Merge git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf

Daniel Borkmann says:

====================
pull-request: bpf 2018-02-09

The following pull-request contains BPF updates for your *net* tree.

The main changes are:

1) Two fixes for BPF sockmap in order to break up circular map references
   from programs attached to sockmap, and detaching related sockets in
   case of socket close() event. For the latter we get rid of the
   smap_state_change() and plug into ULP infrastructure, which will later
   also be used for additional features anyway such as TX hooks. For the
   second issue, dependency chain is broken up via map release callback
   to free parse/verdict programs, all from John.

2) Fix a libbpf relocation issue that was found while implementing XDP
   support for Suricata project. Issue was that when clang was invoked
   with default target instead of bpf target, then various other e.g.
   debugging relevant sections are added to the ELF file that contained
   relocation entries pointing to non-BPF related sections which libbpf
   trips over instead of skipping them. Test cases for libbpf are added
   as well, from Jesper.

3) Various misc fixes for bpftool and one for libbpf: a small addition
   to libbpf to make sure it recognizes all standard section prefixes.
   Then, the Makefile in bpftool/Documentation is improved to explicitly
   check for rst2man being installed on the system as we otherwise risk
   installing empty man pages; the man page for bpftool-map is corrected
   and a set of missing bash completions added in order to avoid shipping
   bpftool where the completions are only partially working, from Quentin.

4) Fix applying the relocation to immediate load instructions in the
   nfp JIT which were missing a shift, from Jakub.

5) Two fixes for the BPF kernel selftests: handle CONFIG_BPF_JIT_ALWAYS_ON=y
   gracefully in test_bpf.ko module and mark them as FLAG_EXPECTED_FAIL
   in this case; and explicitly delete the veth devices in the two tests
   test_xdp_{meta,redirect}.sh before dismantling the netnses as when
   selftests are run in batch mode, then workqueue to handle destruction
   might not have finished yet and thus veth creation in next test under
   same dev name would fail, from Yonghong.

6) Fix test_kmod.sh to check the test_bpf.ko module path before performing
   an insmod, and fallback to modprobe. Especially the latter is useful
   when having a device under test that has the modules installed instead,
   from Naresh.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 44 insertions, 12 deletions

diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c
index 71ddc48..97073d6 100644
--- a/tools/lib/bpf/libbpf.c
+++ b/tools/lib/bpf/libbpf.c
@@ -319,8 +319,8 @@ bpf_program__init(void *data, size_t size, char *section_name, int idx,
 
 	prog->section_name = strdup(section_name);
 	if (!prog->section_name) {
-		pr_warning("failed to alloc name for prog under section %s\n",
-			   section_name);
+		pr_warning("failed to alloc name for prog under section(%d) %s\n",
+			   idx, section_name);
 		goto errout;
 	}
 
@@ -742,6 +742,24 @@ bpf_object__init_maps(struct bpf_object *obj)
 	return 0;
 }
 
+static bool section_have_execinstr(struct bpf_object *obj, int idx)
+{
+	Elf_Scn *scn;
+	GElf_Shdr sh;
+
+	scn = elf_getscn(obj->efile.elf, idx);
+	if (!scn)
+		return false;
+
+	if (gelf_getshdr(scn, &sh) != &sh)
+		return false;
+
+	if (sh.sh_flags & SHF_EXECINSTR)
+		return true;
+
+	return false;
+}
+
 static int bpf_object__elf_collect(struct bpf_object *obj)
 {
 	Elf *elf = obj->efile.elf;
@@ -763,29 +781,29 @@ static int bpf_object__elf_collect(struct bpf_object *obj)
 
 		idx++;
 		if (gelf_getshdr(scn, &sh) != &sh) {
-			pr_warning("failed to get section header from %s\n",
-				   obj->path);
+			pr_warning("failed to get section(%d) header from %s\n",
+				   idx, obj->path);
 			err = -LIBBPF_ERRNO__FORMAT;
 			goto out;
 		}
 
 		name = elf_strptr(elf, ep->e_shstrndx, sh.sh_name);
 		if (!name) {
-			pr_warning("failed to get section name from %s\n",
-				   obj->path);
+			pr_warning("failed to get section(%d) name from %s\n",
+				   idx, obj->path);
 			err = -LIBBPF_ERRNO__FORMAT;
 			goto out;
 		}
 
 		data = elf_getdata(scn, 0);
 		if (!data) {
-			pr_warning("failed to get section data from %s(%s)\n",
-				   name, obj->path);
+			pr_warning("failed to get section(%d) data from %s(%s)\n",
+				   idx, name, obj->path);
 			err = -LIBBPF_ERRNO__FORMAT;
 			goto out;
 		}
-		pr_debug("section %s, size %ld, link %d, flags %lx, type=%d\n",
-			 name, (unsigned long)data->d_size,
+		pr_debug("section(%d) %s, size %ld, link %d, flags %lx, type=%d\n",
+			 idx, name, (unsigned long)data->d_size,
 			 (int)sh.sh_link, (unsigned long)sh.sh_flags,
 			 (int)sh.sh_type);
 
@@ -825,6 +843,14 @@ static int bpf_object__elf_collect(struct bpf_object *obj)
 		} else if (sh.sh_type == SHT_REL) {
 			void *reloc = obj->efile.reloc;
 			int nr_reloc = obj->efile.nr_reloc + 1;
+			int sec = sh.sh_info; /* points to other section */
+
+			/* Only do relo for section with exec instructions */
+			if (!section_have_execinstr(obj, sec)) {
+				pr_debug("skip relo %s(%d) for section(%d)\n",
+					 name, idx, sec);
+				continue;
+			}
 
 			reloc = realloc(reloc,
 					sizeof(*obj->efile.reloc) * nr_reloc);
@@ -840,6 +866,8 @@ static int bpf_object__elf_collect(struct bpf_object *obj)
 				obj->efile.reloc[n].shdr = sh;
 				obj->efile.reloc[n].data = data;
 			}
+		} else {
+			pr_debug("skip section(%d) %s\n", idx, name);
 		}
 		if (err)
 			goto out;
@@ -1119,8 +1147,7 @@ static int bpf_object__collect_reloc(struct bpf_object *obj)
 
 		prog = bpf_object__find_prog_by_idx(obj, idx);
 		if (!prog) {
-			pr_warning("relocation failed: no %d section\n",
-				   idx);
+			pr_warning("relocation failed: no section(%d)\n", idx);
 			return -LIBBPF_ERRNO__RELOC;
 		}
 
@@ -1816,12 +1843,17 @@ static const struct {
 	BPF_PROG_SEC("socket",		BPF_PROG_TYPE_SOCKET_FILTER),
 	BPF_PROG_SEC("kprobe/",		BPF_PROG_TYPE_KPROBE),
 	BPF_PROG_SEC("kretprobe/",	BPF_PROG_TYPE_KPROBE),
+	BPF_PROG_SEC("classifier",	BPF_PROG_TYPE_SCHED_CLS),
+	BPF_PROG_SEC("action",		BPF_PROG_TYPE_SCHED_ACT),
 	BPF_PROG_SEC("tracepoint/",	BPF_PROG_TYPE_TRACEPOINT),
 	BPF_PROG_SEC("xdp",		BPF_PROG_TYPE_XDP),
 	BPF_PROG_SEC("perf_event",	BPF_PROG_TYPE_PERF_EVENT),
 	BPF_PROG_SEC("cgroup/skb",	BPF_PROG_TYPE_CGROUP_SKB),
 	BPF_PROG_SEC("cgroup/sock",	BPF_PROG_TYPE_CGROUP_SOCK),
 	BPF_PROG_SEC("cgroup/dev",	BPF_PROG_TYPE_CGROUP_DEVICE),
+	BPF_PROG_SEC("lwt_in",		BPF_PROG_TYPE_LWT_IN),
+	BPF_PROG_SEC("lwt_out",		BPF_PROG_TYPE_LWT_OUT),
+	BPF_PROG_SEC("lwt_xmit",	BPF_PROG_TYPE_LWT_XMIT),
 	BPF_PROG_SEC("sockops",		BPF_PROG_TYPE_SOCK_OPS),
 	BPF_PROG_SEC("sk_skb",		BPF_PROG_TYPE_SK_SKB),
 };