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>

3 files changed, 207 insertions, 0 deletions

diff --git a/Documentation/devicetree/bindings/virtio/mmio.yaml b/Documentation/devicetree/bindings/virtio/mmio.yaml
new file mode 100644
index 000000000..0aa8433f0
--- /dev/null
+++ b/Documentation/devicetree/bindings/virtio/mmio.yaml
@@ -0,0 +1,67 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/virtio/mmio.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: virtio memory mapped devices
+
+maintainers:
+  - Jean-Philippe Brucker <jean-philippe@linaro.org>
+
+description:
+  See https://www.oasis-open.org/committees/tc_home.php?wg_abbrev=virtio for
+  more details.
+
+properties:
+  compatible:
+    const: virtio,mmio
+
+  reg:
+    maxItems: 1
+
+  dma-coherent: true
+
+  interrupts:
+    maxItems: 1
+
+  '#iommu-cells':
+    description: Required when the node corresponds to a virtio-iommu device.
+    const: 1
+
+  iommus:
+    description: Required for devices making accesses thru an IOMMU.
+    maxItems: 1
+
+  wakeup-source:
+    type: boolean
+    description: Required for setting irq of a virtio_mmio device as wakeup source.
+
+required:
+  - compatible
+  - reg
+  - interrupts
+
+additionalProperties:
+  type: object
+
+examples:
+  - |
+    virtio@3000 {
+        compatible = "virtio,mmio";
+        reg = <0x3000 0x100>;
+        interrupts = <41>;
+
+        /* Device has endpoint ID 23 */
+        iommus = <&viommu 23>;
+    };
+
+    viommu: iommu@3100 {
+        compatible = "virtio,mmio";
+        reg = <0x3100 0x100>;
+        interrupts = <42>;
+
+        #iommu-cells = <1>;
+    };
+
+...
diff --git a/Documentation/devicetree/bindings/virtio/pci-iommu.yaml b/Documentation/devicetree/bindings/virtio/pci-iommu.yaml
new file mode 100644
index 000000000..8bd6ad72a
--- /dev/null
+++ b/Documentation/devicetree/bindings/virtio/pci-iommu.yaml
@@ -0,0 +1,99 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/virtio/pci-iommu.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: virtio-iommu device using the virtio-pci transport
+
+maintainers:
+  - Jean-Philippe Brucker <jean-philippe@linaro.org>
+
+description: |
+  When virtio-iommu uses the PCI transport, its programming interface is
+  discovered dynamically by the PCI probing infrastructure. However the
+  device tree statically describes the relation between IOMMU and DMA
+  masters. Therefore, the PCI root complex that hosts the virtio-iommu
+  contains a child node representing the IOMMU device explicitly.
+
+  DMA from the IOMMU device isn't managed by another IOMMU. Therefore the
+  virtio-iommu node doesn't have an "iommus" property, and is omitted from
+  the iommu-map property of the root complex.
+
+allOf:
+  - $ref: /schemas/pci/pci-device.yaml#
+
+properties:
+  # If compatible is present, it should contain the vendor and device ID
+  # according to the PCI Bus Binding specification. Since PCI provides
+  # built-in identification methods, compatible is not actually required.
+  compatible:
+    oneOf:
+      - items:
+          - const: virtio,pci-iommu
+          - const: pci1af4,1057
+      - items:
+          - const: pci1af4,1057
+
+  reg:
+    maxItems: 1
+
+  '#iommu-cells':
+    const: 1
+
+required:
+  - compatible
+  - reg
+  - '#iommu-cells'
+
+additionalProperties: false
+
+examples:
+  - |
+    bus {
+        #address-cells = <2>;
+        #size-cells = <2>;
+
+        pcie@40000000 {
+            device_type = "pci";
+            #address-cells = <3>;
+            #size-cells = <2>;
+            reg = <0x0 0x40000000  0x0 0x1000000>;
+            ranges = <0x02000000 0x0 0x41000000  0x0 0x41000000  0x0 0x0f000000>;
+
+            /*
+             * The IOMMU manages all functions in this PCI domain except
+             * itself. Omit BDF 00:01.0.
+             */
+            iommu-map = <0x0 &iommu0 0x0 0x8
+                         0x9 &iommu0 0x9 0xfff7>;
+
+            /* The IOMMU programming interface uses slot 00:01.0 */
+            iommu0: iommu@1,0 {
+                compatible = "pci1af4,1057";
+                reg = <0x800 0 0 0 0>;
+                #iommu-cells = <1>;
+            };
+        };
+
+        pcie@50000000 {
+            device_type = "pci";
+            #address-cells = <3>;
+            #size-cells = <2>;
+            reg = <0x0 0x50000000  0x0 0x1000000>;
+            ranges = <0x02000000 0x0 0x51000000  0x0 0x51000000  0x0 0x0f000000>;
+
+            /*
+             * The IOMMU also manages all functions from this domain,
+             * with endpoint IDs 0x10000 - 0x1ffff
+             */
+            iommu-map = <0x0 &iommu0 0x10000 0x10000>;
+        };
+
+        ethernet {
+            /* The IOMMU manages this platform device with endpoint ID 0x20000 */
+            iommus = <&iommu0 0x20000>;
+        };
+    };
+
+...
diff --git a/Documentation/devicetree/bindings/virtio/virtio-device.yaml b/Documentation/devicetree/bindings/virtio/virtio-device.yaml
new file mode 100644
index 000000000..8c6919ba9
--- /dev/null
+++ b/Documentation/devicetree/bindings/virtio/virtio-device.yaml
@@ -0,0 +1,41 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/virtio/virtio-device.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Virtio device
+
+maintainers:
+  - Viresh Kumar <viresh.kumar@linaro.org>
+
+description:
+  These bindings are applicable to virtio devices irrespective of the bus they
+  are bound to, like mmio or pci.
+
+# We need a select here so we don't match all nodes with 'virtio,mmio'
+properties:
+  compatible:
+    pattern: "^virtio,device[0-9a-f]{1,8}$"
+    description: Virtio device nodes.
+      "virtio,deviceID", where ID is the virtio device id. The textual
+      representation of ID shall be in lower case hexadecimal with leading
+      zeroes suppressed.
+
+required:
+  - compatible
+
+additionalProperties: true
+
+examples:
+  - |
+    virtio@3000 {
+        compatible = "virtio,mmio";
+        reg = <0x3000 0x100>;
+        interrupts = <43>;
+
+        i2c {
+            compatible = "virtio,device22";
+        };
+    };
+...