9687fd9101
On a system with low memory extracting the initramfs may fail. If this happens the user gets "Failed to execute /init" instead of an initramfs error. Check return value of sys_write and call error() when the write was incomplete or failed. Signed-off-by: David Engraf <david.engraf@sysgo.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
658 lines
14 KiB
C
658 lines
14 KiB
C
/*
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* Many of the syscalls used in this file expect some of the arguments
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* to be __user pointers not __kernel pointers. To limit the sparse
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* noise, turn off sparse checking for this file.
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*/
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#ifdef __CHECKER__
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#undef __CHECKER__
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#warning "Sparse checking disabled for this file"
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#endif
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#include <linux/init.h>
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#include <linux/fs.h>
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#include <linux/slab.h>
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#include <linux/types.h>
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#include <linux/fcntl.h>
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#include <linux/delay.h>
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#include <linux/string.h>
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#include <linux/dirent.h>
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#include <linux/syscalls.h>
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#include <linux/utime.h>
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static ssize_t __init xwrite(int fd, const char *p, size_t count)
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{
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ssize_t out = 0;
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/* sys_write only can write MAX_RW_COUNT aka 2G-4K bytes at most */
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while (count) {
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ssize_t rv = sys_write(fd, p, count);
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if (rv < 0) {
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if (rv == -EINTR || rv == -EAGAIN)
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continue;
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return out ? out : rv;
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} else if (rv == 0)
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break;
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p += rv;
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out += rv;
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count -= rv;
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}
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return out;
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}
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static __initdata char *message;
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static void __init error(char *x)
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{
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if (!message)
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message = x;
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}
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/* link hash */
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#define N_ALIGN(len) ((((len) + 1) & ~3) + 2)
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static __initdata struct hash {
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int ino, minor, major;
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umode_t mode;
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struct hash *next;
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char name[N_ALIGN(PATH_MAX)];
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} *head[32];
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static inline int hash(int major, int minor, int ino)
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{
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unsigned long tmp = ino + minor + (major << 3);
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tmp += tmp >> 5;
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return tmp & 31;
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}
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static char __init *find_link(int major, int minor, int ino,
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umode_t mode, char *name)
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{
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struct hash **p, *q;
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for (p = head + hash(major, minor, ino); *p; p = &(*p)->next) {
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if ((*p)->ino != ino)
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continue;
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if ((*p)->minor != minor)
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continue;
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if ((*p)->major != major)
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continue;
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if (((*p)->mode ^ mode) & S_IFMT)
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continue;
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return (*p)->name;
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}
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q = kmalloc(sizeof(struct hash), GFP_KERNEL);
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if (!q)
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panic("can't allocate link hash entry");
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q->major = major;
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q->minor = minor;
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q->ino = ino;
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q->mode = mode;
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strcpy(q->name, name);
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q->next = NULL;
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*p = q;
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return NULL;
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}
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static void __init free_hash(void)
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{
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struct hash **p, *q;
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for (p = head; p < head + 32; p++) {
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while (*p) {
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q = *p;
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*p = q->next;
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kfree(q);
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}
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}
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}
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static long __init do_utime(char *filename, time_t mtime)
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{
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struct timespec t[2];
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t[0].tv_sec = mtime;
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t[0].tv_nsec = 0;
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t[1].tv_sec = mtime;
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t[1].tv_nsec = 0;
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return do_utimes(AT_FDCWD, filename, t, AT_SYMLINK_NOFOLLOW);
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}
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static __initdata LIST_HEAD(dir_list);
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struct dir_entry {
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struct list_head list;
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char *name;
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time_t mtime;
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};
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static void __init dir_add(const char *name, time_t mtime)
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{
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struct dir_entry *de = kmalloc(sizeof(struct dir_entry), GFP_KERNEL);
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if (!de)
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panic("can't allocate dir_entry buffer");
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INIT_LIST_HEAD(&de->list);
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de->name = kstrdup(name, GFP_KERNEL);
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de->mtime = mtime;
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list_add(&de->list, &dir_list);
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}
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static void __init dir_utime(void)
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{
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struct dir_entry *de, *tmp;
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list_for_each_entry_safe(de, tmp, &dir_list, list) {
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list_del(&de->list);
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do_utime(de->name, de->mtime);
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kfree(de->name);
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kfree(de);
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}
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}
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static __initdata time_t mtime;
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/* cpio header parsing */
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static __initdata unsigned long ino, major, minor, nlink;
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static __initdata umode_t mode;
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static __initdata unsigned long body_len, name_len;
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static __initdata uid_t uid;
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static __initdata gid_t gid;
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static __initdata unsigned rdev;
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static void __init parse_header(char *s)
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{
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unsigned long parsed[12];
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char buf[9];
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int i;
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buf[8] = '\0';
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for (i = 0, s += 6; i < 12; i++, s += 8) {
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memcpy(buf, s, 8);
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parsed[i] = simple_strtoul(buf, NULL, 16);
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}
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ino = parsed[0];
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mode = parsed[1];
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uid = parsed[2];
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gid = parsed[3];
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nlink = parsed[4];
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mtime = parsed[5];
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body_len = parsed[6];
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major = parsed[7];
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minor = parsed[8];
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rdev = new_encode_dev(MKDEV(parsed[9], parsed[10]));
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name_len = parsed[11];
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}
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/* FSM */
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static __initdata enum state {
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Start,
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Collect,
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GotHeader,
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SkipIt,
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GotName,
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CopyFile,
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GotSymlink,
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Reset
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} state, next_state;
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static __initdata char *victim;
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static unsigned long count __initdata;
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static __initdata loff_t this_header, next_header;
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static inline void __init eat(unsigned n)
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{
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victim += n;
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this_header += n;
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count -= n;
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}
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static __initdata char *vcollected;
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static __initdata char *collected;
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static long remains __initdata;
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static __initdata char *collect;
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static void __init read_into(char *buf, unsigned size, enum state next)
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{
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if (count >= size) {
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collected = victim;
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eat(size);
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state = next;
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} else {
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collect = collected = buf;
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remains = size;
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next_state = next;
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state = Collect;
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}
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}
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static __initdata char *header_buf, *symlink_buf, *name_buf;
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static int __init do_start(void)
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{
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read_into(header_buf, 110, GotHeader);
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return 0;
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}
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static int __init do_collect(void)
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{
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unsigned long n = remains;
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if (count < n)
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n = count;
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memcpy(collect, victim, n);
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eat(n);
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collect += n;
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if ((remains -= n) != 0)
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return 1;
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state = next_state;
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return 0;
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}
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static int __init do_header(void)
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{
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if (memcmp(collected, "070707", 6)==0) {
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error("incorrect cpio method used: use -H newc option");
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return 1;
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}
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if (memcmp(collected, "070701", 6)) {
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error("no cpio magic");
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return 1;
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}
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parse_header(collected);
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next_header = this_header + N_ALIGN(name_len) + body_len;
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next_header = (next_header + 3) & ~3;
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state = SkipIt;
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if (name_len <= 0 || name_len > PATH_MAX)
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return 0;
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if (S_ISLNK(mode)) {
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if (body_len > PATH_MAX)
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return 0;
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collect = collected = symlink_buf;
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remains = N_ALIGN(name_len) + body_len;
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next_state = GotSymlink;
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state = Collect;
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return 0;
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}
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if (S_ISREG(mode) || !body_len)
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read_into(name_buf, N_ALIGN(name_len), GotName);
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return 0;
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}
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static int __init do_skip(void)
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{
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if (this_header + count < next_header) {
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eat(count);
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return 1;
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} else {
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eat(next_header - this_header);
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state = next_state;
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return 0;
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}
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}
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static int __init do_reset(void)
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{
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while(count && *victim == '\0')
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eat(1);
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if (count && (this_header & 3))
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error("broken padding");
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return 1;
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}
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static int __init maybe_link(void)
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{
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if (nlink >= 2) {
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char *old = find_link(major, minor, ino, mode, collected);
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if (old)
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return (sys_link(old, collected) < 0) ? -1 : 1;
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}
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return 0;
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}
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static void __init clean_path(char *path, umode_t mode)
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{
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struct stat st;
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if (!sys_newlstat(path, &st) && (st.st_mode^mode) & S_IFMT) {
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if (S_ISDIR(st.st_mode))
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sys_rmdir(path);
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else
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sys_unlink(path);
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}
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}
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static __initdata int wfd;
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static int __init do_name(void)
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{
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state = SkipIt;
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next_state = Reset;
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if (strcmp(collected, "TRAILER!!!") == 0) {
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free_hash();
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return 0;
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}
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clean_path(collected, mode);
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if (S_ISREG(mode)) {
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int ml = maybe_link();
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if (ml >= 0) {
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int openflags = O_WRONLY|O_CREAT;
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if (ml != 1)
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openflags |= O_TRUNC;
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wfd = sys_open(collected, openflags, mode);
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if (wfd >= 0) {
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sys_fchown(wfd, uid, gid);
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sys_fchmod(wfd, mode);
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if (body_len)
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sys_ftruncate(wfd, body_len);
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vcollected = kstrdup(collected, GFP_KERNEL);
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state = CopyFile;
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}
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}
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} else if (S_ISDIR(mode)) {
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sys_mkdir(collected, mode);
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sys_chown(collected, uid, gid);
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sys_chmod(collected, mode);
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dir_add(collected, mtime);
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} else if (S_ISBLK(mode) || S_ISCHR(mode) ||
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S_ISFIFO(mode) || S_ISSOCK(mode)) {
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if (maybe_link() == 0) {
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sys_mknod(collected, mode, rdev);
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sys_chown(collected, uid, gid);
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sys_chmod(collected, mode);
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do_utime(collected, mtime);
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}
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}
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return 0;
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}
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static int __init do_copy(void)
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{
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if (count >= body_len) {
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if (xwrite(wfd, victim, body_len) != body_len)
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error("write error");
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sys_close(wfd);
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do_utime(vcollected, mtime);
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kfree(vcollected);
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eat(body_len);
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state = SkipIt;
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return 0;
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} else {
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if (xwrite(wfd, victim, count) != count)
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error("write error");
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body_len -= count;
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eat(count);
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return 1;
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}
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}
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static int __init do_symlink(void)
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{
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collected[N_ALIGN(name_len) + body_len] = '\0';
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clean_path(collected, 0);
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sys_symlink(collected + N_ALIGN(name_len), collected);
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sys_lchown(collected, uid, gid);
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do_utime(collected, mtime);
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state = SkipIt;
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next_state = Reset;
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return 0;
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}
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static __initdata int (*actions[])(void) = {
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[Start] = do_start,
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[Collect] = do_collect,
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[GotHeader] = do_header,
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[SkipIt] = do_skip,
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[GotName] = do_name,
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[CopyFile] = do_copy,
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[GotSymlink] = do_symlink,
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[Reset] = do_reset,
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};
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static long __init write_buffer(char *buf, unsigned long len)
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{
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count = len;
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victim = buf;
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while (!actions[state]())
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;
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return len - count;
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}
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static long __init flush_buffer(void *bufv, unsigned long len)
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{
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char *buf = (char *) bufv;
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long written;
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long origLen = len;
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if (message)
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return -1;
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while ((written = write_buffer(buf, len)) < len && !message) {
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char c = buf[written];
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if (c == '0') {
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buf += written;
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len -= written;
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state = Start;
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} else if (c == 0) {
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buf += written;
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len -= written;
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state = Reset;
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} else
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error("junk in compressed archive");
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}
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return origLen;
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}
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static unsigned long my_inptr; /* index of next byte to be processed in inbuf */
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#include <linux/decompress/generic.h>
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static char * __init unpack_to_rootfs(char *buf, unsigned long len)
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{
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long written;
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decompress_fn decompress;
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const char *compress_name;
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static __initdata char msg_buf[64];
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header_buf = kmalloc(110, GFP_KERNEL);
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symlink_buf = kmalloc(PATH_MAX + N_ALIGN(PATH_MAX) + 1, GFP_KERNEL);
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name_buf = kmalloc(N_ALIGN(PATH_MAX), GFP_KERNEL);
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if (!header_buf || !symlink_buf || !name_buf)
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panic("can't allocate buffers");
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state = Start;
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this_header = 0;
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message = NULL;
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while (!message && len) {
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loff_t saved_offset = this_header;
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if (*buf == '0' && !(this_header & 3)) {
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state = Start;
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written = write_buffer(buf, len);
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buf += written;
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len -= written;
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continue;
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}
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if (!*buf) {
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buf++;
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len--;
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this_header++;
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continue;
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}
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this_header = 0;
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decompress = decompress_method(buf, len, &compress_name);
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pr_debug("Detected %s compressed data\n", compress_name);
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if (decompress) {
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int res = decompress(buf, len, NULL, flush_buffer, NULL,
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&my_inptr, error);
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if (res)
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error("decompressor failed");
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} else if (compress_name) {
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if (!message) {
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snprintf(msg_buf, sizeof msg_buf,
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"compression method %s not configured",
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compress_name);
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message = msg_buf;
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}
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} else
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error("junk in compressed archive");
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if (state != Reset)
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error("junk in compressed archive");
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this_header = saved_offset + my_inptr;
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buf += my_inptr;
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len -= my_inptr;
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}
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dir_utime();
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kfree(name_buf);
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kfree(symlink_buf);
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kfree(header_buf);
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return message;
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}
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static int __initdata do_retain_initrd;
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static int __init retain_initrd_param(char *str)
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{
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if (*str)
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return 0;
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do_retain_initrd = 1;
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return 1;
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}
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__setup("retain_initrd", retain_initrd_param);
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extern char __initramfs_start[];
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extern unsigned long __initramfs_size;
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#include <linux/initrd.h>
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#include <linux/kexec.h>
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static void __init free_initrd(void)
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{
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#ifdef CONFIG_KEXEC
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unsigned long crashk_start = (unsigned long)__va(crashk_res.start);
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unsigned long crashk_end = (unsigned long)__va(crashk_res.end);
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#endif
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if (do_retain_initrd)
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goto skip;
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#ifdef CONFIG_KEXEC
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/*
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* If the initrd region is overlapped with crashkernel reserved region,
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* free only memory that is not part of crashkernel region.
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*/
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if (initrd_start < crashk_end && initrd_end > crashk_start) {
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/*
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* Initialize initrd memory region since the kexec boot does
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* not do.
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*/
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memset((void *)initrd_start, 0, initrd_end - initrd_start);
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if (initrd_start < crashk_start)
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free_initrd_mem(initrd_start, crashk_start);
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if (initrd_end > crashk_end)
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free_initrd_mem(crashk_end, initrd_end);
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} else
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#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);
|