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, 158 insertions, 0 deletions

diff --git a/net/ethtool/wol.c b/net/ethtool/wol.c
new file mode 100644
index 000000000..60f9a1d85
--- /dev/null
+++ b/net/ethtool/wol.c
@@ -0,0 +1,158 @@
+// SPDX-License-Identifier: GPL-2.0-only
+
+#include "bitset.h"
+#include "common.h"
+#include "netlink.h"
+
+struct wol_req_info {
+	struct ethnl_req_info		base;
+};
+
+struct wol_reply_data {
+	struct ethnl_reply_data		base;
+	struct ethtool_wolinfo		wol;
+	bool				show_sopass;
+};
+
+#define WOL_REPDATA(__reply_base) \
+	container_of(__reply_base, struct wol_reply_data, base)
+
+const struct nla_policy ethnl_wol_get_policy[] = {
+	[ETHTOOL_A_WOL_HEADER]		=
+		NLA_POLICY_NESTED(ethnl_header_policy),
+};
+
+static int wol_prepare_data(const struct ethnl_req_info *req_base,
+			    struct ethnl_reply_data *reply_base,
+			    const struct genl_info *info)
+{
+	struct wol_reply_data *data = WOL_REPDATA(reply_base);
+	struct net_device *dev = reply_base->dev;
+	int ret;
+
+	if (!dev->ethtool_ops->get_wol)
+		return -EOPNOTSUPP;
+
+	ret = ethnl_ops_begin(dev);
+	if (ret < 0)
+		return ret;
+	dev->ethtool_ops->get_wol(dev, &data->wol);
+	ethnl_ops_complete(dev);
+	/* do not include password in notifications */
+	data->show_sopass = !genl_info_is_ntf(info) &&
+		(data->wol.supported & WAKE_MAGICSECURE);
+
+	return 0;
+}
+
+static int wol_reply_size(const struct ethnl_req_info *req_base,
+			  const struct ethnl_reply_data *reply_base)
+{
+	bool compact = req_base->flags & ETHTOOL_FLAG_COMPACT_BITSETS;
+	const struct wol_reply_data *data = WOL_REPDATA(reply_base);
+	int len;
+
+	len = ethnl_bitset32_size(&data->wol.wolopts, &data->wol.supported,
+				  WOL_MODE_COUNT, wol_mode_names, compact);
+	if (len < 0)
+		return len;
+	if (data->show_sopass)
+		len += nla_total_size(sizeof(data->wol.sopass));
+
+	return len;
+}
+
+static int wol_fill_reply(struct sk_buff *skb,
+			  const struct ethnl_req_info *req_base,
+			  const struct ethnl_reply_data *reply_base)
+{
+	bool compact = req_base->flags & ETHTOOL_FLAG_COMPACT_BITSETS;
+	const struct wol_reply_data *data = WOL_REPDATA(reply_base);
+	int ret;
+
+	ret = ethnl_put_bitset32(skb, ETHTOOL_A_WOL_MODES, &data->wol.wolopts,
+				 &data->wol.supported, WOL_MODE_COUNT,
+				 wol_mode_names, compact);
+	if (ret < 0)
+		return ret;
+	if (data->show_sopass &&
+	    nla_put(skb, ETHTOOL_A_WOL_SOPASS, sizeof(data->wol.sopass),
+		    data->wol.sopass))
+		return -EMSGSIZE;
+
+	return 0;
+}
+
+/* WOL_SET */
+
+const struct nla_policy ethnl_wol_set_policy[] = {
+	[ETHTOOL_A_WOL_HEADER]		=
+		NLA_POLICY_NESTED(ethnl_header_policy),
+	[ETHTOOL_A_WOL_MODES]		= { .type = NLA_NESTED },
+	[ETHTOOL_A_WOL_SOPASS]		= { .type = NLA_BINARY,
+					    .len = SOPASS_MAX },
+};
+
+static int
+ethnl_set_wol_validate(struct ethnl_req_info *req_info, struct genl_info *info)
+{
+	const struct ethtool_ops *ops = req_info->dev->ethtool_ops;
+
+	return ops->get_wol && ops->set_wol ? 1 : -EOPNOTSUPP;
+}
+
+static int
+ethnl_set_wol(struct ethnl_req_info *req_info, struct genl_info *info)
+{
+	struct ethtool_wolinfo wol = { .cmd = ETHTOOL_GWOL };
+	struct net_device *dev = req_info->dev;
+	struct nlattr **tb = info->attrs;
+	bool mod = false;
+	int ret;
+
+	dev->ethtool_ops->get_wol(dev, &wol);
+	ret = ethnl_update_bitset32(&wol.wolopts, WOL_MODE_COUNT,
+				    tb[ETHTOOL_A_WOL_MODES], wol_mode_names,
+				    info->extack, &mod);
+	if (ret < 0)
+		return ret;
+	if (wol.wolopts & ~wol.supported) {
+		NL_SET_ERR_MSG_ATTR(info->extack, tb[ETHTOOL_A_WOL_MODES],
+				    "cannot enable unsupported WoL mode");
+		return -EINVAL;
+	}
+	if (tb[ETHTOOL_A_WOL_SOPASS]) {
+		if (!(wol.supported & WAKE_MAGICSECURE)) {
+			NL_SET_ERR_MSG_ATTR(info->extack,
+					    tb[ETHTOOL_A_WOL_SOPASS],
+					    "magicsecure not supported, cannot set password");
+			return -EINVAL;
+		}
+		ethnl_update_binary(wol.sopass, sizeof(wol.sopass),
+				    tb[ETHTOOL_A_WOL_SOPASS], &mod);
+	}
+
+	if (!mod)
+		return 0;
+	ret = dev->ethtool_ops->set_wol(dev, &wol);
+	if (ret)
+		return ret;
+	dev->ethtool->wol_enabled = !!wol.wolopts;
+	return 1;
+}
+
+const struct ethnl_request_ops ethnl_wol_request_ops = {
+	.request_cmd		= ETHTOOL_MSG_WOL_GET,
+	.reply_cmd		= ETHTOOL_MSG_WOL_GET_REPLY,
+	.hdr_attr		= ETHTOOL_A_WOL_HEADER,
+	.req_info_size		= sizeof(struct wol_req_info),
+	.reply_data_size	= sizeof(struct wol_reply_data),
+
+	.prepare_data		= wol_prepare_data,
+	.reply_size		= wol_reply_size,
+	.fill_reply		= wol_fill_reply,
+
+	.set_validate		= ethnl_set_wol_validate,
+	.set			= ethnl_set_wol,
+	.set_ntf_cmd		= ETHTOOL_MSG_WOL_NTF,
+};