From: "Ahmed S. Darwish" <darwish.07@gmail.com> To: "Theodore Y. Ts'o" <tytso@mit.edu> Cc: Linus Torvalds <torvalds@linux-foundation.org>, Andreas Dilger <adilger.kernel@dilger.ca>, Jan Kara <jack@suse.cz>, Ray Strode <rstrode@redhat.com>, William Jon McCann <mccann@jhu.edu>, "Alexander E. Patrakov" <patrakov@gmail.com>, zhangjs <zachary@baishancloud.com>, linux-ext4@vger.kernel.org, lkml <linux-kernel@vger.kernel.org> Subject: Re: Linux 5.3-rc8 Date: Sat, 14 Sep 2019 11:25:09 +0200 Message-ID: <20190914092509.GA1138@darwi-home-pc> (raw) In-Reply-To: <20190912082530.GA27365@mit.edu> On Thu, Sep 12, 2019 at 04:25:30AM -0400, Theodore Y. Ts'o wrote: > On Thu, Sep 12, 2019 at 05:44:21AM +0200, Ahmed S. Darwish wrote: [...] > > > 1. Cutting down the number of bits needed to initialize the CRNG > > to 256 bits (CHACHA20 cipher) > > Does the attach patch (see below) help? > [...] > > diff --git a/drivers/char/random.c b/drivers/char/random.c > index 5d5ea4ce1442..b9b3a5a82abf 100644 > --- a/drivers/char/random.c > +++ b/drivers/char/random.c > @@ -500,7 +500,7 @@ static int crng_init = 0; > #define crng_ready() (likely(crng_init > 1)) > static int crng_init_cnt = 0; > static unsigned long crng_global_init_time = 0; > -#define CRNG_INIT_CNT_THRESH (2*CHACHA_KEY_SIZE) > +#define CRNG_INIT_CNT_THRESH CHACHA_KEY_SIZE > static void _extract_crng(struct crng_state *crng, __u8 out[CHACHA_BLOCK_SIZE]); > static void _crng_backtrack_protect(struct crng_state *crng, > __u8 tmp[CHACHA_BLOCK_SIZE], int used); Unfortunately, it only made the early fast init faster, but didn't fix the normal crng init blockage :-( Here's a trace log, got by applying the patch at [1]. The boot was continued only after typing some random keys after ~30s: # # entries-in-buffer/entries-written: 22/22 #P:8 # # _-----=> irqs-off # / _----=> need-resched # | / _---=> hardirq/softirq # || / _--=> preempt-depth # ||| / delay # TASK-PID CPU# |||| TIMESTAMP FUNCTION # | | | |||| | | <idle>-0 [001] dNh. 0.687088: crng_fast_load: crng threshold = 32 <idle>-0 [001] dNh. 0.687089: crng_fast_load: crng_init_cnt = 0 <idle>-0 [001] dNh. 0.687090: crng_fast_load: crng_init_cnt, now set to 16 <idle>-0 [001] dNh. 0.705208: crng_fast_load: crng threshold = 32 <idle>-0 [001] dNh. 0.705209: crng_fast_load: crng_init_cnt = 16 <idle>-0 [001] dNh. 0.705209: crng_fast_load: crng_init_cnt, now set to 32 <idle>-0 [001] dNh. 0.708048: crng_fast_load: random: fast init done lvm-165 [001] d... 2.417971: urandom_read: random: crng_init_cnt, now set to 0 systemd-random--179 [003] .... 2.495669: wait_for_random_bytes.part.0: wait for randomness dbus-daemon-274 [006] dN.. 3.294331: urandom_read: random: crng_init_cnt, now set to 0 dbus-daemon-274 [006] dN.. 3.316618: urandom_read: random: crng_init_cnt, now set to 0 polkitd-286 [007] dN.. 3.873918: urandom_read: random: crng_init_cnt, now set to 0 polkitd-286 [007] dN.. 3.874303: urandom_read: random: crng_init_cnt, now set to 0 polkitd-286 [007] dN.. 3.874375: urandom_read: random: crng_init_cnt, now set to 0 polkitd-286 [007] d... 3.886204: urandom_read: random: crng_init_cnt, now set to 0 polkitd-286 [007] d... 3.886217: urandom_read: random: crng_init_cnt, now set to 0 polkitd-286 [007] d... 3.888519: urandom_read: random: crng_init_cnt, now set to 0 polkitd-286 [007] d... 3.888529: urandom_read: random: crng_init_cnt, now set to 0 gnome-session-b-321 [006] .... 4.292034: wait_for_random_bytes.part.0: wait for randomness <idle>-0 [002] dNh. 36.784001: crng_reseed: random: crng init done gnome-session-b-321 [006] .... 36.784019: wait_for_random_bytes.part.0: wait done systemd-random--179 [003] .... 36.784051: wait_for_random_bytes.part.0: wait done [1] patch: diff --git a/drivers/char/random.c b/drivers/char/random.c index 5d5ea4ce1442..4a50ee2c230d 100644 --- a/drivers/char/random.c +++ b/drivers/char/random.c @@ -500,7 +500,7 @@ static int crng_init = 0; #define crng_ready() (likely(crng_init > 1)) static int crng_init_cnt = 0; static unsigned long crng_global_init_time = 0; -#define CRNG_INIT_CNT_THRESH (2*CHACHA_KEY_SIZE) +#define CRNG_INIT_CNT_THRESH (CHACHA_KEY_SIZE) static void _extract_crng(struct crng_state *crng, __u8 out[CHACHA_BLOCK_SIZE]); static void _crng_backtrack_protect(struct crng_state *crng, __u8 tmp[CHACHA_BLOCK_SIZE], int used); @@ -931,6 +931,9 @@ static int crng_fast_load(const char *cp, size_t len) unsigned long flags; char *p; + trace_printk("crng threshold = %d\n", CRNG_INIT_CNT_THRESH); + trace_printk("crng_init_cnt = %d\n", crng_init_cnt); + if (!spin_trylock_irqsave(&primary_crng.lock, flags)) return 0; if (crng_init != 0) { @@ -943,11 +946,15 @@ static int crng_fast_load(const char *cp, size_t len) cp++; crng_init_cnt++; len--; } spin_unlock_irqrestore(&primary_crng.lock, flags); + + trace_printk("crng_init_cnt, now set to %d\n", crng_init_cnt); + if (crng_init_cnt >= CRNG_INIT_CNT_THRESH) { invalidate_batched_entropy(); crng_init = 1; wake_up_interruptible(&crng_init_wait); pr_notice("random: fast init done\n"); + trace_printk("random: fast init done\n"); } return 1; } @@ -1033,6 +1040,7 @@ static void crng_reseed(struct crng_state *crng, struct entropy_store *r) process_random_ready_list(); wake_up_interruptible(&crng_init_wait); pr_notice("random: crng init done\n"); + trace_printk("random: crng init done\n"); if (unseeded_warning.missed) { pr_notice("random: %d get_random_xx warning(s) missed " "due to ratelimiting\n", @@ -1743,9 +1751,16 @@ EXPORT_SYMBOL(get_random_bytes); */ int wait_for_random_bytes(void) { + int ret; + if (likely(crng_ready())) return 0; - return wait_event_interruptible(crng_init_wait, crng_ready()); + + trace_printk("wait for randomness\n"); + ret = wait_event_interruptible(crng_init_wait, crng_ready()); + trace_printk("wait done\n"); + + return ret; } EXPORT_SYMBOL(wait_for_random_bytes); @@ -1974,6 +1989,8 @@ urandom_read(struct file *file, char __user *buf, size_t nbytes, loff_t *ppos) current->comm, nbytes); spin_lock_irqsave(&primary_crng.lock, flags); crng_init_cnt = 0; + trace_printk("random: crng_init_cnt, now set to %d\n", + crng_init_cnt); spin_unlock_irqrestore(&primary_crng.lock, flags); } nbytes = min_t(size_t, nbytes, INT_MAX >> (ENTROPY_SHIFT + 3)); thanks, -- darwi http://darwish.chasingpointers.com
next prev parent reply index Thread overview: 211+ messages / expand[flat|nested] mbox.gz Atom feed top [not found] <CAHk-=whBQ+6c-h+htiv6pp8ndtv97+45AH9WvdZougDRM6M4VQ@mail.gmail.com> 2019-09-10 4:21 ` Ahmed S. Darwish 2019-09-10 11:33 ` Linus Torvalds 2019-09-10 12:21 ` Linus Torvalds 2019-09-10 17:33 ` Ahmed S. Darwish 2019-09-10 17:47 ` Reindl Harald 2019-09-10 18:21 ` Linus Torvalds 2019-09-11 16:07 ` Theodore Y. Ts'o 2019-09-11 16:45 ` Linus Torvalds 2019-09-11 17:00 ` Linus Torvalds 2019-09-11 17:36 ` Theodore Y. Ts'o 2019-09-12 3:44 ` Ahmed S. Darwish 2019-09-12 8:25 ` Theodore Y. Ts'o 2019-09-12 11:34 ` Linus Torvalds 2019-09-12 11:58 ` Willy Tarreau 2019-09-14 12:25 ` [PATCH RFC] random: getrandom(2): don't block on non-initialized entropy pool Ahmed S. Darwish 2019-09-14 14:08 ` Alexander E. Patrakov 2019-09-15 5:22 ` [PATCH RFC v2] random: optionally block in getrandom(2) when the CRNG is uninitialized Theodore Y. Ts'o 2019-09-15 8:17 ` [PATCH RFC v3] random: getrandom(2): optionally block when " Ahmed S. Darwish 2019-09-15 8:59 ` Lennart Poettering 2019-09-15 9:30 ` Willy Tarreau 2019-09-15 10:02 ` Ahmed S. Darwish 2019-09-15 10:40 ` Willy Tarreau 2019-09-15 10:55 ` Ahmed S. Darwish 2019-09-15 11:17 ` Willy Tarreau 2019-09-15 17:32 ` [PATCH RFC v2] random: optionally block in getrandom(2) when the " Linus Torvalds 2019-09-15 18:32 ` Willy Tarreau 2019-09-15 18:36 ` Willy Tarreau 2019-09-15 19:08 ` Linus Torvalds 2019-09-15 19:18 ` Willy Tarreau 2019-09-15 19:31 ` Linus Torvalds 2019-09-15 19:54 ` Willy Tarreau 2019-09-15 18:59 ` Linus Torvalds 2019-09-15 19:12 ` Willy Tarreau 2019-09-16 2:45 ` Ahmed S. Darwish 2019-09-16 18:08 ` Lennart Poettering 2019-09-16 19:16 ` Willy Tarreau 2019-09-18 21:15 ` [PATCH RFC v4 0/1] random: WARN on large getrandom() waits and introduce getrandom2() Ahmed S. Darwish 2019-09-18 21:17 ` [PATCH RFC v4 1/1] " Ahmed S. Darwish 2019-09-18 23:57 ` Linus Torvalds 2019-09-19 14:34 ` Theodore Y. Ts'o 2019-09-19 15:20 ` Linus Torvalds 2019-09-19 15:50 ` Linus Torvalds 2019-09-20 13:13 ` Theodore Y. Ts'o 2019-09-19 20:04 ` Linus Torvalds 2019-09-19 20:45 ` Alexander E. Patrakov 2019-09-19 21:47 ` Linus Torvalds 2019-09-19 22:23 ` Alexander E. Patrakov 2019-09-19 23:44 ` Alexander E. Patrakov 2019-09-20 13:16 ` Theodore Y. Ts'o 2019-09-23 11:55 ` David Laight 2019-09-20 13:08 ` Theodore Y. Ts'o 2019-09-20 13:46 ` Ahmed S. Darwish 2019-09-20 14:33 ` Andy Lutomirski 2019-09-20 16:29 ` Linus Torvalds 2019-09-20 17:52 ` Andy Lutomirski 2019-09-20 18:09 ` Linus Torvalds 2019-09-20 18:16 ` Willy Tarreau 2019-09-20 19:12 ` Andy Lutomirski 2019-09-20 19:51 ` Linus Torvalds 2019-09-20 20:11 ` Alexander E. Patrakov 2019-09-20 20:17 ` Matthew Garrett 2019-09-20 20:51 ` Andy Lutomirski 2019-09-20 22:44 ` Linus Torvalds 2019-09-20 23:30 ` Andy Lutomirski 2019-09-21 3:05 ` Willy Tarreau 2019-09-21 6:07 ` Florian Weimer 2019-09-23 18:33 ` Andy Lutomirski 2019-09-26 21:11 ` Ahmed S. Darwish 2019-09-20 18:12 ` Willy Tarreau 2019-09-20 19:22 ` Andy Lutomirski 2019-09-20 19:37 ` Willy Tarreau 2019-09-20 19:52 ` Andy Lutomirski 2019-09-20 20:02 ` Linus Torvalds 2019-09-20 18:15 ` Alexander E. Patrakov 2019-09-20 18:29 ` Andy Lutomirski 2019-09-20 17:26 ` Willy Tarreau 2019-09-20 17:56 ` Ahmed S. Darwish 2019-09-26 20:42 ` [PATCH v5 0/1] random: getrandom(2): warn on large CRNG waits, introduce new flags Ahmed S. Darwish 2019-09-26 20:44 ` [PATCH v5 1/1] " Ahmed S. Darwish 2019-09-26 21:39 ` Andy Lutomirski 2019-09-28 9:30 ` Ahmed S. Darwish 2019-09-14 15:02 ` Linux 5.3-rc8 Ahmed S. Darwish 2019-09-14 16:30 ` Linus Torvalds 2019-09-14 16:35 ` Alexander E. Patrakov 2019-09-14 16:52 ` Linus Torvalds 2019-09-14 17:09 ` Alexander E. Patrakov 2019-09-14 19:19 ` Linus Torvalds 2019-09-15 6:56 ` Lennart Poettering 2019-09-15 7:01 ` Willy Tarreau 2019-09-15 7:05 ` Lennart Poettering 2019-09-15 7:07 ` Willy Tarreau 2019-09-15 8:34 ` Lennart Poettering 2019-09-15 17:02 ` Linus Torvalds 2019-09-16 3:23 ` Theodore Y. Ts'o 2019-09-16 3:40 ` Linus Torvalds 2019-09-16 3:56 ` Linus Torvalds 2019-09-16 17:00 ` Theodore Y. Ts'o 2019-09-16 17:07 ` Linus Torvalds 2019-09-14 21:11 ` Ahmed S. Darwish 2019-09-14 22:05 ` Martin Steigerwald 2019-09-14 22:24 ` Theodore Y. Ts'o 2019-09-14 22:32 ` Linus Torvalds 2019-09-15 1:00 ` Theodore Y. Ts'o 2019-09-15 1:10 ` Linus Torvalds 2019-09-15 2:05 ` Theodore Y. Ts'o 2019-09-15 2:11 ` Linus Torvalds 2019-09-15 6:33 ` Willy Tarreau 2019-09-15 6:53 ` Willy Tarreau 2019-09-15 6:51 ` Lennart Poettering 2019-09-15 7:27 ` Ahmed S. Darwish 2019-09-15 8:48 ` Lennart Poettering 2019-09-15 16:29 ` Linus Torvalds 2019-09-16 1:40 ` Ahmed S. Darwish 2019-09-16 1:48 ` Vito Caputo 2019-09-16 2:49 ` Theodore Y. Ts'o 2019-09-16 4:29 ` Willy Tarreau 2019-09-16 5:02 ` Linus Torvalds 2019-09-16 6:12 ` Willy Tarreau 2019-09-16 16:17 ` Linus Torvalds 2019-09-16 17:21 ` Theodore Y. Ts'o 2019-09-16 17:44 ` Linus Torvalds 2019-09-16 17:55 ` Serge Belyshev 2019-09-16 19:08 ` Willy Tarreau 2019-09-16 23:02 ` Matthew Garrett 2019-09-16 23:05 ` Linus Torvalds 2019-09-16 23:11 ` Matthew Garrett 2019-09-16 23:13 ` Alexander E. Patrakov 2019-09-16 23:15 ` Matthew Garrett 2019-09-16 23:18 ` Linus Torvalds 2019-09-16 23:29 ` Ahmed S. Darwish 2019-09-17 1:05 ` Linus Torvalds 2019-09-17 1:23 ` Matthew Garrett 2019-09-17 1:41 ` Linus Torvalds 2019-09-17 1:46 ` Matthew Garrett 2019-09-17 5:24 ` Willy Tarreau 2019-09-17 7:33 ` Martin Steigerwald 2019-09-17 8:35 ` Willy Tarreau 2019-09-17 8:44 ` Martin Steigerwald 2019-09-17 12:11 ` Theodore Y. Ts'o 2019-09-17 12:30 ` Ahmed S. Darwish 2019-09-17 12:46 ` Alexander E. Patrakov 2019-09-17 12:47 ` Willy Tarreau 2019-09-17 16:08 ` Lennart Poettering 2019-09-17 16:23 ` Linus Torvalds 2019-09-17 16:34 ` Reindl Harald 2019-09-17 17:42 ` Lennart Poettering 2019-09-17 18:01 ` Linus Torvalds 2019-09-17 20:28 ` Martin Steigerwald 2019-09-17 20:52 ` Ahmed S. Darwish 2019-09-17 21:38 ` Martin Steigerwald 2019-09-17 21:52 ` Matthew Garrett 2019-09-17 22:10 ` Martin Steigerwald 2019-09-18 13:53 ` Lennart Poettering 2019-09-19 7:28 ` Martin Steigerwald 2019-09-17 23:08 ` Linus Torvalds 2019-09-18 13:40 ` Lennart Poettering 2019-09-17 20:58 ` Linus Torvalds 2019-09-18 9:33 ` Rasmus Villemoes 2019-09-18 10:16 ` Willy Tarreau 2019-09-18 10:25 ` Alexander E. Patrakov 2019-09-18 10:42 ` Willy Tarreau 2019-09-18 19:31 ` Linus Torvalds 2019-09-18 19:56 ` Eric W. Biederman 2019-09-18 20:13 ` Linus Torvalds 2019-09-18 20:15 ` Alexander E. Patrakov 2019-09-18 20:26 ` Linus Torvalds 2019-09-18 22:12 ` Willy Tarreau 2019-09-27 13:57 ` Lennart Poettering 2019-09-27 15:58 ` Linus Torvalds 2019-09-29 9:05 ` Lennart Poettering 2019-09-17 13:11 ` Alexander E. Patrakov 2019-09-17 13:37 ` Alexander E. Patrakov 2019-09-17 15:57 ` Lennart Poettering 2019-09-17 16:21 ` Willy Tarreau 2019-09-17 17:13 ` Lennart Poettering 2019-09-17 17:29 ` Willy Tarreau 2019-09-17 20:42 ` Martin Steigerwald 2019-09-18 13:38 ` Lennart Poettering 2019-09-18 13:59 ` Alexander E. Patrakov 2019-09-18 14:50 ` Alexander E. Patrakov 2019-09-17 20:36 ` Martin Steigerwald 2019-09-17 16:27 ` Linus Torvalds 2019-09-17 16:34 ` Matthew Garrett 2019-09-17 17:16 ` Willy Tarreau 2019-09-17 17:20 ` Matthew Garrett 2019-09-17 17:23 ` Matthew Garrett 2019-09-17 17:57 ` Willy Tarreau 2019-09-17 16:58 ` Alexander E. Patrakov 2019-09-17 17:30 ` Lennart Poettering 2019-09-17 17:32 ` Willy Tarreau 2019-09-17 17:41 ` Alexander E. Patrakov 2019-09-17 17:28 ` Lennart Poettering 2019-09-17 0:03 ` Matthew Garrett 2019-09-17 0:40 ` Matthew Garrett 2019-09-17 7:15 ` a sane approach to random numbers (was: Re: Linux 5.3-rc8) Martin Steigerwald 2019-09-16 18:00 ` Linux 5.3-rc8 Alexander E. Patrakov 2019-09-16 19:53 ` Ahmed S. Darwish 2019-09-17 15:32 ` Lennart Poettering 2019-09-16 3:31 ` Linus Torvalds 2019-09-23 20:49 ` chaos generating driver was " Pavel Machek 2019-09-14 9:25 ` Ahmed S. Darwish [this message] 2019-09-14 16:27 ` Theodore Y. Ts'o 2019-09-11 21:41 ` Ahmed S. Darwish 2019-09-11 22:37 ` Ahmed S. Darwish 2019-09-16 3:52 ` Herbert Xu 2019-09-16 4:21 ` Linus Torvalds 2019-09-16 4:53 ` Willy Tarreau 2019-09-10 11:56 ` Theodore Y. Ts'o 2019-09-16 10:33 ` Christoph Hellwig 2019-10-03 21:10 ` Jon Masters 2019-10-03 21:31 ` Jon Masters
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