Update Linux to v5.4.2

Change-Id: Idf6911045d9d382da2cfe01b1edff026404ac8fd
diff --git a/tools/lib/bpf/nlattr.h b/tools/lib/bpf/nlattr.h
index 931a71f..6cc3ac9 100644
--- a/tools/lib/bpf/nlattr.h
+++ b/tools/lib/bpf/nlattr.h
@@ -1,18 +1,13 @@
-/* SPDX-License-Identifier: LGPL-2.1 */
+/* SPDX-License-Identifier: (LGPL-2.1 OR BSD-2-Clause) */
 
 /*
  * NETLINK      Netlink attributes
  *
- *	This library is free software; you can redistribute it and/or
- *	modify it under the terms of the GNU Lesser General Public
- *	License as published by the Free Software Foundation version 2.1
- *	of the License.
- *
  * Copyright (c) 2003-2013 Thomas Graf <tgraf@suug.ch>
  */
 
-#ifndef __NLATTR_H
-#define __NLATTR_H
+#ifndef __LIBBPF_NLATTR_H
+#define __LIBBPF_NLATTR_H
 
 #include <stdint.h>
 #include <linux/netlink.h>
@@ -23,19 +18,19 @@
  * Standard attribute types to specify validation policy
  */
 enum {
-	NLA_UNSPEC,	/**< Unspecified type, binary data chunk */
-	NLA_U8,		/**< 8 bit integer */
-	NLA_U16,	/**< 16 bit integer */
-	NLA_U32,	/**< 32 bit integer */
-	NLA_U64,	/**< 64 bit integer */
-	NLA_STRING,	/**< NUL terminated character string */
-	NLA_FLAG,	/**< Flag */
-	NLA_MSECS,	/**< Micro seconds (64bit) */
-	NLA_NESTED,	/**< Nested attributes */
-	__NLA_TYPE_MAX,
+	LIBBPF_NLA_UNSPEC,	/**< Unspecified type, binary data chunk */
+	LIBBPF_NLA_U8,		/**< 8 bit integer */
+	LIBBPF_NLA_U16,		/**< 16 bit integer */
+	LIBBPF_NLA_U32,		/**< 32 bit integer */
+	LIBBPF_NLA_U64,		/**< 64 bit integer */
+	LIBBPF_NLA_STRING,	/**< NUL terminated character string */
+	LIBBPF_NLA_FLAG,	/**< Flag */
+	LIBBPF_NLA_MSECS,	/**< Micro seconds (64bit) */
+	LIBBPF_NLA_NESTED,	/**< Nested attributes */
+	__LIBBPF_NLA_TYPE_MAX,
 };
 
-#define NLA_TYPE_MAX (__NLA_TYPE_MAX - 1)
+#define LIBBPF_NLA_TYPE_MAX (__LIBBPF_NLA_TYPE_MAX - 1)
 
 /**
  * @ingroup attr
@@ -43,8 +38,8 @@
  *
  * See section @core_doc{core_attr_parse,Attribute Parsing} for more details.
  */
-struct nla_policy {
-	/** Type of attribute or NLA_UNSPEC */
+struct libbpf_nla_policy {
+	/** Type of attribute or LIBBPF_NLA_UNSPEC */
 	uint16_t	type;
 
 	/** Minimal length of payload required */
@@ -62,11 +57,50 @@
  * @arg len	length of attribute stream
  * @arg rem	initialized to len, holds bytes currently remaining in stream
  */
-#define nla_for_each_attr(pos, head, len, rem) \
+#define libbpf_nla_for_each_attr(pos, head, len, rem) \
 	for (pos = head, rem = len; \
 	     nla_ok(pos, rem); \
 	     pos = nla_next(pos, &(rem)))
 
-int nla_dump_errormsg(struct nlmsghdr *nlh);
+/**
+ * libbpf_nla_data - head of payload
+ * @nla: netlink attribute
+ */
+static inline void *libbpf_nla_data(const struct nlattr *nla)
+{
+	return (char *) nla + NLA_HDRLEN;
+}
 
-#endif /* __NLATTR_H */
+static inline uint8_t libbpf_nla_getattr_u8(const struct nlattr *nla)
+{
+	return *(uint8_t *)libbpf_nla_data(nla);
+}
+
+static inline uint32_t libbpf_nla_getattr_u32(const struct nlattr *nla)
+{
+	return *(uint32_t *)libbpf_nla_data(nla);
+}
+
+static inline const char *libbpf_nla_getattr_str(const struct nlattr *nla)
+{
+	return (const char *)libbpf_nla_data(nla);
+}
+
+/**
+ * libbpf_nla_len - length of payload
+ * @nla: netlink attribute
+ */
+static inline int libbpf_nla_len(const struct nlattr *nla)
+{
+	return nla->nla_len - NLA_HDRLEN;
+}
+
+int libbpf_nla_parse(struct nlattr *tb[], int maxtype, struct nlattr *head,
+		     int len, struct libbpf_nla_policy *policy);
+int libbpf_nla_parse_nested(struct nlattr *tb[], int maxtype,
+			    struct nlattr *nla,
+			    struct libbpf_nla_policy *policy);
+
+int libbpf_nla_dump_errormsg(struct nlmsghdr *nlh);
+
+#endif /* __LIBBPF_NLATTR_H */