--- /dev/null
+From 585524081ecdcde1c719e63916c514866d898217 Mon Sep 17 00:00:00 2001
+From: Linus Torvalds <torvalds@linux-foundation.org>
+Date: Wed, 5 Aug 2020 12:39:48 -0700
+Subject: random: random.h should include archrandom.h, not the other way around
+MIME-Version: 1.0
+Content-Type: text/plain; charset=UTF-8
+Content-Transfer-Encoding: 8bit
+
+From: Linus Torvalds <torvalds@linux-foundation.org>
+
+commit 585524081ecdcde1c719e63916c514866d898217 upstream.
+
+This is hopefully the final piece of the crazy puzzle with random.h
+dependencies.
+
+And by "hopefully" I obviously mean "Linus is a hopeless optimist".
+
+Reported-and-tested-by: Daniel Díaz <daniel.diaz@linaro.org>
+Acked-by: Guenter Roeck <linux@roeck-us.net>
+Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
+Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+
+---
+ arch/arm64/include/asm/archrandom.h | 1 -
+ arch/arm64/kernel/kaslr.c | 2 +-
+ 2 files changed, 1 insertion(+), 2 deletions(-)
+
+--- 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)
+--- a/arch/arm64/kernel/kaslr.c
++++ b/arch/arm64/kernel/kaslr.c
+@@ -11,8 +11,8 @@
+ #include <linux/sched.h>
+ #include <linux/types.h>
+ #include <linux/pgtable.h>
++#include <linux/random.h>
+
+-#include <asm/archrandom.h>
+ #include <asm/cacheflush.h>
+ #include <asm/fixmap.h>
+ #include <asm/kernel-pgtable.h>
--- /dev/null
+From c0842fbc1b18c7a044e6ff3e8fa78bfa822c7d1a Mon Sep 17 00:00:00 2001
+From: Linus Torvalds <torvalds@linux-foundation.org>
+Date: Fri, 31 Jul 2020 07:51:14 +0200
+Subject: random32: move the pseudo-random 32-bit definitions to prandom.h
+
+From: Linus Torvalds <torvalds@linux-foundation.org>
+
+commit c0842fbc1b18c7a044e6ff3e8fa78bfa822c7d1a upstream.
+
+The addition of percpu.h to the list of includes in random.h revealed
+some circular dependencies on arm64 and possibly other platforms. This
+include was added solely for the pseudo-random definitions, which have
+nothing to do with the rest of the definitions in this file but are
+still there for legacy reasons.
+
+This patch moves the pseudo-random parts to linux/prandom.h and the
+percpu.h include with it, which is now guarded by _LINUX_PRANDOM_H and
+protected against recursive inclusion.
+
+A further cleanup step would be to remove this from <linux/random.h>
+entirely, and make people who use the prandom infrastructure include
+just the new header file. That's a bit of a churn patch, but grepping
+for "prandom_" and "next_pseudo_random32" "struct rnd_state" should
+catch most users.
+
+But it turns out that that nice cleanup step is fairly painful, because
+a _lot_ of code currently seems to depend on the implicit include of
+<linux/random.h>, which can currently come in a lot of ways, including
+such fairly core headfers as <linux/net.h>.
+
+So the "nice cleanup" part may or may never happen.
+
+Fixes: 1c9df907da83 ("random: fix circular include dependency on arm64 after addition of percpu.h")
+Tested-by: Guenter Roeck <linux@roeck-us.net>
+Acked-by: Willy Tarreau <w@1wt.eu>
+Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
+Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+
+---
+ include/linux/prandom.h | 78 ++++++++++++++++++++++++++++++++++++++++++++++++
+ include/linux/random.h | 66 ++--------------------------------------
+ 2 files changed, 82 insertions(+), 62 deletions(-)
+
+--- /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
+--- a/include/linux/random.h
++++ b/include/linux/random.h
+@@ -11,7 +11,6 @@
+ #include <linux/kernel.h>
+ #include <linux/list.h>
+ #include <linux/once.h>
+-#include <asm/percpu.h>
+
+ #include <uapi/linux/random.h>
+
+@@ -111,63 +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;
+-};
+-
+-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.
++ * 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 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>
+@@ -210,10 +158,4 @@ static inline bool __init arch_get_rando
+ }
+ #endif
+
+-/* Pseudo random number generator from numerical recipes. */
+-static inline u32 next_pseudo_random32(u32 seed)
+-{
+- return seed * 1664525 + 1013904223;
+-}
+-
+ #endif /* _LINUX_RANDOM_H */
projects / thirdparty / kernel / stable-queue.git / commitdiff
