Add a utility to check the Kernel version.

Signed-off-by: fruffy <[email protected]>

Author: fruffy

backends/ebpf/CMakeLists.txt

@@ -182,21 +182,8 @@ set (EBPF_ERRORS_SUITES
   "${P4C_SOURCE_DIR}/testdata/p4_16_ebpf_errors/*.p4"
   )
 
-# determine the kernel version
-execute_process(COMMAND uname -r
-  OUTPUT_VARIABLE P4C_EBPF_KERNEL_VER
-  OUTPUT_STRIP_TRAILING_WHITESPACE
-  RESULT_VARIABLE rc)
-message(STATUS "Detected kernel version: ${P4C_EBPF_KERNEL_VER}")
-# Check if the kernel version is new enough to support ebpf features
-set (MIN_KERNEL 4.15.0)
-string (REGEX MATCH "[0-9]+[^-]*" KERNEL_VER ${CMAKE_SYSTEM})
-if (${KERNEL_VER} VERSION_LESS ${MIN_KERNEL} )
-  MESSAGE(WARNING "Kernel version ${KERNEL_VER} too small, expected ${MIN_KERNEL}. Ignoring ebpf kernel tests...")
-  set (SUPPORTS_KERNEL False)
-else()
-  set (SUPPORTS_KERNEL True)
-endif()
+include(CheckLinuxKernel)
+check_minimum_kernel_version("4.15.0" SUPPORTS_KERNEL)
 
 # Check if we have the right llvm version
 set (MIN_LLVM 3.7.1)
@@ -212,14 +199,14 @@ if (NOT LLVM_RET)
   if (${LLVM_PACKAGE_VERSION} VERSION_LESS ${MIN_LLVM})
     message(WARNING "LLVM version ${LLVM_PACKAGE_VERSION} too small, expected ${MIN_LLVM}.
     Ignoring ebpf tests...")
-    set (SUPPORTS_KERNEL False)
+    set (SUPPORTS_KERNEL FALSE)
   endif()
 else()
   message(WARNING
     "Did not find an LLVM version that can compile the eBPF kernel tests...\n"
     "'llvm-config' reason: ${LLVM_PACKAGE_VERSION}\n"
     "'llvm-config' return value: ${LLVM_RET}" )
-  set (SUPPORTS_KERNEL False)
+  set (SUPPORTS_KERNEL FALSE)
 endif()
 
 # check for the libbpf library
@@ -230,7 +217,7 @@ else()
   message(WARNING "Missing the libbpf dependency, disabling kernel tests."
   " You can install libbpf by running './build_libbpf' in the "
   "${CMAKE_CURRENT_SOURCE_DIR} folder.")
-  set (SUPPORTS_KERNEL False)
+  set (SUPPORTS_KERNEL FALSE)
 endif()
 
 # Only add the kernel tests if the two requirements are met

backends/tc/CMakeLists.txt

@@ -133,9 +133,16 @@ macro(p4tc_add_test_with_args tag driver isXfail alias p4test test_args cmake_ar
     set_tests_properties(${__testname} PROPERTIES TIMEOUT 1000)
 endmacro(p4tc_add_test_with_args)
 
-p4c_add_tests("p4tc" ${P4TC_COMPILER_DRIVER} "${P4_16_SUITES}" "")
+include(CheckLinuxKernel)
+check_minimum_kernel_version("5.0.0" SUPPORTS_KERNEL)
 
 set(ENABLE_P4TC_STF_TESTS ON)
+
+if (SUPPORTS_KERNEL)
+    p4c_add_tests("p4tc" ${P4TC_COMPILER_DRIVER} "${P4_16_SUITES}" "")
+    set(ENABLE_P4TC_STF_TESTS OFF)
+endif()
+
 # brctl is required for the P4TC STF tests.
 find_program(BRCTL_EXEC brctl)
 # clang is required for the P4TC STF tests.