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, 67 insertions, 0 deletions

diff --git a/Documentation/driver-api/w1.rst b/Documentation/driver-api/w1.rst
new file mode 100644
index 000000000..bda3ad60f
--- /dev/null
+++ b/Documentation/driver-api/w1.rst
@@ -0,0 +1,67 @@
+======================
+W1: Dallas' 1-wire bus
+======================
+
+:Author: David Fries
+
+W1 API internal to the kernel
+=============================
+
+include/linux/w1.h
+~~~~~~~~~~~~~~~~~~
+
+W1 kernel API functions.
+
+.. kernel-doc:: include/linux/w1.h
+   :internal:
+
+drivers/w1/w1.c
+~~~~~~~~~~~~~~~
+
+W1 core functions.
+
+.. kernel-doc:: drivers/w1/w1.c
+   :internal:
+
+drivers/w1/w1_family.c
+~~~~~~~~~~~~~~~~~~~~~~~
+
+Allows registering device family operations.
+
+.. kernel-doc:: drivers/w1/w1_family.c
+   :export:
+
+drivers/w1/w1_internal.h
+~~~~~~~~~~~~~~~~~~~~~~~~
+
+W1 internal initialization for master devices.
+
+.. kernel-doc:: drivers/w1/w1_internal.h
+   :internal:
+
+drivers/w1/w1_int.c
+~~~~~~~~~~~~~~~~~~~~
+
+W1 internal initialization for master devices.
+
+.. kernel-doc:: drivers/w1/w1_int.c
+   :export:
+
+drivers/w1/w1_netlink.h
+~~~~~~~~~~~~~~~~~~~~~~~~
+
+W1 external netlink API structures and commands.
+
+.. kernel-doc:: drivers/w1/w1_netlink.h
+   :internal:
+
+drivers/w1/w1_io.c
+~~~~~~~~~~~~~~~~~~~
+
+W1 input/output.
+
+.. kernel-doc:: drivers/w1/w1_io.c
+   :export:
+
+.. kernel-doc:: drivers/w1/w1_io.c
+   :internal: