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, 76 insertions, 0 deletions

diff --git a/sound/soc/sof/sof-utils.c b/sound/soc/sof/sof-utils.c
new file mode 100644
index 000000000..f70089317
--- /dev/null
+++ b/sound/soc/sof/sof-utils.c
@@ -0,0 +1,76 @@
+// SPDX-License-Identifier: (GPL-2.0-only OR BSD-3-Clause)
+//
+// This file is provided under a dual BSD/GPLv2 license.  When using or
+// redistributing this file, you may do so under either license.
+//
+// Copyright(c) 2018-2022 Intel Corporation
+//
+// Author: Keyon Jie <yang.jie@linux.intel.com>
+//
+
+#include <linux/unaligned.h>
+#include <linux/io-64-nonatomic-lo-hi.h>
+#include <linux/device.h>
+#include <sound/memalloc.h>
+#include <linux/module.h>
+#include "sof-utils.h"
+
+/*
+ * Generic buffer page table creation.
+ * Take the each physical page address and drop the least significant unused
+ * bits from each (based on PAGE_SIZE). Then pack valid page address bits
+ * into compressed page table.
+ */
+
+int snd_sof_create_page_table(struct device *dev,
+			      struct snd_dma_buffer *dmab,
+			      unsigned char *page_table, size_t size)
+{
+	int i, pages;
+
+	pages = snd_sgbuf_aligned_pages(size);
+
+	dev_dbg(dev, "generating page table for %p size 0x%zx pages %d\n",
+		dmab->area, size, pages);
+
+	for (i = 0; i < pages; i++) {
+		/*
+		 * The number of valid address bits for each page is 20.
+		 * idx determines the byte position within page_table
+		 * where the current page's address is stored
+		 * in the compressed page_table.
+		 * This can be calculated by multiplying the page number by 2.5.
+		 */
+		u32 idx = (5 * i) >> 1;
+		u32 pfn = snd_sgbuf_get_addr(dmab, i * PAGE_SIZE) >> PAGE_SHIFT;
+		u8 *pg_table;
+
+		pg_table = (u8 *)(page_table + idx);
+
+		/*
+		 * pagetable compression:
+		 * byte 0     byte 1     byte 2     byte 3     byte 4     byte 5
+		 * ___________pfn 0__________ __________pfn 1___________  _pfn 2...
+		 * .... ....  .... ....  .... ....  .... ....  .... ....  ....
+		 * It is created by:
+		 * 1. set current location to 0, PFN index i to 0
+		 * 2. put pfn[i] at current location in Little Endian byte order
+		 * 3. calculate an intermediate value as
+		 *    x = (pfn[i+1] << 4) | (pfn[i] & 0xf)
+		 * 4. put x at offset (current location + 2) in LE byte order
+		 * 5. increment current location by 5 bytes, increment i by 2
+		 * 6. continue to (2)
+		 */
+		if (i & 1)
+			put_unaligned_le32((pg_table[0] & 0xf) | pfn << 4,
+					   pg_table);
+		else
+			put_unaligned_le32(pfn, pg_table);
+	}
+
+	return pages;
+}
+EXPORT_SYMBOL(snd_sof_create_page_table);
+
+MODULE_LICENSE("Dual BSD/GPL");
+MODULE_DESCRIPTION("SOF utils");