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authorQinglang Miao <miaoqinglang@huawei.com>2020-11-19 10:08:39 +0300
committerCorey Minyard <cminyard@mvista.com>2020-11-19 15:36:28 +0300
commit368ffd9adc7a01234c0c68ffd72cc76840f20134 (patch)
treedcdb4da651360e9fc5f58a75087537b451b74a4d /drivers/char
parenta01a89b1db1066a6af23ae08b9a0c345b7966f0b (diff)
downloadlinux-368ffd9adc7a01234c0c68ffd72cc76840f20134.tar.xz
ipmi: msghandler: Suppress suspicious RCU usage warning
while running ipmi, ipmi_smi_watcher_register() caused a suspicious RCU usage warning. ----- ============================= WARNING: suspicious RCU usage 5.10.0-rc3+ #1 Not tainted ----------------------------- drivers/char/ipmi/ipmi_msghandler.c:750 RCU-list traversed in non-reader section!! other info that might help us debug this: rcu_scheduler_active = 2, debug_locks = 1 2 locks held by syz-executor.0/4254: stack backtrace: CPU: 0 PID: 4254 Comm: syz-executor.0 Not tainted 5.10.0-rc3+ #1 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.13.0-1ubuntu1 04/ 01/2014 Call Trace: dump_stack+0x19d/0x200 ipmi_smi_watcher_register+0x2d3/0x340 [ipmi_msghandler] acpi_ipmi_init+0xb1/0x1000 [acpi_ipmi] do_one_initcall+0x149/0x7e0 do_init_module+0x1ef/0x700 load_module+0x3467/0x4140 __do_sys_finit_module+0x10d/0x1a0 do_syscall_64+0x34/0x80 entry_SYSCALL_64_after_hwframe+0x44/0xa9 RIP: 0033:0x468ded ----- It is safe because smi_watchers_mutex is locked and srcu_read_lock has been used, so simply pass lockdep_is_held() to the list_for_each_entry_rcu() to suppress this warning. Reported-by: Hulk Robot <hulkci@huawei.com> Signed-off-by: Qinglang Miao <miaoqinglang@huawei.com> Message-Id: <20201119070839.381-1-miaoqinglang@huawei.com> Signed-off-by: Corey Minyard <cminyard@mvista.com>
Diffstat (limited to 'drivers/char')
-rw-r--r--drivers/char/ipmi/ipmi_msghandler.c3
1 files changed, 2 insertions, 1 deletions
diff --git a/drivers/char/ipmi/ipmi_msghandler.c b/drivers/char/ipmi/ipmi_msghandler.c
index 8774a3b8ff95..c44ad18464f1 100644
--- a/drivers/char/ipmi/ipmi_msghandler.c
+++ b/drivers/char/ipmi/ipmi_msghandler.c
@@ -747,7 +747,8 @@ int ipmi_smi_watcher_register(struct ipmi_smi_watcher *watcher)
list_add(&watcher->link, &smi_watchers);
index = srcu_read_lock(&ipmi_interfaces_srcu);
- list_for_each_entry_rcu(intf, &ipmi_interfaces, link) {
+ list_for_each_entry_rcu(intf, &ipmi_interfaces, link,
+ lockdep_is_held(&smi_watchers_mutex)) {
int intf_num = READ_ONCE(intf->intf_num);
if (intf_num == -1)