linux/init/initramfs.c
Mike Rapoport 899ee4afe5 arm64: use generic free_initrd_mem()
arm64 calls memblock_free() for the initrd area in its implementation of
free_initrd_mem(), but this call has no actual effect that late in the boot
process. By the time initrd is freed, all the reserved memory is managed by
the page allocator and the memblock.reserved is unused, so the only purpose
of the memblock_free() call is to keep track of initrd memory for debugging
and accounting.

Without the memblock_free() call the only difference between arm64 and the
generic versions of free_initrd_mem() is the memory poisoning.

Move memblock_free() call to the generic code, enable it there
for the architectures that define ARCH_KEEP_MEMBLOCK and use the generic
implementation of free_initrd_mem() on arm64.

Tested-by: Anshuman Khandual <anshuman.khandual@arm.com>	#arm64
Reviewed-by: Anshuman Khandual <anshuman.khandual@arm.com>
Acked-by: Will Deacon <will@kernel.org>
Signed-off-by: Mike Rapoport <rppt@linux.ibm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2019-10-16 13:55:25 +01:00

689 lines
14 KiB
C

// SPDX-License-Identifier: GPL-2.0
#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>
#include <linux/memblock.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 = ksys_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, time64_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;
time64_t mtime;
};
static void __init dir_add(const char *name, time64_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 time64_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]; /* breaks in y2106 */
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 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))
ksys_rmdir(path);
else
ksys_unlink(path);
}
}
static int __init maybe_link(void)
{
if (nlink >= 2) {
char *old = find_link(major, minor, ino, mode, collected);
if (old) {
clean_path(collected, 0);
return (ksys_link(old, collected) < 0) ? -1 : 1;
}
}
return 0;
}
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 = ksys_open(collected, openflags, mode);
if (wfd >= 0) {
ksys_fchown(wfd, uid, gid);
ksys_fchmod(wfd, mode);
if (body_len)
ksys_ftruncate(wfd, body_len);
vcollected = kstrdup(collected, GFP_KERNEL);
state = CopyFile;
}
}
} else if (S_ISDIR(mode)) {
ksys_mkdir(collected, mode);
ksys_chown(collected, uid, gid);
ksys_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) {
ksys_mknod(collected, mode, rdev);
ksys_chown(collected, uid, gid);
ksys_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");
ksys_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);
ksys_symlink(collected + N_ALIGN(name_len), collected);
ksys_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 within 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("invalid magic at start of compressed archive");
if (state != Reset)
error("junk at the end of 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);
#ifdef CONFIG_ARCH_HAS_KEEPINITRD
static int __init keepinitrd_setup(char *__unused)
{
do_retain_initrd = 1;
return 1;
}
__setup("keepinitrd", keepinitrd_setup);
#endif
extern char __initramfs_start[];
extern unsigned long __initramfs_size;
#include <linux/initrd.h>
#include <linux/kexec.h>
void __weak free_initrd_mem(unsigned long start, unsigned long end)
{
#ifdef CONFIG_ARCH_KEEP_MEMBLOCK
unsigned long aligned_start = ALIGN_DOWN(start, PAGE_SIZE);
unsigned long aligned_end = ALIGN(end, PAGE_SIZE);
memblock_free(__pa(aligned_start), aligned_end - aligned_start);
#endif
free_reserved_area((void *)start, (void *)end, POISON_FREE_INITMEM,
"initrd");
}
#ifdef CONFIG_KEXEC_CORE
static bool kexec_free_initrd(void)
{
unsigned long crashk_start = (unsigned long)__va(crashk_res.start);
unsigned long crashk_end = (unsigned long)__va(crashk_res.end);
/*
* 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)
return false;
/*
* 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);
return true;
}
#else
static inline bool kexec_free_initrd(void)
{
return false;
}
#endif /* CONFIG_KEXEC_CORE */
#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 = ksys_open("/", O_RDONLY, 0);
WARN_ON(fd < 0);
if (fd < 0)
return;
buf = kzalloc(BUF_SIZE, GFP_KERNEL);
WARN_ON(!buf);
if (!buf) {
ksys_close(fd);
return;
}
dirp = buf;
num = ksys_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))
ksys_rmdir(dirp->d_name);
else
ksys_unlink(dirp->d_name);
}
num -= dirp->d_reclen;
dirp = (void *)dirp + dirp->d_reclen;
}
dirp = buf;
memset(buf, 0, BUF_SIZE);
num = ksys_getdents64(fd, dirp, BUF_SIZE);
}
ksys_close(fd);
kfree(buf);
}
#else
static inline void clean_rootfs(void)
{
}
#endif /* CONFIG_BLK_DEV_RAM */
#ifdef CONFIG_BLK_DEV_RAM
static void __init populate_initrd_image(char *err)
{
ssize_t written;
int fd;
unpack_to_rootfs(__initramfs_start, __initramfs_size);
printk(KERN_INFO "rootfs image is not initramfs (%s); looks like an initrd\n",
err);
fd = ksys_open("/initrd.image", O_WRONLY | O_CREAT, 0700);
if (fd < 0)
return;
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);
ksys_close(fd);
}
#else
static void __init populate_initrd_image(char *err)
{
printk(KERN_EMERG "Initramfs unpacking failed: %s\n", err);
}
#endif /* CONFIG_BLK_DEV_RAM */
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 (!initrd_start || IS_ENABLED(CONFIG_INITRAMFS_FORCE))
goto done;
if (IS_ENABLED(CONFIG_BLK_DEV_RAM))
printk(KERN_INFO "Trying to unpack rootfs image as initramfs...\n");
else
printk(KERN_INFO "Unpacking initramfs...\n");
err = unpack_to_rootfs((char *)initrd_start, initrd_end - initrd_start);
if (err) {
clean_rootfs();
populate_initrd_image(err);
}
done:
/*
* If the initrd region is overlapped with crashkernel reserved region,
* free only memory that is not part of crashkernel region.
*/
if (!do_retain_initrd && initrd_start && !kexec_free_initrd())
free_initrd_mem(initrd_start, initrd_end);
initrd_start = 0;
initrd_end = 0;
flush_delayed_fput();
return 0;
}
rootfs_initcall(populate_rootfs);