Re: [PATCH v28 11/12] LRNG - add interface for gathering of raw entropy

On 1/15/20 10:43 PM, Stephan Mueller wrote:

Am Donnerstag, 16. Januar 2020, 01:18:18 CET schrieb Randy Dunlap:

Hi Randy,

quoted

On 1/15/20 2:35 AM, Stephan Müller wrote:

quoted

CC: "Eric W. Biederman" <redacted>
CC: "Alexander E. Patrakov" <redacted>
CC: "Ahmed S. Darwish" <redacted>
CC: "Theodore Y. Ts'o" <tytso@mit.edu>
CC: Willy Tarreau <w@1wt.eu>
CC: Matthew Garrett <mjg59@srcf.ucam.org>
CC: Vito Caputo <redacted>
CC: Andreas Dilger <adilger.kernel@dilger.ca>
CC: Jan Kara <jack@suse.cz>
CC: Ray Strode <redacted>
CC: William Jon McCann <redacted>
CC: zhangjs <redacted>
CC: Andy Lutomirski <luto@kernel.org>
CC: Florian Weimer <redacted>
CC: Lennart Poettering <redacted>
CC: Nicolai Stange <redacted>
Reviewed-by: Roman Drahtmueller <redacted>
Tested-by: Roman Drahtmüller <redacted>
Tested-by: Marcelo Henrique Cerri <redacted>
Tested-by: Neil Horman <redacted>
Signed-off-by: Stephan Mueller <redacted>
---

 drivers/char/lrng/Kconfig        |  16 ++
 drivers/char/lrng/Makefile       |   1 +
 drivers/char/lrng/lrng_testing.c | 271 +++++++++++++++++++++++++++++++
 3 files changed, 288 insertions(+)
 create mode 100644 drivers/char/lrng/lrng_testing.c

diff --git a/drivers/char/lrng/lrng_testing.c

b/drivers/char/lrng/lrng_testing.c new file mode 100644
index 000000000000..0e287eccd622

--- /dev/null
+++ b/drivers/char/lrng/lrng_testing.c

@@ -0,0 +1,271 @@
+// SPDX-License-Identifier: GPL-2.0 OR BSD-2-Clause
+/*
+ * Linux Random Number Generator (LRNG) Raw entropy collection tool
+ *
+ * Copyright (C) 2019 - 2020, Stephan Mueller <smueller@chronox.de>
+ */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include <linux/atomic.h>
+#include <linux/bug.h>
+#include <linux/debugfs.h>
+#include <linux/module.h>
+#include <linux/sched.h>
+#include <linux/sched/signal.h>
+#include <linux/slab.h>
+#include <linux/string.h>
+#include <linux/types.h>
+#include <linux/uaccess.h>
+#include <linux/workqueue.h>
+#include <asm/errno.h>
+
+#include "lrng_internal.h"
+
+#define LRNG_TESTING_RINGBUFFER_SIZE	1024
+#define LRNG_TESTING_RINGBUFFER_MASK	(LRNG_TESTING_RINGBUFFER_SIZE - 1)
+
+static u32 lrng_testing_rb[LRNG_TESTING_RINGBUFFER_SIZE];
+static u32 lrng_rb_reader = 0;
+static u32 lrng_rb_writer = 0;
+static atomic_t lrng_testing_enabled = ATOMIC_INIT(0);
+
+static DECLARE_WAIT_QUEUE_HEAD(lrng_raw_read_wait);
+static DEFINE_SPINLOCK(lrng_raw_lock);
+
+/*
+ * 0 ==> No boot test, gathering of runtime data allowed
+ * 1 ==> Boot test enabled and ready for collecting data, gathering

runtime + *	 data is disabled
+ * 2 ==> Boot test completed and disabled, gathering of runtime data is
+ *	 disabled
+ */
+static u32 boot_test = 0;
+module_param(boot_test, uint, 0644);
+MODULE_PARM_DESC(boot_test, "Enable gathering boot time entropy of the
first" +			    " entropy events");

One line for the string, please.

may I ask the question whether this should be done for all lines with printk 
statements? As checkpatch.pl will complain if you have lines larger than 80 
chars and complains about line-broken printk statements, I am always unsure 
which way to go.

All printk statements in the patch series have line-broken printk statements.

It's for grep-ability of the strings.
grepping for partial strings would work as is, but then one would need to know
what partial string to search for.

-- 
~Randy