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>
40 static int load_elf_binary(struct linux_binprm *bprm, struct pt_regs *regs);
41 static int load_elf_library(struct file *);
42 static unsigned long elf_map(struct file *, unsigned long, struct elf_phdr *,
43 int, int, unsigned long);
46 * If we don't support core dumping, then supply a NULL so we
49 #ifdef CONFIG_ELF_CORE
50 static int elf_core_dump(struct coredump_params *cprm);
52 #define elf_core_dump NULL
55 #if ELF_EXEC_PAGESIZE > PAGE_SIZE
56 #define ELF_MIN_ALIGN ELF_EXEC_PAGESIZE
58 #define ELF_MIN_ALIGN PAGE_SIZE
61 #ifndef ELF_CORE_EFLAGS
62 #define ELF_CORE_EFLAGS 0
65 #define ELF_PAGESTART(_v) ((_v) & ~(unsigned long)(ELF_MIN_ALIGN-1))
66 #define ELF_PAGEOFFSET(_v) ((_v) & (ELF_MIN_ALIGN-1))
67 #define ELF_PAGEALIGN(_v) (((_v) + ELF_MIN_ALIGN - 1) & ~(ELF_MIN_ALIGN - 1))
69 static struct linux_binfmt elf_format = {
70 .module = THIS_MODULE,
71 .load_binary = load_elf_binary,
72 .load_shlib = load_elf_library,
73 .core_dump = elf_core_dump,
74 .min_coredump = ELF_EXEC_PAGESIZE,
77 #define BAD_ADDR(x) ((unsigned long)(x) >= TASK_SIZE)
79 static int set_brk(unsigned long start, unsigned long end)
81 start = ELF_PAGEALIGN(start);
82 end = ELF_PAGEALIGN(end);
85 down_write(¤t->mm->mmap_sem);
86 addr = do_brk(start, end - start);
87 up_write(¤t->mm->mmap_sem);
91 current->mm->start_brk = current->mm->brk = end;
95 /* We need to explicitly zero any fractional pages
96 after the data section (i.e. bss). This would
97 contain the junk from the file that should not
100 static int padzero(unsigned long elf_bss)
104 nbyte = ELF_PAGEOFFSET(elf_bss);
106 nbyte = ELF_MIN_ALIGN - nbyte;
107 if (clear_user((void __user *) elf_bss, nbyte))
113 /* Let's use some macros to make this stack manipulation a little clearer */
114 #ifdef CONFIG_STACK_GROWSUP
115 #define STACK_ADD(sp, items) ((elf_addr_t __user *)(sp) + (items))
116 #define STACK_ROUND(sp, items) \
117 ((15 + (unsigned long) ((sp) + (items))) &~ 15UL)
118 #define STACK_ALLOC(sp, len) ({ \
119 elf_addr_t __user *old_sp = (elf_addr_t __user *)sp; sp += len; \
122 #define STACK_ADD(sp, items) ((elf_addr_t __user *)(sp) - (items))
123 #define STACK_ROUND(sp, items) \
124 (((unsigned long) (sp - items)) &~ 15UL)
125 #define STACK_ALLOC(sp, len) ({ sp -= len ; sp; })
128 #ifndef ELF_BASE_PLATFORM
130 * AT_BASE_PLATFORM indicates the "real" hardware/microarchitecture.
131 * If the arch defines ELF_BASE_PLATFORM (in asm/elf.h), the value
132 * will be copied to the user stack in the same manner as AT_PLATFORM.
134 #define ELF_BASE_PLATFORM NULL
138 create_elf_tables(struct linux_binprm *bprm, struct elfhdr *exec,
139 unsigned long load_addr, unsigned long interp_load_addr)
141 unsigned long p = bprm->p;
142 int argc = bprm->argc;
143 int envc = bprm->envc;
144 elf_addr_t __user *argv;
145 elf_addr_t __user *envp;
146 elf_addr_t __user *sp;
147 elf_addr_t __user *u_platform;
148 elf_addr_t __user *u_base_platform;
149 elf_addr_t __user *u_rand_bytes;
150 const char *k_platform = ELF_PLATFORM;
151 const char *k_base_platform = ELF_BASE_PLATFORM;
152 unsigned char k_rand_bytes[16];
154 elf_addr_t *elf_info;
156 const struct cred *cred = current_cred();
157 struct vm_area_struct *vma;
160 * In some cases (e.g. Hyper-Threading), we want to avoid L1
161 * evictions by the processes running on the same package. One
162 * thing we can do is to shuffle the initial stack for them.
165 p = arch_align_stack(p);
168 * If this architecture has a platform capability string, copy it
169 * to userspace. In some cases (Sparc), this info is impossible
170 * for userspace to get any other way, in others (i386) it is
175 size_t len = strlen(k_platform) + 1;
177 u_platform = (elf_addr_t __user *)STACK_ALLOC(p, len);
178 if (__copy_to_user(u_platform, k_platform, len))
183 * If this architecture has a "base" platform capability
184 * string, copy it to userspace.
186 u_base_platform = NULL;
187 if (k_base_platform) {
188 size_t len = strlen(k_base_platform) + 1;
190 u_base_platform = (elf_addr_t __user *)STACK_ALLOC(p, len);
191 if (__copy_to_user(u_base_platform, k_base_platform, len))
196 * Generate 16 random bytes for userspace PRNG seeding.
198 get_random_bytes(k_rand_bytes, sizeof(k_rand_bytes));
199 u_rand_bytes = (elf_addr_t __user *)
200 STACK_ALLOC(p, sizeof(k_rand_bytes));
201 if (__copy_to_user(u_rand_bytes, k_rand_bytes, sizeof(k_rand_bytes)))
204 /* Create the ELF interpreter info */
205 elf_info = (elf_addr_t *)current->mm->saved_auxv;
206 /* update AT_VECTOR_SIZE_BASE if the number of NEW_AUX_ENT() changes */
207 #define NEW_AUX_ENT(id, val) \
209 elf_info[ei_index++] = id; \
210 elf_info[ei_index++] = val; \
215 * ARCH_DLINFO must come first so PPC can do its special alignment of
217 * update AT_VECTOR_SIZE_ARCH if the number of NEW_AUX_ENT() in
218 * ARCH_DLINFO changes
222 NEW_AUX_ENT(AT_HWCAP, ELF_HWCAP);
223 NEW_AUX_ENT(AT_PAGESZ, ELF_EXEC_PAGESIZE);
224 NEW_AUX_ENT(AT_CLKTCK, CLOCKS_PER_SEC);
225 NEW_AUX_ENT(AT_PHDR, load_addr + exec->e_phoff);
226 NEW_AUX_ENT(AT_PHENT, sizeof(struct elf_phdr));
227 NEW_AUX_ENT(AT_PHNUM, exec->e_phnum);
228 NEW_AUX_ENT(AT_BASE, interp_load_addr);
229 NEW_AUX_ENT(AT_FLAGS, 0);
230 NEW_AUX_ENT(AT_ENTRY, exec->e_entry);
231 NEW_AUX_ENT(AT_UID, cred->uid);
232 NEW_AUX_ENT(AT_EUID, cred->euid);
233 NEW_AUX_ENT(AT_GID, cred->gid);
234 NEW_AUX_ENT(AT_EGID, cred->egid);
235 NEW_AUX_ENT(AT_SECURE, security_bprm_secureexec(bprm));
236 NEW_AUX_ENT(AT_RANDOM, (elf_addr_t)(unsigned long)u_rand_bytes);
237 NEW_AUX_ENT(AT_EXECFN, bprm->exec);
239 NEW_AUX_ENT(AT_PLATFORM,
240 (elf_addr_t)(unsigned long)u_platform);
242 if (k_base_platform) {
243 NEW_AUX_ENT(AT_BASE_PLATFORM,
244 (elf_addr_t)(unsigned long)u_base_platform);
246 if (bprm->interp_flags & BINPRM_FLAGS_EXECFD) {
247 NEW_AUX_ENT(AT_EXECFD, bprm->interp_data);
250 /* AT_NULL is zero; clear the rest too */
251 memset(&elf_info[ei_index], 0,
252 sizeof current->mm->saved_auxv - ei_index * sizeof elf_info[0]);
254 /* And advance past the AT_NULL entry. */
257 sp = STACK_ADD(p, ei_index);
259 items = (argc + 1) + (envc + 1) + 1;
260 bprm->p = STACK_ROUND(sp, items);
262 /* Point sp at the lowest address on the stack */
263 #ifdef CONFIG_STACK_GROWSUP
264 sp = (elf_addr_t __user *)bprm->p - items - ei_index;
265 bprm->exec = (unsigned long)sp; /* XXX: PARISC HACK */
267 sp = (elf_addr_t __user *)bprm->p;
272 * Grow the stack manually; some architectures have a limit on how
273 * far ahead a user-space access may be in order to grow the stack.
275 vma = find_extend_vma(current->mm, bprm->p);
279 /* Now, let's put argc (and argv, envp if appropriate) on the stack */
280 if (__put_user(argc, sp++))
283 envp = argv + argc + 1;
285 /* Populate argv and envp */
286 p = current->mm->arg_end = current->mm->arg_start;
289 if (__put_user((elf_addr_t)p, argv++))
291 len = strnlen_user((void __user *)p, MAX_ARG_STRLEN);
292 if (!len || len > MAX_ARG_STRLEN)
296 if (__put_user(0, argv))
298 current->mm->arg_end = current->mm->env_start = p;
301 if (__put_user((elf_addr_t)p, envp++))
303 len = strnlen_user((void __user *)p, MAX_ARG_STRLEN);
304 if (!len || len > MAX_ARG_STRLEN)
308 if (__put_user(0, envp))
310 current->mm->env_end = p;
312 /* Put the elf_info on the stack in the right place. */
313 sp = (elf_addr_t __user *)envp + 1;
314 if (copy_to_user(sp, elf_info, ei_index * sizeof(elf_addr_t)))
319 static unsigned long elf_map(struct file *filep, unsigned long addr,
320 struct elf_phdr *eppnt, int prot, int type,
321 unsigned long total_size)
323 unsigned long map_addr;
324 unsigned long size = eppnt->p_filesz + ELF_PAGEOFFSET(eppnt->p_vaddr);
325 unsigned long off = eppnt->p_offset - ELF_PAGEOFFSET(eppnt->p_vaddr);
326 addr = ELF_PAGESTART(addr);
327 size = ELF_PAGEALIGN(size);
329 /* mmap() will return -EINVAL if given a zero size, but a
330 * segment with zero filesize is perfectly valid */
334 down_write(¤t->mm->mmap_sem);
336 * total_size is the size of the ELF (interpreter) image.
337 * The _first_ mmap needs to know the full size, otherwise
338 * randomization might put this image into an overlapping
339 * position with the ELF binary image. (since size < total_size)
340 * So we first map the 'big' image - and unmap the remainder at
341 * the end. (which unmap is needed for ELF images with holes.)
344 total_size = ELF_PAGEALIGN(total_size);
345 map_addr = do_mmap(filep, addr, total_size, prot, type, off);
346 if (!BAD_ADDR(map_addr))
347 do_munmap(current->mm, map_addr+size, total_size-size);
349 map_addr = do_mmap(filep, addr, size, prot, type, off);
351 up_write(¤t->mm->mmap_sem);
355 static unsigned long total_mapping_size(struct elf_phdr *cmds, int nr)
357 int i, first_idx = -1, last_idx = -1;
359 for (i = 0; i < nr; i++) {
360 if (cmds[i].p_type == PT_LOAD) {
369 return cmds[last_idx].p_vaddr + cmds[last_idx].p_memsz -
370 ELF_PAGESTART(cmds[first_idx].p_vaddr);
374 /* This is much more generalized than the library routine read function,
375 so we keep this separate. Technically the library read function
376 is only provided so that we can read a.out libraries that have
379 static unsigned long load_elf_interp(struct elfhdr *interp_elf_ex,
380 struct file *interpreter, unsigned long *interp_map_addr,
381 unsigned long no_base)
383 struct elf_phdr *elf_phdata;
384 struct elf_phdr *eppnt;
385 unsigned long load_addr = 0;
386 int load_addr_set = 0;
387 unsigned long last_bss = 0, elf_bss = 0;
388 unsigned long error = ~0UL;
389 unsigned long total_size;
392 /* First of all, some simple consistency checks */
393 if (interp_elf_ex->e_type != ET_EXEC &&
394 interp_elf_ex->e_type != ET_DYN)
396 if (!elf_check_arch(interp_elf_ex))
398 if (!interpreter->f_op || !interpreter->f_op->mmap)
402 * If the size of this structure has changed, then punt, since
403 * we will be doing the wrong thing.
405 if (interp_elf_ex->e_phentsize != sizeof(struct elf_phdr))
407 if (interp_elf_ex->e_phnum < 1 ||
408 interp_elf_ex->e_phnum > 65536U / sizeof(struct elf_phdr))
411 /* Now read in all of the header information */
412 size = sizeof(struct elf_phdr) * interp_elf_ex->e_phnum;
413 if (size > ELF_MIN_ALIGN)
415 elf_phdata = kmalloc(size, GFP_KERNEL);
419 retval = kernel_read(interpreter, interp_elf_ex->e_phoff,
420 (char *)elf_phdata, size);
422 if (retval != size) {
428 total_size = total_mapping_size(elf_phdata, interp_elf_ex->e_phnum);
435 for (i = 0; i < interp_elf_ex->e_phnum; i++, eppnt++) {
436 if (eppnt->p_type == PT_LOAD) {
437 int elf_type = MAP_PRIVATE | MAP_DENYWRITE;
439 unsigned long vaddr = 0;
440 unsigned long k, map_addr;
442 if (eppnt->p_flags & PF_R)
443 elf_prot = PROT_READ;
444 if (eppnt->p_flags & PF_W)
445 elf_prot |= PROT_WRITE;
446 if (eppnt->p_flags & PF_X)
447 elf_prot |= PROT_EXEC;
448 vaddr = eppnt->p_vaddr;
449 if (interp_elf_ex->e_type == ET_EXEC || load_addr_set)
450 elf_type |= MAP_FIXED;
451 else if (no_base && interp_elf_ex->e_type == ET_DYN)
454 map_addr = elf_map(interpreter, load_addr + vaddr,
455 eppnt, elf_prot, elf_type, total_size);
457 if (!*interp_map_addr)
458 *interp_map_addr = map_addr;
460 if (BAD_ADDR(map_addr))
463 if (!load_addr_set &&
464 interp_elf_ex->e_type == ET_DYN) {
465 load_addr = map_addr - ELF_PAGESTART(vaddr);
470 * Check to see if the section's size will overflow the
471 * allowed task size. Note that p_filesz must always be
472 * <= p_memsize so it's only necessary to check p_memsz.
474 k = load_addr + eppnt->p_vaddr;
476 eppnt->p_filesz > eppnt->p_memsz ||
477 eppnt->p_memsz > TASK_SIZE ||
478 TASK_SIZE - eppnt->p_memsz < k) {
484 * Find the end of the file mapping for this phdr, and
485 * keep track of the largest address we see for this.
487 k = load_addr + eppnt->p_vaddr + eppnt->p_filesz;
492 * Do the same thing for the memory mapping - between
493 * elf_bss and last_bss is the bss section.
495 k = load_addr + eppnt->p_memsz + eppnt->p_vaddr;
501 if (last_bss > elf_bss) {
503 * Now fill out the bss section. First pad the last page up
504 * to the page boundary, and then perform a mmap to make sure
505 * that there are zero-mapped pages up to and including the
508 if (padzero(elf_bss)) {
513 /* What we have mapped so far */
514 elf_bss = ELF_PAGESTART(elf_bss + ELF_MIN_ALIGN - 1);
516 /* Map the last of the bss segment */
517 down_write(¤t->mm->mmap_sem);
518 error = do_brk(elf_bss, last_bss - elf_bss);
519 up_write(¤t->mm->mmap_sem);
533 * These are the functions used to load ELF style executables and shared
534 * libraries. There is no binary dependent code anywhere else.
537 #define INTERPRETER_NONE 0
538 #define INTERPRETER_ELF 2
540 #ifndef STACK_RND_MASK
541 #define STACK_RND_MASK (0x7ff >> (PAGE_SHIFT - 12)) /* 8MB of VA */
544 static unsigned long randomize_stack_top(unsigned long stack_top)
546 unsigned int random_variable = 0;
548 if ((current->flags & PF_RANDOMIZE) &&
549 !(current->personality & ADDR_NO_RANDOMIZE)) {
550 random_variable = get_random_int() & STACK_RND_MASK;
551 random_variable <<= PAGE_SHIFT;
553 #ifdef CONFIG_STACK_GROWSUP
554 return PAGE_ALIGN(stack_top) + random_variable;
556 return PAGE_ALIGN(stack_top) - random_variable;
560 static int load_elf_binary(struct linux_binprm *bprm, struct pt_regs *regs)
562 struct file *interpreter = NULL; /* to shut gcc up */
563 unsigned long load_addr = 0, load_bias = 0;
564 int load_addr_set = 0;
565 char * elf_interpreter = NULL;
567 struct elf_phdr *elf_ppnt, *elf_phdata;
568 unsigned long elf_bss, elf_brk;
571 unsigned long elf_entry;
572 unsigned long interp_load_addr = 0;
573 unsigned long start_code, end_code, start_data, end_data;
574 unsigned long reloc_func_desc __maybe_unused = 0;
575 int executable_stack = EXSTACK_DEFAULT;
576 unsigned long def_flags = 0;
578 struct elfhdr elf_ex;
579 struct elfhdr interp_elf_ex;
582 loc = kmalloc(sizeof(*loc), GFP_KERNEL);
588 /* Get the exec-header */
589 loc->elf_ex = *((struct elfhdr *)bprm->buf);
592 /* First of all, some simple consistency checks */
593 if (memcmp(loc->elf_ex.e_ident, ELFMAG, SELFMAG) != 0)
596 if (loc->elf_ex.e_type != ET_EXEC && loc->elf_ex.e_type != ET_DYN)
598 if (!elf_check_arch(&loc->elf_ex))
600 if (!bprm->file->f_op || !bprm->file->f_op->mmap)
603 /* Now read in all of the header information */
604 if (loc->elf_ex.e_phentsize != sizeof(struct elf_phdr))
606 if (loc->elf_ex.e_phnum < 1 ||
607 loc->elf_ex.e_phnum > 65536U / sizeof(struct elf_phdr))
609 size = loc->elf_ex.e_phnum * sizeof(struct elf_phdr);
611 elf_phdata = kmalloc(size, GFP_KERNEL);
615 retval = kernel_read(bprm->file, loc->elf_ex.e_phoff,
616 (char *)elf_phdata, size);
617 if (retval != size) {
623 elf_ppnt = elf_phdata;
632 for (i = 0; i < loc->elf_ex.e_phnum; i++) {
633 if (elf_ppnt->p_type == PT_INTERP) {
634 /* This is the program interpreter used for
635 * shared libraries - for now assume that this
636 * is an a.out format binary
639 if (elf_ppnt->p_filesz > PATH_MAX ||
640 elf_ppnt->p_filesz < 2)
644 elf_interpreter = kmalloc(elf_ppnt->p_filesz,
646 if (!elf_interpreter)
649 retval = kernel_read(bprm->file, elf_ppnt->p_offset,
652 if (retval != elf_ppnt->p_filesz) {
655 goto out_free_interp;
657 /* make sure path is NULL terminated */
659 if (elf_interpreter[elf_ppnt->p_filesz - 1] != '\0')
660 goto out_free_interp;
662 interpreter = open_exec(elf_interpreter);
663 retval = PTR_ERR(interpreter);
664 if (IS_ERR(interpreter))
665 goto out_free_interp;
668 * If the binary is not readable then enforce
669 * mm->dumpable = 0 regardless of the interpreter's
672 would_dump(bprm, interpreter);
674 retval = kernel_read(interpreter, 0, bprm->buf,
676 if (retval != BINPRM_BUF_SIZE) {
679 goto out_free_dentry;
682 /* Get the exec headers */
683 loc->interp_elf_ex = *((struct elfhdr *)bprm->buf);
689 elf_ppnt = elf_phdata;
690 for (i = 0; i < loc->elf_ex.e_phnum; i++, elf_ppnt++)
691 if (elf_ppnt->p_type == PT_GNU_STACK) {
692 if (elf_ppnt->p_flags & PF_X)
693 executable_stack = EXSTACK_ENABLE_X;
695 executable_stack = EXSTACK_DISABLE_X;
699 /* Some simple consistency checks for the interpreter */
700 if (elf_interpreter) {
702 /* Not an ELF interpreter */
703 if (memcmp(loc->interp_elf_ex.e_ident, ELFMAG, SELFMAG) != 0)
704 goto out_free_dentry;
705 /* Verify the interpreter has a valid arch */
706 if (!elf_check_arch(&loc->interp_elf_ex))
707 goto out_free_dentry;
710 /* Flush all traces of the currently running executable */
711 retval = flush_old_exec(bprm);
713 goto out_free_dentry;
715 /* OK, This is the point of no return */
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 #ifdef CONFIG_ARCH_BINFMT_ELF_RANDOMIZE_PIE
798 /* Memory randomization might have been switched off
799 * in runtime via sysctl.
800 * If that is the case, retain the original non-zero
801 * load_bias value in order to establish proper
802 * non-randomized mappings.
804 if (current->flags & PF_RANDOMIZE)
807 load_bias = ELF_PAGESTART(ELF_ET_DYN_BASE - vaddr);
809 load_bias = ELF_PAGESTART(ELF_ET_DYN_BASE - vaddr);
813 error = elf_map(bprm->file, load_bias + vaddr, elf_ppnt,
814 elf_prot, elf_flags, 0);
815 if (BAD_ADDR(error)) {
816 send_sig(SIGKILL, current, 0);
817 retval = IS_ERR((void *)error) ?
818 PTR_ERR((void*)error) : -EINVAL;
819 goto out_free_dentry;
822 if (!load_addr_set) {
824 load_addr = (elf_ppnt->p_vaddr - elf_ppnt->p_offset);
825 if (loc->elf_ex.e_type == ET_DYN) {
827 ELF_PAGESTART(load_bias + vaddr);
828 load_addr += load_bias;
829 reloc_func_desc = load_bias;
832 k = elf_ppnt->p_vaddr;
839 * Check to see if the section's size will overflow the
840 * allowed task size. Note that p_filesz must always be
841 * <= p_memsz so it is only necessary to check p_memsz.
843 if (BAD_ADDR(k) || elf_ppnt->p_filesz > elf_ppnt->p_memsz ||
844 elf_ppnt->p_memsz > TASK_SIZE ||
845 TASK_SIZE - elf_ppnt->p_memsz < k) {
846 /* set_brk can never work. Avoid overflows. */
847 send_sig(SIGKILL, current, 0);
849 goto out_free_dentry;
852 k = elf_ppnt->p_vaddr + elf_ppnt->p_filesz;
856 if ((elf_ppnt->p_flags & PF_X) && end_code < k)
860 k = elf_ppnt->p_vaddr + elf_ppnt->p_memsz;
865 loc->elf_ex.e_entry += load_bias;
866 elf_bss += load_bias;
867 elf_brk += load_bias;
868 start_code += load_bias;
869 end_code += load_bias;
870 start_data += load_bias;
871 end_data += load_bias;
873 /* Calling set_brk effectively mmaps the pages that we need
874 * for the bss and break sections. We must do this before
875 * mapping in the interpreter, to make sure it doesn't wind
876 * up getting placed where the bss needs to go.
878 retval = set_brk(elf_bss, elf_brk);
880 send_sig(SIGKILL, current, 0);
881 goto out_free_dentry;
883 if (likely(elf_bss != elf_brk) && unlikely(padzero(elf_bss))) {
884 send_sig(SIGSEGV, current, 0);
885 retval = -EFAULT; /* Nobody gets to see this, but.. */
886 goto out_free_dentry;
889 if (elf_interpreter) {
890 unsigned long uninitialized_var(interp_map_addr);
892 elf_entry = load_elf_interp(&loc->interp_elf_ex,
896 if (!IS_ERR((void *)elf_entry)) {
898 * load_elf_interp() returns relocation
901 interp_load_addr = elf_entry;
902 elf_entry += loc->interp_elf_ex.e_entry;
904 if (BAD_ADDR(elf_entry)) {
905 force_sig(SIGSEGV, current);
906 retval = IS_ERR((void *)elf_entry) ?
907 (int)elf_entry : -EINVAL;
908 goto out_free_dentry;
910 reloc_func_desc = interp_load_addr;
912 allow_write_access(interpreter);
914 kfree(elf_interpreter);
916 elf_entry = loc->elf_ex.e_entry;
917 if (BAD_ADDR(elf_entry)) {
918 force_sig(SIGSEGV, current);
920 goto out_free_dentry;
926 set_binfmt(&elf_format);
928 #ifdef ARCH_HAS_SETUP_ADDITIONAL_PAGES
929 retval = arch_setup_additional_pages(bprm, !!elf_interpreter);
931 send_sig(SIGKILL, current, 0);
934 #endif /* ARCH_HAS_SETUP_ADDITIONAL_PAGES */
936 install_exec_creds(bprm);
937 retval = create_elf_tables(bprm, &loc->elf_ex,
938 load_addr, interp_load_addr);
940 send_sig(SIGKILL, current, 0);
943 /* N.B. passed_fileno might not be initialized? */
944 current->mm->end_code = end_code;
945 current->mm->start_code = start_code;
946 current->mm->start_data = start_data;
947 current->mm->end_data = end_data;
948 current->mm->start_stack = bprm->p;
950 #ifdef arch_randomize_brk
951 if ((current->flags & PF_RANDOMIZE) && (randomize_va_space > 1)) {
952 current->mm->brk = current->mm->start_brk =
953 arch_randomize_brk(current->mm);
954 #ifdef CONFIG_COMPAT_BRK
955 current->brk_randomized = 1;
960 if (current->personality & MMAP_PAGE_ZERO) {
961 /* Why this, you ask??? Well SVr4 maps page 0 as read-only,
962 and some applications "depend" upon this behavior.
963 Since we do not have the power to recompile these, we
964 emulate the SVr4 behavior. Sigh. */
965 down_write(¤t->mm->mmap_sem);
966 error = do_mmap(NULL, 0, PAGE_SIZE, PROT_READ | PROT_EXEC,
967 MAP_FIXED | MAP_PRIVATE, 0);
968 up_write(¤t->mm->mmap_sem);
973 * The ABI may specify that certain registers be set up in special
974 * ways (on i386 %edx is the address of a DT_FINI function, for
975 * example. In addition, it may also specify (eg, PowerPC64 ELF)
976 * that the e_entry field is the address of the function descriptor
977 * for the startup routine, rather than the address of the startup
978 * routine itself. This macro performs whatever initialization to
979 * the regs structure is required as well as any relocations to the
980 * function descriptor entries when executing dynamically links apps.
982 ELF_PLAT_INIT(regs, reloc_func_desc);
985 start_thread(regs, elf_entry, bprm->p);
994 allow_write_access(interpreter);
998 kfree(elf_interpreter);
1004 /* This is really simpleminded and specialized - we are loading an
1005 a.out library that is given an ELF header. */
1006 static int load_elf_library(struct file *file)
1008 struct elf_phdr *elf_phdata;
1009 struct elf_phdr *eppnt;
1010 unsigned long elf_bss, bss, len;
1011 int retval, error, i, j;
1012 struct elfhdr elf_ex;
1015 retval = kernel_read(file, 0, (char *)&elf_ex, sizeof(elf_ex));
1016 if (retval != sizeof(elf_ex))
1019 if (memcmp(elf_ex.e_ident, ELFMAG, SELFMAG) != 0)
1022 /* First of all, some simple consistency checks */
1023 if (elf_ex.e_type != ET_EXEC || elf_ex.e_phnum > 2 ||
1024 !elf_check_arch(&elf_ex) || !file->f_op || !file->f_op->mmap)
1027 /* Now read in all of the header information */
1029 j = sizeof(struct elf_phdr) * elf_ex.e_phnum;
1030 /* j < ELF_MIN_ALIGN because elf_ex.e_phnum <= 2 */
1033 elf_phdata = kmalloc(j, GFP_KERNEL);
1039 retval = kernel_read(file, elf_ex.e_phoff, (char *)eppnt, j);
1043 for (j = 0, i = 0; i<elf_ex.e_phnum; i++)
1044 if ((eppnt + i)->p_type == PT_LOAD)
1049 while (eppnt->p_type != PT_LOAD)
1052 /* Now use mmap to map the library into memory. */
1053 down_write(¤t->mm->mmap_sem);
1054 error = do_mmap(file,
1055 ELF_PAGESTART(eppnt->p_vaddr),
1057 ELF_PAGEOFFSET(eppnt->p_vaddr)),
1058 PROT_READ | PROT_WRITE | PROT_EXEC,
1059 MAP_FIXED | MAP_PRIVATE | MAP_DENYWRITE,
1061 ELF_PAGEOFFSET(eppnt->p_vaddr)));
1062 up_write(¤t->mm->mmap_sem);
1063 if (error != ELF_PAGESTART(eppnt->p_vaddr))
1066 elf_bss = eppnt->p_vaddr + eppnt->p_filesz;
1067 if (padzero(elf_bss)) {
1072 len = ELF_PAGESTART(eppnt->p_filesz + eppnt->p_vaddr +
1074 bss = eppnt->p_memsz + eppnt->p_vaddr;
1076 down_write(¤t->mm->mmap_sem);
1077 do_brk(len, bss - len);
1078 up_write(¤t->mm->mmap_sem);
1088 #ifdef CONFIG_ELF_CORE
1092 * Modelled on fs/exec.c:aout_core_dump()
1093 * Jeremy Fitzhardinge <jeremy@sw.oz.au>
1097 * The purpose of always_dump_vma() is to make sure that special kernel mappings
1098 * that are useful for post-mortem analysis are included in every core dump.
1099 * In that way we ensure that the core dump is fully interpretable later
1100 * without matching up the same kernel and hardware config to see what PC values
1101 * meant. These special mappings include - vDSO, vsyscall, and other
1102 * architecture specific mappings
1104 static bool always_dump_vma(struct vm_area_struct *vma)
1106 /* Any vsyscall mappings? */
1107 if (vma == get_gate_vma(vma->vm_mm))
1110 * arch_vma_name() returns non-NULL for special architecture mappings,
1111 * such as vDSO sections.
1113 if (arch_vma_name(vma))
1120 * Decide what to dump of a segment, part, all or none.
1122 static unsigned long vma_dump_size(struct vm_area_struct *vma,
1123 unsigned long mm_flags)
1125 #define FILTER(type) (mm_flags & (1UL << MMF_DUMP_##type))
1127 /* always dump the vdso and vsyscall sections */
1128 if (always_dump_vma(vma))
1131 if (vma->vm_flags & VM_NODUMP)
1134 /* Hugetlb memory check */
1135 if (vma->vm_flags & VM_HUGETLB) {
1136 if ((vma->vm_flags & VM_SHARED) && FILTER(HUGETLB_SHARED))
1138 if (!(vma->vm_flags & VM_SHARED) && FILTER(HUGETLB_PRIVATE))
1142 /* Do not dump I/O mapped devices or special mappings */
1143 if (vma->vm_flags & (VM_IO | VM_RESERVED))
1146 /* By default, dump shared memory if mapped from an anonymous file. */
1147 if (vma->vm_flags & VM_SHARED) {
1148 if (vma->vm_file->f_path.dentry->d_inode->i_nlink == 0 ?
1149 FILTER(ANON_SHARED) : FILTER(MAPPED_SHARED))
1154 /* Dump segments that have been written to. */
1155 if (vma->anon_vma && FILTER(ANON_PRIVATE))
1157 if (vma->vm_file == NULL)
1160 if (FILTER(MAPPED_PRIVATE))
1164 * If this looks like the beginning of a DSO or executable mapping,
1165 * check for an ELF header. If we find one, dump the first page to
1166 * aid in determining what was mapped here.
1168 if (FILTER(ELF_HEADERS) &&
1169 vma->vm_pgoff == 0 && (vma->vm_flags & VM_READ)) {
1170 u32 __user *header = (u32 __user *) vma->vm_start;
1172 mm_segment_t fs = get_fs();
1174 * Doing it this way gets the constant folded by GCC.
1178 char elfmag[SELFMAG];
1180 BUILD_BUG_ON(SELFMAG != sizeof word);
1181 magic.elfmag[EI_MAG0] = ELFMAG0;
1182 magic.elfmag[EI_MAG1] = ELFMAG1;
1183 magic.elfmag[EI_MAG2] = ELFMAG2;
1184 magic.elfmag[EI_MAG3] = ELFMAG3;
1186 * Switch to the user "segment" for get_user(),
1187 * then put back what elf_core_dump() had in place.
1190 if (unlikely(get_user(word, header)))
1193 if (word == magic.cmp)
1202 return vma->vm_end - vma->vm_start;
1205 /* An ELF note in memory */
1210 unsigned int datasz;
1214 static int notesize(struct memelfnote *en)
1218 sz = sizeof(struct elf_note);
1219 sz += roundup(strlen(en->name) + 1, 4);
1220 sz += roundup(en->datasz, 4);
1225 #define DUMP_WRITE(addr, nr, foffset) \
1226 do { if (!dump_write(file, (addr), (nr))) return 0; *foffset += (nr); } while(0)
1228 static int alignfile(struct file *file, loff_t *foffset)
1230 static const char buf[4] = { 0, };
1231 DUMP_WRITE(buf, roundup(*foffset, 4) - *foffset, foffset);
1235 static int writenote(struct memelfnote *men, struct file *file,
1239 en.n_namesz = strlen(men->name) + 1;
1240 en.n_descsz = men->datasz;
1241 en.n_type = men->type;
1243 DUMP_WRITE(&en, sizeof(en), foffset);
1244 DUMP_WRITE(men->name, en.n_namesz, foffset);
1245 if (!alignfile(file, foffset))
1247 DUMP_WRITE(men->data, men->datasz, foffset);
1248 if (!alignfile(file, foffset))
1255 static void fill_elf_header(struct elfhdr *elf, int segs,
1256 u16 machine, u32 flags, u8 osabi)
1258 memset(elf, 0, sizeof(*elf));
1260 memcpy(elf->e_ident, ELFMAG, SELFMAG);
1261 elf->e_ident[EI_CLASS] = ELF_CLASS;
1262 elf->e_ident[EI_DATA] = ELF_DATA;
1263 elf->e_ident[EI_VERSION] = EV_CURRENT;
1264 elf->e_ident[EI_OSABI] = ELF_OSABI;
1266 elf->e_type = ET_CORE;
1267 elf->e_machine = machine;
1268 elf->e_version = EV_CURRENT;
1269 elf->e_phoff = sizeof(struct elfhdr);
1270 elf->e_flags = flags;
1271 elf->e_ehsize = sizeof(struct elfhdr);
1272 elf->e_phentsize = sizeof(struct elf_phdr);
1273 elf->e_phnum = segs;
1278 static void fill_elf_note_phdr(struct elf_phdr *phdr, int sz, loff_t offset)
1280 phdr->p_type = PT_NOTE;
1281 phdr->p_offset = offset;
1284 phdr->p_filesz = sz;
1291 static void fill_note(struct memelfnote *note, const char *name, int type,
1292 unsigned int sz, void *data)
1302 * fill up all the fields in prstatus from the given task struct, except
1303 * registers which need to be filled up separately.
1305 static void fill_prstatus(struct elf_prstatus *prstatus,
1306 struct task_struct *p, long signr)
1308 prstatus->pr_info.si_signo = prstatus->pr_cursig = signr;
1309 prstatus->pr_sigpend = p->pending.signal.sig[0];
1310 prstatus->pr_sighold = p->blocked.sig[0];
1312 prstatus->pr_ppid = task_pid_vnr(rcu_dereference(p->real_parent));
1314 prstatus->pr_pid = task_pid_vnr(p);
1315 prstatus->pr_pgrp = task_pgrp_vnr(p);
1316 prstatus->pr_sid = task_session_vnr(p);
1317 if (thread_group_leader(p)) {
1318 struct task_cputime cputime;
1321 * This is the record for the group leader. It shows the
1322 * group-wide total, not its individual thread total.
1324 thread_group_cputime(p, &cputime);
1325 cputime_to_timeval(cputime.utime, &prstatus->pr_utime);
1326 cputime_to_timeval(cputime.stime, &prstatus->pr_stime);
1328 cputime_to_timeval(p->utime, &prstatus->pr_utime);
1329 cputime_to_timeval(p->stime, &prstatus->pr_stime);
1331 cputime_to_timeval(p->signal->cutime, &prstatus->pr_cutime);
1332 cputime_to_timeval(p->signal->cstime, &prstatus->pr_cstime);
1335 static int fill_psinfo(struct elf_prpsinfo *psinfo, struct task_struct *p,
1336 struct mm_struct *mm)
1338 const struct cred *cred;
1339 unsigned int i, len;
1341 /* first copy the parameters from user space */
1342 memset(psinfo, 0, sizeof(struct elf_prpsinfo));
1344 len = mm->arg_end - mm->arg_start;
1345 if (len >= ELF_PRARGSZ)
1346 len = ELF_PRARGSZ-1;
1347 if (copy_from_user(&psinfo->pr_psargs,
1348 (const char __user *)mm->arg_start, len))
1350 for(i = 0; i < len; i++)
1351 if (psinfo->pr_psargs[i] == 0)
1352 psinfo->pr_psargs[i] = ' ';
1353 psinfo->pr_psargs[len] = 0;
1356 psinfo->pr_ppid = task_pid_vnr(rcu_dereference(p->real_parent));
1358 psinfo->pr_pid = task_pid_vnr(p);
1359 psinfo->pr_pgrp = task_pgrp_vnr(p);
1360 psinfo->pr_sid = task_session_vnr(p);
1362 i = p->state ? ffz(~p->state) + 1 : 0;
1363 psinfo->pr_state = i;
1364 psinfo->pr_sname = (i > 5) ? '.' : "RSDTZW"[i];
1365 psinfo->pr_zomb = psinfo->pr_sname == 'Z';
1366 psinfo->pr_nice = task_nice(p);
1367 psinfo->pr_flag = p->flags;
1369 cred = __task_cred(p);
1370 SET_UID(psinfo->pr_uid, cred->uid);
1371 SET_GID(psinfo->pr_gid, cred->gid);
1373 strncpy(psinfo->pr_fname, p->comm, sizeof(psinfo->pr_fname));
1378 static void fill_auxv_note(struct memelfnote *note, struct mm_struct *mm)
1380 elf_addr_t *auxv = (elf_addr_t *) mm->saved_auxv;
1384 while (auxv[i - 2] != AT_NULL);
1385 fill_note(note, "CORE", NT_AUXV, i * sizeof(elf_addr_t), auxv);
1388 #ifdef CORE_DUMP_USE_REGSET
1389 #include <linux/regset.h>
1391 struct elf_thread_core_info {
1392 struct elf_thread_core_info *next;
1393 struct task_struct *task;
1394 struct elf_prstatus prstatus;
1395 struct memelfnote notes[0];
1398 struct elf_note_info {
1399 struct elf_thread_core_info *thread;
1400 struct memelfnote psinfo;
1401 struct memelfnote auxv;
1407 * When a regset has a writeback hook, we call it on each thread before
1408 * dumping user memory. On register window machines, this makes sure the
1409 * user memory backing the register data is up to date before we read it.
1411 static void do_thread_regset_writeback(struct task_struct *task,
1412 const struct user_regset *regset)
1414 if (regset->writeback)
1415 regset->writeback(task, regset, 1);
1418 static int fill_thread_core_info(struct elf_thread_core_info *t,
1419 const struct user_regset_view *view,
1420 long signr, size_t *total)
1425 * NT_PRSTATUS is the one special case, because the regset data
1426 * goes into the pr_reg field inside the note contents, rather
1427 * than being the whole note contents. We fill the reset in here.
1428 * We assume that regset 0 is NT_PRSTATUS.
1430 fill_prstatus(&t->prstatus, t->task, signr);
1431 (void) view->regsets[0].get(t->task, &view->regsets[0],
1432 0, sizeof(t->prstatus.pr_reg),
1433 &t->prstatus.pr_reg, NULL);
1435 fill_note(&t->notes[0], "CORE", NT_PRSTATUS,
1436 sizeof(t->prstatus), &t->prstatus);
1437 *total += notesize(&t->notes[0]);
1439 do_thread_regset_writeback(t->task, &view->regsets[0]);
1442 * Each other regset might generate a note too. For each regset
1443 * that has no core_note_type or is inactive, we leave t->notes[i]
1444 * all zero and we'll know to skip writing it later.
1446 for (i = 1; i < view->n; ++i) {
1447 const struct user_regset *regset = &view->regsets[i];
1448 do_thread_regset_writeback(t->task, regset);
1449 if (regset->core_note_type && regset->get &&
1450 (!regset->active || regset->active(t->task, regset))) {
1452 size_t size = regset->n * regset->size;
1453 void *data = kmalloc(size, GFP_KERNEL);
1454 if (unlikely(!data))
1456 ret = regset->get(t->task, regset,
1457 0, size, data, NULL);
1461 if (regset->core_note_type != NT_PRFPREG)
1462 fill_note(&t->notes[i], "LINUX",
1463 regset->core_note_type,
1466 t->prstatus.pr_fpvalid = 1;
1467 fill_note(&t->notes[i], "CORE",
1468 NT_PRFPREG, size, data);
1470 *total += notesize(&t->notes[i]);
1478 static int fill_note_info(struct elfhdr *elf, int phdrs,
1479 struct elf_note_info *info,
1480 long signr, struct pt_regs *regs)
1482 struct task_struct *dump_task = current;
1483 const struct user_regset_view *view = task_user_regset_view(dump_task);
1484 struct elf_thread_core_info *t;
1485 struct elf_prpsinfo *psinfo;
1486 struct core_thread *ct;
1490 info->thread = NULL;
1492 psinfo = kmalloc(sizeof(*psinfo), GFP_KERNEL);
1496 fill_note(&info->psinfo, "CORE", NT_PRPSINFO, sizeof(*psinfo), psinfo);
1499 * Figure out how many notes we're going to need for each thread.
1501 info->thread_notes = 0;
1502 for (i = 0; i < view->n; ++i)
1503 if (view->regsets[i].core_note_type != 0)
1504 ++info->thread_notes;
1507 * Sanity check. We rely on regset 0 being in NT_PRSTATUS,
1508 * since it is our one special case.
1510 if (unlikely(info->thread_notes == 0) ||
1511 unlikely(view->regsets[0].core_note_type != NT_PRSTATUS)) {
1517 * Initialize the ELF file header.
1519 fill_elf_header(elf, phdrs,
1520 view->e_machine, view->e_flags, view->ei_osabi);
1523 * Allocate a structure for each thread.
1525 for (ct = &dump_task->mm->core_state->dumper; ct; ct = ct->next) {
1526 t = kzalloc(offsetof(struct elf_thread_core_info,
1527 notes[info->thread_notes]),
1533 if (ct->task == dump_task || !info->thread) {
1534 t->next = info->thread;
1538 * Make sure to keep the original task at
1539 * the head of the list.
1541 t->next = info->thread->next;
1542 info->thread->next = t;
1547 * Now fill in each thread's information.
1549 for (t = info->thread; t != NULL; t = t->next)
1550 if (!fill_thread_core_info(t, view, signr, &info->size))
1554 * Fill in the two process-wide notes.
1556 fill_psinfo(psinfo, dump_task->group_leader, dump_task->mm);
1557 info->size += notesize(&info->psinfo);
1559 fill_auxv_note(&info->auxv, current->mm);
1560 info->size += notesize(&info->auxv);
1565 static size_t get_note_info_size(struct elf_note_info *info)
1571 * Write all the notes for each thread. When writing the first thread, the
1572 * process-wide notes are interleaved after the first thread-specific note.
1574 static int write_note_info(struct elf_note_info *info,
1575 struct file *file, loff_t *foffset)
1578 struct elf_thread_core_info *t = info->thread;
1583 if (!writenote(&t->notes[0], file, foffset))
1586 if (first && !writenote(&info->psinfo, file, foffset))
1588 if (first && !writenote(&info->auxv, file, foffset))
1591 for (i = 1; i < info->thread_notes; ++i)
1592 if (t->notes[i].data &&
1593 !writenote(&t->notes[i], file, foffset))
1603 static void free_note_info(struct elf_note_info *info)
1605 struct elf_thread_core_info *threads = info->thread;
1608 struct elf_thread_core_info *t = threads;
1610 WARN_ON(t->notes[0].data && t->notes[0].data != &t->prstatus);
1611 for (i = 1; i < info->thread_notes; ++i)
1612 kfree(t->notes[i].data);
1615 kfree(info->psinfo.data);
1620 /* Here is the structure in which status of each thread is captured. */
1621 struct elf_thread_status
1623 struct list_head list;
1624 struct elf_prstatus prstatus; /* NT_PRSTATUS */
1625 elf_fpregset_t fpu; /* NT_PRFPREG */
1626 struct task_struct *thread;
1627 #ifdef ELF_CORE_COPY_XFPREGS
1628 elf_fpxregset_t xfpu; /* ELF_CORE_XFPREG_TYPE */
1630 struct memelfnote notes[3];
1635 * In order to add the specific thread information for the elf file format,
1636 * we need to keep a linked list of every threads pr_status and then create
1637 * a single section for them in the final core file.
1639 static int elf_dump_thread_status(long signr, struct elf_thread_status *t)
1642 struct task_struct *p = t->thread;
1645 fill_prstatus(&t->prstatus, p, signr);
1646 elf_core_copy_task_regs(p, &t->prstatus.pr_reg);
1648 fill_note(&t->notes[0], "CORE", NT_PRSTATUS, sizeof(t->prstatus),
1651 sz += notesize(&t->notes[0]);
1653 if ((t->prstatus.pr_fpvalid = elf_core_copy_task_fpregs(p, NULL,
1655 fill_note(&t->notes[1], "CORE", NT_PRFPREG, sizeof(t->fpu),
1658 sz += notesize(&t->notes[1]);
1661 #ifdef ELF_CORE_COPY_XFPREGS
1662 if (elf_core_copy_task_xfpregs(p, &t->xfpu)) {
1663 fill_note(&t->notes[2], "LINUX", ELF_CORE_XFPREG_TYPE,
1664 sizeof(t->xfpu), &t->xfpu);
1666 sz += notesize(&t->notes[2]);
1672 struct elf_note_info {
1673 struct memelfnote *notes;
1674 struct elf_prstatus *prstatus; /* NT_PRSTATUS */
1675 struct elf_prpsinfo *psinfo; /* NT_PRPSINFO */
1676 struct list_head thread_list;
1677 elf_fpregset_t *fpu;
1678 #ifdef ELF_CORE_COPY_XFPREGS
1679 elf_fpxregset_t *xfpu;
1681 int thread_status_size;
1685 static int elf_note_info_init(struct elf_note_info *info)
1687 memset(info, 0, sizeof(*info));
1688 INIT_LIST_HEAD(&info->thread_list);
1690 /* Allocate space for six ELF notes */
1691 info->notes = kmalloc(6 * sizeof(struct memelfnote), GFP_KERNEL);
1694 info->psinfo = kmalloc(sizeof(*info->psinfo), GFP_KERNEL);
1697 info->prstatus = kmalloc(sizeof(*info->prstatus), GFP_KERNEL);
1698 if (!info->prstatus)
1700 info->fpu = kmalloc(sizeof(*info->fpu), GFP_KERNEL);
1703 #ifdef ELF_CORE_COPY_XFPREGS
1704 info->xfpu = kmalloc(sizeof(*info->xfpu), GFP_KERNEL);
1709 #ifdef ELF_CORE_COPY_XFPREGS
1714 kfree(info->prstatus);
1716 kfree(info->psinfo);
1722 static int fill_note_info(struct elfhdr *elf, int phdrs,
1723 struct elf_note_info *info,
1724 long signr, struct pt_regs *regs)
1726 struct list_head *t;
1728 if (!elf_note_info_init(info))
1732 struct core_thread *ct;
1733 struct elf_thread_status *ets;
1735 for (ct = current->mm->core_state->dumper.next;
1736 ct; ct = ct->next) {
1737 ets = kzalloc(sizeof(*ets), GFP_KERNEL);
1741 ets->thread = ct->task;
1742 list_add(&ets->list, &info->thread_list);
1745 list_for_each(t, &info->thread_list) {
1748 ets = list_entry(t, struct elf_thread_status, list);
1749 sz = elf_dump_thread_status(signr, ets);
1750 info->thread_status_size += sz;
1753 /* now collect the dump for the current */
1754 memset(info->prstatus, 0, sizeof(*info->prstatus));
1755 fill_prstatus(info->prstatus, current, signr);
1756 elf_core_copy_regs(&info->prstatus->pr_reg, regs);
1759 fill_elf_header(elf, phdrs, ELF_ARCH, ELF_CORE_EFLAGS, ELF_OSABI);
1762 * Set up the notes in similar form to SVR4 core dumps made
1763 * with info from their /proc.
1766 fill_note(info->notes + 0, "CORE", NT_PRSTATUS,
1767 sizeof(*info->prstatus), info->prstatus);
1768 fill_psinfo(info->psinfo, current->group_leader, current->mm);
1769 fill_note(info->notes + 1, "CORE", NT_PRPSINFO,
1770 sizeof(*info->psinfo), info->psinfo);
1774 fill_auxv_note(&info->notes[info->numnote++], current->mm);
1776 /* Try to dump the FPU. */
1777 info->prstatus->pr_fpvalid = elf_core_copy_task_fpregs(current, regs,
1779 if (info->prstatus->pr_fpvalid)
1780 fill_note(info->notes + info->numnote++,
1781 "CORE", NT_PRFPREG, sizeof(*info->fpu), info->fpu);
1782 #ifdef ELF_CORE_COPY_XFPREGS
1783 if (elf_core_copy_task_xfpregs(current, info->xfpu))
1784 fill_note(info->notes + info->numnote++,
1785 "LINUX", ELF_CORE_XFPREG_TYPE,
1786 sizeof(*info->xfpu), info->xfpu);
1792 static size_t get_note_info_size(struct elf_note_info *info)
1797 for (i = 0; i < info->numnote; i++)
1798 sz += notesize(info->notes + i);
1800 sz += info->thread_status_size;
1805 static int write_note_info(struct elf_note_info *info,
1806 struct file *file, loff_t *foffset)
1809 struct list_head *t;
1811 for (i = 0; i < info->numnote; i++)
1812 if (!writenote(info->notes + i, file, foffset))
1815 /* write out the thread status notes section */
1816 list_for_each(t, &info->thread_list) {
1817 struct elf_thread_status *tmp =
1818 list_entry(t, struct elf_thread_status, list);
1820 for (i = 0; i < tmp->num_notes; i++)
1821 if (!writenote(&tmp->notes[i], file, foffset))
1828 static void free_note_info(struct elf_note_info *info)
1830 while (!list_empty(&info->thread_list)) {
1831 struct list_head *tmp = info->thread_list.next;
1833 kfree(list_entry(tmp, struct elf_thread_status, list));
1836 kfree(info->prstatus);
1837 kfree(info->psinfo);
1840 #ifdef ELF_CORE_COPY_XFPREGS
1847 static struct vm_area_struct *first_vma(struct task_struct *tsk,
1848 struct vm_area_struct *gate_vma)
1850 struct vm_area_struct *ret = tsk->mm->mmap;
1857 * Helper function for iterating across a vma list. It ensures that the caller
1858 * will visit `gate_vma' prior to terminating the search.
1860 static struct vm_area_struct *next_vma(struct vm_area_struct *this_vma,
1861 struct vm_area_struct *gate_vma)
1863 struct vm_area_struct *ret;
1865 ret = this_vma->vm_next;
1868 if (this_vma == gate_vma)
1873 static void fill_extnum_info(struct elfhdr *elf, struct elf_shdr *shdr4extnum,
1874 elf_addr_t e_shoff, int segs)
1876 elf->e_shoff = e_shoff;
1877 elf->e_shentsize = sizeof(*shdr4extnum);
1879 elf->e_shstrndx = SHN_UNDEF;
1881 memset(shdr4extnum, 0, sizeof(*shdr4extnum));
1883 shdr4extnum->sh_type = SHT_NULL;
1884 shdr4extnum->sh_size = elf->e_shnum;
1885 shdr4extnum->sh_link = elf->e_shstrndx;
1886 shdr4extnum->sh_info = segs;
1889 static size_t elf_core_vma_data_size(struct vm_area_struct *gate_vma,
1890 unsigned long mm_flags)
1892 struct vm_area_struct *vma;
1895 for (vma = first_vma(current, gate_vma); vma != NULL;
1896 vma = next_vma(vma, gate_vma))
1897 size += vma_dump_size(vma, mm_flags);
1904 * This is a two-pass process; first we find the offsets of the bits,
1905 * and then they are actually written out. If we run out of core limit
1908 static int elf_core_dump(struct coredump_params *cprm)
1914 struct vm_area_struct *vma, *gate_vma;
1915 struct elfhdr *elf = NULL;
1916 loff_t offset = 0, dataoff, foffset;
1917 struct elf_note_info info;
1918 struct elf_phdr *phdr4note = NULL;
1919 struct elf_shdr *shdr4extnum = NULL;
1924 * We no longer stop all VM operations.
1926 * This is because those proceses that could possibly change map_count
1927 * or the mmap / vma pages are now blocked in do_exit on current
1928 * finishing this core dump.
1930 * Only ptrace can touch these memory addresses, but it doesn't change
1931 * the map_count or the pages allocated. So no possibility of crashing
1932 * exists while dumping the mm->vm_next areas to the core file.
1935 /* alloc memory for large data structures: too large to be on stack */
1936 elf = kmalloc(sizeof(*elf), GFP_KERNEL);
1940 * The number of segs are recored into ELF header as 16bit value.
1941 * Please check DEFAULT_MAX_MAP_COUNT definition when you modify here.
1943 segs = current->mm->map_count;
1944 segs += elf_core_extra_phdrs();
1946 gate_vma = get_gate_vma(current->mm);
1947 if (gate_vma != NULL)
1950 /* for notes section */
1953 /* If segs > PN_XNUM(0xffff), then e_phnum overflows. To avoid
1954 * this, kernel supports extended numbering. Have a look at
1955 * include/linux/elf.h for further information. */
1956 e_phnum = segs > PN_XNUM ? PN_XNUM : segs;
1959 * Collect all the non-memory information about the process for the
1960 * notes. This also sets up the file header.
1962 if (!fill_note_info(elf, e_phnum, &info, cprm->signr, cprm->regs))
1966 current->flags |= PF_DUMPCORE;
1971 offset += sizeof(*elf); /* Elf header */
1972 offset += segs * sizeof(struct elf_phdr); /* Program headers */
1975 /* Write notes phdr entry */
1977 size_t sz = get_note_info_size(&info);
1979 sz += elf_coredump_extra_notes_size();
1981 phdr4note = kmalloc(sizeof(*phdr4note), GFP_KERNEL);
1985 fill_elf_note_phdr(phdr4note, sz, offset);
1989 dataoff = offset = roundup(offset, ELF_EXEC_PAGESIZE);
1991 offset += elf_core_vma_data_size(gate_vma, cprm->mm_flags);
1992 offset += elf_core_extra_data_size();
1995 if (e_phnum == PN_XNUM) {
1996 shdr4extnum = kmalloc(sizeof(*shdr4extnum), GFP_KERNEL);
1999 fill_extnum_info(elf, shdr4extnum, e_shoff, segs);
2004 size += sizeof(*elf);
2005 if (size > cprm->limit || !dump_write(cprm->file, elf, sizeof(*elf)))
2008 size += sizeof(*phdr4note);
2009 if (size > cprm->limit
2010 || !dump_write(cprm->file, phdr4note, sizeof(*phdr4note)))
2013 /* Write program headers for segments dump */
2014 for (vma = first_vma(current, gate_vma); vma != NULL;
2015 vma = next_vma(vma, gate_vma)) {
2016 struct elf_phdr phdr;
2018 phdr.p_type = PT_LOAD;
2019 phdr.p_offset = offset;
2020 phdr.p_vaddr = vma->vm_start;
2022 phdr.p_filesz = vma_dump_size(vma, cprm->mm_flags);
2023 phdr.p_memsz = vma->vm_end - vma->vm_start;
2024 offset += phdr.p_filesz;
2025 phdr.p_flags = vma->vm_flags & VM_READ ? PF_R : 0;
2026 if (vma->vm_flags & VM_WRITE)
2027 phdr.p_flags |= PF_W;
2028 if (vma->vm_flags & VM_EXEC)
2029 phdr.p_flags |= PF_X;
2030 phdr.p_align = ELF_EXEC_PAGESIZE;
2032 size += sizeof(phdr);
2033 if (size > cprm->limit
2034 || !dump_write(cprm->file, &phdr, sizeof(phdr)))
2038 if (!elf_core_write_extra_phdrs(cprm->file, offset, &size, cprm->limit))
2041 /* write out the notes section */
2042 if (!write_note_info(&info, cprm->file, &foffset))
2045 if (elf_coredump_extra_notes_write(cprm->file, &foffset))
2049 if (!dump_seek(cprm->file, dataoff - foffset))
2052 for (vma = first_vma(current, gate_vma); vma != NULL;
2053 vma = next_vma(vma, gate_vma)) {
2057 end = vma->vm_start + vma_dump_size(vma, cprm->mm_flags);
2059 for (addr = vma->vm_start; addr < end; addr += PAGE_SIZE) {
2063 page = get_dump_page(addr);
2065 void *kaddr = kmap(page);
2066 stop = ((size += PAGE_SIZE) > cprm->limit) ||
2067 !dump_write(cprm->file, kaddr,
2070 page_cache_release(page);
2072 stop = !dump_seek(cprm->file, PAGE_SIZE);
2078 if (!elf_core_write_extra_data(cprm->file, &size, cprm->limit))
2081 if (e_phnum == PN_XNUM) {
2082 size += sizeof(*shdr4extnum);
2083 if (size > cprm->limit
2084 || !dump_write(cprm->file, shdr4extnum,
2085 sizeof(*shdr4extnum)))
2093 free_note_info(&info);
2101 #endif /* CONFIG_ELF_CORE */
2103 static int __init init_elf_binfmt(void)
2105 register_binfmt(&elf_format);
2109 static void __exit exit_elf_binfmt(void)
2111 /* Remove the COFF and ELF loaders. */
2112 unregister_binfmt(&elf_format);
2115 core_initcall(init_elf_binfmt);
2116 module_exit(exit_elf_binfmt);
2117 MODULE_LICENSE("GPL");