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, 77 insertions, 0 deletions

diff --git a/net/mac80211/trace.c b/net/mac80211/trace.c
new file mode 100644
index 000000000..837857261
--- /dev/null
+++ b/net/mac80211/trace.c
@@ -0,0 +1,77 @@
+// SPDX-License-Identifier: GPL-2.0
+/* bug in tracepoint.h, it should include this */
+#include <linux/module.h>
+
+/* sparse isn't too happy with all macros... */
+#ifndef __CHECKER__
+#include <net/cfg80211.h>
+#include "driver-ops.h"
+#include "debug.h"
+#define CREATE_TRACE_POINTS
+#include "trace.h"
+#include "trace_msg.h"
+
+#ifdef CONFIG_MAC80211_MESSAGE_TRACING
+void __sdata_info(const char *fmt, ...)
+{
+	struct va_format vaf = {
+		.fmt = fmt,
+	};
+	va_list args;
+
+	va_start(args, fmt);
+	vaf.va = &args;
+
+	pr_info("%pV", &vaf);
+	trace_mac80211_info(&vaf);
+	va_end(args);
+}
+
+void __sdata_dbg(bool print, const char *fmt, ...)
+{
+	struct va_format vaf = {
+		.fmt = fmt,
+	};
+	va_list args;
+
+	va_start(args, fmt);
+	vaf.va = &args;
+
+	if (print)
+		pr_debug("%pV", &vaf);
+	trace_mac80211_dbg(&vaf);
+	va_end(args);
+}
+
+void __sdata_err(const char *fmt, ...)
+{
+	struct va_format vaf = {
+		.fmt = fmt,
+	};
+	va_list args;
+
+	va_start(args, fmt);
+	vaf.va = &args;
+
+	pr_err("%pV", &vaf);
+	trace_mac80211_err(&vaf);
+	va_end(args);
+}
+
+void __wiphy_dbg(struct wiphy *wiphy, bool print, const char *fmt, ...)
+{
+	struct va_format vaf = {
+		.fmt = fmt,
+	};
+	va_list args;
+
+	va_start(args, fmt);
+	vaf.va = &args;
+
+	if (print)
+		wiphy_dbg(wiphy, "%pV", &vaf);
+	trace_mac80211_dbg(&vaf);
+	va_end(args);
+}
+#endif
+#endif