1 // SPDX-License-Identifier: GPL-2.0-only
3 * linux/fs/binfmt_elf.c
5 * These are the functions used to load ELF format executables as used
6 * on SVr4 machines. Information on the format may be found in the book
7 * "UNIX SYSTEM V RELEASE 4 Programmers Guide: Ansi C and Programming Support
10 * Copyright 1993, 1994: Eric Youngdale (ericy@cais.com).
13 #include <linux/module.h>
14 #include <linux/kernel.h>
17 #include <linux/mman.h>
18 #include <linux/errno.h>
19 #include <linux/signal.h>
20 #include <linux/binfmts.h>
21 #include <linux/string.h>
22 #include <linux/file.h>
23 #include <linux/slab.h>
24 #include <linux/personality.h>
25 #include <linux/elfcore.h>
26 #include <linux/init.h>
27 #include <linux/highuid.h>
28 #include <linux/compiler.h>
29 #include <linux/highmem.h>
30 #include <linux/hugetlb.h>
31 #include <linux/pagemap.h>
32 #include <linux/vmalloc.h>
33 #include <linux/security.h>
34 #include <linux/random.h>
35 #include <linux/elf.h>
36 #include <linux/elf-randomize.h>
37 #include <linux/utsname.h>
38 #include <linux/coredump.h>
39 #include <linux/sched.h>
40 #include <linux/sched/coredump.h>
41 #include <linux/sched/task_stack.h>
42 #include <linux/sched/cputime.h>
43 #include <linux/cred.h>
44 #include <linux/dax.h>
45 #include <linux/uaccess.h>
46 #include <asm/param.h>
50 #define user_long_t long
52 #ifndef user_siginfo_t
53 #define user_siginfo_t siginfo_t
56 /* That's for binfmt_elf_fdpic to deal with */
57 #ifndef elf_check_fdpic
58 #define elf_check_fdpic(ex) false
61 static int load_elf_binary(struct linux_binprm *bprm);
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) (unlikely((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, const struct elfhdr *exec,
166 unsigned long load_addr, unsigned long interp_load_addr,
167 unsigned long e_entry)
169 struct mm_struct *mm = current->mm;
170 unsigned long p = bprm->p;
171 int argc = bprm->argc;
172 int envc = bprm->envc;
173 elf_addr_t __user *sp;
174 elf_addr_t __user *u_platform;
175 elf_addr_t __user *u_base_platform;
176 elf_addr_t __user *u_rand_bytes;
177 const char *k_platform = ELF_PLATFORM;
178 const char *k_base_platform = ELF_BASE_PLATFORM;
179 unsigned char k_rand_bytes[16];
181 elf_addr_t *elf_info;
183 const struct cred *cred = current_cred();
184 struct vm_area_struct *vma;
187 * In some cases (e.g. Hyper-Threading), we want to avoid L1
188 * evictions by the processes running on the same package. One
189 * thing we can do is to shuffle the initial stack for them.
192 p = arch_align_stack(p);
195 * If this architecture has a platform capability string, copy it
196 * to userspace. In some cases (Sparc), this info is impossible
197 * for userspace to get any other way, in others (i386) it is
202 size_t len = strlen(k_platform) + 1;
204 u_platform = (elf_addr_t __user *)STACK_ALLOC(p, len);
205 if (__copy_to_user(u_platform, k_platform, len))
210 * If this architecture has a "base" platform capability
211 * string, copy it to userspace.
213 u_base_platform = NULL;
214 if (k_base_platform) {
215 size_t len = strlen(k_base_platform) + 1;
217 u_base_platform = (elf_addr_t __user *)STACK_ALLOC(p, len);
218 if (__copy_to_user(u_base_platform, k_base_platform, len))
223 * Generate 16 random bytes for userspace PRNG seeding.
225 get_random_bytes(k_rand_bytes, sizeof(k_rand_bytes));
226 u_rand_bytes = (elf_addr_t __user *)
227 STACK_ALLOC(p, sizeof(k_rand_bytes));
228 if (__copy_to_user(u_rand_bytes, k_rand_bytes, sizeof(k_rand_bytes)))
231 /* Create the ELF interpreter info */
232 elf_info = (elf_addr_t *)mm->saved_auxv;
233 /* update AT_VECTOR_SIZE_BASE if the number of NEW_AUX_ENT() changes */
234 #define NEW_AUX_ENT(id, val) \
242 * ARCH_DLINFO must come first so PPC can do its special alignment of
244 * update AT_VECTOR_SIZE_ARCH if the number of NEW_AUX_ENT() in
245 * ARCH_DLINFO changes
249 NEW_AUX_ENT(AT_HWCAP, ELF_HWCAP);
250 NEW_AUX_ENT(AT_PAGESZ, ELF_EXEC_PAGESIZE);
251 NEW_AUX_ENT(AT_CLKTCK, CLOCKS_PER_SEC);
252 NEW_AUX_ENT(AT_PHDR, load_addr + exec->e_phoff);
253 NEW_AUX_ENT(AT_PHENT, sizeof(struct elf_phdr));
254 NEW_AUX_ENT(AT_PHNUM, exec->e_phnum);
255 NEW_AUX_ENT(AT_BASE, interp_load_addr);
256 NEW_AUX_ENT(AT_FLAGS, 0);
257 NEW_AUX_ENT(AT_ENTRY, e_entry);
258 NEW_AUX_ENT(AT_UID, from_kuid_munged(cred->user_ns, cred->uid));
259 NEW_AUX_ENT(AT_EUID, from_kuid_munged(cred->user_ns, cred->euid));
260 NEW_AUX_ENT(AT_GID, from_kgid_munged(cred->user_ns, cred->gid));
261 NEW_AUX_ENT(AT_EGID, from_kgid_munged(cred->user_ns, cred->egid));
262 NEW_AUX_ENT(AT_SECURE, bprm->secureexec);
263 NEW_AUX_ENT(AT_RANDOM, (elf_addr_t)(unsigned long)u_rand_bytes);
265 NEW_AUX_ENT(AT_HWCAP2, ELF_HWCAP2);
267 NEW_AUX_ENT(AT_EXECFN, bprm->exec);
269 NEW_AUX_ENT(AT_PLATFORM,
270 (elf_addr_t)(unsigned long)u_platform);
272 if (k_base_platform) {
273 NEW_AUX_ENT(AT_BASE_PLATFORM,
274 (elf_addr_t)(unsigned long)u_base_platform);
276 if (bprm->interp_flags & BINPRM_FLAGS_EXECFD) {
277 NEW_AUX_ENT(AT_EXECFD, bprm->interp_data);
280 /* AT_NULL is zero; clear the rest too */
281 memset(elf_info, 0, (char *)mm->saved_auxv +
282 sizeof(mm->saved_auxv) - (char *)elf_info);
284 /* And advance past the AT_NULL entry. */
287 ei_index = elf_info - (elf_addr_t *)mm->saved_auxv;
288 sp = STACK_ADD(p, ei_index);
290 items = (argc + 1) + (envc + 1) + 1;
291 bprm->p = STACK_ROUND(sp, items);
293 /* Point sp at the lowest address on the stack */
294 #ifdef CONFIG_STACK_GROWSUP
295 sp = (elf_addr_t __user *)bprm->p - items - ei_index;
296 bprm->exec = (unsigned long)sp; /* XXX: PARISC HACK */
298 sp = (elf_addr_t __user *)bprm->p;
303 * Grow the stack manually; some architectures have a limit on how
304 * far ahead a user-space access may be in order to grow the stack.
306 vma = find_extend_vma(mm, bprm->p);
310 /* Now, let's put argc (and argv, envp if appropriate) on the stack */
311 if (__put_user(argc, sp++))
314 /* Populate list of argv pointers back to argv strings. */
315 p = mm->arg_end = mm->arg_start;
318 if (__put_user((elf_addr_t)p, sp++))
320 len = strnlen_user((void __user *)p, MAX_ARG_STRLEN);
321 if (!len || len > MAX_ARG_STRLEN)
325 if (__put_user(0, sp++))
329 /* Populate list of envp pointers back to envp strings. */
330 mm->env_end = mm->env_start = p;
333 if (__put_user((elf_addr_t)p, sp++))
335 len = strnlen_user((void __user *)p, MAX_ARG_STRLEN);
336 if (!len || len > MAX_ARG_STRLEN)
340 if (__put_user(0, sp++))
344 /* Put the elf_info on the stack in the right place. */
345 if (copy_to_user(sp, mm->saved_auxv, ei_index * sizeof(elf_addr_t)))
352 static unsigned long elf_map(struct file *filep, unsigned long addr,
353 const struct elf_phdr *eppnt, int prot, int type,
354 unsigned long total_size)
356 unsigned long map_addr;
357 unsigned long size = eppnt->p_filesz + ELF_PAGEOFFSET(eppnt->p_vaddr);
358 unsigned long off = eppnt->p_offset - ELF_PAGEOFFSET(eppnt->p_vaddr);
359 addr = ELF_PAGESTART(addr);
360 size = ELF_PAGEALIGN(size);
362 /* mmap() will return -EINVAL if given a zero size, but a
363 * segment with zero filesize is perfectly valid */
368 * total_size is the size of the ELF (interpreter) image.
369 * The _first_ mmap needs to know the full size, otherwise
370 * randomization might put this image into an overlapping
371 * position with the ELF binary image. (since size < total_size)
372 * So we first map the 'big' image - and unmap the remainder at
373 * the end. (which unmap is needed for ELF images with holes.)
376 total_size = ELF_PAGEALIGN(total_size);
377 map_addr = vm_mmap(filep, addr, total_size, prot, type, off);
378 if (!BAD_ADDR(map_addr))
379 vm_munmap(map_addr+size, total_size-size);
381 map_addr = vm_mmap(filep, addr, size, prot, type, off);
383 if ((type & MAP_FIXED_NOREPLACE) &&
384 PTR_ERR((void *)map_addr) == -EEXIST)
385 pr_info("%d (%s): Uhuuh, elf segment at %px requested but the memory is mapped already\n",
386 task_pid_nr(current), current->comm, (void *)addr);
391 #endif /* !elf_map */
393 static unsigned long total_mapping_size(const struct elf_phdr *cmds, int nr)
395 int i, first_idx = -1, last_idx = -1;
397 for (i = 0; i < nr; i++) {
398 if (cmds[i].p_type == PT_LOAD) {
407 return cmds[last_idx].p_vaddr + cmds[last_idx].p_memsz -
408 ELF_PAGESTART(cmds[first_idx].p_vaddr);
411 static int elf_read(struct file *file, void *buf, size_t len, loff_t pos)
415 rv = kernel_read(file, buf, len, &pos);
416 if (unlikely(rv != len)) {
417 return (rv < 0) ? rv : -EIO;
423 * load_elf_phdrs() - load ELF program headers
424 * @elf_ex: ELF header of the binary whose program headers should be loaded
425 * @elf_file: the opened ELF binary file
427 * Loads ELF program headers from the binary file elf_file, which has the ELF
428 * header pointed to by elf_ex, into a newly allocated array. The caller is
429 * responsible for freeing the allocated data. Returns an ERR_PTR upon failure.
431 static struct elf_phdr *load_elf_phdrs(const struct elfhdr *elf_ex,
432 struct file *elf_file)
434 struct elf_phdr *elf_phdata = NULL;
435 int retval, err = -1;
439 * If the size of this structure has changed, then punt, since
440 * we will be doing the wrong thing.
442 if (elf_ex->e_phentsize != sizeof(struct elf_phdr))
445 /* Sanity check the number of program headers... */
446 /* ...and their total size. */
447 size = sizeof(struct elf_phdr) * elf_ex->e_phnum;
448 if (size == 0 || size > 65536 || size > ELF_MIN_ALIGN)
451 elf_phdata = kmalloc(size, GFP_KERNEL);
455 /* Read in the program headers */
456 retval = elf_read(elf_file, elf_phdata, size, elf_ex->e_phoff);
472 #ifndef CONFIG_ARCH_BINFMT_ELF_STATE
475 * struct arch_elf_state - arch-specific ELF loading state
477 * This structure is used to preserve architecture specific data during
478 * the loading of an ELF file, throughout the checking of architecture
479 * specific ELF headers & through to the point where the ELF load is
480 * known to be proceeding (ie. SET_PERSONALITY).
482 * This implementation is a dummy for architectures which require no
485 struct arch_elf_state {
488 #define INIT_ARCH_ELF_STATE {}
491 * arch_elf_pt_proc() - check a PT_LOPROC..PT_HIPROC ELF program header
492 * @ehdr: The main ELF header
493 * @phdr: The program header to check
494 * @elf: The open ELF file
495 * @is_interp: True if the phdr is from the interpreter of the ELF being
496 * loaded, else false.
497 * @state: Architecture-specific state preserved throughout the process
498 * of loading the ELF.
500 * Inspects the program header phdr to validate its correctness and/or
501 * suitability for the system. Called once per ELF program header in the
502 * range PT_LOPROC to PT_HIPROC, for both the ELF being loaded and its
505 * Return: Zero to proceed with the ELF load, non-zero to fail the ELF load
506 * with that return code.
508 static inline int arch_elf_pt_proc(struct elfhdr *ehdr,
509 struct elf_phdr *phdr,
510 struct file *elf, bool is_interp,
511 struct arch_elf_state *state)
513 /* Dummy implementation, always proceed */
518 * arch_check_elf() - check an ELF executable
519 * @ehdr: The main ELF header
520 * @has_interp: True if the ELF has an interpreter, else false.
521 * @interp_ehdr: The interpreter's ELF header
522 * @state: Architecture-specific state preserved throughout the process
523 * of loading the ELF.
525 * Provides a final opportunity for architecture code to reject the loading
526 * of the ELF & cause an exec syscall to return an error. This is called after
527 * all program headers to be checked by arch_elf_pt_proc have been.
529 * Return: Zero to proceed with the ELF load, non-zero to fail the ELF load
530 * with that return code.
532 static inline int arch_check_elf(struct elfhdr *ehdr, bool has_interp,
533 struct elfhdr *interp_ehdr,
534 struct arch_elf_state *state)
536 /* Dummy implementation, always proceed */
540 #endif /* !CONFIG_ARCH_BINFMT_ELF_STATE */
542 static inline int make_prot(u32 p_flags)
555 /* This is much more generalized than the library routine read function,
556 so we keep this separate. Technically the library read function
557 is only provided so that we can read a.out libraries that have
560 static unsigned long load_elf_interp(struct elfhdr *interp_elf_ex,
561 struct file *interpreter,
562 unsigned long no_base, struct elf_phdr *interp_elf_phdata)
564 struct elf_phdr *eppnt;
565 unsigned long load_addr = 0;
566 int load_addr_set = 0;
567 unsigned long last_bss = 0, elf_bss = 0;
569 unsigned long error = ~0UL;
570 unsigned long total_size;
573 /* First of all, some simple consistency checks */
574 if (interp_elf_ex->e_type != ET_EXEC &&
575 interp_elf_ex->e_type != ET_DYN)
577 if (!elf_check_arch(interp_elf_ex) ||
578 elf_check_fdpic(interp_elf_ex))
580 if (!interpreter->f_op->mmap)
583 total_size = total_mapping_size(interp_elf_phdata,
584 interp_elf_ex->e_phnum);
590 eppnt = interp_elf_phdata;
591 for (i = 0; i < interp_elf_ex->e_phnum; i++, eppnt++) {
592 if (eppnt->p_type == PT_LOAD) {
593 int elf_type = MAP_PRIVATE | MAP_DENYWRITE;
594 int elf_prot = make_prot(eppnt->p_flags);
595 unsigned long vaddr = 0;
596 unsigned long k, map_addr;
598 vaddr = eppnt->p_vaddr;
599 if (interp_elf_ex->e_type == ET_EXEC || load_addr_set)
600 elf_type |= MAP_FIXED_NOREPLACE;
601 else if (no_base && interp_elf_ex->e_type == ET_DYN)
604 map_addr = elf_map(interpreter, load_addr + vaddr,
605 eppnt, elf_prot, elf_type, total_size);
608 if (BAD_ADDR(map_addr))
611 if (!load_addr_set &&
612 interp_elf_ex->e_type == ET_DYN) {
613 load_addr = map_addr - ELF_PAGESTART(vaddr);
618 * Check to see if the section's size will overflow the
619 * allowed task size. Note that p_filesz must always be
620 * <= p_memsize so it's only necessary to check p_memsz.
622 k = load_addr + eppnt->p_vaddr;
624 eppnt->p_filesz > eppnt->p_memsz ||
625 eppnt->p_memsz > TASK_SIZE ||
626 TASK_SIZE - eppnt->p_memsz < k) {
632 * Find the end of the file mapping for this phdr, and
633 * keep track of the largest address we see for this.
635 k = load_addr + eppnt->p_vaddr + eppnt->p_filesz;
640 * Do the same thing for the memory mapping - between
641 * elf_bss and last_bss is the bss section.
643 k = load_addr + eppnt->p_vaddr + eppnt->p_memsz;
652 * Now fill out the bss section: first pad the last page from
653 * the file up to the page boundary, and zero it from elf_bss
654 * up to the end of the page.
656 if (padzero(elf_bss)) {
661 * Next, align both the file and mem bss up to the page size,
662 * since this is where elf_bss was just zeroed up to, and where
663 * last_bss will end after the vm_brk_flags() below.
665 elf_bss = ELF_PAGEALIGN(elf_bss);
666 last_bss = ELF_PAGEALIGN(last_bss);
667 /* Finally, if there is still more bss to allocate, do it. */
668 if (last_bss > elf_bss) {
669 error = vm_brk_flags(elf_bss, last_bss - elf_bss,
670 bss_prot & PROT_EXEC ? VM_EXEC : 0);
681 * These are the functions used to load ELF style executables and shared
682 * libraries. There is no binary dependent code anywhere else.
685 static int load_elf_binary(struct linux_binprm *bprm)
687 struct file *interpreter = NULL; /* to shut gcc up */
688 unsigned long load_addr = 0, load_bias = 0;
689 int load_addr_set = 0;
691 struct elf_phdr *elf_ppnt, *elf_phdata, *interp_elf_phdata = NULL;
692 unsigned long elf_bss, elf_brk;
695 unsigned long elf_entry;
696 unsigned long e_entry;
697 unsigned long interp_load_addr = 0;
698 unsigned long start_code, end_code, start_data, end_data;
699 unsigned long reloc_func_desc __maybe_unused = 0;
700 int executable_stack = EXSTACK_DEFAULT;
701 struct elfhdr *elf_ex = (struct elfhdr *)bprm->buf;
702 struct elfhdr *interp_elf_ex = NULL;
703 struct arch_elf_state arch_state = INIT_ARCH_ELF_STATE;
704 struct mm_struct *mm;
705 struct pt_regs *regs;
708 /* First of all, some simple consistency checks */
709 if (memcmp(elf_ex->e_ident, ELFMAG, SELFMAG) != 0)
712 if (elf_ex->e_type != ET_EXEC && elf_ex->e_type != ET_DYN)
714 if (!elf_check_arch(elf_ex))
716 if (elf_check_fdpic(elf_ex))
718 if (!bprm->file->f_op->mmap)
721 elf_phdata = load_elf_phdrs(elf_ex, bprm->file);
725 elf_ppnt = elf_phdata;
726 for (i = 0; i < elf_ex->e_phnum; i++, elf_ppnt++) {
727 char *elf_interpreter;
729 if (elf_ppnt->p_type != PT_INTERP)
733 * This is the program interpreter used for shared libraries -
734 * for now assume that this is an a.out format binary.
737 if (elf_ppnt->p_filesz > PATH_MAX || elf_ppnt->p_filesz < 2)
741 elf_interpreter = kmalloc(elf_ppnt->p_filesz, GFP_KERNEL);
742 if (!elf_interpreter)
745 retval = elf_read(bprm->file, elf_interpreter, elf_ppnt->p_filesz,
748 goto out_free_interp;
749 /* make sure path is NULL terminated */
751 if (elf_interpreter[elf_ppnt->p_filesz - 1] != '\0')
752 goto out_free_interp;
754 interpreter = open_exec(elf_interpreter);
755 kfree(elf_interpreter);
756 retval = PTR_ERR(interpreter);
757 if (IS_ERR(interpreter))
761 * If the binary is not readable then enforce mm->dumpable = 0
762 * regardless of the interpreter's permissions.
764 would_dump(bprm, interpreter);
766 interp_elf_ex = kmalloc(sizeof(*interp_elf_ex), GFP_KERNEL);
767 if (!interp_elf_ex) {
772 /* Get the exec headers */
773 retval = elf_read(interpreter, interp_elf_ex,
774 sizeof(*interp_elf_ex), 0);
776 goto out_free_dentry;
781 kfree(elf_interpreter);
785 elf_ppnt = elf_phdata;
786 for (i = 0; i < elf_ex->e_phnum; i++, elf_ppnt++)
787 switch (elf_ppnt->p_type) {
789 if (elf_ppnt->p_flags & PF_X)
790 executable_stack = EXSTACK_ENABLE_X;
792 executable_stack = EXSTACK_DISABLE_X;
795 case PT_LOPROC ... PT_HIPROC:
796 retval = arch_elf_pt_proc(elf_ex, elf_ppnt,
800 goto out_free_dentry;
804 /* Some simple consistency checks for the interpreter */
807 /* Not an ELF interpreter */
808 if (memcmp(interp_elf_ex->e_ident, ELFMAG, SELFMAG) != 0)
809 goto out_free_dentry;
810 /* Verify the interpreter has a valid arch */
811 if (!elf_check_arch(interp_elf_ex) ||
812 elf_check_fdpic(interp_elf_ex))
813 goto out_free_dentry;
815 /* Load the interpreter program headers */
816 interp_elf_phdata = load_elf_phdrs(interp_elf_ex,
818 if (!interp_elf_phdata)
819 goto out_free_dentry;
821 /* Pass PT_LOPROC..PT_HIPROC headers to arch code */
822 elf_ppnt = interp_elf_phdata;
823 for (i = 0; i < interp_elf_ex->e_phnum; i++, elf_ppnt++)
824 switch (elf_ppnt->p_type) {
825 case PT_LOPROC ... PT_HIPROC:
826 retval = arch_elf_pt_proc(interp_elf_ex,
827 elf_ppnt, interpreter,
830 goto out_free_dentry;
836 * Allow arch code to reject the ELF at this point, whilst it's
837 * still possible to return an error to the code that invoked
840 retval = arch_check_elf(elf_ex,
841 !!interpreter, interp_elf_ex,
844 goto out_free_dentry;
846 /* Flush all traces of the currently running executable */
847 retval = flush_old_exec(bprm);
849 goto out_free_dentry;
851 /* Do this immediately, since STACK_TOP as used in setup_arg_pages
852 may depend on the personality. */
853 SET_PERSONALITY2(*elf_ex, &arch_state);
854 if (elf_read_implies_exec(*elf_ex, executable_stack))
855 current->personality |= READ_IMPLIES_EXEC;
857 if (!(current->personality & ADDR_NO_RANDOMIZE) && randomize_va_space)
858 current->flags |= PF_RANDOMIZE;
860 setup_new_exec(bprm);
862 /* Do this so that we can load the interpreter, if need be. We will
863 change some of these later */
864 retval = setup_arg_pages(bprm, randomize_stack_top(STACK_TOP),
867 goto out_free_dentry;
877 /* Now we do a little grungy work by mmapping the ELF image into
878 the correct location in memory. */
879 for(i = 0, elf_ppnt = elf_phdata;
880 i < elf_ex->e_phnum; i++, elf_ppnt++) {
881 int elf_prot, elf_flags;
882 unsigned long k, vaddr;
883 unsigned long total_size = 0;
885 if (elf_ppnt->p_type != PT_LOAD)
888 if (unlikely (elf_brk > elf_bss)) {
891 /* There was a PT_LOAD segment with p_memsz > p_filesz
892 before this one. Map anonymous pages, if needed,
893 and clear the area. */
894 retval = set_brk(elf_bss + load_bias,
898 goto out_free_dentry;
899 nbyte = ELF_PAGEOFFSET(elf_bss);
901 nbyte = ELF_MIN_ALIGN - nbyte;
902 if (nbyte > elf_brk - elf_bss)
903 nbyte = elf_brk - elf_bss;
904 if (clear_user((void __user *)elf_bss +
907 * This bss-zeroing can fail if the ELF
908 * file specifies odd protections. So
909 * we don't check the return value
915 elf_prot = make_prot(elf_ppnt->p_flags);
917 elf_flags = MAP_PRIVATE | MAP_DENYWRITE | MAP_EXECUTABLE;
919 vaddr = elf_ppnt->p_vaddr;
921 * If we are loading ET_EXEC or we have already performed
922 * the ET_DYN load_addr calculations, proceed normally.
924 if (elf_ex->e_type == ET_EXEC || load_addr_set) {
925 elf_flags |= MAP_FIXED;
926 } else if (elf_ex->e_type == ET_DYN) {
928 * This logic is run once for the first LOAD Program
929 * Header for ET_DYN binaries to calculate the
930 * randomization (load_bias) for all the LOAD
931 * Program Headers, and to calculate the entire
932 * size of the ELF mapping (total_size). (Note that
933 * load_addr_set is set to true later once the
934 * initial mapping is performed.)
936 * There are effectively two types of ET_DYN
937 * binaries: programs (i.e. PIE: ET_DYN with INTERP)
938 * and loaders (ET_DYN without INTERP, since they
939 * _are_ the ELF interpreter). The loaders must
940 * be loaded away from programs since the program
941 * may otherwise collide with the loader (especially
942 * for ET_EXEC which does not have a randomized
943 * position). For example to handle invocations of
944 * "./ld.so someprog" to test out a new version of
945 * the loader, the subsequent program that the
946 * loader loads must avoid the loader itself, so
947 * they cannot share the same load range. Sufficient
948 * room for the brk must be allocated with the
949 * loader as well, since brk must be available with
952 * Therefore, programs are loaded offset from
953 * ELF_ET_DYN_BASE and loaders are loaded into the
954 * independently randomized mmap region (0 load_bias
955 * without MAP_FIXED).
958 load_bias = ELF_ET_DYN_BASE;
959 if (current->flags & PF_RANDOMIZE)
960 load_bias += arch_mmap_rnd();
961 elf_flags |= MAP_FIXED;
966 * Since load_bias is used for all subsequent loading
967 * calculations, we must lower it by the first vaddr
968 * so that the remaining calculations based on the
969 * ELF vaddrs will be correctly offset. The result
970 * is then page aligned.
972 load_bias = ELF_PAGESTART(load_bias - vaddr);
974 total_size = total_mapping_size(elf_phdata,
978 goto out_free_dentry;
982 error = elf_map(bprm->file, load_bias + vaddr, elf_ppnt,
983 elf_prot, elf_flags, total_size);
984 if (BAD_ADDR(error)) {
985 retval = IS_ERR((void *)error) ?
986 PTR_ERR((void*)error) : -EINVAL;
987 goto out_free_dentry;
990 if (!load_addr_set) {
992 load_addr = (elf_ppnt->p_vaddr - elf_ppnt->p_offset);
993 if (elf_ex->e_type == ET_DYN) {
995 ELF_PAGESTART(load_bias + vaddr);
996 load_addr += load_bias;
997 reloc_func_desc = load_bias;
1000 k = elf_ppnt->p_vaddr;
1001 if ((elf_ppnt->p_flags & PF_X) && k < start_code)
1007 * Check to see if the section's size will overflow the
1008 * allowed task size. Note that p_filesz must always be
1009 * <= p_memsz so it is only necessary to check p_memsz.
1011 if (BAD_ADDR(k) || elf_ppnt->p_filesz > elf_ppnt->p_memsz ||
1012 elf_ppnt->p_memsz > TASK_SIZE ||
1013 TASK_SIZE - elf_ppnt->p_memsz < k) {
1014 /* set_brk can never work. Avoid overflows. */
1016 goto out_free_dentry;
1019 k = elf_ppnt->p_vaddr + elf_ppnt->p_filesz;
1023 if ((elf_ppnt->p_flags & PF_X) && end_code < k)
1027 k = elf_ppnt->p_vaddr + elf_ppnt->p_memsz;
1029 bss_prot = elf_prot;
1034 e_entry = elf_ex->e_entry + load_bias;
1035 elf_bss += load_bias;
1036 elf_brk += load_bias;
1037 start_code += load_bias;
1038 end_code += load_bias;
1039 start_data += load_bias;
1040 end_data += load_bias;
1042 /* Calling set_brk effectively mmaps the pages that we need
1043 * for the bss and break sections. We must do this before
1044 * mapping in the interpreter, to make sure it doesn't wind
1045 * up getting placed where the bss needs to go.
1047 retval = set_brk(elf_bss, elf_brk, bss_prot);
1049 goto out_free_dentry;
1050 if (likely(elf_bss != elf_brk) && unlikely(padzero(elf_bss))) {
1051 retval = -EFAULT; /* Nobody gets to see this, but.. */
1052 goto out_free_dentry;
1056 elf_entry = load_elf_interp(interp_elf_ex,
1058 load_bias, interp_elf_phdata);
1059 if (!IS_ERR((void *)elf_entry)) {
1061 * load_elf_interp() returns relocation
1064 interp_load_addr = elf_entry;
1065 elf_entry += interp_elf_ex->e_entry;
1067 if (BAD_ADDR(elf_entry)) {
1068 retval = IS_ERR((void *)elf_entry) ?
1069 (int)elf_entry : -EINVAL;
1070 goto out_free_dentry;
1072 reloc_func_desc = interp_load_addr;
1074 allow_write_access(interpreter);
1077 kfree(interp_elf_ex);
1078 kfree(interp_elf_phdata);
1080 elf_entry = e_entry;
1081 if (BAD_ADDR(elf_entry)) {
1083 goto out_free_dentry;
1089 set_binfmt(&elf_format);
1091 #ifdef ARCH_HAS_SETUP_ADDITIONAL_PAGES
1092 retval = arch_setup_additional_pages(bprm, !!interpreter);
1095 #endif /* ARCH_HAS_SETUP_ADDITIONAL_PAGES */
1097 retval = create_elf_tables(bprm, elf_ex,
1098 load_addr, interp_load_addr, e_entry);
1103 mm->end_code = end_code;
1104 mm->start_code = start_code;
1105 mm->start_data = start_data;
1106 mm->end_data = end_data;
1107 mm->start_stack = bprm->p;
1109 if ((current->flags & PF_RANDOMIZE) && (randomize_va_space > 1)) {
1111 * For architectures with ELF randomization, when executing
1112 * a loader directly (i.e. no interpreter listed in ELF
1113 * headers), move the brk area out of the mmap region
1114 * (since it grows up, and may collide early with the stack
1115 * growing down), and into the unused ELF_ET_DYN_BASE region.
1117 if (IS_ENABLED(CONFIG_ARCH_HAS_ELF_RANDOMIZE) &&
1118 elf_ex->e_type == ET_DYN && !interpreter) {
1119 mm->brk = mm->start_brk = ELF_ET_DYN_BASE;
1122 mm->brk = mm->start_brk = arch_randomize_brk(mm);
1123 #ifdef compat_brk_randomized
1124 current->brk_randomized = 1;
1128 if (current->personality & MMAP_PAGE_ZERO) {
1129 /* Why this, you ask??? Well SVr4 maps page 0 as read-only,
1130 and some applications "depend" upon this behavior.
1131 Since we do not have the power to recompile these, we
1132 emulate the SVr4 behavior. Sigh. */
1133 error = vm_mmap(NULL, 0, PAGE_SIZE, PROT_READ | PROT_EXEC,
1134 MAP_FIXED | MAP_PRIVATE, 0);
1137 regs = current_pt_regs();
1138 #ifdef ELF_PLAT_INIT
1140 * The ABI may specify that certain registers be set up in special
1141 * ways (on i386 %edx is the address of a DT_FINI function, for
1142 * example. In addition, it may also specify (eg, PowerPC64 ELF)
1143 * that the e_entry field is the address of the function descriptor
1144 * for the startup routine, rather than the address of the startup
1145 * routine itself. This macro performs whatever initialization to
1146 * the regs structure is required as well as any relocations to the
1147 * function descriptor entries when executing dynamically links apps.
1149 ELF_PLAT_INIT(regs, reloc_func_desc);
1152 finalize_exec(bprm);
1153 start_thread(regs, elf_entry, bprm->p);
1160 kfree(interp_elf_ex);
1161 kfree(interp_elf_phdata);
1162 allow_write_access(interpreter);
1170 #ifdef CONFIG_USELIB
1171 /* This is really simpleminded and specialized - we are loading an
1172 a.out library that is given an ELF header. */
1173 static int load_elf_library(struct file *file)
1175 struct elf_phdr *elf_phdata;
1176 struct elf_phdr *eppnt;
1177 unsigned long elf_bss, bss, len;
1178 int retval, error, i, j;
1179 struct elfhdr elf_ex;
1182 retval = elf_read(file, &elf_ex, sizeof(elf_ex), 0);
1186 if (memcmp(elf_ex.e_ident, ELFMAG, SELFMAG) != 0)
1189 /* First of all, some simple consistency checks */
1190 if (elf_ex.e_type != ET_EXEC || elf_ex.e_phnum > 2 ||
1191 !elf_check_arch(&elf_ex) || !file->f_op->mmap)
1193 if (elf_check_fdpic(&elf_ex))
1196 /* Now read in all of the header information */
1198 j = sizeof(struct elf_phdr) * elf_ex.e_phnum;
1199 /* j < ELF_MIN_ALIGN because elf_ex.e_phnum <= 2 */
1202 elf_phdata = kmalloc(j, GFP_KERNEL);
1208 retval = elf_read(file, eppnt, j, elf_ex.e_phoff);
1212 for (j = 0, i = 0; i<elf_ex.e_phnum; i++)
1213 if ((eppnt + i)->p_type == PT_LOAD)
1218 while (eppnt->p_type != PT_LOAD)
1221 /* Now use mmap to map the library into memory. */
1222 error = vm_mmap(file,
1223 ELF_PAGESTART(eppnt->p_vaddr),
1225 ELF_PAGEOFFSET(eppnt->p_vaddr)),
1226 PROT_READ | PROT_WRITE | PROT_EXEC,
1227 MAP_FIXED_NOREPLACE | MAP_PRIVATE | MAP_DENYWRITE,
1229 ELF_PAGEOFFSET(eppnt->p_vaddr)));
1230 if (error != ELF_PAGESTART(eppnt->p_vaddr))
1233 elf_bss = eppnt->p_vaddr + eppnt->p_filesz;
1234 if (padzero(elf_bss)) {
1239 len = ELF_PAGEALIGN(eppnt->p_filesz + eppnt->p_vaddr);
1240 bss = ELF_PAGEALIGN(eppnt->p_memsz + eppnt->p_vaddr);
1242 error = vm_brk(len, bss - len);
1253 #endif /* #ifdef CONFIG_USELIB */
1255 #ifdef CONFIG_ELF_CORE
1259 * Modelled on fs/exec.c:aout_core_dump()
1260 * Jeremy Fitzhardinge <jeremy@sw.oz.au>
1264 * The purpose of always_dump_vma() is to make sure that special kernel mappings
1265 * that are useful for post-mortem analysis are included in every core dump.
1266 * In that way we ensure that the core dump is fully interpretable later
1267 * without matching up the same kernel and hardware config to see what PC values
1268 * meant. These special mappings include - vDSO, vsyscall, and other
1269 * architecture specific mappings
1271 static bool always_dump_vma(struct vm_area_struct *vma)
1273 /* Any vsyscall mappings? */
1274 if (vma == get_gate_vma(vma->vm_mm))
1278 * Assume that all vmas with a .name op should always be dumped.
1279 * If this changes, a new vm_ops field can easily be added.
1281 if (vma->vm_ops && vma->vm_ops->name && vma->vm_ops->name(vma))
1285 * arch_vma_name() returns non-NULL for special architecture mappings,
1286 * such as vDSO sections.
1288 if (arch_vma_name(vma))
1295 * Decide what to dump of a segment, part, all or none.
1297 static unsigned long vma_dump_size(struct vm_area_struct *vma,
1298 unsigned long mm_flags)
1300 #define FILTER(type) (mm_flags & (1UL << MMF_DUMP_##type))
1302 /* always dump the vdso and vsyscall sections */
1303 if (always_dump_vma(vma))
1306 if (vma->vm_flags & VM_DONTDUMP)
1309 /* support for DAX */
1310 if (vma_is_dax(vma)) {
1311 if ((vma->vm_flags & VM_SHARED) && FILTER(DAX_SHARED))
1313 if (!(vma->vm_flags & VM_SHARED) && FILTER(DAX_PRIVATE))
1318 /* Hugetlb memory check */
1319 if (is_vm_hugetlb_page(vma)) {
1320 if ((vma->vm_flags & VM_SHARED) && FILTER(HUGETLB_SHARED))
1322 if (!(vma->vm_flags & VM_SHARED) && FILTER(HUGETLB_PRIVATE))
1327 /* Do not dump I/O mapped devices or special mappings */
1328 if (vma->vm_flags & VM_IO)
1331 /* By default, dump shared memory if mapped from an anonymous file. */
1332 if (vma->vm_flags & VM_SHARED) {
1333 if (file_inode(vma->vm_file)->i_nlink == 0 ?
1334 FILTER(ANON_SHARED) : FILTER(MAPPED_SHARED))
1339 /* Dump segments that have been written to. */
1340 if (vma->anon_vma && FILTER(ANON_PRIVATE))
1342 if (vma->vm_file == NULL)
1345 if (FILTER(MAPPED_PRIVATE))
1349 * If this looks like the beginning of a DSO or executable mapping,
1350 * check for an ELF header. If we find one, dump the first page to
1351 * aid in determining what was mapped here.
1353 if (FILTER(ELF_HEADERS) &&
1354 vma->vm_pgoff == 0 && (vma->vm_flags & VM_READ)) {
1355 u32 __user *header = (u32 __user *) vma->vm_start;
1357 mm_segment_t fs = get_fs();
1359 * Doing it this way gets the constant folded by GCC.
1363 char elfmag[SELFMAG];
1365 BUILD_BUG_ON(SELFMAG != sizeof word);
1366 magic.elfmag[EI_MAG0] = ELFMAG0;
1367 magic.elfmag[EI_MAG1] = ELFMAG1;
1368 magic.elfmag[EI_MAG2] = ELFMAG2;
1369 magic.elfmag[EI_MAG3] = ELFMAG3;
1371 * Switch to the user "segment" for get_user(),
1372 * then put back what elf_core_dump() had in place.
1375 if (unlikely(get_user(word, header)))
1378 if (word == magic.cmp)
1387 return vma->vm_end - vma->vm_start;
1390 /* An ELF note in memory */
1395 unsigned int datasz;
1399 static int notesize(struct memelfnote *en)
1403 sz = sizeof(struct elf_note);
1404 sz += roundup(strlen(en->name) + 1, 4);
1405 sz += roundup(en->datasz, 4);
1410 static int writenote(struct memelfnote *men, struct coredump_params *cprm)
1413 en.n_namesz = strlen(men->name) + 1;
1414 en.n_descsz = men->datasz;
1415 en.n_type = men->type;
1417 return dump_emit(cprm, &en, sizeof(en)) &&
1418 dump_emit(cprm, men->name, en.n_namesz) && dump_align(cprm, 4) &&
1419 dump_emit(cprm, men->data, men->datasz) && dump_align(cprm, 4);
1422 static void fill_elf_header(struct elfhdr *elf, int segs,
1423 u16 machine, u32 flags)
1425 memset(elf, 0, sizeof(*elf));
1427 memcpy(elf->e_ident, ELFMAG, SELFMAG);
1428 elf->e_ident[EI_CLASS] = ELF_CLASS;
1429 elf->e_ident[EI_DATA] = ELF_DATA;
1430 elf->e_ident[EI_VERSION] = EV_CURRENT;
1431 elf->e_ident[EI_OSABI] = ELF_OSABI;
1433 elf->e_type = ET_CORE;
1434 elf->e_machine = machine;
1435 elf->e_version = EV_CURRENT;
1436 elf->e_phoff = sizeof(struct elfhdr);
1437 elf->e_flags = flags;
1438 elf->e_ehsize = sizeof(struct elfhdr);
1439 elf->e_phentsize = sizeof(struct elf_phdr);
1440 elf->e_phnum = segs;
1443 static void fill_elf_note_phdr(struct elf_phdr *phdr, int sz, loff_t offset)
1445 phdr->p_type = PT_NOTE;
1446 phdr->p_offset = offset;
1449 phdr->p_filesz = sz;
1455 static void fill_note(struct memelfnote *note, const char *name, int type,
1456 unsigned int sz, void *data)
1465 * fill up all the fields in prstatus from the given task struct, except
1466 * registers which need to be filled up separately.
1468 static void fill_prstatus(struct elf_prstatus *prstatus,
1469 struct task_struct *p, long signr)
1471 prstatus->pr_info.si_signo = prstatus->pr_cursig = signr;
1472 prstatus->pr_sigpend = p->pending.signal.sig[0];
1473 prstatus->pr_sighold = p->blocked.sig[0];
1475 prstatus->pr_ppid = task_pid_vnr(rcu_dereference(p->real_parent));
1477 prstatus->pr_pid = task_pid_vnr(p);
1478 prstatus->pr_pgrp = task_pgrp_vnr(p);
1479 prstatus->pr_sid = task_session_vnr(p);
1480 if (thread_group_leader(p)) {
1481 struct task_cputime cputime;
1484 * This is the record for the group leader. It shows the
1485 * group-wide total, not its individual thread total.
1487 thread_group_cputime(p, &cputime);
1488 prstatus->pr_utime = ns_to_kernel_old_timeval(cputime.utime);
1489 prstatus->pr_stime = ns_to_kernel_old_timeval(cputime.stime);
1493 task_cputime(p, &utime, &stime);
1494 prstatus->pr_utime = ns_to_kernel_old_timeval(utime);
1495 prstatus->pr_stime = ns_to_kernel_old_timeval(stime);
1498 prstatus->pr_cutime = ns_to_kernel_old_timeval(p->signal->cutime);
1499 prstatus->pr_cstime = ns_to_kernel_old_timeval(p->signal->cstime);
1502 static int fill_psinfo(struct elf_prpsinfo *psinfo, struct task_struct *p,
1503 struct mm_struct *mm)
1505 const struct cred *cred;
1506 unsigned int i, len;
1508 /* first copy the parameters from user space */
1509 memset(psinfo, 0, sizeof(struct elf_prpsinfo));
1511 len = mm->arg_end - mm->arg_start;
1512 if (len >= ELF_PRARGSZ)
1513 len = ELF_PRARGSZ-1;
1514 if (copy_from_user(&psinfo->pr_psargs,
1515 (const char __user *)mm->arg_start, len))
1517 for(i = 0; i < len; i++)
1518 if (psinfo->pr_psargs[i] == 0)
1519 psinfo->pr_psargs[i] = ' ';
1520 psinfo->pr_psargs[len] = 0;
1523 psinfo->pr_ppid = task_pid_vnr(rcu_dereference(p->real_parent));
1525 psinfo->pr_pid = task_pid_vnr(p);
1526 psinfo->pr_pgrp = task_pgrp_vnr(p);
1527 psinfo->pr_sid = task_session_vnr(p);
1529 i = p->state ? ffz(~p->state) + 1 : 0;
1530 psinfo->pr_state = i;
1531 psinfo->pr_sname = (i > 5) ? '.' : "RSDTZW"[i];
1532 psinfo->pr_zomb = psinfo->pr_sname == 'Z';
1533 psinfo->pr_nice = task_nice(p);
1534 psinfo->pr_flag = p->flags;
1536 cred = __task_cred(p);
1537 SET_UID(psinfo->pr_uid, from_kuid_munged(cred->user_ns, cred->uid));
1538 SET_GID(psinfo->pr_gid, from_kgid_munged(cred->user_ns, cred->gid));
1540 strncpy(psinfo->pr_fname, p->comm, sizeof(psinfo->pr_fname));
1545 static void fill_auxv_note(struct memelfnote *note, struct mm_struct *mm)
1547 elf_addr_t *auxv = (elf_addr_t *) mm->saved_auxv;
1551 while (auxv[i - 2] != AT_NULL);
1552 fill_note(note, "CORE", NT_AUXV, i * sizeof(elf_addr_t), auxv);
1555 static void fill_siginfo_note(struct memelfnote *note, user_siginfo_t *csigdata,
1556 const kernel_siginfo_t *siginfo)
1558 mm_segment_t old_fs = get_fs();
1560 copy_siginfo_to_user((user_siginfo_t __user *) csigdata, siginfo);
1562 fill_note(note, "CORE", NT_SIGINFO, sizeof(*csigdata), csigdata);
1565 #define MAX_FILE_NOTE_SIZE (4*1024*1024)
1567 * Format of NT_FILE note:
1569 * long count -- how many files are mapped
1570 * long page_size -- units for file_ofs
1571 * array of [COUNT] elements of
1575 * followed by COUNT filenames in ASCII: "FILE1" NUL "FILE2" NUL...
1577 static int fill_files_note(struct memelfnote *note)
1579 struct mm_struct *mm = current->mm;
1580 struct vm_area_struct *vma;
1581 unsigned count, size, names_ofs, remaining, n;
1583 user_long_t *start_end_ofs;
1584 char *name_base, *name_curpos;
1586 /* *Estimated* file count and total data size needed */
1587 count = mm->map_count;
1588 if (count > UINT_MAX / 64)
1592 names_ofs = (2 + 3 * count) * sizeof(data[0]);
1594 if (size >= MAX_FILE_NOTE_SIZE) /* paranoia check */
1596 size = round_up(size, PAGE_SIZE);
1598 * "size" can be 0 here legitimately.
1599 * Let it ENOMEM and omit NT_FILE section which will be empty anyway.
1601 data = kvmalloc(size, GFP_KERNEL);
1602 if (ZERO_OR_NULL_PTR(data))
1605 start_end_ofs = data + 2;
1606 name_base = name_curpos = ((char *)data) + names_ofs;
1607 remaining = size - names_ofs;
1609 for (vma = mm->mmap; vma != NULL; vma = vma->vm_next) {
1611 const char *filename;
1613 file = vma->vm_file;
1616 filename = file_path(file, name_curpos, remaining);
1617 if (IS_ERR(filename)) {
1618 if (PTR_ERR(filename) == -ENAMETOOLONG) {
1620 size = size * 5 / 4;
1626 /* file_path() fills at the end, move name down */
1627 /* n = strlen(filename) + 1: */
1628 n = (name_curpos + remaining) - filename;
1629 remaining = filename - name_curpos;
1630 memmove(name_curpos, filename, n);
1633 *start_end_ofs++ = vma->vm_start;
1634 *start_end_ofs++ = vma->vm_end;
1635 *start_end_ofs++ = vma->vm_pgoff;
1639 /* Now we know exact count of files, can store it */
1641 data[1] = PAGE_SIZE;
1643 * Count usually is less than mm->map_count,
1644 * we need to move filenames down.
1646 n = mm->map_count - count;
1648 unsigned shift_bytes = n * 3 * sizeof(data[0]);
1649 memmove(name_base - shift_bytes, name_base,
1650 name_curpos - name_base);
1651 name_curpos -= shift_bytes;
1654 size = name_curpos - (char *)data;
1655 fill_note(note, "CORE", NT_FILE, size, data);
1659 #ifdef CORE_DUMP_USE_REGSET
1660 #include <linux/regset.h>
1662 struct elf_thread_core_info {
1663 struct elf_thread_core_info *next;
1664 struct task_struct *task;
1665 struct elf_prstatus prstatus;
1666 struct memelfnote notes[0];
1669 struct elf_note_info {
1670 struct elf_thread_core_info *thread;
1671 struct memelfnote psinfo;
1672 struct memelfnote signote;
1673 struct memelfnote auxv;
1674 struct memelfnote files;
1675 user_siginfo_t csigdata;
1681 * When a regset has a writeback hook, we call it on each thread before
1682 * dumping user memory. On register window machines, this makes sure the
1683 * user memory backing the register data is up to date before we read it.
1685 static void do_thread_regset_writeback(struct task_struct *task,
1686 const struct user_regset *regset)
1688 if (regset->writeback)
1689 regset->writeback(task, regset, 1);
1692 #ifndef PRSTATUS_SIZE
1693 #define PRSTATUS_SIZE(S, R) sizeof(S)
1696 #ifndef SET_PR_FPVALID
1697 #define SET_PR_FPVALID(S, V, R) ((S)->pr_fpvalid = (V))
1700 static int fill_thread_core_info(struct elf_thread_core_info *t,
1701 const struct user_regset_view *view,
1702 long signr, size_t *total)
1705 unsigned int regset0_size = regset_size(t->task, &view->regsets[0]);
1708 * NT_PRSTATUS is the one special case, because the regset data
1709 * goes into the pr_reg field inside the note contents, rather
1710 * than being the whole note contents. We fill the reset in here.
1711 * We assume that regset 0 is NT_PRSTATUS.
1713 fill_prstatus(&t->prstatus, t->task, signr);
1714 (void) view->regsets[0].get(t->task, &view->regsets[0], 0, regset0_size,
1715 &t->prstatus.pr_reg, NULL);
1717 fill_note(&t->notes[0], "CORE", NT_PRSTATUS,
1718 PRSTATUS_SIZE(t->prstatus, regset0_size), &t->prstatus);
1719 *total += notesize(&t->notes[0]);
1721 do_thread_regset_writeback(t->task, &view->regsets[0]);
1724 * Each other regset might generate a note too. For each regset
1725 * that has no core_note_type or is inactive, we leave t->notes[i]
1726 * all zero and we'll know to skip writing it later.
1728 for (i = 1; i < view->n; ++i) {
1729 const struct user_regset *regset = &view->regsets[i];
1730 do_thread_regset_writeback(t->task, regset);
1731 if (regset->core_note_type && regset->get &&
1732 (!regset->active || regset->active(t->task, regset) > 0)) {
1734 size_t size = regset_size(t->task, regset);
1735 void *data = kmalloc(size, GFP_KERNEL);
1736 if (unlikely(!data))
1738 ret = regset->get(t->task, regset,
1739 0, size, data, NULL);
1743 if (regset->core_note_type != NT_PRFPREG)
1744 fill_note(&t->notes[i], "LINUX",
1745 regset->core_note_type,
1748 SET_PR_FPVALID(&t->prstatus,
1750 fill_note(&t->notes[i], "CORE",
1751 NT_PRFPREG, size, data);
1753 *total += notesize(&t->notes[i]);
1761 static int fill_note_info(struct elfhdr *elf, int phdrs,
1762 struct elf_note_info *info,
1763 const kernel_siginfo_t *siginfo, struct pt_regs *regs)
1765 struct task_struct *dump_task = current;
1766 const struct user_regset_view *view = task_user_regset_view(dump_task);
1767 struct elf_thread_core_info *t;
1768 struct elf_prpsinfo *psinfo;
1769 struct core_thread *ct;
1773 info->thread = NULL;
1775 psinfo = kmalloc(sizeof(*psinfo), GFP_KERNEL);
1776 if (psinfo == NULL) {
1777 info->psinfo.data = NULL; /* So we don't free this wrongly */
1781 fill_note(&info->psinfo, "CORE", NT_PRPSINFO, sizeof(*psinfo), psinfo);
1784 * Figure out how many notes we're going to need for each thread.
1786 info->thread_notes = 0;
1787 for (i = 0; i < view->n; ++i)
1788 if (view->regsets[i].core_note_type != 0)
1789 ++info->thread_notes;
1792 * Sanity check. We rely on regset 0 being in NT_PRSTATUS,
1793 * since it is our one special case.
1795 if (unlikely(info->thread_notes == 0) ||
1796 unlikely(view->regsets[0].core_note_type != NT_PRSTATUS)) {
1802 * Initialize the ELF file header.
1804 fill_elf_header(elf, phdrs,
1805 view->e_machine, view->e_flags);
1808 * Allocate a structure for each thread.
1810 for (ct = &dump_task->mm->core_state->dumper; ct; ct = ct->next) {
1811 t = kzalloc(offsetof(struct elf_thread_core_info,
1812 notes[info->thread_notes]),
1818 if (ct->task == dump_task || !info->thread) {
1819 t->next = info->thread;
1823 * Make sure to keep the original task at
1824 * the head of the list.
1826 t->next = info->thread->next;
1827 info->thread->next = t;
1832 * Now fill in each thread's information.
1834 for (t = info->thread; t != NULL; t = t->next)
1835 if (!fill_thread_core_info(t, view, siginfo->si_signo, &info->size))
1839 * Fill in the two process-wide notes.
1841 fill_psinfo(psinfo, dump_task->group_leader, dump_task->mm);
1842 info->size += notesize(&info->psinfo);
1844 fill_siginfo_note(&info->signote, &info->csigdata, siginfo);
1845 info->size += notesize(&info->signote);
1847 fill_auxv_note(&info->auxv, current->mm);
1848 info->size += notesize(&info->auxv);
1850 if (fill_files_note(&info->files) == 0)
1851 info->size += notesize(&info->files);
1856 static size_t get_note_info_size(struct elf_note_info *info)
1862 * Write all the notes for each thread. When writing the first thread, the
1863 * process-wide notes are interleaved after the first thread-specific note.
1865 static int write_note_info(struct elf_note_info *info,
1866 struct coredump_params *cprm)
1869 struct elf_thread_core_info *t = info->thread;
1874 if (!writenote(&t->notes[0], cprm))
1877 if (first && !writenote(&info->psinfo, cprm))
1879 if (first && !writenote(&info->signote, cprm))
1881 if (first && !writenote(&info->auxv, cprm))
1883 if (first && info->files.data &&
1884 !writenote(&info->files, cprm))
1887 for (i = 1; i < info->thread_notes; ++i)
1888 if (t->notes[i].data &&
1889 !writenote(&t->notes[i], cprm))
1899 static void free_note_info(struct elf_note_info *info)
1901 struct elf_thread_core_info *threads = info->thread;
1904 struct elf_thread_core_info *t = threads;
1906 WARN_ON(t->notes[0].data && t->notes[0].data != &t->prstatus);
1907 for (i = 1; i < info->thread_notes; ++i)
1908 kfree(t->notes[i].data);
1911 kfree(info->psinfo.data);
1912 kvfree(info->files.data);
1917 /* Here is the structure in which status of each thread is captured. */
1918 struct elf_thread_status
1920 struct list_head list;
1921 struct elf_prstatus prstatus; /* NT_PRSTATUS */
1922 elf_fpregset_t fpu; /* NT_PRFPREG */
1923 struct task_struct *thread;
1924 #ifdef ELF_CORE_COPY_XFPREGS
1925 elf_fpxregset_t xfpu; /* ELF_CORE_XFPREG_TYPE */
1927 struct memelfnote notes[3];
1932 * In order to add the specific thread information for the elf file format,
1933 * we need to keep a linked list of every threads pr_status and then create
1934 * a single section for them in the final core file.
1936 static int elf_dump_thread_status(long signr, struct elf_thread_status *t)
1939 struct task_struct *p = t->thread;
1942 fill_prstatus(&t->prstatus, p, signr);
1943 elf_core_copy_task_regs(p, &t->prstatus.pr_reg);
1945 fill_note(&t->notes[0], "CORE", NT_PRSTATUS, sizeof(t->prstatus),
1948 sz += notesize(&t->notes[0]);
1950 if ((t->prstatus.pr_fpvalid = elf_core_copy_task_fpregs(p, NULL,
1952 fill_note(&t->notes[1], "CORE", NT_PRFPREG, sizeof(t->fpu),
1955 sz += notesize(&t->notes[1]);
1958 #ifdef ELF_CORE_COPY_XFPREGS
1959 if (elf_core_copy_task_xfpregs(p, &t->xfpu)) {
1960 fill_note(&t->notes[2], "LINUX", ELF_CORE_XFPREG_TYPE,
1961 sizeof(t->xfpu), &t->xfpu);
1963 sz += notesize(&t->notes[2]);
1969 struct elf_note_info {
1970 struct memelfnote *notes;
1971 struct memelfnote *notes_files;
1972 struct elf_prstatus *prstatus; /* NT_PRSTATUS */
1973 struct elf_prpsinfo *psinfo; /* NT_PRPSINFO */
1974 struct list_head thread_list;
1975 elf_fpregset_t *fpu;
1976 #ifdef ELF_CORE_COPY_XFPREGS
1977 elf_fpxregset_t *xfpu;
1979 user_siginfo_t csigdata;
1980 int thread_status_size;
1984 static int elf_note_info_init(struct elf_note_info *info)
1986 memset(info, 0, sizeof(*info));
1987 INIT_LIST_HEAD(&info->thread_list);
1989 /* Allocate space for ELF notes */
1990 info->notes = kmalloc_array(8, sizeof(struct memelfnote), GFP_KERNEL);
1993 info->psinfo = kmalloc(sizeof(*info->psinfo), GFP_KERNEL);
1996 info->prstatus = kmalloc(sizeof(*info->prstatus), GFP_KERNEL);
1997 if (!info->prstatus)
1999 info->fpu = kmalloc(sizeof(*info->fpu), GFP_KERNEL);
2002 #ifdef ELF_CORE_COPY_XFPREGS
2003 info->xfpu = kmalloc(sizeof(*info->xfpu), GFP_KERNEL);
2010 static int fill_note_info(struct elfhdr *elf, int phdrs,
2011 struct elf_note_info *info,
2012 const kernel_siginfo_t *siginfo, struct pt_regs *regs)
2014 struct core_thread *ct;
2015 struct elf_thread_status *ets;
2017 if (!elf_note_info_init(info))
2020 for (ct = current->mm->core_state->dumper.next;
2021 ct; ct = ct->next) {
2022 ets = kzalloc(sizeof(*ets), GFP_KERNEL);
2026 ets->thread = ct->task;
2027 list_add(&ets->list, &info->thread_list);
2030 list_for_each_entry(ets, &info->thread_list, list) {
2033 sz = elf_dump_thread_status(siginfo->si_signo, ets);
2034 info->thread_status_size += sz;
2036 /* now collect the dump for the current */
2037 memset(info->prstatus, 0, sizeof(*info->prstatus));
2038 fill_prstatus(info->prstatus, current, siginfo->si_signo);
2039 elf_core_copy_regs(&info->prstatus->pr_reg, regs);
2042 fill_elf_header(elf, phdrs, ELF_ARCH, ELF_CORE_EFLAGS);
2045 * Set up the notes in similar form to SVR4 core dumps made
2046 * with info from their /proc.
2049 fill_note(info->notes + 0, "CORE", NT_PRSTATUS,
2050 sizeof(*info->prstatus), info->prstatus);
2051 fill_psinfo(info->psinfo, current->group_leader, current->mm);
2052 fill_note(info->notes + 1, "CORE", NT_PRPSINFO,
2053 sizeof(*info->psinfo), info->psinfo);
2055 fill_siginfo_note(info->notes + 2, &info->csigdata, siginfo);
2056 fill_auxv_note(info->notes + 3, current->mm);
2059 if (fill_files_note(info->notes + info->numnote) == 0) {
2060 info->notes_files = info->notes + info->numnote;
2064 /* Try to dump the FPU. */
2065 info->prstatus->pr_fpvalid = elf_core_copy_task_fpregs(current, regs,
2067 if (info->prstatus->pr_fpvalid)
2068 fill_note(info->notes + info->numnote++,
2069 "CORE", NT_PRFPREG, sizeof(*info->fpu), info->fpu);
2070 #ifdef ELF_CORE_COPY_XFPREGS
2071 if (elf_core_copy_task_xfpregs(current, info->xfpu))
2072 fill_note(info->notes + info->numnote++,
2073 "LINUX", ELF_CORE_XFPREG_TYPE,
2074 sizeof(*info->xfpu), info->xfpu);
2080 static size_t get_note_info_size(struct elf_note_info *info)
2085 for (i = 0; i < info->numnote; i++)
2086 sz += notesize(info->notes + i);
2088 sz += info->thread_status_size;
2093 static int write_note_info(struct elf_note_info *info,
2094 struct coredump_params *cprm)
2096 struct elf_thread_status *ets;
2099 for (i = 0; i < info->numnote; i++)
2100 if (!writenote(info->notes + i, cprm))
2103 /* write out the thread status notes section */
2104 list_for_each_entry(ets, &info->thread_list, list) {
2105 for (i = 0; i < ets->num_notes; i++)
2106 if (!writenote(&ets->notes[i], cprm))
2113 static void free_note_info(struct elf_note_info *info)
2115 while (!list_empty(&info->thread_list)) {
2116 struct list_head *tmp = info->thread_list.next;
2118 kfree(list_entry(tmp, struct elf_thread_status, list));
2121 /* Free data possibly allocated by fill_files_note(): */
2122 if (info->notes_files)
2123 kvfree(info->notes_files->data);
2125 kfree(info->prstatus);
2126 kfree(info->psinfo);
2129 #ifdef ELF_CORE_COPY_XFPREGS
2136 static struct vm_area_struct *first_vma(struct task_struct *tsk,
2137 struct vm_area_struct *gate_vma)
2139 struct vm_area_struct *ret = tsk->mm->mmap;
2146 * Helper function for iterating across a vma list. It ensures that the caller
2147 * will visit `gate_vma' prior to terminating the search.
2149 static struct vm_area_struct *next_vma(struct vm_area_struct *this_vma,
2150 struct vm_area_struct *gate_vma)
2152 struct vm_area_struct *ret;
2154 ret = this_vma->vm_next;
2157 if (this_vma == gate_vma)
2162 static void fill_extnum_info(struct elfhdr *elf, struct elf_shdr *shdr4extnum,
2163 elf_addr_t e_shoff, int segs)
2165 elf->e_shoff = e_shoff;
2166 elf->e_shentsize = sizeof(*shdr4extnum);
2168 elf->e_shstrndx = SHN_UNDEF;
2170 memset(shdr4extnum, 0, sizeof(*shdr4extnum));
2172 shdr4extnum->sh_type = SHT_NULL;
2173 shdr4extnum->sh_size = elf->e_shnum;
2174 shdr4extnum->sh_link = elf->e_shstrndx;
2175 shdr4extnum->sh_info = segs;
2181 * This is a two-pass process; first we find the offsets of the bits,
2182 * and then they are actually written out. If we run out of core limit
2185 static int elf_core_dump(struct coredump_params *cprm)
2190 size_t vma_data_size = 0;
2191 struct vm_area_struct *vma, *gate_vma;
2193 loff_t offset = 0, dataoff;
2194 struct elf_note_info info = { };
2195 struct elf_phdr *phdr4note = NULL;
2196 struct elf_shdr *shdr4extnum = NULL;
2199 elf_addr_t *vma_filesz = NULL;
2202 * We no longer stop all VM operations.
2204 * This is because those proceses that could possibly change map_count
2205 * or the mmap / vma pages are now blocked in do_exit on current
2206 * finishing this core dump.
2208 * Only ptrace can touch these memory addresses, but it doesn't change
2209 * the map_count or the pages allocated. So no possibility of crashing
2210 * exists while dumping the mm->vm_next areas to the core file.
2214 * The number of segs are recored into ELF header as 16bit value.
2215 * Please check DEFAULT_MAX_MAP_COUNT definition when you modify here.
2217 segs = current->mm->map_count;
2218 segs += elf_core_extra_phdrs();
2220 gate_vma = get_gate_vma(current->mm);
2221 if (gate_vma != NULL)
2224 /* for notes section */
2227 /* If segs > PN_XNUM(0xffff), then e_phnum overflows. To avoid
2228 * this, kernel supports extended numbering. Have a look at
2229 * include/linux/elf.h for further information. */
2230 e_phnum = segs > PN_XNUM ? PN_XNUM : segs;
2233 * Collect all the non-memory information about the process for the
2234 * notes. This also sets up the file header.
2236 if (!fill_note_info(&elf, e_phnum, &info, cprm->siginfo, cprm->regs))
2244 offset += sizeof(elf); /* Elf header */
2245 offset += segs * sizeof(struct elf_phdr); /* Program headers */
2247 /* Write notes phdr entry */
2249 size_t sz = get_note_info_size(&info);
2251 sz += elf_coredump_extra_notes_size();
2253 phdr4note = kmalloc(sizeof(*phdr4note), GFP_KERNEL);
2257 fill_elf_note_phdr(phdr4note, sz, offset);
2261 dataoff = offset = roundup(offset, ELF_EXEC_PAGESIZE);
2264 * Zero vma process will get ZERO_SIZE_PTR here.
2265 * Let coredump continue for register state at least.
2267 vma_filesz = kvmalloc(array_size(sizeof(*vma_filesz), (segs - 1)),
2272 for (i = 0, vma = first_vma(current, gate_vma); vma != NULL;
2273 vma = next_vma(vma, gate_vma)) {
2274 unsigned long dump_size;
2276 dump_size = vma_dump_size(vma, cprm->mm_flags);
2277 vma_filesz[i++] = dump_size;
2278 vma_data_size += dump_size;
2281 offset += vma_data_size;
2282 offset += elf_core_extra_data_size();
2285 if (e_phnum == PN_XNUM) {
2286 shdr4extnum = kmalloc(sizeof(*shdr4extnum), GFP_KERNEL);
2289 fill_extnum_info(&elf, shdr4extnum, e_shoff, segs);
2294 if (!dump_emit(cprm, &elf, sizeof(elf)))
2297 if (!dump_emit(cprm, phdr4note, sizeof(*phdr4note)))
2300 /* Write program headers for segments dump */
2301 for (i = 0, vma = first_vma(current, gate_vma); vma != NULL;
2302 vma = next_vma(vma, gate_vma)) {
2303 struct elf_phdr phdr;
2305 phdr.p_type = PT_LOAD;
2306 phdr.p_offset = offset;
2307 phdr.p_vaddr = vma->vm_start;
2309 phdr.p_filesz = vma_filesz[i++];
2310 phdr.p_memsz = vma->vm_end - vma->vm_start;
2311 offset += phdr.p_filesz;
2312 phdr.p_flags = vma->vm_flags & VM_READ ? PF_R : 0;
2313 if (vma->vm_flags & VM_WRITE)
2314 phdr.p_flags |= PF_W;
2315 if (vma->vm_flags & VM_EXEC)
2316 phdr.p_flags |= PF_X;
2317 phdr.p_align = ELF_EXEC_PAGESIZE;
2319 if (!dump_emit(cprm, &phdr, sizeof(phdr)))
2323 if (!elf_core_write_extra_phdrs(cprm, offset))
2326 /* write out the notes section */
2327 if (!write_note_info(&info, cprm))
2330 if (elf_coredump_extra_notes_write(cprm))
2334 if (!dump_skip(cprm, dataoff - cprm->pos))
2337 for (i = 0, vma = first_vma(current, gate_vma); vma != NULL;
2338 vma = next_vma(vma, gate_vma)) {
2342 end = vma->vm_start + vma_filesz[i++];
2344 for (addr = vma->vm_start; addr < end; addr += PAGE_SIZE) {
2348 page = get_dump_page(addr);
2350 void *kaddr = kmap(page);
2351 stop = !dump_emit(cprm, kaddr, PAGE_SIZE);
2355 stop = !dump_skip(cprm, PAGE_SIZE);
2360 dump_truncate(cprm);
2362 if (!elf_core_write_extra_data(cprm))
2365 if (e_phnum == PN_XNUM) {
2366 if (!dump_emit(cprm, shdr4extnum, sizeof(*shdr4extnum)))
2374 free_note_info(&info);
2381 #endif /* CONFIG_ELF_CORE */
2383 static int __init init_elf_binfmt(void)
2385 register_binfmt(&elf_format);
2389 static void __exit exit_elf_binfmt(void)
2391 /* Remove the COFF and ELF loaders. */
2392 unregister_binfmt(&elf_format);
2395 core_initcall(init_elf_binfmt);
2396 module_exit(exit_elf_binfmt);
2397 MODULE_LICENSE("GPL");