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;
714 /* OK, This is the point of no return */
715 current->flags &= ~PF_FORKNOEXEC;
716 current->mm->def_flags = def_flags;
718 /* Do this immediately, since STACK_TOP as used in setup_arg_pages
719 may depend on the personality. */
720 SET_PERSONALITY(loc->elf_ex);
721 if (elf_read_implies_exec(loc->elf_ex, executable_stack))
722 current->personality |= READ_IMPLIES_EXEC;
724 if (!(current->personality & ADDR_NO_RANDOMIZE) && randomize_va_space)
725 current->flags |= PF_RANDOMIZE;
727 setup_new_exec(bprm);
729 /* Do this so that we can load the interpreter, if need be. We will
730 change some of these later */
731 current->mm->free_area_cache = current->mm->mmap_base;
732 current->mm->cached_hole_size = 0;
733 retval = setup_arg_pages(bprm, randomize_stack_top(STACK_TOP),
736 send_sig(SIGKILL, current, 0);
737 goto out_free_dentry;
740 current->mm->start_stack = bprm->p;
742 /* Now we do a little grungy work by mmapping the ELF image into
743 the correct location in memory. */
744 for(i = 0, elf_ppnt = elf_phdata;
745 i < loc->elf_ex.e_phnum; i++, elf_ppnt++) {
746 int elf_prot = 0, elf_flags;
747 unsigned long k, vaddr;
749 if (elf_ppnt->p_type != PT_LOAD)
752 if (unlikely (elf_brk > elf_bss)) {
755 /* There was a PT_LOAD segment with p_memsz > p_filesz
756 before this one. Map anonymous pages, if needed,
757 and clear the area. */
758 retval = set_brk(elf_bss + load_bias,
759 elf_brk + load_bias);
761 send_sig(SIGKILL, current, 0);
762 goto out_free_dentry;
764 nbyte = ELF_PAGEOFFSET(elf_bss);
766 nbyte = ELF_MIN_ALIGN - nbyte;
767 if (nbyte > elf_brk - elf_bss)
768 nbyte = elf_brk - elf_bss;
769 if (clear_user((void __user *)elf_bss +
772 * This bss-zeroing can fail if the ELF
773 * file specifies odd protections. So
774 * we don't check the return value
780 if (elf_ppnt->p_flags & PF_R)
781 elf_prot |= PROT_READ;
782 if (elf_ppnt->p_flags & PF_W)
783 elf_prot |= PROT_WRITE;
784 if (elf_ppnt->p_flags & PF_X)
785 elf_prot |= PROT_EXEC;
787 elf_flags = MAP_PRIVATE | MAP_DENYWRITE | MAP_EXECUTABLE;
789 vaddr = elf_ppnt->p_vaddr;
790 if (loc->elf_ex.e_type == ET_EXEC || load_addr_set) {
791 elf_flags |= MAP_FIXED;
792 } else if (loc->elf_ex.e_type == ET_DYN) {
793 /* Try and get dynamic programs out of the way of the
794 * default mmap base, as well as whatever program they
795 * might try to exec. This is because the brk will
796 * follow the loader, and is not movable. */
797 #if defined(CONFIG_X86) || defined(CONFIG_ARM)
800 load_bias = ELF_PAGESTART(ELF_ET_DYN_BASE - vaddr);
804 error = elf_map(bprm->file, load_bias + vaddr, elf_ppnt,
805 elf_prot, elf_flags, 0);
806 if (BAD_ADDR(error)) {
807 send_sig(SIGKILL, current, 0);
808 retval = IS_ERR((void *)error) ?
809 PTR_ERR((void*)error) : -EINVAL;
810 goto out_free_dentry;
813 if (!load_addr_set) {
815 load_addr = (elf_ppnt->p_vaddr - elf_ppnt->p_offset);
816 if (loc->elf_ex.e_type == ET_DYN) {
818 ELF_PAGESTART(load_bias + vaddr);
819 load_addr += load_bias;
820 reloc_func_desc = load_bias;
823 k = elf_ppnt->p_vaddr;
830 * Check to see if the section's size will overflow the
831 * allowed task size. Note that p_filesz must always be
832 * <= p_memsz so it is only necessary to check p_memsz.
834 if (BAD_ADDR(k) || elf_ppnt->p_filesz > elf_ppnt->p_memsz ||
835 elf_ppnt->p_memsz > TASK_SIZE ||
836 TASK_SIZE - elf_ppnt->p_memsz < k) {
837 /* set_brk can never work. Avoid overflows. */
838 send_sig(SIGKILL, current, 0);
840 goto out_free_dentry;
843 k = elf_ppnt->p_vaddr + elf_ppnt->p_filesz;
847 if ((elf_ppnt->p_flags & PF_X) && end_code < k)
851 k = elf_ppnt->p_vaddr + elf_ppnt->p_memsz;
856 loc->elf_ex.e_entry += load_bias;
857 elf_bss += load_bias;
858 elf_brk += load_bias;
859 start_code += load_bias;
860 end_code += load_bias;
861 start_data += load_bias;
862 end_data += load_bias;
864 /* Calling set_brk effectively mmaps the pages that we need
865 * for the bss and break sections. We must do this before
866 * mapping in the interpreter, to make sure it doesn't wind
867 * up getting placed where the bss needs to go.
869 retval = set_brk(elf_bss, elf_brk);
871 send_sig(SIGKILL, current, 0);
872 goto out_free_dentry;
874 if (likely(elf_bss != elf_brk) && unlikely(padzero(elf_bss))) {
875 send_sig(SIGSEGV, current, 0);
876 retval = -EFAULT; /* Nobody gets to see this, but.. */
877 goto out_free_dentry;
880 if (elf_interpreter) {
881 unsigned long uninitialized_var(interp_map_addr);
883 elf_entry = load_elf_interp(&loc->interp_elf_ex,
887 if (!IS_ERR((void *)elf_entry)) {
889 * load_elf_interp() returns relocation
892 interp_load_addr = elf_entry;
893 elf_entry += loc->interp_elf_ex.e_entry;
895 if (BAD_ADDR(elf_entry)) {
896 force_sig(SIGSEGV, current);
897 retval = IS_ERR((void *)elf_entry) ?
898 (int)elf_entry : -EINVAL;
899 goto out_free_dentry;
901 reloc_func_desc = interp_load_addr;
903 allow_write_access(interpreter);
905 kfree(elf_interpreter);
907 elf_entry = loc->elf_ex.e_entry;
908 if (BAD_ADDR(elf_entry)) {
909 force_sig(SIGSEGV, current);
911 goto out_free_dentry;
917 set_binfmt(&elf_format);
919 #ifdef ARCH_HAS_SETUP_ADDITIONAL_PAGES
920 retval = arch_setup_additional_pages(bprm, !!elf_interpreter);
922 send_sig(SIGKILL, current, 0);
925 #endif /* ARCH_HAS_SETUP_ADDITIONAL_PAGES */
927 install_exec_creds(bprm);
928 current->flags &= ~PF_FORKNOEXEC;
929 retval = create_elf_tables(bprm, &loc->elf_ex,
930 load_addr, interp_load_addr);
932 send_sig(SIGKILL, current, 0);
935 /* N.B. passed_fileno might not be initialized? */
936 current->mm->end_code = end_code;
937 current->mm->start_code = start_code;
938 current->mm->start_data = start_data;
939 current->mm->end_data = end_data;
940 current->mm->start_stack = bprm->p;
942 #ifdef arch_randomize_brk
943 if ((current->flags & PF_RANDOMIZE) && (randomize_va_space > 1)) {
944 current->mm->brk = current->mm->start_brk =
945 arch_randomize_brk(current->mm);
946 #ifdef CONFIG_COMPAT_BRK
947 current->brk_randomized = 1;
952 if (current->personality & MMAP_PAGE_ZERO) {
953 /* Why this, you ask??? Well SVr4 maps page 0 as read-only,
954 and some applications "depend" upon this behavior.
955 Since we do not have the power to recompile these, we
956 emulate the SVr4 behavior. Sigh. */
957 down_write(¤t->mm->mmap_sem);
958 error = do_mmap(NULL, 0, PAGE_SIZE, PROT_READ | PROT_EXEC,
959 MAP_FIXED | MAP_PRIVATE, 0);
960 up_write(¤t->mm->mmap_sem);
965 * The ABI may specify that certain registers be set up in special
966 * ways (on i386 %edx is the address of a DT_FINI function, for
967 * example. In addition, it may also specify (eg, PowerPC64 ELF)
968 * that the e_entry field is the address of the function descriptor
969 * for the startup routine, rather than the address of the startup
970 * routine itself. This macro performs whatever initialization to
971 * the regs structure is required as well as any relocations to the
972 * function descriptor entries when executing dynamically links apps.
974 ELF_PLAT_INIT(regs, reloc_func_desc);
977 start_thread(regs, elf_entry, bprm->p);
986 allow_write_access(interpreter);
990 kfree(elf_interpreter);
996 /* This is really simpleminded and specialized - we are loading an
997 a.out library that is given an ELF header. */
998 static int load_elf_library(struct file *file)
1000 struct elf_phdr *elf_phdata;
1001 struct elf_phdr *eppnt;
1002 unsigned long elf_bss, bss, len;
1003 int retval, error, i, j;
1004 struct elfhdr elf_ex;
1007 retval = kernel_read(file, 0, (char *)&elf_ex, sizeof(elf_ex));
1008 if (retval != sizeof(elf_ex))
1011 if (memcmp(elf_ex.e_ident, ELFMAG, SELFMAG) != 0)
1014 /* First of all, some simple consistency checks */
1015 if (elf_ex.e_type != ET_EXEC || elf_ex.e_phnum > 2 ||
1016 !elf_check_arch(&elf_ex) || !file->f_op || !file->f_op->mmap)
1019 /* Now read in all of the header information */
1021 j = sizeof(struct elf_phdr) * elf_ex.e_phnum;
1022 /* j < ELF_MIN_ALIGN because elf_ex.e_phnum <= 2 */
1025 elf_phdata = kmalloc(j, GFP_KERNEL);
1031 retval = kernel_read(file, elf_ex.e_phoff, (char *)eppnt, j);
1035 for (j = 0, i = 0; i<elf_ex.e_phnum; i++)
1036 if ((eppnt + i)->p_type == PT_LOAD)
1041 while (eppnt->p_type != PT_LOAD)
1044 /* Now use mmap to map the library into memory. */
1045 down_write(¤t->mm->mmap_sem);
1046 error = do_mmap(file,
1047 ELF_PAGESTART(eppnt->p_vaddr),
1049 ELF_PAGEOFFSET(eppnt->p_vaddr)),
1050 PROT_READ | PROT_WRITE | PROT_EXEC,
1051 MAP_FIXED | MAP_PRIVATE | MAP_DENYWRITE,
1053 ELF_PAGEOFFSET(eppnt->p_vaddr)));
1054 up_write(¤t->mm->mmap_sem);
1055 if (error != ELF_PAGESTART(eppnt->p_vaddr))
1058 elf_bss = eppnt->p_vaddr + eppnt->p_filesz;
1059 if (padzero(elf_bss)) {
1064 len = ELF_PAGESTART(eppnt->p_filesz + eppnt->p_vaddr +
1066 bss = eppnt->p_memsz + eppnt->p_vaddr;
1068 down_write(¤t->mm->mmap_sem);
1069 do_brk(len, bss - len);
1070 up_write(¤t->mm->mmap_sem);
1080 #ifdef CONFIG_ELF_CORE
1084 * Modelled on fs/exec.c:aout_core_dump()
1085 * Jeremy Fitzhardinge <jeremy@sw.oz.au>
1089 * Decide what to dump of a segment, part, all or none.
1091 static unsigned long vma_dump_size(struct vm_area_struct *vma,
1092 unsigned long mm_flags)
1094 #define FILTER(type) (mm_flags & (1UL << MMF_DUMP_##type))
1096 /* The vma can be set up to tell us the answer directly. */
1097 if (vma->vm_flags & VM_ALWAYSDUMP)
1100 /* Hugetlb memory check */
1101 if (vma->vm_flags & VM_HUGETLB) {
1102 if ((vma->vm_flags & VM_SHARED) && FILTER(HUGETLB_SHARED))
1104 if (!(vma->vm_flags & VM_SHARED) && FILTER(HUGETLB_PRIVATE))
1108 /* Do not dump I/O mapped devices or special mappings */
1109 if (vma->vm_flags & (VM_IO | VM_RESERVED))
1112 /* By default, dump shared memory if mapped from an anonymous file. */
1113 if (vma->vm_flags & VM_SHARED) {
1114 if (vma->vm_file->f_path.dentry->d_inode->i_nlink == 0 ?
1115 FILTER(ANON_SHARED) : FILTER(MAPPED_SHARED))
1120 /* Dump segments that have been written to. */
1121 if (vma->anon_vma && FILTER(ANON_PRIVATE))
1123 if (vma->vm_file == NULL)
1126 if (FILTER(MAPPED_PRIVATE))
1130 * If this looks like the beginning of a DSO or executable mapping,
1131 * check for an ELF header. If we find one, dump the first page to
1132 * aid in determining what was mapped here.
1134 if (FILTER(ELF_HEADERS) &&
1135 vma->vm_pgoff == 0 && (vma->vm_flags & VM_READ)) {
1136 u32 __user *header = (u32 __user *) vma->vm_start;
1138 mm_segment_t fs = get_fs();
1140 * Doing it this way gets the constant folded by GCC.
1144 char elfmag[SELFMAG];
1146 BUILD_BUG_ON(SELFMAG != sizeof word);
1147 magic.elfmag[EI_MAG0] = ELFMAG0;
1148 magic.elfmag[EI_MAG1] = ELFMAG1;
1149 magic.elfmag[EI_MAG2] = ELFMAG2;
1150 magic.elfmag[EI_MAG3] = ELFMAG3;
1152 * Switch to the user "segment" for get_user(),
1153 * then put back what elf_core_dump() had in place.
1156 if (unlikely(get_user(word, header)))
1159 if (word == magic.cmp)
1168 return vma->vm_end - vma->vm_start;
1171 /* An ELF note in memory */
1176 unsigned int datasz;
1180 static int notesize(struct memelfnote *en)
1184 sz = sizeof(struct elf_note);
1185 sz += roundup(strlen(en->name) + 1, 4);
1186 sz += roundup(en->datasz, 4);
1191 #define DUMP_WRITE(addr, nr, foffset) \
1192 do { if (!dump_write(file, (addr), (nr))) return 0; *foffset += (nr); } while(0)
1194 static int alignfile(struct file *file, loff_t *foffset)
1196 static const char buf[4] = { 0, };
1197 DUMP_WRITE(buf, roundup(*foffset, 4) - *foffset, foffset);
1201 static int writenote(struct memelfnote *men, struct file *file,
1205 en.n_namesz = strlen(men->name) + 1;
1206 en.n_descsz = men->datasz;
1207 en.n_type = men->type;
1209 DUMP_WRITE(&en, sizeof(en), foffset);
1210 DUMP_WRITE(men->name, en.n_namesz, foffset);
1211 if (!alignfile(file, foffset))
1213 DUMP_WRITE(men->data, men->datasz, foffset);
1214 if (!alignfile(file, foffset))
1221 static void fill_elf_header(struct elfhdr *elf, int segs,
1222 u16 machine, u32 flags, u8 osabi)
1224 memset(elf, 0, sizeof(*elf));
1226 memcpy(elf->e_ident, ELFMAG, SELFMAG);
1227 elf->e_ident[EI_CLASS] = ELF_CLASS;
1228 elf->e_ident[EI_DATA] = ELF_DATA;
1229 elf->e_ident[EI_VERSION] = EV_CURRENT;
1230 elf->e_ident[EI_OSABI] = ELF_OSABI;
1232 elf->e_type = ET_CORE;
1233 elf->e_machine = machine;
1234 elf->e_version = EV_CURRENT;
1235 elf->e_phoff = sizeof(struct elfhdr);
1236 elf->e_flags = flags;
1237 elf->e_ehsize = sizeof(struct elfhdr);
1238 elf->e_phentsize = sizeof(struct elf_phdr);
1239 elf->e_phnum = segs;
1244 static void fill_elf_note_phdr(struct elf_phdr *phdr, int sz, loff_t offset)
1246 phdr->p_type = PT_NOTE;
1247 phdr->p_offset = offset;
1250 phdr->p_filesz = sz;
1257 static void fill_note(struct memelfnote *note, const char *name, int type,
1258 unsigned int sz, void *data)
1268 * fill up all the fields in prstatus from the given task struct, except
1269 * registers which need to be filled up separately.
1271 static void fill_prstatus(struct elf_prstatus *prstatus,
1272 struct task_struct *p, long signr)
1274 prstatus->pr_info.si_signo = prstatus->pr_cursig = signr;
1275 prstatus->pr_sigpend = p->pending.signal.sig[0];
1276 prstatus->pr_sighold = p->blocked.sig[0];
1278 prstatus->pr_ppid = task_pid_vnr(rcu_dereference(p->real_parent));
1280 prstatus->pr_pid = task_pid_vnr(p);
1281 prstatus->pr_pgrp = task_pgrp_vnr(p);
1282 prstatus->pr_sid = task_session_vnr(p);
1283 if (thread_group_leader(p)) {
1284 struct task_cputime cputime;
1287 * This is the record for the group leader. It shows the
1288 * group-wide total, not its individual thread total.
1290 thread_group_cputime(p, &cputime);
1291 cputime_to_timeval(cputime.utime, &prstatus->pr_utime);
1292 cputime_to_timeval(cputime.stime, &prstatus->pr_stime);
1294 cputime_to_timeval(p->utime, &prstatus->pr_utime);
1295 cputime_to_timeval(p->stime, &prstatus->pr_stime);
1297 cputime_to_timeval(p->signal->cutime, &prstatus->pr_cutime);
1298 cputime_to_timeval(p->signal->cstime, &prstatus->pr_cstime);
1301 static int fill_psinfo(struct elf_prpsinfo *psinfo, struct task_struct *p,
1302 struct mm_struct *mm)
1304 const struct cred *cred;
1305 unsigned int i, len;
1307 /* first copy the parameters from user space */
1308 memset(psinfo, 0, sizeof(struct elf_prpsinfo));
1310 len = mm->arg_end - mm->arg_start;
1311 if (len >= ELF_PRARGSZ)
1312 len = ELF_PRARGSZ-1;
1313 if (copy_from_user(&psinfo->pr_psargs,
1314 (const char __user *)mm->arg_start, len))
1316 for(i = 0; i < len; i++)
1317 if (psinfo->pr_psargs[i] == 0)
1318 psinfo->pr_psargs[i] = ' ';
1319 psinfo->pr_psargs[len] = 0;
1322 psinfo->pr_ppid = task_pid_vnr(rcu_dereference(p->real_parent));
1324 psinfo->pr_pid = task_pid_vnr(p);
1325 psinfo->pr_pgrp = task_pgrp_vnr(p);
1326 psinfo->pr_sid = task_session_vnr(p);
1328 i = p->state ? ffz(~p->state) + 1 : 0;
1329 psinfo->pr_state = i;
1330 psinfo->pr_sname = (i > 5) ? '.' : "RSDTZW"[i];
1331 psinfo->pr_zomb = psinfo->pr_sname == 'Z';
1332 psinfo->pr_nice = task_nice(p);
1333 psinfo->pr_flag = p->flags;
1335 cred = __task_cred(p);
1336 SET_UID(psinfo->pr_uid, cred->uid);
1337 SET_GID(psinfo->pr_gid, cred->gid);
1339 strncpy(psinfo->pr_fname, p->comm, sizeof(psinfo->pr_fname));
1344 static void fill_auxv_note(struct memelfnote *note, struct mm_struct *mm)
1346 elf_addr_t *auxv = (elf_addr_t *) mm->saved_auxv;
1350 while (auxv[i - 2] != AT_NULL);
1351 fill_note(note, "CORE", NT_AUXV, i * sizeof(elf_addr_t), auxv);
1354 #ifdef CORE_DUMP_USE_REGSET
1355 #include <linux/regset.h>
1357 struct elf_thread_core_info {
1358 struct elf_thread_core_info *next;
1359 struct task_struct *task;
1360 struct elf_prstatus prstatus;
1361 struct memelfnote notes[0];
1364 struct elf_note_info {
1365 struct elf_thread_core_info *thread;
1366 struct memelfnote psinfo;
1367 struct memelfnote auxv;
1373 * When a regset has a writeback hook, we call it on each thread before
1374 * dumping user memory. On register window machines, this makes sure the
1375 * user memory backing the register data is up to date before we read it.
1377 static void do_thread_regset_writeback(struct task_struct *task,
1378 const struct user_regset *regset)
1380 if (regset->writeback)
1381 regset->writeback(task, regset, 1);
1384 static int fill_thread_core_info(struct elf_thread_core_info *t,
1385 const struct user_regset_view *view,
1386 long signr, size_t *total)
1391 * NT_PRSTATUS is the one special case, because the regset data
1392 * goes into the pr_reg field inside the note contents, rather
1393 * than being the whole note contents. We fill the reset in here.
1394 * We assume that regset 0 is NT_PRSTATUS.
1396 fill_prstatus(&t->prstatus, t->task, signr);
1397 (void) view->regsets[0].get(t->task, &view->regsets[0],
1398 0, sizeof(t->prstatus.pr_reg),
1399 &t->prstatus.pr_reg, NULL);
1401 fill_note(&t->notes[0], "CORE", NT_PRSTATUS,
1402 sizeof(t->prstatus), &t->prstatus);
1403 *total += notesize(&t->notes[0]);
1405 do_thread_regset_writeback(t->task, &view->regsets[0]);
1408 * Each other regset might generate a note too. For each regset
1409 * that has no core_note_type or is inactive, we leave t->notes[i]
1410 * all zero and we'll know to skip writing it later.
1412 for (i = 1; i < view->n; ++i) {
1413 const struct user_regset *regset = &view->regsets[i];
1414 do_thread_regset_writeback(t->task, regset);
1415 if (regset->core_note_type &&
1416 (!regset->active || regset->active(t->task, regset))) {
1418 size_t size = regset->n * regset->size;
1419 void *data = kmalloc(size, GFP_KERNEL);
1420 if (unlikely(!data))
1422 ret = regset->get(t->task, regset,
1423 0, size, data, NULL);
1427 if (regset->core_note_type != NT_PRFPREG)
1428 fill_note(&t->notes[i], "LINUX",
1429 regset->core_note_type,
1432 t->prstatus.pr_fpvalid = 1;
1433 fill_note(&t->notes[i], "CORE",
1434 NT_PRFPREG, size, data);
1436 *total += notesize(&t->notes[i]);
1444 static int fill_note_info(struct elfhdr *elf, int phdrs,
1445 struct elf_note_info *info,
1446 long signr, struct pt_regs *regs)
1448 struct task_struct *dump_task = current;
1449 const struct user_regset_view *view = task_user_regset_view(dump_task);
1450 struct elf_thread_core_info *t;
1451 struct elf_prpsinfo *psinfo;
1452 struct core_thread *ct;
1456 info->thread = NULL;
1458 psinfo = kmalloc(sizeof(*psinfo), GFP_KERNEL);
1462 fill_note(&info->psinfo, "CORE", NT_PRPSINFO, sizeof(*psinfo), psinfo);
1465 * Figure out how many notes we're going to need for each thread.
1467 info->thread_notes = 0;
1468 for (i = 0; i < view->n; ++i)
1469 if (view->regsets[i].core_note_type != 0)
1470 ++info->thread_notes;
1473 * Sanity check. We rely on regset 0 being in NT_PRSTATUS,
1474 * since it is our one special case.
1476 if (unlikely(info->thread_notes == 0) ||
1477 unlikely(view->regsets[0].core_note_type != NT_PRSTATUS)) {
1483 * Initialize the ELF file header.
1485 fill_elf_header(elf, phdrs,
1486 view->e_machine, view->e_flags, view->ei_osabi);
1489 * Allocate a structure for each thread.
1491 for (ct = &dump_task->mm->core_state->dumper; ct; ct = ct->next) {
1492 t = kzalloc(offsetof(struct elf_thread_core_info,
1493 notes[info->thread_notes]),
1499 if (ct->task == dump_task || !info->thread) {
1500 t->next = info->thread;
1504 * Make sure to keep the original task at
1505 * the head of the list.
1507 t->next = info->thread->next;
1508 info->thread->next = t;
1513 * Now fill in each thread's information.
1515 for (t = info->thread; t != NULL; t = t->next)
1516 if (!fill_thread_core_info(t, view, signr, &info->size))
1520 * Fill in the two process-wide notes.
1522 fill_psinfo(psinfo, dump_task->group_leader, dump_task->mm);
1523 info->size += notesize(&info->psinfo);
1525 fill_auxv_note(&info->auxv, current->mm);
1526 info->size += notesize(&info->auxv);
1531 static size_t get_note_info_size(struct elf_note_info *info)
1537 * Write all the notes for each thread. When writing the first thread, the
1538 * process-wide notes are interleaved after the first thread-specific note.
1540 static int write_note_info(struct elf_note_info *info,
1541 struct file *file, loff_t *foffset)
1544 struct elf_thread_core_info *t = info->thread;
1549 if (!writenote(&t->notes[0], file, foffset))
1552 if (first && !writenote(&info->psinfo, file, foffset))
1554 if (first && !writenote(&info->auxv, file, foffset))
1557 for (i = 1; i < info->thread_notes; ++i)
1558 if (t->notes[i].data &&
1559 !writenote(&t->notes[i], file, foffset))
1569 static void free_note_info(struct elf_note_info *info)
1571 struct elf_thread_core_info *threads = info->thread;
1574 struct elf_thread_core_info *t = threads;
1576 WARN_ON(t->notes[0].data && t->notes[0].data != &t->prstatus);
1577 for (i = 1; i < info->thread_notes; ++i)
1578 kfree(t->notes[i].data);
1581 kfree(info->psinfo.data);
1586 /* Here is the structure in which status of each thread is captured. */
1587 struct elf_thread_status
1589 struct list_head list;
1590 struct elf_prstatus prstatus; /* NT_PRSTATUS */
1591 elf_fpregset_t fpu; /* NT_PRFPREG */
1592 struct task_struct *thread;
1593 #ifdef ELF_CORE_COPY_XFPREGS
1594 elf_fpxregset_t xfpu; /* ELF_CORE_XFPREG_TYPE */
1596 struct memelfnote notes[3];
1601 * In order to add the specific thread information for the elf file format,
1602 * we need to keep a linked list of every threads pr_status and then create
1603 * a single section for them in the final core file.
1605 static int elf_dump_thread_status(long signr, struct elf_thread_status *t)
1608 struct task_struct *p = t->thread;
1611 fill_prstatus(&t->prstatus, p, signr);
1612 elf_core_copy_task_regs(p, &t->prstatus.pr_reg);
1614 fill_note(&t->notes[0], "CORE", NT_PRSTATUS, sizeof(t->prstatus),
1617 sz += notesize(&t->notes[0]);
1619 if ((t->prstatus.pr_fpvalid = elf_core_copy_task_fpregs(p, NULL,
1621 fill_note(&t->notes[1], "CORE", NT_PRFPREG, sizeof(t->fpu),
1624 sz += notesize(&t->notes[1]);
1627 #ifdef ELF_CORE_COPY_XFPREGS
1628 if (elf_core_copy_task_xfpregs(p, &t->xfpu)) {
1629 fill_note(&t->notes[2], "LINUX", ELF_CORE_XFPREG_TYPE,
1630 sizeof(t->xfpu), &t->xfpu);
1632 sz += notesize(&t->notes[2]);
1638 struct elf_note_info {
1639 struct memelfnote *notes;
1640 struct elf_prstatus *prstatus; /* NT_PRSTATUS */
1641 struct elf_prpsinfo *psinfo; /* NT_PRPSINFO */
1642 struct list_head thread_list;
1643 elf_fpregset_t *fpu;
1644 #ifdef ELF_CORE_COPY_XFPREGS
1645 elf_fpxregset_t *xfpu;
1647 int thread_status_size;
1651 static int elf_note_info_init(struct elf_note_info *info)
1653 memset(info, 0, sizeof(*info));
1654 INIT_LIST_HEAD(&info->thread_list);
1656 /* Allocate space for six ELF notes */
1657 info->notes = kmalloc(6 * sizeof(struct memelfnote), GFP_KERNEL);
1660 info->psinfo = kmalloc(sizeof(*info->psinfo), GFP_KERNEL);
1663 info->prstatus = kmalloc(sizeof(*info->prstatus), GFP_KERNEL);
1664 if (!info->prstatus)
1666 info->fpu = kmalloc(sizeof(*info->fpu), GFP_KERNEL);
1669 #ifdef ELF_CORE_COPY_XFPREGS
1670 info->xfpu = kmalloc(sizeof(*info->xfpu), GFP_KERNEL);
1675 #ifdef ELF_CORE_COPY_XFPREGS
1680 kfree(info->prstatus);
1682 kfree(info->psinfo);
1688 static int fill_note_info(struct elfhdr *elf, int phdrs,
1689 struct elf_note_info *info,
1690 long signr, struct pt_regs *regs)
1692 struct list_head *t;
1694 if (!elf_note_info_init(info))
1698 struct core_thread *ct;
1699 struct elf_thread_status *ets;
1701 for (ct = current->mm->core_state->dumper.next;
1702 ct; ct = ct->next) {
1703 ets = kzalloc(sizeof(*ets), GFP_KERNEL);
1707 ets->thread = ct->task;
1708 list_add(&ets->list, &info->thread_list);
1711 list_for_each(t, &info->thread_list) {
1714 ets = list_entry(t, struct elf_thread_status, list);
1715 sz = elf_dump_thread_status(signr, ets);
1716 info->thread_status_size += sz;
1719 /* now collect the dump for the current */
1720 memset(info->prstatus, 0, sizeof(*info->prstatus));
1721 fill_prstatus(info->prstatus, current, signr);
1722 elf_core_copy_regs(&info->prstatus->pr_reg, regs);
1725 fill_elf_header(elf, phdrs, ELF_ARCH, ELF_CORE_EFLAGS, ELF_OSABI);
1728 * Set up the notes in similar form to SVR4 core dumps made
1729 * with info from their /proc.
1732 fill_note(info->notes + 0, "CORE", NT_PRSTATUS,
1733 sizeof(*info->prstatus), info->prstatus);
1734 fill_psinfo(info->psinfo, current->group_leader, current->mm);
1735 fill_note(info->notes + 1, "CORE", NT_PRPSINFO,
1736 sizeof(*info->psinfo), info->psinfo);
1740 fill_auxv_note(&info->notes[info->numnote++], current->mm);
1742 /* Try to dump the FPU. */
1743 info->prstatus->pr_fpvalid = elf_core_copy_task_fpregs(current, regs,
1745 if (info->prstatus->pr_fpvalid)
1746 fill_note(info->notes + info->numnote++,
1747 "CORE", NT_PRFPREG, sizeof(*info->fpu), info->fpu);
1748 #ifdef ELF_CORE_COPY_XFPREGS
1749 if (elf_core_copy_task_xfpregs(current, info->xfpu))
1750 fill_note(info->notes + info->numnote++,
1751 "LINUX", ELF_CORE_XFPREG_TYPE,
1752 sizeof(*info->xfpu), info->xfpu);
1758 static size_t get_note_info_size(struct elf_note_info *info)
1763 for (i = 0; i < info->numnote; i++)
1764 sz += notesize(info->notes + i);
1766 sz += info->thread_status_size;
1771 static int write_note_info(struct elf_note_info *info,
1772 struct file *file, loff_t *foffset)
1775 struct list_head *t;
1777 for (i = 0; i < info->numnote; i++)
1778 if (!writenote(info->notes + i, file, foffset))
1781 /* write out the thread status notes section */
1782 list_for_each(t, &info->thread_list) {
1783 struct elf_thread_status *tmp =
1784 list_entry(t, struct elf_thread_status, list);
1786 for (i = 0; i < tmp->num_notes; i++)
1787 if (!writenote(&tmp->notes[i], file, foffset))
1794 static void free_note_info(struct elf_note_info *info)
1796 while (!list_empty(&info->thread_list)) {
1797 struct list_head *tmp = info->thread_list.next;
1799 kfree(list_entry(tmp, struct elf_thread_status, list));
1802 kfree(info->prstatus);
1803 kfree(info->psinfo);
1806 #ifdef ELF_CORE_COPY_XFPREGS
1813 static struct vm_area_struct *first_vma(struct task_struct *tsk,
1814 struct vm_area_struct *gate_vma)
1816 struct vm_area_struct *ret = tsk->mm->mmap;
1823 * Helper function for iterating across a vma list. It ensures that the caller
1824 * will visit `gate_vma' prior to terminating the search.
1826 static struct vm_area_struct *next_vma(struct vm_area_struct *this_vma,
1827 struct vm_area_struct *gate_vma)
1829 struct vm_area_struct *ret;
1831 ret = this_vma->vm_next;
1834 if (this_vma == gate_vma)
1839 static void fill_extnum_info(struct elfhdr *elf, struct elf_shdr *shdr4extnum,
1840 elf_addr_t e_shoff, int segs)
1842 elf->e_shoff = e_shoff;
1843 elf->e_shentsize = sizeof(*shdr4extnum);
1845 elf->e_shstrndx = SHN_UNDEF;
1847 memset(shdr4extnum, 0, sizeof(*shdr4extnum));
1849 shdr4extnum->sh_type = SHT_NULL;
1850 shdr4extnum->sh_size = elf->e_shnum;
1851 shdr4extnum->sh_link = elf->e_shstrndx;
1852 shdr4extnum->sh_info = segs;
1855 static size_t elf_core_vma_data_size(struct vm_area_struct *gate_vma,
1856 unsigned long mm_flags)
1858 struct vm_area_struct *vma;
1861 for (vma = first_vma(current, gate_vma); vma != NULL;
1862 vma = next_vma(vma, gate_vma))
1863 size += vma_dump_size(vma, mm_flags);
1870 * This is a two-pass process; first we find the offsets of the bits,
1871 * and then they are actually written out. If we run out of core limit
1874 static int elf_core_dump(struct coredump_params *cprm)
1880 struct vm_area_struct *vma, *gate_vma;
1881 struct elfhdr *elf = NULL;
1882 loff_t offset = 0, dataoff, foffset;
1883 struct elf_note_info info;
1884 struct elf_phdr *phdr4note = NULL;
1885 struct elf_shdr *shdr4extnum = NULL;
1890 * We no longer stop all VM operations.
1892 * This is because those proceses that could possibly change map_count
1893 * or the mmap / vma pages are now blocked in do_exit on current
1894 * finishing this core dump.
1896 * Only ptrace can touch these memory addresses, but it doesn't change
1897 * the map_count or the pages allocated. So no possibility of crashing
1898 * exists while dumping the mm->vm_next areas to the core file.
1901 /* alloc memory for large data structures: too large to be on stack */
1902 elf = kmalloc(sizeof(*elf), GFP_KERNEL);
1906 * The number of segs are recored into ELF header as 16bit value.
1907 * Please check DEFAULT_MAX_MAP_COUNT definition when you modify here.
1909 segs = current->mm->map_count;
1910 segs += elf_core_extra_phdrs();
1912 gate_vma = get_gate_vma(current->mm);
1913 if (gate_vma != NULL)
1916 /* for notes section */
1919 /* If segs > PN_XNUM(0xffff), then e_phnum overflows. To avoid
1920 * this, kernel supports extended numbering. Have a look at
1921 * include/linux/elf.h for further information. */
1922 e_phnum = segs > PN_XNUM ? PN_XNUM : segs;
1925 * Collect all the non-memory information about the process for the
1926 * notes. This also sets up the file header.
1928 if (!fill_note_info(elf, e_phnum, &info, cprm->signr, cprm->regs))
1932 current->flags |= PF_DUMPCORE;
1937 offset += sizeof(*elf); /* Elf header */
1938 offset += segs * sizeof(struct elf_phdr); /* Program headers */
1941 /* Write notes phdr entry */
1943 size_t sz = get_note_info_size(&info);
1945 sz += elf_coredump_extra_notes_size();
1947 phdr4note = kmalloc(sizeof(*phdr4note), GFP_KERNEL);
1951 fill_elf_note_phdr(phdr4note, sz, offset);
1955 dataoff = offset = roundup(offset, ELF_EXEC_PAGESIZE);
1957 offset += elf_core_vma_data_size(gate_vma, cprm->mm_flags);
1958 offset += elf_core_extra_data_size();
1961 if (e_phnum == PN_XNUM) {
1962 shdr4extnum = kmalloc(sizeof(*shdr4extnum), GFP_KERNEL);
1965 fill_extnum_info(elf, shdr4extnum, e_shoff, segs);
1970 size += sizeof(*elf);
1971 if (size > cprm->limit || !dump_write(cprm->file, elf, sizeof(*elf)))
1974 size += sizeof(*phdr4note);
1975 if (size > cprm->limit
1976 || !dump_write(cprm->file, phdr4note, sizeof(*phdr4note)))
1979 /* Write program headers for segments dump */
1980 for (vma = first_vma(current, gate_vma); vma != NULL;
1981 vma = next_vma(vma, gate_vma)) {
1982 struct elf_phdr phdr;
1984 phdr.p_type = PT_LOAD;
1985 phdr.p_offset = offset;
1986 phdr.p_vaddr = vma->vm_start;
1988 phdr.p_filesz = vma_dump_size(vma, cprm->mm_flags);
1989 phdr.p_memsz = vma->vm_end - vma->vm_start;
1990 offset += phdr.p_filesz;
1991 phdr.p_flags = vma->vm_flags & VM_READ ? PF_R : 0;
1992 if (vma->vm_flags & VM_WRITE)
1993 phdr.p_flags |= PF_W;
1994 if (vma->vm_flags & VM_EXEC)
1995 phdr.p_flags |= PF_X;
1996 phdr.p_align = ELF_EXEC_PAGESIZE;
1998 size += sizeof(phdr);
1999 if (size > cprm->limit
2000 || !dump_write(cprm->file, &phdr, sizeof(phdr)))
2004 if (!elf_core_write_extra_phdrs(cprm->file, offset, &size, cprm->limit))
2007 /* write out the notes section */
2008 if (!write_note_info(&info, cprm->file, &foffset))
2011 if (elf_coredump_extra_notes_write(cprm->file, &foffset))
2015 if (!dump_seek(cprm->file, dataoff - foffset))
2018 for (vma = first_vma(current, gate_vma); vma != NULL;
2019 vma = next_vma(vma, gate_vma)) {
2023 end = vma->vm_start + vma_dump_size(vma, cprm->mm_flags);
2025 for (addr = vma->vm_start; addr < end; addr += PAGE_SIZE) {
2029 page = get_dump_page(addr);
2031 void *kaddr = kmap(page);
2032 stop = ((size += PAGE_SIZE) > cprm->limit) ||
2033 !dump_write(cprm->file, kaddr,
2036 page_cache_release(page);
2038 stop = !dump_seek(cprm->file, PAGE_SIZE);
2044 if (!elf_core_write_extra_data(cprm->file, &size, cprm->limit))
2047 if (e_phnum == PN_XNUM) {
2048 size += sizeof(*shdr4extnum);
2049 if (size > cprm->limit
2050 || !dump_write(cprm->file, shdr4extnum,
2051 sizeof(*shdr4extnum)))
2059 free_note_info(&info);
2067 #endif /* CONFIG_ELF_CORE */
2069 static int __init init_elf_binfmt(void)
2071 return register_binfmt(&elf_format);
2074 static void __exit exit_elf_binfmt(void)
2076 /* Remove the COFF and ELF loaders. */
2077 unregister_binfmt(&elf_format);
2080 core_initcall(init_elf_binfmt);
2081 module_exit(exit_elf_binfmt);
2082 MODULE_LICENSE("GPL");