The branch main has been updated by markj:
URL:
https://cgit.FreeBSD.org/src/commit/?id=95ac5b0e27e9070ba91c28f9a6ecbed743d148cb
commit 95ac5b0e27e9070ba91c28f9a6ecbed743d148cb
Author: Mark Johnston <ma...@freebsd.org>
AuthorDate: 2025-06-26 14:28:14 +0000
Commit: Mark Johnston <ma...@freebsd.org>
CommitDate: 2025-06-26 14:44:01 +0000
mkimg: Add a reproducible mode
mkimg embeds a UUID in the GPT header and uses the current time of day
to generate it, so its output is not reproducible by default. Add a -R
flag to ask it to use a fixed time for UUID generation.
Merge the FreeBSD-specific implementation of osdep_uuidgen() with that
of Linux, as the use of uuidgen(2) is incompatible with reproducible
output mode.
Reviewed by: bnovkov
MFC after: 2 weeks
Sponsored by: The FreeBSD Foundation
Sponsored by: Klara, Inc.
Differential Revision: https://reviews.freebsd.org/D49716
---
usr.bin/mkimg/mkimg.1 | 8 +++++++-
usr.bin/mkimg/mkimg.c | 10 +++++++++-
usr.bin/mkimg/mkimg.h | 3 +++
usr.bin/mkimg/uuid.c | 19 +++++--------------
4 files changed, 24 insertions(+), 16 deletions(-)
diff --git a/usr.bin/mkimg/mkimg.1 b/usr.bin/mkimg/mkimg.1
index 82bbee53a267..f6b151d2d5c7 100644
--- a/usr.bin/mkimg/mkimg.1
+++ b/usr.bin/mkimg/mkimg.1
@@ -22,7 +22,7 @@
.\" (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
.\" THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
.\"
-.Dd March 12, 2024
+.Dd June 25, 2025
.Dt MKIMG 1
.Os
.Sh NAME
@@ -41,6 +41,7 @@
.Op Fl f Ar format
.Op Fl o Ar outfile
.Op Fl a Ar active
+.Op Fl R
.Op Fl v
.Op Fl y
.Op Fl s Ar scheme Op Fl p Ar partition ...
@@ -138,6 +139,11 @@ option is a shorthand to specify the minimum and maximum
capacity at the
same time.
.Pp
The
+.Fl R
+option enables reproducible mode: any timestamps or random identifiers will
+be fixed so as to ensure consistent output.
+.Pp
+The
.Fl v
option increases the level of output that the
.Nm
diff --git a/usr.bin/mkimg/mkimg.c b/usr.bin/mkimg/mkimg.c
index 3cd9b03c06e9..c8872ebb1bc6 100644
--- a/usr.bin/mkimg/mkimg.c
+++ b/usr.bin/mkimg/mkimg.c
@@ -61,6 +61,8 @@ static struct option longopts[] = {
static uint64_t min_capacity = 0;
static uint64_t max_capacity = 0;
+bool reproducible = false;
+
struct partlisthead partlist = TAILQ_HEAD_INITIALIZER(partlist);
u_int nparts = 0;
@@ -561,7 +563,7 @@ main(int argc, char *argv[])
bcfd = -1;
outfd = 1; /* Write to stdout by default */
- while ((c = getopt_long(argc, argv, "a:b:c:C:f:o:p:s:vyH:P:S:T:",
+ while ((c = getopt_long(argc, argv, "a:b:c:C:f:o:p:s:vyH:P:RS:T:",
longopts, NULL)) != -1) {
switch (c) {
case 'a': /* ACTIVE PARTITION, if supported */
@@ -606,6 +608,9 @@ main(int argc, char *argv[])
if (error)
errc(EX_DATAERR, error, "partition");
break;
+ case 'R':
+ reproducible = true;
+ break;
case 's': /* SCHEME */
if (scheme_selected() != NULL)
usage("multiple schemes given");
@@ -675,6 +680,9 @@ main(int argc, char *argv[])
if (max_capacity != 0 && min_capacity > max_capacity)
usage("minimum capacity cannot be larger than the maximum one");
+ if (reproducible)
+ srandom(42);
+
if (secsz > blksz) {
if (blksz != 0)
errx(EX_DATAERR, "the physical block size cannot "
diff --git a/usr.bin/mkimg/mkimg.h b/usr.bin/mkimg/mkimg.h
index e85f77de0ec7..608de458e83c 100644
--- a/usr.bin/mkimg/mkimg.h
+++ b/usr.bin/mkimg/mkimg.h
@@ -29,6 +29,9 @@
#include <sys/queue.h>
#include <sys/types.h>
+#include <stdbool.h>
+
+extern bool reproducible; /* Generate reproducible output. */
struct part {
TAILQ_ENTRY(part) link;
diff --git a/usr.bin/mkimg/uuid.c b/usr.bin/mkimg/uuid.c
index 470d92c76293..f3415a8c1111 100644
--- a/usr.bin/mkimg/uuid.c
+++ b/usr.bin/mkimg/uuid.c
@@ -45,20 +45,9 @@ osdep_uuidgen(mkimg_uuid_t *uuid)
}
#endif /* __APPLE__ */
-#ifdef __FreeBSD__
-#include <sys/uuid.h>
-
-static void
-osdep_uuidgen(mkimg_uuid_t *uuid)
-{
-
- uuidgen((void *)uuid, 1);
-}
-#endif /* __FreeBSD__ */
-
-#ifdef __linux__
+#if defined(__linux__) || defined(__FreeBSD__)
+#include <sys/time.h>
#include <stdlib.h>
-#include <time.h>
static void
osdep_uuidgen(mkimg_uuid_t *uuid)
@@ -68,7 +57,9 @@ osdep_uuidgen(mkimg_uuid_t *uuid)
u_int i;
uint16_t seq;
- if (gettimeofday(&tv, NULL) == -1)
+ if (reproducible)
+ memset(&tv, 0, sizeof(tv));
+ else if (gettimeofday(&tv, NULL) == -1)
abort();
time += (uint64_t)tv.tv_sec * 10000000LL;
