kernel/bpf/core.o: warning: objtool: ___bpf_prog_run.cold()+0x7: call without frame pointer save/setup

From: He Zhe
Date: Mon Aug 26 2019 - 10:47:15 EST


Hi All,

Since 3193c0836f20 ("bpf: Disable GCC -fgcse optimization for ___bpf_prog_run()"),
We have got the following warning,
kernel/bpf/core.o: warning: objtool: ___bpf_prog_run.cold()+0x7: call without frame pointer save/setup

If reverting the above commit, we will get the following warning,
kernel/bpf/core.o: warning: objtool: ___bpf_prog_run()+0x8b9: sibling call from callable instruction with modified stack frame
if CONFIG_RETPOLINE=n, and no warning if CONFIG_RETPOLINE=y


Zhe