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/vmalloc.h>
31 #include <linux/security.h>
32 #include <linux/random.h>
33 #include <linux/elf.h>
34 #include <linux/elf-randomize.h>
35 #include <linux/utsname.h>
36 #include <linux/coredump.h>
37 #include <linux/sched.h>
38 #include <linux/sched/coredump.h>
39 #include <linux/sched/task_stack.h>
40 #include <linux/sched/cputime.h>
41 #include <linux/cred.h>
42 #include <linux/dax.h>
43 #include <linux/uaccess.h>
44 #include <asm/param.h>
48 #define user_long_t long
50 #ifndef user_siginfo_t
51 #define user_siginfo_t siginfo_t
54 /* That's for binfmt_elf_fdpic to deal with */
55 #ifndef elf_check_fdpic
56 #define elf_check_fdpic(ex) false
59 static int load_elf_binary(struct linux_binprm *bprm);
60 static unsigned long elf_map(struct file *, unsigned long, struct elf_phdr *,
61 int, int, unsigned long);
64 static int load_elf_library(struct file *);
66 #define load_elf_library NULL
70 * If we don't support core dumping, then supply a NULL so we
73 #ifdef CONFIG_ELF_CORE
74 static int elf_core_dump(struct coredump_params *cprm);
76 #define elf_core_dump NULL
79 #if ELF_EXEC_PAGESIZE > PAGE_SIZE
80 #define ELF_MIN_ALIGN ELF_EXEC_PAGESIZE
82 #define ELF_MIN_ALIGN PAGE_SIZE
85 #ifndef ELF_CORE_EFLAGS
86 #define ELF_CORE_EFLAGS 0
89 #define ELF_PAGESTART(_v) ((_v) & ~(unsigned long)(ELF_MIN_ALIGN-1))
90 #define ELF_PAGEOFFSET(_v) ((_v) & (ELF_MIN_ALIGN-1))
91 #define ELF_PAGEALIGN(_v) (((_v) + ELF_MIN_ALIGN - 1) & ~(ELF_MIN_ALIGN - 1))
93 static struct linux_binfmt elf_format = {
94 .module = THIS_MODULE,
95 .load_binary = load_elf_binary,
96 .load_shlib = load_elf_library,
97 .core_dump = elf_core_dump,
98 .min_coredump = ELF_EXEC_PAGESIZE,
101 #define BAD_ADDR(x) ((unsigned long)(x) >= TASK_SIZE)
103 static int set_brk(unsigned long start, unsigned long end, int prot)
105 start = ELF_PAGEALIGN(start);
106 end = ELF_PAGEALIGN(end);
109 * Map the last of the bss segment.
110 * If the header is requesting these pages to be
111 * executable, honour that (ppc32 needs this).
113 int error = vm_brk_flags(start, end - start,
114 prot & PROT_EXEC ? VM_EXEC : 0);
118 current->mm->start_brk = current->mm->brk = end;
122 /* We need to explicitly zero any fractional pages
123 after the data section (i.e. bss). This would
124 contain the junk from the file that should not
127 static int padzero(unsigned long elf_bss)
131 nbyte = ELF_PAGEOFFSET(elf_bss);
133 nbyte = ELF_MIN_ALIGN - nbyte;
134 if (clear_user((void __user *) elf_bss, nbyte))
140 /* Let's use some macros to make this stack manipulation a little clearer */
141 #ifdef CONFIG_STACK_GROWSUP
142 #define STACK_ADD(sp, items) ((elf_addr_t __user *)(sp) + (items))
143 #define STACK_ROUND(sp, items) \
144 ((15 + (unsigned long) ((sp) + (items))) &~ 15UL)
145 #define STACK_ALLOC(sp, len) ({ \
146 elf_addr_t __user *old_sp = (elf_addr_t __user *)sp; sp += len; \
149 #define STACK_ADD(sp, items) ((elf_addr_t __user *)(sp) - (items))
150 #define STACK_ROUND(sp, items) \
151 (((unsigned long) (sp - items)) &~ 15UL)
152 #define STACK_ALLOC(sp, len) ({ sp -= len ; sp; })
155 #ifndef ELF_BASE_PLATFORM
157 * AT_BASE_PLATFORM indicates the "real" hardware/microarchitecture.
158 * If the arch defines ELF_BASE_PLATFORM (in asm/elf.h), the value
159 * will be copied to the user stack in the same manner as AT_PLATFORM.
161 #define ELF_BASE_PLATFORM NULL
165 create_elf_tables(struct linux_binprm *bprm, struct elfhdr *exec,
166 unsigned long load_addr, unsigned long interp_load_addr)
168 unsigned long p = bprm->p;
169 int argc = bprm->argc;
170 int envc = bprm->envc;
171 elf_addr_t __user *sp;
172 elf_addr_t __user *u_platform;
173 elf_addr_t __user *u_base_platform;
174 elf_addr_t __user *u_rand_bytes;
175 const char *k_platform = ELF_PLATFORM;
176 const char *k_base_platform = ELF_BASE_PLATFORM;
177 unsigned char k_rand_bytes[16];
179 elf_addr_t *elf_info;
181 const struct cred *cred = current_cred();
182 struct vm_area_struct *vma;
185 * In some cases (e.g. Hyper-Threading), we want to avoid L1
186 * evictions by the processes running on the same package. One
187 * thing we can do is to shuffle the initial stack for them.
190 p = arch_align_stack(p);
193 * If this architecture has a platform capability string, copy it
194 * to userspace. In some cases (Sparc), this info is impossible
195 * for userspace to get any other way, in others (i386) it is
200 size_t len = strlen(k_platform) + 1;
202 u_platform = (elf_addr_t __user *)STACK_ALLOC(p, len);
203 if (__copy_to_user(u_platform, k_platform, len))
208 * If this architecture has a "base" platform capability
209 * string, copy it to userspace.
211 u_base_platform = NULL;
212 if (k_base_platform) {
213 size_t len = strlen(k_base_platform) + 1;
215 u_base_platform = (elf_addr_t __user *)STACK_ALLOC(p, len);
216 if (__copy_to_user(u_base_platform, k_base_platform, len))
221 * Generate 16 random bytes for userspace PRNG seeding.
223 get_random_bytes(k_rand_bytes, sizeof(k_rand_bytes));
224 u_rand_bytes = (elf_addr_t __user *)
225 STACK_ALLOC(p, sizeof(k_rand_bytes));
226 if (__copy_to_user(u_rand_bytes, k_rand_bytes, sizeof(k_rand_bytes)))
229 /* Create the ELF interpreter info */
230 elf_info = (elf_addr_t *)current->mm->saved_auxv;
231 /* update AT_VECTOR_SIZE_BASE if the number of NEW_AUX_ENT() changes */
232 #define NEW_AUX_ENT(id, val) \
234 elf_info[ei_index++] = id; \
235 elf_info[ei_index++] = val; \
240 * ARCH_DLINFO must come first so PPC can do its special alignment of
242 * update AT_VECTOR_SIZE_ARCH if the number of NEW_AUX_ENT() in
243 * ARCH_DLINFO changes
247 NEW_AUX_ENT(AT_HWCAP, ELF_HWCAP);
248 NEW_AUX_ENT(AT_PAGESZ, ELF_EXEC_PAGESIZE);
249 NEW_AUX_ENT(AT_CLKTCK, CLOCKS_PER_SEC);
250 NEW_AUX_ENT(AT_PHDR, load_addr + exec->e_phoff);
251 NEW_AUX_ENT(AT_PHENT, sizeof(struct elf_phdr));
252 NEW_AUX_ENT(AT_PHNUM, exec->e_phnum);
253 NEW_AUX_ENT(AT_BASE, interp_load_addr);
254 NEW_AUX_ENT(AT_FLAGS, 0);
255 NEW_AUX_ENT(AT_ENTRY, exec->e_entry);
256 NEW_AUX_ENT(AT_UID, from_kuid_munged(cred->user_ns, cred->uid));
257 NEW_AUX_ENT(AT_EUID, from_kuid_munged(cred->user_ns, cred->euid));
258 NEW_AUX_ENT(AT_GID, from_kgid_munged(cred->user_ns, cred->gid));
259 NEW_AUX_ENT(AT_EGID, from_kgid_munged(cred->user_ns, cred->egid));
260 NEW_AUX_ENT(AT_SECURE, bprm->secureexec);
261 NEW_AUX_ENT(AT_RANDOM, (elf_addr_t)(unsigned long)u_rand_bytes);
263 NEW_AUX_ENT(AT_HWCAP2, ELF_HWCAP2);
265 NEW_AUX_ENT(AT_EXECFN, bprm->exec);
267 NEW_AUX_ENT(AT_PLATFORM,
268 (elf_addr_t)(unsigned long)u_platform);
270 if (k_base_platform) {
271 NEW_AUX_ENT(AT_BASE_PLATFORM,
272 (elf_addr_t)(unsigned long)u_base_platform);
274 if (bprm->interp_flags & BINPRM_FLAGS_EXECFD) {
275 NEW_AUX_ENT(AT_EXECFD, bprm->interp_data);
278 /* AT_NULL is zero; clear the rest too */
279 memset(&elf_info[ei_index], 0,
280 sizeof current->mm->saved_auxv - ei_index * sizeof elf_info[0]);
282 /* And advance past the AT_NULL entry. */
285 sp = STACK_ADD(p, ei_index);
287 items = (argc + 1) + (envc + 1) + 1;
288 bprm->p = STACK_ROUND(sp, items);
290 /* Point sp at the lowest address on the stack */
291 #ifdef CONFIG_STACK_GROWSUP
292 sp = (elf_addr_t __user *)bprm->p - items - ei_index;
293 bprm->exec = (unsigned long)sp; /* XXX: PARISC HACK */
295 sp = (elf_addr_t __user *)bprm->p;
300 * Grow the stack manually; some architectures have a limit on how
301 * far ahead a user-space access may be in order to grow the stack.
303 vma = find_extend_vma(current->mm, bprm->p);
307 /* Now, let's put argc (and argv, envp if appropriate) on the stack */
308 if (__put_user(argc, sp++))
311 /* Populate list of argv pointers back to argv strings. */
312 p = current->mm->arg_end = current->mm->arg_start;
315 if (__put_user((elf_addr_t)p, sp++))
317 len = strnlen_user((void __user *)p, MAX_ARG_STRLEN);
318 if (!len || len > MAX_ARG_STRLEN)
322 if (__put_user(0, sp++))
324 current->mm->arg_end = p;
326 /* Populate list of envp pointers back to envp strings. */
327 current->mm->env_end = current->mm->env_start = p;
330 if (__put_user((elf_addr_t)p, sp++))
332 len = strnlen_user((void __user *)p, MAX_ARG_STRLEN);
333 if (!len || len > MAX_ARG_STRLEN)
337 if (__put_user(0, sp++))
339 current->mm->env_end = p;
341 /* Put the elf_info on the stack in the right place. */
342 if (copy_to_user(sp, elf_info, ei_index * sizeof(elf_addr_t)))
349 static unsigned long elf_map(struct file *filep, unsigned long addr,
350 struct elf_phdr *eppnt, int prot, int type,
351 unsigned long total_size)
353 unsigned long map_addr;
354 unsigned long size = eppnt->p_filesz + ELF_PAGEOFFSET(eppnt->p_vaddr);
355 unsigned long off = eppnt->p_offset - ELF_PAGEOFFSET(eppnt->p_vaddr);
356 addr = ELF_PAGESTART(addr);
357 size = ELF_PAGEALIGN(size);
359 /* mmap() will return -EINVAL if given a zero size, but a
360 * segment with zero filesize is perfectly valid */
365 * total_size is the size of the ELF (interpreter) image.
366 * The _first_ mmap needs to know the full size, otherwise
367 * randomization might put this image into an overlapping
368 * position with the ELF binary image. (since size < total_size)
369 * So we first map the 'big' image - and unmap the remainder at
370 * the end. (which unmap is needed for ELF images with holes.)
373 total_size = ELF_PAGEALIGN(total_size);
374 map_addr = vm_mmap(filep, addr, total_size, prot, type, off);
375 if (!BAD_ADDR(map_addr))
376 vm_munmap(map_addr+size, total_size-size);
378 map_addr = vm_mmap(filep, addr, size, prot, type, off);
380 if ((type & MAP_FIXED_NOREPLACE) &&
381 PTR_ERR((void *)map_addr) == -EEXIST)
382 pr_info("%d (%s): Uhuuh, elf segment at %px requested but the memory is mapped already\n",
383 task_pid_nr(current), current->comm, (void *)addr);
388 #endif /* !elf_map */
390 static unsigned long total_mapping_size(struct elf_phdr *cmds, int nr)
392 int i, first_idx = -1, last_idx = -1;
394 for (i = 0; i < nr; i++) {
395 if (cmds[i].p_type == PT_LOAD) {
404 return cmds[last_idx].p_vaddr + cmds[last_idx].p_memsz -
405 ELF_PAGESTART(cmds[first_idx].p_vaddr);
409 * load_elf_phdrs() - load ELF program headers
410 * @elf_ex: ELF header of the binary whose program headers should be loaded
411 * @elf_file: the opened ELF binary file
413 * Loads ELF program headers from the binary file elf_file, which has the ELF
414 * header pointed to by elf_ex, into a newly allocated array. The caller is
415 * responsible for freeing the allocated data. Returns an ERR_PTR upon failure.
417 static struct elf_phdr *load_elf_phdrs(struct elfhdr *elf_ex,
418 struct file *elf_file)
420 struct elf_phdr *elf_phdata = NULL;
421 int retval, size, err = -1;
422 loff_t pos = elf_ex->e_phoff;
425 * If the size of this structure has changed, then punt, since
426 * we will be doing the wrong thing.
428 if (elf_ex->e_phentsize != sizeof(struct elf_phdr))
431 /* Sanity check the number of program headers... */
432 if (elf_ex->e_phnum < 1 ||
433 elf_ex->e_phnum > 65536U / sizeof(struct elf_phdr))
436 /* ...and their total size. */
437 size = sizeof(struct elf_phdr) * elf_ex->e_phnum;
438 if (size > ELF_MIN_ALIGN)
441 elf_phdata = kmalloc(size, GFP_KERNEL);
445 /* Read in the program headers */
446 retval = kernel_read(elf_file, elf_phdata, size, &pos);
447 if (retval != size) {
448 err = (retval < 0) ? retval : -EIO;
462 #ifndef CONFIG_ARCH_BINFMT_ELF_STATE
465 * struct arch_elf_state - arch-specific ELF loading state
467 * This structure is used to preserve architecture specific data during
468 * the loading of an ELF file, throughout the checking of architecture
469 * specific ELF headers & through to the point where the ELF load is
470 * known to be proceeding (ie. SET_PERSONALITY).
472 * This implementation is a dummy for architectures which require no
475 struct arch_elf_state {
478 #define INIT_ARCH_ELF_STATE {}
481 * arch_elf_pt_proc() - check a PT_LOPROC..PT_HIPROC ELF program header
482 * @ehdr: The main ELF header
483 * @phdr: The program header to check
484 * @elf: The open ELF file
485 * @is_interp: True if the phdr is from the interpreter of the ELF being
486 * loaded, else false.
487 * @state: Architecture-specific state preserved throughout the process
488 * of loading the ELF.
490 * Inspects the program header phdr to validate its correctness and/or
491 * suitability for the system. Called once per ELF program header in the
492 * range PT_LOPROC to PT_HIPROC, for both the ELF being loaded and its
495 * Return: Zero to proceed with the ELF load, non-zero to fail the ELF load
496 * with that return code.
498 static inline int arch_elf_pt_proc(struct elfhdr *ehdr,
499 struct elf_phdr *phdr,
500 struct file *elf, bool is_interp,
501 struct arch_elf_state *state)
503 /* Dummy implementation, always proceed */
508 * arch_check_elf() - check an ELF executable
509 * @ehdr: The main ELF header
510 * @has_interp: True if the ELF has an interpreter, else false.
511 * @interp_ehdr: The interpreter's ELF header
512 * @state: Architecture-specific state preserved throughout the process
513 * of loading the ELF.
515 * Provides a final opportunity for architecture code to reject the loading
516 * of the ELF & cause an exec syscall to return an error. This is called after
517 * all program headers to be checked by arch_elf_pt_proc have been.
519 * Return: Zero to proceed with the ELF load, non-zero to fail the ELF load
520 * with that return code.
522 static inline int arch_check_elf(struct elfhdr *ehdr, bool has_interp,
523 struct elfhdr *interp_ehdr,
524 struct arch_elf_state *state)
526 /* Dummy implementation, always proceed */
530 #endif /* !CONFIG_ARCH_BINFMT_ELF_STATE */
532 /* This is much more generalized than the library routine read function,
533 so we keep this separate. Technically the library read function
534 is only provided so that we can read a.out libraries that have
537 static unsigned long load_elf_interp(struct elfhdr *interp_elf_ex,
538 struct file *interpreter, unsigned long *interp_map_addr,
539 unsigned long no_base, struct elf_phdr *interp_elf_phdata)
541 struct elf_phdr *eppnt;
542 unsigned long load_addr = 0;
543 int load_addr_set = 0;
544 unsigned long last_bss = 0, elf_bss = 0;
546 unsigned long error = ~0UL;
547 unsigned long total_size;
550 /* First of all, some simple consistency checks */
551 if (interp_elf_ex->e_type != ET_EXEC &&
552 interp_elf_ex->e_type != ET_DYN)
554 if (!elf_check_arch(interp_elf_ex) ||
555 elf_check_fdpic(interp_elf_ex))
557 if (!interpreter->f_op->mmap)
560 total_size = total_mapping_size(interp_elf_phdata,
561 interp_elf_ex->e_phnum);
567 eppnt = interp_elf_phdata;
568 for (i = 0; i < interp_elf_ex->e_phnum; i++, eppnt++) {
569 if (eppnt->p_type == PT_LOAD) {
570 int elf_type = MAP_PRIVATE | MAP_DENYWRITE;
572 unsigned long vaddr = 0;
573 unsigned long k, map_addr;
575 if (eppnt->p_flags & PF_R)
576 elf_prot = PROT_READ;
577 if (eppnt->p_flags & PF_W)
578 elf_prot |= PROT_WRITE;
579 if (eppnt->p_flags & PF_X)
580 elf_prot |= PROT_EXEC;
581 vaddr = eppnt->p_vaddr;
582 if (interp_elf_ex->e_type == ET_EXEC || load_addr_set)
583 elf_type |= MAP_FIXED_NOREPLACE;
584 else if (no_base && interp_elf_ex->e_type == ET_DYN)
587 map_addr = elf_map(interpreter, load_addr + vaddr,
588 eppnt, elf_prot, elf_type, total_size);
590 if (!*interp_map_addr)
591 *interp_map_addr = map_addr;
593 if (BAD_ADDR(map_addr))
596 if (!load_addr_set &&
597 interp_elf_ex->e_type == ET_DYN) {
598 load_addr = map_addr - ELF_PAGESTART(vaddr);
603 * Check to see if the section's size will overflow the
604 * allowed task size. Note that p_filesz must always be
605 * <= p_memsize so it's only necessary to check p_memsz.
607 k = load_addr + eppnt->p_vaddr;
609 eppnt->p_filesz > eppnt->p_memsz ||
610 eppnt->p_memsz > TASK_SIZE ||
611 TASK_SIZE - eppnt->p_memsz < k) {
617 * Find the end of the file mapping for this phdr, and
618 * keep track of the largest address we see for this.
620 k = load_addr + eppnt->p_vaddr + eppnt->p_filesz;
625 * Do the same thing for the memory mapping - between
626 * elf_bss and last_bss is the bss section.
628 k = load_addr + eppnt->p_vaddr + eppnt->p_memsz;
637 * Now fill out the bss section: first pad the last page from
638 * the file up to the page boundary, and zero it from elf_bss
639 * up to the end of the page.
641 if (padzero(elf_bss)) {
646 * Next, align both the file and mem bss up to the page size,
647 * since this is where elf_bss was just zeroed up to, and where
648 * last_bss will end after the vm_brk_flags() below.
650 elf_bss = ELF_PAGEALIGN(elf_bss);
651 last_bss = ELF_PAGEALIGN(last_bss);
652 /* Finally, if there is still more bss to allocate, do it. */
653 if (last_bss > elf_bss) {
654 error = vm_brk_flags(elf_bss, last_bss - elf_bss,
655 bss_prot & PROT_EXEC ? VM_EXEC : 0);
666 * These are the functions used to load ELF style executables and shared
667 * libraries. There is no binary dependent code anywhere else.
670 #ifndef STACK_RND_MASK
671 #define STACK_RND_MASK (0x7ff >> (PAGE_SHIFT - 12)) /* 8MB of VA */
674 static unsigned long randomize_stack_top(unsigned long stack_top)
676 unsigned long random_variable = 0;
678 if (current->flags & PF_RANDOMIZE) {
679 random_variable = get_random_long();
680 random_variable &= STACK_RND_MASK;
681 random_variable <<= PAGE_SHIFT;
683 #ifdef CONFIG_STACK_GROWSUP
684 return PAGE_ALIGN(stack_top) + random_variable;
686 return PAGE_ALIGN(stack_top) - random_variable;
690 static int load_elf_binary(struct linux_binprm *bprm)
692 struct file *interpreter = NULL; /* to shut gcc up */
693 unsigned long load_addr = 0, load_bias = 0;
694 int load_addr_set = 0;
695 char * elf_interpreter = NULL;
697 struct elf_phdr *elf_ppnt, *elf_phdata, *interp_elf_phdata = NULL;
698 unsigned long elf_bss, elf_brk;
701 unsigned long elf_entry;
702 unsigned long interp_load_addr = 0;
703 unsigned long start_code, end_code, start_data, end_data;
704 unsigned long reloc_func_desc __maybe_unused = 0;
705 int executable_stack = EXSTACK_DEFAULT;
706 struct pt_regs *regs = current_pt_regs();
708 struct elfhdr elf_ex;
709 struct elfhdr interp_elf_ex;
711 struct arch_elf_state arch_state = INIT_ARCH_ELF_STATE;
714 loc = kmalloc(sizeof(*loc), GFP_KERNEL);
720 /* Get the exec-header */
721 loc->elf_ex = *((struct elfhdr *)bprm->buf);
724 /* First of all, some simple consistency checks */
725 if (memcmp(loc->elf_ex.e_ident, ELFMAG, SELFMAG) != 0)
728 if (loc->elf_ex.e_type != ET_EXEC && loc->elf_ex.e_type != ET_DYN)
730 if (!elf_check_arch(&loc->elf_ex))
732 if (elf_check_fdpic(&loc->elf_ex))
734 if (!bprm->file->f_op->mmap)
737 elf_phdata = load_elf_phdrs(&loc->elf_ex, bprm->file);
741 elf_ppnt = elf_phdata;
750 for (i = 0; i < loc->elf_ex.e_phnum; i++) {
751 if (elf_ppnt->p_type == PT_INTERP) {
752 /* This is the program interpreter used for
753 * shared libraries - for now assume that this
754 * is an a.out format binary
757 if (elf_ppnt->p_filesz > PATH_MAX ||
758 elf_ppnt->p_filesz < 2)
762 elf_interpreter = kmalloc(elf_ppnt->p_filesz,
764 if (!elf_interpreter)
767 pos = elf_ppnt->p_offset;
768 retval = kernel_read(bprm->file, elf_interpreter,
769 elf_ppnt->p_filesz, &pos);
770 if (retval != elf_ppnt->p_filesz) {
773 goto out_free_interp;
775 /* make sure path is NULL terminated */
777 if (elf_interpreter[elf_ppnt->p_filesz - 1] != '\0')
778 goto out_free_interp;
780 interpreter = open_exec(elf_interpreter);
781 retval = PTR_ERR(interpreter);
782 if (IS_ERR(interpreter))
783 goto out_free_interp;
786 * If the binary is not readable then enforce
787 * mm->dumpable = 0 regardless of the interpreter's
790 would_dump(bprm, interpreter);
792 /* Get the exec headers */
794 retval = kernel_read(interpreter, &loc->interp_elf_ex,
795 sizeof(loc->interp_elf_ex), &pos);
796 if (retval != sizeof(loc->interp_elf_ex)) {
799 goto out_free_dentry;
807 elf_ppnt = elf_phdata;
808 for (i = 0; i < loc->elf_ex.e_phnum; i++, elf_ppnt++)
809 switch (elf_ppnt->p_type) {
811 if (elf_ppnt->p_flags & PF_X)
812 executable_stack = EXSTACK_ENABLE_X;
814 executable_stack = EXSTACK_DISABLE_X;
817 case PT_LOPROC ... PT_HIPROC:
818 retval = arch_elf_pt_proc(&loc->elf_ex, elf_ppnt,
822 goto out_free_dentry;
826 /* Some simple consistency checks for the interpreter */
827 if (elf_interpreter) {
829 /* Not an ELF interpreter */
830 if (memcmp(loc->interp_elf_ex.e_ident, ELFMAG, SELFMAG) != 0)
831 goto out_free_dentry;
832 /* Verify the interpreter has a valid arch */
833 if (!elf_check_arch(&loc->interp_elf_ex) ||
834 elf_check_fdpic(&loc->interp_elf_ex))
835 goto out_free_dentry;
837 /* Load the interpreter program headers */
838 interp_elf_phdata = load_elf_phdrs(&loc->interp_elf_ex,
840 if (!interp_elf_phdata)
841 goto out_free_dentry;
843 /* Pass PT_LOPROC..PT_HIPROC headers to arch code */
844 elf_ppnt = interp_elf_phdata;
845 for (i = 0; i < loc->interp_elf_ex.e_phnum; i++, elf_ppnt++)
846 switch (elf_ppnt->p_type) {
847 case PT_LOPROC ... PT_HIPROC:
848 retval = arch_elf_pt_proc(&loc->interp_elf_ex,
849 elf_ppnt, interpreter,
852 goto out_free_dentry;
858 * Allow arch code to reject the ELF at this point, whilst it's
859 * still possible to return an error to the code that invoked
862 retval = arch_check_elf(&loc->elf_ex,
863 !!interpreter, &loc->interp_elf_ex,
866 goto out_free_dentry;
868 /* Flush all traces of the currently running executable */
869 retval = flush_old_exec(bprm);
871 goto out_free_dentry;
873 /* Do this immediately, since STACK_TOP as used in setup_arg_pages
874 may depend on the personality. */
875 SET_PERSONALITY2(loc->elf_ex, &arch_state);
876 if (elf_read_implies_exec(loc->elf_ex, executable_stack))
877 current->personality |= READ_IMPLIES_EXEC;
879 if (!(current->personality & ADDR_NO_RANDOMIZE) && randomize_va_space)
880 current->flags |= PF_RANDOMIZE;
882 setup_new_exec(bprm);
883 install_exec_creds(bprm);
885 /* Do this so that we can load the interpreter, if need be. We will
886 change some of these later */
887 retval = setup_arg_pages(bprm, randomize_stack_top(STACK_TOP),
890 goto out_free_dentry;
892 current->mm->start_stack = bprm->p;
894 /* Now we do a little grungy work by mmapping the ELF image into
895 the correct location in memory. */
896 for(i = 0, elf_ppnt = elf_phdata;
897 i < loc->elf_ex.e_phnum; i++, elf_ppnt++) {
898 int elf_prot = 0, elf_flags, elf_fixed = MAP_FIXED_NOREPLACE;
899 unsigned long k, vaddr;
900 unsigned long total_size = 0;
902 if (elf_ppnt->p_type != PT_LOAD)
905 if (unlikely (elf_brk > elf_bss)) {
908 /* There was a PT_LOAD segment with p_memsz > p_filesz
909 before this one. Map anonymous pages, if needed,
910 and clear the area. */
911 retval = set_brk(elf_bss + load_bias,
915 goto out_free_dentry;
916 nbyte = ELF_PAGEOFFSET(elf_bss);
918 nbyte = ELF_MIN_ALIGN - nbyte;
919 if (nbyte > elf_brk - elf_bss)
920 nbyte = elf_brk - elf_bss;
921 if (clear_user((void __user *)elf_bss +
924 * This bss-zeroing can fail if the ELF
925 * file specifies odd protections. So
926 * we don't check the return value
932 * Some binaries have overlapping elf segments and then
933 * we have to forcefully map over an existing mapping
934 * e.g. over this newly established brk mapping.
936 elf_fixed = MAP_FIXED;
939 if (elf_ppnt->p_flags & PF_R)
940 elf_prot |= PROT_READ;
941 if (elf_ppnt->p_flags & PF_W)
942 elf_prot |= PROT_WRITE;
943 if (elf_ppnt->p_flags & PF_X)
944 elf_prot |= PROT_EXEC;
946 elf_flags = MAP_PRIVATE | MAP_DENYWRITE | MAP_EXECUTABLE;
948 vaddr = elf_ppnt->p_vaddr;
950 * If we are loading ET_EXEC or we have already performed
951 * the ET_DYN load_addr calculations, proceed normally.
953 if (loc->elf_ex.e_type == ET_EXEC || load_addr_set) {
954 elf_flags |= elf_fixed;
955 } else if (loc->elf_ex.e_type == ET_DYN) {
957 * This logic is run once for the first LOAD Program
958 * Header for ET_DYN binaries to calculate the
959 * randomization (load_bias) for all the LOAD
960 * Program Headers, and to calculate the entire
961 * size of the ELF mapping (total_size). (Note that
962 * load_addr_set is set to true later once the
963 * initial mapping is performed.)
965 * There are effectively two types of ET_DYN
966 * binaries: programs (i.e. PIE: ET_DYN with INTERP)
967 * and loaders (ET_DYN without INTERP, since they
968 * _are_ the ELF interpreter). The loaders must
969 * be loaded away from programs since the program
970 * may otherwise collide with the loader (especially
971 * for ET_EXEC which does not have a randomized
972 * position). For example to handle invocations of
973 * "./ld.so someprog" to test out a new version of
974 * the loader, the subsequent program that the
975 * loader loads must avoid the loader itself, so
976 * they cannot share the same load range. Sufficient
977 * room for the brk must be allocated with the
978 * loader as well, since brk must be available with
981 * Therefore, programs are loaded offset from
982 * ELF_ET_DYN_BASE and loaders are loaded into the
983 * independently randomized mmap region (0 load_bias
984 * without MAP_FIXED).
986 if (elf_interpreter) {
987 load_bias = ELF_ET_DYN_BASE;
988 if (current->flags & PF_RANDOMIZE)
989 load_bias += arch_mmap_rnd();
990 elf_flags |= elf_fixed;
995 * Since load_bias is used for all subsequent loading
996 * calculations, we must lower it by the first vaddr
997 * so that the remaining calculations based on the
998 * ELF vaddrs will be correctly offset. The result
999 * is then page aligned.
1001 load_bias = ELF_PAGESTART(load_bias - vaddr);
1003 total_size = total_mapping_size(elf_phdata,
1004 loc->elf_ex.e_phnum);
1007 goto out_free_dentry;
1011 error = elf_map(bprm->file, load_bias + vaddr, elf_ppnt,
1012 elf_prot, elf_flags, total_size);
1013 if (BAD_ADDR(error)) {
1014 retval = IS_ERR((void *)error) ?
1015 PTR_ERR((void*)error) : -EINVAL;
1016 goto out_free_dentry;
1019 if (!load_addr_set) {
1021 load_addr = (elf_ppnt->p_vaddr - elf_ppnt->p_offset);
1022 if (loc->elf_ex.e_type == ET_DYN) {
1023 load_bias += error -
1024 ELF_PAGESTART(load_bias + vaddr);
1025 load_addr += load_bias;
1026 reloc_func_desc = load_bias;
1029 k = elf_ppnt->p_vaddr;
1036 * Check to see if the section's size will overflow the
1037 * allowed task size. Note that p_filesz must always be
1038 * <= p_memsz so it is only necessary to check p_memsz.
1040 if (BAD_ADDR(k) || elf_ppnt->p_filesz > elf_ppnt->p_memsz ||
1041 elf_ppnt->p_memsz > TASK_SIZE ||
1042 TASK_SIZE - elf_ppnt->p_memsz < k) {
1043 /* set_brk can never work. Avoid overflows. */
1045 goto out_free_dentry;
1048 k = elf_ppnt->p_vaddr + elf_ppnt->p_filesz;
1052 if ((elf_ppnt->p_flags & PF_X) && end_code < k)
1056 k = elf_ppnt->p_vaddr + elf_ppnt->p_memsz;
1058 bss_prot = elf_prot;
1063 loc->elf_ex.e_entry += load_bias;
1064 elf_bss += load_bias;
1065 elf_brk += load_bias;
1066 start_code += load_bias;
1067 end_code += load_bias;
1068 start_data += load_bias;
1069 end_data += load_bias;
1071 /* Calling set_brk effectively mmaps the pages that we need
1072 * for the bss and break sections. We must do this before
1073 * mapping in the interpreter, to make sure it doesn't wind
1074 * up getting placed where the bss needs to go.
1076 retval = set_brk(elf_bss, elf_brk, bss_prot);
1078 goto out_free_dentry;
1079 if (likely(elf_bss != elf_brk) && unlikely(padzero(elf_bss))) {
1080 retval = -EFAULT; /* Nobody gets to see this, but.. */
1081 goto out_free_dentry;
1084 if (elf_interpreter) {
1085 unsigned long interp_map_addr = 0;
1087 elf_entry = load_elf_interp(&loc->interp_elf_ex,
1090 load_bias, interp_elf_phdata);
1091 if (!IS_ERR((void *)elf_entry)) {
1093 * load_elf_interp() returns relocation
1096 interp_load_addr = elf_entry;
1097 elf_entry += loc->interp_elf_ex.e_entry;
1099 if (BAD_ADDR(elf_entry)) {
1100 retval = IS_ERR((void *)elf_entry) ?
1101 (int)elf_entry : -EINVAL;
1102 goto out_free_dentry;
1104 reloc_func_desc = interp_load_addr;
1106 allow_write_access(interpreter);
1108 kfree(elf_interpreter);
1110 elf_entry = loc->elf_ex.e_entry;
1111 if (BAD_ADDR(elf_entry)) {
1113 goto out_free_dentry;
1117 kfree(interp_elf_phdata);
1120 set_binfmt(&elf_format);
1122 #ifdef ARCH_HAS_SETUP_ADDITIONAL_PAGES
1123 retval = arch_setup_additional_pages(bprm, !!elf_interpreter);
1126 #endif /* ARCH_HAS_SETUP_ADDITIONAL_PAGES */
1128 retval = create_elf_tables(bprm, &loc->elf_ex,
1129 load_addr, interp_load_addr);
1132 /* N.B. passed_fileno might not be initialized? */
1133 current->mm->end_code = end_code;
1134 current->mm->start_code = start_code;
1135 current->mm->start_data = start_data;
1136 current->mm->end_data = end_data;
1137 current->mm->start_stack = bprm->p;
1139 if ((current->flags & PF_RANDOMIZE) && (randomize_va_space > 1)) {
1141 * For architectures with ELF randomization, when executing
1142 * a loader directly (i.e. no interpreter listed in ELF
1143 * headers), move the brk area out of the mmap region
1144 * (since it grows up, and may collide early with the stack
1145 * growing down), and into the unused ELF_ET_DYN_BASE region.
1147 if (IS_ENABLED(CONFIG_ARCH_HAS_ELF_RANDOMIZE) && !interpreter)
1148 current->mm->brk = current->mm->start_brk =
1151 current->mm->brk = current->mm->start_brk =
1152 arch_randomize_brk(current->mm);
1153 #ifdef compat_brk_randomized
1154 current->brk_randomized = 1;
1158 if (current->personality & MMAP_PAGE_ZERO) {
1159 /* Why this, you ask??? Well SVr4 maps page 0 as read-only,
1160 and some applications "depend" upon this behavior.
1161 Since we do not have the power to recompile these, we
1162 emulate the SVr4 behavior. Sigh. */
1163 error = vm_mmap(NULL, 0, PAGE_SIZE, PROT_READ | PROT_EXEC,
1164 MAP_FIXED | MAP_PRIVATE, 0);
1167 #ifdef ELF_PLAT_INIT
1169 * The ABI may specify that certain registers be set up in special
1170 * ways (on i386 %edx is the address of a DT_FINI function, for
1171 * example. In addition, it may also specify (eg, PowerPC64 ELF)
1172 * that the e_entry field is the address of the function descriptor
1173 * for the startup routine, rather than the address of the startup
1174 * routine itself. This macro performs whatever initialization to
1175 * the regs structure is required as well as any relocations to the
1176 * function descriptor entries when executing dynamically links apps.
1178 ELF_PLAT_INIT(regs, reloc_func_desc);
1181 finalize_exec(bprm);
1182 start_thread(regs, elf_entry, bprm->p);
1191 kfree(interp_elf_phdata);
1192 allow_write_access(interpreter);
1196 kfree(elf_interpreter);
1202 #ifdef CONFIG_USELIB
1203 /* This is really simpleminded and specialized - we are loading an
1204 a.out library that is given an ELF header. */
1205 static int load_elf_library(struct file *file)
1207 struct elf_phdr *elf_phdata;
1208 struct elf_phdr *eppnt;
1209 unsigned long elf_bss, bss, len;
1210 int retval, error, i, j;
1211 struct elfhdr elf_ex;
1215 retval = kernel_read(file, &elf_ex, sizeof(elf_ex), &pos);
1216 if (retval != sizeof(elf_ex))
1219 if (memcmp(elf_ex.e_ident, ELFMAG, SELFMAG) != 0)
1222 /* First of all, some simple consistency checks */
1223 if (elf_ex.e_type != ET_EXEC || elf_ex.e_phnum > 2 ||
1224 !elf_check_arch(&elf_ex) || !file->f_op->mmap)
1226 if (elf_check_fdpic(&elf_ex))
1229 /* Now read in all of the header information */
1231 j = sizeof(struct elf_phdr) * elf_ex.e_phnum;
1232 /* j < ELF_MIN_ALIGN because elf_ex.e_phnum <= 2 */
1235 elf_phdata = kmalloc(j, GFP_KERNEL);
1241 pos = elf_ex.e_phoff;
1242 retval = kernel_read(file, eppnt, j, &pos);
1246 for (j = 0, i = 0; i<elf_ex.e_phnum; i++)
1247 if ((eppnt + i)->p_type == PT_LOAD)
1252 while (eppnt->p_type != PT_LOAD)
1255 /* Now use mmap to map the library into memory. */
1256 error = vm_mmap(file,
1257 ELF_PAGESTART(eppnt->p_vaddr),
1259 ELF_PAGEOFFSET(eppnt->p_vaddr)),
1260 PROT_READ | PROT_WRITE | PROT_EXEC,
1261 MAP_FIXED_NOREPLACE | MAP_PRIVATE | MAP_DENYWRITE,
1263 ELF_PAGEOFFSET(eppnt->p_vaddr)));
1264 if (error != ELF_PAGESTART(eppnt->p_vaddr))
1267 elf_bss = eppnt->p_vaddr + eppnt->p_filesz;
1268 if (padzero(elf_bss)) {
1273 len = ELF_PAGEALIGN(eppnt->p_filesz + eppnt->p_vaddr);
1274 bss = ELF_PAGEALIGN(eppnt->p_memsz + eppnt->p_vaddr);
1276 error = vm_brk(len, bss - len);
1287 #endif /* #ifdef CONFIG_USELIB */
1289 #ifdef CONFIG_ELF_CORE
1293 * Modelled on fs/exec.c:aout_core_dump()
1294 * Jeremy Fitzhardinge <jeremy@sw.oz.au>
1298 * The purpose of always_dump_vma() is to make sure that special kernel mappings
1299 * that are useful for post-mortem analysis are included in every core dump.
1300 * In that way we ensure that the core dump is fully interpretable later
1301 * without matching up the same kernel and hardware config to see what PC values
1302 * meant. These special mappings include - vDSO, vsyscall, and other
1303 * architecture specific mappings
1305 static bool always_dump_vma(struct vm_area_struct *vma)
1307 /* Any vsyscall mappings? */
1308 if (vma == get_gate_vma(vma->vm_mm))
1312 * Assume that all vmas with a .name op should always be dumped.
1313 * If this changes, a new vm_ops field can easily be added.
1315 if (vma->vm_ops && vma->vm_ops->name && vma->vm_ops->name(vma))
1319 * arch_vma_name() returns non-NULL for special architecture mappings,
1320 * such as vDSO sections.
1322 if (arch_vma_name(vma))
1329 * Decide what to dump of a segment, part, all or none.
1331 static unsigned long vma_dump_size(struct vm_area_struct *vma,
1332 unsigned long mm_flags)
1334 #define FILTER(type) (mm_flags & (1UL << MMF_DUMP_##type))
1336 /* always dump the vdso and vsyscall sections */
1337 if (always_dump_vma(vma))
1340 if (vma->vm_flags & VM_DONTDUMP)
1343 /* support for DAX */
1344 if (vma_is_dax(vma)) {
1345 if ((vma->vm_flags & VM_SHARED) && FILTER(DAX_SHARED))
1347 if (!(vma->vm_flags & VM_SHARED) && FILTER(DAX_PRIVATE))
1352 /* Hugetlb memory check */
1353 if (vma->vm_flags & VM_HUGETLB) {
1354 if ((vma->vm_flags & VM_SHARED) && FILTER(HUGETLB_SHARED))
1356 if (!(vma->vm_flags & VM_SHARED) && FILTER(HUGETLB_PRIVATE))
1361 /* Do not dump I/O mapped devices or special mappings */
1362 if (vma->vm_flags & VM_IO)
1365 /* By default, dump shared memory if mapped from an anonymous file. */
1366 if (vma->vm_flags & VM_SHARED) {
1367 if (file_inode(vma->vm_file)->i_nlink == 0 ?
1368 FILTER(ANON_SHARED) : FILTER(MAPPED_SHARED))
1373 /* Dump segments that have been written to. */
1374 if (vma->anon_vma && FILTER(ANON_PRIVATE))
1376 if (vma->vm_file == NULL)
1379 if (FILTER(MAPPED_PRIVATE))
1383 * If this looks like the beginning of a DSO or executable mapping,
1384 * check for an ELF header. If we find one, dump the first page to
1385 * aid in determining what was mapped here.
1387 if (FILTER(ELF_HEADERS) &&
1388 vma->vm_pgoff == 0 && (vma->vm_flags & VM_READ)) {
1389 u32 __user *header = (u32 __user *) vma->vm_start;
1391 mm_segment_t fs = get_fs();
1393 * Doing it this way gets the constant folded by GCC.
1397 char elfmag[SELFMAG];
1399 BUILD_BUG_ON(SELFMAG != sizeof word);
1400 magic.elfmag[EI_MAG0] = ELFMAG0;
1401 magic.elfmag[EI_MAG1] = ELFMAG1;
1402 magic.elfmag[EI_MAG2] = ELFMAG2;
1403 magic.elfmag[EI_MAG3] = ELFMAG3;
1405 * Switch to the user "segment" for get_user(),
1406 * then put back what elf_core_dump() had in place.
1409 if (unlikely(get_user(word, header)))
1412 if (word == magic.cmp)
1421 return vma->vm_end - vma->vm_start;
1424 /* An ELF note in memory */
1429 unsigned int datasz;
1433 static int notesize(struct memelfnote *en)
1437 sz = sizeof(struct elf_note);
1438 sz += roundup(strlen(en->name) + 1, 4);
1439 sz += roundup(en->datasz, 4);
1444 static int writenote(struct memelfnote *men, struct coredump_params *cprm)
1447 en.n_namesz = strlen(men->name) + 1;
1448 en.n_descsz = men->datasz;
1449 en.n_type = men->type;
1451 return dump_emit(cprm, &en, sizeof(en)) &&
1452 dump_emit(cprm, men->name, en.n_namesz) && dump_align(cprm, 4) &&
1453 dump_emit(cprm, men->data, men->datasz) && dump_align(cprm, 4);
1456 static void fill_elf_header(struct elfhdr *elf, int segs,
1457 u16 machine, u32 flags)
1459 memset(elf, 0, sizeof(*elf));
1461 memcpy(elf->e_ident, ELFMAG, SELFMAG);
1462 elf->e_ident[EI_CLASS] = ELF_CLASS;
1463 elf->e_ident[EI_DATA] = ELF_DATA;
1464 elf->e_ident[EI_VERSION] = EV_CURRENT;
1465 elf->e_ident[EI_OSABI] = ELF_OSABI;
1467 elf->e_type = ET_CORE;
1468 elf->e_machine = machine;
1469 elf->e_version = EV_CURRENT;
1470 elf->e_phoff = sizeof(struct elfhdr);
1471 elf->e_flags = flags;
1472 elf->e_ehsize = sizeof(struct elfhdr);
1473 elf->e_phentsize = sizeof(struct elf_phdr);
1474 elf->e_phnum = segs;
1479 static void fill_elf_note_phdr(struct elf_phdr *phdr, int sz, loff_t offset)
1481 phdr->p_type = PT_NOTE;
1482 phdr->p_offset = offset;
1485 phdr->p_filesz = sz;
1492 static void fill_note(struct memelfnote *note, const char *name, int type,
1493 unsigned int sz, void *data)
1503 * fill up all the fields in prstatus from the given task struct, except
1504 * registers which need to be filled up separately.
1506 static void fill_prstatus(struct elf_prstatus *prstatus,
1507 struct task_struct *p, long signr)
1509 prstatus->pr_info.si_signo = prstatus->pr_cursig = signr;
1510 prstatus->pr_sigpend = p->pending.signal.sig[0];
1511 prstatus->pr_sighold = p->blocked.sig[0];
1513 prstatus->pr_ppid = task_pid_vnr(rcu_dereference(p->real_parent));
1515 prstatus->pr_pid = task_pid_vnr(p);
1516 prstatus->pr_pgrp = task_pgrp_vnr(p);
1517 prstatus->pr_sid = task_session_vnr(p);
1518 if (thread_group_leader(p)) {
1519 struct task_cputime cputime;
1522 * This is the record for the group leader. It shows the
1523 * group-wide total, not its individual thread total.
1525 thread_group_cputime(p, &cputime);
1526 prstatus->pr_utime = ns_to_timeval(cputime.utime);
1527 prstatus->pr_stime = ns_to_timeval(cputime.stime);
1531 task_cputime(p, &utime, &stime);
1532 prstatus->pr_utime = ns_to_timeval(utime);
1533 prstatus->pr_stime = ns_to_timeval(stime);
1536 prstatus->pr_cutime = ns_to_timeval(p->signal->cutime);
1537 prstatus->pr_cstime = ns_to_timeval(p->signal->cstime);
1540 static int fill_psinfo(struct elf_prpsinfo *psinfo, struct task_struct *p,
1541 struct mm_struct *mm)
1543 const struct cred *cred;
1544 unsigned int i, len;
1546 /* first copy the parameters from user space */
1547 memset(psinfo, 0, sizeof(struct elf_prpsinfo));
1549 len = mm->arg_end - mm->arg_start;
1550 if (len >= ELF_PRARGSZ)
1551 len = ELF_PRARGSZ-1;
1552 if (copy_from_user(&psinfo->pr_psargs,
1553 (const char __user *)mm->arg_start, len))
1555 for(i = 0; i < len; i++)
1556 if (psinfo->pr_psargs[i] == 0)
1557 psinfo->pr_psargs[i] = ' ';
1558 psinfo->pr_psargs[len] = 0;
1561 psinfo->pr_ppid = task_pid_vnr(rcu_dereference(p->real_parent));
1563 psinfo->pr_pid = task_pid_vnr(p);
1564 psinfo->pr_pgrp = task_pgrp_vnr(p);
1565 psinfo->pr_sid = task_session_vnr(p);
1567 i = p->state ? ffz(~p->state) + 1 : 0;
1568 psinfo->pr_state = i;
1569 psinfo->pr_sname = (i > 5) ? '.' : "RSDTZW"[i];
1570 psinfo->pr_zomb = psinfo->pr_sname == 'Z';
1571 psinfo->pr_nice = task_nice(p);
1572 psinfo->pr_flag = p->flags;
1574 cred = __task_cred(p);
1575 SET_UID(psinfo->pr_uid, from_kuid_munged(cred->user_ns, cred->uid));
1576 SET_GID(psinfo->pr_gid, from_kgid_munged(cred->user_ns, cred->gid));
1578 strncpy(psinfo->pr_fname, p->comm, sizeof(psinfo->pr_fname));
1583 static void fill_auxv_note(struct memelfnote *note, struct mm_struct *mm)
1585 elf_addr_t *auxv = (elf_addr_t *) mm->saved_auxv;
1589 while (auxv[i - 2] != AT_NULL);
1590 fill_note(note, "CORE", NT_AUXV, i * sizeof(elf_addr_t), auxv);
1593 static void fill_siginfo_note(struct memelfnote *note, user_siginfo_t *csigdata,
1594 const siginfo_t *siginfo)
1596 mm_segment_t old_fs = get_fs();
1598 copy_siginfo_to_user((user_siginfo_t __user *) csigdata, siginfo);
1600 fill_note(note, "CORE", NT_SIGINFO, sizeof(*csigdata), csigdata);
1603 #define MAX_FILE_NOTE_SIZE (4*1024*1024)
1605 * Format of NT_FILE note:
1607 * long count -- how many files are mapped
1608 * long page_size -- units for file_ofs
1609 * array of [COUNT] elements of
1613 * followed by COUNT filenames in ASCII: "FILE1" NUL "FILE2" NUL...
1615 static int fill_files_note(struct memelfnote *note)
1617 struct vm_area_struct *vma;
1618 unsigned count, size, names_ofs, remaining, n;
1620 user_long_t *start_end_ofs;
1621 char *name_base, *name_curpos;
1623 /* *Estimated* file count and total data size needed */
1624 count = current->mm->map_count;
1625 if (count > UINT_MAX / 64)
1629 names_ofs = (2 + 3 * count) * sizeof(data[0]);
1631 if (size >= MAX_FILE_NOTE_SIZE) /* paranoia check */
1633 size = round_up(size, PAGE_SIZE);
1634 data = kvmalloc(size, GFP_KERNEL);
1635 if (ZERO_OR_NULL_PTR(data))
1638 start_end_ofs = data + 2;
1639 name_base = name_curpos = ((char *)data) + names_ofs;
1640 remaining = size - names_ofs;
1642 for (vma = current->mm->mmap; vma != NULL; vma = vma->vm_next) {
1644 const char *filename;
1646 file = vma->vm_file;
1649 filename = file_path(file, name_curpos, remaining);
1650 if (IS_ERR(filename)) {
1651 if (PTR_ERR(filename) == -ENAMETOOLONG) {
1653 size = size * 5 / 4;
1659 /* file_path() fills at the end, move name down */
1660 /* n = strlen(filename) + 1: */
1661 n = (name_curpos + remaining) - filename;
1662 remaining = filename - name_curpos;
1663 memmove(name_curpos, filename, n);
1666 *start_end_ofs++ = vma->vm_start;
1667 *start_end_ofs++ = vma->vm_end;
1668 *start_end_ofs++ = vma->vm_pgoff;
1672 /* Now we know exact count of files, can store it */
1674 data[1] = PAGE_SIZE;
1676 * Count usually is less than current->mm->map_count,
1677 * we need to move filenames down.
1679 n = current->mm->map_count - count;
1681 unsigned shift_bytes = n * 3 * sizeof(data[0]);
1682 memmove(name_base - shift_bytes, name_base,
1683 name_curpos - name_base);
1684 name_curpos -= shift_bytes;
1687 size = name_curpos - (char *)data;
1688 fill_note(note, "CORE", NT_FILE, size, data);
1692 #ifdef CORE_DUMP_USE_REGSET
1693 #include <linux/regset.h>
1695 struct elf_thread_core_info {
1696 struct elf_thread_core_info *next;
1697 struct task_struct *task;
1698 struct elf_prstatus prstatus;
1699 struct memelfnote notes[0];
1702 struct elf_note_info {
1703 struct elf_thread_core_info *thread;
1704 struct memelfnote psinfo;
1705 struct memelfnote signote;
1706 struct memelfnote auxv;
1707 struct memelfnote files;
1708 user_siginfo_t csigdata;
1714 * When a regset has a writeback hook, we call it on each thread before
1715 * dumping user memory. On register window machines, this makes sure the
1716 * user memory backing the register data is up to date before we read it.
1718 static void do_thread_regset_writeback(struct task_struct *task,
1719 const struct user_regset *regset)
1721 if (regset->writeback)
1722 regset->writeback(task, regset, 1);
1725 #ifndef PRSTATUS_SIZE
1726 #define PRSTATUS_SIZE(S, R) sizeof(S)
1729 #ifndef SET_PR_FPVALID
1730 #define SET_PR_FPVALID(S, V, R) ((S)->pr_fpvalid = (V))
1733 static int fill_thread_core_info(struct elf_thread_core_info *t,
1734 const struct user_regset_view *view,
1735 long signr, size_t *total)
1738 unsigned int regset0_size = regset_size(t->task, &view->regsets[0]);
1741 * NT_PRSTATUS is the one special case, because the regset data
1742 * goes into the pr_reg field inside the note contents, rather
1743 * than being the whole note contents. We fill the reset in here.
1744 * We assume that regset 0 is NT_PRSTATUS.
1746 fill_prstatus(&t->prstatus, t->task, signr);
1747 (void) view->regsets[0].get(t->task, &view->regsets[0], 0, regset0_size,
1748 &t->prstatus.pr_reg, NULL);
1750 fill_note(&t->notes[0], "CORE", NT_PRSTATUS,
1751 PRSTATUS_SIZE(t->prstatus, regset0_size), &t->prstatus);
1752 *total += notesize(&t->notes[0]);
1754 do_thread_regset_writeback(t->task, &view->regsets[0]);
1757 * Each other regset might generate a note too. For each regset
1758 * that has no core_note_type or is inactive, we leave t->notes[i]
1759 * all zero and we'll know to skip writing it later.
1761 for (i = 1; i < view->n; ++i) {
1762 const struct user_regset *regset = &view->regsets[i];
1763 do_thread_regset_writeback(t->task, regset);
1764 if (regset->core_note_type && regset->get &&
1765 (!regset->active || regset->active(t->task, regset) > 0)) {
1767 size_t size = regset_size(t->task, regset);
1768 void *data = kmalloc(size, GFP_KERNEL);
1769 if (unlikely(!data))
1771 ret = regset->get(t->task, regset,
1772 0, size, data, NULL);
1776 if (regset->core_note_type != NT_PRFPREG)
1777 fill_note(&t->notes[i], "LINUX",
1778 regset->core_note_type,
1781 SET_PR_FPVALID(&t->prstatus,
1783 fill_note(&t->notes[i], "CORE",
1784 NT_PRFPREG, size, data);
1786 *total += notesize(&t->notes[i]);
1794 static int fill_note_info(struct elfhdr *elf, int phdrs,
1795 struct elf_note_info *info,
1796 const siginfo_t *siginfo, struct pt_regs *regs)
1798 struct task_struct *dump_task = current;
1799 const struct user_regset_view *view = task_user_regset_view(dump_task);
1800 struct elf_thread_core_info *t;
1801 struct elf_prpsinfo *psinfo;
1802 struct core_thread *ct;
1806 info->thread = NULL;
1808 psinfo = kmalloc(sizeof(*psinfo), GFP_KERNEL);
1809 if (psinfo == NULL) {
1810 info->psinfo.data = NULL; /* So we don't free this wrongly */
1814 fill_note(&info->psinfo, "CORE", NT_PRPSINFO, sizeof(*psinfo), psinfo);
1817 * Figure out how many notes we're going to need for each thread.
1819 info->thread_notes = 0;
1820 for (i = 0; i < view->n; ++i)
1821 if (view->regsets[i].core_note_type != 0)
1822 ++info->thread_notes;
1825 * Sanity check. We rely on regset 0 being in NT_PRSTATUS,
1826 * since it is our one special case.
1828 if (unlikely(info->thread_notes == 0) ||
1829 unlikely(view->regsets[0].core_note_type != NT_PRSTATUS)) {
1835 * Initialize the ELF file header.
1837 fill_elf_header(elf, phdrs,
1838 view->e_machine, view->e_flags);
1841 * Allocate a structure for each thread.
1843 for (ct = &dump_task->mm->core_state->dumper; ct; ct = ct->next) {
1844 t = kzalloc(offsetof(struct elf_thread_core_info,
1845 notes[info->thread_notes]),
1851 if (ct->task == dump_task || !info->thread) {
1852 t->next = info->thread;
1856 * Make sure to keep the original task at
1857 * the head of the list.
1859 t->next = info->thread->next;
1860 info->thread->next = t;
1865 * Now fill in each thread's information.
1867 for (t = info->thread; t != NULL; t = t->next)
1868 if (!fill_thread_core_info(t, view, siginfo->si_signo, &info->size))
1872 * Fill in the two process-wide notes.
1874 fill_psinfo(psinfo, dump_task->group_leader, dump_task->mm);
1875 info->size += notesize(&info->psinfo);
1877 fill_siginfo_note(&info->signote, &info->csigdata, siginfo);
1878 info->size += notesize(&info->signote);
1880 fill_auxv_note(&info->auxv, current->mm);
1881 info->size += notesize(&info->auxv);
1883 if (fill_files_note(&info->files) == 0)
1884 info->size += notesize(&info->files);
1889 static size_t get_note_info_size(struct elf_note_info *info)
1895 * Write all the notes for each thread. When writing the first thread, the
1896 * process-wide notes are interleaved after the first thread-specific note.
1898 static int write_note_info(struct elf_note_info *info,
1899 struct coredump_params *cprm)
1902 struct elf_thread_core_info *t = info->thread;
1907 if (!writenote(&t->notes[0], cprm))
1910 if (first && !writenote(&info->psinfo, cprm))
1912 if (first && !writenote(&info->signote, cprm))
1914 if (first && !writenote(&info->auxv, cprm))
1916 if (first && info->files.data &&
1917 !writenote(&info->files, cprm))
1920 for (i = 1; i < info->thread_notes; ++i)
1921 if (t->notes[i].data &&
1922 !writenote(&t->notes[i], cprm))
1932 static void free_note_info(struct elf_note_info *info)
1934 struct elf_thread_core_info *threads = info->thread;
1937 struct elf_thread_core_info *t = threads;
1939 WARN_ON(t->notes[0].data && t->notes[0].data != &t->prstatus);
1940 for (i = 1; i < info->thread_notes; ++i)
1941 kfree(t->notes[i].data);
1944 kfree(info->psinfo.data);
1945 kvfree(info->files.data);
1950 /* Here is the structure in which status of each thread is captured. */
1951 struct elf_thread_status
1953 struct list_head list;
1954 struct elf_prstatus prstatus; /* NT_PRSTATUS */
1955 elf_fpregset_t fpu; /* NT_PRFPREG */
1956 struct task_struct *thread;
1957 #ifdef ELF_CORE_COPY_XFPREGS
1958 elf_fpxregset_t xfpu; /* ELF_CORE_XFPREG_TYPE */
1960 struct memelfnote notes[3];
1965 * In order to add the specific thread information for the elf file format,
1966 * we need to keep a linked list of every threads pr_status and then create
1967 * a single section for them in the final core file.
1969 static int elf_dump_thread_status(long signr, struct elf_thread_status *t)
1972 struct task_struct *p = t->thread;
1975 fill_prstatus(&t->prstatus, p, signr);
1976 elf_core_copy_task_regs(p, &t->prstatus.pr_reg);
1978 fill_note(&t->notes[0], "CORE", NT_PRSTATUS, sizeof(t->prstatus),
1981 sz += notesize(&t->notes[0]);
1983 if ((t->prstatus.pr_fpvalid = elf_core_copy_task_fpregs(p, NULL,
1985 fill_note(&t->notes[1], "CORE", NT_PRFPREG, sizeof(t->fpu),
1988 sz += notesize(&t->notes[1]);
1991 #ifdef ELF_CORE_COPY_XFPREGS
1992 if (elf_core_copy_task_xfpregs(p, &t->xfpu)) {
1993 fill_note(&t->notes[2], "LINUX", ELF_CORE_XFPREG_TYPE,
1994 sizeof(t->xfpu), &t->xfpu);
1996 sz += notesize(&t->notes[2]);
2002 struct elf_note_info {
2003 struct memelfnote *notes;
2004 struct memelfnote *notes_files;
2005 struct elf_prstatus *prstatus; /* NT_PRSTATUS */
2006 struct elf_prpsinfo *psinfo; /* NT_PRPSINFO */
2007 struct list_head thread_list;
2008 elf_fpregset_t *fpu;
2009 #ifdef ELF_CORE_COPY_XFPREGS
2010 elf_fpxregset_t *xfpu;
2012 user_siginfo_t csigdata;
2013 int thread_status_size;
2017 static int elf_note_info_init(struct elf_note_info *info)
2019 memset(info, 0, sizeof(*info));
2020 INIT_LIST_HEAD(&info->thread_list);
2022 /* Allocate space for ELF notes */
2023 info->notes = kmalloc_array(8, sizeof(struct memelfnote), GFP_KERNEL);
2026 info->psinfo = kmalloc(sizeof(*info->psinfo), GFP_KERNEL);
2029 info->prstatus = kmalloc(sizeof(*info->prstatus), GFP_KERNEL);
2030 if (!info->prstatus)
2032 info->fpu = kmalloc(sizeof(*info->fpu), GFP_KERNEL);
2035 #ifdef ELF_CORE_COPY_XFPREGS
2036 info->xfpu = kmalloc(sizeof(*info->xfpu), GFP_KERNEL);
2043 static int fill_note_info(struct elfhdr *elf, int phdrs,
2044 struct elf_note_info *info,
2045 const siginfo_t *siginfo, struct pt_regs *regs)
2047 struct list_head *t;
2048 struct core_thread *ct;
2049 struct elf_thread_status *ets;
2051 if (!elf_note_info_init(info))
2054 for (ct = current->mm->core_state->dumper.next;
2055 ct; ct = ct->next) {
2056 ets = kzalloc(sizeof(*ets), GFP_KERNEL);
2060 ets->thread = ct->task;
2061 list_add(&ets->list, &info->thread_list);
2064 list_for_each(t, &info->thread_list) {
2067 ets = list_entry(t, struct elf_thread_status, list);
2068 sz = elf_dump_thread_status(siginfo->si_signo, ets);
2069 info->thread_status_size += sz;
2071 /* now collect the dump for the current */
2072 memset(info->prstatus, 0, sizeof(*info->prstatus));
2073 fill_prstatus(info->prstatus, current, siginfo->si_signo);
2074 elf_core_copy_regs(&info->prstatus->pr_reg, regs);
2077 fill_elf_header(elf, phdrs, ELF_ARCH, ELF_CORE_EFLAGS);
2080 * Set up the notes in similar form to SVR4 core dumps made
2081 * with info from their /proc.
2084 fill_note(info->notes + 0, "CORE", NT_PRSTATUS,
2085 sizeof(*info->prstatus), info->prstatus);
2086 fill_psinfo(info->psinfo, current->group_leader, current->mm);
2087 fill_note(info->notes + 1, "CORE", NT_PRPSINFO,
2088 sizeof(*info->psinfo), info->psinfo);
2090 fill_siginfo_note(info->notes + 2, &info->csigdata, siginfo);
2091 fill_auxv_note(info->notes + 3, current->mm);
2094 if (fill_files_note(info->notes + info->numnote) == 0) {
2095 info->notes_files = info->notes + info->numnote;
2099 /* Try to dump the FPU. */
2100 info->prstatus->pr_fpvalid = elf_core_copy_task_fpregs(current, regs,
2102 if (info->prstatus->pr_fpvalid)
2103 fill_note(info->notes + info->numnote++,
2104 "CORE", NT_PRFPREG, sizeof(*info->fpu), info->fpu);
2105 #ifdef ELF_CORE_COPY_XFPREGS
2106 if (elf_core_copy_task_xfpregs(current, info->xfpu))
2107 fill_note(info->notes + info->numnote++,
2108 "LINUX", ELF_CORE_XFPREG_TYPE,
2109 sizeof(*info->xfpu), info->xfpu);
2115 static size_t get_note_info_size(struct elf_note_info *info)
2120 for (i = 0; i < info->numnote; i++)
2121 sz += notesize(info->notes + i);
2123 sz += info->thread_status_size;
2128 static int write_note_info(struct elf_note_info *info,
2129 struct coredump_params *cprm)
2132 struct list_head *t;
2134 for (i = 0; i < info->numnote; i++)
2135 if (!writenote(info->notes + i, cprm))
2138 /* write out the thread status notes section */
2139 list_for_each(t, &info->thread_list) {
2140 struct elf_thread_status *tmp =
2141 list_entry(t, struct elf_thread_status, list);
2143 for (i = 0; i < tmp->num_notes; i++)
2144 if (!writenote(&tmp->notes[i], cprm))
2151 static void free_note_info(struct elf_note_info *info)
2153 while (!list_empty(&info->thread_list)) {
2154 struct list_head *tmp = info->thread_list.next;
2156 kfree(list_entry(tmp, struct elf_thread_status, list));
2159 /* Free data possibly allocated by fill_files_note(): */
2160 if (info->notes_files)
2161 kvfree(info->notes_files->data);
2163 kfree(info->prstatus);
2164 kfree(info->psinfo);
2167 #ifdef ELF_CORE_COPY_XFPREGS
2174 static struct vm_area_struct *first_vma(struct task_struct *tsk,
2175 struct vm_area_struct *gate_vma)
2177 struct vm_area_struct *ret = tsk->mm->mmap;
2184 * Helper function for iterating across a vma list. It ensures that the caller
2185 * will visit `gate_vma' prior to terminating the search.
2187 static struct vm_area_struct *next_vma(struct vm_area_struct *this_vma,
2188 struct vm_area_struct *gate_vma)
2190 struct vm_area_struct *ret;
2192 ret = this_vma->vm_next;
2195 if (this_vma == gate_vma)
2200 static void fill_extnum_info(struct elfhdr *elf, struct elf_shdr *shdr4extnum,
2201 elf_addr_t e_shoff, int segs)
2203 elf->e_shoff = e_shoff;
2204 elf->e_shentsize = sizeof(*shdr4extnum);
2206 elf->e_shstrndx = SHN_UNDEF;
2208 memset(shdr4extnum, 0, sizeof(*shdr4extnum));
2210 shdr4extnum->sh_type = SHT_NULL;
2211 shdr4extnum->sh_size = elf->e_shnum;
2212 shdr4extnum->sh_link = elf->e_shstrndx;
2213 shdr4extnum->sh_info = segs;
2219 * This is a two-pass process; first we find the offsets of the bits,
2220 * and then they are actually written out. If we run out of core limit
2223 static int elf_core_dump(struct coredump_params *cprm)
2228 size_t vma_data_size = 0;
2229 struct vm_area_struct *vma, *gate_vma;
2230 struct elfhdr *elf = NULL;
2231 loff_t offset = 0, dataoff;
2232 struct elf_note_info info = { };
2233 struct elf_phdr *phdr4note = NULL;
2234 struct elf_shdr *shdr4extnum = NULL;
2237 elf_addr_t *vma_filesz = NULL;
2240 * We no longer stop all VM operations.
2242 * This is because those proceses that could possibly change map_count
2243 * or the mmap / vma pages are now blocked in do_exit on current
2244 * finishing this core dump.
2246 * Only ptrace can touch these memory addresses, but it doesn't change
2247 * the map_count or the pages allocated. So no possibility of crashing
2248 * exists while dumping the mm->vm_next areas to the core file.
2251 /* alloc memory for large data structures: too large to be on stack */
2252 elf = kmalloc(sizeof(*elf), GFP_KERNEL);
2256 * The number of segs are recored into ELF header as 16bit value.
2257 * Please check DEFAULT_MAX_MAP_COUNT definition when you modify here.
2259 segs = current->mm->map_count;
2260 segs += elf_core_extra_phdrs();
2262 gate_vma = get_gate_vma(current->mm);
2263 if (gate_vma != NULL)
2266 /* for notes section */
2269 /* If segs > PN_XNUM(0xffff), then e_phnum overflows. To avoid
2270 * this, kernel supports extended numbering. Have a look at
2271 * include/linux/elf.h for further information. */
2272 e_phnum = segs > PN_XNUM ? PN_XNUM : segs;
2275 * Collect all the non-memory information about the process for the
2276 * notes. This also sets up the file header.
2278 if (!fill_note_info(elf, e_phnum, &info, cprm->siginfo, cprm->regs))
2286 offset += sizeof(*elf); /* Elf header */
2287 offset += segs * sizeof(struct elf_phdr); /* Program headers */
2289 /* Write notes phdr entry */
2291 size_t sz = get_note_info_size(&info);
2293 sz += elf_coredump_extra_notes_size();
2295 phdr4note = kmalloc(sizeof(*phdr4note), GFP_KERNEL);
2299 fill_elf_note_phdr(phdr4note, sz, offset);
2303 dataoff = offset = roundup(offset, ELF_EXEC_PAGESIZE);
2305 if (segs - 1 > ULONG_MAX / sizeof(*vma_filesz))
2307 vma_filesz = kvmalloc(array_size(sizeof(*vma_filesz), (segs - 1)),
2309 if (ZERO_OR_NULL_PTR(vma_filesz))
2312 for (i = 0, vma = first_vma(current, gate_vma); vma != NULL;
2313 vma = next_vma(vma, gate_vma)) {
2314 unsigned long dump_size;
2316 dump_size = vma_dump_size(vma, cprm->mm_flags);
2317 vma_filesz[i++] = dump_size;
2318 vma_data_size += dump_size;
2321 offset += vma_data_size;
2322 offset += elf_core_extra_data_size();
2325 if (e_phnum == PN_XNUM) {
2326 shdr4extnum = kmalloc(sizeof(*shdr4extnum), GFP_KERNEL);
2329 fill_extnum_info(elf, shdr4extnum, e_shoff, segs);
2334 if (!dump_emit(cprm, elf, sizeof(*elf)))
2337 if (!dump_emit(cprm, phdr4note, sizeof(*phdr4note)))
2340 /* Write program headers for segments dump */
2341 for (i = 0, vma = first_vma(current, gate_vma); vma != NULL;
2342 vma = next_vma(vma, gate_vma)) {
2343 struct elf_phdr phdr;
2345 phdr.p_type = PT_LOAD;
2346 phdr.p_offset = offset;
2347 phdr.p_vaddr = vma->vm_start;
2349 phdr.p_filesz = vma_filesz[i++];
2350 phdr.p_memsz = vma->vm_end - vma->vm_start;
2351 offset += phdr.p_filesz;
2352 phdr.p_flags = vma->vm_flags & VM_READ ? PF_R : 0;
2353 if (vma->vm_flags & VM_WRITE)
2354 phdr.p_flags |= PF_W;
2355 if (vma->vm_flags & VM_EXEC)
2356 phdr.p_flags |= PF_X;
2357 phdr.p_align = ELF_EXEC_PAGESIZE;
2359 if (!dump_emit(cprm, &phdr, sizeof(phdr)))
2363 if (!elf_core_write_extra_phdrs(cprm, offset))
2366 /* write out the notes section */
2367 if (!write_note_info(&info, cprm))
2370 if (elf_coredump_extra_notes_write(cprm))
2374 if (!dump_skip(cprm, dataoff - cprm->pos))
2377 for (i = 0, vma = first_vma(current, gate_vma); vma != NULL;
2378 vma = next_vma(vma, gate_vma)) {
2382 end = vma->vm_start + vma_filesz[i++];
2384 for (addr = vma->vm_start; addr < end; addr += PAGE_SIZE) {
2388 page = get_dump_page(addr);
2390 void *kaddr = kmap(page);
2391 stop = !dump_emit(cprm, kaddr, PAGE_SIZE);
2395 stop = !dump_skip(cprm, PAGE_SIZE);
2400 dump_truncate(cprm);
2402 if (!elf_core_write_extra_data(cprm))
2405 if (e_phnum == PN_XNUM) {
2406 if (!dump_emit(cprm, shdr4extnum, sizeof(*shdr4extnum)))
2414 free_note_info(&info);
2423 #endif /* CONFIG_ELF_CORE */
2425 static int __init init_elf_binfmt(void)
2427 register_binfmt(&elf_format);
2431 static void __exit exit_elf_binfmt(void)
2433 /* Remove the COFF and ELF loaders. */
2434 unregister_binfmt(&elf_format);
2437 core_initcall(init_elf_binfmt);
2438 module_exit(exit_elf_binfmt);
2439 MODULE_LICENSE("GPL");