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-rw-r--r--init/initramfs.c655
1 files changed, 655 insertions, 0 deletions
diff --git a/init/initramfs.c b/init/initramfs.c
new file mode 100644
index 000000000..dab8d6345
--- /dev/null
+++ b/init/initramfs.c
@@ -0,0 +1,655 @@
+// 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>
+
+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 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 || !initrd_start)
+ 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 = 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);
+}
+#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)
+ goto done;
+
+ 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 = ksys_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);
+
+ ksys_close(fd);
+ }
+ 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);
+#endif
+ }
+ free_initrd();
+ 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);
generated by cgit v1.2.3 (git 2.39.1) at 2024-11-27 13:49:03 +0000