diff options
Diffstat (limited to 'common/native/bpf_headers/include/bpf/bpf_map_def.h')
| -rw-r--r-- | common/native/bpf_headers/include/bpf/bpf_map_def.h | 245 |
1 files changed, 0 insertions, 245 deletions
diff --git a/common/native/bpf_headers/include/bpf/bpf_map_def.h b/common/native/bpf_headers/include/bpf/bpf_map_def.h deleted file mode 100644 index e7428b6d..00000000 --- a/common/native/bpf_headers/include/bpf/bpf_map_def.h +++ /dev/null @@ -1,245 +0,0 @@ -/* - * Copyright (C) 2020 The Android Open Source Project - * - * Licensed under the Apache License, Version 2.0 (the "License"); - * you may not use this file except in compliance with the License. - * You may obtain a copy of the License at - * - * http://www.apache.org/licenses/LICENSE-2.0 - * - * Unless required by applicable law or agreed to in writing, software - * distributed under the License is distributed on an "AS IS" BASIS, - * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. - * See the License for the specific language governing permissions and - * limitations under the License. - */ - -#pragma once - -/* This file is separate because it's included both by eBPF programs (via include - * in bpf_helpers.h) and directly by the boot time bpfloader (Loader.cpp). - */ - -#include <linux/bpf.h> - -// Pull in AID_* constants from //system/core/libcutils/include/private/android_filesystem_config.h -#include <cutils/android_filesystem_config.h> - -/****************************************************************************** - * * - * ! ! ! W A R N I N G ! ! ! * - * * - * CHANGES TO THESE STRUCTURE DEFINITIONS OUTSIDE OF AOSP/MASTER *WILL* BREAK * - * MAINLINE MODULE COMPATIBILITY * - * * - * AND THUS MAY RESULT IN YOUR DEVICE BRICKING AT SOME ARBITRARY POINT IN * - * THE FUTURE * - * * - * (and even in aosp/master you may only append new fields at the very end, * - * you may *never* delete fields, change their types, ordering, insert in * - * the middle, etc. If a mainline module using the old definition has * - * already shipped (which happens roughly monthly), then it's set in stone) * - * * - ******************************************************************************/ - -// These are the values used if these fields are missing -#define DEFAULT_BPFLOADER_MIN_VER 0u // v0.0 (this is inclusive ie. >= v0.0) -#define DEFAULT_BPFLOADER_MAX_VER 0x10000u // v1.0 (this is exclusive ie. < v1.0) -#define DEFAULT_SIZEOF_BPF_MAP_DEF 32 // v0.0 struct: enum (uint sized) + 7 uint -#define DEFAULT_SIZEOF_BPF_PROG_DEF 20 // v0.0 struct: 4 uint + bool + 3 byte alignment pad - -// By default, unless otherwise specified, allow the use of features only supported by v0.37. -#define COMPILE_FOR_BPFLOADER_VERSION 37u - -/* - * The bpf_{map,prog}_def structures are compiled for different architectures. - * Once by the BPF compiler for the BPF architecture, and once by a C++ - * compiler for the native Android architecture for the bpfloader. - * - * For things to work, their layout must be the same between the two. - * The BPF architecture is platform independent ('64-bit LSB bpf'). - * So this effectively means these structures must be the same layout - * on 5 architectures, all of them little endian: - * 64-bit BPF, x86_64, arm and 32-bit x86 and arm - * - * As such for any types we use inside of these structs we must make sure that - * the size and alignment are the same, so the same amount of padding is used. - * - * Currently we only use: bool, enum bpf_map_type and unsigned int. - * Additionally we use char for padding. - * - * !!! WARNING: HERE BE DRAGONS !!! - * - * Be particularly careful with 64-bit integers. - * You will need to manually override their alignment to 8 bytes. - * - * To quote some parts of https://gcc.gnu.org/bugzilla/show_bug.cgi?id=69560 - * - * Some types have weaker alignment requirements when they are structure members. - * - * unsigned long long on x86 is such a type. - * - * C distinguishes C11 _Alignof (the minimum alignment the type is guaranteed - * to have in all contexts, so 4, see min_align_of_type) from GNU C __alignof - * (the normal alignment of the type, so 8). - * - * alignof / _Alignof == minimum alignment required by target ABI - * __alignof / __alignof__ == preferred alignment - * - * When in a struct, apparently the minimum alignment is used. - */ - -_Static_assert(sizeof(bool) == 1, "sizeof bool != 1"); -_Static_assert(__alignof__(bool) == 1, "__alignof__ bool != 1"); -_Static_assert(_Alignof(bool) == 1, "_Alignof bool != 1"); - -_Static_assert(sizeof(char) == 1, "sizeof char != 1"); -_Static_assert(__alignof__(char) == 1, "__alignof__ char != 1"); -_Static_assert(_Alignof(char) == 1, "_Alignof char != 1"); - -// This basically verifies that an enum is 'just' a 32-bit int -_Static_assert(sizeof(enum bpf_map_type) == 4, "sizeof enum bpf_map_type != 4"); -_Static_assert(__alignof__(enum bpf_map_type) == 4, "__alignof__ enum bpf_map_type != 4"); -_Static_assert(_Alignof(enum bpf_map_type) == 4, "_Alignof enum bpf_map_type != 4"); - -// Linux kernel requires sizeof(int) == 4, sizeof(void*) == sizeof(long), sizeof(long long) == 8 -_Static_assert(sizeof(unsigned int) == 4, "sizeof unsigned int != 4"); -_Static_assert(__alignof__(unsigned int) == 4, "__alignof__ unsigned int != 4"); -_Static_assert(_Alignof(unsigned int) == 4, "_Alignof unsigned int != 4"); - -// We don't currently use any 64-bit types in these structs, so this is purely to document issue. -// Here sizeof & __alignof__ are consistent, but _Alignof is not: compile for 'aosp_cf_x86_phone' -_Static_assert(sizeof(unsigned long long) == 8, "sizeof unsigned long long != 8"); -_Static_assert(__alignof__(unsigned long long) == 8, "__alignof__ unsigned long long != 8"); -// BPF wants 8, but 32-bit x86 wants 4 -//_Static_assert(_Alignof(unsigned long long) == 8, "_Alignof unsigned long long != 8"); - -// Length of strings (incl. selinux_context and pin_subdir) -// in the bpf_map_def and bpf_prog_def structs. -// -// WARNING: YOU CANNOT *EVER* CHANGE THESE -// as this would affect the structure size in backwards incompatible ways -// and break mainline module loading on older Android T devices -#define BPF_SELINUX_CONTEXT_CHAR_ARRAY_SIZE 32 -#define BPF_PIN_SUBDIR_CHAR_ARRAY_SIZE 32 - -/* - * Map structure to be used by Android eBPF C programs. The Android eBPF loader - * uses this structure from eBPF object to create maps at boot time. - * - * The eBPF C program should define structure in the maps section using - * SECTION("maps") otherwise it will be ignored by the eBPF loader. - * - * For example: - * const struct bpf_map_def SECTION("maps") mymap { .type=... , .key_size=... } - * - * See 'bpf_helpers.h' for helpful macros for eBPF program use. - */ -struct bpf_map_def { - enum bpf_map_type type; - unsigned int key_size; - unsigned int value_size; - unsigned int max_entries; - unsigned int map_flags; - - // The following are not supported by the Android bpfloader: - // unsigned int inner_map_idx; - // unsigned int numa_node; - - unsigned int zero; // uid_t, for compat with old (buggy) bpfloader must be AID_ROOT == 0 - unsigned int gid; // gid_t - unsigned int mode; // mode_t - - // The following fields were added in version 0.1 - unsigned int bpfloader_min_ver; // if missing, defaults to 0, ie. v0.0 - unsigned int bpfloader_max_ver; // if missing, defaults to 0x10000, ie. v1.0 - - // The following fields were added in version 0.2 (S) - // kernelVersion() must be >= min_kver and < max_kver - unsigned int min_kver; - unsigned int max_kver; - - // The following fields were added in version 0.18 (T) - // - // These are fixed length strings, padded with null bytes - // - // Warning: supported values depend on .o location - // (additionally a newer Android OS and/or bpfloader may support more values) - // - // overrides default selinux context (which is based on pin subdir) - char selinux_context[BPF_SELINUX_CONTEXT_CHAR_ARRAY_SIZE]; - // - // overrides default prefix (which is based on .o location) - char pin_subdir[BPF_PIN_SUBDIR_CHAR_ARRAY_SIZE]; - - bool shared; // use empty string as 'file' component of pin path - allows cross .o map sharing - - // The following 3 ignore_on_* fields were added in version 0.32 (U). These are ignored in - // older bpfloader versions, and zero in programs compiled before 0.32. - bool ignore_on_eng:1; - bool ignore_on_user:1; - bool ignore_on_userdebug:1; - // The following 5 ignore_on_* fields were added in version 0.38 (U). These are ignored in - // older bpfloader versions, and zero in programs compiled before 0.38. - // These are tests on the kernel architecture, ie. they ignore userspace bit-ness. - bool ignore_on_arm32:1; - bool ignore_on_aarch64:1; - bool ignore_on_x86_32:1; - bool ignore_on_x86_64:1; - bool ignore_on_riscv64:1; - - char pad0[2]; // manually pad up to 4 byte alignment, may be used for extensions in the future - - unsigned int uid; // uid_t -}; - -_Static_assert(sizeof(((struct bpf_map_def *)0)->selinux_context) == 32, "must be 32 bytes"); -_Static_assert(sizeof(((struct bpf_map_def *)0)->pin_subdir) == 32, "must be 32 bytes"); - -// This needs to be updated whenever the above structure definition is expanded. -_Static_assert(sizeof(struct bpf_map_def) == 120, "sizeof struct bpf_map_def != 120"); -_Static_assert(__alignof__(struct bpf_map_def) == 4, "__alignof__ struct bpf_map_def != 4"); -_Static_assert(_Alignof(struct bpf_map_def) == 4, "_Alignof struct bpf_map_def != 4"); - -struct bpf_prog_def { - unsigned int uid; - unsigned int gid; - - // kernelVersion() must be >= min_kver and < max_kver - unsigned int min_kver; - unsigned int max_kver; - - bool optional; // program section (ie. function) may fail to load, continue onto next func. - - // The following 3 ignore_on_* fields were added in version 0.33 (U). These are ignored in - // older bpfloader versions, and zero in programs compiled before 0.33. - bool ignore_on_eng:1; - bool ignore_on_user:1; - bool ignore_on_userdebug:1; - // The following 5 ignore_on_* fields were added in version 0.38 (U). These are ignored in - // older bpfloader versions, and zero in programs compiled before 0.38. - // These are tests on the kernel architecture, ie. they ignore userspace bit-ness. - bool ignore_on_arm32:1; - bool ignore_on_aarch64:1; - bool ignore_on_x86_32:1; - bool ignore_on_x86_64:1; - bool ignore_on_riscv64:1; - - char pad0[2]; // manually pad up to 4 byte alignment, may be used for extensions in the future - - // The following fields were added in version 0.1 - unsigned int bpfloader_min_ver; // if missing, defaults to 0, ie. v0.0 - unsigned int bpfloader_max_ver; // if missing, defaults to 0x10000, ie. v1.0 - - // The following fields were added in version 0.18, see description up above in bpf_map_def - char selinux_context[BPF_SELINUX_CONTEXT_CHAR_ARRAY_SIZE]; - char pin_subdir[BPF_PIN_SUBDIR_CHAR_ARRAY_SIZE]; -}; - -_Static_assert(sizeof(((struct bpf_prog_def *)0)->selinux_context) == 32, "must be 32 bytes"); -_Static_assert(sizeof(((struct bpf_prog_def *)0)->pin_subdir) == 32, "must be 32 bytes"); - -// This needs to be updated whenever the above structure definition is expanded. -_Static_assert(sizeof(struct bpf_prog_def) == 92, "sizeof struct bpf_prog_def != 92"); -_Static_assert(__alignof__(struct bpf_prog_def) == 4, "__alignof__ struct bpf_prog_def != 4"); -_Static_assert(_Alignof(struct bpf_prog_def) == 4, "_Alignof struct bpf_prog_def != 4"); |