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drivers: char: ipmi: ipmi_msghandler: Pass lockdep expression to RCU lists

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intf->cmd_rcvrs is traversed with list_for_each_entry_rcu
outside an RCU read-side critical section but under the
protection of intf->cmd_rcvrs_mutex.

ipmi_interfaces is traversed using list_for_each_entry_rcu
outside an RCU read-side critical section but under the protection
of ipmi_interfaces_mutex.

Hence, add the corresponding lockdep expression to the list traversal
primitive to silence false-positive lockdep warnings, and
harden RCU lists.

Add macro for the corresponding lockdep expression to make the code
clean and concise.

Signed-off-by: Amol Grover <frextrite@gmail.com>
Message-Id: <20200117132521.31020-1-frextrite@gmail.com>
Acked-by: Paul E. McKenney <paulmck@kernel.org>
Tested-by: John Garry <john.garry@huawei.com>
Signed-off-by: Corey Minyard <cminyard@mvista.com>
This commit is contained in:
Amol Grover 2020-01-17 18:55:22 +05:30 committed by Corey Minyard
parent 3cc6e2c599
commit 4f1885a7b3
1 changed files with 10 additions and 4 deletions
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14
drivers/char/ipmi/ipmi_msghandler.c
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@ -618,6 +618,8 @@ static DEFINE_MUTEX(ipmidriver_mutex);
static LIST_HEAD(ipmi_interfaces);
static DEFINE_MUTEX(ipmi_interfaces_mutex);
#define ipmi_interfaces_mutex_held() \
lockdep_is_held(&ipmi_interfaces_mutex)
static struct srcu_struct ipmi_interfaces_srcu;
/*
@ -1321,7 +1323,8 @@ static void _ipmi_destroy_user(struct ipmi_user *user)
* synchronize_srcu()) then free everything in that list.
*/
mutex_lock(&intf->cmd_rcvrs_mutex);
list_for_each_entry_rcu(rcvr, &intf->cmd_rcvrs, link) {
list_for_each_entry_rcu(rcvr, &intf->cmd_rcvrs, link,
lockdep_is_held(&intf->cmd_rcvrs_mutex)) {
if (rcvr->user == user) {
list_del_rcu(&rcvr->link);
rcvr->next = rcvrs;
@ -1599,7 +1602,8 @@ static struct cmd_rcvr *find_cmd_rcvr(struct ipmi_smi *intf,
{
struct cmd_rcvr *rcvr;
list_for_each_entry_rcu(rcvr, &intf->cmd_rcvrs, link) {
list_for_each_entry_rcu(rcvr, &intf->cmd_rcvrs, link,
lockdep_is_held(&intf->cmd_rcvrs_mutex)) {
if ((rcvr->netfn == netfn) && (rcvr->cmd == cmd)
&& (rcvr->chans & (1 << chan)))
return rcvr;
@ -1614,7 +1618,8 @@ static int is_cmd_rcvr_exclusive(struct ipmi_smi *intf,
{
struct cmd_rcvr *rcvr;
list_for_each_entry_rcu(rcvr, &intf->cmd_rcvrs, link) {
list_for_each_entry_rcu(rcvr, &intf->cmd_rcvrs, link,
lockdep_is_held(&intf->cmd_rcvrs_mutex)) {
if ((rcvr->netfn == netfn) && (rcvr->cmd == cmd)
&& (rcvr->chans & chans))
return 0;
@ -3450,7 +3455,8 @@ int ipmi_add_smi(struct module *owner,
/* Look for a hole in the numbers. */
i = 0;
link = &ipmi_interfaces;
list_for_each_entry_rcu(tintf, &ipmi_interfaces, link) {
list_for_each_entry_rcu(tintf, &ipmi_interfaces, link,
ipmi_interfaces_mutex_held()) {
if (tintf->intf_num != i) {
link = &tintf->link;
break;