Update Linux to v5.4.2

Change-Id: Idf6911045d9d382da2cfe01b1edff026404ac8fd
diff --git a/tools/perf/util/util.h b/tools/perf/util/util.h
index dc58254..9969b8b 100644
--- a/tools/perf/util/util.h
+++ b/tools/perf/util/util.h
@@ -6,10 +6,9 @@
 /* glibc 2.20 deprecates _BSD_SOURCE in favour of _DEFAULT_SOURCE */
 #define _DEFAULT_SOURCE 1
 
+#include <fcntl.h>
 #include <stdbool.h>
 #include <stddef.h>
-#include <stdlib.h>
-#include <stdarg.h>
 #include <linux/compiler.h>
 #include <sys/types.h>
 
@@ -17,33 +16,16 @@
 void usage(const char *err) __noreturn;
 void die(const char *err, ...) __noreturn __printf(1, 2);
 
-static inline void *zalloc(size_t size)
-{
-	return calloc(1, size);
-}
-
-#define zfree(ptr) ({ free(*ptr); *ptr = NULL; })
-
 struct dirent;
-struct nsinfo;
 struct strlist;
 
 int mkdir_p(char *path, mode_t mode);
 int rm_rf(const char *path);
+int rm_rf_perf_data(const char *path);
 struct strlist *lsdir(const char *name, bool (*filter)(const char *, struct dirent *));
 bool lsdir_no_dot_filter(const char *name, struct dirent *d);
-int copyfile(const char *from, const char *to);
-int copyfile_mode(const char *from, const char *to, mode_t mode);
-int copyfile_ns(const char *from, const char *to, struct nsinfo *nsi);
-
-ssize_t readn(int fd, void *buf, size_t n);
-ssize_t writen(int fd, const void *buf, size_t n);
 
 size_t hex_width(u64 v);
-int hex2u64(const char *ptr, u64 *val);
-
-extern unsigned int page_size;
-int __pure cacheline_size(void);
 
 int sysctl__max_stack(void);
 
@@ -61,15 +43,13 @@
 int sched_getcpu(void);
 #endif
 
-#ifndef HAVE_SETNS_SUPPORT
-int setns(int fd, int nstype);
-#endif
-
 extern bool perf_singlethreaded;
 
 void perf_set_singlethreaded(void);
 void perf_set_multithreaded(void);
 
+char *perf_exe(char *buf, int len);
+
 #ifndef O_CLOEXEC
 #ifdef __sparc__
 #define O_CLOEXEC      0x400000