Groups | Search | Server Info | Keyboard shortcuts | Login | Register [http] [https] [nntp] [nntps]

Groups > linux.debian.kernel > #60923

Bug#897572: urandom hang in early boot

From Ben Caradoc-Davies <ben@transient.nz>
Newsgroups linux.debian.bugs.dist, linux.debian.kernel
Subject Bug#897572: urandom hang in early boot
Date 2018-05-08 07:00 +0200
Message-ID <vN2Tf-2GZ-1@gated-at.bofh.it> (permalink)
References (4 earlier) <vMXAe-7Xs-5@gated-at.bofh.it> <vN0eJ-19n-1@gated-at.bofh.it> <vN1Xc-25k-7@gated-at.bofh.it> <vLbR0-2oY-1@gated-at.bofh.it> <vN1Xc-25k-7@gated-at.bofh.it>
Organization linux.* mail to news gateway

Cross-posted to 2 groups.

Show all headers | View raw

On 08/05/18 15:55, Ben Caradoc-Davies wrote:
> If something calls getrandom without GRND_NONBLOCK while crng_init==1 
> (during early boot)
I now have conclusive evidence that this is the cause of the hang. If I 
add a printk:

diff --git a/drivers/char/random.c b/drivers/char/random.c
index cd888d4ee605..b7358cc32f42 100644
--- a/drivers/char/random.c
+++ b/drivers/char/random.c
@@ -2021,6 +2021,9 @@ SYSCALL_DEFINE3(getrandom, char __user *, buf, 
size_t, count,
         if (!crng_ready()) {
                 if (flags & GRND_NONBLOCK)
                         return -EAGAIN;
+               printk(KERN_NOTICE "random: %s: getrandom without "
+                               "GRND_NONBLOCK while crng not ready\n",
+                               current->comm);
                 ret = wait_for_random_bytes();
                 if (unlikely(ret))
                         return ret;

I get these at the console just before the hang:

random: plymouthd: uninitialized urandom read (8 bytes read)
random: plymouthd: uninitialized urandom read (8 bytes read)
random: plymouthd: getrandom without GRND_NONBLOCK while crng not ready

Kind regards,

-- 
Ben Caradoc-Davies <ben@transient.nz>
Director
Transient Software Limited <https://transient.nz/>
New Zealand

Back to linux.debian.kernel | Previous | Next — Previous in thread | Next in thread | Find similar | Unroll thread

Thread

Bug#897572: linux-image-4.16.0-1-amd64 breaks plymouth LUKS prompt (missing Kaby Lake firmware?) Ben Caradoc-Davies <ben@transient.nz> - 2018-05-03 04:10 +0200
  Bug#897572: linux-image-4.16.0-1-amd64 breaks plymouth LUKS prompt Ben Caradoc-Davies <ben@transient.nz> - 2018-05-03 06:50 +0200
  Bug#897572: linux-image-4.16.0-1-amd64 breaks plymouth LUKS prompt Ben Caradoc-Davies <ben@transient.nz> - 2018-05-03 07:30 +0200
  Bug#897572: linux-image-4.16.0-1-amd64 breaks plymouth LUKS prompt Ben Caradoc-Davies <ben@transient.nz> - 2018-05-03 07:40 +0200
    Bug#897572: linux-image-4.16.0-1-amd64 breaks plymouth LUKS prompt Ben Caradoc-Davies <ben@transient.nz> - 2018-05-04 01:40 +0200
    Bug#897572: linux-image-4.16.0-1-amd64 breaks plymouth LUKS prompt Ben Caradoc-Davies <ben@transient.nz> - 2018-05-04 02:00 +0200
  Bug#897572: linux-image-4.16.0-1-amd64 breaks plymouth LUKS prompt Ben Hutchings <ben@decadent.org.uk> - 2018-05-05 21:10 +0200
    Bug#897572: linux-image-4.16.0-1-amd64 breaks plymouth LUKS prompt Ben Caradoc-Davies <ben@transient.nz> - 2018-05-06 02:40 +0200
      Bug#897572: linux-image-4.16.0-1-amd64 breaks plymouth LUKS prompt Ben Hutchings <ben@decadent.org.uk> - 2018-05-06 05:10 +0200
    Bug#897572: linux-image-4.16.0-1-amd64 breaks plymouth LUKS prompt Laurent Bigonville <bigon@debian.org> - 2018-05-06 17:30 +0200
      Bug#897572: linux-image-4.16.0-1-amd64 breaks plymouth LUKS prompt Ben Hutchings <ben@decadent.org.uk> - 2018-05-06 19:50 +0200
  Bug#897572: plymouth: long delay before splashscreen with kernel 4.16 Ben Caradoc-Davies <ben@transient.nz> - 2018-05-06 03:10 +0200
    Bug#897572: plymouth: long delay before splashscreen with kernel 4.16 at46 <at46n@t-online.de> - 2018-05-06 08:50 +0200
      Bug#897572: plymouth: long delay before splashscreen with kernel 4.16 Ben Caradoc-Davies <ben@transient.nz> - 2018-05-07 02:50 +0200
  Bug#897572:  Eric Mill <eric@konklone.com> - 2018-05-06 19:30 +0200
  Bug#897572: [PATCH] Revert "random: fix crng_ready() test" Ben Caradoc-Davies <ben@transient.nz> - 2018-05-07 05:10 +0200
    Bug#897572: [PATCH] Revert "random: fix crng_ready() test" "Theodore Y. Ts'o" <tytso@mit.edu> - 2018-05-07 06:20 +0200
  Bug#897572: [PATCH] Revert "random: fix crng_ready() test" Ben Caradoc-Davies <ben@transient.nz> - 2018-05-07 05:50 +0200
    Bug#897572: [PATCH] Revert "random: fix crng_ready() test" "Theodore Y. Ts'o" <tytso@mit.edu> - 2018-05-07 06:20 +0200
  Bug#897572: urandom hang in early boot Laurent Bigonville <bigon@debian.org> - 2018-05-07 19:40 +0200
    Bug#897572: urandom hang in early boot Ben Caradoc-Davies <ben@transient.nz> - 2018-05-08 01:20 +0200
      Bug#897572: urandom hang in early boot Ben Hutchings <ben@decadent.org.uk> - 2018-05-08 04:10 +0200
        Bug#897572: urandom hang in early boot Ben Caradoc-Davies <ben@transient.nz> - 2018-05-08 06:00 +0200
          Bug#897572: urandom hang in early boot Ben Caradoc-Davies <ben@transient.nz> - 2018-05-08 07:00 +0200
  Bug#897572: urandom hang in early boot Bjørn Mork <bjorn@mork.no> - 2018-05-08 13:40 +0200
    Bug#897572: urandom hang in early boot Yves-Alexis Perez <corsac@debian.org> - 2018-05-09 18:40 +0200
  Bug#897572: getrandom hang in early boot prevents plymouth passphrase entry Esokrates <esokrarkose@gmail.com> - 2018-05-09 11:00 +0200
  Bug#897572: [PATCH] Copy fontconfig .uuid files to avoid getrandom hang in early boot Ben Caradoc-Davies <ben@transient.nz> - 2018-05-10 02:00 +0200

csiph-web