From 57f0f512b273f60d52568b8c6b77e17f5636edc0 Mon Sep 17 00:00:00 2001 From: André Fabian Silva Delgado Date: Wed, 5 Aug 2015 17:04:01 -0300 Subject: Initial import --- init/initramfs.c | 658 +++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 658 insertions(+) create mode 100644 init/initramfs.c (limited to 'init/initramfs.c') diff --git a/init/initramfs.c b/init/initramfs.c new file mode 100644 index 000000000..ad1bd7787 --- /dev/null +++ b/init/initramfs.c @@ -0,0 +1,658 @@ +/* + * 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 +#include +#include +#include +#include +#include +#include +#include +#include +#include + +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 timespec 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 stat st; + + if (!sys_newlstat(path, &st) && (st.st_mode ^ fmode) & S_IFMT) { + if (S_ISDIR(st.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 + +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 +#include + +static void __init free_initrd(void) +{ +#ifdef CONFIG_KEXEC + 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 + /* + * 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 stat st; + int ret; + + ret = sys_newlstat(dirp->d_name, &st); + WARN_ON_ONCE(ret); + if (!ret) { + if (S_ISDIR(st.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) +{ + char *err = unpack_to_rootfs(__initramfs_start, __initramfs_size); + if (err) + panic("%s", err); /* Failed to decompress INTERNAL initramfs */ + if (initrd_start) { +#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: +#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 + /* + * 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); -- cgit v1.2.3-54-g00ecf