Merge https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next

Alexei Starovoitov says:

====================
pull-request: bpf-next 2021-09-17

We've added 63 non-merge commits during the last 12 day(s) which contain
a total of 65 files changed, 2653 insertions(+), 751 deletions(-).

The main changes are:

1) Streamline internal BPF program sections handling and
   bpf_program__set_attach_target() in libbpf, from Andrii.

2) Add support for new btf kind BTF_KIND_TAG, from Yonghong.

3) Introduce bpf_get_branch_snapshot() to capture LBR, from Song.

4) IMUL optimization for x86-64 JIT, from Jie.

5) xsk selftest improvements, from Magnus.

6) Introduce legacy kprobe events support in libbpf, from Rafael.

7) Access hw timestamp through BPF's __sk_buff, from Vadim.

* https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next: (63 commits)
  selftests/bpf: Fix a few compiler warnings
  libbpf: Constify all high-level program attach APIs
  libbpf: Schedule open_opts.attach_prog_fd deprecation since v0.7
  selftests/bpf: Switch fexit_bpf2bpf selftest to set_attach_target() API
  libbpf: Allow skipping attach_func_name in bpf_program__set_attach_target()
  libbpf: Deprecated bpf_object_open_opts.relaxed_core_relocs
  selftests/bpf: Stop using relaxed_core_relocs which has no effect
  libbpf: Use pre-setup sec_def in libbpf_find_attach_btf_id()
  bpf: Update bpf_get_smp_processor_id() documentation
  libbpf: Add sphinx code documentation comments
  selftests/bpf: Skip btf_tag test if btf_tag attribute not supported
  docs/bpf: Add documentation for BTF_KIND_TAG
  selftests/bpf: Add a test with a bpf program with btf_tag attributes
  selftests/bpf: Test BTF_KIND_TAG for deduplication
  selftests/bpf: Add BTF_KIND_TAG unit tests
  selftests/bpf: Change NAME_NTH/IS_NAME_NTH for BTF_KIND_TAG format
  selftests/bpf: Test libbpf API function btf__add_tag()
  bpftool: Add support for BTF_KIND_TAG
  libbpf: Add support for BTF_KIND_TAG
  libbpf: Rename btf_{hash,equal}_int to btf_{hash,equal}_int_tag
  ...
====================

Link: https://lore.kernel.org/r/20210917173738.3397064-1-ast@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

1 files changed, 30 insertions, 0 deletions

diff --git a/kernel/trace/bpf_trace.c b/kernel/trace/bpf_trace.c
index 8e2eb950aa82..067e88c3d2ee 100644
--- a/kernel/trace/bpf_trace.c
+++ b/kernel/trace/bpf_trace.c
@@ -1017,6 +1017,34 @@ static const struct bpf_func_proto bpf_get_attach_cookie_proto_pe = {
 	.arg1_type	= ARG_PTR_TO_CTX,
 };
 
+BPF_CALL_3(bpf_get_branch_snapshot, void *, buf, u32, size, u64, flags)
+{
+#ifndef CONFIG_X86
+	return -ENOENT;
+#else
+	static const u32 br_entry_size = sizeof(struct perf_branch_entry);
+	u32 entry_cnt = size / br_entry_size;
+
+	entry_cnt = static_call(perf_snapshot_branch_stack)(buf, entry_cnt);
+
+	if (unlikely(flags))
+		return -EINVAL;
+
+	if (!entry_cnt)
+		return -ENOENT;
+
+	return entry_cnt * br_entry_size;
+#endif
+}
+
+static const struct bpf_func_proto bpf_get_branch_snapshot_proto = {
+	.func		= bpf_get_branch_snapshot,
+	.gpl_only	= true,
+	.ret_type	= RET_INTEGER,
+	.arg1_type	= ARG_PTR_TO_UNINIT_MEM,
+	.arg2_type	= ARG_CONST_SIZE_OR_ZERO,
+};
+
 static const struct bpf_func_proto *
 bpf_tracing_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog)
 {
@@ -1132,6 +1160,8 @@ bpf_tracing_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog)
 		return &bpf_snprintf_proto;
 	case BPF_FUNC_get_func_ip:
 		return &bpf_get_func_ip_proto_tracing;
+	case BPF_FUNC_get_branch_snapshot:
+		return &bpf_get_branch_snapshot_proto;
 	default:
 		return bpf_base_func_proto(func_id);
 	}