From 36ffb2023e3703a64266ca5fed30f710b1263c70 Mon Sep 17 00:00:00 2001 From: Andrii Nakryiko Date: Tue, 19 Mar 2024 16:38:51 -0700 Subject: libbpf: add support for BPF cookie for raw_tp/tp_btf programs Wire up BPF cookie passing or raw_tp and tp_btf programs, both in low-level and high-level APIs. Acked-by: Stanislav Fomichev Acked-by: Eduard Zingerman Signed-off-by: Andrii Nakryiko Message-ID: <20240319233852.1977493-5-andrii@kernel.org> Signed-off-by: Alexei Starovoitov --- tools/lib/bpf/bpf.c | 16 ++++++++++++++-- 1 file changed, 14 insertions(+), 2 deletions(-) (limited to 'tools/lib/bpf/bpf.c') diff --git a/tools/lib/bpf/bpf.c b/tools/lib/bpf/bpf.c index 97ec005c3c47..c9f4e04f38fe 100644 --- a/tools/lib/bpf/bpf.c +++ b/tools/lib/bpf/bpf.c @@ -785,6 +785,7 @@ int bpf_link_create(int prog_fd, int target_fd, if (!OPTS_ZEROED(opts, uprobe_multi)) return libbpf_err(-EINVAL); break; + case BPF_TRACE_RAW_TP: case BPF_TRACE_FENTRY: case BPF_TRACE_FEXIT: case BPF_MODIFY_RETURN: @@ -1173,20 +1174,31 @@ int bpf_link_get_info_by_fd(int link_fd, struct bpf_link_info *info, __u32 *info return bpf_obj_get_info_by_fd(link_fd, info, info_len); } -int bpf_raw_tracepoint_open(const char *name, int prog_fd) +int bpf_raw_tracepoint_open_opts(int prog_fd, struct bpf_raw_tp_opts *opts) { const size_t attr_sz = offsetofend(union bpf_attr, raw_tracepoint); union bpf_attr attr; int fd; + if (!OPTS_VALID(opts, bpf_raw_tp_opts)) + return libbpf_err(-EINVAL); + memset(&attr, 0, attr_sz); - attr.raw_tracepoint.name = ptr_to_u64(name); attr.raw_tracepoint.prog_fd = prog_fd; + attr.raw_tracepoint.name = ptr_to_u64(OPTS_GET(opts, tp_name, NULL)); + attr.raw_tracepoint.cookie = OPTS_GET(opts, cookie, 0); fd = sys_bpf_fd(BPF_RAW_TRACEPOINT_OPEN, &attr, attr_sz); return libbpf_err_errno(fd); } +int bpf_raw_tracepoint_open(const char *name, int prog_fd) +{ + LIBBPF_OPTS(bpf_raw_tp_opts, opts, .tp_name = name); + + return bpf_raw_tracepoint_open_opts(prog_fd, &opts); +} + int bpf_btf_load(const void *btf_data, size_t btf_size, struct bpf_btf_load_opts *opts) { const size_t attr_sz = offsetofend(union bpf_attr, btf_token_fd); -- cgit v1.2.3-59-g8ed1b From 2ca178f02b2f4e523e970894def16282e4adbc39 Mon Sep 17 00:00:00 2001 From: Jiri Olsa Date: Tue, 30 Apr 2024 13:28:27 +0200 Subject: libbpf: Add support for kprobe session attach Adding support to attach program in kprobe session mode with bpf_program__attach_kprobe_multi_opts function. Adding session bool to bpf_kprobe_multi_opts struct that allows to load and attach the bpf program via kprobe session. the attachment to create kprobe multi session. Also adding new program loader section that allows: SEC("kprobe.session/bpf_fentry_test*") and loads/attaches kprobe program as kprobe session. Signed-off-by: Jiri Olsa Signed-off-by: Andrii Nakryiko Acked-by: Andrii Nakryiko Link: https://lore.kernel.org/bpf/20240430112830.1184228-5-jolsa@kernel.org --- tools/lib/bpf/bpf.c | 1 + tools/lib/bpf/libbpf.c | 39 +++++++++++++++++++++++++++++++++++++-- tools/lib/bpf/libbpf.h | 4 +++- 3 files changed, 41 insertions(+), 3 deletions(-) (limited to 'tools/lib/bpf/bpf.c') diff --git a/tools/lib/bpf/bpf.c b/tools/lib/bpf/bpf.c index c9f4e04f38fe..466a29d80124 100644 --- a/tools/lib/bpf/bpf.c +++ b/tools/lib/bpf/bpf.c @@ -766,6 +766,7 @@ int bpf_link_create(int prog_fd, int target_fd, return libbpf_err(-EINVAL); break; case BPF_TRACE_KPROBE_MULTI: + case BPF_TRACE_KPROBE_SESSION: attr.link_create.kprobe_multi.flags = OPTS_GET(opts, kprobe_multi.flags, 0); attr.link_create.kprobe_multi.cnt = OPTS_GET(opts, kprobe_multi.cnt, 0); attr.link_create.kprobe_multi.syms = ptr_to_u64(OPTS_GET(opts, kprobe_multi.syms, 0)); diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c index 898d5d34ecea..16dae279a900 100644 --- a/tools/lib/bpf/libbpf.c +++ b/tools/lib/bpf/libbpf.c @@ -9273,6 +9273,7 @@ static int attach_tp(const struct bpf_program *prog, long cookie, struct bpf_lin static int attach_raw_tp(const struct bpf_program *prog, long cookie, struct bpf_link **link); static int attach_trace(const struct bpf_program *prog, long cookie, struct bpf_link **link); static int attach_kprobe_multi(const struct bpf_program *prog, long cookie, struct bpf_link **link); +static int attach_kprobe_session(const struct bpf_program *prog, long cookie, struct bpf_link **link); static int attach_uprobe_multi(const struct bpf_program *prog, long cookie, struct bpf_link **link); static int attach_lsm(const struct bpf_program *prog, long cookie, struct bpf_link **link); static int attach_iter(const struct bpf_program *prog, long cookie, struct bpf_link **link); @@ -9289,6 +9290,7 @@ static const struct bpf_sec_def section_defs[] = { SEC_DEF("uretprobe.s+", KPROBE, 0, SEC_SLEEPABLE, attach_uprobe), SEC_DEF("kprobe.multi+", KPROBE, BPF_TRACE_KPROBE_MULTI, SEC_NONE, attach_kprobe_multi), SEC_DEF("kretprobe.multi+", KPROBE, BPF_TRACE_KPROBE_MULTI, SEC_NONE, attach_kprobe_multi), + SEC_DEF("kprobe.session+", KPROBE, BPF_TRACE_KPROBE_SESSION, SEC_NONE, attach_kprobe_session), SEC_DEF("uprobe.multi+", KPROBE, BPF_TRACE_UPROBE_MULTI, SEC_NONE, attach_uprobe_multi), SEC_DEF("uretprobe.multi+", KPROBE, BPF_TRACE_UPROBE_MULTI, SEC_NONE, attach_uprobe_multi), SEC_DEF("uprobe.multi.s+", KPROBE, BPF_TRACE_UPROBE_MULTI, SEC_SLEEPABLE, attach_uprobe_multi), @@ -11381,13 +11383,14 @@ bpf_program__attach_kprobe_multi_opts(const struct bpf_program *prog, struct kprobe_multi_resolve res = { .pattern = pattern, }; + enum bpf_attach_type attach_type; struct bpf_link *link = NULL; char errmsg[STRERR_BUFSIZE]; const unsigned long *addrs; int err, link_fd, prog_fd; + bool retprobe, session; const __u64 *cookies; const char **syms; - bool retprobe; size_t cnt; if (!OPTS_VALID(opts, bpf_kprobe_multi_opts)) @@ -11426,6 +11429,12 @@ bpf_program__attach_kprobe_multi_opts(const struct bpf_program *prog, } retprobe = OPTS_GET(opts, retprobe, false); + session = OPTS_GET(opts, session, false); + + if (retprobe && session) + return libbpf_err_ptr(-EINVAL); + + attach_type = session ? BPF_TRACE_KPROBE_SESSION : BPF_TRACE_KPROBE_MULTI; lopts.kprobe_multi.syms = syms; lopts.kprobe_multi.addrs = addrs; @@ -11440,7 +11449,7 @@ bpf_program__attach_kprobe_multi_opts(const struct bpf_program *prog, } link->detach = &bpf_link__detach_fd; - link_fd = bpf_link_create(prog_fd, 0, BPF_TRACE_KPROBE_MULTI, &lopts); + link_fd = bpf_link_create(prog_fd, 0, attach_type, &lopts); if (link_fd < 0) { err = -errno; pr_warn("prog '%s': failed to attach: %s\n", @@ -11546,6 +11555,32 @@ static int attach_kprobe_multi(const struct bpf_program *prog, long cookie, stru return libbpf_get_error(*link); } +static int attach_kprobe_session(const struct bpf_program *prog, long cookie, + struct bpf_link **link) +{ + LIBBPF_OPTS(bpf_kprobe_multi_opts, opts, .session = true); + const char *spec; + char *pattern; + int n; + + *link = NULL; + + /* no auto-attach for SEC("kprobe.session") */ + if (strcmp(prog->sec_name, "kprobe.session") == 0) + return 0; + + spec = prog->sec_name + sizeof("kprobe.session/") - 1; + n = sscanf(spec, "%m[a-zA-Z0-9_.*?]", &pattern); + if (n < 1) { + pr_warn("kprobe session pattern is invalid: %s\n", pattern); + return -EINVAL; + } + + *link = bpf_program__attach_kprobe_multi_opts(prog, pattern, &opts); + free(pattern); + return *link ? 0 : -errno; +} + static int attach_uprobe_multi(const struct bpf_program *prog, long cookie, struct bpf_link **link) { char *probe_type = NULL, *binary_path = NULL, *func_name = NULL; diff --git a/tools/lib/bpf/libbpf.h b/tools/lib/bpf/libbpf.h index 1333ae20ebe6..c3f77d9260fe 100644 --- a/tools/lib/bpf/libbpf.h +++ b/tools/lib/bpf/libbpf.h @@ -539,10 +539,12 @@ struct bpf_kprobe_multi_opts { size_t cnt; /* create return kprobes */ bool retprobe; + /* create session kprobes */ + bool session; size_t :0; }; -#define bpf_kprobe_multi_opts__last_field retprobe +#define bpf_kprobe_multi_opts__last_field session LIBBPF_API struct bpf_link * bpf_program__attach_kprobe_multi_opts(const struct bpf_program *prog, -- cgit v1.2.3-59-g8ed1b From 1de27bba6d50a909647f304eadc0f7c59a842a50 Mon Sep 17 00:00:00 2001 From: Andrii Nakryiko Date: Mon, 13 May 2024 11:08:03 -0700 Subject: libbpf: fix feature detectors when using token_fd Adjust `union bpf_attr` size passed to kernel in two feature-detecting functions to take into account prog_token_fd field. Libbpf is avoiding memset()'ing entire `union bpf_attr` by only using minimal set of bpf_attr's fields. Two places have been missed when wiring BPF token support in libbpf's feature detection logic. Fix them trivially. Fixes: f3dcee938f48 ("libbpf: Wire up token_fd into feature probing logic") Signed-off-by: Andrii Nakryiko Link: https://lore.kernel.org/r/20240513180804.403775-1-andrii@kernel.org Signed-off-by: Alexei Starovoitov --- tools/lib/bpf/bpf.c | 2 +- tools/lib/bpf/features.c | 2 +- 2 files changed, 2 insertions(+), 2 deletions(-) (limited to 'tools/lib/bpf/bpf.c') diff --git a/tools/lib/bpf/bpf.c b/tools/lib/bpf/bpf.c index 466a29d80124..2a4c71501a17 100644 --- a/tools/lib/bpf/bpf.c +++ b/tools/lib/bpf/bpf.c @@ -105,7 +105,7 @@ int sys_bpf_prog_load(union bpf_attr *attr, unsigned int size, int attempts) */ int probe_memcg_account(int token_fd) { - const size_t attr_sz = offsetofend(union bpf_attr, attach_btf_obj_fd); + const size_t attr_sz = offsetofend(union bpf_attr, prog_token_fd); struct bpf_insn insns[] = { BPF_EMIT_CALL(BPF_FUNC_ktime_get_coarse_ns), BPF_EXIT_INSN(), diff --git a/tools/lib/bpf/features.c b/tools/lib/bpf/features.c index 4e783cc7fc4b..a336786a22a3 100644 --- a/tools/lib/bpf/features.c +++ b/tools/lib/bpf/features.c @@ -22,7 +22,7 @@ int probe_fd(int fd) static int probe_kern_prog_name(int token_fd) { - const size_t attr_sz = offsetofend(union bpf_attr, prog_name); + const size_t attr_sz = offsetofend(union bpf_attr, prog_token_fd); struct bpf_insn insns[] = { BPF_MOV64_IMM(BPF_REG_0, 0), BPF_EXIT_INSN(), -- cgit v1.2.3-59-g8ed1b