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 --- net/hsr/hsr_debugfs.c | 123 ++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 123 insertions(+) create mode 100644 net/hsr/hsr_debugfs.c (limited to 'net/hsr/hsr_debugfs.c') diff --git a/net/hsr/hsr_debugfs.c b/net/hsr/hsr_debugfs.c new file mode 100644 index 000000000..5b2cfac3b --- /dev/null +++ b/net/hsr/hsr_debugfs.c @@ -0,0 +1,123 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * debugfs code for HSR & PRP + * Copyright (C) 2019 Texas Instruments Incorporated + * + * Author(s): + * Murali Karicheri + */ +#include +#include +#include +#include "hsr_main.h" +#include "hsr_framereg.h" + +static struct dentry *hsr_debugfs_root_dir; + +/* hsr_node_table_show - Formats and prints node_table entries */ +static int +hsr_node_table_show(struct seq_file *sfp, void *data) +{ + struct hsr_priv *priv = (struct hsr_priv *)sfp->private; + struct hsr_node *node; + + seq_printf(sfp, "Node Table entries for (%s) device\n", + (priv->prot_version == PRP_V1 ? "PRP" : "HSR")); + seq_puts(sfp, "MAC-Address-A, MAC-Address-B, time_in[A], "); + seq_puts(sfp, "time_in[B], Address-B port, "); + if (priv->prot_version == PRP_V1) + seq_puts(sfp, "SAN-A, SAN-B, DAN-P\n"); + else + seq_puts(sfp, "DAN-H\n"); + + rcu_read_lock(); + list_for_each_entry_rcu(node, &priv->node_db, mac_list) { + /* skip self node */ + if (hsr_addr_is_self(priv, node->macaddress_A)) + continue; + seq_printf(sfp, "%pM ", &node->macaddress_A[0]); + seq_printf(sfp, "%pM ", &node->macaddress_B[0]); + seq_printf(sfp, "%10lx, ", node->time_in[HSR_PT_SLAVE_A]); + seq_printf(sfp, "%10lx, ", node->time_in[HSR_PT_SLAVE_B]); + seq_printf(sfp, "%14x, ", node->addr_B_port); + + if (priv->prot_version == PRP_V1) + seq_printf(sfp, "%5x, %5x, %5x\n", + node->san_a, node->san_b, + (node->san_a == 0 && node->san_b == 0)); + else + seq_printf(sfp, "%5x\n", 1); + } + rcu_read_unlock(); + return 0; +} + +DEFINE_SHOW_ATTRIBUTE(hsr_node_table); + +void hsr_debugfs_rename(struct net_device *dev) +{ + struct hsr_priv *priv = netdev_priv(dev); + int err; + + err = debugfs_change_name(priv->node_tbl_root, "%s", dev->name); + if (err) + netdev_warn(dev, "failed to rename\n"); +} + +/* hsr_debugfs_init - create hsr node_table file for dumping + * the node table + * + * Description: + * When debugfs is configured this routine sets up the node_table file per + * hsr device for dumping the node_table entries + */ +void hsr_debugfs_init(struct hsr_priv *priv, struct net_device *hsr_dev) +{ + struct dentry *de = NULL; + + de = debugfs_create_dir(hsr_dev->name, hsr_debugfs_root_dir); + if (IS_ERR(de)) { + pr_err("Cannot create hsr debugfs directory\n"); + return; + } + + priv->node_tbl_root = de; + + de = debugfs_create_file("node_table", S_IFREG | 0444, + priv->node_tbl_root, priv, + &hsr_node_table_fops); + if (IS_ERR(de)) { + pr_err("Cannot create hsr node_table file\n"); + debugfs_remove(priv->node_tbl_root); + priv->node_tbl_root = NULL; + return; + } +} + +/* hsr_debugfs_term - Tear down debugfs intrastructure + * + * Description: + * When Debugfs is configured this routine removes debugfs file system + * elements that are specific to hsr + */ +void +hsr_debugfs_term(struct hsr_priv *priv) +{ + debugfs_remove_recursive(priv->node_tbl_root); + priv->node_tbl_root = NULL; +} + +void hsr_debugfs_create_root(void) +{ + hsr_debugfs_root_dir = debugfs_create_dir("hsr", NULL); + if (IS_ERR(hsr_debugfs_root_dir)) { + pr_err("Cannot create hsr debugfs root directory\n"); + hsr_debugfs_root_dir = NULL; + } +} + +void hsr_debugfs_remove_root(void) +{ + /* debugfs_remove() internally checks NULL and ERROR */ + debugfs_remove(hsr_debugfs_root_dir); +} -- cgit v1.3.1