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-rw-r--r--drivers/char/Kconfig50
-rw-r--r--drivers/char/random.c39
-rw-r--r--include/linux/crc-itu-t.h2
-rw-r--r--include/linux/random.h3
-rw-r--r--lib/crc-itu-t.c2
-rw-r--r--lib/vsprintf.c3
-rw-r--r--tools/testing/selftests/wireguard/qemu/Makefile28
-rw-r--r--tools/testing/selftests/wireguard/qemu/init.c3
-rw-r--r--tools/testing/selftests/wireguard/qemu/kernel.config3
9 files changed, 71 insertions, 62 deletions
diff --git a/drivers/char/Kconfig b/drivers/char/Kconfig
index 69fd31ffb847..0b6c03643ddc 100644
--- a/drivers/char/Kconfig
+++ b/drivers/char/Kconfig
@@ -429,28 +429,40 @@ config ADI
driver include crash and makedumpfile.
config RANDOM_TRUST_CPU
- bool "Trust the CPU manufacturer to initialize Linux's CRNG"
+ bool "Initialize RNG using CPU RNG instructions"
+ default y
depends on ARCH_RANDOM
- default n
help
- Assume that CPU manufacturer (e.g., Intel or AMD for RDSEED or
- RDRAND, IBM for the S390 and Power PC architectures) is trustworthy
- for the purposes of initializing Linux's CRNG. Since this is not
- something that can be independently audited, this amounts to trusting
- that CPU manufacturer (perhaps with the insistence or mandate
- of a Nation State's intelligence or law enforcement agencies)
- has not installed a hidden back door to compromise the CPU's
- random number generation facilities. This can also be configured
- at boot with "random.trust_cpu=on/off".
+ Initialize the RNG using random numbers supplied by the CPU's
+ RNG instructions (e.g. RDRAND), if supported and available. These
+ random numbers are never used directly, but are rather hashed into
+ the main input pool, and this happens regardless of whether or not
+ this option is enabled. Instead, this option controls whether the
+ they are credited and hence can initialize the RNG. Additionally,
+ other sources of randomness are always used, regardless of this
+ setting. Enabling this implies trusting that the CPU can supply high
+ quality and non-backdoored random numbers.
+
+ Say Y here unless you have reason to mistrust your CPU or believe
+ its RNG facilities may be faulty. This may also be configured at
+ boot time with "random.trust_cpu=on/off".
config RANDOM_TRUST_BOOTLOADER
- bool "Trust the bootloader to initialize Linux's CRNG"
- help
- Some bootloaders can provide entropy to increase the kernel's initial
- device randomness. Say Y here to assume the entropy provided by the
- booloader is trustworthy so it will be added to the kernel's entropy
- pool. Otherwise, say N here so it will be regarded as device input that
- only mixes the entropy pool. This can also be configured at boot with
- "random.trust_bootloader=on/off".
+ bool "Initialize RNG using bootloader-supplied seed"
+ default y
+ help
+ Initialize the RNG using a seed supplied by the bootloader or boot
+ environment (e.g. EFI or a bootloader-generated device tree). This
+ seed is not used directly, but is rather hashed into the main input
+ pool, and this happens regardless of whether or not this option is
+ enabled. Instead, this option controls whether the seed is credited
+ and hence can initialize the RNG. Additionally, other sources of
+ randomness are always used, regardless of this setting. Enabling
+ this implies trusting that the bootloader can supply high quality and
+ non-backdoored seeds.
+
+ Say Y here unless you have reason to mistrust your bootloader or
+ believe its RNG facilities may be faulty. This may also be configured
+ at boot time with "random.trust_bootloader=on/off".
endmenu
diff --git a/drivers/char/random.c b/drivers/char/random.c
index b691b9d59503..655e327d425e 100644
--- a/drivers/char/random.c
+++ b/drivers/char/random.c
@@ -650,7 +650,8 @@ static void __cold _credit_init_bits(size_t bits)
if (orig < POOL_READY_BITS && new >= POOL_READY_BITS) {
crng_reseed(); /* Sets crng_init to CRNG_READY under base_crng.lock. */
- execute_in_process_context(crng_set_ready, &set_ready);
+ if (static_key_initialized)
+ execute_in_process_context(crng_set_ready, &set_ready);
wake_up_interruptible(&crng_init_wait);
kill_fasync(&fasync, SIGIO, POLL_IN);
pr_notice("crng init done\n");
@@ -724,9 +725,8 @@ static void __cold _credit_init_bits(size_t bits)
*
**********************************************************************/
-static bool used_arch_random;
-static bool trust_cpu __ro_after_init = IS_ENABLED(CONFIG_RANDOM_TRUST_CPU);
-static bool trust_bootloader __ro_after_init = IS_ENABLED(CONFIG_RANDOM_TRUST_BOOTLOADER);
+static bool trust_cpu __initdata = IS_ENABLED(CONFIG_RANDOM_TRUST_CPU);
+static bool trust_bootloader __initdata = IS_ENABLED(CONFIG_RANDOM_TRUST_BOOTLOADER);
static int __init parse_trust_cpu(char *arg)
{
return kstrtobool(arg, &trust_cpu);
@@ -776,7 +776,7 @@ static struct notifier_block pm_notifier = { .notifier_call = random_pm_notifica
int __init random_init(const char *command_line)
{
ktime_t now = ktime_get_real();
- unsigned int i, arch_bytes;
+ unsigned int i, arch_bits;
unsigned long entropy;
#if defined(LATENT_ENTROPY_PLUGIN)
@@ -784,12 +784,12 @@ int __init random_init(const char *command_line)
_mix_pool_bytes(compiletime_seed, sizeof(compiletime_seed));
#endif
- for (i = 0, arch_bytes = BLAKE2S_BLOCK_SIZE;
+ for (i = 0, arch_bits = BLAKE2S_BLOCK_SIZE * 8;
i < BLAKE2S_BLOCK_SIZE; i += sizeof(entropy)) {
if (!arch_get_random_seed_long_early(&entropy) &&
!arch_get_random_long_early(&entropy)) {
entropy = random_get_entropy();
- arch_bytes -= sizeof(entropy);
+ arch_bits -= sizeof(entropy) * 8;
}
_mix_pool_bytes(&entropy, sizeof(entropy));
}
@@ -798,11 +798,18 @@ int __init random_init(const char *command_line)
_mix_pool_bytes(command_line, strlen(command_line));
add_latent_entropy();
+ /*
+ * If we were initialized by the bootloader before jump labels are
+ * initialized, then we should enable the static branch here, where
+ * it's guaranteed that jump labels have been initialized.
+ */
+ if (!static_branch_likely(&crng_is_ready) && crng_init >= CRNG_READY)
+ crng_set_ready(NULL);
+
if (crng_ready())
crng_reseed();
else if (trust_cpu)
- credit_init_bits(arch_bytes * 8);
- used_arch_random = arch_bytes * 8 >= POOL_READY_BITS;
+ _credit_init_bits(arch_bits);
WARN_ON(register_pm_notifier(&pm_notifier));
@@ -812,17 +819,6 @@ int __init random_init(const char *command_line)
}
/*
- * Returns whether arch randomness has been mixed into the initial
- * state of the RNG, regardless of whether or not that randomness
- * was credited. Knowing this is only good for a very limited set
- * of uses, such as early init printk pointer obfuscation.
- */
-bool rng_has_arch_random(void)
-{
- return used_arch_random;
-}
-
-/*
* Add device- or boot-specific data to the input pool to help
* initialize it.
*
@@ -865,13 +861,12 @@ EXPORT_SYMBOL_GPL(add_hwgenerator_randomness);
* Handle random seed passed by bootloader, and credit it if
* CONFIG_RANDOM_TRUST_BOOTLOADER is set.
*/
-void __cold add_bootloader_randomness(const void *buf, size_t len)
+void __init add_bootloader_randomness(const void *buf, size_t len)
{
mix_pool_bytes(buf, len);
if (trust_bootloader)
credit_init_bits(len * 8);
}
-EXPORT_SYMBOL_GPL(add_bootloader_randomness);
#if IS_ENABLED(CONFIG_VMGENID)
static BLOCKING_NOTIFIER_HEAD(vmfork_chain);
diff --git a/include/linux/crc-itu-t.h b/include/linux/crc-itu-t.h
index a4367051e192..2f991a427ade 100644
--- a/include/linux/crc-itu-t.h
+++ b/include/linux/crc-itu-t.h
@@ -4,7 +4,7 @@
*
* Implements the standard CRC ITU-T V.41:
* Width 16
- * Poly 0x1021 (x^16 + x^12 + x^15 + 1)
+ * Poly 0x1021 (x^16 + x^12 + x^5 + 1)
* Init 0
*/
diff --git a/include/linux/random.h b/include/linux/random.h
index fae0c84027fd..20e389a14e5c 100644
--- a/include/linux/random.h
+++ b/include/linux/random.h
@@ -13,7 +13,7 @@
struct notifier_block;
void add_device_randomness(const void *buf, size_t len);
-void add_bootloader_randomness(const void *buf, size_t len);
+void __init add_bootloader_randomness(const void *buf, size_t len);
void add_input_randomness(unsigned int type, unsigned int code,
unsigned int value) __latent_entropy;
void add_interrupt_randomness(int irq) __latent_entropy;
@@ -74,7 +74,6 @@ static inline unsigned long get_random_canary(void)
int __init random_init(const char *command_line);
bool rng_is_initialized(void);
-bool rng_has_arch_random(void);
int wait_for_random_bytes(void);
/* Calls wait_for_random_bytes() and then calls get_random_bytes(buf, nbytes).
diff --git a/lib/crc-itu-t.c b/lib/crc-itu-t.c
index 1974b355c148..1d26a1647da5 100644
--- a/lib/crc-itu-t.c
+++ b/lib/crc-itu-t.c
@@ -7,7 +7,7 @@
#include <linux/module.h>
#include <linux/crc-itu-t.h>
-/** CRC table for the CRC ITU-T V.41 0x1021 (x^16 + x^12 + x^15 + 1) */
+/* CRC table for the CRC ITU-T V.41 0x1021 (x^16 + x^12 + x^5 + 1) */
const u16 crc_itu_t_table[256] = {
0x0000, 0x1021, 0x2042, 0x3063, 0x4084, 0x50a5, 0x60c6, 0x70e7,
0x8108, 0x9129, 0xa14a, 0xb16b, 0xc18c, 0xd1ad, 0xe1ce, 0xf1ef,
diff --git a/lib/vsprintf.c b/lib/vsprintf.c
index fb77f7bfd126..3c1853a9d1c0 100644
--- a/lib/vsprintf.c
+++ b/lib/vsprintf.c
@@ -769,8 +769,7 @@ static inline int __ptr_to_hashval(const void *ptr, unsigned long *hashval_out)
static DECLARE_WORK(enable_ptr_key_work, enable_ptr_key_workfn);
unsigned long flags;
- if (!system_unbound_wq ||
- (!rng_is_initialized() && !rng_has_arch_random()) ||
+ if (!system_unbound_wq || !rng_is_initialized() ||
!spin_trylock_irqsave(&filling, flags))
return -EAGAIN;
diff --git a/tools/testing/selftests/wireguard/qemu/Makefile b/tools/testing/selftests/wireguard/qemu/Makefile
index bca07b93eeb0..7d1b80988d8a 100644
--- a/tools/testing/selftests/wireguard/qemu/Makefile
+++ b/tools/testing/selftests/wireguard/qemu/Makefile
@@ -64,8 +64,8 @@ QEMU_VPORT_RESULT := virtio-serial-device
ifeq ($(HOST_ARCH),$(ARCH))
QEMU_MACHINE := -cpu host -machine virt,gic_version=host,accel=kvm
else
-QEMU_MACHINE := -cpu cortex-a53 -machine virt
-CFLAGS += -march=armv8-a -mtune=cortex-a53
+QEMU_MACHINE := -cpu max -machine virt
+CFLAGS += -march=armv8-a
endif
else ifeq ($(ARCH),aarch64_be)
CHOST := aarch64_be-linux-musl
@@ -76,8 +76,8 @@ QEMU_VPORT_RESULT := virtio-serial-device
ifeq ($(HOST_ARCH),$(ARCH))
QEMU_MACHINE := -cpu host -machine virt,gic_version=host,accel=kvm
else
-QEMU_MACHINE := -cpu cortex-a53 -machine virt
-CFLAGS += -march=armv8-a -mtune=cortex-a53
+QEMU_MACHINE := -cpu max -machine virt
+CFLAGS += -march=armv8-a
endif
else ifeq ($(ARCH),arm)
CHOST := arm-linux-musleabi
@@ -88,8 +88,8 @@ QEMU_VPORT_RESULT := virtio-serial-device
ifeq ($(HOST_ARCH),$(ARCH))
QEMU_MACHINE := -cpu host -machine virt,gic_version=host,accel=kvm
else
-QEMU_MACHINE := -cpu cortex-a15 -machine virt
-CFLAGS += -march=armv7-a -mtune=cortex-a15 -mabi=aapcs-linux
+QEMU_MACHINE := -cpu max -machine virt
+CFLAGS += -march=armv7-a -mabi=aapcs-linux
endif
else ifeq ($(ARCH),armeb)
CHOST := armeb-linux-musleabi
@@ -100,8 +100,8 @@ QEMU_VPORT_RESULT := virtio-serial-device
ifeq ($(HOST_ARCH),$(ARCH))
QEMU_MACHINE := -cpu host -machine virt,gic_version=host,accel=kvm
else
-QEMU_MACHINE := -cpu cortex-a15 -machine virt
-CFLAGS += -march=armv7-a -mabi=aapcs-linux # We don't pass -mtune=cortex-a15 due to a compiler bug on big endian.
+QEMU_MACHINE := -cpu max -machine virt
+CFLAGS += -march=armv7-a -mabi=aapcs-linux
LDFLAGS += -Wl,--be8
endif
else ifeq ($(ARCH),x86_64)
@@ -112,8 +112,7 @@ KERNEL_BZIMAGE := $(KERNEL_BUILD_PATH)/arch/x86/boot/bzImage
ifeq ($(HOST_ARCH),$(ARCH))
QEMU_MACHINE := -cpu host -machine q35,accel=kvm
else
-QEMU_MACHINE := -cpu Skylake-Server -machine q35
-CFLAGS += -march=skylake-avx512
+QEMU_MACHINE := -cpu max -machine q35
endif
else ifeq ($(ARCH),i686)
CHOST := i686-linux-musl
@@ -123,8 +122,7 @@ KERNEL_BZIMAGE := $(KERNEL_BUILD_PATH)/arch/x86/boot/bzImage
ifeq ($(subst x86_64,i686,$(HOST_ARCH)),$(ARCH))
QEMU_MACHINE := -cpu host -machine q35,accel=kvm
else
-QEMU_MACHINE := -cpu coreduo -machine q35
-CFLAGS += -march=prescott
+QEMU_MACHINE := -cpu max -machine q35
endif
else ifeq ($(ARCH),mips64)
CHOST := mips64-linux-musl
@@ -182,7 +180,7 @@ KERNEL_BZIMAGE := $(KERNEL_BUILD_PATH)/vmlinux
ifeq ($(HOST_ARCH),$(ARCH))
QEMU_MACHINE := -cpu host,accel=kvm -machine pseries
else
-QEMU_MACHINE := -machine pseries
+QEMU_MACHINE := -machine pseries -device spapr-rng,rng=rng -object rng-random,id=rng
endif
else ifeq ($(ARCH),powerpc64le)
CHOST := powerpc64le-linux-musl
@@ -192,7 +190,7 @@ KERNEL_BZIMAGE := $(KERNEL_BUILD_PATH)/vmlinux
ifeq ($(HOST_ARCH),$(ARCH))
QEMU_MACHINE := -cpu host,accel=kvm -machine pseries
else
-QEMU_MACHINE := -machine pseries
+QEMU_MACHINE := -machine pseries -device spapr-rng,rng=rng -object rng-random,id=rng
endif
else ifeq ($(ARCH),powerpc)
CHOST := powerpc-linux-musl
@@ -247,7 +245,7 @@ QEMU_VPORT_RESULT := virtio-serial-ccw
ifeq ($(HOST_ARCH),$(ARCH))
QEMU_MACHINE := -cpu host,accel=kvm -machine s390-ccw-virtio -append $(KERNEL_CMDLINE)
else
-QEMU_MACHINE := -machine s390-ccw-virtio -append $(KERNEL_CMDLINE)
+QEMU_MACHINE := -cpu max -machine s390-ccw-virtio -append $(KERNEL_CMDLINE)
endif
else
$(error I only build: x86_64, i686, arm, armeb, aarch64, aarch64_be, mips, mipsel, mips64, mips64el, powerpc64, powerpc64le, powerpc, m68k, riscv64, riscv32, s390x)
diff --git a/tools/testing/selftests/wireguard/qemu/init.c b/tools/testing/selftests/wireguard/qemu/init.c
index 2a0f48fac925..c9e128436546 100644
--- a/tools/testing/selftests/wireguard/qemu/init.c
+++ b/tools/testing/selftests/wireguard/qemu/init.c
@@ -21,6 +21,7 @@
#include <sys/utsname.h>
#include <sys/sendfile.h>
#include <sys/sysmacros.h>
+#include <sys/random.h>
#include <linux/random.h>
#include <linux/version.h>
@@ -58,6 +59,8 @@ static void seed_rng(void)
{
int bits = 256, fd;
+ if (!getrandom(NULL, 0, GRND_NONBLOCK))
+ return;
pretty_message("[+] Fake seeding RNG...");
fd = open("/dev/random", O_WRONLY);
if (fd < 0)
diff --git a/tools/testing/selftests/wireguard/qemu/kernel.config b/tools/testing/selftests/wireguard/qemu/kernel.config
index a9b5a520a1d2..bad88f4b0a03 100644
--- a/tools/testing/selftests/wireguard/qemu/kernel.config
+++ b/tools/testing/selftests/wireguard/qemu/kernel.config
@@ -31,6 +31,7 @@ CONFIG_TTY=y
CONFIG_BINFMT_ELF=y
CONFIG_BINFMT_SCRIPT=y
CONFIG_VDSO=y
+CONFIG_STRICT_KERNEL_RWX=y
CONFIG_VIRTUALIZATION=y
CONFIG_HYPERVISOR_GUEST=y
CONFIG_PARAVIRT=y
@@ -65,6 +66,8 @@ CONFIG_PROC_FS=y
CONFIG_PROC_SYSCTL=y
CONFIG_SYSFS=y
CONFIG_TMPFS=y
+CONFIG_RANDOM_TRUST_CPU=y
+CONFIG_RANDOM_TRUST_BOOTLOADER=y
CONFIG_CONSOLE_LOGLEVEL_DEFAULT=15
CONFIG_LOG_BUF_SHIFT=18
CONFIG_PRINTK_TIME=y