Re: Linux 5.7.14

[Greg Kroah-Hartman <gregkh@linuxfoundation.org>]

diff --git a/Makefile b/Makefile
index b77b4332a41a..70942a6541d8 100644
--- a/Makefile
+++ b/Makefile
@@ -1,7 +1,7 @@
 # SPDX-License-Identifier: GPL-2.0
 VERSION = 5
 PATCHLEVEL = 7
-SUBLEVEL = 13
+SUBLEVEL = 14
 EXTRAVERSION =
 NAME = Kleptomaniac Octopus
 
diff --git a/arch/arm/include/asm/percpu.h b/arch/arm/include/asm/percpu.h
index f44f448537f2..1a3eedbac4a2 100644
--- a/arch/arm/include/asm/percpu.h
+++ b/arch/arm/include/asm/percpu.h
@@ -5,6 +5,8 @@
 #ifndef _ASM_ARM_PERCPU_H_
 #define _ASM_ARM_PERCPU_H_
 
+#include <asm/thread_info.h>
+
 /*
  * Same as asm-generic/percpu.h, except that we store the per cpu offset
  * in the TPIDRPRW. TPIDRPRW only exists on V6K and V7
diff --git a/arch/arm64/include/asm/archrandom.h b/arch/arm64/include/asm/archrandom.h
index fc1594a0710e..44209f6146aa 100644
--- a/arch/arm64/include/asm/archrandom.h
+++ b/arch/arm64/include/asm/archrandom.h
@@ -6,7 +6,6 @@
 
 #include <linux/bug.h>
 #include <linux/kernel.h>
-#include <linux/random.h>
 #include <asm/cpufeature.h>
 
 static inline bool __arm64_rndr(unsigned long *v)
diff --git a/arch/arm64/include/asm/pointer_auth.h b/arch/arm64/include/asm/pointer_auth.h
index c6b4f0603024..be7f853738e6 100644
--- a/arch/arm64/include/asm/pointer_auth.h
+++ b/arch/arm64/include/asm/pointer_auth.h
@@ -3,7 +3,6 @@
 #define __ASM_POINTER_AUTH_H
 
 #include <linux/bitops.h>
-#include <linux/random.h>
 
 #include <asm/cpufeature.h>
 #include <asm/memory.h>
@@ -34,6 +33,13 @@ struct ptrauth_keys_kernel {
 	struct ptrauth_key apia;
 };
 
+/*
+ * Only include random.h once ptrauth_keys_* structures are defined
+ * to avoid yet another circular include hell (random.h * ends up
+ * including asm/smp.h, which requires ptrauth_keys_kernel).
+ */
+#include <linux/random.h>
+
 static inline void ptrauth_keys_init_user(struct ptrauth_keys_user *keys)
 {
 	if (system_supports_address_auth()) {
diff --git a/arch/arm64/kernel/kaslr.c b/arch/arm64/kernel/kaslr.c
index 91a83104c6e8..e2101440c314 100644
--- a/arch/arm64/kernel/kaslr.c
+++ b/arch/arm64/kernel/kaslr.c
@@ -10,8 +10,8 @@
 #include <linux/mm_types.h>
 #include <linux/sched.h>
 #include <linux/types.h>
+#include <linux/random.h>
 
-#include <asm/archrandom.h>
 #include <asm/cacheflush.h>
 #include <asm/fixmap.h>
 #include <asm/kernel-pgtable.h>
diff --git a/drivers/char/random.c b/drivers/char/random.c
index 0d10e31fd342..344a57ebb35e 100644
--- a/drivers/char/random.c
+++ b/drivers/char/random.c
@@ -1277,6 +1277,7 @@ void add_interrupt_randomness(int irq, int irq_flags)
 
 	fast_mix(fast_pool);
 	add_interrupt_bench(cycles);
+	this_cpu_add(net_rand_state.s1, fast_pool->pool[cycles & 3]);
 
 	if (unlikely(crng_init == 0)) {
 		if ((fast_pool->count >= 64) &&
diff --git a/include/linux/prandom.h b/include/linux/prandom.h
new file mode 100644
index 000000000000..aa16e6468f91
--- /dev/null
+++ b/include/linux/prandom.h
@@ -0,0 +1,78 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * include/linux/prandom.h
+ *
+ * Include file for the fast pseudo-random 32-bit
+ * generation.
+ */
+#ifndef _LINUX_PRANDOM_H
+#define _LINUX_PRANDOM_H
+
+#include <linux/types.h>
+#include <linux/percpu.h>
+
+u32 prandom_u32(void);
+void prandom_bytes(void *buf, size_t nbytes);
+void prandom_seed(u32 seed);
+void prandom_reseed_late(void);
+
+struct rnd_state {
+	__u32 s1, s2, s3, s4;
+};
+
+DECLARE_PER_CPU(struct rnd_state, net_rand_state);
+
+u32 prandom_u32_state(struct rnd_state *state);
+void prandom_bytes_state(struct rnd_state *state, void *buf, size_t nbytes);
+void prandom_seed_full_state(struct rnd_state __percpu *pcpu_state);
+
+#define prandom_init_once(pcpu_state)			\
+	DO_ONCE(prandom_seed_full_state, (pcpu_state))
+
+/**
+ * prandom_u32_max - returns a pseudo-random number in interval [0, ep_ro)
+ * @ep_ro: right open interval endpoint
+ *
+ * Returns a pseudo-random number that is in interval [0, ep_ro). Note
+ * that the result depends on PRNG being well distributed in [0, ~0U]
+ * u32 space. Here we use maximally equidistributed combined Tausworthe
+ * generator, that is, prandom_u32(). This is useful when requesting a
+ * random index of an array containing ep_ro elements, for example.
+ *
+ * Returns: pseudo-random number in interval [0, ep_ro)
+ */
+static inline u32 prandom_u32_max(u32 ep_ro)
+{
+	return (u32)(((u64) prandom_u32() * ep_ro) >> 32);
+}
+
+/*
+ * Handle minimum values for seeds
+ */
+static inline u32 __seed(u32 x, u32 m)
+{
+	return (x < m) ? x + m : x;
+}
+
+/**
+ * prandom_seed_state - set seed for prandom_u32_state().
+ * @state: pointer to state structure to receive the seed.
+ * @seed: arbitrary 64-bit value to use as a seed.
+ */
+static inline void prandom_seed_state(struct rnd_state *state, u64 seed)
+{
+	u32 i = (seed >> 32) ^ (seed << 10) ^ seed;
+
+	state->s1 = __seed(i,   2U);
+	state->s2 = __seed(i,   8U);
+	state->s3 = __seed(i,  16U);
+	state->s4 = __seed(i, 128U);
+}
+
+/* Pseudo random number generator from numerical recipes. */
+static inline u32 next_pseudo_random32(u32 seed)
+{
+	return seed * 1664525 + 1013904223;
+}
+
+#endif
diff --git a/include/linux/random.h b/include/linux/random.h
index 45e1f8fa742b..f45b8be3e3c4 100644
--- a/include/linux/random.h
+++ b/include/linux/random.h
@@ -110,61 +110,12 @@ declare_get_random_var_wait(long)
 
 unsigned long randomize_page(unsigned long start, unsigned long range);
 
-u32 prandom_u32(void);
-void prandom_bytes(void *buf, size_t nbytes);
-void prandom_seed(u32 seed);
-void prandom_reseed_late(void);
-
-struct rnd_state {
-	__u32 s1, s2, s3, s4;
-};
-
-u32 prandom_u32_state(struct rnd_state *state);
-void prandom_bytes_state(struct rnd_state *state, void *buf, size_t nbytes);
-void prandom_seed_full_state(struct rnd_state __percpu *pcpu_state);
-
-#define prandom_init_once(pcpu_state)			\
-	DO_ONCE(prandom_seed_full_state, (pcpu_state))
-
-/**
- * prandom_u32_max - returns a pseudo-random number in interval [0, ep_ro)
- * @ep_ro: right open interval endpoint
- *
- * Returns a pseudo-random number that is in interval [0, ep_ro). Note
- * that the result depends on PRNG being well distributed in [0, ~0U]
- * u32 space. Here we use maximally equidistributed combined Tausworthe
- * generator, that is, prandom_u32(). This is useful when requesting a
- * random index of an array containing ep_ro elements, for example.
- *
- * Returns: pseudo-random number in interval [0, ep_ro)
- */
-static inline u32 prandom_u32_max(u32 ep_ro)
-{
-	return (u32)(((u64) prandom_u32() * ep_ro) >> 32);
-}
-
 /*
- * Handle minimum values for seeds
+ * This is designed to be standalone for just prandom
+ * users, but for now we include it from <linux/random.h>
+ * for legacy reasons.
  */
-static inline u32 __seed(u32 x, u32 m)
-{
-	return (x < m) ? x + m : x;
-}
-
-/**
- * prandom_seed_state - set seed for prandom_u32_state().
- * @state: pointer to state structure to receive the seed.
- * @seed: arbitrary 64-bit value to use as a seed.
- */
-static inline void prandom_seed_state(struct rnd_state *state, u64 seed)
-{
-	u32 i = (seed >> 32) ^ (seed << 10) ^ seed;
-
-	state->s1 = __seed(i,   2U);
-	state->s2 = __seed(i,   8U);
-	state->s3 = __seed(i,  16U);
-	state->s4 = __seed(i, 128U);
-}
+#include <linux/prandom.h>
 
 #ifdef CONFIG_ARCH_RANDOM
 # include <asm/archrandom.h>
@@ -207,10 +158,4 @@ static inline bool __init arch_get_random_long_early(unsigned long *v)
 }
 #endif
 
-/* Pseudo random number generator from numerical recipes. */
-static inline u32 next_pseudo_random32(u32 seed)
-{
-	return seed * 1664525 + 1013904223;
-}
-
 #endif /* _LINUX_RANDOM_H */
diff --git a/kernel/time/timer.c b/kernel/time/timer.c
index 03c9fc395ab1..721d5af8cfc7 100644
--- a/kernel/time/timer.c
+++ b/kernel/time/timer.c
@@ -43,6 +43,7 @@
 #include <linux/sched/debug.h>
 #include <linux/slab.h>
 #include <linux/compat.h>
+#include <linux/random.h>
 
 #include <linux/uaccess.h>
 #include <asm/unistd.h>
@@ -1743,6 +1744,13 @@ void update_process_times(int user_tick)
 	scheduler_tick();
 	if (IS_ENABLED(CONFIG_POSIX_TIMERS))
 		run_posix_cpu_timers();
+
+	/* The current CPU might make use of net randoms without receiving IRQs
+	 * to renew them often enough. Let's update the net_rand_state from a
+	 * non-constant value that's not affine to the number of calls to make
+	 * sure it's updated when there's some activity (we don't care in idle).
+	 */
+	this_cpu_add(net_rand_state.s1, rol32(jiffies, 24) + user_tick);
 }
 
 /**
diff --git a/lib/random32.c b/lib/random32.c
index 763b920a6206..3d749abb9e80 100644
--- a/lib/random32.c
+++ b/lib/random32.c
@@ -48,7 +48,7 @@ static inline void prandom_state_selftest(void)
 }
 #endif
 
-static DEFINE_PER_CPU(struct rnd_state, net_rand_state) __latent_entropy;
+DEFINE_PER_CPU(struct rnd_state, net_rand_state);
 
 /**
  *	prandom_u32_state - seeded pseudo-random number generator.