From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from metis.ext.pengutronix.de ([2001:67c:670:201:290:27ff:fe1d:cc33]) by bombadil.infradead.org with esmtps (Exim 4.92 #3 (Red Hat Linux)) id 1hmwyl-0004H8-IK for barebox@lists.infradead.org; Mon, 15 Jul 2019 09:09:04 +0000 From: Sascha Hauer Date: Mon, 15 Jul 2019 11:09:00 +0200 Message-Id: <20190715090900.19123-1-s.hauer@pengutronix.de> MIME-Version: 1.0 List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "barebox" Errors-To: barebox-bounces+u.kleine-koenig=pengutronix.de@lists.infradead.org Subject: [PATCH] ubiformat: improve generation of UBI image sequence To: Barebox List The UBI ec_hdr has an image_seq field. During attaching UBI expects that its value is the same for all eraseblocks. The value should be changed with every ubiformat and is used to detect half written images. In barebox we use a pseudo random number generated with rand() for this value. The ubiformat command calls srand(get_time_ns()) to initialize the pseudo random numbber generator. This is done in the option parser, so when ubiformat() is called directly (from fastboot for example) the pseudo random number generator is not initialized and we get the same values after every barebox restart. This patch moves the pseudo random number generator initialization to the place where the numbers are generated. Also use random32() rather than rand() to generate 32bit values rather than 15bit values (0 - RAND_MAX). Signed-off-by: Sascha Hauer --- commands/ubiformat.c | 1 - common/ubiformat.c | 6 ++++-- 2 files changed, 4 insertions(+), 3 deletions(-) diff --git a/commands/ubiformat.c b/commands/ubiformat.c index a88672d6c2..7537e6b567 100644 --- a/commands/ubiformat.c +++ b/commands/ubiformat.c @@ -58,7 +58,6 @@ static int parse_opt(int argc, char *argv[], struct ubiformat_args *args, char **node) { - srand(get_time_ns()); memset(args, 0, sizeof(*args)); while (1) { diff --git a/common/ubiformat.c b/common/ubiformat.c index 1968bd98f8..fe02270b78 100644 --- a/common/ubiformat.c +++ b/common/ubiformat.c @@ -481,8 +481,10 @@ int ubiformat(struct mtd_info *mtd, struct ubiformat_args *args) if (!args->ubi_ver) args->ubi_ver = 1; - if (!args->image_seq) - args->image_seq = rand(); + if (!args->image_seq) { + srand(get_time_ns()); + args->image_seq = random32(); + } if (!is_power_of_2(mtd->writesize)) { errmsg("min. I/O size is %d, but should be power of 2", -- 2.20.1 _______________________________________________ barebox mailing list barebox@lists.infradead.org http://lists.infradead.org/mailman/listinfo/barebox