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>
15 #include <linux/stat.h>
16 #include <linux/time.h>
18 #include <linux/mman.h>
19 #include <linux/errno.h>
20 #include <linux/signal.h>
21 #include <linux/binfmts.h>
22 #include <linux/string.h>
23 #include <linux/file.h>
24 #include <linux/fcntl.h>
25 #include <linux/ptrace.h>
26 #include <linux/slab.h>
27 #include <linux/shm.h>
28 #include <linux/personality.h>
29 #include <linux/elfcore.h>
30 #include <linux/init.h>
31 #include <linux/highuid.h>
32 #include <linux/smp.h>
33 #include <linux/compiler.h>
34 #include <linux/highmem.h>
35 #include <linux/pagemap.h>
36 #include <linux/security.h>
37 #include <linux/syscalls.h>
38 #include <linux/random.h>
39 #include <linux/elf.h>
40 #include <linux/utsname.h>
41 #include <asm/uaccess.h>
42 #include <asm/param.h>
45 static int load_elf_binary(struct linux_binprm *bprm, struct pt_regs *regs);
46 static int load_elf_library(struct file *);
47 static unsigned long elf_map(struct file *, unsigned long, struct elf_phdr *,
48 int, int, unsigned long);
51 * If we don't support core dumping, then supply a NULL so we
54 #if defined(USE_ELF_CORE_DUMP) && defined(CONFIG_ELF_CORE)
55 static int elf_core_dump(long signr, struct pt_regs *regs, struct file *file, unsigned long limit);
57 #define elf_core_dump NULL
60 #if ELF_EXEC_PAGESIZE > PAGE_SIZE
61 #define ELF_MIN_ALIGN ELF_EXEC_PAGESIZE
63 #define ELF_MIN_ALIGN PAGE_SIZE
66 #ifndef ELF_CORE_EFLAGS
67 #define ELF_CORE_EFLAGS 0
70 #define ELF_PAGESTART(_v) ((_v) & ~(unsigned long)(ELF_MIN_ALIGN-1))
71 #define ELF_PAGEOFFSET(_v) ((_v) & (ELF_MIN_ALIGN-1))
72 #define ELF_PAGEALIGN(_v) (((_v) + ELF_MIN_ALIGN - 1) & ~(ELF_MIN_ALIGN - 1))
74 static struct linux_binfmt elf_format = {
75 .module = THIS_MODULE,
76 .load_binary = load_elf_binary,
77 .load_shlib = load_elf_library,
78 .core_dump = elf_core_dump,
79 .min_coredump = ELF_EXEC_PAGESIZE,
83 #define BAD_ADDR(x) ((unsigned long)(x) >= TASK_SIZE)
85 static int set_brk(unsigned long start, unsigned long end)
87 start = ELF_PAGEALIGN(start);
88 end = ELF_PAGEALIGN(end);
91 down_write(¤t->mm->mmap_sem);
92 addr = do_brk(start, end - start);
93 up_write(¤t->mm->mmap_sem);
97 current->mm->start_brk = current->mm->brk = end;
101 /* We need to explicitly zero any fractional pages
102 after the data section (i.e. bss). This would
103 contain the junk from the file that should not
106 static int padzero(unsigned long elf_bss)
110 nbyte = ELF_PAGEOFFSET(elf_bss);
112 nbyte = ELF_MIN_ALIGN - nbyte;
113 if (clear_user((void __user *) elf_bss, nbyte))
119 /* Let's use some macros to make this stack manipulation a little clearer */
120 #ifdef CONFIG_STACK_GROWSUP
121 #define STACK_ADD(sp, items) ((elf_addr_t __user *)(sp) + (items))
122 #define STACK_ROUND(sp, items) \
123 ((15 + (unsigned long) ((sp) + (items))) &~ 15UL)
124 #define STACK_ALLOC(sp, len) ({ \
125 elf_addr_t __user *old_sp = (elf_addr_t __user *)sp; sp += len; \
128 #define STACK_ADD(sp, items) ((elf_addr_t __user *)(sp) - (items))
129 #define STACK_ROUND(sp, items) \
130 (((unsigned long) (sp - items)) &~ 15UL)
131 #define STACK_ALLOC(sp, len) ({ sp -= len ; sp; })
134 #ifndef ELF_BASE_PLATFORM
136 * AT_BASE_PLATFORM indicates the "real" hardware/microarchitecture.
137 * If the arch defines ELF_BASE_PLATFORM (in asm/elf.h), the value
138 * will be copied to the user stack in the same manner as AT_PLATFORM.
140 #define ELF_BASE_PLATFORM NULL
144 create_elf_tables(struct linux_binprm *bprm, struct elfhdr *exec,
145 unsigned long load_addr, unsigned long interp_load_addr)
147 unsigned long p = bprm->p;
148 int argc = bprm->argc;
149 int envc = bprm->envc;
150 elf_addr_t __user *argv;
151 elf_addr_t __user *envp;
152 elf_addr_t __user *sp;
153 elf_addr_t __user *u_platform;
154 elf_addr_t __user *u_base_platform;
155 const char *k_platform = ELF_PLATFORM;
156 const char *k_base_platform = ELF_BASE_PLATFORM;
158 elf_addr_t *elf_info;
160 struct task_struct *tsk = current;
161 struct vm_area_struct *vma;
164 * In some cases (e.g. Hyper-Threading), we want to avoid L1
165 * evictions by the processes running on the same package. One
166 * thing we can do is to shuffle the initial stack for them.
169 p = arch_align_stack(p);
172 * If this architecture has a platform capability string, copy it
173 * to userspace. In some cases (Sparc), this info is impossible
174 * for userspace to get any other way, in others (i386) it is
179 size_t len = strlen(k_platform) + 1;
181 u_platform = (elf_addr_t __user *)STACK_ALLOC(p, len);
182 if (__copy_to_user(u_platform, k_platform, len))
187 * If this architecture has a "base" platform capability
188 * string, copy it to userspace.
190 u_base_platform = NULL;
191 if (k_base_platform) {
192 size_t len = strlen(k_base_platform) + 1;
194 u_base_platform = (elf_addr_t __user *)STACK_ALLOC(p, len);
195 if (__copy_to_user(u_base_platform, k_base_platform, len))
199 /* Create the ELF interpreter info */
200 elf_info = (elf_addr_t *)current->mm->saved_auxv;
201 /* update AT_VECTOR_SIZE_BASE if the number of NEW_AUX_ENT() changes */
202 #define NEW_AUX_ENT(id, val) \
204 elf_info[ei_index++] = id; \
205 elf_info[ei_index++] = val; \
210 * ARCH_DLINFO must come first so PPC can do its special alignment of
212 * update AT_VECTOR_SIZE_ARCH if the number of NEW_AUX_ENT() in
213 * ARCH_DLINFO changes
217 NEW_AUX_ENT(AT_HWCAP, ELF_HWCAP);
218 NEW_AUX_ENT(AT_PAGESZ, ELF_EXEC_PAGESIZE);
219 NEW_AUX_ENT(AT_CLKTCK, CLOCKS_PER_SEC);
220 NEW_AUX_ENT(AT_PHDR, load_addr + exec->e_phoff);
221 NEW_AUX_ENT(AT_PHENT, sizeof(struct elf_phdr));
222 NEW_AUX_ENT(AT_PHNUM, exec->e_phnum);
223 NEW_AUX_ENT(AT_BASE, interp_load_addr);
224 NEW_AUX_ENT(AT_FLAGS, 0);
225 NEW_AUX_ENT(AT_ENTRY, exec->e_entry);
226 NEW_AUX_ENT(AT_UID, tsk->uid);
227 NEW_AUX_ENT(AT_EUID, tsk->euid);
228 NEW_AUX_ENT(AT_GID, tsk->gid);
229 NEW_AUX_ENT(AT_EGID, tsk->egid);
230 NEW_AUX_ENT(AT_SECURE, security_bprm_secureexec(bprm));
231 NEW_AUX_ENT(AT_EXECFN, bprm->exec);
233 NEW_AUX_ENT(AT_PLATFORM,
234 (elf_addr_t)(unsigned long)u_platform);
236 if (k_base_platform) {
237 NEW_AUX_ENT(AT_BASE_PLATFORM,
238 (elf_addr_t)(unsigned long)u_base_platform);
240 if (bprm->interp_flags & BINPRM_FLAGS_EXECFD) {
241 NEW_AUX_ENT(AT_EXECFD, bprm->interp_data);
244 /* AT_NULL is zero; clear the rest too */
245 memset(&elf_info[ei_index], 0,
246 sizeof current->mm->saved_auxv - ei_index * sizeof elf_info[0]);
248 /* And advance past the AT_NULL entry. */
251 sp = STACK_ADD(p, ei_index);
253 items = (argc + 1) + (envc + 1) + 1;
254 bprm->p = STACK_ROUND(sp, items);
256 /* Point sp at the lowest address on the stack */
257 #ifdef CONFIG_STACK_GROWSUP
258 sp = (elf_addr_t __user *)bprm->p - items - ei_index;
259 bprm->exec = (unsigned long)sp; /* XXX: PARISC HACK */
261 sp = (elf_addr_t __user *)bprm->p;
266 * Grow the stack manually; some architectures have a limit on how
267 * far ahead a user-space access may be in order to grow the stack.
269 vma = find_extend_vma(current->mm, bprm->p);
273 /* Now, let's put argc (and argv, envp if appropriate) on the stack */
274 if (__put_user(argc, sp++))
277 envp = argv + argc + 1;
279 /* Populate argv and envp */
280 p = current->mm->arg_end = current->mm->arg_start;
283 if (__put_user((elf_addr_t)p, argv++))
285 len = strnlen_user((void __user *)p, MAX_ARG_STRLEN);
286 if (!len || len > MAX_ARG_STRLEN)
290 if (__put_user(0, argv))
292 current->mm->arg_end = current->mm->env_start = p;
295 if (__put_user((elf_addr_t)p, envp++))
297 len = strnlen_user((void __user *)p, MAX_ARG_STRLEN);
298 if (!len || len > MAX_ARG_STRLEN)
302 if (__put_user(0, envp))
304 current->mm->env_end = p;
306 /* Put the elf_info on the stack in the right place. */
307 sp = (elf_addr_t __user *)envp + 1;
308 if (copy_to_user(sp, elf_info, ei_index * sizeof(elf_addr_t)))
315 static unsigned long elf_map(struct file *filep, unsigned long addr,
316 struct elf_phdr *eppnt, int prot, int type,
317 unsigned long total_size)
319 unsigned long map_addr;
320 unsigned long size = eppnt->p_filesz + ELF_PAGEOFFSET(eppnt->p_vaddr);
321 unsigned long off = eppnt->p_offset - ELF_PAGEOFFSET(eppnt->p_vaddr);
322 addr = ELF_PAGESTART(addr);
323 size = ELF_PAGEALIGN(size);
325 /* mmap() will return -EINVAL if given a zero size, but a
326 * segment with zero filesize is perfectly valid */
330 down_write(¤t->mm->mmap_sem);
332 * total_size is the size of the ELF (interpreter) image.
333 * The _first_ mmap needs to know the full size, otherwise
334 * randomization might put this image into an overlapping
335 * position with the ELF binary image. (since size < total_size)
336 * So we first map the 'big' image - and unmap the remainder at
337 * the end. (which unmap is needed for ELF images with holes.)
340 total_size = ELF_PAGEALIGN(total_size);
341 map_addr = do_mmap(filep, addr, total_size, prot, type, off);
342 if (!BAD_ADDR(map_addr))
343 do_munmap(current->mm, map_addr+size, total_size-size);
345 map_addr = do_mmap(filep, addr, size, prot, type, off);
347 up_write(¤t->mm->mmap_sem);
351 #endif /* !elf_map */
353 static unsigned long total_mapping_size(struct elf_phdr *cmds, int nr)
355 int i, first_idx = -1, last_idx = -1;
357 for (i = 0; i < nr; i++) {
358 if (cmds[i].p_type == PT_LOAD) {
367 return cmds[last_idx].p_vaddr + cmds[last_idx].p_memsz -
368 ELF_PAGESTART(cmds[first_idx].p_vaddr);
372 /* This is much more generalized than the library routine read function,
373 so we keep this separate. Technically the library read function
374 is only provided so that we can read a.out libraries that have
377 static unsigned long load_elf_interp(struct elfhdr *interp_elf_ex,
378 struct file *interpreter, unsigned long *interp_map_addr,
379 unsigned long no_base)
381 struct elf_phdr *elf_phdata;
382 struct elf_phdr *eppnt;
383 unsigned long load_addr = 0;
384 int load_addr_set = 0;
385 unsigned long last_bss = 0, elf_bss = 0;
386 unsigned long error = ~0UL;
387 unsigned long total_size;
390 /* First of all, some simple consistency checks */
391 if (interp_elf_ex->e_type != ET_EXEC &&
392 interp_elf_ex->e_type != ET_DYN)
394 if (!elf_check_arch(interp_elf_ex))
396 if (!interpreter->f_op || !interpreter->f_op->mmap)
400 * If the size of this structure has changed, then punt, since
401 * we will be doing the wrong thing.
403 if (interp_elf_ex->e_phentsize != sizeof(struct elf_phdr))
405 if (interp_elf_ex->e_phnum < 1 ||
406 interp_elf_ex->e_phnum > 65536U / sizeof(struct elf_phdr))
409 /* Now read in all of the header information */
410 size = sizeof(struct elf_phdr) * interp_elf_ex->e_phnum;
411 if (size > ELF_MIN_ALIGN)
413 elf_phdata = kmalloc(size, GFP_KERNEL);
417 retval = kernel_read(interpreter, interp_elf_ex->e_phoff,
418 (char *)elf_phdata,size);
420 if (retval != size) {
426 total_size = total_mapping_size(elf_phdata, interp_elf_ex->e_phnum);
433 for (i = 0; i < interp_elf_ex->e_phnum; i++, eppnt++) {
434 if (eppnt->p_type == PT_LOAD) {
435 int elf_type = MAP_PRIVATE | MAP_DENYWRITE;
437 unsigned long vaddr = 0;
438 unsigned long k, map_addr;
440 if (eppnt->p_flags & PF_R)
441 elf_prot = PROT_READ;
442 if (eppnt->p_flags & PF_W)
443 elf_prot |= PROT_WRITE;
444 if (eppnt->p_flags & PF_X)
445 elf_prot |= PROT_EXEC;
446 vaddr = eppnt->p_vaddr;
447 if (interp_elf_ex->e_type == ET_EXEC || load_addr_set)
448 elf_type |= MAP_FIXED;
449 else if (no_base && interp_elf_ex->e_type == ET_DYN)
452 map_addr = elf_map(interpreter, load_addr + vaddr,
453 eppnt, elf_prot, elf_type, total_size);
455 if (!*interp_map_addr)
456 *interp_map_addr = map_addr;
458 if (BAD_ADDR(map_addr))
461 if (!load_addr_set &&
462 interp_elf_ex->e_type == ET_DYN) {
463 load_addr = map_addr - ELF_PAGESTART(vaddr);
468 * Check to see if the section's size will overflow the
469 * allowed task size. Note that p_filesz must always be
470 * <= p_memsize so it's only necessary to check p_memsz.
472 k = load_addr + eppnt->p_vaddr;
474 eppnt->p_filesz > eppnt->p_memsz ||
475 eppnt->p_memsz > TASK_SIZE ||
476 TASK_SIZE - eppnt->p_memsz < k) {
482 * Find the end of the file mapping for this phdr, and
483 * keep track of the largest address we see for this.
485 k = load_addr + eppnt->p_vaddr + eppnt->p_filesz;
490 * Do the same thing for the memory mapping - between
491 * elf_bss and last_bss is the bss section.
493 k = load_addr + eppnt->p_memsz + eppnt->p_vaddr;
500 * Now fill out the bss section. First pad the last page up
501 * to the page boundary, and then perform a mmap to make sure
502 * that there are zero-mapped pages up to and including the
505 if (padzero(elf_bss)) {
510 /* What we have mapped so far */
511 elf_bss = ELF_PAGESTART(elf_bss + ELF_MIN_ALIGN - 1);
513 /* Map the last of the bss segment */
514 if (last_bss > elf_bss) {
515 down_write(¤t->mm->mmap_sem);
516 error = do_brk(elf_bss, last_bss - elf_bss);
517 up_write(¤t->mm->mmap_sem);
531 * These are the functions used to load ELF style executables and shared
532 * libraries. There is no binary dependent code anywhere else.
535 #define INTERPRETER_NONE 0
536 #define INTERPRETER_ELF 2
538 #ifndef STACK_RND_MASK
539 #define STACK_RND_MASK (0x7ff >> (PAGE_SHIFT - 12)) /* 8MB of VA */
542 static unsigned long randomize_stack_top(unsigned long stack_top)
544 unsigned int random_variable = 0;
546 if ((current->flags & PF_RANDOMIZE) &&
547 !(current->personality & ADDR_NO_RANDOMIZE)) {
548 random_variable = get_random_int() & STACK_RND_MASK;
549 random_variable <<= PAGE_SHIFT;
551 #ifdef CONFIG_STACK_GROWSUP
552 return PAGE_ALIGN(stack_top) + random_variable;
554 return PAGE_ALIGN(stack_top) - random_variable;
558 static int load_elf_binary(struct linux_binprm *bprm, struct pt_regs *regs)
560 struct file *interpreter = NULL; /* to shut gcc up */
561 unsigned long load_addr = 0, load_bias = 0;
562 int load_addr_set = 0;
563 char * elf_interpreter = NULL;
565 struct elf_phdr *elf_ppnt, *elf_phdata;
566 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 = 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 retval = get_unused_fd();
625 get_file(bprm->file);
626 fd_install(elf_exec_fileno = retval, bprm->file);
628 elf_ppnt = elf_phdata;
637 for (i = 0; i < loc->elf_ex.e_phnum; i++) {
638 if (elf_ppnt->p_type == PT_INTERP) {
639 /* This is the program interpreter used for
640 * shared libraries - for now assume that this
641 * is an a.out format binary
644 if (elf_ppnt->p_filesz > PATH_MAX ||
645 elf_ppnt->p_filesz < 2)
649 elf_interpreter = kmalloc(elf_ppnt->p_filesz,
651 if (!elf_interpreter)
654 retval = kernel_read(bprm->file, elf_ppnt->p_offset,
657 if (retval != elf_ppnt->p_filesz) {
660 goto out_free_interp;
662 /* make sure path is NULL terminated */
664 if (elf_interpreter[elf_ppnt->p_filesz - 1] != '\0')
665 goto out_free_interp;
668 * The early SET_PERSONALITY here is so that the lookup
669 * for the interpreter happens in the namespace of the
670 * to-be-execed image. SET_PERSONALITY can select an
673 * However, SET_PERSONALITY is NOT allowed to switch
674 * this task into the new images's memory mapping
675 * policy - that is, TASK_SIZE must still evaluate to
676 * that which is appropriate to the execing application.
677 * This is because exit_mmap() needs to have TASK_SIZE
678 * evaluate to the size of the old image.
680 * So if (say) a 64-bit application is execing a 32-bit
681 * application it is the architecture's responsibility
682 * to defer changing the value of TASK_SIZE until the
683 * switch really is going to happen - do this in
684 * flush_thread(). - akpm
686 SET_PERSONALITY(loc->elf_ex, 0);
688 interpreter = open_exec(elf_interpreter);
689 retval = PTR_ERR(interpreter);
690 if (IS_ERR(interpreter))
691 goto out_free_interp;
694 * If the binary is not readable then enforce
695 * mm->dumpable = 0 regardless of the interpreter's
698 if (file_permission(interpreter, MAY_READ) < 0)
699 bprm->interp_flags |= BINPRM_FLAGS_ENFORCE_NONDUMP;
701 retval = kernel_read(interpreter, 0, bprm->buf,
703 if (retval != BINPRM_BUF_SIZE) {
706 goto out_free_dentry;
709 /* Get the exec headers */
710 loc->interp_elf_ex = *((struct elfhdr *)bprm->buf);
716 elf_ppnt = elf_phdata;
717 for (i = 0; i < loc->elf_ex.e_phnum; i++, elf_ppnt++)
718 if (elf_ppnt->p_type == PT_GNU_STACK) {
719 if (elf_ppnt->p_flags & PF_X)
720 executable_stack = EXSTACK_ENABLE_X;
722 executable_stack = EXSTACK_DISABLE_X;
726 /* Some simple consistency checks for the interpreter */
727 if (elf_interpreter) {
729 /* Not an ELF interpreter */
730 if (memcmp(loc->interp_elf_ex.e_ident, ELFMAG, SELFMAG) != 0)
731 goto out_free_dentry;
732 /* Verify the interpreter has a valid arch */
733 if (!elf_check_arch(&loc->interp_elf_ex))
734 goto out_free_dentry;
736 /* Executables without an interpreter also need a personality */
737 SET_PERSONALITY(loc->elf_ex, 0);
740 /* Flush all traces of the currently running executable */
741 retval = flush_old_exec(bprm);
743 goto out_free_dentry;
745 /* OK, This is the point of no return */
746 current->flags &= ~PF_FORKNOEXEC;
747 current->mm->def_flags = def_flags;
749 /* Do this immediately, since STACK_TOP as used in setup_arg_pages
750 may depend on the personality. */
751 SET_PERSONALITY(loc->elf_ex, 0);
752 if (elf_read_implies_exec(loc->elf_ex, executable_stack))
753 current->personality |= READ_IMPLIES_EXEC;
755 if (!(current->personality & ADDR_NO_RANDOMIZE) && randomize_va_space)
756 current->flags |= PF_RANDOMIZE;
757 arch_pick_mmap_layout(current->mm);
759 /* Do this so that we can load the interpreter, if need be. We will
760 change some of these later */
761 current->mm->free_area_cache = current->mm->mmap_base;
762 current->mm->cached_hole_size = 0;
763 retval = setup_arg_pages(bprm, randomize_stack_top(STACK_TOP),
766 send_sig(SIGKILL, current, 0);
767 goto out_free_dentry;
770 current->mm->start_stack = bprm->p;
772 /* Now we do a little grungy work by mmaping the ELF image into
773 the correct location in memory. */
774 for(i = 0, elf_ppnt = elf_phdata;
775 i < loc->elf_ex.e_phnum; i++, elf_ppnt++) {
776 int elf_prot = 0, elf_flags;
777 unsigned long k, vaddr;
779 if (elf_ppnt->p_type != PT_LOAD)
782 if (unlikely (elf_brk > elf_bss)) {
785 /* There was a PT_LOAD segment with p_memsz > p_filesz
786 before this one. Map anonymous pages, if needed,
787 and clear the area. */
788 retval = set_brk (elf_bss + load_bias,
789 elf_brk + load_bias);
791 send_sig(SIGKILL, current, 0);
792 goto out_free_dentry;
794 nbyte = ELF_PAGEOFFSET(elf_bss);
796 nbyte = ELF_MIN_ALIGN - nbyte;
797 if (nbyte > elf_brk - elf_bss)
798 nbyte = elf_brk - elf_bss;
799 if (clear_user((void __user *)elf_bss +
802 * This bss-zeroing can fail if the ELF
803 * file specifies odd protections. So
804 * we don't check the return value
810 if (elf_ppnt->p_flags & PF_R)
811 elf_prot |= PROT_READ;
812 if (elf_ppnt->p_flags & PF_W)
813 elf_prot |= PROT_WRITE;
814 if (elf_ppnt->p_flags & PF_X)
815 elf_prot |= PROT_EXEC;
817 elf_flags = MAP_PRIVATE | MAP_DENYWRITE | MAP_EXECUTABLE;
819 vaddr = elf_ppnt->p_vaddr;
820 if (loc->elf_ex.e_type == ET_EXEC || load_addr_set) {
821 elf_flags |= MAP_FIXED;
822 } else if (loc->elf_ex.e_type == ET_DYN) {
823 /* Try and get dynamic programs out of the way of the
824 * default mmap base, as well as whatever program they
825 * might try to exec. This is because the brk will
826 * follow the loader, and is not movable. */
830 load_bias = ELF_PAGESTART(ELF_ET_DYN_BASE - vaddr);
834 error = elf_map(bprm->file, load_bias + vaddr, elf_ppnt,
835 elf_prot, elf_flags, 0);
836 if (BAD_ADDR(error)) {
837 send_sig(SIGKILL, current, 0);
838 retval = IS_ERR((void *)error) ?
839 PTR_ERR((void*)error) : -EINVAL;
840 goto out_free_dentry;
843 if (!load_addr_set) {
845 load_addr = (elf_ppnt->p_vaddr - elf_ppnt->p_offset);
846 if (loc->elf_ex.e_type == ET_DYN) {
848 ELF_PAGESTART(load_bias + vaddr);
849 load_addr += load_bias;
850 reloc_func_desc = load_bias;
853 k = elf_ppnt->p_vaddr;
860 * Check to see if the section's size will overflow the
861 * allowed task size. Note that p_filesz must always be
862 * <= p_memsz so it is only necessary to check p_memsz.
864 if (BAD_ADDR(k) || elf_ppnt->p_filesz > elf_ppnt->p_memsz ||
865 elf_ppnt->p_memsz > TASK_SIZE ||
866 TASK_SIZE - elf_ppnt->p_memsz < k) {
867 /* set_brk can never work. Avoid overflows. */
868 send_sig(SIGKILL, current, 0);
870 goto out_free_dentry;
873 k = elf_ppnt->p_vaddr + elf_ppnt->p_filesz;
877 if ((elf_ppnt->p_flags & PF_X) && end_code < k)
881 k = elf_ppnt->p_vaddr + elf_ppnt->p_memsz;
886 loc->elf_ex.e_entry += load_bias;
887 elf_bss += load_bias;
888 elf_brk += load_bias;
889 start_code += load_bias;
890 end_code += load_bias;
891 start_data += load_bias;
892 end_data += load_bias;
894 /* Calling set_brk effectively mmaps the pages that we need
895 * for the bss and break sections. We must do this before
896 * mapping in the interpreter, to make sure it doesn't wind
897 * up getting placed where the bss needs to go.
899 retval = set_brk(elf_bss, elf_brk);
901 send_sig(SIGKILL, current, 0);
902 goto out_free_dentry;
904 if (likely(elf_bss != elf_brk) && unlikely(padzero(elf_bss))) {
905 send_sig(SIGSEGV, current, 0);
906 retval = -EFAULT; /* Nobody gets to see this, but.. */
907 goto out_free_dentry;
910 if (elf_interpreter) {
911 unsigned long uninitialized_var(interp_map_addr);
913 elf_entry = load_elf_interp(&loc->interp_elf_ex,
917 if (!IS_ERR((void *)elf_entry)) {
919 * load_elf_interp() returns relocation
922 interp_load_addr = elf_entry;
923 elf_entry += loc->interp_elf_ex.e_entry;
925 if (BAD_ADDR(elf_entry)) {
926 force_sig(SIGSEGV, current);
927 retval = IS_ERR((void *)elf_entry) ?
928 (int)elf_entry : -EINVAL;
929 goto out_free_dentry;
931 reloc_func_desc = interp_load_addr;
933 allow_write_access(interpreter);
935 kfree(elf_interpreter);
937 elf_entry = loc->elf_ex.e_entry;
938 if (BAD_ADDR(elf_entry)) {
939 force_sig(SIGSEGV, current);
941 goto out_free_dentry;
947 sys_close(elf_exec_fileno);
949 set_binfmt(&elf_format);
951 #ifdef ARCH_HAS_SETUP_ADDITIONAL_PAGES
952 retval = arch_setup_additional_pages(bprm, executable_stack);
954 send_sig(SIGKILL, current, 0);
957 #endif /* ARCH_HAS_SETUP_ADDITIONAL_PAGES */
960 current->flags &= ~PF_FORKNOEXEC;
961 retval = create_elf_tables(bprm, &loc->elf_ex,
962 load_addr, interp_load_addr);
964 send_sig(SIGKILL, current, 0);
967 /* N.B. passed_fileno might not be initialized? */
968 current->mm->end_code = end_code;
969 current->mm->start_code = start_code;
970 current->mm->start_data = start_data;
971 current->mm->end_data = end_data;
972 current->mm->start_stack = bprm->p;
974 #ifdef arch_randomize_brk
975 if ((current->flags & PF_RANDOMIZE) && (randomize_va_space > 1))
976 current->mm->brk = current->mm->start_brk =
977 arch_randomize_brk(current->mm);
980 if (current->personality & MMAP_PAGE_ZERO) {
981 /* Why this, you ask??? Well SVr4 maps page 0 as read-only,
982 and some applications "depend" upon this behavior.
983 Since we do not have the power to recompile these, we
984 emulate the SVr4 behavior. Sigh. */
985 down_write(¤t->mm->mmap_sem);
986 error = do_mmap(NULL, 0, PAGE_SIZE, PROT_READ | PROT_EXEC,
987 MAP_FIXED | MAP_PRIVATE, 0);
988 up_write(¤t->mm->mmap_sem);
993 * The ABI may specify that certain registers be set up in special
994 * ways (on i386 %edx is the address of a DT_FINI function, for
995 * example. In addition, it may also specify (eg, PowerPC64 ELF)
996 * that the e_entry field is the address of the function descriptor
997 * for the startup routine, rather than the address of the startup
998 * routine itself. This macro performs whatever initialization to
999 * the regs structure is required as well as any relocations to the
1000 * function descriptor entries when executing dynamically links apps.
1002 ELF_PLAT_INIT(regs, reloc_func_desc);
1005 start_thread(regs, elf_entry, bprm->p);
1014 allow_write_access(interpreter);
1018 kfree(elf_interpreter);
1020 sys_close(elf_exec_fileno);
1026 /* This is really simpleminded and specialized - we are loading an
1027 a.out library that is given an ELF header. */
1028 static int load_elf_library(struct file *file)
1030 struct elf_phdr *elf_phdata;
1031 struct elf_phdr *eppnt;
1032 unsigned long elf_bss, bss, len;
1033 int retval, error, i, j;
1034 struct elfhdr elf_ex;
1037 retval = kernel_read(file, 0, (char *)&elf_ex, sizeof(elf_ex));
1038 if (retval != sizeof(elf_ex))
1041 if (memcmp(elf_ex.e_ident, ELFMAG, SELFMAG) != 0)
1044 /* First of all, some simple consistency checks */
1045 if (elf_ex.e_type != ET_EXEC || elf_ex.e_phnum > 2 ||
1046 !elf_check_arch(&elf_ex) || !file->f_op || !file->f_op->mmap)
1049 /* Now read in all of the header information */
1051 j = sizeof(struct elf_phdr) * elf_ex.e_phnum;
1052 /* j < ELF_MIN_ALIGN because elf_ex.e_phnum <= 2 */
1055 elf_phdata = kmalloc(j, GFP_KERNEL);
1061 retval = kernel_read(file, elf_ex.e_phoff, (char *)eppnt, j);
1065 for (j = 0, i = 0; i<elf_ex.e_phnum; i++)
1066 if ((eppnt + i)->p_type == PT_LOAD)
1071 while (eppnt->p_type != PT_LOAD)
1074 /* Now use mmap to map the library into memory. */
1075 down_write(¤t->mm->mmap_sem);
1076 error = do_mmap(file,
1077 ELF_PAGESTART(eppnt->p_vaddr),
1079 ELF_PAGEOFFSET(eppnt->p_vaddr)),
1080 PROT_READ | PROT_WRITE | PROT_EXEC,
1081 MAP_FIXED | MAP_PRIVATE | MAP_DENYWRITE,
1083 ELF_PAGEOFFSET(eppnt->p_vaddr)));
1084 up_write(¤t->mm->mmap_sem);
1085 if (error != ELF_PAGESTART(eppnt->p_vaddr))
1088 elf_bss = eppnt->p_vaddr + eppnt->p_filesz;
1089 if (padzero(elf_bss)) {
1094 len = ELF_PAGESTART(eppnt->p_filesz + eppnt->p_vaddr +
1096 bss = eppnt->p_memsz + eppnt->p_vaddr;
1098 down_write(¤t->mm->mmap_sem);
1099 do_brk(len, bss - len);
1100 up_write(¤t->mm->mmap_sem);
1111 * Note that some platforms still use traditional core dumps and not
1112 * the ELF core dump. Each platform can select it as appropriate.
1114 #if defined(USE_ELF_CORE_DUMP) && defined(CONFIG_ELF_CORE)
1119 * Modelled on fs/exec.c:aout_core_dump()
1120 * Jeremy Fitzhardinge <jeremy@sw.oz.au>
1123 * These are the only things you should do on a core-file: use only these
1124 * functions to write out all the necessary info.
1126 static int dump_write(struct file *file, const void *addr, int nr)
1128 return file->f_op->write(file, addr, nr, &file->f_pos) == nr;
1131 static int dump_seek(struct file *file, loff_t off)
1133 if (file->f_op->llseek && file->f_op->llseek != no_llseek) {
1134 if (file->f_op->llseek(file, off, SEEK_CUR) < 0)
1137 char *buf = (char *)get_zeroed_page(GFP_KERNEL);
1141 unsigned long n = off;
1144 if (!dump_write(file, buf, n))
1148 free_page((unsigned long)buf);
1154 * Decide what to dump of a segment, part, all or none.
1156 static unsigned long vma_dump_size(struct vm_area_struct *vma,
1157 unsigned long mm_flags)
1159 /* The vma can be set up to tell us the answer directly. */
1160 if (vma->vm_flags & VM_ALWAYSDUMP)
1163 /* Do not dump I/O mapped devices or special mappings */
1164 if (vma->vm_flags & (VM_IO | VM_RESERVED))
1167 #define FILTER(type) (mm_flags & (1UL << MMF_DUMP_##type))
1169 /* By default, dump shared memory if mapped from an anonymous file. */
1170 if (vma->vm_flags & VM_SHARED) {
1171 if (vma->vm_file->f_path.dentry->d_inode->i_nlink == 0 ?
1172 FILTER(ANON_SHARED) : FILTER(MAPPED_SHARED))
1177 /* Dump segments that have been written to. */
1178 if (vma->anon_vma && FILTER(ANON_PRIVATE))
1180 if (vma->vm_file == NULL)
1183 if (FILTER(MAPPED_PRIVATE))
1187 * If this looks like the beginning of a DSO or executable mapping,
1188 * check for an ELF header. If we find one, dump the first page to
1189 * aid in determining what was mapped here.
1191 if (FILTER(ELF_HEADERS) && vma->vm_file != NULL && vma->vm_pgoff == 0) {
1192 u32 __user *header = (u32 __user *) vma->vm_start;
1195 * Doing it this way gets the constant folded by GCC.
1199 char elfmag[SELFMAG];
1201 BUILD_BUG_ON(SELFMAG != sizeof word);
1202 magic.elfmag[EI_MAG0] = ELFMAG0;
1203 magic.elfmag[EI_MAG1] = ELFMAG1;
1204 magic.elfmag[EI_MAG2] = ELFMAG2;
1205 magic.elfmag[EI_MAG3] = ELFMAG3;
1206 if (get_user(word, header) == 0 && word == magic.cmp)
1215 return vma->vm_end - vma->vm_start;
1218 /* An ELF note in memory */
1223 unsigned int datasz;
1227 static int notesize(struct memelfnote *en)
1231 sz = sizeof(struct elf_note);
1232 sz += roundup(strlen(en->name) + 1, 4);
1233 sz += roundup(en->datasz, 4);
1238 #define DUMP_WRITE(addr, nr, foffset) \
1239 do { if (!dump_write(file, (addr), (nr))) return 0; *foffset += (nr); } while(0)
1241 static int alignfile(struct file *file, loff_t *foffset)
1243 static const char buf[4] = { 0, };
1244 DUMP_WRITE(buf, roundup(*foffset, 4) - *foffset, foffset);
1248 static int writenote(struct memelfnote *men, struct file *file,
1252 en.n_namesz = strlen(men->name) + 1;
1253 en.n_descsz = men->datasz;
1254 en.n_type = men->type;
1256 DUMP_WRITE(&en, sizeof(en), foffset);
1257 DUMP_WRITE(men->name, en.n_namesz, foffset);
1258 if (!alignfile(file, foffset))
1260 DUMP_WRITE(men->data, men->datasz, foffset);
1261 if (!alignfile(file, foffset))
1268 #define DUMP_WRITE(addr, nr) \
1269 if ((size += (nr)) > limit || !dump_write(file, (addr), (nr))) \
1271 #define DUMP_SEEK(off) \
1272 if (!dump_seek(file, (off))) \
1275 static void fill_elf_header(struct elfhdr *elf, int segs,
1276 u16 machine, u32 flags, u8 osabi)
1278 memset(elf, 0, sizeof(*elf));
1280 memcpy(elf->e_ident, ELFMAG, SELFMAG);
1281 elf->e_ident[EI_CLASS] = ELF_CLASS;
1282 elf->e_ident[EI_DATA] = ELF_DATA;
1283 elf->e_ident[EI_VERSION] = EV_CURRENT;
1284 elf->e_ident[EI_OSABI] = ELF_OSABI;
1286 elf->e_type = ET_CORE;
1287 elf->e_machine = machine;
1288 elf->e_version = EV_CURRENT;
1289 elf->e_phoff = sizeof(struct elfhdr);
1290 elf->e_flags = flags;
1291 elf->e_ehsize = sizeof(struct elfhdr);
1292 elf->e_phentsize = sizeof(struct elf_phdr);
1293 elf->e_phnum = segs;
1298 static void fill_elf_note_phdr(struct elf_phdr *phdr, int sz, loff_t offset)
1300 phdr->p_type = PT_NOTE;
1301 phdr->p_offset = offset;
1304 phdr->p_filesz = sz;
1311 static void fill_note(struct memelfnote *note, const char *name, int type,
1312 unsigned int sz, void *data)
1322 * fill up all the fields in prstatus from the given task struct, except
1323 * registers which need to be filled up separately.
1325 static void fill_prstatus(struct elf_prstatus *prstatus,
1326 struct task_struct *p, long signr)
1328 prstatus->pr_info.si_signo = prstatus->pr_cursig = signr;
1329 prstatus->pr_sigpend = p->pending.signal.sig[0];
1330 prstatus->pr_sighold = p->blocked.sig[0];
1331 prstatus->pr_pid = task_pid_vnr(p);
1332 prstatus->pr_ppid = task_pid_vnr(p->real_parent);
1333 prstatus->pr_pgrp = task_pgrp_vnr(p);
1334 prstatus->pr_sid = task_session_vnr(p);
1335 if (thread_group_leader(p)) {
1336 struct task_cputime cputime;
1339 * This is the record for the group leader. It shows the
1340 * group-wide total, not its individual thread total.
1342 thread_group_cputime(p, &cputime);
1343 cputime_to_timeval(cputime.utime, &prstatus->pr_utime);
1344 cputime_to_timeval(cputime.stime, &prstatus->pr_stime);
1346 cputime_to_timeval(p->utime, &prstatus->pr_utime);
1347 cputime_to_timeval(p->stime, &prstatus->pr_stime);
1349 cputime_to_timeval(p->signal->cutime, &prstatus->pr_cutime);
1350 cputime_to_timeval(p->signal->cstime, &prstatus->pr_cstime);
1353 static int fill_psinfo(struct elf_prpsinfo *psinfo, struct task_struct *p,
1354 struct mm_struct *mm)
1356 unsigned int i, len;
1358 /* first copy the parameters from user space */
1359 memset(psinfo, 0, sizeof(struct elf_prpsinfo));
1361 len = mm->arg_end - mm->arg_start;
1362 if (len >= ELF_PRARGSZ)
1363 len = ELF_PRARGSZ-1;
1364 if (copy_from_user(&psinfo->pr_psargs,
1365 (const char __user *)mm->arg_start, len))
1367 for(i = 0; i < len; i++)
1368 if (psinfo->pr_psargs[i] == 0)
1369 psinfo->pr_psargs[i] = ' ';
1370 psinfo->pr_psargs[len] = 0;
1372 psinfo->pr_pid = task_pid_vnr(p);
1373 psinfo->pr_ppid = task_pid_vnr(p->real_parent);
1374 psinfo->pr_pgrp = task_pgrp_vnr(p);
1375 psinfo->pr_sid = task_session_vnr(p);
1377 i = p->state ? ffz(~p->state) + 1 : 0;
1378 psinfo->pr_state = i;
1379 psinfo->pr_sname = (i > 5) ? '.' : "RSDTZW"[i];
1380 psinfo->pr_zomb = psinfo->pr_sname == 'Z';
1381 psinfo->pr_nice = task_nice(p);
1382 psinfo->pr_flag = p->flags;
1383 SET_UID(psinfo->pr_uid, p->uid);
1384 SET_GID(psinfo->pr_gid, p->gid);
1385 strncpy(psinfo->pr_fname, p->comm, sizeof(psinfo->pr_fname));
1390 static void fill_auxv_note(struct memelfnote *note, struct mm_struct *mm)
1392 elf_addr_t *auxv = (elf_addr_t *) mm->saved_auxv;
1396 while (auxv[i - 2] != AT_NULL);
1397 fill_note(note, "CORE", NT_AUXV, i * sizeof(elf_addr_t), auxv);
1400 #ifdef CORE_DUMP_USE_REGSET
1401 #include <linux/regset.h>
1403 struct elf_thread_core_info {
1404 struct elf_thread_core_info *next;
1405 struct task_struct *task;
1406 struct elf_prstatus prstatus;
1407 struct memelfnote notes[0];
1410 struct elf_note_info {
1411 struct elf_thread_core_info *thread;
1412 struct memelfnote psinfo;
1413 struct memelfnote auxv;
1419 * When a regset has a writeback hook, we call it on each thread before
1420 * dumping user memory. On register window machines, this makes sure the
1421 * user memory backing the register data is up to date before we read it.
1423 static void do_thread_regset_writeback(struct task_struct *task,
1424 const struct user_regset *regset)
1426 if (regset->writeback)
1427 regset->writeback(task, regset, 1);
1430 static int fill_thread_core_info(struct elf_thread_core_info *t,
1431 const struct user_regset_view *view,
1432 long signr, size_t *total)
1437 * NT_PRSTATUS is the one special case, because the regset data
1438 * goes into the pr_reg field inside the note contents, rather
1439 * than being the whole note contents. We fill the reset in here.
1440 * We assume that regset 0 is NT_PRSTATUS.
1442 fill_prstatus(&t->prstatus, t->task, signr);
1443 (void) view->regsets[0].get(t->task, &view->regsets[0],
1444 0, sizeof(t->prstatus.pr_reg),
1445 &t->prstatus.pr_reg, NULL);
1447 fill_note(&t->notes[0], "CORE", NT_PRSTATUS,
1448 sizeof(t->prstatus), &t->prstatus);
1449 *total += notesize(&t->notes[0]);
1451 do_thread_regset_writeback(t->task, &view->regsets[0]);
1454 * Each other regset might generate a note too. For each regset
1455 * that has no core_note_type or is inactive, we leave t->notes[i]
1456 * all zero and we'll know to skip writing it later.
1458 for (i = 1; i < view->n; ++i) {
1459 const struct user_regset *regset = &view->regsets[i];
1460 do_thread_regset_writeback(t->task, regset);
1461 if (regset->core_note_type &&
1462 (!regset->active || regset->active(t->task, regset))) {
1464 size_t size = regset->n * regset->size;
1465 void *data = kmalloc(size, GFP_KERNEL);
1466 if (unlikely(!data))
1468 ret = regset->get(t->task, regset,
1469 0, size, data, NULL);
1473 if (regset->core_note_type != NT_PRFPREG)
1474 fill_note(&t->notes[i], "LINUX",
1475 regset->core_note_type,
1478 t->prstatus.pr_fpvalid = 1;
1479 fill_note(&t->notes[i], "CORE",
1480 NT_PRFPREG, size, data);
1482 *total += notesize(&t->notes[i]);
1490 static int fill_note_info(struct elfhdr *elf, int phdrs,
1491 struct elf_note_info *info,
1492 long signr, struct pt_regs *regs)
1494 struct task_struct *dump_task = current;
1495 const struct user_regset_view *view = task_user_regset_view(dump_task);
1496 struct elf_thread_core_info *t;
1497 struct elf_prpsinfo *psinfo;
1498 struct core_thread *ct;
1502 info->thread = NULL;
1504 psinfo = kmalloc(sizeof(*psinfo), GFP_KERNEL);
1505 fill_note(&info->psinfo, "CORE", NT_PRPSINFO, sizeof(*psinfo), psinfo);
1511 * Figure out how many notes we're going to need for each thread.
1513 info->thread_notes = 0;
1514 for (i = 0; i < view->n; ++i)
1515 if (view->regsets[i].core_note_type != 0)
1516 ++info->thread_notes;
1519 * Sanity check. We rely on regset 0 being in NT_PRSTATUS,
1520 * since it is our one special case.
1522 if (unlikely(info->thread_notes == 0) ||
1523 unlikely(view->regsets[0].core_note_type != NT_PRSTATUS)) {
1529 * Initialize the ELF file header.
1531 fill_elf_header(elf, phdrs,
1532 view->e_machine, view->e_flags, view->ei_osabi);
1535 * Allocate a structure for each thread.
1537 for (ct = &dump_task->mm->core_state->dumper; ct; ct = ct->next) {
1538 t = kzalloc(offsetof(struct elf_thread_core_info,
1539 notes[info->thread_notes]),
1545 if (ct->task == dump_task || !info->thread) {
1546 t->next = info->thread;
1550 * Make sure to keep the original task at
1551 * the head of the list.
1553 t->next = info->thread->next;
1554 info->thread->next = t;
1559 * Now fill in each thread's information.
1561 for (t = info->thread; t != NULL; t = t->next)
1562 if (!fill_thread_core_info(t, view, signr, &info->size))
1566 * Fill in the two process-wide notes.
1568 fill_psinfo(psinfo, dump_task->group_leader, dump_task->mm);
1569 info->size += notesize(&info->psinfo);
1571 fill_auxv_note(&info->auxv, current->mm);
1572 info->size += notesize(&info->auxv);
1577 static size_t get_note_info_size(struct elf_note_info *info)
1583 * Write all the notes for each thread. When writing the first thread, the
1584 * process-wide notes are interleaved after the first thread-specific note.
1586 static int write_note_info(struct elf_note_info *info,
1587 struct file *file, loff_t *foffset)
1590 struct elf_thread_core_info *t = info->thread;
1595 if (!writenote(&t->notes[0], file, foffset))
1598 if (first && !writenote(&info->psinfo, file, foffset))
1600 if (first && !writenote(&info->auxv, file, foffset))
1603 for (i = 1; i < info->thread_notes; ++i)
1604 if (t->notes[i].data &&
1605 !writenote(&t->notes[i], file, foffset))
1615 static void free_note_info(struct elf_note_info *info)
1617 struct elf_thread_core_info *threads = info->thread;
1620 struct elf_thread_core_info *t = threads;
1622 WARN_ON(t->notes[0].data && t->notes[0].data != &t->prstatus);
1623 for (i = 1; i < info->thread_notes; ++i)
1624 kfree(t->notes[i].data);
1627 kfree(info->psinfo.data);
1632 /* Here is the structure in which status of each thread is captured. */
1633 struct elf_thread_status
1635 struct list_head list;
1636 struct elf_prstatus prstatus; /* NT_PRSTATUS */
1637 elf_fpregset_t fpu; /* NT_PRFPREG */
1638 struct task_struct *thread;
1639 #ifdef ELF_CORE_COPY_XFPREGS
1640 elf_fpxregset_t xfpu; /* ELF_CORE_XFPREG_TYPE */
1642 struct memelfnote notes[3];
1647 * In order to add the specific thread information for the elf file format,
1648 * we need to keep a linked list of every threads pr_status and then create
1649 * a single section for them in the final core file.
1651 static int elf_dump_thread_status(long signr, struct elf_thread_status *t)
1654 struct task_struct *p = t->thread;
1657 fill_prstatus(&t->prstatus, p, signr);
1658 elf_core_copy_task_regs(p, &t->prstatus.pr_reg);
1660 fill_note(&t->notes[0], "CORE", NT_PRSTATUS, sizeof(t->prstatus),
1663 sz += notesize(&t->notes[0]);
1665 if ((t->prstatus.pr_fpvalid = elf_core_copy_task_fpregs(p, NULL,
1667 fill_note(&t->notes[1], "CORE", NT_PRFPREG, sizeof(t->fpu),
1670 sz += notesize(&t->notes[1]);
1673 #ifdef ELF_CORE_COPY_XFPREGS
1674 if (elf_core_copy_task_xfpregs(p, &t->xfpu)) {
1675 fill_note(&t->notes[2], "LINUX", ELF_CORE_XFPREG_TYPE,
1676 sizeof(t->xfpu), &t->xfpu);
1678 sz += notesize(&t->notes[2]);
1684 struct elf_note_info {
1685 struct memelfnote *notes;
1686 struct elf_prstatus *prstatus; /* NT_PRSTATUS */
1687 struct elf_prpsinfo *psinfo; /* NT_PRPSINFO */
1688 struct list_head thread_list;
1689 elf_fpregset_t *fpu;
1690 #ifdef ELF_CORE_COPY_XFPREGS
1691 elf_fpxregset_t *xfpu;
1693 int thread_status_size;
1697 static int fill_note_info(struct elfhdr *elf, int phdrs,
1698 struct elf_note_info *info,
1699 long signr, struct pt_regs *regs)
1702 struct list_head *t;
1705 info->prstatus = NULL;
1706 info->psinfo = NULL;
1708 #ifdef ELF_CORE_COPY_XFPREGS
1711 INIT_LIST_HEAD(&info->thread_list);
1713 info->notes = kmalloc(NUM_NOTES * sizeof(struct memelfnote),
1717 info->psinfo = kmalloc(sizeof(*info->psinfo), GFP_KERNEL);
1720 info->prstatus = kmalloc(sizeof(*info->prstatus), GFP_KERNEL);
1721 if (!info->prstatus)
1723 info->fpu = kmalloc(sizeof(*info->fpu), GFP_KERNEL);
1726 #ifdef ELF_CORE_COPY_XFPREGS
1727 info->xfpu = kmalloc(sizeof(*info->xfpu), GFP_KERNEL);
1732 info->thread_status_size = 0;
1734 struct core_thread *ct;
1735 struct elf_thread_status *ets;
1737 for (ct = current->mm->core_state->dumper.next;
1738 ct; ct = ct->next) {
1739 ets = kzalloc(sizeof(*ets), GFP_KERNEL);
1743 ets->thread = ct->task;
1744 list_add(&ets->list, &info->thread_list);
1747 list_for_each(t, &info->thread_list) {
1750 ets = list_entry(t, struct elf_thread_status, list);
1751 sz = elf_dump_thread_status(signr, ets);
1752 info->thread_status_size += sz;
1755 /* now collect the dump for the current */
1756 memset(info->prstatus, 0, sizeof(*info->prstatus));
1757 fill_prstatus(info->prstatus, current, signr);
1758 elf_core_copy_regs(&info->prstatus->pr_reg, regs);
1761 fill_elf_header(elf, phdrs, ELF_ARCH, ELF_CORE_EFLAGS, ELF_OSABI);
1764 * Set up the notes in similar form to SVR4 core dumps made
1765 * with info from their /proc.
1768 fill_note(info->notes + 0, "CORE", NT_PRSTATUS,
1769 sizeof(*info->prstatus), info->prstatus);
1770 fill_psinfo(info->psinfo, current->group_leader, current->mm);
1771 fill_note(info->notes + 1, "CORE", NT_PRPSINFO,
1772 sizeof(*info->psinfo), info->psinfo);
1776 fill_auxv_note(&info->notes[info->numnote++], current->mm);
1778 /* Try to dump the FPU. */
1779 info->prstatus->pr_fpvalid = elf_core_copy_task_fpregs(current, regs,
1781 if (info->prstatus->pr_fpvalid)
1782 fill_note(info->notes + info->numnote++,
1783 "CORE", NT_PRFPREG, sizeof(*info->fpu), info->fpu);
1784 #ifdef ELF_CORE_COPY_XFPREGS
1785 if (elf_core_copy_task_xfpregs(current, info->xfpu))
1786 fill_note(info->notes + info->numnote++,
1787 "LINUX", ELF_CORE_XFPREG_TYPE,
1788 sizeof(*info->xfpu), info->xfpu);
1796 static size_t get_note_info_size(struct elf_note_info *info)
1801 for (i = 0; i < info->numnote; i++)
1802 sz += notesize(info->notes + i);
1804 sz += info->thread_status_size;
1809 static int write_note_info(struct elf_note_info *info,
1810 struct file *file, loff_t *foffset)
1813 struct list_head *t;
1815 for (i = 0; i < info->numnote; i++)
1816 if (!writenote(info->notes + i, file, foffset))
1819 /* write out the thread status notes section */
1820 list_for_each(t, &info->thread_list) {
1821 struct elf_thread_status *tmp =
1822 list_entry(t, struct elf_thread_status, list);
1824 for (i = 0; i < tmp->num_notes; i++)
1825 if (!writenote(&tmp->notes[i], file, foffset))
1832 static void free_note_info(struct elf_note_info *info)
1834 while (!list_empty(&info->thread_list)) {
1835 struct list_head *tmp = info->thread_list.next;
1837 kfree(list_entry(tmp, struct elf_thread_status, list));
1840 kfree(info->prstatus);
1841 kfree(info->psinfo);
1844 #ifdef ELF_CORE_COPY_XFPREGS
1851 static struct vm_area_struct *first_vma(struct task_struct *tsk,
1852 struct vm_area_struct *gate_vma)
1854 struct vm_area_struct *ret = tsk->mm->mmap;
1861 * Helper function for iterating across a vma list. It ensures that the caller
1862 * will visit `gate_vma' prior to terminating the search.
1864 static struct vm_area_struct *next_vma(struct vm_area_struct *this_vma,
1865 struct vm_area_struct *gate_vma)
1867 struct vm_area_struct *ret;
1869 ret = this_vma->vm_next;
1872 if (this_vma == gate_vma)
1880 * This is a two-pass process; first we find the offsets of the bits,
1881 * and then they are actually written out. If we run out of core limit
1884 static int elf_core_dump(long signr, struct pt_regs *regs, struct file *file, unsigned long limit)
1890 struct vm_area_struct *vma, *gate_vma;
1891 struct elfhdr *elf = NULL;
1892 loff_t offset = 0, dataoff, foffset;
1893 unsigned long mm_flags;
1894 struct elf_note_info info;
1897 * We no longer stop all VM operations.
1899 * This is because those proceses that could possibly change map_count
1900 * or the mmap / vma pages are now blocked in do_exit on current
1901 * finishing this core dump.
1903 * Only ptrace can touch these memory addresses, but it doesn't change
1904 * the map_count or the pages allocated. So no possibility of crashing
1905 * exists while dumping the mm->vm_next areas to the core file.
1908 /* alloc memory for large data structures: too large to be on stack */
1909 elf = kmalloc(sizeof(*elf), GFP_KERNEL);
1913 segs = current->mm->map_count;
1914 #ifdef ELF_CORE_EXTRA_PHDRS
1915 segs += ELF_CORE_EXTRA_PHDRS;
1918 gate_vma = get_gate_vma(current);
1919 if (gate_vma != NULL)
1923 * Collect all the non-memory information about the process for the
1924 * notes. This also sets up the file header.
1926 if (!fill_note_info(elf, segs + 1, /* including notes section */
1927 &info, signr, regs))
1931 current->flags |= PF_DUMPCORE;
1936 DUMP_WRITE(elf, sizeof(*elf));
1937 offset += sizeof(*elf); /* Elf header */
1938 offset += (segs + 1) * sizeof(struct elf_phdr); /* Program headers */
1941 /* Write notes phdr entry */
1943 struct elf_phdr phdr;
1944 size_t sz = get_note_info_size(&info);
1946 sz += elf_coredump_extra_notes_size();
1948 fill_elf_note_phdr(&phdr, sz, offset);
1950 DUMP_WRITE(&phdr, sizeof(phdr));
1953 dataoff = offset = roundup(offset, ELF_EXEC_PAGESIZE);
1956 * We must use the same mm->flags while dumping core to avoid
1957 * inconsistency between the program headers and bodies, otherwise an
1958 * unusable core file can be generated.
1960 mm_flags = current->mm->flags;
1962 /* Write program headers for segments dump */
1963 for (vma = first_vma(current, gate_vma); vma != NULL;
1964 vma = next_vma(vma, gate_vma)) {
1965 struct elf_phdr phdr;
1967 phdr.p_type = PT_LOAD;
1968 phdr.p_offset = offset;
1969 phdr.p_vaddr = vma->vm_start;
1971 phdr.p_filesz = vma_dump_size(vma, mm_flags);
1972 phdr.p_memsz = vma->vm_end - vma->vm_start;
1973 offset += phdr.p_filesz;
1974 phdr.p_flags = vma->vm_flags & VM_READ ? PF_R : 0;
1975 if (vma->vm_flags & VM_WRITE)
1976 phdr.p_flags |= PF_W;
1977 if (vma->vm_flags & VM_EXEC)
1978 phdr.p_flags |= PF_X;
1979 phdr.p_align = ELF_EXEC_PAGESIZE;
1981 DUMP_WRITE(&phdr, sizeof(phdr));
1984 #ifdef ELF_CORE_WRITE_EXTRA_PHDRS
1985 ELF_CORE_WRITE_EXTRA_PHDRS;
1988 /* write out the notes section */
1989 if (!write_note_info(&info, file, &foffset))
1992 if (elf_coredump_extra_notes_write(file, &foffset))
1996 DUMP_SEEK(dataoff - foffset);
1998 for (vma = first_vma(current, gate_vma); vma != NULL;
1999 vma = next_vma(vma, gate_vma)) {
2003 end = vma->vm_start + vma_dump_size(vma, mm_flags);
2005 for (addr = vma->vm_start; addr < end; addr += PAGE_SIZE) {
2007 struct vm_area_struct *tmp_vma;
2009 if (get_user_pages(current, current->mm, addr, 1, 0, 1,
2010 &page, &tmp_vma) <= 0) {
2011 DUMP_SEEK(PAGE_SIZE);
2013 if (page == ZERO_PAGE(0)) {
2014 if (!dump_seek(file, PAGE_SIZE)) {
2015 page_cache_release(page);
2020 flush_cache_page(tmp_vma, addr,
2023 if ((size += PAGE_SIZE) > limit ||
2024 !dump_write(file, kaddr,
2027 page_cache_release(page);
2032 page_cache_release(page);
2037 #ifdef ELF_CORE_WRITE_EXTRA_DATA
2038 ELF_CORE_WRITE_EXTRA_DATA;
2045 free_note_info(&info);
2051 #endif /* USE_ELF_CORE_DUMP */
2053 static int __init init_elf_binfmt(void)
2055 return register_binfmt(&elf_format);
2058 static void __exit exit_elf_binfmt(void)
2060 /* Remove the COFF and ELF loaders. */
2061 unregister_binfmt(&elf_format);
2064 core_initcall(init_elf_binfmt);
2065 module_exit(exit_elf_binfmt);
2066 MODULE_LICENSE("GPL");