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, 78 insertions, 0 deletions

diff --git a/samples/rust/rust_soc.rs b/samples/rust/rust_soc.rs
new file mode 100644
index 000000000..f5e5f2f9a
--- /dev/null
+++ b/samples/rust/rust_soc.rs
@@ -0,0 +1,78 @@
+// SPDX-License-Identifier: GPL-2.0
+
+//! Rust SoC Platform driver sample.
+
+use kernel::{
+    acpi,
+    device::Core,
+    of,
+    platform,
+    prelude::*,
+    soc,
+    str::CString,
+    sync::aref::ARef, //
+};
+use pin_init::pin_init_scope;
+
+#[pin_data]
+struct SampleSocDriver {
+    pdev: ARef<platform::Device>,
+    #[pin]
+    _dev_reg: soc::Registration,
+}
+
+kernel::of_device_table!(
+    OF_TABLE,
+    <SampleSocDriver as platform::Driver>::IdInfo,
+    [(of::DeviceId::new(c"test,rust-device"), ())]
+);
+
+kernel::acpi_device_table!(
+    ACPI_TABLE,
+    <SampleSocDriver as platform::Driver>::IdInfo,
+    [(acpi::DeviceId::new(c"LNUXBEEF"), ())]
+);
+
+impl platform::Driver for SampleSocDriver {
+    type IdInfo = ();
+    type Data<'bound> = Self;
+    const OF_ID_TABLE: Option<of::IdTable<Self::IdInfo>> = Some(&OF_TABLE);
+    const ACPI_ID_TABLE: Option<acpi::IdTable<Self::IdInfo>> = Some(&ACPI_TABLE);
+
+    fn probe<'bound>(
+        pdev: &'bound platform::Device<Core<'_>>,
+        _info: Option<&'bound Self::IdInfo>,
+    ) -> impl PinInit<Self, Error> + 'bound {
+        dev_dbg!(pdev, "Probe Rust SoC driver sample.\n");
+
+        let pdev = pdev.into();
+        pin_init_scope(move || {
+            let machine = CString::try_from(c"My cool ACME15 dev board")?;
+            let family = CString::try_from(c"ACME")?;
+            let revision = CString::try_from(c"1.2")?;
+            let serial_number = CString::try_from(c"12345")?;
+            let soc_id = CString::try_from(c"ACME15")?;
+
+            let attr = soc::Attributes {
+                machine: Some(machine),
+                family: Some(family),
+                revision: Some(revision),
+                serial_number: Some(serial_number),
+                soc_id: Some(soc_id),
+            };
+
+            Ok(try_pin_init!(SampleSocDriver {
+                pdev: pdev,
+                _dev_reg <- soc::Registration::new(attr),
+            }? Error))
+        })
+    }
+}
+
+kernel::module_platform_driver! {
+    type: SampleSocDriver,
+    name: "rust_soc",
+    authors: ["Matthew Maurer"],
+    description: "Rust SoC Driver",
+    license: "GPL",
+}