* linux/fs/binfmt_elf.c
*
* These are the functions used to load ELF format executables as used
* on SVr4 machines. Information on the format may be found in the book
* "UNIX SYSTEM V RELEASE 4 Programmers Guide: Ansi C and Programming Support
* Tools".
*
* Copyright 1993, 1994: Eric Youngdale (ericy@cais.com).
*/
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/fs.h>
#include <linux/log2.h>
#include <linux/mm.h>
#include <linux/mman.h>
#include <linux/errno.h>
#include <linux/signal.h>
#include <linux/binfmts.h>
#include <linux/string.h>
#include <linux/file.h>
#include <linux/slab.h>
#include <linux/personality.h>
#include <linux/elfcore.h>
#include <linux/init.h>
#include <linux/highuid.h>
#include <linux/compiler.h>
#include <linux/highmem.h>
#include <linux/hugetlb.h>
#include <linux/pagemap.h>
#include <linux/vmalloc.h>
#include <linux/security.h>
#include <linux/random.h>
#include <linux/elf.h>
#include <linux/elf-randomize.h>
#include <linux/utsname.h>
#include <linux/coredump.h>
#include <linux/sched.h>
#include <linux/sched/coredump.h>
#include <linux/sched/task_stack.h>
#include <linux/sched/cputime.h>
#include <linux/sizes.h>
#include <linux/types.h>
#include <linux/cred.h>
#include <linux/dax.h>
#include <linux/uaccess.h>
#include <asm/param.h>
#include <asm/page.h>
#ifndef ELF_COMPAT
#define ELF_COMPAT 0
#endif
#ifndef user_long_t
#define user_long_t long
#endif
#ifndef user_siginfo_t
#define user_siginfo_t siginfo_t
#endif
#ifndef elf_check_fdpic
#define elf_check_fdpic(ex) false
#endif
static int load_elf_binary(struct linux_binprm *bprm);
#ifdef CONFIG_USELIB
static int load_elf_library(struct file *);
#else
#define load_elf_library NULL
#endif
* If we don't support core dumping, then supply a NULL so we
* don't even try.
*/
#ifdef CONFIG_ELF_CORE
static int elf_core_dump(struct coredump_params *cprm);
#else
#define elf_core_dump NULL
#endif
#if ELF_EXEC_PAGESIZE > PAGE_SIZE
#define ELF_MIN_ALIGN ELF_EXEC_PAGESIZE
#else
#define ELF_MIN_ALIGN PAGE_SIZE
#endif
#ifndef ELF_CORE_EFLAGS
#define ELF_CORE_EFLAGS 0
#endif
#define ELF_PAGESTART(_v) ((_v) & ~(unsigned long)(ELF_MIN_ALIGN-1))
#define ELF_PAGEOFFSET(_v) ((_v) & (ELF_MIN_ALIGN-1))
#define ELF_PAGEALIGN(_v) (((_v) + ELF_MIN_ALIGN - 1) & ~(ELF_MIN_ALIGN - 1))
static struct linux_binfmt elf_format = {
.module = THIS_MODULE,
.load_binary = load_elf_binary,
.load_shlib = load_elf_library,
.core_dump = elf_core_dump,
.min_coredump = ELF_EXEC_PAGESIZE,
};
#define BAD_ADDR(x) (unlikely((unsigned long)(x) >= TASK_SIZE))
static int set_brk(unsigned long start, unsigned long end, int prot)
{
start = ELF_PAGEALIGN(start);
end = ELF_PAGEALIGN(end);
if (end > start) {
* Map the last of the bss segment.
* If the header is requesting these pages to be
* executable, honour that (ppc32 needs this).
*/
int error = vm_brk_flags(start, end - start,
prot & PROT_EXEC ? VM_EXEC : 0);
if (error)
return error;
}
current->mm->start_brk = current->mm->brk = end;
return 0;
}
after the data section (i.e. bss). This would
contain the junk from the file that should not
be in memory
*/
static int padzero(unsigned long elf_bss)
{
unsigned long nbyte;
nbyte = ELF_PAGEOFFSET(elf_bss);
if (nbyte) {
nbyte = ELF_MIN_ALIGN - nbyte;
if (clear_user((void __user *) elf_bss, nbyte))
return -EFAULT;
}
return 0;
}
#ifdef CONFIG_STACK_GROWSUP
#define STACK_ADD(sp, items) ((elf_addr_t __user *)(sp) + (items))
#define STACK_ROUND(sp, items) \
((15 + (unsigned long) ((sp) + (items))) &~ 15UL)
#define STACK_ALLOC(sp, len) ({ \
elf_addr_t __user *old_sp = (elf_addr_t __user *)sp; sp += len; \
old_sp; })
#else
#define STACK_ADD(sp, items) ((elf_addr_t __user *)(sp) - (items))
#define STACK_ROUND(sp, items) \
(((unsigned long) (sp - items)) &~ 15UL)
#define STACK_ALLOC(sp, len) ({ sp -= len ; sp; })
#endif
#ifndef ELF_BASE_PLATFORM
* AT_BASE_PLATFORM indicates the "real" hardware/microarchitecture.
* If the arch defines ELF_BASE_PLATFORM (in asm/elf.h), the value
* will be copied to the user stack in the same manner as AT_PLATFORM.
*/
#define ELF_BASE_PLATFORM NULL
#endif
static int
create_elf_tables(struct linux_binprm *bprm, const struct elfhdr *exec,
unsigned long interp_load_addr,
unsigned long e_entry, unsigned long phdr_addr)
{
struct mm_struct *mm = current->mm;
unsigned long p = bprm->p;
int argc = bprm->argc;
int envc = bprm->envc;
elf_addr_t __user *sp;
elf_addr_t __user *u_platform;
elf_addr_t __user *u_base_platform;
elf_addr_t __user *u_rand_bytes;
const char *k_platform = ELF_PLATFORM;
const char *k_base_platform = ELF_BASE_PLATFORM;
unsigned char k_rand_bytes[16];
int items;
elf_addr_t *elf_info;
int ei_index;
const struct cred *cred = current_cred();
struct vm_area_struct *vma;
* In some cases (e.g. Hyper-Threading), we want to avoid L1
* evictions by the processes running on the same package. One
* thing we can do is to shuffle the initial stack for them.
*/
p = arch_align_stack(p);
* If this architecture has a platform capability string, copy it
* to userspace. In some cases (Sparc), this info is impossible
* for userspace to get any other way, in others (i386) it is
* merely difficult.
*/
u_platform = NULL;
if (k_platform) {
size_t len = strlen(k_platform) + 1;
u_platform = (elf_addr_t __user *)STACK_ALLOC(p, len);
if (copy_to_user(u_platform, k_platform, len))
return -EFAULT;
}
* If this architecture has a "base" platform capability
* string, copy it to userspace.
*/
u_base_platform = NULL;
if (k_base_platform) {
size_t len = strlen(k_base_platform) + 1;
u_base_platform = (elf_addr_t __user *)STACK_ALLOC(p, len);
if (copy_to_user(u_base_platform, k_base_platform, len))
return -EFAULT;
}
* Generate 16 random bytes for userspace PRNG seeding.
*/
get_random_bytes(k_rand_bytes, sizeof(k_rand_bytes));
u_rand_bytes = (elf_addr_t __user *)
STACK_ALLOC(p, sizeof(k_rand_bytes));
if (copy_to_user(u_rand_bytes, k_rand_bytes, sizeof(k_rand_bytes)))
return -EFAULT;
elf_info = (elf_addr_t *)mm->saved_auxv;
#define NEW_AUX_ENT(id, val) \
do { \
*elf_info++ = id; \
*elf_info++ = val; \
} while (0)
#ifdef ARCH_DLINFO
* ARCH_DLINFO must come first so PPC can do its special alignment of
* AUXV.
* update AT_VECTOR_SIZE_ARCH if the number of NEW_AUX_ENT() in
* ARCH_DLINFO changes
*/
ARCH_DLINFO;
#endif
NEW_AUX_ENT(AT_HWCAP, ELF_HWCAP);
NEW_AUX_ENT(AT_PAGESZ, ELF_EXEC_PAGESIZE);
NEW_AUX_ENT(AT_CLKTCK, CLOCKS_PER_SEC);
NEW_AUX_ENT(AT_PHDR, phdr_addr);
NEW_AUX_ENT(AT_PHENT, sizeof(struct elf_phdr));
NEW_AUX_ENT(AT_PHNUM, exec->e_phnum);
NEW_AUX_ENT(AT_BASE, interp_load_addr);
NEW_AUX_ENT(AT_FLAGS, 0);
NEW_AUX_ENT(AT_ENTRY, e_entry);
NEW_AUX_ENT(AT_UID, from_kuid_munged(cred->user_ns, cred->uid));
NEW_AUX_ENT(AT_EUID, from_kuid_munged(cred->user_ns, cred->euid));
NEW_AUX_ENT(AT_GID, from_kgid_munged(cred->user_ns, cred->gid));
NEW_AUX_ENT(AT_EGID, from_kgid_munged(cred->user_ns, cred->egid));
NEW_AUX_ENT(AT_SECURE, bprm->secureexec);
NEW_AUX_ENT(AT_RANDOM, (elf_addr_t)(unsigned long)u_rand_bytes);
#ifdef ELF_HWCAP2
NEW_AUX_ENT(AT_HWCAP2, ELF_HWCAP2);
#endif
NEW_AUX_ENT(AT_EXECFN, bprm->exec);
if (k_platform) {
NEW_AUX_ENT(AT_PLATFORM,
(elf_addr_t)(unsigned long)u_platform);
}
if (k_base_platform) {
NEW_AUX_ENT(AT_BASE_PLATFORM,
(elf_addr_t)(unsigned long)u_base_platform);
}
if (bprm->have_execfd) {
NEW_AUX_ENT(AT_EXECFD, bprm->execfd);
}
#undef NEW_AUX_ENT
memset(elf_info, 0, (char *)mm->saved_auxv +
sizeof(mm->saved_auxv) - (char *)elf_info);
elf_info += 2;
ei_index = elf_info - (elf_addr_t *)mm->saved_auxv;
sp = STACK_ADD(p, ei_index);
items = (argc + 1) + (envc + 1) + 1;
bprm->p = STACK_ROUND(sp, items);
#ifdef CONFIG_STACK_GROWSUP
sp = (elf_addr_t __user *)bprm->p - items - ei_index;
bprm->exec = (unsigned long)sp;
#else
sp = (elf_addr_t __user *)bprm->p;
#endif
* Grow the stack manually; some architectures have a limit on how
* far ahead a user-space access may be in order to grow the stack.
*/
if (mmap_read_lock_killable(mm))
return -EINTR;
vma = find_extend_vma(mm, bprm->p);
mmap_read_unlock(mm);
if (!vma)
return -EFAULT;
if (put_user(argc, sp++))
return -EFAULT;
p = mm->arg_end = mm->arg_start;
while (argc-- > 0) {
size_t len;
if (put_user((elf_addr_t)p, sp++))
return -EFAULT;
len = strnlen_user((void __user *)p, MAX_ARG_STRLEN);
if (!len || len > MAX_ARG_STRLEN)
return -EINVAL;
p += len;
}
if (put_user(0, sp++))
return -EFAULT;
mm->arg_end = p;
mm->env_end = mm->env_start = p;
while (envc-- > 0) {
size_t len;
if (put_user((elf_addr_t)p, sp++))
return -EFAULT;
len = strnlen_user((void __user *)p, MAX_ARG_STRLEN);
if (!len || len > MAX_ARG_STRLEN)
return -EINVAL;
p += len;
}
if (put_user(0, sp++))
return -EFAULT;
mm->env_end = p;
if (copy_to_user(sp, mm->saved_auxv, ei_index * sizeof(elf_addr_t)))
return -EFAULT;
return 0;
}
static unsigned long elf_map(struct file *filep, unsigned long addr,
const struct elf_phdr *eppnt, int prot, int type,
unsigned long total_size)
{
unsigned long map_addr;
unsigned long size = eppnt->p_filesz + ELF_PAGEOFFSET(eppnt->p_vaddr);
unsigned long off = eppnt->p_offset - ELF_PAGEOFFSET(eppnt->p_vaddr);
addr = ELF_PAGESTART(addr);
size = ELF_PAGEALIGN(size);
* segment with zero filesize is perfectly valid */
if (!size)
return addr;
* total_size is the size of the ELF (interpreter) image.
* The _first_ mmap needs to know the full size, otherwise
* randomization might put this image into an overlapping
* position with the ELF binary image. (since size < total_size)
* So we first map the 'big' image - and unmap the remainder at
* the end. (which unmap is needed for ELF images with holes.)
*/
if (total_size) {
total_size = ELF_PAGEALIGN(total_size);
map_addr = vm_mmap(filep, addr, total_size, prot, type, off);
if (!BAD_ADDR(map_addr))
vm_munmap(map_addr+size, total_size-size);
} else
map_addr = vm_mmap(filep, addr, size, prot, type, off);
if ((type & MAP_FIXED_NOREPLACE) &&
PTR_ERR((void *)map_addr) == -EEXIST)
pr_info("%d (%s): Uhuuh, elf segment at %px requested but the memory is mapped already\n",
task_pid_nr(current), current->comm, (void *)addr);
return(map_addr);
}
static unsigned long total_mapping_size(const struct elf_phdr *cmds, int nr)
{
int i, first_idx = -1, last_idx = -1;
for (i = 0; i < nr; i++) {
if (cmds[i].p_type == PT_LOAD) {
last_idx = i;
if (first_idx == -1)
first_idx = i;
}
}
if (first_idx == -1)
return 0;
return cmds[last_idx].p_vaddr + cmds[last_idx].p_memsz -
ELF_PAGESTART(cmds[first_idx].p_vaddr);
}
static int elf_read(struct file *file, void *buf, size_t len, loff_t pos)
{
ssize_t rv;
rv = kernel_read(file, buf, len, &pos);
if (unlikely(rv != len)) {
return (rv < 0) ? rv : -EIO;
}
return 0;
}
static unsigned long maximum_alignment(struct elf_phdr *cmds, int nr)
{
unsigned long alignment = 0;
int i;
for (i = 0; i < nr; i++) {
if (cmds[i].p_type == PT_LOAD) {
unsigned long p_align = cmds[i].p_align;
if (!is_power_of_2(p_align))
continue;
alignment = max(alignment, p_align);
}
}
return ELF_PAGEALIGN(alignment);
}
* load_elf_phdrs() - load ELF program headers
* @elf_ex: ELF header of the binary whose program headers should be loaded
* @elf_file: the opened ELF binary file
*
* Loads ELF program headers from the binary file elf_file, which has the ELF
* header pointed to by elf_ex, into a newly allocated array. The caller is
* responsible for freeing the allocated data. Returns an ERR_PTR upon failure.
*/
static struct elf_phdr *load_elf_phdrs(const struct elfhdr *elf_ex,
struct file *elf_file)
{
struct elf_phdr *elf_phdata = NULL;
int retval, err = -1;
unsigned int size;
* If the size of this structure has changed, then punt, since
* we will be doing the wrong thing.
*/
if (elf_ex->e_phentsize != sizeof(struct elf_phdr))
goto out;
size = sizeof(struct elf_phdr) * elf_ex->e_phnum;
if (size == 0 || size > 65536 || size > ELF_MIN_ALIGN)
goto out;
elf_phdata = kmalloc(size, GFP_KERNEL);
if (!elf_phdata)
goto out;
retval = elf_read(elf_file, elf_phdata, size, elf_ex->e_phoff);
if (retval < 0) {
err = retval;
goto out;
}
err = 0;
out:
if (err) {
kfree(elf_phdata);
elf_phdata = NULL;
}
return elf_phdata;
}
#ifndef CONFIG_ARCH_BINFMT_ELF_STATE
* struct arch_elf_state - arch-specific ELF loading state
*
* This structure is used to preserve architecture specific data during
* the loading of an ELF file, throughout the checking of architecture
* specific ELF headers & through to the point where the ELF load is
* known to be proceeding (ie. SET_PERSONALITY).
*
* This implementation is a dummy for architectures which require no
* specific state.
*/
struct arch_elf_state {
};
#define INIT_ARCH_ELF_STATE {}
* arch_elf_pt_proc() - check a PT_LOPROC..PT_HIPROC ELF program header
* @ehdr: The main ELF header
* @phdr: The program header to check
* @elf: The open ELF file
* @is_interp: True if the phdr is from the interpreter of the ELF being
* loaded, else false.
* @state: Architecture-specific state preserved throughout the process
* of loading the ELF.
*
* Inspects the program header phdr to validate its correctness and/or
* suitability for the system. Called once per ELF program header in the
* range PT_LOPROC to PT_HIPROC, for both the ELF being loaded and its
* interpreter.
*
* Return: Zero to proceed with the ELF load, non-zero to fail the ELF load
* with that return code.
*/
static inline int arch_elf_pt_proc(struct elfhdr *ehdr,
struct elf_phdr *phdr,
struct file *elf, bool is_interp,
struct arch_elf_state *state)
{
return 0;
}
* arch_check_elf() - check an ELF executable
* @ehdr: The main ELF header
* @has_interp: True if the ELF has an interpreter, else false.
* @interp_ehdr: The interpreter's ELF header
* @state: Architecture-specific state preserved throughout the process
* of loading the ELF.
*
* Provides a final opportunity for architecture code to reject the loading
* of the ELF & cause an exec syscall to return an error. This is called after
* all program headers to be checked by arch_elf_pt_proc have been.
*
* Return: Zero to proceed with the ELF load, non-zero to fail the ELF load
* with that return code.
*/
static inline int arch_check_elf(struct elfhdr *ehdr, bool has_interp,
struct elfhdr *interp_ehdr,
struct arch_elf_state *state)
{
return 0;
}
#endif
static inline int make_prot(u32 p_flags, struct arch_elf_state *arch_state,
bool has_interp, bool is_interp)
{
int prot = 0;
if (p_flags & PF_R)
prot |= PROT_READ;
if (p_flags & PF_W)
prot |= PROT_WRITE;
if (p_flags & PF_X)
prot |= PROT_EXEC;
return arch_elf_adjust_prot(prot, arch_state, has_interp, is_interp);
}
so we keep this separate. Technically the library read function
is only provided so that we can read a.out libraries that have
an ELF header */
static unsigned long load_elf_interp(struct elfhdr *interp_elf_ex,
struct file *interpreter,
unsigned long no_base, struct elf_phdr *interp_elf_phdata,
struct arch_elf_state *arch_state)
{
struct elf_phdr *eppnt;
unsigned long load_addr = 0;
int load_addr_set = 0;
unsigned long last_bss = 0, elf_bss = 0;
int bss_prot = 0;
unsigned long error = ~0UL;
unsigned long total_size;
int i;
if (interp_elf_ex->e_type != ET_EXEC &&
interp_elf_ex->e_type != ET_DYN)
goto out;
if (!elf_check_arch(interp_elf_ex) ||
elf_check_fdpic(interp_elf_ex))
goto out;
if (!interpreter->f_op->mmap)
goto out;
total_size = total_mapping_size(interp_elf_phdata,
interp_elf_ex->e_phnum);
if (!total_size) {
error = -EINVAL;
goto out;
}
eppnt = interp_elf_phdata;
for (i = 0; i < interp_elf_ex->e_phnum; i++, eppnt++) {
if (eppnt->p_type == PT_LOAD) {
int elf_type = MAP_PRIVATE | MAP_DENYWRITE;
int elf_prot = make_prot(eppnt->p_flags, arch_state,
true, true);
unsigned long vaddr = 0;
unsigned long k, map_addr;
vaddr = eppnt->p_vaddr;
if (interp_elf_ex->e_type == ET_EXEC || load_addr_set)
elf_type |= MAP_FIXED;
else if (no_base && interp_elf_ex->e_type == ET_DYN)
load_addr = -vaddr;
map_addr = elf_map(interpreter, load_addr + vaddr,
eppnt, elf_prot, elf_type, total_size);
total_size = 0;
error = map_addr;
if (BAD_ADDR(map_addr))
goto out;
if (!load_addr_set &&
interp_elf_ex->e_type == ET_DYN) {
load_addr = map_addr - ELF_PAGESTART(vaddr);
load_addr_set = 1;
}
* Check to see if the section's size will overflow the
* allowed task size. Note that p_filesz must always be
* <= p_memsize so it's only necessary to check p_memsz.
*/
k = load_addr + eppnt->p_vaddr;
if (BAD_ADDR(k) ||
eppnt->p_filesz > eppnt->p_memsz ||
eppnt->p_memsz > TASK_SIZE ||
TASK_SIZE - eppnt->p_memsz < k) {
error = -ENOMEM;
goto out;
}
* Find the end of the file mapping for this phdr, and
* keep track of the largest address we see for this.
*/
k = load_addr + eppnt->p_vaddr + eppnt->p_filesz;
if (k > elf_bss)
elf_bss = k;
* Do the same thing for the memory mapping - between
* elf_bss and last_bss is the bss section.
*/
k = load_addr + eppnt->p_vaddr + eppnt->p_memsz;
if (k > last_bss) {
last_bss = k;
bss_prot = elf_prot;
}
}
}
* Now fill out the bss section: first pad the last page from
* the file up to the page boundary, and zero it from elf_bss
* up to the end of the page.
*/
if (padzero(elf_bss)) {
error = -EFAULT;
goto out;
}
* Next, align both the file and mem bss up to the page size,
* since this is where elf_bss was just zeroed up to, and where
* last_bss will end after the vm_brk_flags() below.
*/
elf_bss = ELF_PAGEALIGN(elf_bss);
last_bss = ELF_PAGEALIGN(last_bss);
if (last_bss > elf_bss) {
error = vm_brk_flags(elf_bss, last_bss - elf_bss,
bss_prot & PROT_EXEC ? VM_EXEC : 0);
if (error)
goto out;
}
error = load_addr;
out:
return error;
}
* These are the functions used to load ELF style executables and shared
* libraries. There is no binary dependent code anywhere else.
*/
static int parse_elf_property(const char *data, size_t *off, size_t datasz,
struct arch_elf_state *arch,
bool have_prev_type, u32 *prev_type)
{
size_t o, step;
const struct gnu_property *pr;
int ret;
if (*off == datasz)
return -ENOENT;
if (WARN_ON_ONCE(*off > datasz || *off % ELF_GNU_PROPERTY_ALIGN))
return -EIO;
o = *off;
datasz -= *off;
if (datasz < sizeof(*pr))
return -ENOEXEC;
pr = (const struct gnu_property *)(data + o);
o += sizeof(*pr);
datasz -= sizeof(*pr);
if (pr->pr_datasz > datasz)
return -ENOEXEC;
WARN_ON_ONCE(o % ELF_GNU_PROPERTY_ALIGN);
step = round_up(pr->pr_datasz, ELF_GNU_PROPERTY_ALIGN);
if (step > datasz)
return -ENOEXEC;
if (have_prev_type && pr->pr_type <= *prev_type)
return -ENOEXEC;
*prev_type = pr->pr_type;
ret = arch_parse_elf_property(pr->pr_type, data + o,
pr->pr_datasz, ELF_COMPAT, arch);
if (ret)
return ret;
*off = o + step;
return 0;
}
#define NOTE_DATA_SZ SZ_1K
#define GNU_PROPERTY_TYPE_0_NAME "GNU"
#define NOTE_NAME_SZ (sizeof(GNU_PROPERTY_TYPE_0_NAME))
static int parse_elf_properties(struct file *f, const struct elf_phdr *phdr,
struct arch_elf_state *arch)
{
union {
struct elf_note nhdr;
char data[NOTE_DATA_SZ];
} note;
loff_t pos;
ssize_t n;
size_t off, datasz;
int ret;
bool have_prev_type;
u32 prev_type;
if (!IS_ENABLED(CONFIG_ARCH_USE_GNU_PROPERTY) || !phdr)
return 0;
if (WARN_ON_ONCE(phdr->p_type != PT_GNU_PROPERTY))
return -ENOEXEC;
if (phdr->p_filesz > sizeof(note))
return -ENOEXEC;
pos = phdr->p_offset;
n = kernel_read(f, ¬e, phdr->p_filesz, &pos);
BUILD_BUG_ON(sizeof(note) < sizeof(note.nhdr) + NOTE_NAME_SZ);
if (n < 0 || n < sizeof(note.nhdr) + NOTE_NAME_SZ)
return -EIO;
if (note.nhdr.n_type != NT_GNU_PROPERTY_TYPE_0 ||
note.nhdr.n_namesz != NOTE_NAME_SZ ||
strncmp(note.data + sizeof(note.nhdr),
GNU_PROPERTY_TYPE_0_NAME, n - sizeof(note.nhdr)))
return -ENOEXEC;
off = round_up(sizeof(note.nhdr) + NOTE_NAME_SZ,
ELF_GNU_PROPERTY_ALIGN);
if (off > n)
return -ENOEXEC;
if (note.nhdr.n_descsz > n - off)
return -ENOEXEC;
datasz = off + note.nhdr.n_descsz;
have_prev_type = false;
do {
ret = parse_elf_property(note.data, &off, datasz, arch,
have_prev_type, &prev_type);
have_prev_type = true;
} while (!ret);
return ret == -ENOENT ? 0 : ret;
}
static int load_elf_binary(struct linux_binprm *bprm)
{
struct file *interpreter = NULL;
unsigned long load_addr, load_bias = 0, phdr_addr = 0;
int load_addr_set = 0;
unsigned long error;
struct elf_phdr *elf_ppnt, *elf_phdata, *interp_elf_phdata = NULL;
struct elf_phdr *elf_property_phdata = NULL;
unsigned long elf_bss, elf_brk;
int bss_prot = 0;
int retval, i;
unsigned long elf_entry;
unsigned long e_entry;
unsigned long interp_load_addr = 0;
unsigned long start_code, end_code, start_data, end_data;
unsigned long reloc_func_desc __maybe_unused = 0;
int executable_stack = EXSTACK_DEFAULT;
struct elfhdr *elf_ex = (struct elfhdr *)bprm->buf;
struct elfhdr *interp_elf_ex = NULL;
struct arch_elf_state arch_state = INIT_ARCH_ELF_STATE;
struct mm_struct *mm;
struct pt_regs *regs;
const int snapshot_randomize_va_space = READ_ONCE(randomize_va_space);
retval = -ENOEXEC;
if (memcmp(elf_ex->e_ident, ELFMAG, SELFMAG) != 0)
goto out;
if (elf_ex->e_type != ET_EXEC && elf_ex->e_type != ET_DYN)
goto out;
if (!elf_check_arch(elf_ex))
goto out;
if (elf_check_fdpic(elf_ex))
goto out;
if (!bprm->file->f_op->mmap)
goto out;
elf_phdata = load_elf_phdrs(elf_ex, bprm->file);
if (!elf_phdata)
goto out;
elf_ppnt = elf_phdata;
for (i = 0; i < elf_ex->e_phnum; i++, elf_ppnt++) {
char *elf_interpreter;
if (elf_ppnt->p_type == PT_GNU_PROPERTY) {
elf_property_phdata = elf_ppnt;
continue;
}
if (elf_ppnt->p_type != PT_INTERP)
continue;
* This is the program interpreter used for shared libraries -
* for now assume that this is an a.out format binary.
*/
retval = -ENOEXEC;
if (elf_ppnt->p_filesz > PATH_MAX || elf_ppnt->p_filesz < 2)
goto out_free_ph;
retval = -ENOMEM;
elf_interpreter = kmalloc(elf_ppnt->p_filesz, GFP_KERNEL);
if (!elf_interpreter)
goto out_free_ph;
retval = elf_read(bprm->file, elf_interpreter, elf_ppnt->p_filesz,
elf_ppnt->p_offset);
if (retval < 0)
goto out_free_interp;
retval = -ENOEXEC;
if (elf_interpreter[elf_ppnt->p_filesz - 1] != '\0')
goto out_free_interp;
interpreter = open_exec(elf_interpreter);
kfree(elf_interpreter);
retval = PTR_ERR(interpreter);
if (IS_ERR(interpreter))
goto out_free_ph;
* If the binary is not readable then enforce mm->dumpable = 0
* regardless of the interpreter's permissions.
*/
would_dump(bprm, interpreter);
interp_elf_ex = kmalloc(sizeof(*interp_elf_ex), GFP_KERNEL);
if (!interp_elf_ex) {
retval = -ENOMEM;
goto out_free_file;
}
retval = elf_read(interpreter, interp_elf_ex,
sizeof(*interp_elf_ex), 0);
if (retval < 0)
goto out_free_dentry;
break;
out_free_interp:
kfree(elf_interpreter);
goto out_free_ph;
}
elf_ppnt = elf_phdata;
for (i = 0; i < elf_ex->e_phnum; i++, elf_ppnt++)
switch (elf_ppnt->p_type) {
case PT_GNU_STACK:
if (elf_ppnt->p_flags & PF_X)
executable_stack = EXSTACK_ENABLE_X;
else
executable_stack = EXSTACK_DISABLE_X;
break;
case PT_LOPROC ... PT_HIPROC:
retval = arch_elf_pt_proc(elf_ex, elf_ppnt,
bprm->file, false,
&arch_state);
if (retval)
goto out_free_dentry;
break;
}
if (interpreter) {
retval = -ELIBBAD;
if (memcmp(interp_elf_ex->e_ident, ELFMAG, SELFMAG) != 0)
goto out_free_dentry;
if (!elf_check_arch(interp_elf_ex) ||
elf_check_fdpic(interp_elf_ex))
goto out_free_dentry;
interp_elf_phdata = load_elf_phdrs(interp_elf_ex,
interpreter);
if (!interp_elf_phdata)
goto out_free_dentry;
elf_property_phdata = NULL;
elf_ppnt = interp_elf_phdata;
for (i = 0; i < interp_elf_ex->e_phnum; i++, elf_ppnt++)
switch (elf_ppnt->p_type) {
case PT_GNU_PROPERTY:
elf_property_phdata = elf_ppnt;
break;
case PT_LOPROC ... PT_HIPROC:
retval = arch_elf_pt_proc(interp_elf_ex,
elf_ppnt, interpreter,
true, &arch_state);
if (retval)
goto out_free_dentry;
break;
}
}
retval = parse_elf_properties(interpreter ?: bprm->file,
elf_property_phdata, &arch_state);
if (retval)
goto out_free_dentry;
* Allow arch code to reject the ELF at this point, whilst it's
* still possible to return an error to the code that invoked
* the exec syscall.
*/
retval = arch_check_elf(elf_ex,
!!interpreter, interp_elf_ex,
&arch_state);
if (retval)
goto out_free_dentry;
retval = begin_new_exec(bprm);
if (retval)
goto out_free_dentry;
may depend on the personality. */
SET_PERSONALITY2(*elf_ex, &arch_state);
if (elf_read_implies_exec(*elf_ex, executable_stack))
current->personality |= READ_IMPLIES_EXEC;
if (!(current->personality & ADDR_NO_RANDOMIZE) && snapshot_randomize_va_space)
current->flags |= PF_RANDOMIZE;
setup_new_exec(bprm);
change some of these later */
retval = setup_arg_pages(bprm, randomize_stack_top(STACK_TOP),
executable_stack);
if (retval < 0)
goto out_free_dentry;
elf_bss = 0;
elf_brk = 0;
start_code = ~0UL;
end_code = 0;
start_data = 0;
end_data = 0;
the correct location in memory. */
for(i = 0, elf_ppnt = elf_phdata;
i < elf_ex->e_phnum; i++, elf_ppnt++) {
int elf_prot, elf_flags;
unsigned long k, vaddr;
unsigned long total_size = 0;
unsigned long alignment;
if (elf_ppnt->p_type == PT_OHOS_RANDOMDATA) {
void *temp_buf = NULL;
if (elf_ppnt->p_memsz > PT_OHOS_RANDOMDATA_SIZE_LIMIT) {
retval = -EINVAL;
goto out_free_dentry;
}
temp_buf = vmalloc(elf_ppnt->p_memsz);
if (!temp_buf) {
retval = -ENOMEM;
goto out_free_dentry;
}
get_random_bytes(temp_buf, (int)elf_ppnt->p_memsz);
if (copy_to_user((void *)(elf_ppnt->p_vaddr + load_bias), temp_buf, (unsigned long)elf_ppnt->p_memsz)) {
retval = -EFAULT;
vfree(temp_buf);
goto out_free_dentry;
}
vfree(temp_buf);
continue;
}
if (elf_ppnt->p_type != PT_LOAD)
continue;
if (unlikely (elf_brk > elf_bss)) {
unsigned long nbyte;
before this one. Map anonymous pages, if needed,
and clear the area. */
retval = set_brk(elf_bss + load_bias,
elf_brk + load_bias,
bss_prot);
if (retval)
goto out_free_dentry;
nbyte = ELF_PAGEOFFSET(elf_bss);
if (nbyte) {
nbyte = ELF_MIN_ALIGN - nbyte;
if (nbyte > elf_brk - elf_bss)
nbyte = elf_brk - elf_bss;
if (clear_user((void __user *)elf_bss +
load_bias, nbyte)) {
* This bss-zeroing can fail if the ELF
* file specifies odd protections. So
* we don't check the return value
*/
}
}
}
elf_prot = make_prot(elf_ppnt->p_flags, &arch_state,
!!interpreter, false);
elf_flags = MAP_PRIVATE | MAP_DENYWRITE | MAP_EXECUTABLE;
vaddr = elf_ppnt->p_vaddr;
* If we are loading ET_EXEC or we have already performed
* the ET_DYN load_addr calculations, proceed normally.
*/
if (elf_ex->e_type == ET_EXEC || load_addr_set) {
elf_flags |= MAP_FIXED;
} else if (elf_ex->e_type == ET_DYN) {
* This logic is run once for the first LOAD Program
* Header for ET_DYN binaries to calculate the
* randomization (load_bias) for all the LOAD
* Program Headers, and to calculate the entire
* size of the ELF mapping (total_size). (Note that
* load_addr_set is set to true later once the
* initial mapping is performed.)
*
* There are effectively two types of ET_DYN
* binaries: programs (i.e. PIE: ET_DYN with INTERP)
* and loaders (ET_DYN without INTERP, since they
* _are_ the ELF interpreter). The loaders must
* be loaded away from programs since the program
* may otherwise collide with the loader (especially
* for ET_EXEC which does not have a randomized
* position). For example to handle invocations of
* "./ld.so someprog" to test out a new version of
* the loader, the subsequent program that the
* loader loads must avoid the loader itself, so
* they cannot share the same load range. Sufficient
* room for the brk must be allocated with the
* loader as well, since brk must be available with
* the loader.
*
* Therefore, programs are loaded offset from
* ELF_ET_DYN_BASE and loaders are loaded into the
* independently randomized mmap region (0 load_bias
* without MAP_FIXED).
*/
if (interpreter) {
load_bias = ELF_ET_DYN_BASE;
if (current->flags & PF_RANDOMIZE)
load_bias += arch_mmap_rnd();
alignment = maximum_alignment(elf_phdata, elf_ex->e_phnum);
if (alignment)
load_bias &= ~(alignment - 1);
elf_flags |= MAP_FIXED;
} else
load_bias = 0;
* Since load_bias is used for all subsequent loading
* calculations, we must lower it by the first vaddr
* so that the remaining calculations based on the
* ELF vaddrs will be correctly offset. The result
* is then page aligned.
*/
load_bias = ELF_PAGESTART(load_bias - vaddr);
total_size = total_mapping_size(elf_phdata,
elf_ex->e_phnum);
if (!total_size) {
retval = -EINVAL;
goto out_free_dentry;
}
}
error = elf_map(bprm->file, load_bias + vaddr, elf_ppnt,
elf_prot, elf_flags, total_size);
if (BAD_ADDR(error)) {
retval = IS_ERR((void *)error) ?
PTR_ERR((void*)error) : -EINVAL;
goto out_free_dentry;
}
if (!load_addr_set) {
load_addr_set = 1;
load_addr = (elf_ppnt->p_vaddr - elf_ppnt->p_offset);
if (elf_ex->e_type == ET_DYN) {
load_bias += error -
ELF_PAGESTART(load_bias + vaddr);
load_addr += load_bias;
reloc_func_desc = load_bias;
}
}
* Figure out which segment in the file contains the Program
* Header table, and map to the associated memory address.
*/
if (elf_ppnt->p_offset <= elf_ex->e_phoff &&
elf_ex->e_phoff < elf_ppnt->p_offset + elf_ppnt->p_filesz) {
phdr_addr = elf_ex->e_phoff - elf_ppnt->p_offset +
elf_ppnt->p_vaddr;
}
k = elf_ppnt->p_vaddr;
if ((elf_ppnt->p_flags & PF_X) && k < start_code)
start_code = k;
if (start_data < k)
start_data = k;
* Check to see if the section's size will overflow the
* allowed task size. Note that p_filesz must always be
* <= p_memsz so it is only necessary to check p_memsz.
*/
if (BAD_ADDR(k) || elf_ppnt->p_filesz > elf_ppnt->p_memsz ||
elf_ppnt->p_memsz > TASK_SIZE ||
TASK_SIZE - elf_ppnt->p_memsz < k) {
retval = -EINVAL;
goto out_free_dentry;
}
k = elf_ppnt->p_vaddr + elf_ppnt->p_filesz;
if (k > elf_bss)
elf_bss = k;
if ((elf_ppnt->p_flags & PF_X) && end_code < k)
end_code = k;
if (end_data < k)
end_data = k;
k = elf_ppnt->p_vaddr + elf_ppnt->p_memsz;
if (k > elf_brk) {
bss_prot = elf_prot;
elf_brk = k;
}
}
e_entry = elf_ex->e_entry + load_bias;
phdr_addr += load_bias;
elf_bss += load_bias;
elf_brk += load_bias;
start_code += load_bias;
end_code += load_bias;
start_data += load_bias;
end_data += load_bias;
* for the bss and break sections. We must do this before
* mapping in the interpreter, to make sure it doesn't wind
* up getting placed where the bss needs to go.
*/
retval = set_brk(elf_bss, elf_brk, bss_prot);
if (retval)
goto out_free_dentry;
if (likely(elf_bss != elf_brk) && unlikely(padzero(elf_bss))) {
retval = -EFAULT;
goto out_free_dentry;
}
if (interpreter) {
elf_entry = load_elf_interp(interp_elf_ex,
interpreter,
load_bias, interp_elf_phdata,
&arch_state);
if (!IS_ERR((void *)elf_entry)) {
* load_elf_interp() returns relocation
* adjustment
*/
interp_load_addr = elf_entry;
elf_entry += interp_elf_ex->e_entry;
}
if (BAD_ADDR(elf_entry)) {
retval = IS_ERR((void *)elf_entry) ?
(int)elf_entry : -EINVAL;
goto out_free_dentry;
}
reloc_func_desc = interp_load_addr;
allow_write_access(interpreter);
fput(interpreter);
kfree(interp_elf_ex);
kfree(interp_elf_phdata);
} else {
elf_entry = e_entry;
if (BAD_ADDR(elf_entry)) {
retval = -EINVAL;
goto out_free_dentry;
}
}
kfree(elf_phdata);
set_binfmt(&elf_format);
#ifdef ARCH_HAS_SETUP_ADDITIONAL_PAGES
retval = arch_setup_additional_pages(bprm, !!interpreter);
if (retval < 0)
goto out;
#endif
retval = create_elf_tables(bprm, elf_ex, interp_load_addr,
e_entry, phdr_addr);
if (retval < 0)
goto out;
mm = current->mm;
mm->end_code = end_code;
mm->start_code = start_code;
mm->start_data = start_data;
mm->end_data = end_data;
mm->start_stack = bprm->p;
if ((current->flags & PF_RANDOMIZE) && (snapshot_randomize_va_space > 1)) {
* For architectures with ELF randomization, when executing
* a loader directly (i.e. no interpreter listed in ELF
* headers), move the brk area out of the mmap region
* (since it grows up, and may collide early with the stack
* growing down), and into the unused ELF_ET_DYN_BASE region.
*/
if (IS_ENABLED(CONFIG_ARCH_HAS_ELF_RANDOMIZE) &&
elf_ex->e_type == ET_DYN && !interpreter) {
mm->brk = mm->start_brk = ELF_ET_DYN_BASE;
}
mm->brk = mm->start_brk = arch_randomize_brk(mm);
#ifdef compat_brk_randomized
current->brk_randomized = 1;
#endif
}
if (current->personality & MMAP_PAGE_ZERO) {
and some applications "depend" upon this behavior.
Since we do not have the power to recompile these, we
emulate the SVr4 behavior. Sigh. */
error = vm_mmap(NULL, 0, PAGE_SIZE, PROT_READ | PROT_EXEC,
MAP_FIXED | MAP_PRIVATE, 0);
}
regs = current_pt_regs();
#ifdef ELF_PLAT_INIT
* The ABI may specify that certain registers be set up in special
* ways (on i386 %edx is the address of a DT_FINI function, for
* example. In addition, it may also specify (eg, PowerPC64 ELF)
* that the e_entry field is the address of the function descriptor
* for the startup routine, rather than the address of the startup
* routine itself. This macro performs whatever initialization to
* the regs structure is required as well as any relocations to the
* function descriptor entries when executing dynamically links apps.
*/
ELF_PLAT_INIT(regs, reloc_func_desc);
#endif
finalize_exec(bprm);
start_thread(regs, elf_entry, bprm->p);
retval = 0;
out:
return retval;
out_free_dentry:
kfree(interp_elf_ex);
kfree(interp_elf_phdata);
out_free_file:
allow_write_access(interpreter);
if (interpreter)
fput(interpreter);
out_free_ph:
kfree(elf_phdata);
goto out;
}
#ifdef CONFIG_USELIB
a.out library that is given an ELF header. */
static int load_elf_library(struct file *file)
{
struct elf_phdr *elf_phdata;
struct elf_phdr *eppnt;
unsigned long elf_bss, bss, len;
int retval, error, i, j;
struct elfhdr elf_ex;
error = -ENOEXEC;
retval = elf_read(file, &elf_ex, sizeof(elf_ex), 0);
if (retval < 0)
goto out;
if (memcmp(elf_ex.e_ident, ELFMAG, SELFMAG) != 0)
goto out;
if (elf_ex.e_type != ET_EXEC || elf_ex.e_phnum > 2 ||
!elf_check_arch(&elf_ex) || !file->f_op->mmap)
goto out;
if (elf_check_fdpic(&elf_ex))
goto out;
j = sizeof(struct elf_phdr) * elf_ex.e_phnum;
error = -ENOMEM;
elf_phdata = kmalloc(j, GFP_KERNEL);
if (!elf_phdata)
goto out;
eppnt = elf_phdata;
error = -ENOEXEC;
retval = elf_read(file, eppnt, j, elf_ex.e_phoff);
if (retval < 0)
goto out_free_ph;
for (j = 0, i = 0; i<elf_ex.e_phnum; i++)
if ((eppnt + i)->p_type == PT_LOAD)
j++;
if (j != 1)
goto out_free_ph;
while (eppnt->p_type != PT_LOAD)
eppnt++;
error = vm_mmap(file,
ELF_PAGESTART(eppnt->p_vaddr),
(eppnt->p_filesz +
ELF_PAGEOFFSET(eppnt->p_vaddr)),
PROT_READ | PROT_WRITE | PROT_EXEC,
MAP_FIXED_NOREPLACE | MAP_PRIVATE | MAP_DENYWRITE,
(eppnt->p_offset -
ELF_PAGEOFFSET(eppnt->p_vaddr)));
if (error != ELF_PAGESTART(eppnt->p_vaddr))
goto out_free_ph;
elf_bss = eppnt->p_vaddr + eppnt->p_filesz;
if (padzero(elf_bss)) {
error = -EFAULT;
goto out_free_ph;
}
len = ELF_PAGEALIGN(eppnt->p_filesz + eppnt->p_vaddr);
bss = ELF_PAGEALIGN(eppnt->p_memsz + eppnt->p_vaddr);
if (bss > len) {
error = vm_brk(len, bss - len);
if (error)
goto out_free_ph;
}
error = 0;
out_free_ph:
kfree(elf_phdata);
out:
return error;
}
#endif
#ifdef CONFIG_ELF_CORE
* ELF core dumper
*
* Modelled on fs/exec.c:aout_core_dump()
* Jeremy Fitzhardinge <jeremy@sw.oz.au>
*/
struct memelfnote
{
const char *name;
int type;
unsigned int datasz;
void *data;
};
static int notesize(struct memelfnote *en)
{
int sz;
sz = sizeof(struct elf_note);
sz += roundup(strlen(en->name) + 1, 4);
sz += roundup(en->datasz, 4);
return sz;
}
static int writenote(struct memelfnote *men, struct coredump_params *cprm)
{
struct elf_note en;
en.n_namesz = strlen(men->name) + 1;
en.n_descsz = men->datasz;
en.n_type = men->type;
return dump_emit(cprm, &en, sizeof(en)) &&
dump_emit(cprm, men->name, en.n_namesz) && dump_align(cprm, 4) &&
dump_emit(cprm, men->data, men->datasz) && dump_align(cprm, 4);
}
static void fill_elf_header(struct elfhdr *elf, int segs,
u16 machine, u32 flags)
{
memset(elf, 0, sizeof(*elf));
memcpy(elf->e_ident, ELFMAG, SELFMAG);
elf->e_ident[EI_CLASS] = ELF_CLASS;
elf->e_ident[EI_DATA] = ELF_DATA;
elf->e_ident[EI_VERSION] = EV_CURRENT;
elf->e_ident[EI_OSABI] = ELF_OSABI;
elf->e_type = ET_CORE;
elf->e_machine = machine;
elf->e_version = EV_CURRENT;
elf->e_phoff = sizeof(struct elfhdr);
elf->e_flags = flags;
elf->e_ehsize = sizeof(struct elfhdr);
elf->e_phentsize = sizeof(struct elf_phdr);
elf->e_phnum = segs;
}
static void fill_elf_note_phdr(struct elf_phdr *phdr, int sz, loff_t offset)
{
phdr->p_type = PT_NOTE;
phdr->p_offset = offset;
phdr->p_vaddr = 0;
phdr->p_paddr = 0;
phdr->p_filesz = sz;
phdr->p_memsz = 0;
phdr->p_flags = 0;
phdr->p_align = 0;
}
static void fill_note(struct memelfnote *note, const char *name, int type,
unsigned int sz, void *data)
{
note->name = name;
note->type = type;
note->datasz = sz;
note->data = data;
}
* fill up all the fields in prstatus from the given task struct, except
* registers which need to be filled up separately.
*/
static void fill_prstatus(struct elf_prstatus *prstatus,
struct task_struct *p, long signr)
{
prstatus->pr_info.si_signo = prstatus->pr_cursig = signr;
prstatus->pr_sigpend = p->pending.signal.sig[0];
prstatus->pr_sighold = p->blocked.sig[0];
rcu_read_lock();
prstatus->pr_ppid = task_pid_vnr(rcu_dereference(p->real_parent));
rcu_read_unlock();
prstatus->pr_pid = task_pid_vnr(p);
prstatus->pr_pgrp = task_pgrp_vnr(p);
prstatus->pr_sid = task_session_vnr(p);
if (thread_group_leader(p)) {
struct task_cputime cputime;
* This is the record for the group leader. It shows the
* group-wide total, not its individual thread total.
*/
thread_group_cputime(p, &cputime);
prstatus->pr_utime = ns_to_kernel_old_timeval(cputime.utime);
prstatus->pr_stime = ns_to_kernel_old_timeval(cputime.stime);
} else {
u64 utime, stime;
task_cputime(p, &utime, &stime);
prstatus->pr_utime = ns_to_kernel_old_timeval(utime);
prstatus->pr_stime = ns_to_kernel_old_timeval(stime);
}
prstatus->pr_cutime = ns_to_kernel_old_timeval(p->signal->cutime);
prstatus->pr_cstime = ns_to_kernel_old_timeval(p->signal->cstime);
}
static int fill_psinfo(struct elf_prpsinfo *psinfo, struct task_struct *p,
struct mm_struct *mm)
{
const struct cred *cred;
unsigned int i, len;
memset(psinfo, 0, sizeof(struct elf_prpsinfo));
len = mm->arg_end - mm->arg_start;
if (len >= ELF_PRARGSZ)
len = ELF_PRARGSZ-1;
if (copy_from_user(&psinfo->pr_psargs,
(const char __user *)mm->arg_start, len))
return -EFAULT;
for(i = 0; i < len; i++)
if (psinfo->pr_psargs[i] == 0)
psinfo->pr_psargs[i] = ' ';
psinfo->pr_psargs[len] = 0;
rcu_read_lock();
psinfo->pr_ppid = task_pid_vnr(rcu_dereference(p->real_parent));
rcu_read_unlock();
psinfo->pr_pid = task_pid_vnr(p);
psinfo->pr_pgrp = task_pgrp_vnr(p);
psinfo->pr_sid = task_session_vnr(p);
i = p->state ? ffz(~p->state) + 1 : 0;
psinfo->pr_state = i;
psinfo->pr_sname = (i > 5) ? '.' : "RSDTZW"[i];
psinfo->pr_zomb = psinfo->pr_sname == 'Z';
psinfo->pr_nice = task_nice(p);
psinfo->pr_flag = p->flags;
rcu_read_lock();
cred = __task_cred(p);
SET_UID(psinfo->pr_uid, from_kuid_munged(cred->user_ns, cred->uid));
SET_GID(psinfo->pr_gid, from_kgid_munged(cred->user_ns, cred->gid));
rcu_read_unlock();
strncpy(psinfo->pr_fname, p->comm, sizeof(psinfo->pr_fname));
return 0;
}
static void fill_auxv_note(struct memelfnote *note, struct mm_struct *mm)
{
elf_addr_t *auxv = (elf_addr_t *) mm->saved_auxv;
int i = 0;
do
i += 2;
while (auxv[i - 2] != AT_NULL);
fill_note(note, "CORE", NT_AUXV, i * sizeof(elf_addr_t), auxv);
}
static void fill_siginfo_note(struct memelfnote *note, user_siginfo_t *csigdata,
const kernel_siginfo_t *siginfo)
{
copy_siginfo_to_external(csigdata, siginfo);
fill_note(note, "CORE", NT_SIGINFO, sizeof(*csigdata), csigdata);
}
#define MAX_FILE_NOTE_SIZE (4*1024*1024)
* Format of NT_FILE note:
*
* long count -- how many files are mapped
* long page_size -- units for file_ofs
* array of [COUNT] elements of
* long start
* long end
* long file_ofs
* followed by COUNT filenames in ASCII: "FILE1" NUL "FILE2" NUL...
*/
static int fill_files_note(struct memelfnote *note, struct coredump_params *cprm)
{
unsigned count, size, names_ofs, remaining, n;
user_long_t *data;
user_long_t *start_end_ofs;
char *name_base, *name_curpos;
int i;
count = cprm->vma_count;
if (count > UINT_MAX / 64)
return -EINVAL;
size = count * 64;
names_ofs = (2 + 3 * count) * sizeof(data[0]);
alloc:
if (size >= MAX_FILE_NOTE_SIZE)
return -EINVAL;
size = round_up(size, PAGE_SIZE);
* "size" can be 0 here legitimately.
* Let it ENOMEM and omit NT_FILE section which will be empty anyway.
*/
data = kvmalloc(size, GFP_KERNEL);
if (ZERO_OR_NULL_PTR(data))
return -ENOMEM;
start_end_ofs = data + 2;
name_base = name_curpos = ((char *)data) + names_ofs;
remaining = size - names_ofs;
count = 0;
for (i = 0; i < cprm->vma_count; i++) {
struct core_vma_metadata *m = &cprm->vma_meta[i];
struct file *file;
const char *filename;
file = m->file;
if (!file)
continue;
filename = file_path(file, name_curpos, remaining);
if (IS_ERR(filename)) {
if (PTR_ERR(filename) == -ENAMETOOLONG) {
kvfree(data);
size = size * 5 / 4;
goto alloc;
}
continue;
}
n = (name_curpos + remaining) - filename;
remaining = filename - name_curpos;
memmove(name_curpos, filename, n);
name_curpos += n;
*start_end_ofs++ = m->start;
*start_end_ofs++ = m->end;
*start_end_ofs++ = m->pgoff;
count++;
}
data[0] = count;
data[1] = PAGE_SIZE;
* Count usually is less than mm->map_count,
* we need to move filenames down.
*/
n = cprm->vma_count - count;
if (n != 0) {
unsigned shift_bytes = n * 3 * sizeof(data[0]);
memmove(name_base - shift_bytes, name_base,
name_curpos - name_base);
name_curpos -= shift_bytes;
}
size = name_curpos - (char *)data;
fill_note(note, "CORE", NT_FILE, size, data);
return 0;
}
#ifdef CORE_DUMP_USE_REGSET
#include <linux/regset.h>
struct elf_thread_core_info {
struct elf_thread_core_info *next;
struct task_struct *task;
struct elf_prstatus prstatus;
struct memelfnote notes[];
};
struct elf_note_info {
struct elf_thread_core_info *thread;
struct memelfnote psinfo;
struct memelfnote signote;
struct memelfnote auxv;
struct memelfnote files;
user_siginfo_t csigdata;
size_t size;
int thread_notes;
};
* When a regset has a writeback hook, we call it on each thread before
* dumping user memory. On register window machines, this makes sure the
* user memory backing the register data is up to date before we read it.
*/
static void do_thread_regset_writeback(struct task_struct *task,
const struct user_regset *regset)
{
if (regset->writeback)
regset->writeback(task, regset, 1);
}
#ifndef PRSTATUS_SIZE
#define PRSTATUS_SIZE(S, R) sizeof(S)
#endif
#ifndef SET_PR_FPVALID
#define SET_PR_FPVALID(S, V, R) ((S)->pr_fpvalid = (V))
#endif
static int fill_thread_core_info(struct elf_thread_core_info *t,
const struct user_regset_view *view,
long signr, size_t *total)
{
unsigned int i;
int regset0_size;
* NT_PRSTATUS is the one special case, because the regset data
* goes into the pr_reg field inside the note contents, rather
* than being the whole note contents. We fill the reset in here.
* We assume that regset 0 is NT_PRSTATUS.
*/
fill_prstatus(&t->prstatus, t->task, signr);
regset0_size = regset_get(t->task, &view->regsets[0],
sizeof(t->prstatus.pr_reg), &t->prstatus.pr_reg);
if (regset0_size < 0)
return 0;
fill_note(&t->notes[0], "CORE", NT_PRSTATUS,
PRSTATUS_SIZE(t->prstatus, regset0_size), &t->prstatus);
*total += notesize(&t->notes[0]);
do_thread_regset_writeback(t->task, &view->regsets[0]);
* Each other regset might generate a note too. For each regset
* that has no core_note_type or is inactive, we leave t->notes[i]
* all zero and we'll know to skip writing it later.
*/
for (i = 1; i < view->n; ++i) {
const struct user_regset *regset = &view->regsets[i];
int note_type = regset->core_note_type;
bool is_fpreg = note_type == NT_PRFPREG;
void *data;
int ret;
do_thread_regset_writeback(t->task, regset);
if (!note_type)
continue;
if (regset->active && regset->active(t->task, regset) <= 0)
continue;
ret = regset_get_alloc(t->task, regset, ~0U, &data);
if (ret < 0)
continue;
if (is_fpreg)
SET_PR_FPVALID(&t->prstatus, 1, regset0_size);
fill_note(&t->notes[i], is_fpreg ? "CORE" : "LINUX",
note_type, ret, data);
*total += notesize(&t->notes[i]);
}
return 1;
}
static int fill_note_info(struct elfhdr *elf, int phdrs,
struct elf_note_info *info,
struct coredump_params *cprm)
{
struct task_struct *dump_task = current;
const struct user_regset_view *view = task_user_regset_view(dump_task);
struct elf_thread_core_info *t;
struct elf_prpsinfo *psinfo;
struct core_thread *ct;
unsigned int i;
info->size = 0;
info->thread = NULL;
psinfo = kmalloc(sizeof(*psinfo), GFP_KERNEL);
if (psinfo == NULL) {
info->psinfo.data = NULL;
return 0;
}
fill_note(&info->psinfo, "CORE", NT_PRPSINFO, sizeof(*psinfo), psinfo);
* Figure out how many notes we're going to need for each thread.
*/
info->thread_notes = 0;
for (i = 0; i < view->n; ++i)
if (view->regsets[i].core_note_type != 0)
++info->thread_notes;
* Sanity check. We rely on regset 0 being in NT_PRSTATUS,
* since it is our one special case.
*/
if (unlikely(info->thread_notes == 0) ||
unlikely(view->regsets[0].core_note_type != NT_PRSTATUS)) {
WARN_ON(1);
return 0;
}
* Initialize the ELF file header.
*/
fill_elf_header(elf, phdrs,
view->e_machine, view->e_flags);
* Allocate a structure for each thread.
*/
for (ct = &dump_task->mm->core_state->dumper; ct; ct = ct->next) {
t = kzalloc(offsetof(struct elf_thread_core_info,
notes[info->thread_notes]),
GFP_KERNEL);
if (unlikely(!t))
return 0;
t->task = ct->task;
if (ct->task == dump_task || !info->thread) {
t->next = info->thread;
info->thread = t;
} else {
* Make sure to keep the original task at
* the head of the list.
*/
t->next = info->thread->next;
info->thread->next = t;
}
}
* Now fill in each thread's information.
*/
for (t = info->thread; t != NULL; t = t->next)
if (!fill_thread_core_info(t, view, cprm->siginfo->si_signo, &info->size))
return 0;
* Fill in the two process-wide notes.
*/
fill_psinfo(psinfo, dump_task->group_leader, dump_task->mm);
info->size += notesize(&info->psinfo);
fill_siginfo_note(&info->signote, &info->csigdata, cprm->siginfo);
info->size += notesize(&info->signote);
fill_auxv_note(&info->auxv, current->mm);
info->size += notesize(&info->auxv);
if (fill_files_note(&info->files, cprm) == 0)
info->size += notesize(&info->files);
return 1;
}
static size_t get_note_info_size(struct elf_note_info *info)
{
return info->size;
}
* Write all the notes for each thread. When writing the first thread, the
* process-wide notes are interleaved after the first thread-specific note.
*/
static int write_note_info(struct elf_note_info *info,
struct coredump_params *cprm)
{
bool first = true;
struct elf_thread_core_info *t = info->thread;
do {
int i;
if (!writenote(&t->notes[0], cprm))
return 0;
if (first && !writenote(&info->psinfo, cprm))
return 0;
if (first && !writenote(&info->signote, cprm))
return 0;
if (first && !writenote(&info->auxv, cprm))
return 0;
if (first && info->files.data &&
!writenote(&info->files, cprm))
return 0;
for (i = 1; i < info->thread_notes; ++i)
if (t->notes[i].data &&
!writenote(&t->notes[i], cprm))
return 0;
first = false;
t = t->next;
} while (t);
return 1;
}
static void free_note_info(struct elf_note_info *info)
{
struct elf_thread_core_info *threads = info->thread;
while (threads) {
unsigned int i;
struct elf_thread_core_info *t = threads;
threads = t->next;
WARN_ON(t->notes[0].data && t->notes[0].data != &t->prstatus);
for (i = 1; i < info->thread_notes; ++i)
kfree(t->notes[i].data);
kfree(t);
}
kfree(info->psinfo.data);
kvfree(info->files.data);
}
#else
struct elf_thread_status
{
struct list_head list;
struct elf_prstatus prstatus;
elf_fpregset_t fpu;
struct task_struct *thread;
struct memelfnote notes[3];
int num_notes;
};
* In order to add the specific thread information for the elf file format,
* we need to keep a linked list of every threads pr_status and then create
* a single section for them in the final core file.
*/
static int elf_dump_thread_status(long signr, struct elf_thread_status *t)
{
int sz = 0;
struct task_struct *p = t->thread;
t->num_notes = 0;
fill_prstatus(&t->prstatus, p, signr);
elf_core_copy_task_regs(p, &t->prstatus.pr_reg);
fill_note(&t->notes[0], "CORE", NT_PRSTATUS, sizeof(t->prstatus),
&(t->prstatus));
t->num_notes++;
sz += notesize(&t->notes[0]);
if ((t->prstatus.pr_fpvalid = elf_core_copy_task_fpregs(p, NULL,
&t->fpu))) {
fill_note(&t->notes[1], "CORE", NT_PRFPREG, sizeof(t->fpu),
&(t->fpu));
t->num_notes++;
sz += notesize(&t->notes[1]);
}
return sz;
}
struct elf_note_info {
struct memelfnote *notes;
struct memelfnote *notes_files;
struct elf_prstatus *prstatus;
struct elf_prpsinfo *psinfo;
struct list_head thread_list;
elf_fpregset_t *fpu;
user_siginfo_t csigdata;
int thread_status_size;
int numnote;
};
static int elf_note_info_init(struct elf_note_info *info)
{
memset(info, 0, sizeof(*info));
INIT_LIST_HEAD(&info->thread_list);
info->notes = kmalloc_array(8, sizeof(struct memelfnote), GFP_KERNEL);
if (!info->notes)
return 0;
info->psinfo = kmalloc(sizeof(*info->psinfo), GFP_KERNEL);
if (!info->psinfo)
return 0;
info->prstatus = kmalloc(sizeof(*info->prstatus), GFP_KERNEL);
if (!info->prstatus)
return 0;
info->fpu = kmalloc(sizeof(*info->fpu), GFP_KERNEL);
if (!info->fpu)
return 0;
return 1;
}
static int fill_note_info(struct elfhdr *elf, int phdrs,
struct elf_note_info *info,
struct coredump_params *cprm)
{
struct core_thread *ct;
struct elf_thread_status *ets;
if (!elf_note_info_init(info))
return 0;
for (ct = current->mm->core_state->dumper.next;
ct; ct = ct->next) {
ets = kzalloc(sizeof(*ets), GFP_KERNEL);
if (!ets)
return 0;
ets->thread = ct->task;
list_add(&ets->list, &info->thread_list);
}
list_for_each_entry(ets, &info->thread_list, list) {
int sz;
sz = elf_dump_thread_status(cprm->siginfo->si_signo, ets);
info->thread_status_size += sz;
}
memset(info->prstatus, 0, sizeof(*info->prstatus));
fill_prstatus(info->prstatus, current, cprm->siginfo->si_signo);
elf_core_copy_regs(&info->prstatus->pr_reg, cprm->regs);
fill_elf_header(elf, phdrs, ELF_ARCH, ELF_CORE_EFLAGS);
* Set up the notes in similar form to SVR4 core dumps made
* with info from their /proc.
*/
fill_note(info->notes + 0, "CORE", NT_PRSTATUS,
sizeof(*info->prstatus), info->prstatus);
fill_psinfo(info->psinfo, current->group_leader, current->mm);
fill_note(info->notes + 1, "CORE", NT_PRPSINFO,
sizeof(*info->psinfo), info->psinfo);
fill_siginfo_note(info->notes + 2, &info->csigdata, cprm->siginfo);
fill_auxv_note(info->notes + 3, current->mm);
info->numnote = 4;
if (fill_files_note(info->notes + info->numnote, cprm) == 0) {
info->notes_files = info->notes + info->numnote;
info->numnote++;
}
info->prstatus->pr_fpvalid =
elf_core_copy_task_fpregs(current, cprm->regs, info->fpu);
if (info->prstatus->pr_fpvalid)
fill_note(info->notes + info->numnote++,
"CORE", NT_PRFPREG, sizeof(*info->fpu), info->fpu);
return 1;
}
static size_t get_note_info_size(struct elf_note_info *info)
{
int sz = 0;
int i;
for (i = 0; i < info->numnote; i++)
sz += notesize(info->notes + i);
sz += info->thread_status_size;
return sz;
}
static int write_note_info(struct elf_note_info *info,
struct coredump_params *cprm)
{
struct elf_thread_status *ets;
int i;
for (i = 0; i < info->numnote; i++)
if (!writenote(info->notes + i, cprm))
return 0;
list_for_each_entry(ets, &info->thread_list, list) {
for (i = 0; i < ets->num_notes; i++)
if (!writenote(&ets->notes[i], cprm))
return 0;
}
return 1;
}
static void free_note_info(struct elf_note_info *info)
{
while (!list_empty(&info->thread_list)) {
struct list_head *tmp = info->thread_list.next;
list_del(tmp);
kfree(list_entry(tmp, struct elf_thread_status, list));
}
if (info->notes_files)
kvfree(info->notes_files->data);
kfree(info->prstatus);
kfree(info->psinfo);
kfree(info->notes);
kfree(info->fpu);
}
#endif
static void fill_extnum_info(struct elfhdr *elf, struct elf_shdr *shdr4extnum,
elf_addr_t e_shoff, int segs)
{
elf->e_shoff = e_shoff;
elf->e_shentsize = sizeof(*shdr4extnum);
elf->e_shnum = 1;
elf->e_shstrndx = SHN_UNDEF;
memset(shdr4extnum, 0, sizeof(*shdr4extnum));
shdr4extnum->sh_type = SHT_NULL;
shdr4extnum->sh_size = elf->e_shnum;
shdr4extnum->sh_link = elf->e_shstrndx;
shdr4extnum->sh_info = segs;
}
* Actual dumper
*
* This is a two-pass process; first we find the offsets of the bits,
* and then they are actually written out. If we run out of core limit
* we just truncate.
*/
static int elf_core_dump(struct coredump_params *cprm)
{
int has_dumped = 0;
int segs, i;
struct elfhdr elf;
loff_t offset = 0, dataoff;
struct elf_note_info info = { };
struct elf_phdr *phdr4note = NULL;
struct elf_shdr *shdr4extnum = NULL;
Elf_Half e_phnum;
elf_addr_t e_shoff;
* The number of segs are recored into ELF header as 16bit value.
* Please check DEFAULT_MAX_MAP_COUNT definition when you modify here.
*/
segs = cprm->vma_count + elf_core_extra_phdrs();
segs++;
* this, kernel supports extended numbering. Have a look at
* include/linux/elf.h for further information. */
e_phnum = segs > PN_XNUM ? PN_XNUM : segs;
* Collect all the non-memory information about the process for the
* notes. This also sets up the file header.
*/
if (!fill_note_info(&elf, e_phnum, &info, cprm))
goto end_coredump;
has_dumped = 1;
offset += sizeof(elf);
offset += segs * sizeof(struct elf_phdr);
{
size_t sz = get_note_info_size(&info);
sz += elf_coredump_extra_notes_size();
phdr4note = kmalloc(sizeof(*phdr4note), GFP_KERNEL);
if (!phdr4note)
goto end_coredump;
fill_elf_note_phdr(phdr4note, sz, offset);
offset += sz;
}
dataoff = offset = roundup(offset, ELF_EXEC_PAGESIZE);
offset += cprm->vma_data_size;
offset += elf_core_extra_data_size();
e_shoff = offset;
if (e_phnum == PN_XNUM) {
shdr4extnum = kmalloc(sizeof(*shdr4extnum), GFP_KERNEL);
if (!shdr4extnum)
goto end_coredump;
fill_extnum_info(&elf, shdr4extnum, e_shoff, segs);
}
offset = dataoff;
if (!dump_emit(cprm, &elf, sizeof(elf)))
goto end_coredump;
if (!dump_emit(cprm, phdr4note, sizeof(*phdr4note)))
goto end_coredump;
for (i = 0; i < cprm->vma_count; i++) {
struct core_vma_metadata *meta = cprm->vma_meta + i;
struct elf_phdr phdr;
phdr.p_type = PT_LOAD;
phdr.p_offset = offset;
phdr.p_vaddr = meta->start;
phdr.p_paddr = 0;
phdr.p_filesz = meta->dump_size;
phdr.p_memsz = meta->end - meta->start;
offset += phdr.p_filesz;
phdr.p_flags = 0;
if (meta->flags & VM_READ)
phdr.p_flags |= PF_R;
if (meta->flags & VM_WRITE)
phdr.p_flags |= PF_W;
if (meta->flags & VM_EXEC)
phdr.p_flags |= PF_X;
phdr.p_align = ELF_EXEC_PAGESIZE;
if (!dump_emit(cprm, &phdr, sizeof(phdr)))
goto end_coredump;
}
if (!elf_core_write_extra_phdrs(cprm, offset))
goto end_coredump;
if (!write_note_info(&info, cprm))
goto end_coredump;
if (elf_coredump_extra_notes_write(cprm))
goto end_coredump;
if (!dump_skip(cprm, dataoff - cprm->pos))
goto end_coredump;
for (i = 0; i < cprm->vma_count; i++) {
struct core_vma_metadata *meta = cprm->vma_meta + i;
if (!dump_user_range(cprm, meta->start, meta->dump_size))
goto end_coredump;
}
dump_truncate(cprm);
if (!elf_core_write_extra_data(cprm))
goto end_coredump;
if (e_phnum == PN_XNUM) {
if (!dump_emit(cprm, shdr4extnum, sizeof(*shdr4extnum)))
goto end_coredump;
}
end_coredump:
free_note_info(&info);
kfree(shdr4extnum);
kfree(phdr4note);
return has_dumped;
}
#endif
static int __init init_elf_binfmt(void)
{
register_binfmt(&elf_format);
return 0;
}
static void __exit exit_elf_binfmt(void)
{
unregister_binfmt(&elf_format);
}
core_initcall(init_elf_binfmt);
module_exit(exit_elf_binfmt);
MODULE_LICENSE("GPL");