WRITE)
2011 phdr.p_flags |= PF_W;
2012 if (vma->vm_flags & VM_EXEC)
2013 phdr.p_flags |= PF_X;
2014 phdr.p_align = ELF_EXEC_PAGESIZE;
2016 size += sizeof(phdr);
2017 if (size > cprm->limit
2018 || !dump_write(cprm->file, &phdr, sizeof(phdr)))
2022 if (!elf_core_write_extra_phdrs(cprm->file, offset, &size, cprm->limit))
2025 /* write out the notes section */
2026 if (!write_note_info(&info, cprm->file, &foffset))
2029 if (elf_coredump_extra_notes_write(cprm->file, &foffset))
2033 if (!dump_seek(cprm->file, dataoff - foffset))
2036 for (vma = first_vma(current, gate_vma); vma != NULL;
2037 vma = next_vma(vma, gate_vma)) {
2041 end = vma->vm_start + vma_dump_size(vma, cprm->mm_flags);
2043 for (addr = vma->vm_start; addr < end; addr += PAGE_SIZE) {
2047 page = get_dump_page(addr);
2049 void *kaddr = kmap(page);
2050 stop = ((size += PAGE_SIZE) > cprm->limit) ||
2051 !dump_write(cprm->file, kaddr,
2054 page_cache_release(page);
2056 stop = !dump_seek(cprm->file, PAGE_SIZE);
2062 if (!elf_core_write_extra_data(cprm->file, &size, cprm->limit))
2065 if (e_phnum == PN_XNUM) {
2066 size += sizeof(*shdr4extnum);
2067 if (size > cprm->limit
2068 || !dump_write(cprm->file, shdr4extnum,
2069 sizeof(*shdr4extnum)))
2077 free_note_info(&info);
2085 #endif /* CONFIG_ELF_CORE */
2087 static int __init init_elf_binfmt(void)
2089 return register_binfmt(&elf_format);
2092 static void __exit exit_elf_binfmt(void)
2094 /* Remove the COFF and ELF loaders. */
2095 unregister_binfmt(&elf_format);
2098 core_initcall(init_elf_binfmt);
2099 module_exit(exit_elf_binfmt);
2100 MODULE_LICENSE("GPL");