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

Alexei Starovoitov says:

====================
pull-request: bpf-next 2021-12-30

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

We've added 72 non-merge commits during the last 20 day(s) which contain
a total of 223 files changed, 3510 insertions(+), 1591 deletions(-).

The main changes are:

1) Automatic setrlimit in libbpf when bpf is memcg's in the kernel, from Andrii.

2) Beautify and de-verbose verifier logs, from Christy.

3) Composable verifier types, from Hao.

4) bpf_strncmp helper, from Hou.

5) bpf.h header dependency cleanup, from Jakub.

6) get_func_[arg|ret|arg_cnt] helpers, from Jiri.

7) Sleepable local storage, from KP.

8) Extend kfunc with PTR_TO_CTX, PTR_TO_MEM argument support, from Kumar.
====================

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

1 files changed, 41 insertions, 44 deletions

diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c
index 902f1ad5b7e6..9cb99d1e2385 100644
--- a/tools/lib/bpf/libbpf.c
+++ b/tools/lib/bpf/libbpf.c
@@ -187,42 +187,6 @@ const char *libbpf_version_string(void)
 #undef __S
 }
 
-enum kern_feature_id {
-	/* v4.14: kernel support for program & map names. */
-	FEAT_PROG_NAME,
-	/* v5.2: kernel support for global data sections. */
-	FEAT_GLOBAL_DATA,
-	/* BTF support */
-	FEAT_BTF,
-	/* BTF_KIND_FUNC and BTF_KIND_FUNC_PROTO support */
-	FEAT_BTF_FUNC,
-	/* BTF_KIND_VAR and BTF_KIND_DATASEC support */
-	FEAT_BTF_DATASEC,
-	/* BTF_FUNC_GLOBAL is supported */
-	FEAT_BTF_GLOBAL_FUNC,
-	/* BPF_F_MMAPABLE is supported for arrays */
-	FEAT_ARRAY_MMAP,
-	/* kernel support for expected_attach_type in BPF_PROG_LOAD */
-	FEAT_EXP_ATTACH_TYPE,
-	/* bpf_probe_read_{kernel,user}[_str] helpers */
-	FEAT_PROBE_READ_KERN,
-	/* BPF_PROG_BIND_MAP is supported */
-	FEAT_PROG_BIND_MAP,
-	/* Kernel support for module BTFs */
-	FEAT_MODULE_BTF,
-	/* BTF_KIND_FLOAT support */
-	FEAT_BTF_FLOAT,
-	/* BPF perf link support */
-	FEAT_PERF_LINK,
-	/* BTF_KIND_DECL_TAG support */
-	FEAT_BTF_DECL_TAG,
-	/* BTF_KIND_TYPE_TAG support */
-	FEAT_BTF_TYPE_TAG,
-	__FEAT_CNT,
-};
-
-static bool kernel_supports(const struct bpf_object *obj, enum kern_feature_id feat_id);
-
 enum reloc_type {
 	RELO_LD64,
 	RELO_CALL,
@@ -831,11 +795,36 @@ bpf_object__add_programs(struct bpf_object *obj, Elf_Data *sec_data,
 	return 0;
 }
 
-static __u32 get_kernel_version(void)
+__u32 get_kernel_version(void)
 {
+	/* On Ubuntu LINUX_VERSION_CODE doesn't correspond to info.release,
+	 * but Ubuntu provides /proc/version_signature file, as described at
+	 * https://ubuntu.com/kernel, with an example contents below, which we
+	 * can use to get a proper LINUX_VERSION_CODE.
+	 *
+	 *   Ubuntu 5.4.0-12.15-generic 5.4.8
+	 *
+	 * In the above, 5.4.8 is what kernel is actually expecting, while
+	 * uname() call will return 5.4.0 in info.release.
+	 */
+	const char *ubuntu_kver_file = "/proc/version_signature";
 	__u32 major, minor, patch;
 	struct utsname info;
 
+	if (access(ubuntu_kver_file, R_OK) == 0) {
+		FILE *f;
+
+		f = fopen(ubuntu_kver_file, "r");
+		if (f) {
+			if (fscanf(f, "%*s %*s %d.%d.%d\n", &major, &minor, &patch) == 3) {
+				fclose(f);
+				return KERNEL_VERSION(major, minor, patch);
+			}
+			fclose(f);
+		}
+		/* something went wrong, fall back to uname() approach */
+	}
+
 	uname(&info);
 	if (sscanf(info.release, "%u.%u.%u", &major, &minor, &patch) != 3)
 		return 0;
@@ -1201,12 +1190,10 @@ static struct bpf_object *bpf_object__new(const char *path,
 
 	strcpy(obj->path, path);
 	if (obj_name) {
-		strncpy(obj->name, obj_name, sizeof(obj->name) - 1);
-		obj->name[sizeof(obj->name) - 1] = 0;
+		libbpf_strlcpy(obj->name, obj_name, sizeof(obj->name));
 	} else {
 		/* Using basename() GNU version which doesn't modify arg. */
-		strncpy(obj->name, basename((void *)path),
-			sizeof(obj->name) - 1);
+		libbpf_strlcpy(obj->name, basename((void *)path), sizeof(obj->name));
 		end = strchr(obj->name, '.');
 		if (end)
 			*end = 0;
@@ -1358,7 +1345,10 @@ static int bpf_object__check_endianness(struct bpf_object *obj)
 static int
 bpf_object__init_license(struct bpf_object *obj, void *data, size_t size)
 {
-	memcpy(obj->license, data, min(size, sizeof(obj->license) - 1));
+	/* libbpf_strlcpy() only copies first N - 1 bytes, so size + 1 won't
+	 * go over allowed ELF data section buffer
+	 */
+	libbpf_strlcpy(obj->license, data, min(size + 1, sizeof(obj->license)));
 	pr_debug("license of %s is %s\n", obj->path, obj->license);
 	return 0;
 }
@@ -4354,6 +4344,10 @@ bpf_object__probe_loading(struct bpf_object *obj)
 	if (obj->gen_loader)
 		return 0;
 
+	ret = bump_rlimit_memlock();
+	if (ret)
+		pr_warn("Failed to bump RLIMIT_MEMLOCK (err = %d), you might need to do it explicitly!\n", ret);
+
 	/* make sure basic loading works */
 	ret = bpf_prog_load(BPF_PROG_TYPE_SOCKET_FILTER, NULL, "GPL", insns, insn_cnt, NULL);
 	if (ret < 0)
@@ -4720,14 +4714,17 @@ static struct kern_feature_desc {
 	[FEAT_BTF_TYPE_TAG] = {
 		"BTF_KIND_TYPE_TAG support", probe_kern_btf_type_tag,
 	},
+	[FEAT_MEMCG_ACCOUNT] = {
+		"memcg-based memory accounting", probe_memcg_account,
+	},
 };
 
-static bool kernel_supports(const struct bpf_object *obj, enum kern_feature_id feat_id)
+bool kernel_supports(const struct bpf_object *obj, enum kern_feature_id feat_id)
 {
 	struct kern_feature_desc *feat = &feature_probes[feat_id];
 	int ret;
 
-	if (obj->gen_loader)
+	if (obj && obj->gen_loader)
 		/* To generate loader program assume the latest kernel
 		 * to avoid doing extra prog_load, map_create syscalls.
 		 */