Commit fb355812 authored Nov 24, 2020 by Andrei Matei Committed by Daniel Borkmann Nov 26, 2020

bpf: Fix selftest compilation on clang 11

Before this patch, profiler.inc.h wouldn't compile with clang-11 (before
the __builtin_preserve_enum_value LLVM builtin was introduced in
https://reviews.llvm.org/D83242).

Another test that uses this builtin (test_core_enumval) is conditionally
skipped if the compiler is too old. In that spirit, this patch inhibits
part of populate_cgroup_info(), which needs this CO-RE builtin. The
selftests build again on clang-11.

The affected test (the profiler test) doesn't pass on clang-11 because
it's missing https://reviews.llvm.org/D85570

, but at least the test suite
as a whole compiles. The test's expected failure is already called out in
the README.

Signed-off-by: Andrei Matei <andreimatei1@gmail.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Tested-by: Florian Lehner <dev@der-flo.net>
Acked-by: Yonghong Song <yhs@fb.com>
Link: https://lore.kernel.org/bpf/20201125035255.17970-1-andreimatei1@gmail.com

parent 34b82d3a

tools/testing/selftests/bpf/progs/profiler.inc.h

+2 −0

Original line number	Diff line number	Diff line
		@@ -256,6 +256,7 @@ static INLINE void* populate_cgroup_info(struct cgroup_data_t* cgroup_data,
		BPF_CORE_READ(task, nsproxy, cgroup_ns, root_cset, dfl_cgrp, kn);
		struct kernfs_node* proc_kernfs = BPF_CORE_READ(task, cgroups, dfl_cgrp, kn);

		#if __has_builtin(__builtin_preserve_enum_value)
		if (ENABLE_CGROUP_V1_RESOLVER && CONFIG_CGROUP_PIDS) {
		int cgrp_id = bpf_core_enum_value(enum cgroup_subsys_id___local,
		pids_cgrp_id___local);
		@@ -275,6 +276,7 @@ static INLINE void* populate_cgroup_info(struct cgroup_data_t* cgroup_data,
		}
		}
		}
		#endif

		cgroup_data->cgroup_root_inode = get_inode_from_kernfs(root_kernfs);
		cgroup_data->cgroup_proc_inode = get_inode_from_kernfs(proc_kernfs);

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