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, 27 insertions, 0 deletions

diff --git a/drivers/of/Makefile b/drivers/of/Makefile
new file mode 100644
index 000000000..379a0afcb
--- /dev/null
+++ b/drivers/of/Makefile
@@ -0,0 +1,27 @@
+# SPDX-License-Identifier: GPL-2.0
+obj-y = base.o cpu.o device.o module.o platform.o property.o
+obj-$(CONFIG_OF_KOBJ) += kobj.o
+obj-$(CONFIG_OF_DYNAMIC) += dynamic.o
+obj-$(CONFIG_OF_FLATTREE) += fdt.o empty_root.dtb.o
+obj-$(CONFIG_OF_EARLY_FLATTREE) += fdt_address.o
+obj-$(CONFIG_OF_PROMTREE) += pdt.o
+obj-$(CONFIG_OF_ADDRESS)  += address.o
+obj-$(CONFIG_OF_IRQ)    += irq.o
+obj-$(CONFIG_OF_UNITTEST) += unittest.o
+obj-$(CONFIG_OF_RESERVED_MEM) += of_reserved_mem.o
+obj-$(CONFIG_OF_RESOLVE)  += resolver.o
+obj-$(CONFIG_OF_OVERLAY) += overlay.o
+obj-$(CONFIG_OF_NUMA) += of_numa.o
+
+ifdef CONFIG_KEXEC_FILE
+ifdef CONFIG_OF_FLATTREE
+obj-y	+= kexec.o
+endif
+endif
+
+obj-$(CONFIG_KUNIT) += of_kunit_helpers.o
+obj-$(CONFIG_OF_KUNIT_TEST) += of_test.o
+obj-$(CONFIG_OF_OVERLAY_KUNIT_TEST) += overlay-test.o
+overlay-test-y := overlay_test.o kunit_overlay_test.dtbo.o
+
+obj-$(CONFIG_OF_UNITTEST) += unittest-data/