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, 32 insertions, 0 deletions

diff --git a/scripts/ssl-common.h b/scripts/ssl-common.h
new file mode 100644
index 000000000..2db0e1811
--- /dev/null
+++ b/scripts/ssl-common.h
@@ -0,0 +1,32 @@
+/* SPDX-License-Identifier: LGPL-2.1+ */
+/*
+ * SSL helper functions shared by sign-file and extract-cert.
+ */
+
+static void drain_openssl_errors(int l, int silent)
+{
+	const char *file;
+	char buf[120];
+	int e, line;
+
+	if (ERR_peek_error() == 0)
+		return;
+	if (!silent)
+		fprintf(stderr, "At main.c:%d:\n", l);
+
+	while ((e = ERR_peek_error_line(&file, &line))) {
+		ERR_error_string(e, buf);
+		if (!silent)
+			fprintf(stderr, "- SSL %s: %s:%d\n", buf, file, line);
+		ERR_get_error();
+	}
+}
+
+#define ERR(cond, fmt, ...)				\
+	do {						\
+		bool __cond = (cond);			\
+		drain_openssl_errors(__LINE__, 0);	\
+		if (__cond) {				\
+			errx(1, fmt, ## __VA_ARGS__);	\
+		}					\
+	} while (0)