4.14-stable patches

added patches:
	random-avoid-reading-two-cache-lines-on-irq-randomness.patch

diff --git a/queue-4.14/random-avoid-reading-two-cache-lines-on-irq-randomness.patch b/queue-4.14/random-avoid-reading-two-cache-lines-on-irq-randomness.patch
new file mode 100644 (file)
index 0000000..9ffb51d
--- /dev/null
+++ b/queue-4.14/random-avoid-reading-two-cache-lines-on-irq-randomness.patch
@@ -0,0 +1,38 @@
+From 9ee0507e896b45af6d65408c77815800bce30008 Mon Sep 17 00:00:00 2001
+From: "Jason A. Donenfeld" <Jason@zx2c4.com>
+Date: Thu, 22 Sep 2022 18:46:04 +0200
+Subject: random: avoid reading two cache lines on irq randomness
+
+From: Jason A. Donenfeld <Jason@zx2c4.com>
+
+commit 9ee0507e896b45af6d65408c77815800bce30008 upstream.
+
+In order to avoid reading and dirtying two cache lines on every IRQ,
+move the work_struct to the bottom of the fast_pool struct. add_
+interrupt_randomness() always touches .pool and .count, which are
+currently split, because .mix pushes everything down. Instead, move .mix
+to the bottom, so that .pool and .count are always in the first cache
+line, since .mix is only accessed when the pool is full.
+
+Fixes: 58340f8e952b ("random: defer fast pool mixing to worker")
+Reviewed-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
+Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
+Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+---
+ drivers/char/random.c |    2 +-
+ 1 file changed, 1 insertion(+), 1 deletion(-)
+
+--- a/drivers/char/random.c
++++ b/drivers/char/random.c
+@@ -890,10 +890,10 @@ void __init add_bootloader_randomness(co
+ }
+ 
+ struct fast_pool {
+-      struct work_struct mix;
+       unsigned long pool[4];
+       unsigned long last;
+       unsigned int count;
++      struct work_struct mix;
+ };
+ 
+ static DEFINE_PER_CPU(struct fast_pool, irq_randomness) = {

diff --git a/queue-4.14/series b/queue-4.14/series
index afcf3c76ceef048c88b9c2e2bd9d605040d5ca66..ade71bd75c58fae423ebd70ef12fd99304346707 100644 (file)
--- a/queue-4.14/series
+++ b/queue-4.14/series
@@ -42,3 +42,4 @@ alsa-hda-fix-position-reporting-on-poulsbo.patch
 scsi-stex-properly-zero-out-the-passthrough-command-structure.patch
 usb-serial-qcserial-add-new-usb-id-for-dell-branded-em7455.patch
 random-restore-o_nonblock-support.patch
+random-avoid-reading-two-cache-lines-on-irq-randomness.patch