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, 81 insertions, 0 deletions

diff --git a/arch/mips/rb532/setup.c b/arch/mips/rb532/setup.c
new file mode 100644
index 000000000..51af9d374
--- /dev/null
+++ b/arch/mips/rb532/setup.c
@@ -0,0 +1,81 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * setup.c - boot time setup code
+ */
+
+#include <linux/init.h>
+#include <linux/export.h>
+
+#include <asm/bootinfo.h>
+#include <asm/reboot.h>
+#include <asm/time.h>
+#include <linux/ioport.h>
+
+#include <asm/mach-rc32434/rb.h>
+#include <asm/mach-rc32434/pci.h>
+
+struct pci_reg __iomem *pci_reg;
+EXPORT_SYMBOL(pci_reg);
+
+static struct resource pci0_res[] = {
+	{
+		.name = "pci_reg0",
+		.start = PCI0_BASE_ADDR,
+		.end = PCI0_BASE_ADDR + sizeof(struct pci_reg),
+		.flags = IORESOURCE_MEM,
+	}
+};
+
+static void rb_machine_restart(char *command)
+{
+	/* just jump to the reset vector */
+	writel(0x80000001, IDT434_REG_BASE + RST);
+	((void (*)(void)) KSEG1ADDR(0x1FC00000u))();
+}
+
+static void rb_machine_halt(void)
+{
+	for (;;)
+		continue;
+}
+
+void __init plat_mem_setup(void)
+{
+	u32 val;
+
+	_machine_restart = rb_machine_restart;
+	_machine_halt = rb_machine_halt;
+	pm_power_off = rb_machine_halt;
+
+	set_io_port_base(KSEG1);
+
+	pci_reg = ioremap(pci0_res[0].start,
+				pci0_res[0].end - pci0_res[0].start);
+	if (!pci_reg) {
+		printk(KERN_ERR "Could not remap PCI registers\n");
+		return;
+	}
+
+	val = __raw_readl(&pci_reg->pcic);
+	val &= 0xFFFFFF7;
+	__raw_writel(val, (void *)&pci_reg->pcic);
+
+#ifdef CONFIG_PCI
+	/* Enable PCI interrupts in EPLD Mask register */
+	*epld_mask = 0x0;
+	*(epld_mask + 1) = 0x0;
+#endif
+	write_c0_wired(0);
+}
+
+const char *get_system_type(void)
+{
+	switch (mips_machtype) {
+	case MACH_MIKROTIK_RB532A:
+		return "Mikrotik RB532A";
+		break;
+	default:
+		return "Mikrotik RB532";
+		break;
+	}
+}