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, 34 insertions, 0 deletions

diff --git a/drivers/md/dm-vdo/thread-device.c b/drivers/md/dm-vdo/thread-device.c
new file mode 100644
index 000000000..df13ca914
--- /dev/null
+++ b/drivers/md/dm-vdo/thread-device.c
@@ -0,0 +1,34 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright 2023 Red Hat
+ */
+
+#include "thread-device.h"
+
+/* A registry of threads associated with device id numbers. */
+static struct thread_registry device_id_thread_registry;
+
+/* Any registered thread must be unregistered. */
+void vdo_register_thread_device_id(struct registered_thread *new_thread,
+				   unsigned int *id_ptr)
+{
+	vdo_register_thread(&device_id_thread_registry, new_thread, id_ptr);
+}
+
+void vdo_unregister_thread_device_id(void)
+{
+	vdo_unregister_thread(&device_id_thread_registry);
+}
+
+int vdo_get_thread_device_id(void)
+{
+	const unsigned int *pointer;
+
+	pointer = vdo_lookup_thread(&device_id_thread_registry);
+	return (pointer != NULL) ? *pointer : -1;
+}
+
+void vdo_initialize_thread_device_registry(void)
+{
+	vdo_initialize_thread_registry(&device_id_thread_registry);
+}