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, 123 insertions, 0 deletions

diff --git a/fs/squashfs/lzo_wrapper.c b/fs/squashfs/lzo_wrapper.c
new file mode 100644
index 000000000..be1df7a25
--- /dev/null
+++ b/fs/squashfs/lzo_wrapper.c
@@ -0,0 +1,123 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Squashfs - a compressed read only filesystem for Linux
+ *
+ * Copyright (c) 2010 LG Electronics
+ * Chan Jeong <chan.jeong@lge.com>
+ *
+ * lzo_wrapper.c
+ */
+
+#include <linux/mutex.h>
+#include <linux/bio.h>
+#include <linux/slab.h>
+#include <linux/vmalloc.h>
+#include <linux/lzo.h>
+
+#include "squashfs_fs.h"
+#include "squashfs_fs_sb.h"
+#include "squashfs.h"
+#include "decompressor.h"
+#include "page_actor.h"
+
+struct squashfs_lzo {
+	void	*input;
+	void	*output;
+};
+
+static void *lzo_init(struct squashfs_sb_info *msblk, void *buff)
+{
+	int block_size = max_t(int, msblk->block_size, SQUASHFS_METADATA_SIZE);
+
+	struct squashfs_lzo *stream = kzalloc_obj(*stream);
+	if (stream == NULL)
+		goto failed;
+	stream->input = vmalloc(block_size);
+	if (stream->input == NULL)
+		goto failed;
+	stream->output = vmalloc(block_size);
+	if (stream->output == NULL)
+		goto failed2;
+
+	return stream;
+
+failed2:
+	vfree(stream->input);
+failed:
+	ERROR("Failed to allocate lzo workspace\n");
+	kfree(stream);
+	return ERR_PTR(-ENOMEM);
+}
+
+
+static void lzo_free(void *strm)
+{
+	struct squashfs_lzo *stream = strm;
+
+	if (stream) {
+		vfree(stream->input);
+		vfree(stream->output);
+	}
+	kfree(stream);
+}
+
+
+static int lzo_uncompress(struct squashfs_sb_info *msblk, void *strm,
+	struct bio *bio, int offset, int length,
+	struct squashfs_page_actor *output)
+{
+	struct bvec_iter_all iter_all = {};
+	struct bio_vec *bvec = bvec_init_iter_all(&iter_all);
+	struct squashfs_lzo *stream = strm;
+	void *buff = stream->input, *data;
+	int bytes = length, res;
+	size_t out_len = output->length;
+
+	while (bio_next_segment(bio, &iter_all)) {
+		int avail = min(bytes, ((int)bvec->bv_len) - offset);
+
+		data = bvec_virt(bvec);
+		memcpy(buff, data + offset, avail);
+		buff += avail;
+		bytes -= avail;
+		offset = 0;
+	}
+
+	res = lzo1x_decompress_safe(stream->input, (size_t)length,
+					stream->output, &out_len);
+	if (res != LZO_E_OK)
+		goto failed;
+
+	res = bytes = (int)out_len;
+	data = squashfs_first_page(output);
+	buff = stream->output;
+	while (data) {
+		if (bytes <= PAGE_SIZE) {
+			if (!IS_ERR(data))
+				memcpy(data, buff, bytes);
+			break;
+		} else {
+			if (!IS_ERR(data))
+				memcpy(data, buff, PAGE_SIZE);
+			buff += PAGE_SIZE;
+			bytes -= PAGE_SIZE;
+			data = squashfs_next_page(output);
+		}
+	}
+	squashfs_finish_page(output);
+
+	return res;
+
+failed:
+	return -EIO;
+}
+
+const struct squashfs_decompressor squashfs_lzo_comp_ops = {
+	.init = lzo_init,
+	.free = lzo_free,
+	.decompress = lzo_uncompress,
+	.id = LZO_COMPRESSION,
+	.name = "lzo",
+	.alloc_buffer = 0,
+	.supported = 1
+};