Documentation/driver-api/early-userspace/buffer-format.rst includes the
specification for checksum-enabled cpio archives. Implement support for
this format in gen_init_cpio via a new '-c' parameter.
Link: https://lkml.kernel.org/r/20220404093429.27570-6-ddiss@suse.de
Signed-off-by: David Disseldorp <ddiss@suse.de>
Suggested-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Christian Brauner <christian.brauner@ubuntu.com>
Cc: Martin Wilck <mwilck@suse.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
// SPDX-License-Identifier: GPL-2.0
#include <stdio.h>
#include <stdlib.h>
// SPDX-License-Identifier: GPL-2.0
#include <stdio.h>
#include <stdlib.h>
+#include <stdint.h>
+#include <stdbool.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <string.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <string.h>
static unsigned int offset;
static unsigned int ino = 721;
static time_t default_mtime;
static unsigned int offset;
static unsigned int ino = 721;
static time_t default_mtime;
+static bool do_csum = false;
struct file_handler {
const char *type;
struct file_handler {
const char *type;
sprintf(s, "%s%08X%08X%08lX%08lX%08X%08lX"
"%08X%08X%08X%08X%08X%08X%08X",
sprintf(s, "%s%08X%08X%08lX%08lX%08X%08lX"
"%08X%08X%08X%08X%08X%08X%08X",
+ do_csum ? "070702" : "070701", /* magic */
0, /* ino */
0, /* mode */
(long) 0, /* uid */
0, /* ino */
0, /* mode */
(long) 0, /* uid */
name++;
sprintf(s,"%s%08X%08X%08lX%08lX%08X%08lX"
"%08X%08X%08X%08X%08X%08X%08X",
name++;
sprintf(s,"%s%08X%08X%08lX%08lX%08X%08lX"
"%08X%08X%08X%08X%08X%08X%08X",
+ do_csum ? "070702" : "070701", /* magic */
ino++, /* ino */
S_IFLNK | mode, /* mode */
(long) uid, /* uid */
ino++, /* ino */
S_IFLNK | mode, /* mode */
(long) uid, /* uid */
name++;
sprintf(s,"%s%08X%08X%08lX%08lX%08X%08lX"
"%08X%08X%08X%08X%08X%08X%08X",
name++;
sprintf(s,"%s%08X%08X%08lX%08lX%08X%08lX"
"%08X%08X%08X%08X%08X%08X%08X",
+ do_csum ? "070702" : "070701", /* magic */
ino++, /* ino */
mode, /* mode */
(long) uid, /* uid */
ino++, /* ino */
mode, /* mode */
(long) uid, /* uid */
name++;
sprintf(s,"%s%08X%08X%08lX%08lX%08X%08lX"
"%08X%08X%08X%08X%08X%08X%08X",
name++;
sprintf(s,"%s%08X%08X%08lX%08lX%08X%08lX"
"%08X%08X%08X%08X%08X%08X%08X",
+ do_csum ? "070702" : "070701", /* magic */
ino++, /* ino */
mode, /* mode */
(long) uid, /* uid */
ino++, /* ino */
mode, /* mode */
(long) uid, /* uid */
+static int cpio_mkfile_csum(int fd, unsigned long size, uint32_t *csum)
+{
+ while (size) {
+ unsigned char filebuf[65536];
+ ssize_t this_read;
+ size_t i, this_size = MIN(size, sizeof(filebuf));
+
+ this_read = read(fd, filebuf, this_size);
+ if (this_read <= 0 || this_read > this_size)
+ return -1;
+
+ for (i = 0; i < this_read; i++)
+ *csum += filebuf[i];
+
+ size -= this_read;
+ }
+ /* seek back to the start for data segment I/O */
+ if (lseek(fd, 0, SEEK_SET) < 0)
+ return -1;
+
+ return 0;
+}
+
static int cpio_mkfile(const char *name, const char *location,
unsigned int mode, uid_t uid, gid_t gid,
unsigned int nlinks)
static int cpio_mkfile(const char *name, const char *location,
unsigned int mode, uid_t uid, gid_t gid,
unsigned int nlinks)
int rc = -1;
int namesize;
unsigned int i;
int rc = -1;
int namesize;
unsigned int i;
+ if (do_csum && cpio_mkfile_csum(file, buf.st_size, &csum) < 0) {
+ fprintf(stderr, "Failed to checksum file %s\n", location);
+ goto error;
+ }
+
size = 0;
for (i = 1; i <= nlinks; i++) {
/* data goes on last link */
size = 0;
for (i = 1; i <= nlinks; i++) {
/* data goes on last link */
namesize = strlen(name) + 1;
sprintf(s,"%s%08X%08X%08lX%08lX%08X%08lX"
"%08lX%08X%08X%08X%08X%08X%08X",
namesize = strlen(name) + 1;
sprintf(s,"%s%08X%08X%08lX%08lX%08X%08lX"
"%08lX%08X%08X%08X%08X%08X%08X",
+ do_csum ? "070702" : "070701", /* magic */
ino, /* ino */
mode, /* mode */
(long) uid, /* uid */
ino, /* ino */
mode, /* mode */
(long) uid, /* uid */
0, /* rmajor */
0, /* rminor */
namesize, /* namesize */
0, /* rmajor */
0, /* rminor */
namesize, /* namesize */
+ size ? csum : 0); /* chksum */
push_hdr(s);
push_string(name);
push_pad();
push_hdr(s);
push_string(name);
push_pad();
static void usage(const char *prog)
{
fprintf(stderr, "Usage:\n"
static void usage(const char *prog)
{
fprintf(stderr, "Usage:\n"
- "\t%s [-t <timestamp>] <cpio_list>\n"
+ "\t%s [-t <timestamp>] [-c] <cpio_list>\n"
"\n"
"<cpio_list> is a file containing newline separated entries that\n"
"describe the files to be included in the initramfs archive:\n"
"\n"
"<cpio_list> is a file containing newline separated entries that\n"
"describe the files to be included in the initramfs archive:\n"
"\n"
"<timestamp> is time in seconds since Epoch that will be used\n"
"as mtime for symlinks, special files and directories. The default\n"
"\n"
"<timestamp> is time in seconds since Epoch that will be used\n"
"as mtime for symlinks, special files and directories. The default\n"
- "is to use the current time for these entries.\n",
+ "is to use the current time for these entries.\n"
+ "-c: calculate and store 32-bit checksums for file data.\n",
default_mtime = time(NULL);
while (1) {
default_mtime = time(NULL);
while (1) {
- int opt = getopt(argc, argv, "t:h");
+ int opt = getopt(argc, argv, "t:ch");
char *invalid;
if (opt == -1)
char *invalid;
if (opt == -1)
+ case 'c':
+ do_csum = true;
+ break;
case 'h':
case '?':
usage(argv[0]);
case 'h':
case '?':
usage(argv[0]);