kernel-selftest: Fix build on musl

* (Depends upon a linux-libc-headers patch proposed to oe-core)
* Delete unused patch
* Mark Clang 6.0 as minimum required version
* Do not hardcode python3 interpreter path

Signed-off-by: Khem Raj <raj.khem@gmail.com>
Cc: Hongzhi.Song <hongzhi.song@windriver.com>
Cc: Martin Jansa <Martin.Jansa@gmail.com>

meta-oe/recipes-kernel/kernel-selftest/kernel-selftest.bb

@@ -9,7 +9,6 @@ DEPENDS = "rsync-native"
 # for musl libc
 SRC_URI_append_libc-musl = "\
                       file://userfaultfd.patch \
-                      file://0001-bpf-test_progs.c-add-support-for-musllibc.patch \
                       "
 SRC_URI += "file://run-ptest \
             file://COPYING \
@@ -62,7 +61,7 @@ python __anonymous () {
 }
 
 do_compile() {
-    bbwarn "clang with bpf support is needed with kernel 4.18+ so \
+    bbwarn "clang >= 6.0  with bpf support is needed with kernel 4.18+ so \
 either install it and add it to HOSTTOOLS, or add \
 clang-native from meta-clang to dependency"
     for i in ${TEST_LIST}
@@ -76,7 +75,9 @@ do_install() {
     do
         oe_runmake -C ${S}/tools/testing/selftests/${i} INSTALL_PATH=${D}/usr/kernel-selftest/${i} install
     done
-
+    if [ -e ${D}/usr/kernel-selftest/bpf/test_offload.py ]; then
+	sed -i -e '1s,#!.*python3,#! /usr/bin/env python3,' ${D}/usr/kernel-selftest/bpf/test_offload.py
+    fi
     chown root:root  -R ${D}/usr/kernel-selftest
 }
 
@@ -115,5 +116,6 @@ PACKAGE_ARCH = "${MACHINE_ARCH}"
 INHIBIT_PACKAGE_DEBUG_SPLIT="1"
 FILES_${PN} += "/usr/kernel-selftest"
 
+RDEPENDS_${PN} += "python3"
 # tools/testing/selftests/vm/Makefile doesn't respect LDFLAGS and tools/testing/selftests/Makefile explicitly overrides to empty
 INSANE_SKIP_${PN} += "ldflags"

meta-oe/recipes-kernel/kernel-selftest/kernel-selftest/0001-bpf-test_progs.c-add-support-for-musllibc.patch

@@ -1,25 +0,0 @@
-From a2e6b8fde28b743b69990a4e16c296e099631ed4 Mon Sep 17 00:00:00 2001
-From: "Hongzhi.Song" <hongzhi.song@windriver.com>
-Date: Mon, 23 Jul 2018 00:56:19 -0700
-Subject: [PATCH] bpf: test_progs.c add support for musllibc
-
-Signed-off-by: Hongzhi.Song <hongzhi.song@windriver.com>
----
- tools/testing/selftests/bpf/test_progs.c | 1 +
- 1 file changed, 1 insertion(+)
-
-diff --git a/tools/testing/selftests/bpf/test_progs.c b/tools/testing/selftests/bpf/test_progs.c
-index 11ee25c..21b27b7 100644
---- a/tools/testing/selftests/bpf/test_progs.c
-+++ b/tools/testing/selftests/bpf/test_progs.c
-@@ -4,6 +4,7 @@
-  * modify it under the terms of version 2 of the GNU General Public
-  * License as published by the Free Software Foundation.
-  */
-+#define __always_inline __inline __attribute__ ((__always_inline__))
- #include <stdio.h>
- #include <unistd.h>
- #include <errno.h>
--- 
-2.11.0
-

meta-oe/recipes-kernel/kernel-selftest/kernel-selftest/0001-swap.h-micro-define-to-support-musl-libc.patch

@@ -1,26 +0,0 @@
-From c21dfb0dfdfec281479e267ad7fe9a8d4ba15a70 Mon Sep 17 00:00:00 2001
-From: "Hongzhi.Song" <hongzhi.song@windriver.com>
-Date: Tue, 17 Jul 2018 23:47:48 -0700
-Subject: [PATCH] add micro define to support musl libc
-
-Signed-off-by: Hongzhi.Song <hongzhi.song@windriver.com>
----
- recipe-sysroot/usr/include/linux/swab.h | 2 ++
- 1 file changed, 2 insertions(+)
-
-diff --git a/recipe-sysroot/usr/include/linux/swab.h b/recipe-sysroot/usr/include/linux/swab.h
-index afb7eb7..33efa10 100644
---- a/recipe-sysroot/usr/include/linux/swab.h
-+++ b/recipe-sysroot/usr/include/linux/swab.h
-@@ -6,6 +6,8 @@
- 
- #include <asm/swab.h>
- 
-+#define __always_inline __inline __attribute__ ((__always_inline__))
-+
- /*
-  * casts are necessary for constants, because we never know how for sure
-  * how U/UL/ULL map to __u16, __u32, __u64. At least not in a portable way.
--- 
-2.11.0
-