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

Alexei Starovoitov says:

====================
pull-request: bpf 2020-08-21

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

We've added 11 non-merge commits during the last 5 day(s) which contain
a total of 12 files changed, 78 insertions(+), 24 deletions(-).

The main changes are:

1) three fixes in BPF task iterator logic, from Yonghong.

2) fix for compressed dwarf sections in vmlinux, from Jiri.

3) fix xdp attach regression, from Andrii.
====================

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

8 files changed, 47 insertions, 10 deletions

diff --git a/tools/bpf/bpftool/pids.c b/tools/bpf/bpftool/pids.c
index e3b116325403..df7d8ec76036 100644
--- a/tools/bpf/bpftool/pids.c
+++ b/tools/bpf/bpftool/pids.c
@@ -134,6 +134,8 @@ int build_obj_refs_table(struct obj_refs_table *table, enum bpf_obj_type type)
 	while (true) {
 		ret = read(fd, buf, sizeof(buf));
 		if (ret < 0) {
+			if (errno == EAGAIN)
+				continue;
 			err = -errno;
 			p_err("failed to read PID iterator output: %d", err);
 			goto out;
diff --git a/tools/bpf/resolve_btfids/main.c b/tools/bpf/resolve_btfids/main.c
index 4d9ecb975862..0def0bb1f783 100644
--- a/tools/bpf/resolve_btfids/main.c
+++ b/tools/bpf/resolve_btfids/main.c
@@ -233,6 +233,39 @@ static struct btf_id *add_symbol(struct rb_root *root, char *name, size_t size)
 	return btf_id__add(root, id, false);
 }
 
+/*
+ * The data of compressed section should be aligned to 4
+ * (for 32bit) or 8 (for 64 bit) bytes. The binutils ld
+ * sets sh_addralign to 1, which makes libelf fail with
+ * misaligned section error during the update:
+ *    FAILED elf_update(WRITE): invalid section alignment
+ *
+ * While waiting for ld fix, we fix the compressed sections
+ * sh_addralign value manualy.
+ */
+static int compressed_section_fix(Elf *elf, Elf_Scn *scn, GElf_Shdr *sh)
+{
+	int expected = gelf_getclass(elf) == ELFCLASS32 ? 4 : 8;
+
+	if (!(sh->sh_flags & SHF_COMPRESSED))
+		return 0;
+
+	if (sh->sh_addralign == expected)
+		return 0;
+
+	pr_debug2(" - fixing wrong alignment sh_addralign %u, expected %u\n",
+		  sh->sh_addralign, expected);
+
+	sh->sh_addralign = expected;
+
+	if (gelf_update_shdr(scn, sh) == 0) {
+		printf("FAILED cannot update section header: %s\n",
+			elf_errmsg(-1));
+		return -1;
+	}
+	return 0;
+}
+
 static int elf_collect(struct object *obj)
 {
 	Elf_Scn *scn = NULL;
@@ -309,6 +342,9 @@ static int elf_collect(struct object *obj)
 			obj->efile.idlist_shndx = idx;
 			obj->efile.idlist_addr  = sh.sh_addr;
 		}
+
+		if (compressed_section_fix(elf, scn, &sh))
+			return -1;
 	}
 
 	return 0;
diff --git a/tools/include/uapi/linux/bpf.h b/tools/include/uapi/linux/bpf.h
index 0480f893facd..b6238b2209b7 100644
--- a/tools/include/uapi/linux/bpf.h
+++ b/tools/include/uapi/linux/bpf.h
@@ -767,7 +767,7 @@ union bpf_attr {
  *
  * 		Also, note that **bpf_trace_printk**\ () is slow, and should
  * 		only be used for debugging purposes. For this reason, a notice
- * 		bloc (spanning several lines) is printed to kernel logs and
+ * 		block (spanning several lines) is printed to kernel logs and
  * 		states that the helper should not be used "for production use"
  * 		the first time this helper is used (or more precisely, when
  * 		**trace_printk**\ () buffers are allocated). For passing values
@@ -1033,14 +1033,14 @@ union bpf_attr {
  *
  * 			int ret;
  * 			struct bpf_tunnel_key key = {};
- * 			
+ *
  * 			ret = bpf_skb_get_tunnel_key(skb, &key, sizeof(key), 0);
  * 			if (ret < 0)
  * 				return TC_ACT_SHOT;	// drop packet
- * 			
+ *
  * 			if (key.remote_ipv4 != 0x0a000001)
  * 				return TC_ACT_SHOT;	// drop packet
- * 			
+ *
  * 			return TC_ACT_OK;		// accept packet
  *
  * 		This interface can also be used with all encapsulation devices
@@ -1147,7 +1147,7 @@ union bpf_attr {
  * 	Description
  * 		Retrieve the realm or the route, that is to say the
  * 		**tclassid** field of the destination for the *skb*. The
- * 		indentifier retrieved is a user-provided tag, similar to the
+ * 		identifier retrieved is a user-provided tag, similar to the
  * 		one used with the net_cls cgroup (see description for
  * 		**bpf_get_cgroup_classid**\ () helper), but here this tag is
  * 		held by a route (a destination entry), not by a task.
diff --git a/tools/lib/bpf/btf_dump.c b/tools/lib/bpf/btf_dump.c
index fe39bd774697..57c00fa63932 100644
--- a/tools/lib/bpf/btf_dump.c
+++ b/tools/lib/bpf/btf_dump.c
@@ -879,7 +879,7 @@ static void btf_dump_emit_struct_def(struct btf_dump *d,
 			btf_dump_printf(d, ": %d", m_sz);
 			off = m_off + m_sz;
 		} else {
-			m_sz = max(0LL, btf__resolve_size(d->btf, m->type));
+			m_sz = max((__s64)0, btf__resolve_size(d->btf, m->type));
 			off = m_off + m_sz * 8;
 		}
 		btf_dump_printf(d, ";");
diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c
index 5d20b2da4427..0ad0b0491e1f 100644
--- a/tools/lib/bpf/libbpf.c
+++ b/tools/lib/bpf/libbpf.c
@@ -2264,7 +2264,7 @@ static int bpf_object__init_user_btf_maps(struct bpf_object *obj, bool strict,
 		data = elf_getdata(scn, NULL);
 	if (!scn || !data) {
 		pr_warn("failed to get Elf_Data from map section %d (%s)\n",
-			obj->efile.maps_shndx, MAPS_ELF_SEC);
+			obj->efile.btf_maps_shndx, MAPS_ELF_SEC);
 		return -EINVAL;
 	}
 
diff --git a/tools/testing/selftests/bpf/.gitignore b/tools/testing/selftests/bpf/.gitignore
index 1bb204cee853..9a0946ddb705 100644
--- a/tools/testing/selftests/bpf/.gitignore
+++ b/tools/testing/selftests/bpf/.gitignore
@@ -6,7 +6,6 @@ test_lpm_map
 test_tag
 FEATURE-DUMP.libbpf
 fixdep
-test_align
 test_dev_cgroup
 /test_progs*
 test_tcpbpf_user
diff --git a/tools/testing/selftests/bpf/Makefile b/tools/testing/selftests/bpf/Makefile
index a83b5827532f..fc946b7ac288 100644
--- a/tools/testing/selftests/bpf/Makefile
+++ b/tools/testing/selftests/bpf/Makefile
@@ -32,7 +32,7 @@ LDLIBS += -lcap -lelf -lz -lrt -lpthread
 
 # Order correspond to 'make run_tests' order
 TEST_GEN_PROGS = test_verifier test_tag test_maps test_lru_map test_lpm_map test_progs \
-	test_align test_verifier_log test_dev_cgroup test_tcpbpf_user \
+	test_verifier_log test_dev_cgroup test_tcpbpf_user \
 	test_sock test_btf test_sockmap get_cgroup_id_user test_socket_cookie \
 	test_cgroup_storage \
 	test_netcnt test_tcpnotify_user test_sock_fields test_sysctl \
diff --git a/tools/testing/selftests/bpf/prog_tests/test_global_funcs.c b/tools/testing/selftests/bpf/prog_tests/test_global_funcs.c
index 25b068591e9a..193002b14d7f 100644
--- a/tools/testing/selftests/bpf/prog_tests/test_global_funcs.c
+++ b/tools/testing/selftests/bpf/prog_tests/test_global_funcs.c
@@ -19,7 +19,7 @@ static int libbpf_debug_print(enum libbpf_print_level level,
 	log_buf = va_arg(args, char *);
 	if (!log_buf)
 		goto out;
-	if (strstr(log_buf, err_str) == 0)
+	if (err_str && strstr(log_buf, err_str) == 0)
 		found = true;
 out:
 	printf(format, log_buf);