Commit 06087114 authored by Daniel Borkmann's avatar Daniel Borkmann
Browse files

Merge branch 'bpf-cleanup-btf-raw-tp' 



Alexei Starovoitov says:

====================
v1->v2: addressed Andrii's feedback

When BTF-enabled raw_tp were introduced the plan was to follow up
with BTF-enabled kprobe and kretprobe reusing PROG_RAW_TRACEPOINT
and PROG_KPROBE types. But k[ret]probe expect pt_regs while
BTF-enabled program ctx will be the same as raw_tp.
kretprobe is indistinguishable from kprobe while BTF-enabled
kretprobe will have access to retval while kprobe will not.
Hence PROG_KPROBE type is not reusable and reusing
PROG_RAW_TRACEPOINT no longer fits well.
Hence introduce 'umbrella' prog type BPF_PROG_TYPE_TRACING
that will cover different BTF-enabled tracing attach points.
The changes make libbpf side cleaner as well.
check_attach_btf_id() is cleaner too.
====================

Signed-off-by: default avatarDaniel Borkmann <daniel@iogearbox.net>
parents af91acbc 12a8654b

include/linux/bpf.h

+5 −0
Original line number Diff line number Diff line
@@ -373,6 +373,11 @@ enum bpf_cgroup_storage_type { 


#define MAX_BPF_CGROUP_STORAGE_TYPE __BPF_CGROUP_STORAGE_MAX



/* The longest tracepoint has 12 args.

 * See include/trace/bpf_probe.h

 */

#define MAX_BPF_FUNC_ARGS 12



struct bpf_prog_stats {

	u64 cnt;

	u64 nsecs;

include/linux/bpf_types.h

+1 −0
Original line number Diff line number Diff line
@@ -26,6 +26,7 @@ BPF_PROG_TYPE(BPF_PROG_TYPE_TRACEPOINT, tracepoint) 
BPF_PROG_TYPE(BPF_PROG_TYPE_PERF_EVENT, perf_event)

BPF_PROG_TYPE(BPF_PROG_TYPE_RAW_TRACEPOINT, raw_tracepoint)

BPF_PROG_TYPE(BPF_PROG_TYPE_RAW_TRACEPOINT_WRITABLE, raw_tracepoint_writable)

BPF_PROG_TYPE(BPF_PROG_TYPE_TRACING, tracing)

#endif

#ifdef CONFIG_CGROUP_BPF

BPF_PROG_TYPE(BPF_PROG_TYPE_CGROUP_DEVICE, cg_dev)

include/uapi/linux/bpf.h

+2 −0
Original line number Diff line number Diff line
@@ -173,6 +173,7 @@ enum bpf_prog_type { 
	BPF_PROG_TYPE_CGROUP_SYSCTL,

	BPF_PROG_TYPE_RAW_TRACEPOINT_WRITABLE,

	BPF_PROG_TYPE_CGROUP_SOCKOPT,

	BPF_PROG_TYPE_TRACING,

};



enum bpf_attach_type {
@@ -199,6 +200,7 @@ enum bpf_attach_type { 
	BPF_CGROUP_UDP6_RECVMSG,

	BPF_CGROUP_GETSOCKOPT,

	BPF_CGROUP_SETSOCKOPT,

	BPF_TRACE_RAW_TP,

	__MAX_BPF_ATTACH_TYPE

};

kernel/bpf/syscall.c

+3 −3
Original line number Diff line number Diff line
@@ -1571,7 +1571,7 @@ bpf_prog_load_check_attach(enum bpf_prog_type prog_type, 
			   u32 btf_id)

{

	switch (prog_type) {

	case BPF_PROG_TYPE_RAW_TRACEPOINT:

	case BPF_PROG_TYPE_TRACING:

		if (btf_id > BTF_MAX_TYPE)

			return -EINVAL;

		break;
@@ -1833,13 +1833,13 @@ static int bpf_raw_tracepoint_open(const union bpf_attr *attr) 
		return PTR_ERR(prog);



	if (prog->type != BPF_PROG_TYPE_RAW_TRACEPOINT &&

	    prog->type != BPF_PROG_TYPE_TRACING &&

	    prog->type != BPF_PROG_TYPE_RAW_TRACEPOINT_WRITABLE) {

		err = -EINVAL;

		goto out_put_prog;

	}



	if (prog->type == BPF_PROG_TYPE_RAW_TRACEPOINT &&

	    prog->aux->attach_btf_id) {

	if (prog->type == BPF_PROG_TYPE_TRACING) {

		if (attr->raw_tracepoint.name) {

			/* raw_tp name should not be specified in raw_tp

			 * programs that were verified via in-kernel BTF info

kernel/bpf/verifier.c

+24 −10
Original line number Diff line number Diff line
@@ -9381,24 +9381,36 @@ static int check_attach_btf_id(struct bpf_verifier_env *env) 
{

	struct bpf_prog *prog = env->prog;

	u32 btf_id = prog->aux->attach_btf_id;

	const char prefix[] = "btf_trace_";

	const struct btf_type *t;

	const char *tname;



	if (prog->type == BPF_PROG_TYPE_RAW_TRACEPOINT && btf_id) {

		const char prefix[] = "btf_trace_";

	if (prog->type != BPF_PROG_TYPE_TRACING)

		return 0;



	if (!btf_id) {

		verbose(env, "Tracing programs must provide btf_id\n");

		return -EINVAL;

	}

	t = btf_type_by_id(btf_vmlinux, btf_id);

	if (!t) {

		verbose(env, "attach_btf_id %u is invalid\n", btf_id);

		return -EINVAL;

	}

	tname = btf_name_by_offset(btf_vmlinux, t->name_off);

	if (!tname) {

		verbose(env, "attach_btf_id %u doesn't have a name\n", btf_id);

		return -EINVAL;

	}



	switch (prog->expected_attach_type) {

	case BPF_TRACE_RAW_TP:

		if (!btf_type_is_typedef(t)) {

			verbose(env, "attach_btf_id %u is not a typedef\n",

				btf_id);

			return -EINVAL;

		}

		tname = btf_name_by_offset(btf_vmlinux, t->name_off);

		if (!tname || strncmp(prefix, tname, sizeof(prefix) - 1)) {

		if (strncmp(prefix, tname, sizeof(prefix) - 1)) {

			verbose(env, "attach_btf_id %u points to wrong type name %s\n",

				btf_id, tname);

			return -EINVAL;
@@ -9419,8 +9431,10 @@ static int check_attach_btf_id(struct bpf_verifier_env *env) 
		prog->aux->attach_func_name = tname;

		prog->aux->attach_func_proto = t;

		prog->aux->attach_btf_trace = true;

	}

		return 0;

	default:

		return -EINVAL;

	}

}



int bpf_check(struct bpf_prog **prog, union bpf_attr *attr,

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