objtool: Validate disassembler headers in libopcodes probegrafted

commit 3f2de814c059 ("objtool: Fix libopcodes linking with static libraries")
tested for libopcodes availability by linking a test snippet with a forward
declaration of disassemble_init_for_target().

However, testing symbol linkage with an extern declaration only verifies
the presence of the library (.so/.a) and bypasses checking for development
headers (binutils-dev). On systems where libopcodes is present without
development headers installed, the probe succeeds, enabling BUILD_DISAS.
Subsequent compilation of objtool then fails:

  fatal error: 'bfd.h' file not found
    113 | #include <bfd.h>

Additionally, the probe invokes $(HOSTCC) without $(HOSTCFLAGS), ignoring
any sysroot or include flags specified for the host compiler.

Fix this by including <bfd.h> and <dis-asm.h> directly in the test snippet,
passing $(HOSTCFLAGS) so host compiler options are respected, and defining
PACKAGE="objtool" to satisfy the configuration check in <bfd.h>.

Fixes: 3f2de814c059 ("objtool: Fix libopcodes linking with static libraries")
Fixes: 436326bc525d ("objtool: fix build failure due to missing libopcodes check")
Reported-by: Alice Ryhl <aliceryhl@google.com>
Assisted-by: Antigravity:Gemini-Next
Signed-off-by: Ulises Mendez Martinez <umendez@google.com>
Link: https://patch.msgid.link/20260904150710.2997558-1-umendez@google.com
Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>

1 files changed, 41 insertions, 0 deletions

diff --git a/fs/unicode/Makefile b/fs/unicode/Makefile
new file mode 100644
index 000000000..d95be7fb9
--- /dev/null
+++ b/fs/unicode/Makefile
@@ -0,0 +1,41 @@
+# SPDX-License-Identifier: GPL-2.0
+
+ifneq ($(CONFIG_UNICODE),)
+obj-y			+= unicode.o
+endif
+obj-$(CONFIG_UNICODE)	+= utf8data.o
+obj-$(CONFIG_UNICODE_NORMALIZATION_KUNIT_TEST) += tests/utf8_kunit.o
+
+unicode-y := utf8-norm.o utf8-core.o
+
+$(obj)/utf8-data.o: $(obj)/utf8data.c
+
+# In the normal build, the checked-in utf8data.c is just shipped.
+#
+# To generate utf8data.c from UCD, put *.txt files in this directory
+# and pass REGENERATE_UTF8DATA=1 from the command line.
+ifdef REGENERATE_UTF8DATA
+
+quiet_cmd_utf8data = GEN     $@
+      cmd_utf8data = $< \
+		-a $(src)/DerivedAge.txt \
+		-c $(src)/DerivedCombiningClass.txt \
+		-p $(src)/DerivedCoreProperties.txt \
+		-d $(src)/UnicodeData.txt \
+		-f $(src)/CaseFolding.txt \
+		-n $(src)/NormalizationCorrections.txt \
+		-t $(src)/NormalizationTest.txt \
+		-o $@
+
+$(obj)/utf8data.c: $(obj)/mkutf8data $(filter %.txt, $(cmd_utf8data)) FORCE
+	$(call if_changed,utf8data)
+
+else
+
+$(obj)/utf8data.c: $(src)/utf8data.c_shipped FORCE
+	$(call if_changed,copy)
+
+endif
+
+targets += utf8data.c
+hostprogs += mkutf8data