Commit 2b288740 authored by Alexei Starovoitov's avatar Alexei Starovoitov Committed by Daniel Borkmann
Browse files

libbpf: Support sleepable progs 



Pass request to load program as sleepable via ".s" suffix in the section name.
If it happens in the future that all map types and helpers are allowed with
BPF_F_SLEEPABLE flag "fmod_ret/" and "lsm/" can be aliased to "fmod_ret.s/" and
"lsm.s/" to make all lsm and fmod_ret programs sleepable by default. The fentry
and fexit programs would always need to have sleepable vs non-sleepable
distinction, since not all fentry/fexit progs will be attached to sleepable
kernel functions.

Signed-off-by: default avatarAlexei Starovoitov <ast@kernel.org>
Signed-off-by: default avatarDaniel Borkmann <daniel@iogearbox.net>
Acked-by: default avatarKP Singh <kpsingh@google.com>
Acked-by: default avatarAndrii Nakryiko <andriin@fb.com>
Link: https://lore.kernel.org/bpf/20200827220114.69225-5-alexei.starovoitov@gmail.com
parent 07be4c4a

tools/lib/bpf/libbpf.c

+24 −1
Original line number Diff line number Diff line
@@ -208,6 +208,7 @@ struct bpf_sec_def { 
	bool is_exp_attach_type_optional;

	bool is_attachable;

	bool is_attach_btf;

	bool is_sleepable;

	attach_fn_t attach_fn;

};
@@ -6291,6 +6292,8 @@ __bpf_object__open(const char *path, const void *obj_buf, size_t obj_buf_sz, 
			/* couldn't guess, but user might manually specify */

			continue;



		if (prog->sec_def->is_sleepable)

			prog->prog_flags |= BPF_F_SLEEPABLE;

		bpf_program__set_type(prog, prog->sec_def->prog_type);

		bpf_program__set_expected_attach_type(prog,

				prog->sec_def->expected_attach_type);
@@ -7559,6 +7562,21 @@ static const struct bpf_sec_def section_defs[] = { 
		.expected_attach_type = BPF_TRACE_FEXIT,

		.is_attach_btf = true,

		.attach_fn = attach_trace),

	SEC_DEF("fentry.s/", TRACING,

		.expected_attach_type = BPF_TRACE_FENTRY,

		.is_attach_btf = true,

		.is_sleepable = true,

		.attach_fn = attach_trace),

	SEC_DEF("fmod_ret.s/", TRACING,

		.expected_attach_type = BPF_MODIFY_RETURN,

		.is_attach_btf = true,

		.is_sleepable = true,

		.attach_fn = attach_trace),

	SEC_DEF("fexit.s/", TRACING,

		.expected_attach_type = BPF_TRACE_FEXIT,

		.is_attach_btf = true,

		.is_sleepable = true,

		.attach_fn = attach_trace),

	SEC_DEF("freplace/", EXT,

		.is_attach_btf = true,

		.attach_fn = attach_trace),
@@ -7566,6 +7584,11 @@ static const struct bpf_sec_def section_defs[] = { 
		.is_attach_btf = true,

		.expected_attach_type = BPF_LSM_MAC,

		.attach_fn = attach_lsm),

	SEC_DEF("lsm.s/", LSM,

		.is_attach_btf = true,

		.is_sleepable = true,

		.expected_attach_type = BPF_LSM_MAC,

		.attach_fn = attach_lsm),

	SEC_DEF("iter/", TRACING,

		.expected_attach_type = BPF_TRACE_ITER,

		.is_attach_btf = true,
@@ -8288,7 +8311,7 @@ int bpf_prog_load_xattr(const struct bpf_prog_load_attr *attr, 


		prog->prog_ifindex = attr->ifindex;

		prog->log_level = attr->log_level;

		prog->prog_flags = attr->prog_flags;

		prog->prog_flags |= attr->prog_flags;

		if (!first_prog)

			first_prog = prog;

	}

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