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);
861 install_exec_creds(bprm);
863 /* Do this so that we can load the interpreter, if need be. We will
864 change some of these later */
865 retval = setup_arg_pages(bprm, randomize_stack_top(STACK_TOP),
868 goto out_free_dentry;
878 /* Now we do a little grungy work by mmapping the ELF image into
879 the correct location in memory. */
880 for(i = 0, elf_ppnt = elf_phdata;
881 i < elf_ex->e_phnum; i++, elf_ppnt++) {
882 int elf_prot, elf_flags;
883 unsigned long k, vaddr;
884 unsigned long total_size = 0;
886 if (elf_ppnt->p_type != PT_LOAD)
889 if (unlikely (elf_brk > elf_bss)) {
892 /* There was a PT_LOAD segment with p_memsz > p_filesz
893 before this one. Map anonymous pages, if needed,
894 and clear the area. */
895 retval = set_brk(elf_bss + load_bias,
899 goto out_free_dentry;
900 nbyte = ELF_PAGEOFFSET(elf_bss);
902 nbyte = ELF_MIN_ALIGN - nbyte;
903 if (nbyte > elf_brk - elf_bss)
904 nbyte = elf_brk - elf_bss;
905 if (clear_user((void __user *)elf_bss +
908 * This bss-zeroing can fail if the ELF
909 * file specifies odd protections. So
910 * we don't check the return value
916 elf_prot = make_prot(elf_ppnt->p_flags);
918 elf_flags = MAP_PRIVATE | MAP_DENYWRITE | MAP_EXECUTABLE;
920 vaddr = elf_ppnt->p_vaddr;
922 * If we are loading ET_EXEC or we have already performed
923 * the ET_DYN load_addr calculations, proceed normally.
925 if (elf_ex->e_type == ET_EXEC || load_addr_set) {
926 elf_flags |= MAP_FIXED;
927 } else if (elf_ex->e_type == ET_DYN) {
929 * This logic is run once for the first LOAD Program
930 * Header for ET_DYN binaries to calculate the
931 * randomization (load_bias) for all the LOAD
932 * Program Headers, and to calculate the entire
933 * size of the ELF mapping (total_size). (Note that
934 * load_addr_set is set to true later once the
935 * initial mapping is performed.)
937 * There are effectively two types of ET_DYN
938 * binaries: programs (i.e. PIE: ET_DYN with INTERP)
939 * and loaders (ET_DYN without INTERP, since they
940 * _are_ the ELF interpreter). The loaders must
941 * be loaded away from programs since the program
942 * may otherwise collide with the loader (especially
943 * for ET_EXEC which does not have a randomized
944 * position). For example to handle invocations of
945 * "./ld.so someprog" to test out a new version of
946 * the loader, the subsequent program that the
947 * loader loads must avoid the loader itself, so
948 * they cannot share the same load range. Sufficient
949 * room for the brk must be allocated with the
950 * loader as well, since brk must be available with
953 * Therefore, programs are loaded offset from
954 * ELF_ET_DYN_BASE and loaders are loaded into the
955 * independently randomized mmap region (0 load_bias
956 * without MAP_FIXED).
959 load_bias = ELF_ET_DYN_BASE;
960 if (current->flags & PF_RANDOMIZE)
961 load_bias += arch_mmap_rnd();
962 elf_flags |= MAP_FIXED;
967 * Since load_bias is used for all subsequent loading
968 * calculations, we must lower it by the first vaddr
969 * so that the remaining calculations based on the
970 * ELF vaddrs will be correctly offset. The result
971 * is then page aligned.
973 load_bias = ELF_PAGESTART(load_bias - vaddr);
975 total_size = total_mapping_size(elf_phdata,
979 goto out_free_dentry;
983 error = elf_map(bprm->file, load_bias + vaddr, elf_ppnt,
984 elf_prot, elf_flags, total_size);
985 if (BAD_ADDR(error)) {
986 retval = IS_ERR((void *)error) ?
987 PTR_ERR((void*)error) : -EINVAL;
988 goto out_free_dentry;
991 if (!load_addr_set) {
993 load_addr = (elf_ppnt->p_vaddr - elf_ppnt->p_offset);
994 if (elf_ex->e_type == ET_DYN) {
996 ELF_PAGESTART(load_bias + vaddr);
997 load_addr += load_bias;
998 reloc_func_desc = load_bias;
1001 k = elf_ppnt->p_vaddr;
1002 if ((elf_ppnt->p_flags & PF_X) && k < start_code)
1008 * Check to see if the section's size will overflow the
1009 * allowed task size. Note that p_filesz must always be
1010 * <= p_memsz so it is only necessary to check p_memsz.
1012 if (BAD_ADDR(k) || elf_ppnt->p_filesz > elf_ppnt->p_memsz ||
1013 elf_ppnt->p_memsz > TASK_SIZE ||
1014 TASK_SIZE - elf_ppnt->p_memsz < k) {
1015 /* set_brk can never work. Avoid overflows. */
1017 goto out_free_dentry;
1020 k = elf_ppnt->p_vaddr + elf_ppnt->p_filesz;
1024 if ((elf_ppnt->p_flags & PF_X) && end_code < k)
1028 k = elf_ppnt->p_vaddr + elf_ppnt->p_memsz;
1030 bss_prot = elf_prot;
1035 e_entry = elf_ex->e_entry + load_bias;
1036 elf_bss += load_bias;
1037 elf_brk += load_bias;
1038 start_code += load_bias;
1039 end_code += load_bias;
1040 start_data += load_bias;
1041 end_data += load_bias;
1043 /* Calling set_brk effectively mmaps the pages that we need
1044 * for the bss and break sections. We must do this before
1045 * mapping in the interpreter, to make sure it doesn't wind
1046 * up getting placed where the bss needs to go.
1048 retval = set_brk(elf_bss, elf_brk, bss_prot);
1050 goto out_free_dentry;
1051 if (likely(elf_bss != elf_brk) && unlikely(padzero(elf_bss))) {
1052 retval = -EFAULT; /* Nobody gets to see this, but.. */
1053 goto out_free_dentry;
1057 elf_entry = load_elf_interp(interp_elf_ex,
1059 load_bias, interp_elf_phdata);
1060 if (!IS_ERR((void *)elf_entry)) {
1062 * load_elf_interp() returns relocation
1065 interp_load_addr = elf_entry;
1066 elf_entry += interp_elf_ex->e_entry;
1068 if (BAD_ADDR(elf_entry)) {
1069 retval = IS_ERR((void *)elf_entry) ?
1070 (int)elf_entry : -EINVAL;
1071 goto out_free_dentry;
1073 reloc_func_desc = interp_load_addr;
1075 allow_write_access(interpreter);
1078 kfree(interp_elf_ex);
1079 kfree(interp_elf_phdata);
1081 elf_entry = e_entry;
1082 if (BAD_ADDR(elf_entry)) {
1084 goto out_free_dentry;
1090 set_binfmt(&elf_format);
1092 #ifdef ARCH_HAS_SETUP_ADDITIONAL_PAGES
1093 retval = arch_setup_additional_pages(bprm, !!interpreter);
1096 #endif /* ARCH_HAS_SETUP_ADDITIONAL_PAGES */
1098 retval = create_elf_tables(bprm, elf_ex,
1099 load_addr, interp_load_addr, e_entry);
1104 mm->end_code = end_code;
1105 mm->start_code = start_code;
1106 mm->start_data = start_data;
1107 mm->end_data = end_data;
1108 mm->start_stack = bprm->p;
1110 if ((current->flags & PF_RANDOMIZE) && (randomize_va_space > 1)) {
1112 * For architectures with ELF randomization, when executing
1113 * a loader directly (i.e. no interpreter listed in ELF
1114 * headers), move the brk area out of the mmap region
1115 * (since it grows up, and may collide early with the stack
1116 * growing down), and into the unused ELF_ET_DYN_BASE region.
1118 if (IS_ENABLED(CONFIG_ARCH_HAS_ELF_RANDOMIZE) &&
1119 elf_ex->e_type == ET_DYN && !interpreter) {
1120 mm->brk = mm->start_brk = ELF_ET_DYN_BASE;
1123 mm->brk = mm->start_brk = arch_randomize_brk(mm);
1124 #ifdef compat_brk_randomized
1125 current->brk_randomized = 1;
1129 if (current->personality & MMAP_PAGE_ZERO) {
1130 /* Why this, you ask??? Well SVr4 maps page 0 as read-only,
1131 and some applications "depend" upon this behavior.
1132 Since we do not have the power to recompile these, we
1133 emulate the SVr4 behavior. Sigh. */
1134 error = vm_mmap(NULL, 0, PAGE_SIZE, PROT_READ | PROT_EXEC,
1135 MAP_FIXED | MAP_PRIVATE, 0);
1138 regs = current_pt_regs();
1139 #ifdef ELF_PLAT_INIT
1141 * The ABI may specify that certain registers be set up in special
1142 * ways (on i386 %edx is the address of a DT_FINI function, for
1143 * example. In addition, it may also specify (eg, PowerPC64 ELF)
1144 * that the e_entry field is the address of the function descriptor
1145 * for the startup routine, rather than the address of the startup
1146 * routine itself. This macro performs whatever initialization to
1147 * the regs structure is required as well as any relocations to the
1148 * function descriptor entries when executing dynamically links apps.
1150 ELF_PLAT_INIT(regs, reloc_func_desc);
1153 finalize_exec(bprm);
1154 start_thread(regs, elf_entry, bprm->p);
1161 kfree(interp_elf_ex);
1162 kfree(interp_elf_phdata);
1163 allow_write_access(interpreter);
1171 #ifdef CONFIG_USELIB
1172 /* This is really simpleminded and specialized - we are loading an
1173 a.out library that is given an ELF header. */
1174 static int load_elf_library(struct file *file)
1176 struct elf_phdr *elf_phdata;
1177 struct elf_phdr *eppnt;
1178 unsigned long elf_bss, bss, len;
1179 int retval, error, i, j;
1180 struct elfhdr elf_ex;
1183 retval = elf_read(file, &elf_ex, sizeof(elf_ex), 0);
1187 if (memcmp(elf_ex.e_ident, ELFMAG, SELFMAG) != 0)
1190 /* First of all, some simple consistency checks */
1191 if (elf_ex.e_type != ET_EXEC || elf_ex.e_phnum > 2 ||
1192 !elf_check_arch(&elf_ex) || !file->f_op->mmap)
1194 if (elf_check_fdpic(&elf_ex))
1197 /* Now read in all of the header information */
1199 j = sizeof(struct elf_phdr) * elf_ex.e_phnum;
1200 /* j < ELF_MIN_ALIGN because elf_ex.e_phnum <= 2 */
1203 elf_phdata = kmalloc(j, GFP_KERNEL);
1209 retval = elf_read(file, eppnt, j, elf_ex.e_phoff);
1213 for (j = 0, i = 0; i<elf_ex.e_phnum; i++)
1214 if ((eppnt + i)->p_type == PT_LOAD)
1219 while (eppnt->p_type != PT_LOAD)
1222 /* Now use mmap to map the library into memory. */
1223 error = vm_mmap(file,
1224 ELF_PAGESTART(eppnt->p_vaddr),
1226 ELF_PAGEOFFSET(eppnt->p_vaddr)),
1227 PROT_READ | PROT_WRITE | PROT_EXEC,
1228 MAP_FIXED_NOREPLACE | MAP_PRIVATE | MAP_DENYWRITE,
1230 ELF_PAGEOFFSET(eppnt->p_vaddr)));
1231 if (error != ELF_PAGESTART(eppnt->p_vaddr))
1234 elf_bss = eppnt->p_vaddr + eppnt->p_filesz;
1235 if (padzero(elf_bss)) {
1240 len = ELF_PAGEALIGN(eppnt->p_filesz + eppnt->p_vaddr);
1241 bss = ELF_PAGEALIGN(eppnt->p_memsz + eppnt->p_vaddr);
1243 error = vm_brk(len, bss - len);
1254 #endif /* #ifdef CONFIG_USELIB */
1256 #ifdef CONFIG_ELF_CORE
1260 * Modelled on fs/exec.c:aout_core_dump()
1261 * Jeremy Fitzhardinge <jeremy@sw.oz.au>
1265 * The purpose of always_dump_vma() is to make sure that special kernel mappings
1266 * that are useful for post-mortem analysis are included in every core dump.
1267 * In that way we ensure that the core dump is fully interpretable later
1268 * without matching up the same kernel and hardware config to see what PC values
1269 * meant. These special mappings include - vDSO, vsyscall, and other
1270 * architecture specific mappings
1272 static bool always_dump_vma(struct vm_area_struct *vma)
1274 /* Any vsyscall mappings? */
1275 if (vma == get_gate_vma(vma->vm_mm))
1279 * Assume that all vmas with a .name op should always be dumped.
1280 * If this changes, a new vm_ops field can easily be added.
1282 if (vma->vm_ops && vma->vm_ops->name && vma->vm_ops->name(vma))
1286 * arch_vma_name() returns non-NULL for special architecture mappings,
1287 * such as vDSO sections.
1289 if (arch_vma_name(vma))
1296 * Decide what to dump of a segment, part, all or none.
1298 static unsigned long vma_dump_size(struct vm_area_struct *vma,
1299 unsigned long mm_flags)
1301 #define FILTER(type) (mm_flags & (1UL << MMF_DUMP_##type))
1303 /* always dump the vdso and vsyscall sections */
1304 if (always_dump_vma(vma))
1307 if (vma->vm_flags & VM_DONTDUMP)
1310 /* support for DAX */
1311 if (vma_is_dax(vma)) {
1312 if ((vma->vm_flags & VM_SHARED) && FILTER(DAX_SHARED))
1314 if (!(vma->vm_flags & VM_SHARED) && FILTER(DAX_PRIVATE))
1319 /* Hugetlb memory check */
1320 if (is_vm_hugetlb_page(vma)) {
1321 if ((vma->vm_flags & VM_SHARED) && FILTER(HUGETLB_SHARED))
1323 if (!(vma->vm_flags & VM_SHARED) && FILTER(HUGETLB_PRIVATE))
1328 /* Do not dump I/O mapped devices or special mappings */
1329 if (vma->vm_flags & VM_IO)
1332 /* By default, dump shared memory if mapped from an anonymous file. */
1333 if (vma->vm_flags & VM_SHARED) {
1334 if (file_inode(vma->vm_file)->i_nlink == 0 ?
1335 FILTER(ANON_SHARED) : FILTER(MAPPED_SHARED))
1340 /* Dump segments that have been written to. */
1341 if (vma->anon_vma && FILTER(ANON_PRIVATE))
1343 if (vma->vm_file == NULL)
1346 if (FILTER(MAPPED_PRIVATE))
1350 * If this looks like the beginning of a DSO or executable mapping,
1351 * check for an ELF header. If we find one, dump the first page to
1352 * aid in determining what was mapped here.
1354 if (FILTER(ELF_HEADERS) &&
1355 vma->vm_pgoff == 0 && (vma->vm_flags & VM_READ)) {
1356 u32 __user *header = (u32 __user *) vma->vm_start;
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;
1370 if (unlikely(get_user(word, header)))
1372 if (word == magic.cmp)
1381 return vma->vm_end - vma->vm_start;
1384 /* An ELF note in memory */
1389 unsigned int datasz;
1393 static int notesize(struct memelfnote *en)
1397 sz = sizeof(struct elf_note);
1398 sz += roundup(strlen(en->name) + 1, 4);
1399 sz += roundup(en->datasz, 4);
1404 static int writenote(struct memelfnote *men, struct coredump_params *cprm)
1407 en.n_namesz = strlen(men->name) + 1;
1408 en.n_descsz = men->datasz;
1409 en.n_type = men->type;
1411 return dump_emit(cprm, &en, sizeof(en)) &&
1412 dump_emit(cprm, men->name, en.n_namesz) && dump_align(cprm, 4) &&
1413 dump_emit(cprm, men->data, men->datasz) && dump_align(cprm, 4);
1416 static void fill_elf_header(struct elfhdr *elf, int segs,
1417 u16 machine, u32 flags)
1419 memset(elf, 0, sizeof(*elf));
1421 memcpy(elf->e_ident, ELFMAG, SELFMAG);
1422 elf->e_ident[EI_CLASS] = ELF_CLASS;
1423 elf->e_ident[EI_DATA] = ELF_DATA;
1424 elf->e_ident[EI_VERSION] = EV_CURRENT;
1425 elf->e_ident[EI_OSABI] = ELF_OSABI;
1427 elf->e_type = ET_CORE;
1428 elf->e_machine = machine;
1429 elf->e_version = EV_CURRENT;
1430 elf->e_phoff = sizeof(struct elfhdr);
1431 elf->e_flags = flags;
1432 elf->e_ehsize = sizeof(struct elfhdr);
1433 elf->e_phentsize = sizeof(struct elf_phdr);
1434 elf->e_phnum = segs;
1437 static void fill_elf_note_phdr(struct elf_phdr *phdr, int sz, loff_t offset)
1439 phdr->p_type = PT_NOTE;
1440 phdr->p_offset = offset;
1443 phdr->p_filesz = sz;
1449 static void fill_note(struct memelfnote *note, const char *name, int type,
1450 unsigned int sz, void *data)
1459 * fill up all the fields in prstatus from the given task struct, except
1460 * registers which need to be filled up separately.
1462 static void fill_prstatus(struct elf_prstatus *prstatus,
1463 struct task_struct *p, long signr)
1465 prstatus->pr_info.si_signo = prstatus->pr_cursig = signr;
1466 prstatus->pr_sigpend = p->pending.signal.sig[0];
1467 prstatus->pr_sighold = p->blocked.sig[0];
1469 prstatus->pr_ppid = task_pid_vnr(rcu_dereference(p->real_parent));
1471 prstatus->pr_pid = task_pid_vnr(p);
1472 prstatus->pr_pgrp = task_pgrp_vnr(p);
1473 prstatus->pr_sid = task_session_vnr(p);
1474 if (thread_group_leader(p)) {
1475 struct task_cputime cputime;
1478 * This is the record for the group leader. It shows the
1479 * group-wide total, not its individual thread total.
1481 thread_group_cputime(p, &cputime);
1482 prstatus->pr_utime = ns_to_kernel_old_timeval(cputime.utime);
1483 prstatus->pr_stime = ns_to_kernel_old_timeval(cputime.stime);
1487 task_cputime(p, &utime, &stime);
1488 prstatus->pr_utime = ns_to_kernel_old_timeval(utime);
1489 prstatus->pr_stime = ns_to_kernel_old_timeval(stime);
1492 prstatus->pr_cutime = ns_to_kernel_old_timeval(p->signal->cutime);
1493 prstatus->pr_cstime = ns_to_kernel_old_timeval(p->signal->cstime);
1496 static int fill_psinfo(struct elf_prpsinfo *psinfo, struct task_struct *p,
1497 struct mm_struct *mm)
1499 const struct cred *cred;
1500 unsigned int i, len;
1502 /* first copy the parameters from user space */
1503 memset(psinfo, 0, sizeof(struct elf_prpsinfo));
1505 len = mm->arg_end - mm->arg_start;
1506 if (len >= ELF_PRARGSZ)
1507 len = ELF_PRARGSZ-1;
1508 if (copy_from_user(&psinfo->pr_psargs,
1509 (const char __user *)mm->arg_start, len))
1511 for(i = 0; i < len; i++)
1512 if (psinfo->pr_psargs[i] == 0)
1513 psinfo->pr_psargs[i] = ' ';
1514 psinfo->pr_psargs[len] = 0;
1517 psinfo->pr_ppid = task_pid_vnr(rcu_dereference(p->real_parent));
1519 psinfo->pr_pid = task_pid_vnr(p);
1520 psinfo->pr_pgrp = task_pgrp_vnr(p);
1521 psinfo->pr_sid = task_session_vnr(p);
1523 i = p->state ? ffz(~p->state) + 1 : 0;
1524 psinfo->pr_state = i;
1525 psinfo->pr_sname = (i > 5) ? '.' : "RSDTZW"[i];
1526 psinfo->pr_zomb = psinfo->pr_sname == 'Z';
1527 psinfo->pr_nice = task_nice(p);
1528 psinfo->pr_flag = p->flags;
1530 cred = __task_cred(p);
1531 SET_UID(psinfo->pr_uid, from_kuid_munged(cred->user_ns, cred->uid));
1532 SET_GID(psinfo->pr_gid, from_kgid_munged(cred->user_ns, cred->gid));
1534 strncpy(psinfo->pr_fname, p->comm, sizeof(psinfo->pr_fname));
1539 static void fill_auxv_note(struct memelfnote *note, struct mm_struct *mm)
1541 elf_addr_t *auxv = (elf_addr_t *) mm->saved_auxv;
1545 while (auxv[i - 2] != AT_NULL);
1546 fill_note(note, "CORE", NT_AUXV, i * sizeof(elf_addr_t), auxv);
1549 static void fill_siginfo_note(struct memelfnote *note, user_siginfo_t *csigdata,
1550 const kernel_siginfo_t *siginfo)
1552 copy_siginfo_to_external(csigdata, siginfo);
1553 fill_note(note, "CORE", NT_SIGINFO, sizeof(*csigdata), csigdata);
1556 #define MAX_FILE_NOTE_SIZE (4*1024*1024)
1558 * Format of NT_FILE note:
1560 * long count -- how many files are mapped
1561 * long page_size -- units for file_ofs
1562 * array of [COUNT] elements of
1566 * followed by COUNT filenames in ASCII: "FILE1" NUL "FILE2" NUL...
1568 static int fill_files_note(struct memelfnote *note)
1570 struct mm_struct *mm = current->mm;
1571 struct vm_area_struct *vma;
1572 unsigned count, size, names_ofs, remaining, n;
1574 user_long_t *start_end_ofs;
1575 char *name_base, *name_curpos;
1577 /* *Estimated* file count and total data size needed */
1578 count = mm->map_count;
1579 if (count > UINT_MAX / 64)
1583 names_ofs = (2 + 3 * count) * sizeof(data[0]);
1585 if (size >= MAX_FILE_NOTE_SIZE) /* paranoia check */
1587 size = round_up(size, PAGE_SIZE);
1589 * "size" can be 0 here legitimately.
1590 * Let it ENOMEM and omit NT_FILE section which will be empty anyway.
1592 data = kvmalloc(size, GFP_KERNEL);
1593 if (ZERO_OR_NULL_PTR(data))
1596 start_end_ofs = data + 2;
1597 name_base = name_curpos = ((char *)data) + names_ofs;
1598 remaining = size - names_ofs;
1600 for (vma = mm->mmap; vma != NULL; vma = vma->vm_next) {
1602 const char *filename;
1604 file = vma->vm_file;
1607 filename = file_path(file, name_curpos, remaining);
1608 if (IS_ERR(filename)) {
1609 if (PTR_ERR(filename) == -ENAMETOOLONG) {
1611 size = size * 5 / 4;
1617 /* file_path() fills at the end, move name down */
1618 /* n = strlen(filename) + 1: */
1619 n = (name_curpos + remaining) - filename;
1620 remaining = filename - name_curpos;
1621 memmove(name_curpos, filename, n);
1624 *start_end_ofs++ = vma->vm_start;
1625 *start_end_ofs++ = vma->vm_end;
1626 *start_end_ofs++ = vma->vm_pgoff;
1630 /* Now we know exact count of files, can store it */
1632 data[1] = PAGE_SIZE;
1634 * Count usually is less than mm->map_count,
1635 * we need to move filenames down.
1637 n = mm->map_count - count;
1639 unsigned shift_bytes = n * 3 * sizeof(data[0]);
1640 memmove(name_base - shift_bytes, name_base,
1641 name_curpos - name_base);
1642 name_curpos -= shift_bytes;
1645 size = name_curpos - (char *)data;
1646 fill_note(note, "CORE", NT_FILE, size, data);
1650 #ifdef CORE_DUMP_USE_REGSET
1651 #include <linux/regset.h>
1653 struct elf_thread_core_info {
1654 struct elf_thread_core_info *next;
1655 struct task_struct *task;
1656 struct elf_prstatus prstatus;
1657 struct memelfnote notes[0];
1660 struct elf_note_info {
1661 struct elf_thread_core_info *thread;
1662 struct memelfnote psinfo;
1663 struct memelfnote signote;
1664 struct memelfnote auxv;
1665 struct memelfnote files;
1666 user_siginfo_t csigdata;
1672 * When a regset has a writeback hook, we call it on each thread before
1673 * dumping user memory. On register window machines, this makes sure the
1674 * user memory backing the register data is up to date before we read it.
1676 static void do_thread_regset_writeback(struct task_struct *task,
1677 const struct user_regset *regset)
1679 if (regset->writeback)
1680 regset->writeback(task, regset, 1);
1683 #ifndef PRSTATUS_SIZE
1684 #define PRSTATUS_SIZE(S, R) sizeof(S)
1687 #ifndef SET_PR_FPVALID
1688 #define SET_PR_FPVALID(S, V, R) ((S)->pr_fpvalid = (V))
1691 static int fill_thread_core_info(struct elf_thread_core_info *t,
1692 const struct user_regset_view *view,
1693 long signr, size_t *total)
1696 unsigned int regset0_size = regset_size(t->task, &view->regsets[0]);
1699 * NT_PRSTATUS is the one special case, because the regset data
1700 * goes into the pr_reg field inside the note contents, rather
1701 * than being the whole note contents. We fill the reset in here.
1702 * We assume that regset 0 is NT_PRSTATUS.
1704 fill_prstatus(&t->prstatus, t->task, signr);
1705 (void) view->regsets[0].get(t->task, &view->regsets[0], 0, regset0_size,
1706 &t->prstatus.pr_reg, NULL);
1708 fill_note(&t->notes[0], "CORE", NT_PRSTATUS,
1709 PRSTATUS_SIZE(t->prstatus, regset0_size), &t->prstatus);
1710 *total += notesize(&t->notes[0]);
1712 do_thread_regset_writeback(t->task, &view->regsets[0]);
1715 * Each other regset might generate a note too. For each regset
1716 * that has no core_note_type or is inactive, we leave t->notes[i]
1717 * all zero and we'll know to skip writing it later.
1719 for (i = 1; i < view->n; ++i) {
1720 const struct user_regset *regset = &view->regsets[i];
1721 do_thread_regset_writeback(t->task, regset);
1722 if (regset->core_note_type && regset->get &&
1723 (!regset->active || regset->active(t->task, regset) > 0)) {
1725 size_t size = regset_size(t->task, regset);
1726 void *data = kmalloc(size, GFP_KERNEL);
1727 if (unlikely(!data))
1729 ret = regset->get(t->task, regset,
1730 0, size, data, NULL);
1734 if (regset->core_note_type != NT_PRFPREG)
1735 fill_note(&t->notes[i], "LINUX",
1736 regset->core_note_type,
1739 SET_PR_FPVALID(&t->prstatus,
1741 fill_note(&t->notes[i], "CORE",
1742 NT_PRFPREG, size, data);
1744 *total += notesize(&t->notes[i]);
1752 static int fill_note_info(struct elfhdr *elf, int phdrs,
1753 struct elf_note_info *info,
1754 const kernel_siginfo_t *siginfo, struct pt_regs *regs)
1756 struct task_struct *dump_task = current;
1757 const struct user_regset_view *view = task_user_regset_view(dump_task);
1758 struct elf_thread_core_info *t;
1759 struct elf_prpsinfo *psinfo;
1760 struct core_thread *ct;
1764 info->thread = NULL;
1766 psinfo = kmalloc(sizeof(*psinfo), GFP_KERNEL);
1767 if (psinfo == NULL) {
1768 info->psinfo.data = NULL; /* So we don't free this wrongly */
1772 fill_note(&info->psinfo, "CORE", NT_PRPSINFO, sizeof(*psinfo), psinfo);
1775 * Figure out how many notes we're going to need for each thread.
1777 info->thread_notes = 0;
1778 for (i = 0; i < view->n; ++i)
1779 if (view->regsets[i].core_note_type != 0)
1780 ++info->thread_notes;
1783 * Sanity check. We rely on regset 0 being in NT_PRSTATUS,
1784 * since it is our one special case.
1786 if (unlikely(info->thread_notes == 0) ||
1787 unlikely(view->regsets[0].core_note_type != NT_PRSTATUS)) {
1793 * Initialize the ELF file header.
1795 fill_elf_header(elf, phdrs,
1796 view->e_machine, view->e_flags);
1799 * Allocate a structure for each thread.
1801 for (ct = &dump_task->mm->core_state->dumper; ct; ct = ct->next) {
1802 t = kzalloc(offsetof(struct elf_thread_core_info,
1803 notes[info->thread_notes]),
1809 if (ct->task == dump_task || !info->thread) {
1810 t->next = info->thread;
1814 * Make sure to keep the original task at
1815 * the head of the list.
1817 t->next = info->thread->next;
1818 info->thread->next = t;
1823 * Now fill in each thread's information.
1825 for (t = info->thread; t != NULL; t = t->next)
1826 if (!fill_thread_core_info(t, view, siginfo->si_signo, &info->size))
1830 * Fill in the two process-wide notes.
1832 fill_psinfo(psinfo, dump_task->group_leader, dump_task->mm);
1833 info->size += notesize(&info->psinfo);
1835 fill_siginfo_note(&info->signote, &info->csigdata, siginfo);
1836 info->size += notesize(&info->signote);
1838 fill_auxv_note(&info->auxv, current->mm);
1839 info->size += notesize(&info->auxv);
1841 if (fill_files_note(&info->files) == 0)
1842 info->size += notesize(&info->files);
1847 static size_t get_note_info_size(struct elf_note_info *info)
1853 * Write all the notes for each thread. When writing the first thread, the
1854 * process-wide notes are interleaved after the first thread-specific note.
1856 static int write_note_info(struct elf_note_info *info,
1857 struct coredump_params *cprm)
1860 struct elf_thread_core_info *t = info->thread;
1865 if (!writenote(&t->notes[0], cprm))
1868 if (first && !writenote(&info->psinfo, cprm))
1870 if (first && !writenote(&info->signote, cprm))
1872 if (first && !writenote(&info->auxv, cprm))
1874 if (first && info->files.data &&
1875 !writenote(&info->files, cprm))
1878 for (i = 1; i < info->thread_notes; ++i)
1879 if (t->notes[i].data &&
1880 !writenote(&t->notes[i], cprm))
1890 static void free_note_info(struct elf_note_info *info)
1892 struct elf_thread_core_info *threads = info->thread;
1895 struct elf_thread_core_info *t = threads;
1897 WARN_ON(t->notes[0].data && t->notes[0].data != &t->prstatus);
1898 for (i = 1; i < info->thread_notes; ++i)
1899 kfree(t->notes[i].data);
1902 kfree(info->psinfo.data);
1903 kvfree(info->files.data);
1908 /* Here is the structure in which status of each thread is captured. */
1909 struct elf_thread_status
1911 struct list_head list;
1912 struct elf_prstatus prstatus; /* NT_PRSTATUS */
1913 elf_fpregset_t fpu; /* NT_PRFPREG */
1914 struct task_struct *thread;
1915 #ifdef ELF_CORE_COPY_XFPREGS
1916 elf_fpxregset_t xfpu; /* ELF_CORE_XFPREG_TYPE */
1918 struct memelfnote notes[3];
1923 * In order to add the specific thread information for the elf file format,
1924 * we need to keep a linked list of every threads pr_status and then create
1925 * a single section for them in the final core file.
1927 static int elf_dump_thread_status(long signr, struct elf_thread_status *t)
1930 struct task_struct *p = t->thread;
1933 fill_prstatus(&t->prstatus, p, signr);
1934 elf_core_copy_task_regs(p, &t->prstatus.pr_reg);
1936 fill_note(&t->notes[0], "CORE", NT_PRSTATUS, sizeof(t->prstatus),
1939 sz += notesize(&t->notes[0]);
1941 if ((t->prstatus.pr_fpvalid = elf_core_copy_task_fpregs(p, NULL,
1943 fill_note(&t->notes[1], "CORE", NT_PRFPREG, sizeof(t->fpu),
1946 sz += notesize(&t->notes[1]);
1949 #ifdef ELF_CORE_COPY_XFPREGS
1950 if (elf_core_copy_task_xfpregs(p, &t->xfpu)) {
1951 fill_note(&t->notes[2], "LINUX", ELF_CORE_XFPREG_TYPE,
1952 sizeof(t->xfpu), &t->xfpu);
1954 sz += notesize(&t->notes[2]);
1960 struct elf_note_info {
1961 struct memelfnote *notes;
1962 struct memelfnote *notes_files;
1963 struct elf_prstatus *prstatus; /* NT_PRSTATUS */
1964 struct elf_prpsinfo *psinfo; /* NT_PRPSINFO */
1965 struct list_head thread_list;
1966 elf_fpregset_t *fpu;
1967 #ifdef ELF_CORE_COPY_XFPREGS
1968 elf_fpxregset_t *xfpu;
1970 user_siginfo_t csigdata;
1971 int thread_status_size;
1975 static int elf_note_info_init(struct elf_note_info *info)
1977 memset(info, 0, sizeof(*info));
1978 INIT_LIST_HEAD(&info->thread_list);
1980 /* Allocate space for ELF notes */
1981 info->notes = kmalloc_array(8, sizeof(struct memelfnote), GFP_KERNEL);
1984 info->psinfo = kmalloc(sizeof(*info->psinfo), GFP_KERNEL);
1987 info->prstatus = kmalloc(sizeof(*info->prstatus), GFP_KERNEL);
1988 if (!info->prstatus)
1990 info->fpu = kmalloc(sizeof(*info->fpu), GFP_KERNEL);
1993 #ifdef ELF_CORE_COPY_XFPREGS
1994 info->xfpu = kmalloc(sizeof(*info->xfpu), GFP_KERNEL);
2001 static int fill_note_info(struct elfhdr *elf, int phdrs,
2002 struct elf_note_info *info,
2003 const kernel_siginfo_t *siginfo, struct pt_regs *regs)
2005 struct core_thread *ct;
2006 struct elf_thread_status *ets;
2008 if (!elf_note_info_init(info))
2011 for (ct = current->mm->core_state->dumper.next;
2012 ct; ct = ct->next) {
2013 ets = kzalloc(sizeof(*ets), GFP_KERNEL);
2017 ets->thread = ct->task;
2018 list_add(&ets->list, &info->thread_list);
2021 list_for_each_entry(ets, &info->thread_list, list) {
2024 sz = elf_dump_thread_status(siginfo->si_signo, ets);
2025 info->thread_status_size += sz;
2027 /* now collect the dump for the current */
2028 memset(info->prstatus, 0, sizeof(*info->prstatus));
2029 fill_prstatus(info->prstatus, current, siginfo->si_signo);
2030 elf_core_copy_regs(&info->prstatus->pr_reg, regs);
2033 fill_elf_header(elf, phdrs, ELF_ARCH, ELF_CORE_EFLAGS);
2036 * Set up the notes in similar form to SVR4 core dumps made
2037 * with info from their /proc.
2040 fill_note(info->notes + 0, "CORE", NT_PRSTATUS,
2041 sizeof(*info->prstatus), info->prstatus);
2042 fill_psinfo(info->psinfo, current->group_leader, current->mm);
2043 fill_note(info->notes + 1, "CORE", NT_PRPSINFO,
2044 sizeof(*info->psinfo), info->psinfo);
2046 fill_siginfo_note(info->notes + 2, &info->csigdata, siginfo);
2047 fill_auxv_note(info->notes + 3, current->mm);
2050 if (fill_files_note(info->notes + info->numnote) == 0) {
2051 info->notes_files = info->notes + info->numnote;
2055 /* Try to dump the FPU. */
2056 info->prstatus->pr_fpvalid = elf_core_copy_task_fpregs(current, regs,
2058 if (info->prstatus->pr_fpvalid)
2059 fill_note(info->notes + info->numnote++,
2060 "CORE", NT_PRFPREG, sizeof(*info->fpu), info->fpu);
2061 #ifdef ELF_CORE_COPY_XFPREGS
2062 if (elf_core_copy_task_xfpregs(current, info->xfpu))
2063 fill_note(info->notes + info->numnote++,
2064 "LINUX", ELF_CORE_XFPREG_TYPE,
2065 sizeof(*info->xfpu), info->xfpu);
2071 static size_t get_note_info_size(struct elf_note_info *info)
2076 for (i = 0; i < info->numnote; i++)
2077 sz += notesize(info->notes + i);
2079 sz += info->thread_status_size;
2084 static int write_note_info(struct elf_note_info *info,
2085 struct coredump_params *cprm)
2087 struct elf_thread_status *ets;
2090 for (i = 0; i < info->numnote; i++)
2091 if (!writenote(info->notes + i, cprm))
2094 /* write out the thread status notes section */
2095 list_for_each_entry(ets, &info->thread_list, list) {
2096 for (i = 0; i < ets->num_notes; i++)
2097 if (!writenote(&ets->notes[i], cprm))
2104 static void free_note_info(struct elf_note_info *info)
2106 while (!list_empty(&info->thread_list)) {
2107 struct list_head *tmp = info->thread_list.next;
2109 kfree(list_entry(tmp, struct elf_thread_status, list));
2112 /* Free data possibly allocated by fill_files_note(): */
2113 if (info->notes_files)
2114 kvfree(info->notes_files->data);
2116 kfree(info->prstatus);
2117 kfree(info->psinfo);
2120 #ifdef ELF_CORE_COPY_XFPREGS
2127 static struct vm_area_struct *first_vma(struct task_struct *tsk,
2128 struct vm_area_struct *gate_vma)
2130 struct vm_area_struct *ret = tsk->mm->mmap;
2137 * Helper function for iterating across a vma list. It ensures that the caller
2138 * will visit `gate_vma' prior to terminating the search.
2140 static struct vm_area_struct *next_vma(struct vm_area_struct *this_vma,
2141 struct vm_area_struct *gate_vma)
2143 struct vm_area_struct *ret;
2145 ret = this_vma->vm_next;
2148 if (this_vma == gate_vma)
2153 static void fill_extnum_info(struct elfhdr *elf, struct elf_shdr *shdr4extnum,
2154 elf_addr_t e_shoff, int segs)
2156 elf->e_shoff = e_shoff;
2157 elf->e_shentsize = sizeof(*shdr4extnum);
2159 elf->e_shstrndx = SHN_UNDEF;
2161 memset(shdr4extnum, 0, sizeof(*shdr4extnum));
2163 shdr4extnum->sh_type = SHT_NULL;
2164 shdr4extnum->sh_size = elf->e_shnum;
2165 shdr4extnum->sh_link = elf->e_shstrndx;
2166 shdr4extnum->sh_info = segs;
2172 * This is a two-pass process; first we find the offsets of the bits,
2173 * and then they are actually written out. If we run out of core limit
2176 static int elf_core_dump(struct coredump_params *cprm)
2180 size_t vma_data_size = 0;
2181 struct vm_area_struct *vma, *gate_vma;
2183 loff_t offset = 0, dataoff;
2184 struct elf_note_info info = { };
2185 struct elf_phdr *phdr4note = NULL;
2186 struct elf_shdr *shdr4extnum = NULL;
2189 elf_addr_t *vma_filesz = NULL;
2192 * We no longer stop all VM operations.
2194 * This is because those proceses that could possibly change map_count
2195 * or the mmap / vma pages are now blocked in do_exit on current
2196 * finishing this core dump.
2198 * Only ptrace can touch these memory addresses, but it doesn't change
2199 * the map_count or the pages allocated. So no possibility of crashing
2200 * exists while dumping the mm->vm_next areas to the core file.
2204 * The number of segs are recored into ELF header as 16bit value.
2205 * Please check DEFAULT_MAX_MAP_COUNT definition when you modify here.
2207 segs = current->mm->map_count;
2208 segs += elf_core_extra_phdrs();
2210 gate_vma = get_gate_vma(current->mm);
2211 if (gate_vma != NULL)
2214 /* for notes section */
2217 /* If segs > PN_XNUM(0xffff), then e_phnum overflows. To avoid
2218 * this, kernel supports extended numbering. Have a look at
2219 * include/linux/elf.h for further information. */
2220 e_phnum = segs > PN_XNUM ? PN_XNUM : segs;
2223 * Collect all the non-memory information about the process for the
2224 * notes. This also sets up the file header.
2226 if (!fill_note_info(&elf, e_phnum, &info, cprm->siginfo, cprm->regs))
2231 offset += sizeof(elf); /* Elf header */
2232 offset += segs * sizeof(struct elf_phdr); /* Program headers */
2234 /* Write notes phdr entry */
2236 size_t sz = get_note_info_size(&info);
2238 sz += elf_coredump_extra_notes_size();
2240 phdr4note = kmalloc(sizeof(*phdr4note), GFP_KERNEL);
2244 fill_elf_note_phdr(phdr4note, sz, offset);
2248 dataoff = offset = roundup(offset, ELF_EXEC_PAGESIZE);
2251 * Zero vma process will get ZERO_SIZE_PTR here.
2252 * Let coredump continue for register state at least.
2254 vma_filesz = kvmalloc(array_size(sizeof(*vma_filesz), (segs - 1)),
2259 for (i = 0, vma = first_vma(current, gate_vma); vma != NULL;
2260 vma = next_vma(vma, gate_vma)) {
2261 unsigned long dump_size;
2263 dump_size = vma_dump_size(vma, cprm->mm_flags);
2264 vma_filesz[i++] = dump_size;
2265 vma_data_size += dump_size;
2268 offset += vma_data_size;
2269 offset += elf_core_extra_data_size();
2272 if (e_phnum == PN_XNUM) {
2273 shdr4extnum = kmalloc(sizeof(*shdr4extnum), GFP_KERNEL);
2276 fill_extnum_info(&elf, shdr4extnum, e_shoff, segs);
2281 if (!dump_emit(cprm, &elf, sizeof(elf)))
2284 if (!dump_emit(cprm, phdr4note, sizeof(*phdr4note)))
2287 /* Write program headers for segments dump */
2288 for (i = 0, vma = first_vma(current, gate_vma); vma != NULL;
2289 vma = next_vma(vma, gate_vma)) {
2290 struct elf_phdr phdr;
2292 phdr.p_type = PT_LOAD;
2293 phdr.p_offset = offset;
2294 phdr.p_vaddr = vma->vm_start;
2296 phdr.p_filesz = vma_filesz[i++];
2297 phdr.p_memsz = vma->vm_end - vma->vm_start;
2298 offset += phdr.p_filesz;
2299 phdr.p_flags = vma->vm_flags & VM_READ ? PF_R : 0;
2300 if (vma->vm_flags & VM_WRITE)
2301 phdr.p_flags |= PF_W;
2302 if (vma->vm_flags & VM_EXEC)
2303 phdr.p_flags |= PF_X;
2304 phdr.p_align = ELF_EXEC_PAGESIZE;
2306 if (!dump_emit(cprm, &phdr, sizeof(phdr)))
2310 if (!elf_core_write_extra_phdrs(cprm, offset))
2313 /* write out the notes section */
2314 if (!write_note_info(&info, cprm))
2317 if (elf_coredump_extra_notes_write(cprm))
2321 if (!dump_skip(cprm, dataoff - cprm->pos))
2324 for (i = 0, vma = first_vma(current, gate_vma); vma != NULL;
2325 vma = next_vma(vma, gate_vma)) {
2329 end = vma->vm_start + vma_filesz[i++];
2331 for (addr = vma->vm_start; addr < end; addr += PAGE_SIZE) {
2335 page = get_dump_page(addr);
2337 void *kaddr = kmap(page);
2338 stop = !dump_emit(cprm, kaddr, PAGE_SIZE);
2342 stop = !dump_skip(cprm, PAGE_SIZE);
2347 dump_truncate(cprm);
2349 if (!elf_core_write_extra_data(cprm))
2352 if (e_phnum == PN_XNUM) {
2353 if (!dump_emit(cprm, shdr4extnum, sizeof(*shdr4extnum)))
2358 free_note_info(&info);
2365 #endif /* CONFIG_ELF_CORE */
2367 static int __init init_elf_binfmt(void)
2369 register_binfmt(&elf_format);
2373 static void __exit exit_elf_binfmt(void)
2375 /* Remove the COFF and ELF loaders. */
2376 unregister_binfmt(&elf_format);
2379 core_initcall(init_elf_binfmt);
2380 module_exit(exit_elf_binfmt);
2381 MODULE_LICENSE("GPL");