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/dlm/memory.c | 179 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 179 insertions(+) create mode 100644 fs/dlm/memory.c (limited to 'fs/dlm/memory.c') diff --git a/fs/dlm/memory.c b/fs/dlm/memory.c new file mode 100644 index 000000000..ee55994ce --- /dev/null +++ b/fs/dlm/memory.c @@ -0,0 +1,179 @@ +// SPDX-License-Identifier: GPL-2.0-only +/****************************************************************************** +******************************************************************************* +** +** Copyright (C) Sistina Software, Inc. 1997-2003 All rights reserved. +** Copyright (C) 2004-2007 Red Hat, Inc. All rights reserved. +** +** +******************************************************************************* +******************************************************************************/ + +#include "dlm_internal.h" +#include "midcomms.h" +#include "lowcomms.h" +#include "config.h" +#include "memory.h" +#include "ast.h" + +static struct kmem_cache *writequeue_cache; +static struct kmem_cache *mhandle_cache; +static struct kmem_cache *msg_cache; +static struct kmem_cache *lkb_cache; +static struct kmem_cache *rsb_cache; +static struct kmem_cache *cb_cache; + + +int __init dlm_memory_init(void) +{ + writequeue_cache = dlm_lowcomms_writequeue_cache_create(); + if (!writequeue_cache) + goto out; + + mhandle_cache = dlm_midcomms_cache_create(); + if (!mhandle_cache) + goto mhandle; + + lkb_cache = kmem_cache_create("dlm_lkb", sizeof(struct dlm_lkb), + __alignof__(struct dlm_lkb), 0, NULL); + if (!lkb_cache) + goto lkb; + + msg_cache = dlm_lowcomms_msg_cache_create(); + if (!msg_cache) + goto msg; + + rsb_cache = kmem_cache_create("dlm_rsb", sizeof(struct dlm_rsb), + __alignof__(struct dlm_rsb), 0, NULL); + if (!rsb_cache) + goto rsb; + + cb_cache = kmem_cache_create_usercopy("dlm_cb", sizeof(struct dlm_callback), + __alignof__(struct dlm_callback), 0, + offsetof(struct dlm_callback, lvbptr), + sizeof_field(struct dlm_callback, lvbptr), + NULL); + if (!cb_cache) + goto cb; + + return 0; + +cb: + kmem_cache_destroy(rsb_cache); +rsb: + kmem_cache_destroy(msg_cache); +msg: + kmem_cache_destroy(lkb_cache); +lkb: + kmem_cache_destroy(mhandle_cache); +mhandle: + kmem_cache_destroy(writequeue_cache); +out: + return -ENOMEM; +} + +void dlm_memory_exit(void) +{ + rcu_barrier(); + + kmem_cache_destroy(writequeue_cache); + kmem_cache_destroy(mhandle_cache); + kmem_cache_destroy(msg_cache); + kmem_cache_destroy(lkb_cache); + kmem_cache_destroy(rsb_cache); + kmem_cache_destroy(cb_cache); +} + +char *dlm_allocate_lvb(struct dlm_ls *ls) +{ + return kzalloc(ls->ls_lvblen, GFP_ATOMIC); +} + +void dlm_free_lvb(char *p) +{ + kfree(p); +} + +struct dlm_rsb *dlm_allocate_rsb(void) +{ + return kmem_cache_zalloc(rsb_cache, GFP_ATOMIC); +} + +static void __free_rsb_rcu(struct rcu_head *rcu) +{ + struct dlm_rsb *r = container_of(rcu, struct dlm_rsb, rcu); + if (r->res_lvbptr) + dlm_free_lvb(r->res_lvbptr); + kmem_cache_free(rsb_cache, r); +} + +void dlm_free_rsb(struct dlm_rsb *r) +{ + call_rcu(&r->rcu, __free_rsb_rcu); +} + +struct dlm_lkb *dlm_allocate_lkb(void) +{ + return kmem_cache_zalloc(lkb_cache, GFP_ATOMIC); +} + +static void __free_lkb_rcu(struct rcu_head *rcu) +{ + struct dlm_lkb *lkb = container_of(rcu, struct dlm_lkb, rcu); + + if (test_bit(DLM_DFL_USER_BIT, &lkb->lkb_dflags)) { + struct dlm_user_args *ua; + ua = lkb->lkb_ua; + if (ua) { + kfree(ua->lksb.sb_lvbptr); + kfree(ua); + } + } + + kmem_cache_free(lkb_cache, lkb); +} + +void dlm_free_lkb(struct dlm_lkb *lkb) +{ + call_rcu(&lkb->rcu, __free_lkb_rcu); +} + +struct dlm_mhandle *dlm_allocate_mhandle(void) +{ + return kmem_cache_alloc(mhandle_cache, GFP_ATOMIC); +} + +void dlm_free_mhandle(struct dlm_mhandle *mhandle) +{ + kmem_cache_free(mhandle_cache, mhandle); +} + +struct writequeue_entry *dlm_allocate_writequeue(void) +{ + return kmem_cache_alloc(writequeue_cache, GFP_ATOMIC); +} + +void dlm_free_writequeue(struct writequeue_entry *writequeue) +{ + kmem_cache_free(writequeue_cache, writequeue); +} + +struct dlm_msg *dlm_allocate_msg(void) +{ + return kmem_cache_alloc(msg_cache, GFP_ATOMIC); +} + +void dlm_free_msg(struct dlm_msg *msg) +{ + kmem_cache_free(msg_cache, msg); +} + +struct dlm_callback *dlm_allocate_cb(void) +{ + return kmem_cache_alloc(cb_cache, GFP_ATOMIC); +} + +void dlm_free_cb(struct dlm_callback *cb) +{ + kmem_cache_free(cb_cache, cb); +} -- cgit v1.3.1