警告: モジュール 'stap_30d' が retpoline が有効なコンパイラーなしでビルドされ、Spectre v2 の軽減策に影響する可能性がある。

Issue

• カーネルを retpoline パッチのあるバージョンに更新した後、カーネルモジュールをコンパイルできなくなります。

~/arch/x86/Makefile:166: *** CONFIG_RETPOLINE=y, but not supported by the compiler. Compiler update recommended

• カーネルを retpoline パッチのあるバージョンに更新した後、SystemTap を使用できなくなります。

# stap -v -g test.stp --all-modules
Pass 1: parsed user script and 110 library script(s) using 220084virt/37620res/3092shr/34892data kb, in 150usr/50sys/202real ms.
WARNING: kbuild exited with status: 2
WARNING: kbuild exited with status: 2
WARNING: kbuild exited with status: 2
WARNING: kbuild exited with status: 2
WARNING: kbuild exited with status: 2
WARNING: kbuild exited with status: 2
WARNING: kbuild exited with status: 2
WARNING: kbuild exited with status: 2
WARNING: kbuild exited with status: 2
WARNING: kbuild exited with status: 2
WARNING: kbuild exited with status: 2
WARNING: kbuild exited with status: 2
WARNING: kbuild exited with status: 2
WARNING: kbuild exited with status: 2
Pass 2: analyzed script: 2 probe(s), 9 function(s), 4 embed(s), 0 global(s) using 257512virt/75932res/3976shr/72320data kb, in 1770usr/2090sys/3621real ms.
Pass 3: translated to C into "/tmp/staptXOI0g/stap_2f46bb3244dec16cdb8cccc7821af177_5130_src.c" using 257512virt/76264res/4308shr/72320data kb, in 1540usr/140sys/1682real ms.
/usr/src/kernels/3.10.0-327.65.1.el7.x86_64/arch/x86/Makefile:163: *** CONFIG_RETPOLINE=y, but not supported by the compiler. Toolchain update recommended..  Stop.
WARNING: kbuild exited with status: 2
Pass 4: compiled C into "stap_2f46bb3244dec16cdb8cccc7821af177_5130.ko" in 80usr/110sys/181real ms.
Pass 4: compilation failed.  [man error::pass4]
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