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, 65 insertions, 0 deletions

diff --git a/drivers/tty/vt/Makefile b/drivers/tty/vt/Makefile
new file mode 100644
index 000000000..ae746dcde
--- /dev/null
+++ b/drivers/tty/vt/Makefile
@@ -0,0 +1,65 @@
+# SPDX-License-Identifier: GPL-2.0
+#
+# This file contains the font map for the default (hardware) font
+#
+FONTMAPFILE = cp437.uni
+
+obj-$(CONFIG_VT)			+= vt_ioctl.o vc_screen.o \
+					   selection.o keyboard.o \
+					   vt.o defkeymap.o
+obj-$(CONFIG_CONSOLE_TRANSLATIONS)	+= consolemap.o consolemap_deftbl.o \
+					   ucs.o
+
+# Files generated that shall be removed upon make clean
+clean-files :=	consolemap_deftbl.c defkeymap.c \
+		ucs_width_table.h ucs_recompose_table.h ucs_fallback_table.h
+
+hostprogs += conmakehash
+
+quiet_cmd_conmk = CONMK   $@
+      cmd_conmk = $(obj)/conmakehash $< > $@
+
+$(obj)/consolemap_deftbl.c: $(src)/$(FONTMAPFILE) $(obj)/conmakehash
+	$(call cmd,conmk)
+
+$(obj)/defkeymap.o:  $(obj)/defkeymap.c
+
+# Uncomment if you're changing the keymap and have an appropriate
+# loadkeys version for the map. By default, we'll use the shipped
+# versions.
+# GENERATE_KEYMAP := 1
+
+ifdef GENERATE_KEYMAP
+
+$(obj)/defkeymap.c: $(obj)/%.c: $(src)/%.map
+	loadkeys --mktable --unicode $< > $@
+
+endif
+
+$(obj)/ucs.o:	$(src)/ucs.c $(obj)/ucs_width_table.h \
+		$(obj)/ucs_recompose_table.h $(obj)/ucs_fallback_table.h
+
+# You may uncomment one of those to have the UCS tables be regenerated
+# during the build process. By default the _shipped versions are used.
+#
+#GENERATE_UCS_TABLES := 1
+#GENERATE_UCS_TABLES := 2  # invokes gen_ucs_recompose_table.py with --full
+
+ifdef GENERATE_UCS_TABLES
+
+$(obj)/ucs_width_table.h: $(src)/gen_ucs_width_table.py
+	$(PYTHON3) $< -o $@
+
+ifeq ($(GENERATE_UCS_TABLES),2)
+gen_recomp_arg := --full
+else
+gen_recomp_arg :=
+endif
+
+$(obj)/ucs_recompose_table.h: $(src)/gen_ucs_recompose_table.py
+	$(PYTHON3) $< -o $@ $(gen_recomp_arg)
+
+$(obj)/ucs_fallback_table.h: $(src)/gen_ucs_fallback_table.py
+	$(PYTHON3) $< -o $@
+
+endif