linux/init/initramfs.c
Deepa Dinamani aaed2dd8a3 utimes: Make utimes y2038 safe
struct timespec is not y2038 safe on 32 bit machines.
Replace timespec with y2038 safe struct timespec64.

Note that the patch only changes the internals without
modifying the syscall interfaces. This will be part
of a separate series.

Signed-off-by: Deepa Dinamani <deepa.kernel@gmail.com>
Reviewed-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2017-09-03 20:24:30 -04:00

665 lines
14 KiB
C

/*
* Many of the syscalls used in this file expect some of the arguments
* to be __user pointers not __kernel pointers. To limit the sparse
* noise, turn off sparse checking for this file.
*/
#ifdef __CHECKER__
#undef __CHECKER__
#warning "Sparse checking disabled for this file"
#endif
#include <linux/init.h>
#include <linux/fs.h>
#include <linux/slab.h>
#include <linux/types.h>
#include <linux/fcntl.h>
#include <linux/delay.h>
#include <linux/string.h>
#include <linux/dirent.h>
#include <linux/syscalls.h>
#include <linux/utime.h>
#include <linux/file.h>
static ssize_t __init xwrite(int fd, const char *p, size_t count)
{
ssize_t out = 0;
/* sys_write only can write MAX_RW_COUNT aka 2G-4K bytes at most */
while (count) {
ssize_t rv = sys_write(fd, p, count);
if (rv < 0) {
if (rv == -EINTR || rv == -EAGAIN)
continue;
return out ? out : rv;
} else if (rv == 0)
break;
p += rv;
out += rv;
count -= rv;
}
return out;
}
static __initdata char *message;
static void __init error(char *x)
{
if (!message)
message = x;
}
/* link hash */
#define N_ALIGN(len) ((((len) + 1) & ~3) + 2)
static __initdata struct hash {
int ino, minor, major;
umode_t mode;
struct hash *next;
char name[N_ALIGN(PATH_MAX)];
} *head[32];
static inline int hash(int major, int minor, int ino)
{
unsigned long tmp = ino + minor + (major << 3);
tmp += tmp >> 5;
return tmp & 31;
}
static char __init *find_link(int major, int minor, int ino,
umode_t mode, char *name)
{
struct hash **p, *q;
for (p = head + hash(major, minor, ino); *p; p = &(*p)->next) {
if ((*p)->ino != ino)
continue;
if ((*p)->minor != minor)
continue;
if ((*p)->major != major)
continue;
if (((*p)->mode ^ mode) & S_IFMT)
continue;
return (*p)->name;
}
q = kmalloc(sizeof(struct hash), GFP_KERNEL);
if (!q)
panic("can't allocate link hash entry");
q->major = major;
q->minor = minor;
q->ino = ino;
q->mode = mode;
strcpy(q->name, name);
q->next = NULL;
*p = q;
return NULL;
}
static void __init free_hash(void)
{
struct hash **p, *q;
for (p = head; p < head + 32; p++) {
while (*p) {
q = *p;
*p = q->next;
kfree(q);
}
}
}
static long __init do_utime(char *filename, time_t mtime)
{
struct timespec64 t[2];
t[0].tv_sec = mtime;
t[0].tv_nsec = 0;
t[1].tv_sec = mtime;
t[1].tv_nsec = 0;
return do_utimes(AT_FDCWD, filename, t, AT_SYMLINK_NOFOLLOW);
}
static __initdata LIST_HEAD(dir_list);
struct dir_entry {
struct list_head list;
char *name;
time_t mtime;
};
static void __init dir_add(const char *name, time_t mtime)
{
struct dir_entry *de = kmalloc(sizeof(struct dir_entry), GFP_KERNEL);
if (!de)
panic("can't allocate dir_entry buffer");
INIT_LIST_HEAD(&de->list);
de->name = kstrdup(name, GFP_KERNEL);
de->mtime = mtime;
list_add(&de->list, &dir_list);
}
static void __init dir_utime(void)
{
struct dir_entry *de, *tmp;
list_for_each_entry_safe(de, tmp, &dir_list, list) {
list_del(&de->list);
do_utime(de->name, de->mtime);
kfree(de->name);
kfree(de);
}
}
static __initdata time_t mtime;
/* cpio header parsing */
static __initdata unsigned long ino, major, minor, nlink;
static __initdata umode_t mode;
static __initdata unsigned long body_len, name_len;
static __initdata uid_t uid;
static __initdata gid_t gid;
static __initdata unsigned rdev;
static void __init parse_header(char *s)
{
unsigned long parsed[12];
char buf[9];
int i;
buf[8] = '\0';
for (i = 0, s += 6; i < 12; i++, s += 8) {
memcpy(buf, s, 8);
parsed[i] = simple_strtoul(buf, NULL, 16);
}
ino = parsed[0];
mode = parsed[1];
uid = parsed[2];
gid = parsed[3];
nlink = parsed[4];
mtime = parsed[5];
body_len = parsed[6];
major = parsed[7];
minor = parsed[8];
rdev = new_encode_dev(MKDEV(parsed[9], parsed[10]));
name_len = parsed[11];
}
/* FSM */
static __initdata enum state {
Start,
Collect,
GotHeader,
SkipIt,
GotName,
CopyFile,
GotSymlink,
Reset
} state, next_state;
static __initdata char *victim;
static unsigned long byte_count __initdata;
static __initdata loff_t this_header, next_header;
static inline void __init eat(unsigned n)
{
victim += n;
this_header += n;
byte_count -= n;
}
static __initdata char *vcollected;
static __initdata char *collected;
static long remains __initdata;
static __initdata char *collect;
static void __init read_into(char *buf, unsigned size, enum state next)
{
if (byte_count >= size) {
collected = victim;
eat(size);
state = next;
} else {
collect = collected = buf;
remains = size;
next_state = next;
state = Collect;
}
}
static __initdata char *header_buf, *symlink_buf, *name_buf;
static int __init do_start(void)
{
read_into(header_buf, 110, GotHeader);
return 0;
}
static int __init do_collect(void)
{
unsigned long n = remains;
if (byte_count < n)
n = byte_count;
memcpy(collect, victim, n);
eat(n);
collect += n;
if ((remains -= n) != 0)
return 1;
state = next_state;
return 0;
}
static int __init do_header(void)
{
if (memcmp(collected, "070707", 6)==0) {
error("incorrect cpio method used: use -H newc option");
return 1;
}
if (memcmp(collected, "070701", 6)) {
error("no cpio magic");
return 1;
}
parse_header(collected);
next_header = this_header + N_ALIGN(name_len) + body_len;
next_header = (next_header + 3) & ~3;
state = SkipIt;
if (name_len <= 0 || name_len > PATH_MAX)
return 0;
if (S_ISLNK(mode)) {
if (body_len > PATH_MAX)
return 0;
collect = collected = symlink_buf;
remains = N_ALIGN(name_len) + body_len;
next_state = GotSymlink;
state = Collect;
return 0;
}
if (S_ISREG(mode) || !body_len)
read_into(name_buf, N_ALIGN(name_len), GotName);
return 0;
}
static int __init do_skip(void)
{
if (this_header + byte_count < next_header) {
eat(byte_count);
return 1;
} else {
eat(next_header - this_header);
state = next_state;
return 0;
}
}
static int __init do_reset(void)
{
while (byte_count && *victim == '\0')
eat(1);
if (byte_count && (this_header & 3))
error("broken padding");
return 1;
}
static int __init maybe_link(void)
{
if (nlink >= 2) {
char *old = find_link(major, minor, ino, mode, collected);
if (old)
return (sys_link(old, collected) < 0) ? -1 : 1;
}
return 0;
}
static void __init clean_path(char *path, umode_t fmode)
{
struct kstat st;
if (!vfs_lstat(path, &st) && (st.mode ^ fmode) & S_IFMT) {
if (S_ISDIR(st.mode))
sys_rmdir(path);
else
sys_unlink(path);
}
}
static __initdata int wfd;
static int __init do_name(void)
{
state = SkipIt;
next_state = Reset;
if (strcmp(collected, "TRAILER!!!") == 0) {
free_hash();
return 0;
}
clean_path(collected, mode);
if (S_ISREG(mode)) {
int ml = maybe_link();
if (ml >= 0) {
int openflags = O_WRONLY|O_CREAT;
if (ml != 1)
openflags |= O_TRUNC;
wfd = sys_open(collected, openflags, mode);
if (wfd >= 0) {
sys_fchown(wfd, uid, gid);
sys_fchmod(wfd, mode);
if (body_len)
sys_ftruncate(wfd, body_len);
vcollected = kstrdup(collected, GFP_KERNEL);
state = CopyFile;
}
}
} else if (S_ISDIR(mode)) {
sys_mkdir(collected, mode);
sys_chown(collected, uid, gid);
sys_chmod(collected, mode);
dir_add(collected, mtime);
} else if (S_ISBLK(mode) || S_ISCHR(mode) ||
S_ISFIFO(mode) || S_ISSOCK(mode)) {
if (maybe_link() == 0) {
sys_mknod(collected, mode, rdev);
sys_chown(collected, uid, gid);
sys_chmod(collected, mode);
do_utime(collected, mtime);
}
}
return 0;
}
static int __init do_copy(void)
{
if (byte_count >= body_len) {
if (xwrite(wfd, victim, body_len) != body_len)
error("write error");
sys_close(wfd);
do_utime(vcollected, mtime);
kfree(vcollected);
eat(body_len);
state = SkipIt;
return 0;
} else {
if (xwrite(wfd, victim, byte_count) != byte_count)
error("write error");
body_len -= byte_count;
eat(byte_count);
return 1;
}
}
static int __init do_symlink(void)
{
collected[N_ALIGN(name_len) + body_len] = '\0';
clean_path(collected, 0);
sys_symlink(collected + N_ALIGN(name_len), collected);
sys_lchown(collected, uid, gid);
do_utime(collected, mtime);
state = SkipIt;
next_state = Reset;
return 0;
}
static __initdata int (*actions[])(void) = {
[Start] = do_start,
[Collect] = do_collect,
[GotHeader] = do_header,
[SkipIt] = do_skip,
[GotName] = do_name,
[CopyFile] = do_copy,
[GotSymlink] = do_symlink,
[Reset] = do_reset,
};
static long __init write_buffer(char *buf, unsigned long len)
{
byte_count = len;
victim = buf;
while (!actions[state]())
;
return len - byte_count;
}
static long __init flush_buffer(void *bufv, unsigned long len)
{
char *buf = (char *) bufv;
long written;
long origLen = len;
if (message)
return -1;
while ((written = write_buffer(buf, len)) < len && !message) {
char c = buf[written];
if (c == '0') {
buf += written;
len -= written;
state = Start;
} else if (c == 0) {
buf += written;
len -= written;
state = Reset;
} else
error("junk in compressed archive");
}
return origLen;
}
static unsigned long my_inptr; /* index of next byte to be processed in inbuf */
#include <linux/decompress/generic.h>
static char * __init unpack_to_rootfs(char *buf, unsigned long len)
{
long written;
decompress_fn decompress;
const char *compress_name;
static __initdata char msg_buf[64];
header_buf = kmalloc(110, GFP_KERNEL);
symlink_buf = kmalloc(PATH_MAX + N_ALIGN(PATH_MAX) + 1, GFP_KERNEL);
name_buf = kmalloc(N_ALIGN(PATH_MAX), GFP_KERNEL);
if (!header_buf || !symlink_buf || !name_buf)
panic("can't allocate buffers");
state = Start;
this_header = 0;
message = NULL;
while (!message && len) {
loff_t saved_offset = this_header;
if (*buf == '0' && !(this_header & 3)) {
state = Start;
written = write_buffer(buf, len);
buf += written;
len -= written;
continue;
}
if (!*buf) {
buf++;
len--;
this_header++;
continue;
}
this_header = 0;
decompress = decompress_method(buf, len, &compress_name);
pr_debug("Detected %s compressed data\n", compress_name);
if (decompress) {
int res = decompress(buf, len, NULL, flush_buffer, NULL,
&my_inptr, error);
if (res)
error("decompressor failed");
} else if (compress_name) {
if (!message) {
snprintf(msg_buf, sizeof msg_buf,
"compression method %s not configured",
compress_name);
message = msg_buf;
}
} else
error("junk in compressed archive");
if (state != Reset)
error("junk in compressed archive");
this_header = saved_offset + my_inptr;
buf += my_inptr;
len -= my_inptr;
}
dir_utime();
kfree(name_buf);
kfree(symlink_buf);
kfree(header_buf);
return message;
}
static int __initdata do_retain_initrd;
static int __init retain_initrd_param(char *str)
{
if (*str)
return 0;
do_retain_initrd = 1;
return 1;
}
__setup("retain_initrd", retain_initrd_param);
extern char __initramfs_start[];
extern unsigned long __initramfs_size;
#include <linux/initrd.h>
#include <linux/kexec.h>
static void __init free_initrd(void)
{
#ifdef CONFIG_KEXEC_CORE
unsigned long crashk_start = (unsigned long)__va(crashk_res.start);
unsigned long crashk_end = (unsigned long)__va(crashk_res.end);
#endif
if (do_retain_initrd)
goto skip;
#ifdef CONFIG_KEXEC_CORE
/*
* If the initrd region is overlapped with crashkernel reserved region,
* free only memory that is not part of crashkernel region.
*/
if (initrd_start < crashk_end && initrd_end > crashk_start) {
/*
* Initialize initrd memory region since the kexec boot does
* not do.
*/
memset((void *)initrd_start, 0, initrd_end - initrd_start);
if (initrd_start < crashk_start)
free_initrd_mem(initrd_start, crashk_start);
if (initrd_end > crashk_end)
free_initrd_mem(crashk_end, initrd_end);
} else
#endif
free_initrd_mem(initrd_start, initrd_end);
skip:
initrd_start = 0;
initrd_end = 0;
}
#ifdef CONFIG_BLK_DEV_RAM
#define BUF_SIZE 1024
static void __init clean_rootfs(void)
{
int fd;
void *buf;
struct linux_dirent64 *dirp;
int num;
fd = sys_open("/", O_RDONLY, 0);
WARN_ON(fd < 0);
if (fd < 0)
return;
buf = kzalloc(BUF_SIZE, GFP_KERNEL);
WARN_ON(!buf);
if (!buf) {
sys_close(fd);
return;
}
dirp = buf;
num = sys_getdents64(fd, dirp, BUF_SIZE);
while (num > 0) {
while (num > 0) {
struct kstat st;
int ret;
ret = vfs_lstat(dirp->d_name, &st);
WARN_ON_ONCE(ret);
if (!ret) {
if (S_ISDIR(st.mode))
sys_rmdir(dirp->d_name);
else
sys_unlink(dirp->d_name);
}
num -= dirp->d_reclen;
dirp = (void *)dirp + dirp->d_reclen;
}
dirp = buf;
memset(buf, 0, BUF_SIZE);
num = sys_getdents64(fd, dirp, BUF_SIZE);
}
sys_close(fd);
kfree(buf);
}
#endif
static int __init populate_rootfs(void)
{
/* Load the built in initramfs */
char *err = unpack_to_rootfs(__initramfs_start, __initramfs_size);
if (err)
panic("%s", err); /* Failed to decompress INTERNAL initramfs */
/* If available load the bootloader supplied initrd */
if (initrd_start && !IS_ENABLED(CONFIG_INITRAMFS_FORCE)) {
#ifdef CONFIG_BLK_DEV_RAM
int fd;
printk(KERN_INFO "Trying to unpack rootfs image as initramfs...\n");
err = unpack_to_rootfs((char *)initrd_start,
initrd_end - initrd_start);
if (!err) {
free_initrd();
goto done;
} else {
clean_rootfs();
unpack_to_rootfs(__initramfs_start, __initramfs_size);
}
printk(KERN_INFO "rootfs image is not initramfs (%s)"
"; looks like an initrd\n", err);
fd = sys_open("/initrd.image",
O_WRONLY|O_CREAT, 0700);
if (fd >= 0) {
ssize_t written = xwrite(fd, (char *)initrd_start,
initrd_end - initrd_start);
if (written != initrd_end - initrd_start)
pr_err("/initrd.image: incomplete write (%zd != %ld)\n",
written, initrd_end - initrd_start);
sys_close(fd);
free_initrd();
}
done:
/* empty statement */;
#else
printk(KERN_INFO "Unpacking initramfs...\n");
err = unpack_to_rootfs((char *)initrd_start,
initrd_end - initrd_start);
if (err)
printk(KERN_EMERG "Initramfs unpacking failed: %s\n", err);
free_initrd();
#endif
}
flush_delayed_fput();
/*
* Try loading default modules from initramfs. This gives
* us a chance to load before device_initcalls.
*/
load_default_modules();
return 0;
}
rootfs_initcall(populate_rootfs);