Merge tag 'random-6.2-rc1-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/crng/random

Pull random number generator updates from Jason Donenfeld:

 - Replace prandom_u32_max() and various open-coded variants of it,
   there is now a new family of functions that uses fast rejection
   sampling to choose properly uniformly random numbers within an
   interval:

       get_random_u32_below(ceil) - [0, ceil)
       get_random_u32_above(floor) - (floor, U32_MAX]
       get_random_u32_inclusive(floor, ceil) - [floor, ceil]

   Coccinelle was used to convert all current users of
   prandom_u32_max(), as well as many open-coded patterns, resulting in
   improvements throughout the tree.

   I'll have a "late" 6.1-rc1 pull for you that removes the now unused
   prandom_u32_max() function, just in case any other trees add a new
   use case of it that needs to converted. According to linux-next,
   there may be two trivial cases of prandom_u32_max() reintroductions
   that are fixable with a 's/.../.../'. So I'll have for you a final
   conversion patch doing that alongside the removal patch during the
   second week.

   This is a treewide change that touches many files throughout.

 - More consistent use of get_random_canary().

 - Updates to comments, documentation, tests, headers, and
   simplification in configuration.

 - The arch_get_random*_early() abstraction was only used by arm64 and
   wasn't entirely useful, so this has been replaced by code that works
   in all relevant contexts.

 - The kernel will use and manage random seeds in non-volatile EFI
   variables, refreshing a variable with a fresh seed when the RNG is
   initialized. The RNG GUID namespace is then hidden from efivarfs to
   prevent accidental leakage.

   These changes are split into random.c infrastructure code used in the
   EFI subsystem, in this pull request, and related support inside of
   EFISTUB, in Ard's EFI tree. These are co-dependent for full
   functionality, but the order of merging doesn't matter.

 - Part of the infrastructure added for the EFI support is also used for
   an improvement to the way vsprintf initializes its siphash key,
   replacing an sleep loop wart.

 - The hardware RNG framework now always calls its correct random.c
   input function, add_hwgenerator_randomness(), rather than sometimes
   going through helpers better suited for other cases.

 - The add_latent_entropy() function has long been called from the fork
   handler, but is a no-op when the latent entropy gcc plugin isn't
   used, which is fine for the purposes of latent entropy.

   But it was missing out on the cycle counter that was also being mixed
   in beside the latent entropy variable. So now, if the latent entropy
   gcc plugin isn't enabled, add_latent_entropy() will expand to a call
   to add_device_randomness(NULL, 0), which adds a cycle counter,
   without the absent latent entropy variable.

 - The RNG is now reseeded from a delayed worker, rather than on demand
   when used. Always running from a worker allows it to make use of the
   CPU RNG on platforms like S390x, whose instructions are too slow to
   do so from interrupts. It also has the effect of adding in new inputs
   more frequently with more regularity, amounting to a long term
   transcript of random values. Plus, it helps a bit with the upcoming
   vDSO implementation (which isn't yet ready for 6.2).

 - The jitter entropy algorithm now tries to execute on many different
   CPUs, round-robining, in hopes of hitting even more memory latencies
   and other unpredictable effects. It also will mix in a cycle counter
   when the entropy timer fires, in addition to being mixed in from the
   main loop, to account more explicitly for fluctuations in that timer
   firing. And the state it touches is now kept within the same cache
   line, so that it's assured that the different execution contexts will
   cause latencies.

* tag 'random-6.2-rc1-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/crng/random: (23 commits)
  random: include <linux/once.h> in the right header
  random: align entropy_timer_state to cache line
  random: mix in cycle counter when jitter timer fires
  random: spread out jitter callback to different CPUs
  random: remove extraneous period and add a missing one in comments
  efi: random: refresh non-volatile random seed when RNG is initialized
  vsprintf: initialize siphash key using notifier
  random: add back async readiness notifier
  random: reseed in delayed work rather than on-demand
  random: always mix cycle counter in add_latent_entropy()
  hw_random: use add_hwgenerator_randomness() for early entropy
  random: modernize documentation comment on get_random_bytes()
  random: adjust comment to account for removed function
  random: remove early archrandom abstraction
  random: use random.trust_{bootloader,cpu} command line option only
  stackprotector: actually use get_random_canary()
  stackprotector: move get_random_canary() into stackprotector.h
  treewide: use get_random_u32_inclusive() when possible
  treewide: use get_random_u32_{above,below}() instead of manual loop
  treewide: use get_random_u32_below() instead of deprecated function
  ...

35 files changed, 42 insertions, 147 deletions

diff --git a/arch/arm/include/asm/stackprotector.h b/arch/arm/include/asm/stackprotector.h
index 088d03161be5..0bd4979759f1 100644
--- a/arch/arm/include/asm/stackprotector.h
+++ b/arch/arm/include/asm/stackprotector.h
@@ -15,9 +15,6 @@
 #ifndef _ASM_STACKPROTECTOR_H
 #define _ASM_STACKPROTECTOR_H 1
 
-#include <linux/random.h>
-#include <linux/version.h>
-
 #include <asm/thread_info.h>
 
 extern unsigned long __stack_chk_guard;
@@ -30,11 +27,7 @@ extern unsigned long __stack_chk_guard;
  */
 static __always_inline void boot_init_stack_canary(void)
 {
-	unsigned long canary;
-
-	/* Try to get a semi random initial value. */
-	get_random_bytes(&canary, sizeof(canary));
-	canary ^= LINUX_VERSION_CODE;
+	unsigned long canary = get_random_canary();
 
 	current->stack_canary = canary;
 #ifndef CONFIG_STACKPROTECTOR_PER_TASK
diff --git a/arch/arm/kernel/process.c b/arch/arm/kernel/process.c
index a2b31d91a1b6..f811733a8fc5 100644
--- a/arch/arm/kernel/process.c
+++ b/arch/arm/kernel/process.c
@@ -371,7 +371,7 @@ static unsigned long sigpage_addr(const struct mm_struct *mm,
 
 	slots = ((last - first) >> PAGE_SHIFT) + 1;
 
-	offset = prandom_u32_max(slots);
+	offset = get_random_u32_below(slots);
 
 	addr = first + (offset << PAGE_SHIFT);
 
diff --git a/arch/arm64/include/asm/archrandom.h b/arch/arm64/include/asm/archrandom.h
index 109e2a4454be..2f5f3da34782 100644
--- a/arch/arm64/include/asm/archrandom.h
+++ b/arch/arm64/include/asm/archrandom.h
@@ -5,6 +5,7 @@
 #include <linux/arm-smccc.h>
 #include <linux/bug.h>
 #include <linux/kernel.h>
+#include <linux/irqflags.h>
 #include <asm/cpufeature.h>
 
 #define ARM_SMCCC_TRNG_MIN_VERSION	0x10000UL
@@ -58,6 +59,13 @@ static inline bool __arm64_rndrrs(unsigned long *v)
 	return ok;
 }
 
+static __always_inline bool __cpu_has_rng(void)
+{
+	if (unlikely(!system_capabilities_finalized() && !preemptible()))
+		return this_cpu_has_cap(ARM64_HAS_RNG);
+	return cpus_have_const_cap(ARM64_HAS_RNG);
+}
+
 static inline size_t __must_check arch_get_random_longs(unsigned long *v, size_t max_longs)
 {
 	/*
@@ -66,7 +74,7 @@ static inline size_t __must_check arch_get_random_longs(unsigned long *v, size_t
 	 * cpufeature code and with potential scheduling between CPUs
 	 * with and without the feature.
 	 */
-	if (max_longs && cpus_have_const_cap(ARM64_HAS_RNG) && __arm64_rndr(v))
+	if (max_longs && __cpu_has_rng() && __arm64_rndr(v))
 		return 1;
 	return 0;
 }
@@ -108,7 +116,7 @@ static inline size_t __must_check arch_get_random_seed_longs(unsigned long *v, s
 	 * reseeded after each invocation. This is not a 100% fit but good
 	 * enough to implement this API if no other entropy source exists.
 	 */
-	if (cpus_have_const_cap(ARM64_HAS_RNG) && __arm64_rndrrs(v))
+	if (__cpu_has_rng() && __arm64_rndrrs(v))
 		return 1;
 
 	return 0;
@@ -121,40 +129,4 @@ static inline bool __init __early_cpu_has_rndr(void)
 	return (ftr >> ID_AA64ISAR0_EL1_RNDR_SHIFT) & 0xf;
 }
 
-static inline size_t __init __must_check
-arch_get_random_seed_longs_early(unsigned long *v, size_t max_longs)
-{
-	WARN_ON(system_state != SYSTEM_BOOTING);
-
-	if (!max_longs)
-		return 0;
-
-	if (smccc_trng_available) {
-		struct arm_smccc_res res;
-
-		max_longs = min_t(size_t, 3, max_longs);
-		arm_smccc_1_1_invoke(ARM_SMCCC_TRNG_RND64, max_longs * 64, &res);
-		if ((int)res.a0 >= 0) {
-			switch (max_longs) {
-			case 3:
-				*v++ = res.a1;
-				fallthrough;
-			case 2:
-				*v++ = res.a2;
-				fallthrough;
-			case 1:
-				*v++ = res.a3;
-				break;
-			}
-			return max_longs;
-		}
-	}
-
-	if (__early_cpu_has_rndr() && __arm64_rndr(v))
-		return 1;
-
-	return 0;
-}
-#define arch_get_random_seed_longs_early arch_get_random_seed_longs_early
-
 #endif /* _ASM_ARCHRANDOM_H */
diff --git a/arch/arm64/include/asm/stackprotector.h b/arch/arm64/include/asm/stackprotector.h
index 33f1bb453150..ae3ad80f51fe 100644
--- a/arch/arm64/include/asm/stackprotector.h
+++ b/arch/arm64/include/asm/stackprotector.h
@@ -13,8 +13,6 @@
 #ifndef __ASM_STACKPROTECTOR_H
 #define __ASM_STACKPROTECTOR_H
 
-#include <linux/random.h>
-#include <linux/version.h>
 #include <asm/pointer_auth.h>
 
 extern unsigned long __stack_chk_guard;
@@ -28,12 +26,7 @@ extern unsigned long __stack_chk_guard;
 static __always_inline void boot_init_stack_canary(void)
 {
 #if defined(CONFIG_STACKPROTECTOR)
-	unsigned long canary;
-
-	/* Try to get a semi random initial value. */
-	get_random_bytes(&canary, sizeof(canary));
-	canary ^= LINUX_VERSION_CODE;
-	canary &= CANARY_MASK;
+	unsigned long canary = get_random_canary();
 
 	current->stack_canary = canary;
 	if (!IS_ENABLED(CONFIG_STACKPROTECTOR_PER_TASK))
diff --git a/arch/arm64/kernel/process.c b/arch/arm64/kernel/process.c
index 19cd05eea3f0..269ac1c25ae2 100644
--- a/arch/arm64/kernel/process.c
+++ b/arch/arm64/kernel/process.c
@@ -593,7 +593,7 @@ unsigned long __get_wchan(struct task_struct *p)
 unsigned long arch_align_stack(unsigned long sp)
 {
 	if (!(current->personality & ADDR_NO_RANDOMIZE) && randomize_va_space)
-		sp -= prandom_u32_max(PAGE_SIZE);
+		sp -= get_random_u32_below(PAGE_SIZE);
 	return sp & ~0xf;
 }
 
diff --git a/arch/csky/include/asm/stackprotector.h b/arch/csky/include/asm/stackprotector.h
index d7cd4e51edd9..d23747447166 100644
--- a/arch/csky/include/asm/stackprotector.h
+++ b/arch/csky/include/asm/stackprotector.h
@@ -2,9 +2,6 @@
 #ifndef _ASM_STACKPROTECTOR_H
 #define _ASM_STACKPROTECTOR_H 1
 
-#include <linux/random.h>
-#include <linux/version.h>
-
 extern unsigned long __stack_chk_guard;
 
 /*
@@ -15,12 +12,7 @@ extern unsigned long __stack_chk_guard;
  */
 static __always_inline void boot_init_stack_canary(void)
 {
-	unsigned long canary;
-
-	/* Try to get a semi random initial value. */
-	get_random_bytes(&canary, sizeof(canary));
-	canary ^= LINUX_VERSION_CODE;
-	canary &= CANARY_MASK;
+	unsigned long canary = get_random_canary();
 
 	current->stack_canary = canary;
 	__stack_chk_guard = current->stack_canary;
diff --git a/arch/loongarch/kernel/process.c b/arch/loongarch/kernel/process.c
index ddb8ba4eb399..d61c9f465b95 100644
--- a/arch/loongarch/kernel/process.c
+++ b/arch/loongarch/kernel/process.c
@@ -294,7 +294,7 @@ unsigned long stack_top(void)
 unsigned long arch_align_stack(unsigned long sp)
 {
 	if (!(current->personality & ADDR_NO_RANDOMIZE) && randomize_va_space)
-		sp -= prandom_u32_max(PAGE_SIZE);
+		sp -= get_random_u32_below(PAGE_SIZE);
 
 	return sp & STACK_ALIGN;
 }
diff --git a/arch/loongarch/kernel/vdso.c b/arch/loongarch/kernel/vdso.c
index 8c9826062652..eaebd2e0f725 100644
--- a/arch/loongarch/kernel/vdso.c
+++ b/arch/loongarch/kernel/vdso.c
@@ -78,7 +78,7 @@ static unsigned long vdso_base(void)
 	unsigned long base = STACK_TOP;
 
 	if (current->flags & PF_RANDOMIZE) {
-		base += prandom_u32_max(VDSO_RANDOMIZE_SIZE);
+		base += get_random_u32_below(VDSO_RANDOMIZE_SIZE);
 		base = PAGE_ALIGN(base);
 	}
 
diff --git a/arch/mips/include/asm/stackprotector.h b/arch/mips/include/asm/stackprotector.h
index 68d4be9e1254..518c192ad982 100644
--- a/arch/mips/include/asm/stackprotector.h
+++ b/arch/mips/include/asm/stackprotector.h
@@ -15,9 +15,6 @@
 #ifndef _ASM_STACKPROTECTOR_H
 #define _ASM_STACKPROTECTOR_H 1
 
-#include <linux/random.h>
-#include <linux/version.h>
-
 extern unsigned long __stack_chk_guard;
 
 /*
@@ -28,11 +25,7 @@ extern unsigned long __stack_chk_guard;
  */
 static __always_inline void boot_init_stack_canary(void)
 {
-	unsigned long canary;
-
-	/* Try to get a semi random initial value. */
-	get_random_bytes(&canary, sizeof(canary));
-	canary ^= LINUX_VERSION_CODE;
+	unsigned long canary = get_random_canary();
 
 	current->stack_canary = canary;
 	__stack_chk_guard = current->stack_canary;
diff --git a/arch/mips/kernel/process.c b/arch/mips/kernel/process.c
index bbe9ce471791..093dbbd6b843 100644
--- a/arch/mips/kernel/process.c
+++ b/arch/mips/kernel/process.c
@@ -711,7 +711,7 @@ unsigned long mips_stack_top(void)
 unsigned long arch_align_stack(unsigned long sp)
 {
 	if (!(current->personality & ADDR_NO_RANDOMIZE) && randomize_va_space)
-		sp -= prandom_u32_max(PAGE_SIZE);
+		sp -= get_random_u32_below(PAGE_SIZE);
 
 	return sp & ALMASK;
 }
diff --git a/arch/mips/kernel/vdso.c b/arch/mips/kernel/vdso.c
index 5fd9bf1d596c..f6d40e43f108 100644
--- a/arch/mips/kernel/vdso.c
+++ b/arch/mips/kernel/vdso.c
@@ -79,7 +79,7 @@ static unsigned long vdso_base(void)
 	}
 
 	if (current->flags & PF_RANDOMIZE) {
-		base += prandom_u32_max(VDSO_RANDOMIZE_SIZE);
+		base += get_random_u32_below(VDSO_RANDOMIZE_SIZE);
 		base = PAGE_ALIGN(base);
 	}
 
diff --git a/arch/parisc/kernel/vdso.c b/arch/parisc/kernel/vdso.c
index 47e5960a2f96..c5cbfce7a84c 100644
--- a/arch/parisc/kernel/vdso.c
+++ b/arch/parisc/kernel/vdso.c
@@ -75,7 +75,7 @@ int arch_setup_additional_pages(struct linux_binprm *bprm,
 
 	map_base = mm->mmap_base;
 	if (current->flags & PF_RANDOMIZE)
-		map_base -= prandom_u32_max(0x20) * PAGE_SIZE;
+		map_base -= get_random_u32_below(0x20) * PAGE_SIZE;
 
 	vdso_text_start = get_unmapped_area(NULL, map_base, vdso_text_len, 0, 0);
 
diff --git a/arch/powerpc/configs/microwatt_defconfig b/arch/powerpc/configs/microwatt_defconfig
index ea2dbd778aad..18d4fe4108cb 100644
--- a/arch/powerpc/configs/microwatt_defconfig
+++ b/arch/powerpc/configs/microwatt_defconfig
@@ -68,7 +68,6 @@ CONFIG_SERIAL_8250_CONSOLE=y
 CONFIG_SERIAL_OF_PLATFORM=y
 CONFIG_SERIAL_NONSTANDARD=y
 # CONFIG_NVRAM is not set
-CONFIG_RANDOM_TRUST_CPU=y
 CONFIG_SPI=y
 CONFIG_SPI_DEBUG=y
 CONFIG_SPI_BITBANG=y
diff --git a/arch/powerpc/crypto/crc-vpmsum_test.c b/arch/powerpc/crypto/crc-vpmsum_test.c
index 273c527868db..c61a874a3a5c 100644
--- a/arch/powerpc/crypto/crc-vpmsum_test.c
+++ b/arch/powerpc/crypto/crc-vpmsum_test.c
@@ -77,8 +77,8 @@ static int __init crc_test_init(void)
 
 		pr_info("crc-vpmsum_test begins, %lu iterations\n", iterations);
 		for (i=0; i<iterations; i++) {
-			size_t offset = prandom_u32_max(16);
-			size_t len = prandom_u32_max(MAX_CRC_LENGTH);
+			size_t offset = get_random_u32_below(16);
+			size_t len = get_random_u32_below(MAX_CRC_LENGTH);
 
 			if (len <= offset)
 				continue;
diff --git a/arch/powerpc/include/asm/stackprotector.h b/arch/powerpc/include/asm/stackprotector.h
index 1c8460e23583..283c34647856 100644
--- a/arch/powerpc/include/asm/stackprotector.h
+++ b/arch/powerpc/include/asm/stackprotector.h
@@ -7,8 +7,6 @@
 #ifndef _ASM_STACKPROTECTOR_H
 #define _ASM_STACKPROTECTOR_H
 
-#include <linux/random.h>
-#include <linux/version.h>
 #include <asm/reg.h>
 #include <asm/current.h>
 #include <asm/paca.h>
@@ -21,13 +19,7 @@
  */
 static __always_inline void boot_init_stack_canary(void)
 {
-	unsigned long canary;
-
-	/* Try to get a semi random initial value. */
-	canary = get_random_canary();
-	canary ^= mftb();
-	canary ^= LINUX_VERSION_CODE;
-	canary &= CANARY_MASK;
+	unsigned long canary = get_random_canary();
 
 	current->stack_canary = canary;
 #ifdef CONFIG_PPC64
diff --git a/arch/powerpc/kernel/process.c b/arch/powerpc/kernel/process.c
index 67da147fe34d..fcf604370c66 100644
--- a/arch/powerpc/kernel/process.c
+++ b/arch/powerpc/kernel/process.c
@@ -2303,6 +2303,6 @@ void notrace __ppc64_runlatch_off(void)
 unsigned long arch_align_stack(unsigned long sp)
 {
 	if (!(current->personality & ADDR_NO_RANDOMIZE) && randomize_va_space)
-		sp -= prandom_u32_max(PAGE_SIZE);
+		sp -= get_random_u32_below(PAGE_SIZE);
 	return sp & ~0xf;
 }
diff --git a/arch/riscv/include/asm/stackprotector.h b/arch/riscv/include/asm/stackprotector.h
index 09093af46565..43895b90fe3f 100644
--- a/arch/riscv/include/asm/stackprotector.h
+++ b/arch/riscv/include/asm/stackprotector.h
@@ -3,9 +3,6 @@
 #ifndef _ASM_RISCV_STACKPROTECTOR_H
 #define _ASM_RISCV_STACKPROTECTOR_H
 
-#include <linux/random.h>
-#include <linux/version.h>
-
 extern unsigned long __stack_chk_guard;
 
 /*
@@ -16,12 +13,7 @@ extern unsigned long __stack_chk_guard;
  */
 static __always_inline void boot_init_stack_canary(void)
 {
-	unsigned long canary;
-
-	/* Try to get a semi random initial value. */
-	get_random_bytes(&canary, sizeof(canary));
-	canary ^= LINUX_VERSION_CODE;
-	canary &= CANARY_MASK;
+	unsigned long canary = get_random_canary();
 
 	current->stack_canary = canary;
 	if (!IS_ENABLED(CONFIG_STACKPROTECTOR_PER_TASK))
diff --git a/arch/s390/configs/debug_defconfig b/arch/s390/configs/debug_defconfig
index 63807bd0b536..a7b4e1d82758 100644
--- a/arch/s390/configs/debug_defconfig
+++ b/arch/s390/configs/debug_defconfig
@@ -573,8 +573,6 @@ CONFIG_VIRTIO_CONSOLE=m
 CONFIG_HW_RANDOM_VIRTIO=m
 CONFIG_HANGCHECK_TIMER=m
 CONFIG_TN3270_FS=y
-# CONFIG_RANDOM_TRUST_CPU is not set
-# CONFIG_RANDOM_TRUST_BOOTLOADER is not set
 CONFIG_PPS=m
 # CONFIG_PTP_1588_CLOCK is not set
 # CONFIG_HWMON is not set
diff --git a/arch/s390/configs/defconfig b/arch/s390/configs/defconfig
index 4f9a98247442..2bc2d0fe5774 100644
--- a/arch/s390/configs/defconfig
+++ b/arch/s390/configs/defconfig
@@ -563,8 +563,6 @@ CONFIG_VIRTIO_CONSOLE=m
 CONFIG_HW_RANDOM_VIRTIO=m
 CONFIG_HANGCHECK_TIMER=m
 CONFIG_TN3270_FS=y
-# CONFIG_RANDOM_TRUST_CPU is not set
-# CONFIG_RANDOM_TRUST_BOOTLOADER is not set
 # CONFIG_PTP_1588_CLOCK is not set
 # CONFIG_HWMON is not set
 CONFIG_WATCHDOG=y
diff --git a/arch/s390/configs/zfcpdump_defconfig b/arch/s390/configs/zfcpdump_defconfig
index 5fe9948be644..ae14ab0b864d 100644
--- a/arch/s390/configs/zfcpdump_defconfig
+++ b/arch/s390/configs/zfcpdump_defconfig
@@ -58,7 +58,6 @@ CONFIG_ZFCP=y
 # CONFIG_VMCP is not set
 # CONFIG_MONWRITER is not set
 # CONFIG_S390_VMUR is not set
-# CONFIG_RANDOM_TRUST_BOOTLOADER is not set
 # CONFIG_HID is not set
 # CONFIG_VIRTIO_MENU is not set
 # CONFIG_VHOST_MENU is not set
diff --git a/arch/s390/kernel/process.c b/arch/s390/kernel/process.c
index 42af4b3aa02b..3f5d2db0b854 100644
--- a/arch/s390/kernel/process.c
+++ b/arch/s390/kernel/process.c
@@ -224,7 +224,7 @@ unsigned long __get_wchan(struct task_struct *p)
 unsigned long arch_align_stack(unsigned long sp)
 {
 	if (!(current->personality & ADDR_NO_RANDOMIZE) && randomize_va_space)
-		sp -= prandom_u32_max(PAGE_SIZE);
+		sp -= get_random_u32_below(PAGE_SIZE);
 	return sp & ~0xf;
 }
 
diff --git a/arch/s390/kernel/vdso.c b/arch/s390/kernel/vdso.c
index d6df7169c01f..ff7bf4432229 100644
--- a/arch/s390/kernel/vdso.c
+++ b/arch/s390/kernel/vdso.c
@@ -207,7 +207,7 @@ static unsigned long vdso_addr(unsigned long start, unsigned long len)
 	end -= len;
 
 	if (end > start) {
-		offset = prandom_u32_max(((end - start) >> PAGE_SHIFT) + 1);
+		offset = get_random_u32_below(((end - start) >> PAGE_SHIFT) + 1);
 		addr = start + (offset << PAGE_SHIFT);
 	} else {
 		addr = start;
diff --git a/arch/sh/include/asm/stackprotector.h b/arch/sh/include/asm/stackprotector.h
index 35616841d0a1..665dafac376f 100644
--- a/arch/sh/include/asm/stackprotector.h
+++ b/arch/sh/include/asm/stackprotector.h
@@ -2,9 +2,6 @@
 #ifndef __ASM_SH_STACKPROTECTOR_H
 #define __ASM_SH_STACKPROTECTOR_H
 
-#include <linux/random.h>
-#include <linux/version.h>
-
 extern unsigned long __stack_chk_guard;
 
 /*
@@ -15,12 +12,7 @@ extern unsigned long __stack_chk_guard;
  */
 static __always_inline void boot_init_stack_canary(void)
 {
-	unsigned long canary;
-
-	/* Try to get a semi random initial value. */
-	get_random_bytes(&canary, sizeof(canary));
-	canary ^= LINUX_VERSION_CODE;
-	canary &= CANARY_MASK;
+	unsigned long canary = get_random_canary();
 
 	current->stack_canary = canary;
 	__stack_chk_guard = current->stack_canary;
diff --git a/arch/sparc/vdso/vma.c b/arch/sparc/vdso/vma.c
index ae9a86cb6f3d..136c78f28f8b 100644
--- a/arch/sparc/vdso/vma.c
+++ b/arch/sparc/vdso/vma.c
@@ -354,7 +354,7 @@ static unsigned long vdso_addr(unsigned long start, unsigned int len)
 	unsigned int offset;
 
 	/* This loses some more bits than a modulo, but is cheaper */
-	offset = prandom_u32_max(PTRS_PER_PTE);
+	offset = get_random_u32_below(PTRS_PER_PTE);
 	return start + (offset << PAGE_SHIFT);
 }
 
diff --git a/arch/um/kernel/process.c b/arch/um/kernel/process.c
index 010bc422a09d..e38f41444721 100644
--- a/arch/um/kernel/process.c
+++ b/arch/um/kernel/process.c
@@ -356,7 +356,7 @@ int singlestepping(void * t)
 unsigned long arch_align_stack(unsigned long sp)
 {
 	if (!(current->personality & ADDR_NO_RANDOMIZE) && randomize_va_space)
-		sp -= prandom_u32_max(8192);
+		sp -= get_random_u32_below(8192);
 	return sp & ~0xf;
 }
 #endif
diff --git a/arch/x86/entry/vdso/vma.c b/arch/x86/entry/vdso/vma.c
index 3c6b488b2f11..b8f3f9b9e53c 100644
--- a/arch/x86/entry/vdso/vma.c
+++ b/arch/x86/entry/vdso/vma.c
@@ -303,7 +303,7 @@ static unsigned long vdso_addr(unsigned long start, unsigned len)
 	end -= len;
 
 	if (end > start) {
-		offset = prandom_u32_max(((end - start) >> PAGE_SHIFT) + 1);
+		offset = get_random_u32_below(((end - start) >> PAGE_SHIFT) + 1);
 		addr = start + (offset << PAGE_SHIFT);
 	} else {
 		addr = start;
diff --git a/arch/x86/include/asm/stackprotector.h b/arch/x86/include/asm/stackprotector.h
index 24a8d6c4fb18..00473a650f51 100644
--- a/arch/x86/include/asm/stackprotector.h
+++ b/arch/x86/include/asm/stackprotector.h
@@ -34,7 +34,6 @@
 #include <asm/percpu.h>
 #include <asm/desc.h>
 
-#include <linux/random.h>
 #include <linux/sched.h>
 
 /*
@@ -50,22 +49,11 @@
  */
 static __always_inline void boot_init_stack_canary(void)
 {
-	u64 canary;
-	u64 tsc;
+	unsigned long canary = get_random_canary();
 
 #ifdef CONFIG_X86_64
 	BUILD_BUG_ON(offsetof(struct fixed_percpu_data, stack_canary) != 40);
 #endif
-	/*
-	 * We both use the random pool and the current TSC as a source
-	 * of randomness. The TSC only matters for very early init,
-	 * there it already has some randomness on most systems. Later
-	 * on during the bootup the random pool has true entropy too.
-	 */
-	get_random_bytes(&canary, sizeof(canary));
-	tsc = rdtsc();
-	canary += tsc + (tsc << 32UL);
-	canary &= CANARY_MASK;
 
 	current->stack_canary = canary;
 #ifdef CONFIG_X86_64
diff --git a/arch/x86/kernel/cpu/common.c b/arch/x86/kernel/cpu/common.c
index 3e508f239098..3f66dd03c091 100644
--- a/arch/x86/kernel/cpu/common.c
+++ b/arch/x86/kernel/cpu/common.c
@@ -22,9 +22,9 @@
 #include <linux/io.h>
 #include <linux/syscore_ops.h>
 #include <linux/pgtable.h>
+#include <linux/stackprotector.h>
 
 #include <asm/cmdline.h>
-#include <asm/stackprotector.h>
 #include <asm/perf_event.h>
 #include <asm/mmu_context.h>
 #include <asm/doublefault.h>
diff --git a/arch/x86/kernel/module.c b/arch/x86/kernel/module.c
index c8a25aed604d..d85a6980e263 100644
--- a/arch/x86/kernel/module.c
+++ b/arch/x86/kernel/module.c
@@ -53,7 +53,7 @@ static unsigned long int get_module_load_offset(void)
 		 */
 		if (module_load_offset == 0)
 			module_load_offset =
-				(prandom_u32_max(1024) + 1) * PAGE_SIZE;
+				get_random_u32_inclusive(1, 1024) * PAGE_SIZE;
 		mutex_unlock(&module_kaslr_mutex);
 	}
 	return module_load_offset;
diff --git a/arch/x86/kernel/process.c b/arch/x86/kernel/process.c
index e436c9c1ef3b..40d156a31676 100644
--- a/arch/x86/kernel/process.c
+++ b/arch/x86/kernel/process.c
@@ -965,7 +965,7 @@ early_param("idle", idle_setup);
 unsigned long arch_align_stack(unsigned long sp)
 {
 	if (!(current->personality & ADDR_NO_RANDOMIZE) && randomize_va_space)
-		sp -= prandom_u32_max(8192);
+		sp -= get_random_u32_below(8192);
 	return sp & ~0xf;
 }
 
diff --git a/arch/x86/kernel/setup_percpu.c b/arch/x86/kernel/setup_percpu.c
index 49325caa7307..b26123c90b4f 100644
--- a/arch/x86/kernel/setup_percpu.c
+++ b/arch/x86/kernel/setup_percpu.c
@@ -11,6 +11,7 @@
 #include <linux/smp.h>
 #include <linux/topology.h>
 #include <linux/pfn.h>
+#include <linux/stackprotector.h>
 #include <asm/sections.h>
 #include <asm/processor.h>
 #include <asm/desc.h>
@@ -21,7 +22,6 @@
 #include <asm/proto.h>
 #include <asm/cpumask.h>
 #include <asm/cpu.h>
-#include <asm/stackprotector.h>
 
 DEFINE_PER_CPU_READ_MOSTLY(int, cpu_number);
 EXPORT_PER_CPU_SYMBOL(cpu_number);
diff --git a/arch/x86/kernel/smpboot.c b/arch/x86/kernel/smpboot.c
index 3f3ea0287f69..5a742b6ec46d 100644
--- a/arch/x86/kernel/smpboot.c
+++ b/arch/x86/kernel/smpboot.c
@@ -56,6 +56,7 @@
 #include <linux/numa.h>
 #include <linux/pgtable.h>
 #include <linux/overflow.h>
+#include <linux/stackprotector.h>
 
 #include <asm/acpi.h>
 #include <asm/desc.h>
diff --git a/arch/x86/mm/pat/cpa-test.c b/arch/x86/mm/pat/cpa-test.c
index 423b21e80929..3d2f7f0a6ed1 100644
--- a/arch/x86/mm/pat/cpa-test.c
+++ b/arch/x86/mm/pat/cpa-test.c
@@ -136,10 +136,10 @@ static int pageattr_test(void)
 	failed += print_split(&sa);
 
 	for (i = 0; i < NTEST; i++) {
-		unsigned long pfn = prandom_u32_max(max_pfn_mapped);
+		unsigned long pfn = get_random_u32_below(max_pfn_mapped);
 
 		addr[i] = (unsigned long)__va(pfn << PAGE_SHIFT);
-		len[i] = prandom_u32_max(NPAGES);
+		len[i] = get_random_u32_below(NPAGES);
 		len[i] = min_t(unsigned long, len[i], max_pfn_mapped - pfn - 1);
 
 		if (len[i] == 0)
diff --git a/arch/x86/xen/enlighten_pv.c b/arch/x86/xen/enlighten_pv.c
index 038da45f057a..1a2ba31635a5 100644
--- a/arch/x86/xen/enlighten_pv.c
+++ b/arch/x86/xen/enlighten_pv.c
@@ -33,6 +33,7 @@
 #include <linux/edd.h>
 #include <linux/reboot.h>
 #include <linux/virtio_anchor.h>
+#include <linux/stackprotector.h>
 
 #include <xen/xen.h>
 #include <xen/events.h>
@@ -65,7 +66,6 @@
 #include <asm/pgalloc.h>
 #include <asm/tlbflush.h>
 #include <asm/reboot.h>
-#include <asm/stackprotector.h>
 #include <asm/hypervisor.h>
 #include <asm/mach_traps.h>
 #include <asm/mwait.h>
diff --git a/arch/xtensa/include/asm/stackprotector.h b/arch/xtensa/include/asm/stackprotector.h
index e368f94fd2af..dd10279a2378 100644
--- a/arch/xtensa/include/asm/stackprotector.h
+++ b/arch/xtensa/include/asm/stackprotector.h
@@ -14,9 +14,6 @@
 #ifndef _ASM_STACKPROTECTOR_H
 #define _ASM_STACKPROTECTOR_H 1
 
-#include <linux/random.h>
-#include <linux/version.h>
-
 extern unsigned long __stack_chk_guard;
 
 /*
@@ -27,11 +24,7 @@ extern unsigned long __stack_chk_guard;
  */
 static __always_inline void boot_init_stack_canary(void)
 {
-	unsigned long canary;
-
-	/* Try to get a semi random initial value. */
-	get_random_bytes(&canary, sizeof(canary));
-	canary ^= LINUX_VERSION_CODE;
+	unsigned long canary = get_random_canary();
 
 	current->stack_canary = canary;
 	__stack_chk_guard = current->stack_canary;