From 27d14b6e3b143634b05aeeeb752dfbdbccd6b658 Mon Sep 17 00:00:00 2001 From: Andrii Nakryiko Date: Mon, 13 Sep 2021 18:47:32 -0700 Subject: [PATCH] libbpf: Simplify BPF program auto-attach code Remove the need to explicitly pass bpf_sec_def for auto-attachable BPF programs, as it is already recorded at bpf_object__open() time for all recognized type of BPF programs. This further reduces number of explicit calls to find_sec_def(), simplifying further refactorings. No functional changes are done by this patch. Signed-off-by: Andrii Nakryiko Signed-off-by: Alexei Starovoitov Acked-by: Martin KaFai Lau Link: https://lore.kernel.org/bpf/20210914014733.2768-4-andrii@kernel.org --- src/libbpf.c | 61 +++++++++++++++++++--------------------------------- 1 file changed, 22 insertions(+), 39 deletions(-) diff --git a/src/libbpf.c b/src/libbpf.c index 6abfbf2..e473fbd 100644 --- a/src/libbpf.c +++ b/src/libbpf.c @@ -218,8 +218,7 @@ struct reloc_desc { struct bpf_sec_def; -typedef struct bpf_link *(*attach_fn_t)(const struct bpf_sec_def *sec, - struct bpf_program *prog); +typedef struct bpf_link *(*attach_fn_t)(struct bpf_program *prog); struct bpf_sec_def { const char *sec; @@ -7920,18 +7919,12 @@ void bpf_program__set_expected_attach_type(struct bpf_program *prog, __VA_ARGS__ \ } -static struct bpf_link *attach_kprobe(const struct bpf_sec_def *sec, - struct bpf_program *prog); -static struct bpf_link *attach_tp(const struct bpf_sec_def *sec, - struct bpf_program *prog); -static struct bpf_link *attach_raw_tp(const struct bpf_sec_def *sec, - struct bpf_program *prog); -static struct bpf_link *attach_trace(const struct bpf_sec_def *sec, - struct bpf_program *prog); -static struct bpf_link *attach_lsm(const struct bpf_sec_def *sec, - struct bpf_program *prog); -static struct bpf_link *attach_iter(const struct bpf_sec_def *sec, - struct bpf_program *prog); +static struct bpf_link *attach_kprobe(struct bpf_program *prog); +static struct bpf_link *attach_tp(struct bpf_program *prog); +static struct bpf_link *attach_raw_tp(struct bpf_program *prog); +static struct bpf_link *attach_trace(struct bpf_program *prog); +static struct bpf_link *attach_lsm(struct bpf_program *prog); +static struct bpf_link *attach_iter(struct bpf_program *prog); static const struct bpf_sec_def section_defs[] = { BPF_PROG_SEC("socket", BPF_PROG_TYPE_SOCKET_FILTER), @@ -9391,8 +9384,7 @@ struct bpf_link *bpf_program__attach_kprobe(struct bpf_program *prog, return bpf_program__attach_kprobe_opts(prog, func_name, &opts); } -static struct bpf_link *attach_kprobe(const struct bpf_sec_def *sec, - struct bpf_program *prog) +static struct bpf_link *attach_kprobe(struct bpf_program *prog) { DECLARE_LIBBPF_OPTS(bpf_kprobe_opts, opts); unsigned long offset = 0; @@ -9401,8 +9393,8 @@ static struct bpf_link *attach_kprobe(const struct bpf_sec_def *sec, char *func; int n, err; - func_name = prog->sec_name + sec->len; - opts.retprobe = strcmp(sec->sec, "kretprobe/") == 0; + func_name = prog->sec_name + prog->sec_def->len; + opts.retprobe = strcmp(prog->sec_def->sec, "kretprobe/") == 0; n = sscanf(func_name, "%m[a-zA-Z0-9_.]+%li", &func, &offset); if (n < 1) { @@ -9565,8 +9557,7 @@ struct bpf_link *bpf_program__attach_tracepoint(struct bpf_program *prog, return bpf_program__attach_tracepoint_opts(prog, tp_category, tp_name, NULL); } -static struct bpf_link *attach_tp(const struct bpf_sec_def *sec, - struct bpf_program *prog) +static struct bpf_link *attach_tp(struct bpf_program *prog) { char *sec_name, *tp_cat, *tp_name; struct bpf_link *link; @@ -9576,7 +9567,7 @@ static struct bpf_link *attach_tp(const struct bpf_sec_def *sec, return libbpf_err_ptr(-ENOMEM); /* extract "tp//" */ - tp_cat = sec_name + sec->len; + tp_cat = sec_name + prog->sec_def->len; tp_name = strchr(tp_cat, '/'); if (!tp_name) { free(sec_name); @@ -9620,10 +9611,9 @@ struct bpf_link *bpf_program__attach_raw_tracepoint(struct bpf_program *prog, return link; } -static struct bpf_link *attach_raw_tp(const struct bpf_sec_def *sec, - struct bpf_program *prog) +static struct bpf_link *attach_raw_tp(struct bpf_program *prog) { - const char *tp_name = prog->sec_name + sec->len; + const char *tp_name = prog->sec_name + prog->sec_def->len; return bpf_program__attach_raw_tracepoint(prog, tp_name); } @@ -9668,14 +9658,12 @@ struct bpf_link *bpf_program__attach_lsm(struct bpf_program *prog) return bpf_program__attach_btf_id(prog); } -static struct bpf_link *attach_trace(const struct bpf_sec_def *sec, - struct bpf_program *prog) +static struct bpf_link *attach_trace(struct bpf_program *prog) { return bpf_program__attach_trace(prog); } -static struct bpf_link *attach_lsm(const struct bpf_sec_def *sec, - struct bpf_program *prog) +static struct bpf_link *attach_lsm(struct bpf_program *prog) { return bpf_program__attach_lsm(prog); } @@ -9806,21 +9794,17 @@ bpf_program__attach_iter(struct bpf_program *prog, return link; } -static struct bpf_link *attach_iter(const struct bpf_sec_def *sec, - struct bpf_program *prog) +static struct bpf_link *attach_iter(struct bpf_program *prog) { return bpf_program__attach_iter(prog, NULL); } struct bpf_link *bpf_program__attach(struct bpf_program *prog) { - const struct bpf_sec_def *sec_def; - - sec_def = find_sec_def(prog->sec_name); - if (!sec_def || !sec_def->attach_fn) + if (!prog->sec_def || !prog->sec_def->attach_fn) return libbpf_err_ptr(-ESRCH); - return sec_def->attach_fn(sec_def, prog); + return prog->sec_def->attach_fn(prog); } static int bpf_link__detach_struct_ops(struct bpf_link *link) @@ -10899,16 +10883,15 @@ int bpf_object__attach_skeleton(struct bpf_object_skeleton *s) for (i = 0; i < s->prog_cnt; i++) { struct bpf_program *prog = *s->progs[i].prog; struct bpf_link **link = s->progs[i].link; - const struct bpf_sec_def *sec_def; if (!prog->load) continue; - sec_def = find_sec_def(prog->sec_name); - if (!sec_def || !sec_def->attach_fn) + /* auto-attaching not supported for this program */ + if (!prog->sec_def || !prog->sec_def->attach_fn) continue; - *link = sec_def->attach_fn(sec_def, prog); + *link = prog->sec_def->attach_fn(prog); err = libbpf_get_error(*link); if (err) { pr_warn("failed to auto-attach program '%s': %d\n",