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, 72 insertions, 0 deletions

diff --git a/Documentation/process/maintainer-devicetree.rst b/Documentation/process/maintainer-devicetree.rst
new file mode 100644
index 000000000..ecc3ed638
--- /dev/null
+++ b/Documentation/process/maintainer-devicetree.rst
@@ -0,0 +1,72 @@
+.. SPDX-License-Identifier: GPL-2.0
+
+======================================
+Devicetree and Open Firmware Subsystem
+======================================
+
+Other Process Documents
+-----------------------
+
+Please see the documents in Documentation/devicetree/bindings/ for information
+on how to write proper Devicetree bindings and how to submit patches.
+
+Patch Review and Handling
+-------------------------
+
+Patches handled by Devicetree maintainers are processed differently depending
+on the patch type:
+
+1. Core OF driver code, e.g. drivers/of/:
+   patches are reviewed and applied by DT maintainers.
+
+2. Devicetree bindings:
+   patches are reviewed by DT maintainers, but should be applied by subsystem
+   maintainers except in certain cases.  See also *For kernel maintainers* in
+   Documentation/devicetree/bindings/submitting-patches.rst.
+
+3. DTS and drivers:
+   DT maintainers might provide comments, but review is generally not expected.
+   DTS must pass schema checks (dtbs_check) or at least do not add any
+   new warnings.
+
+Patchwork
+~~~~~~~~~
+
+Devicetree maintainers review patches using Patchwork, so the current status of
+a patch can be checked there. For typical driver submissions, Patchwork
+receives the entire patch set, but only a few patches are usually Devicetree
+bindings that are reviewed by DT maintainers.
+
+Explanation of Patchwork statuses:
+
+ - **New**: Not yet processed by the automation toolset.
+ - **Needs ACK**: Waiting for review by DT maintainers.
+ - **Handled Elsewhere**: Non-DT patch; not being reviewed here.
+ - **RFC**: Patch was likely ignored because it was an incomplete RFC.
+ - **Changes Requested**: Patch was reviewed and DT maintainers expect changes.
+ - **Accepted**: Patch was reviewed and applied by DT maintainers to their tree.
+ - **Not Applicable**: Patch was reviewed and is likely in good shape, with a
+   *Reviewed-by* or *Acked-by* tag provided, but DT maintainers expect someone
+   else to apply it.
+
+Patch Re-review and Pinging
+~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+Due to the high volume of email traffic, Devicetree maintainers do not read
+every email they receive and instead rely on Patchwork during the review
+process. They also often skip patches that have already been reviewed.
+
+As a result, maintainers might miss:
+
+1. Questions about already reviewed patches.
+2. Pings, for example when a patch has been reviewed by DT maintainers but has
+   not been picked up by subsystem maintainers.
+
+Such cases can be addressed by:
+
+1. Pinging DT maintainers on the IRC channel.
+2. Dropping the DT maintainer’s *Acked-by* or *Reviewed-by* tag when sending a new
+   version of the patch set, together with an explanation in the patch
+   changelog describing why the tag was removed and what is expected from DT
+   maintainers.
+