Merge tag 'random-5.19-rc2-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/crng/random

Pull random number generator fixes from Jason Donenfeld:

 - A fix for a 5.19 regression for a case in which early device tree
   initializes the RNG, which flips a static branch.

   On most plaforms, jump labels aren't initialized until much later, so
   this caused splats. On a few mailing list threads, we cooked up easy
   fixes for arm64, arm32, and risc-v. But then things looked slightly
   more involved for xtensa, powerpc, arc, and mips. And at that point,
   when we're patching 7 architectures in a place before the console is
   even available, it seems like the cost/risk just wasn't worth it.

   So random.c works around it now by checking the already exported
   `static_key_initialized` boolean, as though somebody already ran into
   this issue in the past. I'm not super jazzed about that; it'd be
   prettier to not have to complicate downstream code. But I suppose
   it's practical.

 - A few small code nits and adding a missing __init annotation.

 - A change to the default config values to use the cpu and bootloader's
   seeds for initializing the RNG earlier.

   This brings them into line with what all the distros do (Fedora/RHEL,
   Debian, Ubuntu, Gentoo, Arch, NixOS, Alpine, SUSE, and Void... at
   least), and moreover will now give us test coverage in various test
   beds that might have caught the above device tree bug earlier.

 - A change to WireGuard CI's configuration to increase test coverage
   around the RNG.

 - A documentation comment fix to unrelated maintainerless CRC code that
   I was asked to take, I guess because it has to do with polynomials
   (which the RNG thankfully no longer uses).

* tag 'random-5.19-rc2-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/crng/random:
  wireguard: selftests: use maximum cpu features and allow rng seeding
  random: remove rng_has_arch_random()
  random: credit cpu and bootloader seeds by default
  random: do not use jump labels before they are initialized
  random: account for arch randomness in bits
  random: mark bootloader randomness code as __init
  random: avoid checking crng_ready() twice in random_init()
  crc-itu-t: fix typo in CRC ITU-T polynomial comment

3 files changed, 19 insertions, 15 deletions

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