$(Q)$(RM) -r $(TEST_KMODS)
$(Q)$(RM) -r $(EXTRA_CLEAN)
$(Q)$(MAKE) -C test_kmods clean
+ $(Q)$(MAKE) -C libarena clean
$(Q)$(MAKE) docs-clean
endef
LINKED_BPF_SRCS := $(patsubst %.bpf.o,%.c,$(LINKED_BPF_OBJS))
HEADERS_FOR_BPF_OBJS := $(wildcard $(BPFDIR)/*.bpf.h) \
+ $(wildcard $(CURDIR)/libarena/include/*.[ch]) \
$(addprefix $(BPFDIR)/, bpf_core_read.h \
bpf_endian.h \
bpf_helpers.h \
echo "};"; \
echo "unsigned int test_progs_verification_cert_len = $$(wc -c < $<);") > $@
+LIBARENA_MAKE_ARGS = \
+ BPFTOOL="$(BPFTOOL)" \
+ INCLUDE_DIR="$(INCLUDE_DIR)" \
+ LIBBPF_INCLUDE="$(HOST_INCLUDE_DIR)" \
+ BPFOBJ="$(BPFOBJ)" \
+ LDLIBS="$(LDLIBS) -lzstd" \
+ CLANG="$(CLANG)" \
+ BPF_CFLAGS="$(BPF_CFLAGS) $(CLANG_CFLAGS)" \
+ BPF_TARGET_ENDIAN="$(BPF_TARGET_ENDIAN)" \
+ Q="$(Q)"
+
+LIBARENA_BPF_DEPS := $(wildcard libarena/Makefile \
+ libarena/include/* \
+ libarena/include/libarena/* \
+ libarena/src/* \
+ libarena/selftests/* \
+ libarena/*.bpf.o)
+
+LIBARENA_SKEL := libarena/libarena.skel.h
+
+$(LIBARENA_SKEL): $(INCLUDE_DIR)/vmlinux.h $(BPFOBJ) $(LIBARENA_BPF_DEPS)
+ +$(MAKE) -C libarena libarena.skel.h $(LIBARENA_MAKE_ARGS)
+
# Define test_progs test runner.
TRUNNER_TESTS_DIR := prog_tests
TRUNNER_BPF_PROGS_DIR := progs
rsync -a $(OUTPUT)/$$DIR/*.bpf.o $(INSTALL_PATH)/$$DIR;\
done
endef
+
+libarena: $(LIBARENA_SKEL)
--- /dev/null
+# SPDX-License-Identifier: LGPL-2.1 OR BSD-2-Clause
+# Copyright (c) 2026 Meta Platforms, Inc. and affiliates.
+
+.PHONY: clean
+
+# Defaults for standalone builds
+
+CLANG ?= clang
+BPFTOOL ?= bpftool
+LDLIBS ?= -lbpf -lelf -lz -lrt -lpthread -lzstd
+
+ifeq ($(V),1)
+Q =
+msg =
+else
+Q ?= @
+msg = @printf ' %-8s%s %s%s\n' "$(1)" "$(if $(2), [$(2)])" "$(notdir $(3))" "$(if $(4), $(4))";
+endif
+
+IS_LITTLE_ENDIAN = $(shell $(CC) -dM -E - </dev/null | \
+ grep 'define __BYTE_ORDER__ __ORDER_LITTLE_ENDIAN__')
+BPF_TARGET_ENDIAN ?= $(if $(IS_LITTLE_ENDIAN),--target=bpfel,--target=bpfeb)
+
+LIBARENA=$(abspath .)
+BPFDIR=$(abspath $(LIBARENA)/..)
+
+INCLUDE_DIR ?= $(BPFDIR)/tools/include
+LIBBPF_INCLUDE ?= $(INCLUDE_DIR)
+
+# Scan src/ and selftests/ to generate the final binaries
+LIBARENA_SOURCES = $(wildcard $(LIBARENA)/src/*.bpf.c) $(wildcard $(LIBARENA)/selftests/*.bpf.c)
+LIBARENA_OBJECTS = $(notdir $(LIBARENA_SOURCES:.bpf.c=.bpf.o))
+
+INCLUDES = -I$(LIBARENA)/include -I$(BPFDIR)
+ifneq ($(INCLUDE_DIR),)
+INCLUDES += -I$(INCLUDE_DIR)
+endif
+ifneq ($(LIBBPF_INCLUDE),)
+INCLUDES += -I$(LIBBPF_INCLUDE)
+endif
+
+# ENABLE_ATOMICS_TESTS required because we use arena spinlocks
+override BPF_CFLAGS += -DENABLE_ATOMICS_TESTS
+override BPF_CFLAGS += -O2 -g
+override BPF_CFLAGS += -Wno-incompatible-pointer-types-discards-qualifiers
+# Required for suppressing harmless vmlinux.h-related warnings.
+override BPF_CFLAGS += -Wno-missing-declarations
+override BPF_CFLAGS += $(INCLUDES)
+
+CFLAGS = -O2 -no-pie
+CFLAGS += $(INCLUDES)
+
+vpath %.bpf.c $(LIBARENA)/src $(LIBARENA)/selftests
+vpath %.c $(LIBARENA)/src $(LIBARENA)/selftests
+
+libarena.skel.h: libarena.bpf.o
+ $(call msg,GEN-SKEL,libarena,$@)
+ $(Q)$(BPFTOOL) gen skeleton $< name "libarena" > $@
+
+libarena.bpf.o: $(LIBARENA_OBJECTS)
+ $(call msg,GEN-OBJ,libarena,$@)
+ $(Q)$(BPFTOOL) gen object $@ $^
+
+%.bpf.o: %.bpf.c
+ $(call msg,CLNG-BPF,libarena,$@)
+ $(Q)$(CLANG) $(BPF_CFLAGS) $(BPF_TARGET_ENDIAN) -c $< -o $@
+
+clean:
+ $(Q)rm -f *.skel.h *.bpf.o
--- /dev/null
+// SPDX-License-Identifier: LGPL-2.1 OR BSD-2-Clause
+/* Copyright (c) 2026 Meta Platforms, Inc. and affiliates. */
+#pragma once
+
+#ifdef __BPF__
+
+#include <vmlinux.h>
+
+#include "../../bpf_arena_common.h"
+#include "../../progs/bpf_arena_spin_lock.h"
+
+#include <asm-generic/errno.h>
+
+#ifndef __BPF_FEATURE_ADDR_SPACE_CAST
+#error "Arena allocators require bpf_addr_space_cast feature"
+#endif
+
+#define arena_stdout(fmt, ...) bpf_stream_printk(1, (fmt), ##__VA_ARGS__)
+#define arena_stderr(fmt, ...) bpf_stream_printk(2, (fmt), ##__VA_ARGS__)
+
+#ifndef __maybe_unused
+#define __maybe_unused __attribute__((__unused__))
+#endif
+
+#define private(name) SEC(".data." #name) __hidden __attribute__((aligned(8)))
+
+#define ARENA_PAGES (1UL << (32 - __builtin_ffs(__PAGE_SIZE) + 1))
+
+struct {
+ __uint(type, BPF_MAP_TYPE_ARENA);
+ __uint(map_flags, BPF_F_MMAPABLE);
+ __uint(max_entries, ARENA_PAGES); /* number of pages */
+#if defined(__TARGET_ARCH_arm64) || defined(__aarch64__)
+ __ulong(map_extra, (1ull << 32)); /* start of mmap() region */
+#else
+ __ulong(map_extra, (1ull << 44)); /* start of mmap() region */
+#endif
+} arena __weak SEC(".maps");
+
+/*
+ * This is a variable used to aid verification. The may_goto directive
+ * permits open-coded for loops, but requires that the index variable is
+ * imprecise. To force the variable to be imprecise, initialize it with
+ * the opaque volatile variable 0 instead of the constant 0.
+ */
+extern const volatile u32 zero;
+
+int arena_fls(__u64 word);
+
+#else /* ! __BPF__ */
+
+#include <stdint.h>
+
+#define __arena
+
+typedef uint8_t u8;
+typedef uint16_t u16;
+typedef uint32_t u32;
+typedef uint64_t u64;
+typedef int8_t s8;
+typedef int16_t s16;
+typedef int32_t s32;
+typedef int64_t s64;
+
+/* Dummy "definition" for userspace. */
+#define arena_spinlock_t int
+
+#endif /* __BPF__ */
+
+struct arena_get_info_args {
+ void __arena *arena_base;
+};
+
+struct arena_alloc_reserve_args {
+ u64 nr_pages;
+};
+
+/* Reasonable default number of pages reserved by arena_alloc_reserve. */
+#define ARENA_RESERVE_PAGES_DFL (8)
--- /dev/null
+// SPDX-License-Identifier: LGPL-2.1 OR BSD-2-Clause
+/* Copyright (c) 2026 Meta Platforms, Inc. and affiliates. */
+#pragma once
+
+#include <errno.h>
+#include <stdlib.h>
+#include <unistd.h>
+#include <sys/mman.h>
+
+#include <bpf/libbpf.h>
+#include <bpf/bpf.h>
+
+static inline int libarena_run_prog(int prog_fd)
+{
+ LIBBPF_OPTS(bpf_test_run_opts, opts);
+ int ret;
+
+ ret = bpf_prog_test_run_opts(prog_fd, &opts);
+ if (ret)
+ return ret;
+
+ return opts.retval;
+}
+
+static inline bool libarena_is_test_prog(const char *name)
+{
+ return strstr(name, "test_") == name;
+}
+
+static inline int libarena_run_prog_args(int prog_fd, void *args, size_t argsize)
+{
+ LIBBPF_OPTS(bpf_test_run_opts, opts);
+ int ret;
+
+ opts.ctx_in = args;
+ opts.ctx_size_in = argsize;
+
+ ret = bpf_prog_test_run_opts(prog_fd, &opts);
+
+ return ret ?: opts.retval;
+}
+
+static inline int libarena_get_arena_base(int arena_get_info_fd,
+ void **arena_base)
+{
+ LIBBPF_OPTS(bpf_test_run_opts, opts);
+ struct arena_get_info_args args = { .arena_base = NULL };
+ int ret;
+
+ opts.ctx_in = &args;
+ opts.ctx_size_in = sizeof(args);
+
+ ret = bpf_prog_test_run_opts(arena_get_info_fd, &opts);
+ if (ret)
+ return ret;
+ if (opts.retval)
+ return opts.retval;
+
+ *arena_base = args.arena_base;
+ return 0;
+}
+
+static inline int libarena_get_globals_pages(int arena_get_globals_fd,
+ size_t arena_all_pages,
+ u64 *globals_pages)
+{
+ size_t pgsize = sysconf(_SC_PAGESIZE);
+ void *arena_base;
+ ssize_t i;
+ u8 *vec;
+ int ret;
+
+ ret = libarena_get_arena_base(arena_get_globals_fd, &arena_base);
+ if (ret)
+ return ret;
+
+ if (!arena_base)
+ return -EINVAL;
+
+ vec = calloc(arena_all_pages, sizeof(*vec));
+ if (!vec)
+ return -ENOMEM;
+
+ if (mincore(arena_base, arena_all_pages * pgsize, vec) < 0) {
+ ret = -errno;
+ free(vec);
+ return ret;
+ }
+
+ *globals_pages = 0;
+ for (i = arena_all_pages - 1; i >= 0; i--) {
+ if (!(vec[i] & 0x1))
+ break;
+ *globals_pages += 1;
+ }
+
+ free(vec);
+ return 0;
+}
--- /dev/null
+// SPDX-License-Identifier: LGPL-2.1 OR BSD-2-Clause
+/* Copyright (c) 2026 Meta Platforms, Inc. and affiliates. */
+#include <libarena/common.h>
+
+const volatile u32 zero = 0;
+
+int arena_fls(__u64 word)
+{
+ if (!word)
+ return 0;
+
+ return 64 - __builtin_clzll(word);
+}
+
+SEC("syscall")
+__weak int arena_get_info(struct arena_get_info_args *args)
+{
+ args->arena_base = arena_base(&arena);
+
+ return 0;
+}
+
+SEC("syscall")
+__weak int arena_alloc_reserve(struct arena_alloc_reserve_args *args)
+{
+ return bpf_arena_reserve_pages(&arena, NULL, args->nr_pages);
+}
+
+char _license[] SEC("license") = "GPL";
projects / thirdparty / kernel / linux.git / commitdiff
