Kbuild fixes for 6.18 #1

- Fix UAPI types check in headers_check.pl
 
 - Only enable -Werror for hostprogs with CONFIG_WERROR / W=e
 
 - Ignore fsync() error when output of gen_init_cpio is a pipe
 
 - Several little build fixes for recent modules.builtin.modinfo series
 
 Signed-off-by: Nathan Chancellor <nathan@kernel.org>
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Merge tag 'kbuild-fixes-6.18-1' of git://git.kernel.org/pub/scm/linux/kernel/git/kbuild/linux

Pull Kbuild fixes from Nathan Chancellor:

 - Fix UAPI types check in headers_check.pl

 - Only enable -Werror for hostprogs with CONFIG_WERROR / W=e

 - Ignore fsync() error when output of gen_init_cpio is a pipe

 - Several little build fixes for recent modules.builtin.modinfo series

* tag 'kbuild-fixes-6.18-1' of git://git.kernel.org/pub/scm/linux/kernel/git/kbuild/linux:
  kbuild: Use '--strip-unneeded-symbol' for removing module device table symbols
  s390/vmlinux.lds.S: Move .vmlinux.info to end of allocatable sections
  kbuild: Add '.rel.*' strip pattern for vmlinux
  kbuild: Restore pattern to avoid stripping .rela.dyn from vmlinux
  gen_init_cpio: Ignore fsync() returning EINVAL on pipes
  scripts/Makefile.extrawarn: Respect CONFIG_WERROR / W=e for hostprogs
  kbuild: uapi: Strip comments before size type check

arch/s390/kernel/vmlinux.lds.S

@@ -214,6 +214,28 @@ SECTIONS
 	DWARF_DEBUG
 	ELF_DETAILS
 
+	/*
+	 * Make sure that the .got.plt is either completely empty or it
+	 * contains only the three reserved double words.
+	 */
+	.got.plt : {
+		*(.got.plt)
+	}
+	ASSERT(SIZEOF(.got.plt) == 0 || SIZEOF(.got.plt) == 0x18, "Unexpected GOT/PLT entries detected!")
+
+	/*
+	 * Sections that should stay zero sized, which is safer to
+	 * explicitly check instead of blindly discarding.
+	 */
+	.plt : {
+		*(.plt) *(.plt.*) *(.iplt) *(.igot .igot.plt)
+	}
+	ASSERT(SIZEOF(.plt) == 0, "Unexpected run-time procedure linkages detected!")
+	.rela.dyn : {
+		*(.rela.*) *(.rela_*)
+	}
+	ASSERT(SIZEOF(.rela.dyn) == 0, "Unexpected run-time relocations (.rela) detected!")
+
 	/*
 	 * uncompressed image info used by the decompressor
 	 * it should match struct vmlinux_info
@@ -244,28 +266,6 @@ SECTIONS
 #endif
 	} :NONE
 
-	/*
-	 * Make sure that the .got.plt is either completely empty or it
-	 * contains only the three reserved double words.
-	 */
-	.got.plt : {
-		*(.got.plt)
-	}
-	ASSERT(SIZEOF(.got.plt) == 0 || SIZEOF(.got.plt) == 0x18, "Unexpected GOT/PLT entries detected!")
-
-	/*
-	 * Sections that should stay zero sized, which is safer to
-	 * explicitly check instead of blindly discarding.
-	 */
-	.plt : {
-		*(.plt) *(.plt.*) *(.iplt) *(.igot .igot.plt)
-	}
-	ASSERT(SIZEOF(.plt) == 0, "Unexpected run-time procedure linkages detected!")
-	.rela.dyn : {
-		*(.rela.*) *(.rela_*)
-	}
-	ASSERT(SIZEOF(.rela.dyn) == 0, "Unexpected run-time relocations (.rela) detected!")
-
 	/* Sections to be discarded */
 	DISCARDS
 	/DISCARD/ : {

scripts/Makefile.extrawarn

@@ -223,9 +223,11 @@ KBUILD_USERCFLAGS	+= -Werror
 KBUILD_USERLDFLAGS	+= -Wl,--fatal-warnings
 KBUILD_RUSTFLAGS	+= -Dwarnings
 
-endif
+# While hostprog flags are used during build bootstrapping (thus should not
-
+# depend on CONFIG_ symbols), -Werror is disruptive and should be opted into.
-# Hostprog flags are used during build bootstrapping and can not rely on CONFIG_ symbols.
+# Only apply -Werror to hostprogs built after the initial Kconfig stage.
 KBUILD_HOSTCFLAGS	+= -Werror
 KBUILD_HOSTLDFLAGS	+= -Wl,--fatal-warnings
 KBUILD_HOSTRUSTFLAGS	+= -Dwarnings
+
+endif

scripts/Makefile.vmlinux

@@ -82,9 +82,12 @@ endif
 # ---------------------------------------------------------------------------
 
 remove-section-y                                   := .modinfo
-remove-section-$(CONFIG_ARCH_VMLINUX_NEEDS_RELOCS) += '.rel*'
+remove-section-$(CONFIG_ARCH_VMLINUX_NEEDS_RELOCS) += '.rel*' '!.rel*.dyn'
+# for compatibility with binutils < 2.32
+# https://sourceware.org/git/?p=binutils-gdb.git;a=commit;h=c12d9fa2afe7abcbe407a00e15719e1a1350c2a7
+remove-section-$(CONFIG_ARCH_VMLINUX_NEEDS_RELOCS) += '.rel.*'
 
-remove-symbols := -w --strip-symbol='__mod_device_table__*'
+remove-symbols := -w --strip-unneeded-symbol='__mod_device_table__*'
 
 # To avoid warnings: "empty loadable segment detected at ..." from GNU objcopy,
 # it is necessary to remove the PT_LOAD flag from the segment.

usr/gen_init_cpio.c

@@ -112,7 +112,10 @@ static int cpio_trailer(void)
 	    push_pad(padlen(offset, 512)) < 0)
 		return -1;
 
-	return fsync(outfd);
+	if (fsync(outfd) < 0 && errno != EINVAL)
+		return -1;
+
+	return 0;
 }
 
 static int cpio_mkslink(const char *name, const char *target,

usr/include/headers_check.pl

@@ -155,6 +155,8 @@ sub check_sizetypes
 	if (my $included = ($line =~ /^\s*#\s*include\s+[<"](\S+)[>"]/)[0]) {
 		check_include_typesh($included);
 	}
+	# strip single-line comments, as types may be referenced within them
+	$line =~ s@/\*.*?\*/@@;
 	if ($line =~ m/__[us](8|16|32|64)\b/) {
 		printf STDERR "$filename:$lineno: " .
 		              "found __[us]{8,16,32,64} type " .