diff mbox series

[PATCHv5,bpf-next,06/13] libbpf: Add support for uprobe multi session attach

Message ID 20240929205717.3813648-7-jolsa@kernel.org (mailing list archive)
State New
Headers show
Series uprobe, bpf: Add session support | expand

Commit Message

Jiri Olsa Sept. 29, 2024, 8:57 p.m. UTC 
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 | 21 ++++++++++++++++++---
 tools/lib/bpf/libbpf.h |  4 +++-
 3 files changed, 22 insertions(+), 4 deletions(-)

Comments

Andrii Nakryiko Sept. 30, 2024, 9:36 p.m. UTC | #1 
On Sun, Sep 29, 2024 at 1:58 PM 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 | 21 ++++++++++++++++++---
>  tools/lib/bpf/libbpf.h |  4 +++-
>  3 files changed, 22 insertions(+), 4 deletions(-)
>

LGTM, though see the nit below

Acked-by: Andrii Nakryiko <andrii@kernel.org>

> 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 3587ed7ec359..563ff5e64269 100644
> --- a/tools/lib/bpf/libbpf.c
> +++ b/tools/lib/bpf/libbpf.c
> @@ -9410,8 +9410,10 @@ 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_multi),
>         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_multi),
>         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),
> @@ -11733,7 +11735,10 @@ static int attach_uprobe_multi(const struct bpf_program *prog, long cookie, stru
>                 ret = 0;
>                 break;
>         case 3:
> -               opts.retprobe = str_has_pfx(probe_type, "uretprobe.multi");
> +               if (str_has_pfx(probe_type, "uprobe.session"))
> +                       opts.session = true;
> +               else
> +                       opts.retprobe = str_has_pfx(probe_type, "uretprobe.multi");

nit: this is very non-uniform, can you please just do:

opts.session = str_has_pfx(probe_type, "uprobe.session");
opts.retprobe = str_has_pfx(probe_type, "uretprobe.multi");

There is no need to micro-optimize str_has_pfx() calls, IMO.

>                 *link = bpf_program__attach_uprobe_multi(prog, -1, binary_path, func_name, &opts);
>                 ret = libbpf_get_error(*link);
>                 break;

[...]
Jiri Olsa Oct. 1, 2024, 1:18 p.m. UTC | #2 
On Mon, Sep 30, 2024 at 02:36:35PM -0700, Andrii Nakryiko wrote:
> On Sun, Sep 29, 2024 at 1:58 PM 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 | 21 ++++++++++++++++++---
> >  tools/lib/bpf/libbpf.h |  4 +++-
> >  3 files changed, 22 insertions(+), 4 deletions(-)
> >
> 
> LGTM, though see the nit below
> 
> Acked-by: Andrii Nakryiko <andrii@kernel.org>
> 
> > 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 3587ed7ec359..563ff5e64269 100644
> > --- a/tools/lib/bpf/libbpf.c
> > +++ b/tools/lib/bpf/libbpf.c
> > @@ -9410,8 +9410,10 @@ 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_multi),
> >         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_multi),
> >         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),
> > @@ -11733,7 +11735,10 @@ static int attach_uprobe_multi(const struct bpf_program *prog, long cookie, stru
> >                 ret = 0;
> >                 break;
> >         case 3:
> > -               opts.retprobe = str_has_pfx(probe_type, "uretprobe.multi");
> > +               if (str_has_pfx(probe_type, "uprobe.session"))
> > +                       opts.session = true;
> > +               else
> > +                       opts.retprobe = str_has_pfx(probe_type, "uretprobe.multi");
> 
> nit: this is very non-uniform, can you please just do:
> 
> opts.session = str_has_pfx(probe_type, "uprobe.session");
> opts.retprobe = str_has_pfx(probe_type, "uretprobe.multi");
> 
> There is no need to micro-optimize str_has_pfx() calls, IMO.

sure, will change

thanks,
jirka
diff mbox series

Patch

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 3587ed7ec359..563ff5e64269 100644
--- a/tools/lib/bpf/libbpf.c
+++ b/tools/lib/bpf/libbpf.c
@@ -9410,8 +9410,10 @@  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_multi),
 	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_multi),
 	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),
@@ -11733,7 +11735,10 @@  static int attach_uprobe_multi(const struct bpf_program *prog, long cookie, stru
 		ret = 0;
 		break;
 	case 3:
-		opts.retprobe = str_has_pfx(probe_type, "uretprobe.multi");
+		if (str_has_pfx(probe_type, "uprobe.session"))
+			opts.session = true;
+		else
+			opts.retprobe = str_has_pfx(probe_type, "uretprobe.multi");
 		*link = bpf_program__attach_uprobe_multi(prog, -1, binary_path, func_name, &opts);
 		ret = libbpf_get_error(*link);
 		break;
@@ -11982,10 +11987,12 @@  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;
@@ -12056,12 +12063,20 @@  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();
@@ -12075,7 +12090,7 @@  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 91484303849c..b2ce3a72b11d 100644
--- a/tools/lib/bpf/libbpf.h
+++ b/tools/lib/bpf/libbpf.h
@@ -577,10 +577,12 @@  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