The exit_pi_state_list() function calls put_pi_state() with IRQs
disabled and is not expecting that IRQs will be enabled inside the
function. Use the _irqsave() so that IRQs are restored to the original
state instead of enabled unconditionally.
Fixes: 153fbd1226fb ("futex: Fix more put_pi_state() vs. exit_pi_state_list() races")
Signed-off-by: Dan Carpenter <dan.carpenter@xxxxxxxxxx>
---
This is from static analysis and not tested. I am not very familiar
with futex code.
kernel/futex.c | 5 +++--
1 file changed, 3 insertions(+), 2 deletions(-)
diff --git a/kernel/futex.c b/kernel/futex.c
index f8614ef4ff31..ca84745713bc 100644
--- a/kernel/futex.c
+++ b/kernel/futex.c
@@ -788,8 +788,9 @@ static void put_pi_state(struct futex_pi_state *pi_state)
*/
if (pi_state->owner) {
struct task_struct *owner;
+ unsigned long flags;
- raw_spin_lock_irq(&pi_state->pi_mutex.wait_lock);
+ raw_spin_lock_irqsave(&pi_state->pi_mutex.wait_lock, flags);
owner = pi_state->owner;
if (owner) {
raw_spin_lock(&owner->pi_lock);
@@ -797,7 +798,7 @@ static void put_pi_state(struct futex_pi_state *pi_state)
raw_spin_unlock(&owner->pi_lock);
}
rt_mutex_proxy_unlock(&pi_state->pi_mutex, owner);
- raw_spin_unlock_irq(&pi_state->pi_mutex.wait_lock);
+ raw_spin_unlock_irqrestore(&pi_state->pi_mutex.wait_lock, flags);
}
if (current->pi_state_cache) {
--
2.28.0
