mail archive of the barebox mailing list
 help / color / mirror / Atom feed
From: Ahmad Fatoum <a.fatoum@pengutronix.de>
To: barebox@lists.infradead.org
Cc: Ahmad Fatoum <a.fatoum@pengutronix.de>
Subject: [PATCH 1/2] hwrng: dev-random: always use /dev/urandom
Date: Mon, 21 Oct 2019 14:20:46 +0200	[thread overview]
Message-ID: <20191021122047.12204-1-a.fatoum@pengutronix.de> (raw)

/dev/random can block long after boot time. It seems there's a consensus
that /dev/urandom is safe to use except for very early boot, which isn't
when barebox sandbox is usually run. To make the HWRNG more useful,
always use /dev/urandom.

Signed-off-by: Ahmad Fatoum <a.fatoum@pengutronix.de>
---
 arch/sandbox/board/dev-random.c                | 7 +------
 arch/sandbox/mach-sandbox/include/mach/linux.h | 1 -
 drivers/hw_random/Kconfig                      | 6 +++---
 3 files changed, 4 insertions(+), 10 deletions(-)

diff --git a/arch/sandbox/board/dev-random.c b/arch/sandbox/board/dev-random.c
index f65e5ef6e5ed..60295e9fced2 100644
--- a/arch/sandbox/board/dev-random.c
+++ b/arch/sandbox/board/dev-random.c
@@ -4,10 +4,6 @@
 devrandom_t *devrandom_init(void) {
 	devrandom_t *fds = xzalloc(sizeof(*fds));
 
-	fds->randomfd = linux_open("/dev/random", false);
-	if (fds->randomfd < 0)
-		return ERR_PTR(-EPERM);
-
 	fds->urandomfd = linux_open("/dev/urandom", false);
 	if (fds->urandomfd < 0)
 		return ERR_PTR(-EPERM);
@@ -17,8 +13,7 @@ devrandom_t *devrandom_init(void) {
 
 int devrandom_read(devrandom_t *devrandom, void *buf, size_t len, int wait)
 {
-	if (wait)
-		return linux_read(devrandom->randomfd, buf, len);
+	(void)wait; /* /dev/urandom won't block */
 
 	return linux_read(devrandom->urandomfd, buf, len);
 }
diff --git a/arch/sandbox/mach-sandbox/include/mach/linux.h b/arch/sandbox/mach-sandbox/include/mach/linux.h
index 1e64d41c6a5e..9759a376ecb3 100644
--- a/arch/sandbox/mach-sandbox/include/mach/linux.h
+++ b/arch/sandbox/mach-sandbox/include/mach/linux.h
@@ -52,7 +52,6 @@ int barebox_libftdi1_update(struct ft2232_bitbang *ftbb);
 void barebox_libftdi1_close(void);
 
 typedef struct {
-	int randomfd;
 	int urandomfd;
 } devrandom_t;
 devrandom_t *devrandom_init(void);
diff --git a/drivers/hw_random/Kconfig b/drivers/hw_random/Kconfig
index c57928204d30..242a7ef27828 100644
--- a/drivers/hw_random/Kconfig
+++ b/drivers/hw_random/Kconfig
@@ -15,11 +15,11 @@ config HWRNG_MXC_RNGC
 	  Generator hardware found on some Freescale i.MX processors.
 
 config HWRNG_DEV_RANDOM
-	tristate "Linux /dev/random and /dev/urandom RNG"
+	tristate "Linux /dev/urandom RNG"
 	depends on SANDBOX
 	default y
 	help
-	  This driver allows use of the host provided /dev/random
-	  and /dev/urandom as barebox HWRNGs.
+	  This driver allows use of the host provided /dev/urandom
+	  as barebox HWRNGs.
 
 endif
-- 
2.23.0


_______________________________________________
barebox mailing list
barebox@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/barebox

             reply	other threads:[~2019-10-21 12:20 UTC|newest]

Thread overview: 3+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-10-21 12:20 Ahmad Fatoum [this message]
2019-10-21 12:20 ` [PATCH 2/2] commands: passwd: suggest sandbox for offline password generation Ahmad Fatoum
2019-10-23  7:07 ` [PATCH 1/2] hwrng: dev-random: always use /dev/urandom Sascha Hauer

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20191021122047.12204-1-a.fatoum@pengutronix.de \
    --to=a.fatoum@pengutronix.de \
    --cc=barebox@lists.infradead.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body. 
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox