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, 103 insertions, 0 deletions

diff --git a/fs/gfs2/dentry.c b/fs/gfs2/dentry.c
new file mode 100644
index 000000000..95050e719
--- /dev/null
+++ b/fs/gfs2/dentry.c
@@ -0,0 +1,103 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (C) Sistina Software, Inc.  1997-2003 All rights reserved.
+ * Copyright (C) 2004-2006 Red Hat, Inc.  All rights reserved.
+ */
+
+#include <linux/spinlock.h>
+#include <linux/completion.h>
+#include <linux/buffer_head.h>
+#include <linux/gfs2_ondisk.h>
+#include <linux/namei.h>
+#include <linux/crc32.h>
+
+#include "gfs2.h"
+#include "incore.h"
+#include "dir.h"
+#include "glock.h"
+#include "super.h"
+#include "util.h"
+#include "inode.h"
+
+/**
+ * gfs2_drevalidate - Check directory lookup consistency
+ * @dir: expected parent directory inode
+ * @name: expexted name
+ * @dentry: dentry to check
+ * @flags: lookup flags
+ *
+ * Check to make sure the lookup necessary to arrive at this inode from its
+ * parent is still good.
+ *
+ * Returns: 1 if the dentry is ok, 0 if it isn't
+ */
+
+static int gfs2_drevalidate(struct inode *dir, const struct qstr *name,
+			    struct dentry *dentry, unsigned int flags)
+{
+	struct gfs2_sbd *sdp = GFS2_SB(dir);
+	struct gfs2_inode *dip = GFS2_I(dir);
+	struct inode *inode;
+	struct gfs2_holder d_gh;
+	struct gfs2_inode *ip = NULL;
+	int error, valid;
+	int had_lock = 0;
+
+	if (flags & LOOKUP_RCU)
+		return -ECHILD;
+
+	inode = d_inode(dentry);
+
+	if (inode) {
+		if (is_bad_inode(inode))
+			return 0;
+		ip = GFS2_I(inode);
+	}
+
+	if (sdp->sd_lockstruct.ls_ops->lm_mount == NULL)
+		return 1;
+
+	had_lock = (gfs2_glock_is_locked_by_me(dip->i_gl) != NULL);
+	if (!had_lock) {
+		error = gfs2_glock_nq_init(dip->i_gl, LM_ST_SHARED, 0, &d_gh);
+		if (error)
+			return 0;
+	}
+
+	error = gfs2_dir_check(dir, name, ip);
+	valid = inode ? !error : (error == -ENOENT);
+
+	if (!had_lock)
+		gfs2_glock_dq_uninit(&d_gh);
+	return valid;
+}
+
+static int gfs2_dhash(const struct dentry *dentry, struct qstr *str)
+{
+	str->hash = gfs2_disk_hash(str->name, str->len);
+	return 0;
+}
+
+static int gfs2_dentry_delete(const struct dentry *dentry)
+{
+	struct gfs2_inode *ginode;
+
+	if (d_really_is_negative(dentry))
+		return 0;
+
+	ginode = GFS2_I(d_inode(dentry));
+	if (!gfs2_holder_initialized(&ginode->i_iopen_gh))
+		return 0;
+
+	if (test_bit(GLF_DEMOTE, &ginode->i_iopen_gh.gh_gl->gl_flags))
+		return 1;
+
+	return 0;
+}
+
+const struct dentry_operations gfs2_dops = {
+	.d_revalidate = gfs2_drevalidate,
+	.d_hash = gfs2_dhash,
+	.d_delete = gfs2_dentry_delete,
+};
+