From 4617721c502b2ddaa4e324e86da4997edf738fa5 Mon Sep 17 00:00:00 2001 From: Steven Rostedt Date: Wed, 2 Sep 2026 09:55:01 -0400 Subject: ftrace: Synchronize the initialization of ftrace_ops There's some internal state that ftrace_ops needs to have set, but since it can be declared outside of the ftrace.c code, it calls ftrace_ops_init() on the ops in every global function. The issue is that if two tasks call it on the same ops at the same time it is possible to have the initialization of one corrupt the initialization of the other call. Create a ops_mutex to use to synchronize every initialization of the ftrace_ops. The mutex is taken within checking the ftrace_ops flag that states it was initializied but the flag is checked again after the mutex has been taken. Checking first outside the mutex allows it to shortcut having to take the mutex. But then the check needs to be done again after the mute is taken in case of races. Cc: stable@vger.kernel.org Link: https://patch.msgid.link/20260902095501.6b59af20@gandalf.local.home Fixes: f04f24fb7e48d ("ftrace, kprobes: Fix a deadlock on ftrace_regex_lock") Reported-by: sashiko-bot@kernel.org Close: https://lore.kernel.org/all/20260829025528.49A831F000E9@smtp.kernel.org/ Signed-off-by: Steven Rostedt --- fs/gfs2/dentry.c | 103 +++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 103 insertions(+) create mode 100644 fs/gfs2/dentry.c (limited to 'fs/gfs2/dentry.c') 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 +#include +#include +#include +#include +#include + +#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, +}; + -- cgit v1.3.1