From b22da3d8526a935aa31e086e63f60ff3246cb61c Mon Sep 17 00:00:00 2001
From: hc <hc@nodka.com>
Date: Sat, 09 Dec 2023 07:24:11 +0000
Subject: [PATCH] add stmac read mac form eeprom
---
kernel/drivers/char/hw_random/core.c | 74 ++++++++++++++++++++++++------------
1 files changed, 49 insertions(+), 25 deletions(-)
diff --git a/kernel/drivers/char/hw_random/core.c b/kernel/drivers/char/hw_random/core.c
index 7716fc4..5749998 100644
--- a/kernel/drivers/char/hw_random/core.c
+++ b/kernel/drivers/char/hw_random/core.c
@@ -4,7 +4,7 @@
* Copyright 2006 Michael Buesch <m@bues.ch>
* Copyright 2005 (c) MontaVista Software, Inc.
*
- * Please read Documentation/hw_random.txt for details on use.
+ * Please read Documentation/admin-guide/hw_random.rst for details on use.
*
* This software may be used and distributed according to the terms
* of the GNU General Public License, incorporated herein by reference.
@@ -15,6 +15,7 @@
#include <linux/err.h>
#include <linux/fs.h>
#include <linux/hw_random.h>
+#include <linux/random.h>
#include <linux/kernel.h>
#include <linux/kthread.h>
#include <linux/sched/signal.h>
@@ -44,10 +45,10 @@
module_param(current_quality, ushort, 0644);
MODULE_PARM_DESC(current_quality,
- "current hwrng entropy estimation per mill");
+ "current hwrng entropy estimation per 1024 bits of input");
module_param(default_quality, ushort, 0644);
MODULE_PARM_DESC(default_quality,
- "default entropy content of hwrng per mill");
+ "default entropy content of hwrng per 1024 bits of input");
static void drop_current_rng(void);
static int hwrng_init(struct hwrng *rng);
@@ -111,6 +112,14 @@
}
/* Returns ERR_PTR(), NULL or refcounted hwrng */
+static struct hwrng *get_current_rng_nolock(void)
+{
+ if (current_rng)
+ kref_get(¤t_rng->ref);
+
+ return current_rng;
+}
+
static struct hwrng *get_current_rng(void)
{
struct hwrng *rng;
@@ -118,9 +127,7 @@
if (mutex_lock_interruptible(&rng_mutex))
return ERR_PTR(-ERESTARTSYS);
- rng = current_rng;
- if (rng)
- kref_get(&rng->ref);
+ rng = get_current_rng_nolock();
mutex_unlock(&rng_mutex);
return rng;
@@ -155,8 +162,6 @@
reinit_completion(&rng->cleanup_done);
skip_init:
- add_early_randomness(rng);
-
current_quality = rng->quality ? : default_quality;
if (current_quality > 1024)
current_quality = 1024;
@@ -320,12 +325,13 @@
const char *buf, size_t len)
{
int err = -ENODEV;
- struct hwrng *rng;
+ struct hwrng *rng, *old_rng, *new_rng;
err = mutex_lock_interruptible(&rng_mutex);
if (err)
return -ERESTARTSYS;
+ old_rng = current_rng;
if (sysfs_streq(buf, "")) {
err = enable_best_rng();
} else {
@@ -337,8 +343,14 @@
}
}
}
-
+ new_rng = get_current_rng_nolock();
mutex_unlock(&rng_mutex);
+
+ if (new_rng) {
+ if (new_rng != old_rng)
+ add_early_randomness(new_rng);
+ put_rng(new_rng);
+ }
return err ? : len;
}
@@ -457,13 +469,15 @@
int hwrng_register(struct hwrng *rng)
{
int err = -EINVAL;
- struct hwrng *old_rng, *tmp;
+ struct hwrng *tmp;
struct list_head *rng_list_ptr;
+ bool is_new_current = false;
if (!rng->name || (!rng->data_read && !rng->read))
goto out;
mutex_lock(&rng_mutex);
+
/* Must not register two RNGs with the same name. */
err = -EEXIST;
list_for_each_entry(tmp, &rng_list, list) {
@@ -482,10 +496,8 @@
}
list_add_tail(&rng->list, rng_list_ptr);
- old_rng = current_rng;
- err = 0;
- if (!old_rng ||
- (!cur_rng_set_by_user && rng->quality > old_rng->quality)) {
+ if (!current_rng ||
+ (!cur_rng_set_by_user && rng->quality > current_rng->quality)) {
/*
* Set new rng as current as the new rng source
* provides better entropy quality and was not
@@ -494,19 +506,26 @@
err = set_current_rng(rng);
if (err)
goto out_unlock;
+ /* to use current_rng in add_early_randomness() we need
+ * to take a ref
+ */
+ is_new_current = true;
+ kref_get(&rng->ref);
}
-
- if (old_rng && !rng->init) {
+ mutex_unlock(&rng_mutex);
+ if (is_new_current || !rng->init) {
/*
* Use a new device's input to add some randomness to
* the system. If this rng device isn't going to be
* used right away, its init function hasn't been
- * called yet; so only use the randomness from devices
- * that don't need an init callback.
+ * called yet by set_current_rng(); so only use the
+ * randomness from devices that don't need an init callback
*/
add_early_randomness(rng);
}
-
+ if (is_new_current)
+ put_rng(rng);
+ return 0;
out_unlock:
mutex_unlock(&rng_mutex);
out:
@@ -516,10 +535,12 @@
void hwrng_unregister(struct hwrng *rng)
{
+ struct hwrng *old_rng, *new_rng;
int err;
mutex_lock(&rng_mutex);
+ old_rng = current_rng;
list_del(&rng->list);
if (current_rng == rng) {
err = enable_best_rng();
@@ -529,12 +550,19 @@
}
}
+ new_rng = get_current_rng_nolock();
if (list_empty(&rng_list)) {
mutex_unlock(&rng_mutex);
if (hwrng_fill)
kthread_stop(hwrng_fill);
} else
mutex_unlock(&rng_mutex);
+
+ if (new_rng) {
+ if (old_rng != new_rng)
+ add_early_randomness(new_rng);
+ put_rng(new_rng);
+ }
wait_for_completion(&rng->cleanup_done);
}
@@ -584,7 +612,7 @@
static int __init hwrng_modinit(void)
{
- int ret = -ENOMEM;
+ int ret;
/* kmalloc makes this safe for virt_to_page() in virtio_rng.c */
rng_buffer = kmalloc(rng_buffer_size(), GFP_KERNEL);
@@ -617,11 +645,7 @@
unregister_miscdev();
}
-#ifdef CONFIG_ROCKCHIP_THUNDER_BOOT
-rootfs_initcall(hwrng_modinit);
-#else
module_init(hwrng_modinit);
-#endif
module_exit(hwrng_modexit);
MODULE_DESCRIPTION("H/W Random Number Generator (RNG) driver");
--
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