Merge tag 'kbuild-fixes-v6.2-3' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild

Pull Kbuild fixes from Masahiro Yamada:

 - Hide LDFLAGS_vmlinux from decompressor Makefiles to fix error
   messages when GNU Make 4.4 is used.

 - Fix 'make modules' build error when CONFIG_DEBUG_INFO_BTF_MODULES=y.

 - Fix warnings emitted by GNU Make 4.4 in scripts/kconfig/Makefile.

 - Support GNU Make 4.4 for scripts/jobserver-exec.

 - Show clearer error message when kernel/gen_kheaders.sh fails due to
   missing cpio.

* tag 'kbuild-fixes-v6.2-3' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild:
  kheaders: explicitly validate existence of cpio command
  scripts: support GNU make 4.4 in jobserver-exec
  kconfig: Update all declared targets
  scripts: rpm: make clear that mkspec script contains 4.13 feature
  init/Kconfig: fix LOCALVERSION_AUTO help text
  kbuild: fix 'make modules' error when CONFIG_DEBUG_INFO_BTF_MODULES=y
  kbuild: export top-level LDFLAGS_vmlinux only to scripts/Makefile.vmlinux
  init/version-timestamp.c: remove unneeded #include <linux/version.h>
  docs: kbuild: remove mention to dropped $(objtree) feature

1 files changed, 14 insertions, 5 deletions

diff --git a/scripts/jobserver-exec b/scripts/jobserver-exec
index 4192855f5b8b..7eca035472d3 100755
--- a/scripts/jobserver-exec
+++ b/scripts/jobserver-exec
@@ -26,11 +26,20 @@ try:
 	# If the MAKEFLAGS variable contains multiple instances of the
 	# --jobserver-auth= option, the last one is relevant.
 	fds = opts[-1].split("=", 1)[1]
-	reader, writer = [int(x) for x in fds.split(",", 1)]
-	# Open a private copy of reader to avoid setting nonblocking
-	# on an unexpecting process with the same reader fd.
-	reader = os.open("/proc/self/fd/%d" % (reader),
-			 os.O_RDONLY | os.O_NONBLOCK)
+
+	# Starting with GNU Make 4.4, named pipes are used for reader and writer.
+	# Example argument: --jobserver-auth=fifo:/tmp/GMfifo8134
+	_, _, path = fds.partition('fifo:')
+
+	if path:
+		reader = os.open(path, os.O_RDONLY | os.O_NONBLOCK)
+		writer = os.open(path, os.O_WRONLY)
+	else:
+		reader, writer = [int(x) for x in fds.split(",", 1)]
+		# Open a private copy of reader to avoid setting nonblocking
+		# on an unexpecting process with the same reader fd.
+		reader = os.open("/proc/self/fd/%d" % (reader),
+				 os.O_RDONLY | os.O_NONBLOCK)
 
 	# Read out as many jobserver slots as possible.
 	while True: