linux/init/initramfs.c

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13 KiB
C
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#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>
initramfs: add option to preserve mtime from initramfs cpio images When unpacking the cpio into the initramfs, mtimes are not preserved by default. This patch adds an INITRAMFS_PRESERVE_MTIME option that allows mtimes stored in the cpio image to be used when constructing the initramfs. For embedded applications that run exclusively out of the initramfs, this is invaluable: When building embedded application initramfs images, its nice to know when the files were actually created during the build process - that makes it easier to see what files were modified when so we can compare the files that are being used on the image with the files used during the build process. This might help (for example) to determine if the target system has all the updated files you expect to see w/o having to check MD5s etc. In our environment, the whole system runs off the initramfs partition, and seeing the modified times of the shared libraries (for example) helps us find bugs that may have been introduced by the build system incorrectly propogating outdated shared libraries into the image. Similarly, many of the initializion/configuration files in /etc might be dynamically built by the build system, and knowing when they were modified helps us sanity check whether the target system has the "latest" files etc. Finally, we might use last modified times to determine whether a hot fix should be applied or not to the running ramfs. Signed-off-by: Nye Liu <nyet@nyet.org> Cc: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-10-16 13:01:40 +08:00
#include <linux/utime.h>
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;
mode_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,
mode_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);
}
}
}
initramfs: add option to preserve mtime from initramfs cpio images When unpacking the cpio into the initramfs, mtimes are not preserved by default. This patch adds an INITRAMFS_PRESERVE_MTIME option that allows mtimes stored in the cpio image to be used when constructing the initramfs. For embedded applications that run exclusively out of the initramfs, this is invaluable: When building embedded application initramfs images, its nice to know when the files were actually created during the build process - that makes it easier to see what files were modified when so we can compare the files that are being used on the image with the files used during the build process. This might help (for example) to determine if the target system has all the updated files you expect to see w/o having to check MD5s etc. In our environment, the whole system runs off the initramfs partition, and seeing the modified times of the shared libraries (for example) helps us find bugs that may have been introduced by the build system incorrectly propogating outdated shared libraries into the image. Similarly, many of the initializion/configuration files in /etc might be dynamically built by the build system, and knowing when they were modified helps us sanity check whether the target system has the "latest" files etc. Finally, we might use last modified times to determine whether a hot fix should be applied or not to the running ramfs. Signed-off-by: Nye Liu <nyet@nyet.org> Cc: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-10-16 13:01:40 +08:00
static long __init do_utime(char __user *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 mode_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];
initramfs: add option to preserve mtime from initramfs cpio images When unpacking the cpio into the initramfs, mtimes are not preserved by default. This patch adds an INITRAMFS_PRESERVE_MTIME option that allows mtimes stored in the cpio image to be used when constructing the initramfs. For embedded applications that run exclusively out of the initramfs, this is invaluable: When building embedded application initramfs images, its nice to know when the files were actually created during the build process - that makes it easier to see what files were modified when so we can compare the files that are being used on the image with the files used during the build process. This might help (for example) to determine if the target system has all the updated files you expect to see w/o having to check MD5s etc. In our environment, the whole system runs off the initramfs partition, and seeing the modified times of the shared libraries (for example) helps us find bugs that may have been introduced by the build system incorrectly propogating outdated shared libraries into the image. Similarly, many of the initializion/configuration files in /etc might be dynamically built by the build system, and knowing when they were modified helps us sanity check whether the target system has the "latest" files etc. Finally, we might use last modified times to determine whether a hot fix should be applied or not to the running ramfs. Signed-off-by: Nye Liu <nyet@nyet.org> Cc: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-10-16 13:01:40 +08:00
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 __initdata unsigned count;
static __initdata loff_t this_header, next_header;
static inline void __init eat(unsigned n)
{
victim += n;
this_header += n;
count -= n;
}
initramfs: add option to preserve mtime from initramfs cpio images When unpacking the cpio into the initramfs, mtimes are not preserved by default. This patch adds an INITRAMFS_PRESERVE_MTIME option that allows mtimes stored in the cpio image to be used when constructing the initramfs. For embedded applications that run exclusively out of the initramfs, this is invaluable: When building embedded application initramfs images, its nice to know when the files were actually created during the build process - that makes it easier to see what files were modified when so we can compare the files that are being used on the image with the files used during the build process. This might help (for example) to determine if the target system has all the updated files you expect to see w/o having to check MD5s etc. In our environment, the whole system runs off the initramfs partition, and seeing the modified times of the shared libraries (for example) helps us find bugs that may have been introduced by the build system incorrectly propogating outdated shared libraries into the image. Similarly, many of the initializion/configuration files in /etc might be dynamically built by the build system, and knowing when they were modified helps us sanity check whether the target system has the "latest" files etc. Finally, we might use last modified times to determine whether a hot fix should be applied or not to the running ramfs. Signed-off-by: Nye Liu <nyet@nyet.org> Cc: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-10-16 13:01:40 +08:00
static __initdata char *vcollected;
static __initdata char *collected;
static __initdata int remains;
static __initdata char *collect;
static void __init read_into(char *buf, unsigned size, enum state next)
{
if (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 n = remains;
if (count < n)
n = 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 + count < next_header) {
eat(count);
return 1;
} else {
eat(next_header - this_header);
state = next_state;
return 0;
}
}
static int __init do_reset(void)
{
while(count && *victim == '\0')
eat(1);
if (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, mode_t mode)
{
struct stat st;
if (!sys_newlstat(path, &st) && (st.st_mode^mode) & 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);
initramfs: add option to preserve mtime from initramfs cpio images When unpacking the cpio into the initramfs, mtimes are not preserved by default. This patch adds an INITRAMFS_PRESERVE_MTIME option that allows mtimes stored in the cpio image to be used when constructing the initramfs. For embedded applications that run exclusively out of the initramfs, this is invaluable: When building embedded application initramfs images, its nice to know when the files were actually created during the build process - that makes it easier to see what files were modified when so we can compare the files that are being used on the image with the files used during the build process. This might help (for example) to determine if the target system has all the updated files you expect to see w/o having to check MD5s etc. In our environment, the whole system runs off the initramfs partition, and seeing the modified times of the shared libraries (for example) helps us find bugs that may have been introduced by the build system incorrectly propogating outdated shared libraries into the image. Similarly, many of the initializion/configuration files in /etc might be dynamically built by the build system, and knowing when they were modified helps us sanity check whether the target system has the "latest" files etc. Finally, we might use last modified times to determine whether a hot fix should be applied or not to the running ramfs. Signed-off-by: Nye Liu <nyet@nyet.org> Cc: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-10-16 13:01:40 +08:00
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);
initramfs: add option to preserve mtime from initramfs cpio images When unpacking the cpio into the initramfs, mtimes are not preserved by default. This patch adds an INITRAMFS_PRESERVE_MTIME option that allows mtimes stored in the cpio image to be used when constructing the initramfs. For embedded applications that run exclusively out of the initramfs, this is invaluable: When building embedded application initramfs images, its nice to know when the files were actually created during the build process - that makes it easier to see what files were modified when so we can compare the files that are being used on the image with the files used during the build process. This might help (for example) to determine if the target system has all the updated files you expect to see w/o having to check MD5s etc. In our environment, the whole system runs off the initramfs partition, and seeing the modified times of the shared libraries (for example) helps us find bugs that may have been introduced by the build system incorrectly propogating outdated shared libraries into the image. Similarly, many of the initializion/configuration files in /etc might be dynamically built by the build system, and knowing when they were modified helps us sanity check whether the target system has the "latest" files etc. Finally, we might use last modified times to determine whether a hot fix should be applied or not to the running ramfs. Signed-off-by: Nye Liu <nyet@nyet.org> Cc: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-10-16 13:01:40 +08:00
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);
initramfs: add option to preserve mtime from initramfs cpio images When unpacking the cpio into the initramfs, mtimes are not preserved by default. This patch adds an INITRAMFS_PRESERVE_MTIME option that allows mtimes stored in the cpio image to be used when constructing the initramfs. For embedded applications that run exclusively out of the initramfs, this is invaluable: When building embedded application initramfs images, its nice to know when the files were actually created during the build process - that makes it easier to see what files were modified when so we can compare the files that are being used on the image with the files used during the build process. This might help (for example) to determine if the target system has all the updated files you expect to see w/o having to check MD5s etc. In our environment, the whole system runs off the initramfs partition, and seeing the modified times of the shared libraries (for example) helps us find bugs that may have been introduced by the build system incorrectly propogating outdated shared libraries into the image. Similarly, many of the initializion/configuration files in /etc might be dynamically built by the build system, and knowing when they were modified helps us sanity check whether the target system has the "latest" files etc. Finally, we might use last modified times to determine whether a hot fix should be applied or not to the running ramfs. Signed-off-by: Nye Liu <nyet@nyet.org> Cc: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-10-16 13:01:40 +08:00
do_utime(collected, mtime);
}
}
return 0;
}
static int __init do_copy(void)
{
if (count >= body_len) {
sys_write(wfd, victim, body_len);
sys_close(wfd);
initramfs: add option to preserve mtime from initramfs cpio images When unpacking the cpio into the initramfs, mtimes are not preserved by default. This patch adds an INITRAMFS_PRESERVE_MTIME option that allows mtimes stored in the cpio image to be used when constructing the initramfs. For embedded applications that run exclusively out of the initramfs, this is invaluable: When building embedded application initramfs images, its nice to know when the files were actually created during the build process - that makes it easier to see what files were modified when so we can compare the files that are being used on the image with the files used during the build process. This might help (for example) to determine if the target system has all the updated files you expect to see w/o having to check MD5s etc. In our environment, the whole system runs off the initramfs partition, and seeing the modified times of the shared libraries (for example) helps us find bugs that may have been introduced by the build system incorrectly propogating outdated shared libraries into the image. Similarly, many of the initializion/configuration files in /etc might be dynamically built by the build system, and knowing when they were modified helps us sanity check whether the target system has the "latest" files etc. Finally, we might use last modified times to determine whether a hot fix should be applied or not to the running ramfs. Signed-off-by: Nye Liu <nyet@nyet.org> Cc: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-10-16 13:01:40 +08:00
do_utime(vcollected, mtime);
kfree(vcollected);
eat(body_len);
state = SkipIt;
return 0;
} else {
sys_write(wfd, victim, count);
body_len -= count;
eat(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);
initramfs: add option to preserve mtime from initramfs cpio images When unpacking the cpio into the initramfs, mtimes are not preserved by default. This patch adds an INITRAMFS_PRESERVE_MTIME option that allows mtimes stored in the cpio image to be used when constructing the initramfs. For embedded applications that run exclusively out of the initramfs, this is invaluable: When building embedded application initramfs images, its nice to know when the files were actually created during the build process - that makes it easier to see what files were modified when so we can compare the files that are being used on the image with the files used during the build process. This might help (for example) to determine if the target system has all the updated files you expect to see w/o having to check MD5s etc. In our environment, the whole system runs off the initramfs partition, and seeing the modified times of the shared libraries (for example) helps us find bugs that may have been introduced by the build system incorrectly propogating outdated shared libraries into the image. Similarly, many of the initializion/configuration files in /etc might be dynamically built by the build system, and knowing when they were modified helps us sanity check whether the target system has the "latest" files etc. Finally, we might use last modified times to determine whether a hot fix should be applied or not to the running ramfs. Signed-off-by: Nye Liu <nyet@nyet.org> Cc: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-10-16 13:01:40 +08:00
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 int __init write_buffer(char *buf, unsigned len)
{
count = len;
victim = buf;
while (!actions[state]())
;
return len - count;
}
static int __init flush_buffer(void *bufv, unsigned len)
{
char *buf = (char *) bufv;
int written;
int 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 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 len)
{
int written, res;
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);
if (decompress) {
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;
}
initramfs: add option to preserve mtime from initramfs cpio images When unpacking the cpio into the initramfs, mtimes are not preserved by default. This patch adds an INITRAMFS_PRESERVE_MTIME option that allows mtimes stored in the cpio image to be used when constructing the initramfs. For embedded applications that run exclusively out of the initramfs, this is invaluable: When building embedded application initramfs images, its nice to know when the files were actually created during the build process - that makes it easier to see what files were modified when so we can compare the files that are being used on the image with the files used during the build process. This might help (for example) to determine if the target system has all the updated files you expect to see w/o having to check MD5s etc. In our environment, the whole system runs off the initramfs partition, and seeing the modified times of the shared libraries (for example) helps us find bugs that may have been introduced by the build system incorrectly propogating outdated shared libraries into the image. Similarly, many of the initializion/configuration files in /etc might be dynamically built by the build system, and knowing when they were modified helps us sanity check whether the target system has the "latest" files etc. Finally, we might use last modified times to determine whether a hot fix should be applied or not to the running ramfs. Signed-off-by: Nye Liu <nyet@nyet.org> Cc: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-10-16 13:01:40 +08:00
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);
initramfs: fix initramfs size calculation The size of a built-in initramfs is calculated in init/initramfs.c by "__initramfs_end - __initramfs_start". Those symbols are defined in the linker script include/asm-generic/vmlinux.lds.h: #define INIT_RAM_FS \ . = ALIGN(PAGE_SIZE); \ VMLINUX_SYMBOL(__initramfs_start) = .; \ *(.init.ramfs) \ VMLINUX_SYMBOL(__initramfs_end) = .; If the initramfs file has an odd number of bytes, the "__initramfs_end" symbol points to an odd address, for example, the symbols in the System.map might look like: 0000000000572000 T __initramfs_start 00000000005bcd05 T __initramfs_end <-- odd address At least on s390 this causes a problem: Certain s390 instructions, especially instructions for loading addresses (larl) or branch addresses must be on even addresses. The compiler loads the symbol addresses with the "larl" instruction. This instruction sets the last bit to 0 and, therefore, for odd size files, the calculated size is one byte less than it should be: 0000000000540a9c <populate_rootfs>: 540a9c: eb cf f0 78 00 24 stmg %r12,%r15,120(%r15), 540aa2: c0 10 00 01 8a af larl %r1,572000 <__initramfs_start> 540aa8: c0 c0 00 03 e1 2e larl %r12,5bcd04 <initramfs_end> (Instead of 5bcd05) ... 540abe: 1b c1 sr %r12,%r1 To fix the problem, this patch introduces the global variable __initramfs_size, which is calculated in the "usr/initramfs_data.S" file. The populate_rootfs() function can then use the start marker of the .init.ramfs section and the value of __initramfs_size for loading the initramfs. Because the start marker and size is sufficient, the __initramfs_end symbol is no longer needed and is removed. Signed-off-by: Michael Holzheu <holzheu@linux.vnet.ibm.com> Signed-off-by: Hendrik Brueckner <brueckner@linux.vnet.ibm.com> Reviewed-by: WANG Cong <xiyou.wangcong@gmail.com> Acked-by: Michal Marek <mmarek@suse.cz> Acked-by: "H. Peter Anvin" <hpa@zytor.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Michal Marek <mmarek@suse.cz>
2010-09-18 06:24:11 +08:00
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
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((const char __user __force *) "/", 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)
{
initramfs: fix initramfs size calculation The size of a built-in initramfs is calculated in init/initramfs.c by "__initramfs_end - __initramfs_start". Those symbols are defined in the linker script include/asm-generic/vmlinux.lds.h: #define INIT_RAM_FS \ . = ALIGN(PAGE_SIZE); \ VMLINUX_SYMBOL(__initramfs_start) = .; \ *(.init.ramfs) \ VMLINUX_SYMBOL(__initramfs_end) = .; If the initramfs file has an odd number of bytes, the "__initramfs_end" symbol points to an odd address, for example, the symbols in the System.map might look like: 0000000000572000 T __initramfs_start 00000000005bcd05 T __initramfs_end <-- odd address At least on s390 this causes a problem: Certain s390 instructions, especially instructions for loading addresses (larl) or branch addresses must be on even addresses. The compiler loads the symbol addresses with the "larl" instruction. This instruction sets the last bit to 0 and, therefore, for odd size files, the calculated size is one byte less than it should be: 0000000000540a9c <populate_rootfs>: 540a9c: eb cf f0 78 00 24 stmg %r12,%r15,120(%r15), 540aa2: c0 10 00 01 8a af larl %r1,572000 <__initramfs_start> 540aa8: c0 c0 00 03 e1 2e larl %r12,5bcd04 <initramfs_end> (Instead of 5bcd05) ... 540abe: 1b c1 sr %r12,%r1 To fix the problem, this patch introduces the global variable __initramfs_size, which is calculated in the "usr/initramfs_data.S" file. The populate_rootfs() function can then use the start marker of the .init.ramfs section and the value of __initramfs_size for loading the initramfs. Because the start marker and size is sufficient, the __initramfs_end symbol is no longer needed and is removed. Signed-off-by: Michael Holzheu <holzheu@linux.vnet.ibm.com> Signed-off-by: Hendrik Brueckner <brueckner@linux.vnet.ibm.com> Reviewed-by: WANG Cong <xiyou.wangcong@gmail.com> Acked-by: Michal Marek <mmarek@suse.cz> Acked-by: "H. Peter Anvin" <hpa@zytor.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Michal Marek <mmarek@suse.cz>
2010-09-18 06:24:11 +08:00
char *err = unpack_to_rootfs(__initramfs_start, __initramfs_size);
if (err)
panic(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();
return 0;
} else {
clean_rootfs();
initramfs: fix initramfs size calculation The size of a built-in initramfs is calculated in init/initramfs.c by "__initramfs_end - __initramfs_start". Those symbols are defined in the linker script include/asm-generic/vmlinux.lds.h: #define INIT_RAM_FS \ . = ALIGN(PAGE_SIZE); \ VMLINUX_SYMBOL(__initramfs_start) = .; \ *(.init.ramfs) \ VMLINUX_SYMBOL(__initramfs_end) = .; If the initramfs file has an odd number of bytes, the "__initramfs_end" symbol points to an odd address, for example, the symbols in the System.map might look like: 0000000000572000 T __initramfs_start 00000000005bcd05 T __initramfs_end <-- odd address At least on s390 this causes a problem: Certain s390 instructions, especially instructions for loading addresses (larl) or branch addresses must be on even addresses. The compiler loads the symbol addresses with the "larl" instruction. This instruction sets the last bit to 0 and, therefore, for odd size files, the calculated size is one byte less than it should be: 0000000000540a9c <populate_rootfs>: 540a9c: eb cf f0 78 00 24 stmg %r12,%r15,120(%r15), 540aa2: c0 10 00 01 8a af larl %r1,572000 <__initramfs_start> 540aa8: c0 c0 00 03 e1 2e larl %r12,5bcd04 <initramfs_end> (Instead of 5bcd05) ... 540abe: 1b c1 sr %r12,%r1 To fix the problem, this patch introduces the global variable __initramfs_size, which is calculated in the "usr/initramfs_data.S" file. The populate_rootfs() function can then use the start marker of the .init.ramfs section and the value of __initramfs_size for loading the initramfs. Because the start marker and size is sufficient, the __initramfs_end symbol is no longer needed and is removed. Signed-off-by: Michael Holzheu <holzheu@linux.vnet.ibm.com> Signed-off-by: Hendrik Brueckner <brueckner@linux.vnet.ibm.com> Reviewed-by: WANG Cong <xiyou.wangcong@gmail.com> Acked-by: Michal Marek <mmarek@suse.cz> Acked-by: "H. Peter Anvin" <hpa@zytor.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Michal Marek <mmarek@suse.cz>
2010-09-18 06:24:11 +08:00
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((const char __user __force *) "/initrd.image",
O_WRONLY|O_CREAT, 0700);
if (fd >= 0) {
sys_write(fd, (char *)initrd_start,
initrd_end - initrd_start);
sys_close(fd);
free_initrd();
}
#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
}
return 0;
}
rootfs_initcall(populate_rootfs);