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, 79 insertions, 0 deletions

diff --git a/drivers/mfd/mp2629.c b/drivers/mfd/mp2629.c
new file mode 100644
index 000000000..717b704c3
--- /dev/null
+++ b/drivers/mfd/mp2629.c
@@ -0,0 +1,79 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * MP2629 parent driver for ADC and battery charger
+ *
+ * Copyright 2020 Monolithic Power Systems, Inc
+ *
+ * Author: Saravanan Sekar <sravanhome@gmail.com>
+ */
+
+#include <linux/i2c.h>
+#include <linux/kernel.h>
+#include <linux/mfd/core.h>
+#include <linux/mfd/mp2629.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/regmap.h>
+#include <linux/slab.h>
+
+static const struct mfd_cell mp2629_cell[] = {
+	{
+		.name = "mp2629_adc",
+		.of_compatible = "mps,mp2629_adc",
+	},
+	{
+		.name = "mp2629_charger",
+		.of_compatible = "mps,mp2629_charger",
+	}
+};
+
+static const struct regmap_config mp2629_regmap_config = {
+	.reg_bits = 8,
+	.val_bits = 8,
+	.max_register = 0x17,
+};
+
+static int mp2629_probe(struct i2c_client *client)
+{
+	struct mp2629_data *ddata;
+	int ret;
+
+	ddata = devm_kzalloc(&client->dev, sizeof(*ddata), GFP_KERNEL);
+	if (!ddata)
+		return -ENOMEM;
+
+	ddata->dev = &client->dev;
+	i2c_set_clientdata(client, ddata);
+
+	ddata->regmap = devm_regmap_init_i2c(client, &mp2629_regmap_config);
+	if (IS_ERR(ddata->regmap)) {
+		dev_err(ddata->dev, "Failed to allocate regmap\n");
+		return PTR_ERR(ddata->regmap);
+	}
+
+	ret = devm_mfd_add_devices(ddata->dev, PLATFORM_DEVID_AUTO, mp2629_cell,
+				   ARRAY_SIZE(mp2629_cell), NULL, 0, NULL);
+	if (ret)
+		dev_err(ddata->dev, "Failed to register sub-devices %d\n", ret);
+
+	return ret;
+}
+
+static const struct of_device_id mp2629_of_match[] = {
+	{ .compatible = "mps,mp2629"},
+	{ }
+};
+MODULE_DEVICE_TABLE(of, mp2629_of_match);
+
+static struct i2c_driver mp2629_driver = {
+	.driver = {
+		.name = "mp2629",
+		.of_match_table = mp2629_of_match,
+	},
+	.probe		= mp2629_probe,
+};
+module_i2c_driver(mp2629_driver);
+
+MODULE_AUTHOR("Saravanan Sekar <sravanhome@gmail.com>");
+MODULE_DESCRIPTION("MP2629 Battery charger parent driver");
+MODULE_LICENSE("GPL");