Commit a8b8017c authored by Michal Marek's avatar Michal Marek
Browse files

initramfs: Use KBUILD_BUILD_TIMESTAMP for generated entries 



gen_init_cpio gets the current time and uses it for each symlink,
special file, and directory.  Grab the current time once and make it
possible to override it with the KBUILD_BUILD_TIMESTAMP variable for
reproducible builds.

Signed-off-by: default avatarMichal Marek <mmarek@suse.cz>
parent 53e6892c

Documentation/kbuild/kbuild.txt

+2 −1
Original line number Diff line number Diff line
@@ -205,7 +205,8 @@ gcc -W... options for more extensive build-time checking. 
KBUILD_BUILD_TIMESTAMP

--------------------------------------------------

Setting this to a date string overrides the timestamp used in the

UTS_VERSION definition (uname -v in the running kernel). The default value

UTS_VERSION definition (uname -v in the running kernel). The value has to

be a string that can be passed to date -d. The default value

is the output of the date command at one point during build.



KBUILD_BUILD_USER, KBUILD_BUILD_HOST

scripts/gen_initramfs_list.sh

+8 −1
Original line number Diff line number Diff line
@@ -287,8 +287,15 @@ done 
# we are carefull to delete tmp files

if [ ! -z ${output_file} ]; then

	if [ -z ${cpio_file} ]; then

		timestamp=

		if test -n "$KBUILD_BUILD_TIMESTAMP"; then

			timestamp="$(date -d"$KBUILD_BUILD_TIMESTAMP" +%s || :)"

			if test -n "$timestamp"; then

				timestamp="-t $timestamp"

			fi

		fi

		cpio_tfile="$(mktemp ${TMPDIR:-/tmp}/cpiofile.XXXXXX)"

		usr/gen_init_cpio ${cpio_list} > ${cpio_tfile}

		usr/gen_init_cpio $timestamp ${cpio_list} > ${cpio_tfile}

	else

		cpio_tfile=${cpio_file}

	fi

usr/gen_init_cpio.c

+40 −13
Original line number Diff line number Diff line
@@ -22,6 +22,7 @@ 


static unsigned int offset;

static unsigned int ino = 721;

static time_t default_mtime;



struct file_handler {

	const char *type;
@@ -102,7 +103,6 @@ static int cpio_mkslink(const char *name, const char *target, 
			 unsigned int mode, uid_t uid, gid_t gid)

{

	char s[256];

	time_t mtime = time(NULL);



	if (name[0] == '/')

		name++;
@@ -114,7 +114,7 @@ static int cpio_mkslink(const char *name, const char *target, 
		(long) uid,		/* uid */

		(long) gid,		/* gid */

		1,			/* nlink */

		(long) mtime,		/* mtime */

		(long) default_mtime,	/* mtime */

		(unsigned)strlen(target)+1, /* filesize */

		3,			/* major */

		1,			/* minor */
@@ -152,7 +152,6 @@ static int cpio_mkgeneric(const char *name, unsigned int mode, 
		       uid_t uid, gid_t gid)

{

	char s[256];

	time_t mtime = time(NULL);



	if (name[0] == '/')

		name++;
@@ -164,7 +163,7 @@ static int cpio_mkgeneric(const char *name, unsigned int mode, 
		(long) uid,		/* uid */

		(long) gid,		/* gid */

		2,			/* nlink */

		(long) mtime,		/* mtime */

		(long) default_mtime,	/* mtime */

		0,			/* filesize */

		3,			/* major */

		1,			/* minor */
@@ -242,7 +241,6 @@ static int cpio_mknod(const char *name, unsigned int mode, 
		       unsigned int maj, unsigned int min)

{

	char s[256];

	time_t mtime = time(NULL);



	if (dev_type == 'b')

		mode |= S_IFBLK;
@@ -259,7 +257,7 @@ static int cpio_mknod(const char *name, unsigned int mode, 
		(long) uid,		/* uid */

		(long) gid,		/* gid */

		1,			/* nlink */

		(long) mtime,		/* mtime */

		(long) default_mtime,	/* mtime */

		0,			/* filesize */

		3,			/* major */

		1,			/* minor */
@@ -460,7 +458,7 @@ static int cpio_mkfile_line(const char *line) 
static void usage(const char *prog)

{

	fprintf(stderr, "Usage:\n"

		"\t%s <cpio_list>\n"

		"\t%s [-t <timestamp>] <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"
@@ -491,7 +489,11 @@ static void usage(const char *prog) 
		"nod /dev/console 0600 0 0 c 5 1\n"

		"dir /root 0700 0 0\n"

		"dir /sbin 0755 0 0\n"

		"file /sbin/kinit /usr/src/klibc/kinit/kinit 0755 0 0\n",

		"file /sbin/kinit /usr/src/klibc/kinit/kinit 0755 0 0\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",

		prog);

}
@@ -529,17 +531,42 @@ int main (int argc, char *argv[]) 
	char *args, *type;

	int ec = 0;

	int line_nr = 0;

	const char *filename;



	default_mtime = time(NULL);

	while (1) {

		int opt = getopt(argc, argv, "t:h");

		char *invalid;



	if (2 != argc) {

		if (opt == -1)

			break;

		switch (opt) {

		case 't':

			default_mtime = strtol(optarg, &invalid, 10);

			if (!*optarg || *invalid) {

				fprintf(stderr, "Invalid timestamp: %s\n",

						optarg);

				usage(argv[0]);

				exit(1);

			}

			break;

		case 'h':

		case '?':

			usage(argv[0]);

			exit(opt == 'h' ? 0 : 1);

		}

	}



	if (!strcmp(argv[1], "-"))

	if (argc - optind != 1) {

		usage(argv[0]);

		exit(1);

	}

	filename = argv[optind];

	if (!strcmp(filename, "-"))

		cpio_list = stdin;

	else if (! (cpio_list = fopen(argv[1], "r"))) {

	else if (!(cpio_list = fopen(filename, "r"))) {

		fprintf(stderr, "ERROR: unable to open '%s': %s\n\n",

			argv[1], strerror(errno));

			filename, strerror(errno));

		usage(argv[0]);

		exit(1);

	}

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