sched_ext: Maintain an online cid mask in the scheduler arenagrafted

Schedulers on the default cid mapping treat [0, nr_online_cids) as the
online set and restart on hotplug. Schedulers that install their own mapping
with scx_bpf_cid_override() have no way to learn which cids are online: the
count no longer identifies members and the CPU-form cpumask is unusable from
cid programs. This is an obvious hole in the cid API.

Add scx_bpf_online_cmask(), a kernel-maintained cmask in the scheduler's
arena, allocated alongside the per-CPU scratch masks and populated after the
cid mapping is finalized and before ops.init(), for child schedulers too.
The pointer stays valid through ops.exit() with no reference to take. It is
the arena offset as a void pointer, the same form struct_ops arena arguments
arrive in. The verifier types the void return as a scalar for the program's
arena cast.

The mask follows the SCX hotplug notifications: seeded from cpu_active_mask
and updated before ops.cid_online/offline() runs, so it lags cpu_online_mask
only inside a hotplug transition. Updates walk the scheduler list under the
lock that also serializes unlinking. Reads are live, not atomic snapshots.
Root initialization excludes hotplug.

v2: Reworded the getter kerneldoc (Andrea Righi).

Signed-off-by: Tejun Heo <tj@kernel.org>
Reviewed-by: Andrea Righi <arighi@nvidia.com>

1 files changed, 386 insertions, 0 deletions

diff --git a/lib/crypto/Makefile b/lib/crypto/Makefile
new file mode 100644
index 000000000..f1e9bf897
--- /dev/null
+++ b/lib/crypto/Makefile
@@ -0,0 +1,386 @@
+# SPDX-License-Identifier: GPL-2.0
+
+aflags-thumb2-$(CONFIG_THUMB2_KERNEL)  := -U__thumb2__ -D__thumb2__=1
+
+quiet_cmd_perlasm = PERLASM $@
+      cmd_perlasm = $(PERL) $(<) > $(@)
+
+quiet_cmd_perlasm_with_args = PERLASM $@
+      cmd_perlasm_with_args = $(PERL) $(<) void $(@)
+
+ppc64-perlasm-flavour-y := linux-ppc64
+ppc64-perlasm-flavour-$(CONFIG_PPC64_ELF_ABI_V2) := linux-ppc64-elfv2
+ppc64-perlasm-flavour-$(CONFIG_CPU_LITTLE_ENDIAN) := linux-ppc64le
+
+obj-$(CONFIG_KUNIT)				+= tests/
+
+obj-$(CONFIG_CRYPTO_HASH_INFO)			+= hash_info.o
+
+obj-$(CONFIG_CRYPTO_LIB_UTILS)			+= libcryptoutils.o
+libcryptoutils-y				:= memneq.o utils.o
+
+################################################################################
+
+obj-$(CONFIG_CRYPTO_LIB_AES) += libaes.o
+libaes-y := aes.o
+ifeq ($(CONFIG_CRYPTO_LIB_AES_ARCH),y)
+CFLAGS_aes.o += -I$(src)/$(SRCARCH)
+
+libaes-$(CONFIG_ARM) += arm/aes-cipher-core.o
+libaes-$(CONFIG_ARM64) += arm64/aes-cipher-core.o \
+			  arm64/aes-ce-core.o \
+			  arm64/aes-ce.o \
+			  arm64/aes-neon.o
+
+ifeq ($(CONFIG_PPC),y)
+ifeq ($(CONFIG_SPE),y)
+libaes-y += powerpc/aes-spe-core.o \
+	    powerpc/aes-spe-keys.o \
+	    powerpc/aes-spe-modes.o \
+	    powerpc/aes-tab-4k.o
+else
+libaes-y += powerpc/aesp8-ppc.o
+quiet_cmd_perlasm_aes = PERLASM $@
+      cmd_perlasm_aes = $(PERL) $< $(ppc64-perlasm-flavour-y) $@
+# Use if_changed instead of cmd, in case the flavour changed.
+$(obj)/powerpc/aesp8-ppc.S: $(src)/powerpc/aesp8-ppc.pl FORCE
+	$(call if_changed,perlasm_aes)
+targets += powerpc/aesp8-ppc.S
+OBJECT_FILES_NON_STANDARD_powerpc/aesp8-ppc.o := y
+endif # !CONFIG_SPE
+endif # CONFIG_PPC
+
+libaes-$(CONFIG_RISCV) += riscv/aes-riscv64-zvkned.o
+libaes-$(CONFIG_SPARC) += sparc/aes_asm.o
+libaes-$(CONFIG_X86) += x86/aes-aesni.o
+endif # CONFIG_CRYPTO_LIB_AES_ARCH
+
+# clean-files must be defined unconditionally
+clean-files += powerpc/aesp8-ppc.S
+
+################################################################################
+
+obj-$(CONFIG_CRYPTO_LIB_AESCFB)			+= libaescfb.o
+libaescfb-y					:= aescfb.o
+
+obj-$(CONFIG_CRYPTO_LIB_AESGCM)			+= libaesgcm.o
+libaesgcm-y					:= aesgcm.o
+
+obj-$(CONFIG_CRYPTO_LIB_ARC4)			+= libarc4.o
+libarc4-y					:= arc4.o
+
+obj-$(CONFIG_CRYPTO_LIB_GF128MUL)		+= gf128mul.o
+
+################################################################################
+
+obj-$(CONFIG_CRYPTO_LIB_BLAKE2B) += libblake2b.o
+libblake2b-y := blake2b.o
+ifeq ($(CONFIG_CRYPTO_LIB_BLAKE2B_ARCH),y)
+CFLAGS_blake2b.o += -I$(src)/$(SRCARCH)
+libblake2b-$(CONFIG_ARM) += arm/blake2b-neon-core.o
+endif # CONFIG_CRYPTO_LIB_BLAKE2B_ARCH
+
+################################################################################
+
+# blake2s is used by the /dev/random driver which is always builtin
+obj-y += blake2s.o
+ifeq ($(CONFIG_CRYPTO_LIB_BLAKE2S_ARCH),y)
+CFLAGS_blake2s.o += -I$(src)/$(SRCARCH)
+obj-$(CONFIG_ARM) += arm/blake2s-core.o
+obj-$(CONFIG_X86) += x86/blake2s-core.o
+endif
+
+################################################################################
+
+# chacha20_block() is used by the /dev/random driver which is always builtin
+obj-y += chacha-block-generic.o
+
+obj-$(CONFIG_CRYPTO_LIB_CHACHA) += libchacha.o
+libchacha-y := chacha.o
+
+ifeq ($(CONFIG_CRYPTO_LIB_CHACHA_ARCH),y)
+CFLAGS_chacha.o += -I$(src)/$(SRCARCH)
+
+ifeq ($(CONFIG_ARM),y)
+libchacha-y += arm/chacha-scalar-core.o
+libchacha-$(CONFIG_KERNEL_MODE_NEON) += arm/chacha-neon-core.o
+endif
+
+libchacha-$(CONFIG_ARM64) += arm64/chacha-neon-core.o
+
+ifeq ($(CONFIG_MIPS),y)
+libchacha-y += mips/chacha-core.o
+AFLAGS_mips/chacha-core.o += -O2 # needed to fill branch delay slots
+endif
+
+libchacha-$(CONFIG_PPC) += powerpc/chacha-p10le-8x.o
+libchacha-$(CONFIG_RISCV) += riscv/chacha-riscv64-zvkb.o
+libchacha-$(CONFIG_S390) += s390/chacha-s390.o
+libchacha-$(CONFIG_X86) += x86/chacha-ssse3-x86_64.o \
+			   x86/chacha-avx2-x86_64.o \
+			   x86/chacha-avx512vl-x86_64.o
+endif # CONFIG_CRYPTO_LIB_CHACHA_ARCH
+
+################################################################################
+
+obj-$(CONFIG_CRYPTO_LIB_CHACHA20POLY1305)	+= libchacha20poly1305.o
+libchacha20poly1305-y				+= chacha20poly1305.o
+
+################################################################################
+
+obj-$(CONFIG_CRYPTO_LIB_CURVE25519) += libcurve25519.o
+libcurve25519-y := curve25519.o
+
+# Disable GCOV in odd or sensitive code
+GCOV_PROFILE_curve25519.o := n
+
+ifeq ($(CONFIG_ARCH_SUPPORTS_INT128),y)
+libcurve25519-$(CONFIG_CRYPTO_LIB_CURVE25519_GENERIC) += curve25519-hacl64.o
+else
+libcurve25519-$(CONFIG_CRYPTO_LIB_CURVE25519_GENERIC) += curve25519-fiat32.o
+endif
+# clang versions prior to 18 may blow out the stack with KASAN
+ifeq ($(CONFIG_CC_IS_CLANG)_$(call clang-min-version, 180000),y_)
+KASAN_SANITIZE_curve25519-hacl64.o := n
+endif
+
+ifeq ($(CONFIG_CRYPTO_LIB_CURVE25519_ARCH),y)
+CFLAGS_curve25519.o += -I$(src)/$(SRCARCH)
+libcurve25519-$(CONFIG_ARM) += arm/curve25519-core.o
+libcurve25519-$(CONFIG_PPC) += powerpc/curve25519-ppc64le_asm.o
+endif
+
+################################################################################
+
+obj-$(CONFIG_CRYPTO_LIB_DES)			+= libdes.o
+libdes-y					:= des.o
+
+################################################################################
+
+obj-$(CONFIG_CRYPTO_LIB_GF128HASH) += libgf128hash.o
+libgf128hash-y := gf128hash.o
+ifeq ($(CONFIG_CRYPTO_LIB_GF128HASH_ARCH),y)
+CFLAGS_gf128hash.o += -I$(src)/$(SRCARCH)
+libgf128hash-$(CONFIG_ARM) += arm/ghash-neon-core.o
+libgf128hash-$(CONFIG_ARM64) += arm64/ghash-neon-core.o \
+				arm64/polyval-ce-core.o
+
+ifeq ($(CONFIG_PPC),y)
+libgf128hash-y += powerpc/ghashp8-ppc.o
+quiet_cmd_perlasm_ghash = PERLASM $@
+      cmd_perlasm_ghash = $(PERL) $< $(ppc64-perlasm-flavour-y) $@
+$(obj)/powerpc/ghashp8-ppc.S: $(src)/powerpc/ghashp8-ppc.pl FORCE
+	$(call if_changed,perlasm_ghash)
+targets += powerpc/ghashp8-ppc.S
+OBJECT_FILES_NON_STANDARD_powerpc/ghashp8-ppc.o := y
+endif
+
+libgf128hash-$(CONFIG_RISCV) += riscv/ghash-riscv64-zvkg.o
+libgf128hash-$(CONFIG_X86) += x86/ghash-pclmul.o \
+			      x86/polyval-pclmul-avx.o
+endif # CONFIG_CRYPTO_LIB_GF128HASH_ARCH
+
+# clean-files must be defined unconditionally
+clean-files += powerpc/ghashp8-ppc.S
+
+################################################################################
+
+obj-$(CONFIG_CRYPTO_LIB_MD5) += libmd5.o
+libmd5-y := md5.o
+
+################################################################################
+
+obj-$(CONFIG_CRYPTO_LIB_MLDSA) += libmldsa.o
+libmldsa-y := mldsa.o
+
+################################################################################
+
+obj-$(CONFIG_CRYPTO_LIB_NH) += libnh.o
+libnh-y := nh.o
+ifeq ($(CONFIG_CRYPTO_LIB_NH_ARCH),y)
+CFLAGS_nh.o += -I$(src)/$(SRCARCH)
+libnh-$(CONFIG_ARM) += arm/nh-neon-core.o
+libnh-$(CONFIG_ARM64) += arm64/nh-neon-core.o
+libnh-$(CONFIG_X86) += x86/nh-sse2.o x86/nh-avx2.o
+endif
+
+################################################################################
+
+obj-$(CONFIG_CRYPTO_LIB_POLY1305) += libpoly1305.o
+libpoly1305-y := poly1305.o
+ifeq ($(CONFIG_ARCH_SUPPORTS_INT128),y)
+libpoly1305-$(CONFIG_CRYPTO_LIB_POLY1305_GENERIC) += poly1305-donna64.o
+else
+libpoly1305-$(CONFIG_CRYPTO_LIB_POLY1305_GENERIC) += poly1305-donna32.o
+endif
+
+ifeq ($(CONFIG_CRYPTO_LIB_POLY1305_ARCH),y)
+CFLAGS_poly1305.o += -I$(src)/$(SRCARCH)
+
+ifeq ($(CONFIG_ARM),y)
+libpoly1305-y += arm/poly1305-core.o
+$(obj)/arm/poly1305-core.S: $(src)/arm/poly1305-armv4.pl
+	$(call cmd,perlasm)
+# massage the perlasm code a bit so we only get the NEON routine if we need it
+poly1305-aflags-$(CONFIG_CPU_V7) := -U__LINUX_ARM_ARCH__ -D__LINUX_ARM_ARCH__=5
+poly1305-aflags-$(CONFIG_KERNEL_MODE_NEON) := -U__LINUX_ARM_ARCH__ -D__LINUX_ARM_ARCH__=7
+AFLAGS_arm/poly1305-core.o += $(poly1305-aflags-y) $(aflags-thumb2-y)
+endif
+
+ifeq ($(CONFIG_ARM64),y)
+libpoly1305-y += arm64/poly1305-core.o
+$(obj)/arm64/poly1305-core.S: $(src)/arm64/poly1305-armv8.pl
+	$(call cmd,perlasm_with_args)
+endif
+
+ifeq ($(CONFIG_MIPS),y)
+libpoly1305-y += mips/poly1305-core.o
+poly1305-perlasm-flavour-$(CONFIG_32BIT) := o32
+poly1305-perlasm-flavour-$(CONFIG_64BIT) := 64
+quiet_cmd_perlasm_poly1305 = PERLASM $@
+      cmd_perlasm_poly1305 = $(PERL) $< $(poly1305-perlasm-flavour-y) $@
+# Use if_changed instead of cmd, in case the flavour changed.
+$(obj)/mips/poly1305-core.S: $(src)/mips/poly1305-mips.pl FORCE
+	$(call if_changed,perlasm_poly1305)
+targets += mips/poly1305-core.S
+endif
+
+libpoly1305-$(CONFIG_PPC) += powerpc/poly1305-p10le_64.o
+
+ifeq ($(CONFIG_RISCV),y)
+libpoly1305-y += riscv/poly1305-core.o
+poly1305-perlasm-flavour-$(CONFIG_32BIT) := 32
+poly1305-perlasm-flavour-$(CONFIG_64BIT) := 64
+quiet_cmd_perlasm_poly1305 = PERLASM $@
+      cmd_perlasm_poly1305 = $(PERL) $< $(poly1305-perlasm-flavour-y) $@
+# Use if_changed instead of cmd, in case the flavour changed.
+$(obj)/riscv/poly1305-core.S: $(src)/riscv/poly1305-riscv.pl FORCE
+	$(call if_changed,perlasm_poly1305)
+targets += riscv/poly1305-core.S
+AFLAGS_riscv/poly1305-core.o += -Dpoly1305_init=poly1305_block_init
+endif
+
+ifeq ($(CONFIG_X86),y)
+libpoly1305-y += x86/poly1305-x86_64-cryptogams.o
+$(obj)/x86/poly1305-x86_64-cryptogams.S: $(src)/x86/poly1305-x86_64-cryptogams.pl
+	$(call cmd,perlasm)
+endif
+
+endif # CONFIG_CRYPTO_LIB_POLY1305_ARCH
+
+# clean-files must be defined unconditionally
+clean-files += arm/poly1305-core.S \
+	       arm64/poly1305-core.S \
+	       mips/poly1305-core.S \
+	       riscv/poly1305-core.S \
+	       x86/poly1305-x86_64-cryptogams.S
+
+################################################################################
+
+obj-$(CONFIG_CRYPTO_LIB_SHA1) += libsha1.o
+libsha1-y := sha1.o
+ifeq ($(CONFIG_CRYPTO_LIB_SHA1_ARCH),y)
+CFLAGS_sha1.o += -I$(src)/$(SRCARCH)
+ifeq ($(CONFIG_ARM),y)
+libsha1-y += arm/sha1-armv4-large.o
+libsha1-$(CONFIG_KERNEL_MODE_NEON) += arm/sha1-armv7-neon.o \
+				      arm/sha1-ce-core.o
+endif
+libsha1-$(CONFIG_ARM64) += arm64/sha1-ce-core.o
+ifeq ($(CONFIG_PPC),y)
+libsha1-y += powerpc/sha1-powerpc-asm.o
+libsha1-$(CONFIG_SPE) += powerpc/sha1-spe-asm.o
+endif
+libsha1-$(CONFIG_SPARC) += sparc/sha1_asm.o
+libsha1-$(CONFIG_X86) += x86/sha1-ssse3-and-avx.o \
+			 x86/sha1-avx2-asm.o \
+			 x86/sha1-ni-asm.o
+endif # CONFIG_CRYPTO_LIB_SHA1_ARCH
+
+################################################################################
+
+obj-$(CONFIG_CRYPTO_LIB_SHA256) += libsha256.o
+libsha256-y := sha256.o
+ifeq ($(CONFIG_CRYPTO_LIB_SHA256_ARCH),y)
+CFLAGS_sha256.o += -I$(src)/$(SRCARCH)
+
+ifeq ($(CONFIG_ARM),y)
+libsha256-y += arm/sha256-ce.o arm/sha256-core.o
+$(obj)/arm/sha256-core.S: $(src)/arm/sha256-armv4.pl
+	$(call cmd,perlasm)
+AFLAGS_arm/sha256-core.o += $(aflags-thumb2-y)
+endif
+
+ifeq ($(CONFIG_ARM64),y)
+libsha256-y += arm64/sha256-ce.o arm64/sha256-core.o
+$(obj)/arm64/sha256-core.S: $(src)/arm64/sha2-armv8.pl
+	$(call cmd,perlasm_with_args)
+endif
+
+libsha256-$(CONFIG_PPC) += powerpc/sha256-spe-asm.o
+libsha256-$(CONFIG_RISCV) += riscv/sha256-riscv64-zvknha_or_zvknhb-zvkb.o
+libsha256-$(CONFIG_SPARC) += sparc/sha256_asm.o
+libsha256-$(CONFIG_X86) += x86/sha256-ssse3-asm.o \
+			   x86/sha256-avx-asm.o \
+			   x86/sha256-avx2-asm.o \
+			   x86/sha256-ni-asm.o
+endif # CONFIG_CRYPTO_LIB_SHA256_ARCH
+
+################################################################################
+
+obj-$(CONFIG_CRYPTO_LIB_SHA512) += libsha512.o
+libsha512-y := sha512.o
+ifeq ($(CONFIG_CRYPTO_LIB_SHA512_ARCH),y)
+CFLAGS_sha512.o += -I$(src)/$(SRCARCH)
+
+ifeq ($(CONFIG_ARM),y)
+libsha512-y += arm/sha512-core.o
+$(obj)/arm/sha512-core.S: $(src)/arm/sha512-armv4.pl
+	$(call cmd,perlasm)
+AFLAGS_arm/sha512-core.o += $(aflags-thumb2-y)
+endif
+
+ifeq ($(CONFIG_ARM64),y)
+libsha512-y += arm64/sha512-ce-core.o arm64/sha512-core.o
+$(obj)/arm64/sha512-core.S: $(src)/arm64/sha2-armv8.pl
+	$(call cmd,perlasm_with_args)
+endif
+
+libsha512-$(CONFIG_RISCV) += riscv/sha512-riscv64-zvknhb-zvkb.o
+libsha512-$(CONFIG_SPARC) += sparc/sha512_asm.o
+libsha512-$(CONFIG_X86) += x86/sha512-ssse3-asm.o \
+			   x86/sha512-avx-asm.o \
+			   x86/sha512-avx2-asm.o
+endif # CONFIG_CRYPTO_LIB_SHA512_ARCH
+
+################################################################################
+
+obj-$(CONFIG_CRYPTO_LIB_SHA3) += libsha3.o
+libsha3-y := sha3.o
+
+ifeq ($(CONFIG_CRYPTO_LIB_SHA3_ARCH),y)
+CFLAGS_sha3.o += -I$(src)/$(SRCARCH)
+libsha3-$(CONFIG_ARM64) += arm64/sha3-ce-core.o
+endif # CONFIG_CRYPTO_LIB_SHA3_ARCH
+
+################################################################################
+
+obj-$(CONFIG_CRYPTO_LIB_SM3) += libsm3.o
+libsm3-y := sm3.o
+ifeq ($(CONFIG_CRYPTO_LIB_SM3_ARCH),y)
+CFLAGS_sm3.o += -I$(src)/$(SRCARCH)
+libsm3-$(CONFIG_ARM64) += arm64/sm3-ce-core.o \
+			  arm64/sm3-neon-core.o
+libsm3-$(CONFIG_RISCV) += riscv/sm3-riscv64-zvksh-zvkb.o
+libsm3-$(CONFIG_X86) += x86/sm3-avx-asm_64.o
+endif # CONFIG_CRYPTO_LIB_SM3_ARCH
+
+################################################################################
+
+obj-$(CONFIG_MPILIB) += mpi/
+
+obj-$(CONFIG_CRYPTO_SELFTESTS_FULL)		+= simd.o
+
+# clean-files must be defined unconditionally
+clean-files += arm/sha256-core.S arm/sha512-core.S
+clean-files += arm64/sha256-core.S arm64/sha512-core.S