use linux bpf uapi header from libbpf submodule

The uapi header
  src/cc/libbpf/include/uapi/linux/bpf.h
is used instead of the current way
  src/cc/compat/linux/bpf.h
Signed-off-by: Yonghong Song <yhs@fb.com>

examples/cpp/CMakeLists.txt

@@ -3,6 +3,7 @@
 
 include_directories(${CMAKE_SOURCE_DIR}/src/cc)
 include_directories(${CMAKE_SOURCE_DIR}/src/cc/api)
+include_directories(${CMAKE_SOURCE_DIR}/src/cc/libbpf/include/uapi)
 
 option(INSTALL_CPP_EXAMPLES "Install C++ examples. Those binaries are statically linked and can take plenty of disk space" OFF)
 

introspection/CMakeLists.txt

@@ -3,6 +3,7 @@
 
 include_directories(${CMAKE_SOURCE_DIR}/src/cc)
 include_directories(${CMAKE_SOURCE_DIR}/src/cc/api)
+include_directories(${CMAKE_SOURCE_DIR}/src/cc/libbpf/include/uapi)
 
 option(INSTALL_INTROSPECTION "Install BPF introspection tools" ON)
 

src/cc/CMakeLists.txt

@@ -10,7 +10,7 @@ include_directories(${CMAKE_CURRENT_SOURCE_DIR}/frontends/clang)
 include_directories(${LLVM_INCLUDE_DIRS})
 include_directories(${LIBELF_INCLUDE_DIRS})
 # todo: if check for kernel version
-include_directories(${CMAKE_CURRENT_SOURCE_DIR}/compat)
+include_directories(${CMAKE_CURRENT_SOURCE_DIR}/libbpf/include/uapi)
 add_definitions(${LLVM_DEFINITIONS})
 configure_file(libbcc.pc.in ${CMAKE_CURRENT_BINARY_DIR}/libbcc.pc @ONLY)
 
@@ -105,7 +105,7 @@ set(bcc-lua-static ${bcc-lua-static} ${bcc_common_libs_for_lua})
 install(TARGETS bcc-shared LIBRARY DESTINATION ${CMAKE_INSTALL_LIBDIR})
 install(FILES ${bcc_table_headers} DESTINATION include/bcc)
 install(FILES ${bcc_api_headers} DESTINATION include/bcc)
-install(DIRECTORY compat/linux/ DESTINATION include/bcc/compat/linux FILES_MATCHING PATTERN "*.h")
+install(DIRECTORY libbpf/include/uapi/linux/ DESTINATION include/bcc/compat/linux FILES_MATCHING PATTERN "*.h")
 install(FILES ${CMAKE_CURRENT_BINARY_DIR}/libbcc.pc DESTINATION ${CMAKE_INSTALL_LIBDIR}/pkgconfig)
 endif(ENABLE_CLANG_JIT)
 install(FILES ${bcc_common_headers} DESTINATION include/bcc)

src/cc/README

+The libbpf directory is a git submodule for repository
+  https://github.com/libbpf/libbpf
+
+If you have any change in libbpf directory, please upstream to linux
+first as libbpf repo is a mirror of linux/tools/lib/bpf directory.
+
+If any top-commit update of libbpf submodule contains a uapi header
+change, the following are necessary steps to sync properly with
+rest of bcc:
+  1. sync compat/linux/virtual_bpf.h with libbpf/include/uapi/linux/bpf.h
+     as virtual_bpf.h has an extra string wrapper for bpf.h.
+  2. if new bpf.h has new helpers, add corresponding helper func define
+     in bcc:src/cc/export/helpers.h and helper entry for error reporting
+     in bcc:src/cc/libbpf.c.
+  3. if new bpf.h has new map types, program types, update
+     bcc:introspection/bps.c for these new map/program types.

src/cc/api/BPF.h

@@ -26,7 +26,7 @@
 #include "bcc_exception.h"
 #include "bcc_syms.h"
 #include "bpf_module.h"
-#include "compat/linux/bpf.h"
+#include "linux/bpf.h"
 #include "libbpf.h"
 #include "table_storage.h"
 

src/cc/bcc_syms.h

@@ -21,7 +21,7 @@ extern "C" {
 #endif
 
 #include <stdint.h>
-#include "compat/linux/bpf.h"
+#include "linux/bpf.h"
 
 struct bcc_symbol {
   const char *name;

src/cc/compat/linux/bpf_common.h

-/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
-#ifndef _UAPI__LINUX_BPF_COMMON_H__
-#define _UAPI__LINUX_BPF_COMMON_H__
-
-/* Instruction classes */
-#define BPF_CLASS(code) ((code) & 0x07)
-#define		BPF_LD		0x00
-#define		BPF_LDX		0x01
-#define		BPF_ST		0x02
-#define		BPF_STX		0x03
-#define		BPF_ALU		0x04
-#define		BPF_JMP		0x05
-#define		BPF_RET		0x06
-#define		BPF_MISC        0x07
-
-/* ld/ldx fields */
-#define BPF_SIZE(code)  ((code) & 0x18)
-#define		BPF_W		0x00 /* 32-bit */
-#define		BPF_H		0x08 /* 16-bit */
-#define		BPF_B		0x10 /*  8-bit */
-/* eBPF		BPF_DW		0x18    64-bit */
-#define BPF_MODE(code)  ((code) & 0xe0)
-#define		BPF_IMM		0x00
-#define		BPF_ABS		0x20
-#define		BPF_IND		0x40
-#define		BPF_MEM		0x60
-#define		BPF_LEN		0x80
-#define		BPF_MSH		0xa0
-
-/* alu/jmp fields */
-#define BPF_OP(code)    ((code) & 0xf0)
-#define		BPF_ADD		0x00
-#define		BPF_SUB		0x10
-#define		BPF_MUL		0x20
-#define		BPF_DIV		0x30
-#define		BPF_OR		0x40
-#define		BPF_AND		0x50
-#define		BPF_LSH		0x60
-#define		BPF_RSH		0x70
-#define		BPF_NEG		0x80
-#define		BPF_MOD		0x90
-#define		BPF_XOR		0xa0
-
-#define		BPF_JA		0x00
-#define		BPF_JEQ		0x10
-#define		BPF_JGT		0x20
-#define		BPF_JGE		0x30
-#define		BPF_JSET        0x40
-#define BPF_SRC(code)   ((code) & 0x08)
-#define		BPF_K		0x00
-#define		BPF_X		0x08
-
-#ifndef BPF_MAXINSNS
-#define BPF_MAXINSNS 4096
-#endif
-
-#endif /* _UAPI__LINUX_BPF_COMMON_H__ */

src/cc/libbpf.h

@@ -18,7 +18,7 @@
 #ifndef LIBBPF_H
 #define LIBBPF_H
 
-#include "compat/linux/bpf.h"
+#include "linux/bpf.h"
 #include <stdint.h>
 #include <sys/types.h>
 

src/cc/shared_table.cc

@@ -18,7 +18,7 @@
 #include <iostream>
 
 #include "common.h"
-#include "compat/linux/bpf.h"
+#include "linux/bpf.h"
 #include "table_storage.h"
 #include "table_storage_impl.h"
 

tests/cc/CMakeLists.txt

@@ -3,6 +3,7 @@
 
 include_directories(${CMAKE_SOURCE_DIR}/src/cc)
 include_directories(${CMAKE_SOURCE_DIR}/src/cc/api)
+include_directories(${CMAKE_SOURCE_DIR}/src/cc/libbpf/include/uapi)
 
 add_executable(test_static test_static.c)
 target_link_libraries(test_static bcc-static)