Revert the random patch

Signed-off-by: Justin M. Forbes <jforbes@fedoraproject.org>

1 files changed, 237 insertions, 0 deletions

diff --git a/patch-5.19-redhat.patch b/patch-5.19-redhat.patch
index c51151298..4318db327 100644
--- a/patch-5.19-redhat.patch
+++ b/patch-5.19-redhat.patch
@@ -3333,3 +3333,240 @@ index 188b8f782220..dab400de2335 100644
  #ifdef CONFIG_PERF_EVENTS
  int security_perf_event_open(struct perf_event_attr *attr, int type)
  {
+From 900f11e054896bae7b0146055698656e3d1e20a6 Mon Sep 17 00:00:00 2001
+From: "Justin M. Forbes" <jforbes@fedoraproject.org>
+Date: Wed, 25 May 2022 15:55:40 -0500
+Subject: [PATCH] Revert random: Add hook to override device reads and
+ getrandom(2)
+
+The random system upstream is in a period of major rewrite.  In the 5.18
+merge window, it took a considerable amount of time to message this into
+the random.c rewrites. In the 5.19 merge window, rng->extrng_read(buf,
+count); does not even compile, with buf and count undefined.   As I do
+not see the subsequent patch that allows the override with a FIPS rng, I
+am just reverting the whole thing, and it can be added back when Herbert
+has time or motivation to do so.
+
+Signed-off-by: Justin M. Forbes <jforbes@fedoraproject.org>
+---
+ drivers/char/random.c  | 113 -----------------------------------------
+ include/linux/random.h |   8 ---
+ 2 files changed, 121 deletions(-)
+
+diff --git a/drivers/char/random.c b/drivers/char/random.c
+index 5d7a1fdf1edd..b691b9d59503 100644
+--- a/drivers/char/random.c
++++ b/drivers/char/random.c
+@@ -53,7 +53,6 @@
+ #include <linux/uaccess.h>
+ #include <linux/suspend.h>
+ #include <linux/siphash.h>
+-#include <linux/rcupdate.h>
+ #include <crypto/chacha.h>
+ #include <crypto/blake2s.h>
+ #include <asm/processor.h>
+@@ -282,11 +281,6 @@ static bool crng_has_old_seed(void)
+ 	return time_is_before_jiffies(READ_ONCE(base_crng.birth) + interval);
+ }
+
+-/*
+- * Hook for external RNG.
+- */
+-static const struct random_extrng __rcu *extrng;
+-
+ /*
+  * This function returns a ChaCha state that you may use for generating
+  * random data. It also returns up to 32 bytes on its own of random data
+@@ -675,9 +669,6 @@ static void __cold _credit_init_bits(size_t bits)
+ }
+
+
+-static const struct file_operations extrng_random_fops;
+-static const struct file_operations extrng_urandom_fops;
+-
+ /**********************************************************************
+  *
+  * Entropy collection routines.
+@@ -882,19 +873,6 @@ void __cold add_bootloader_randomness(const void *buf, size_t len)
+ }
+ EXPORT_SYMBOL_GPL(add_bootloader_randomness);
+
+-void random_register_extrng(const struct random_extrng *rng)
+-{
+-	rcu_assign_pointer(extrng, rng);
+-}
+-EXPORT_SYMBOL_GPL(random_register_extrng);
+-
+-void random_unregister_extrng(void)
+-{
+-	RCU_INIT_POINTER(extrng, NULL);
+-	synchronize_rcu();
+-}
+-EXPORT_SYMBOL_GPL(random_unregister_extrng);
+-
+ #if IS_ENABLED(CONFIG_VMGENID)
+ static BLOCKING_NOTIFIER_HEAD(vmfork_chain);
+
+@@ -1265,7 +1243,6 @@ SYSCALL_DEFINE3(getrandom, char __user *, ubuf, size_t, len, unsigned int, flags
+ 	struct iov_iter iter;
+ 	struct iovec iov;
+ 	int ret;
+-	const struct random_extrng *rng;
+
+ 	if (flags & ~(GRND_NONBLOCK | GRND_RANDOM | GRND_INSECURE))
+ 		return -EINVAL;
+@@ -1277,18 +1254,6 @@ SYSCALL_DEFINE3(getrandom, char __user *, ubuf, size_t, len, unsigned int, flags
+ 	if ((flags & (GRND_INSECURE | GRND_RANDOM)) == (GRND_INSECURE | GRND_RANDOM))
+ 		return -EINVAL;
+
+-	rcu_read_lock();
+-	rng = rcu_dereference(extrng);
+-	if (rng && !try_module_get(rng->owner))
+-		rng = NULL;
+-	rcu_read_unlock();
+-
+-	if (rng) {
+-		ret = rng->extrng_read(buf, count);
+-		module_put(rng->owner);
+-		return ret;
+-	}
+-
+ 	if (!crng_ready() && !(flags & GRND_INSECURE)) {
+ 		if (flags & GRND_NONBLOCK)
+ 			return -EAGAIN;
+@@ -1309,12 +1274,6 @@ static __poll_t random_poll(struct file *file, poll_table *wait)
+ 	return crng_ready() ? EPOLLIN | EPOLLRDNORM : EPOLLOUT | EPOLLWRNORM;
+ }
+
+-static __poll_t extrng_poll(struct file *file, poll_table * wait)
+-{
+-	/* extrng pool is always full, always read, no writes */
+-	return EPOLLIN | EPOLLRDNORM;
+-}
+-
+ static ssize_t write_pool_user(struct iov_iter *iter)
+ {
+ 	u8 block[BLAKE2S_BLOCK_SIZE];
+@@ -1451,58 +1410,7 @@ static int random_fasync(int fd, struct file *filp, int on)
+ 	return fasync_helper(fd, filp, on, &fasync);
+ }
+
+-static int random_open(struct inode *inode, struct file *filp)
+-{
+-	const struct random_extrng *rng;
+-
+-	rcu_read_lock();
+-	rng = rcu_dereference(extrng);
+-	if (rng && !try_module_get(rng->owner))
+-		rng = NULL;
+-	rcu_read_unlock();
+-
+-	if (!rng)
+-		return 0;
+-
+-	filp->f_op = &extrng_random_fops;
+-	filp->private_data = rng->owner;
+-
+-	return 0;
+-}
+-
+-static int urandom_open(struct inode *inode, struct file *filp)
+-{
+-	const struct random_extrng *rng;
+-
+-	rcu_read_lock();
+-	rng = rcu_dereference(extrng);
+-	if (rng && !try_module_get(rng->owner))
+-		rng = NULL;
+-	rcu_read_unlock();
+-
+-	if (!rng)
+-		return 0;
+-
+-	filp->f_op = &extrng_urandom_fops;
+-	filp->private_data = rng->owner;
+-
+-	return 0;
+-}
+-
+-static int extrng_release(struct inode *inode, struct file *filp)
+-{
+-	module_put(filp->private_data);
+-	return 0;
+-}
+-
+-static ssize_t
+-extrng_read(struct file *file, char __user *buf, size_t nbytes, loff_t *ppos)
+-{
+-	return rcu_dereference_raw(extrng)->extrng_read(buf, nbytes);
+-}
+-
+ const struct file_operations random_fops = {
+-	.open  = random_open,
+ 	.read_iter = random_read_iter,
+ 	.write_iter = random_write_iter,
+ 	.poll = random_poll,
+@@ -1515,7 +1423,6 @@ const struct file_operations random_fops = {
+ };
+
+ const struct file_operations urandom_fops = {
+-	.open  = urandom_open,
+ 	.read_iter = urandom_read_iter,
+ 	.write_iter = random_write_iter,
+ 	.unlocked_ioctl = random_ioctl,
+@@ -1526,26 +1433,6 @@ const struct file_operations urandom_fops = {
+ 	.splice_write = iter_file_splice_write,
+ };
+
+-static const struct file_operations extrng_random_fops = {
+-	.open  = random_open,
+-	.read  = extrng_read,
+-	.write = random_write,
+-	.poll  = extrng_poll,
+-	.unlocked_ioctl = random_ioctl,
+-	.fasync = random_fasync,
+-	.llseek = noop_llseek,
+-	.release = extrng_release,
+-};
+-
+-static const struct file_operations extrng_urandom_fops = {
+-	.open  = urandom_open,
+-	.read  = extrng_read,
+-	.write = random_write,
+-	.unlocked_ioctl = random_ioctl,
+-	.fasync = random_fasync,
+-	.llseek = noop_llseek,
+-	.release = extrng_release,
+-};
+
+ /********************************************************************
+  *
+diff --git a/include/linux/random.h b/include/linux/random.h
+index c36b7c412de2..fae0c84027fd 100644
+--- a/include/linux/random.h
++++ b/include/linux/random.h
+@@ -10,11 +10,6 @@
+
+ #include <uapi/linux/random.h>
+
+-struct random_extrng {
+-	ssize_t (*extrng_read)(void __user *buf, size_t buflen);
+-	struct module *owner;
+-};
+-
+ struct notifier_block;
+
+ void add_device_randomness(const void *buf, size_t len);
+@@ -146,9 +141,6 @@ int random_prepare_cpu(unsigned int cpu);
+ int random_online_cpu(unsigned int cpu);
+ #endif
+
+-void random_register_extrng(const struct random_extrng *rng);
+-void random_unregister_extrng(void);
+-
+ #ifndef MODULE
+ extern const struct file_operations random_fops, urandom_fops;
+ #endif
+-- 
+2.36.1
+