| Message ID | 20240909074554.2339984-5-jolsa@kernel.org (mailing list archive) |
|---|---|
| State | Superseded |
| Headers | show |
| Series | uprobe, bpf: Add session support | expand |
On Mon, Sep 9, 2024 at 12:46 AM Jiri Olsa <jolsa@kernel.org> wrote: > > Adding support to attach program in uprobe session mode > with bpf_program__attach_uprobe_multi function. > > Adding session bool to bpf_uprobe_multi_opts struct that allows > to load and attach the bpf program via uprobe session. > the attachment to create uprobe multi session. > > Also adding new program loader section that allows: > SEC("uprobe.session/bpf_fentry_test*") > > and loads/attaches uprobe program as uprobe session. > > Adding sleepable hook (uprobe.session.s) as well. > > Signed-off-by: Jiri Olsa <jolsa@kernel.org> > --- > tools/lib/bpf/bpf.c | 1 + > tools/lib/bpf/libbpf.c | 50 ++++++++++++++++++++++++++++++++++++++++-- > tools/lib/bpf/libbpf.h | 4 +++- > 3 files changed, 52 insertions(+), 3 deletions(-) > [...] > +static int attach_uprobe_session(const struct bpf_program *prog, long cookie, struct bpf_link **link) > +{ > + LIBBPF_OPTS(bpf_uprobe_multi_opts, opts, .session = true); > + char *binary_path = NULL, *func_name = NULL; > + int n, ret = -EINVAL; > + const char *spec; > + > + *link = NULL; > + > + spec = prog->sec_name + sizeof("uprobe.session/") - 1; > + if (cookie & SEC_SLEEPABLE) > + spec += 2; /* extra '.s' */ > + n = sscanf(spec, "%m[^:]:%m[^\n]", &binary_path, &func_name); > + > + switch (n) { > + case 1: > + /* but auto-attach is impossible. */ > + ret = 0; > + break; > + case 2: > + *link = bpf_program__attach_uprobe_multi(prog, -1, binary_path, func_name, &opts); > + ret = *link ? 0 : -errno; > + break; > + default: > + pr_warn("prog '%s': invalid format of section definition '%s'\n", prog->name, > + prog->sec_name); > + break; > + } > + free(binary_path); > + free(func_name); > + return ret; > +} why adding this whole attach_uprobe_session if attach_uprobe_multi() is almost exactly what you need. We just need to teach attach_uprobe_multi to recognize uprobe.session prefix with strncmp(), no? The rest of the logic is exactly the same. BTW, maybe you can fix attach_uprobe_multi() while at it: opts.retprobe = strcmp(probe_type, "uretprobe.multi") == 0; that should be strncmp() to accommodate uretprobe.multi.s, no? Original author (wink-wink) didn't account for that ".s", it seems... (actually please send a small fix to bpf-next separately, so we can apply it sooner) > + > static void gen_uprobe_legacy_event_name(char *buf, size_t buf_sz, > const char *binary_path, uint64_t offset) > { > @@ -11933,10 +11969,12 @@ bpf_program__attach_uprobe_multi(const struct bpf_program *prog, > const unsigned long *ref_ctr_offsets = NULL, *offsets = NULL; > LIBBPF_OPTS(bpf_link_create_opts, lopts); > unsigned long *resolved_offsets = NULL; > + enum bpf_attach_type attach_type; > int err = 0, link_fd, prog_fd; > struct bpf_link *link = NULL; > char errmsg[STRERR_BUFSIZE]; > char full_path[PATH_MAX]; > + bool retprobe, session; > const __u64 *cookies; > const char **syms; > size_t cnt; [...]
On Mon, Sep 09, 2024 at 04:44:44PM -0700, Andrii Nakryiko wrote: > On Mon, Sep 9, 2024 at 12:46 AM Jiri Olsa <jolsa@kernel.org> wrote: > > > > Adding support to attach program in uprobe session mode > > with bpf_program__attach_uprobe_multi function. > > > > Adding session bool to bpf_uprobe_multi_opts struct that allows > > to load and attach the bpf program via uprobe session. > > the attachment to create uprobe multi session. > > > > Also adding new program loader section that allows: > > SEC("uprobe.session/bpf_fentry_test*") > > > > and loads/attaches uprobe program as uprobe session. > > > > Adding sleepable hook (uprobe.session.s) as well. > > > > Signed-off-by: Jiri Olsa <jolsa@kernel.org> > > --- > > tools/lib/bpf/bpf.c | 1 + > > tools/lib/bpf/libbpf.c | 50 ++++++++++++++++++++++++++++++++++++++++-- > > tools/lib/bpf/libbpf.h | 4 +++- > > 3 files changed, 52 insertions(+), 3 deletions(-) > > > > [...] > > > +static int attach_uprobe_session(const struct bpf_program *prog, long cookie, struct bpf_link **link) > > +{ > > + LIBBPF_OPTS(bpf_uprobe_multi_opts, opts, .session = true); > > + char *binary_path = NULL, *func_name = NULL; > > + int n, ret = -EINVAL; > > + const char *spec; > > + > > + *link = NULL; > > + > > + spec = prog->sec_name + sizeof("uprobe.session/") - 1; > > + if (cookie & SEC_SLEEPABLE) > > + spec += 2; /* extra '.s' */ > > + n = sscanf(spec, "%m[^:]:%m[^\n]", &binary_path, &func_name); > > + > > + switch (n) { > > + case 1: > > + /* but auto-attach is impossible. */ > > + ret = 0; > > + break; > > + case 2: > > + *link = bpf_program__attach_uprobe_multi(prog, -1, binary_path, func_name, &opts); > > + ret = *link ? 0 : -errno; > > + break; > > + default: > > + pr_warn("prog '%s': invalid format of section definition '%s'\n", prog->name, > > + prog->sec_name); > > + break; > > + } > > + free(binary_path); > > + free(func_name); > > + return ret; > > +} > > why adding this whole attach_uprobe_session if attach_uprobe_multi() > is almost exactly what you need. We just need to teach > attach_uprobe_multi to recognize uprobe.session prefix with strncmp(), > no? The rest of the logic is exactly the same. ok, that's better > > BTW, maybe you can fix attach_uprobe_multi() while at it: > > opts.retprobe = strcmp(probe_type, "uretprobe.multi") == 0; > > that should be strncmp() to accommodate uretprobe.multi.s, no? > Original author (wink-wink) didn't account for that ".s", it seems... > > (actually please send a small fix to bpf-next separately, so we can > apply it sooner) hum, right.. I wonder why the test is passing, will send a fix thanks, jirka > > > + > > static void gen_uprobe_legacy_event_name(char *buf, size_t buf_sz, > > const char *binary_path, uint64_t offset) > > { > > @@ -11933,10 +11969,12 @@ bpf_program__attach_uprobe_multi(const struct bpf_program *prog, > > const unsigned long *ref_ctr_offsets = NULL, *offsets = NULL; > > LIBBPF_OPTS(bpf_link_create_opts, lopts); > > unsigned long *resolved_offsets = NULL; > > + enum bpf_attach_type attach_type; > > int err = 0, link_fd, prog_fd; > > struct bpf_link *link = NULL; > > char errmsg[STRERR_BUFSIZE]; > > char full_path[PATH_MAX]; > > + bool retprobe, session; > > const __u64 *cookies; > > const char **syms; > > size_t cnt; > > [...]
diff --git a/tools/lib/bpf/bpf.c b/tools/lib/bpf/bpf.c index 2a4c71501a17..becdfa701c75 100644 --- a/tools/lib/bpf/bpf.c +++ b/tools/lib/bpf/bpf.c @@ -776,6 +776,7 @@ int bpf_link_create(int prog_fd, int target_fd, return libbpf_err(-EINVAL); break; case BPF_TRACE_UPROBE_MULTI: + case BPF_TRACE_UPROBE_SESSION: attr.link_create.uprobe_multi.flags = OPTS_GET(opts, uprobe_multi.flags, 0); attr.link_create.uprobe_multi.cnt = OPTS_GET(opts, uprobe_multi.cnt, 0); attr.link_create.uprobe_multi.path = ptr_to_u64(OPTS_GET(opts, uprobe_multi.path, 0)); diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c index 274441674f92..7b72a29b09a7 100644 --- a/tools/lib/bpf/libbpf.c +++ b/tools/lib/bpf/libbpf.c @@ -9345,6 +9345,7 @@ static int attach_trace(const struct bpf_program *prog, long cookie, struct bpf_ 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_uprobe_session(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); @@ -9363,8 +9364,10 @@ static const struct bpf_sec_def section_defs[] = { 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.session+", KPROBE, BPF_TRACE_UPROBE_SESSION, SEC_NONE, attach_uprobe_session), SEC_DEF("uprobe.multi.s+", KPROBE, BPF_TRACE_UPROBE_MULTI, SEC_SLEEPABLE, attach_uprobe_multi), SEC_DEF("uretprobe.multi.s+", KPROBE, BPF_TRACE_UPROBE_MULTI, SEC_SLEEPABLE, attach_uprobe_multi), + SEC_DEF("uprobe.session.s+", KPROBE, BPF_TRACE_UPROBE_SESSION, SEC_SLEEPABLE, attach_uprobe_session), SEC_DEF("ksyscall+", KPROBE, 0, SEC_NONE, attach_ksyscall), SEC_DEF("kretsyscall+", KPROBE, 0, SEC_NONE, attach_ksyscall), SEC_DEF("usdt+", KPROBE, 0, SEC_USDT, attach_usdt), @@ -11699,6 +11702,39 @@ static int attach_uprobe_multi(const struct bpf_program *prog, long cookie, stru return ret; } +static int attach_uprobe_session(const struct bpf_program *prog, long cookie, struct bpf_link **link) +{ + LIBBPF_OPTS(bpf_uprobe_multi_opts, opts, .session = true); + char *binary_path = NULL, *func_name = NULL; + int n, ret = -EINVAL; + const char *spec; + + *link = NULL; + + spec = prog->sec_name + sizeof("uprobe.session/") - 1; + if (cookie & SEC_SLEEPABLE) + spec += 2; /* extra '.s' */ + n = sscanf(spec, "%m[^:]:%m[^\n]", &binary_path, &func_name); + + switch (n) { + case 1: + /* but auto-attach is impossible. */ + ret = 0; + break; + case 2: + *link = bpf_program__attach_uprobe_multi(prog, -1, binary_path, func_name, &opts); + ret = *link ? 0 : -errno; + break; + default: + pr_warn("prog '%s': invalid format of section definition '%s'\n", prog->name, + prog->sec_name); + break; + } + free(binary_path); + free(func_name); + return ret; +} + static void gen_uprobe_legacy_event_name(char *buf, size_t buf_sz, const char *binary_path, uint64_t offset) { @@ -11933,10 +11969,12 @@ bpf_program__attach_uprobe_multi(const struct bpf_program *prog, const unsigned long *ref_ctr_offsets = NULL, *offsets = NULL; LIBBPF_OPTS(bpf_link_create_opts, lopts); unsigned long *resolved_offsets = NULL; + enum bpf_attach_type attach_type; int err = 0, link_fd, prog_fd; struct bpf_link *link = NULL; char errmsg[STRERR_BUFSIZE]; char full_path[PATH_MAX]; + bool retprobe, session; const __u64 *cookies; const char **syms; size_t cnt; @@ -12007,12 +12045,20 @@ bpf_program__attach_uprobe_multi(const struct bpf_program *prog, offsets = resolved_offsets; } + 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_UPROBE_SESSION : BPF_TRACE_UPROBE_MULTI; + lopts.uprobe_multi.path = path; lopts.uprobe_multi.offsets = offsets; lopts.uprobe_multi.ref_ctr_offsets = ref_ctr_offsets; lopts.uprobe_multi.cookies = cookies; lopts.uprobe_multi.cnt = cnt; - lopts.uprobe_multi.flags = OPTS_GET(opts, retprobe, false) ? BPF_F_UPROBE_MULTI_RETURN : 0; + lopts.uprobe_multi.flags = retprobe ? BPF_F_UPROBE_MULTI_RETURN : 0; if (pid == 0) pid = getpid(); @@ -12026,7 +12072,7 @@ bpf_program__attach_uprobe_multi(const struct bpf_program *prog, } link->detach = &bpf_link__detach_fd; - link_fd = bpf_link_create(prog_fd, 0, BPF_TRACE_UPROBE_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 multi-uprobe: %s\n", diff --git a/tools/lib/bpf/libbpf.h b/tools/lib/bpf/libbpf.h index 64a6a3d323e3..f6a7835dc519 100644 --- a/tools/lib/bpf/libbpf.h +++ b/tools/lib/bpf/libbpf.h @@ -569,10 +569,12 @@ struct bpf_uprobe_multi_opts { size_t cnt; /* create return uprobes */ bool retprobe; + /* create session kprobes */ + bool session; size_t :0; }; -#define bpf_uprobe_multi_opts__last_field retprobe +#define bpf_uprobe_multi_opts__last_field session /** * @brief **bpf_program__attach_uprobe_multi()** attaches a BPF program
Adding support to attach program in uprobe session mode with bpf_program__attach_uprobe_multi function. Adding session bool to bpf_uprobe_multi_opts struct that allows to load and attach the bpf program via uprobe session. the attachment to create uprobe multi session. Also adding new program loader section that allows: SEC("uprobe.session/bpf_fentry_test*") and loads/attaches uprobe program as uprobe session. Adding sleepable hook (uprobe.session.s) as well. Signed-off-by: Jiri Olsa <jolsa@kernel.org> --- tools/lib/bpf/bpf.c | 1 + tools/lib/bpf/libbpf.c | 50 ++++++++++++++++++++++++++++++++++++++++-- tools/lib/bpf/libbpf.h | 4 +++- 3 files changed, 52 insertions(+), 3 deletions(-)