selftests/bpf: Add missing trampoline program type to trampoline_count test

Currently the trampoline_count test doesn't include any fmod_ret bpf programs, fix it to make the test cover all possible trampoline program types. Since fmod_ret bpf programs can't be attached to __set_task_comm function, as it's neither whitelisted for error injection nor a security hook, change it to bpf_modify_return_test. This patch also does some other cleanups such as removing duplicate code, dropping inconsistent comments, etc.

Yuntao Wang committed 4 years ago

Commit b23316a1 parent 96af42c3 files · +61 −91Browse files

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include/linux/bpf.h+1−1

@@ -724,7 +724,7 @@ struct btf_func_model { · 723 unmodified lines
724	724	#define BPF_TRAMP_F_RET_FENTRY_RET BIT(4)
725	725
726	726	/* Each call __bpf_prog_enter + call bpf_func + call __bpf_prog_exit is ~50
727		− * bytes on x86. Pick a number to fit into BPF_IMAGE_SIZE / 2
	727	+ * bytes on x86.
728	728	*/
729	729	#define BPF_MAX_TRAMP_LINKS 38
730	730