* [PATCH RESEND] kernel: time: posix-timers: Pass lockdep expression to RCU lists
@ 2020-02-16 7:43 Amol Grover
2020-02-17 15:40 ` [tip: timers/core] " tip-bot2 for Amol Grover
2020-02-17 19:18 ` tip-bot2 for Amol Grover
0 siblings, 2 replies; 3+ messages in thread
From: Amol Grover @ 2020-02-16 7:43 UTC (permalink / raw)
To: Thomas Gleixner
Cc: linux-kernel, linux-kernel-mentees, Joel Fernandes,
Madhuparna Bhowmik, Paul E . McKenney, Amol Grover
head is traversed using hlist_for_each_entry_rcu outside an
RCU read-side critical section but under the protection
of hash_lock.
Hence, add corresponding lockdep expression to silence false-positive
lockdep warnings, and harden RCU lists.
Add macro for the corresponding lockdep expression.
Signed-off-by: Amol Grover <frextrite@gmail.com>
---
kernel/time/posix-timers.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)
diff --git a/kernel/time/posix-timers.c b/kernel/time/posix-timers.c
index 0ec5b7a1d769..2ccce00af177 100644
--- a/kernel/time/posix-timers.c
+++ b/kernel/time/posix-timers.c
@@ -50,6 +50,8 @@ static struct kmem_cache *posix_timers_cache;
static DEFINE_HASHTABLE(posix_timers_hashtable, 9);
static DEFINE_SPINLOCK(hash_lock);
+#define hash_lock_held() \
+ lockdep_is_held(&hash_lock)
static const struct k_clock * const posix_clocks[];
static const struct k_clock *clockid_to_kclock(const clockid_t id);
@@ -120,7 +122,7 @@ static struct k_itimer *__posix_timers_find(struct hlist_head *head,
{
struct k_itimer *timer;
- hlist_for_each_entry_rcu(timer, head, t_hash) {
+ hlist_for_each_entry_rcu(timer, head, t_hash, hash_lock_held()) {
if ((timer->it_signal == sig) && (timer->it_id == id))
return timer;
}
--
2.24.1
^ permalink raw reply related [flat|nested] 3+ messages in thread* [tip: timers/core] posix-timers: Pass lockdep expression to RCU lists
2020-02-16 7:43 [PATCH RESEND] kernel: time: posix-timers: Pass lockdep expression to RCU lists Amol Grover
@ 2020-02-17 15:40 ` tip-bot2 for Amol Grover
2020-02-17 19:18 ` tip-bot2 for Amol Grover
1 sibling, 0 replies; 3+ messages in thread
From: tip-bot2 for Amol Grover @ 2020-02-17 15:40 UTC (permalink / raw)
To: linux-tip-commits; +Cc: Amol Grover, Thomas Gleixner, x86, LKML
The following commit has been merged into the timers/core branch of tip:
Commit-ID: 9ea9c60fc23c35f865725ab390ca4308de919bb0
Gitweb: https://git.kernel.org/tip/9ea9c60fc23c35f865725ab390ca4308de919bb0
Author: Amol Grover <frextrite@gmail.com>
AuthorDate: Sun, 16 Feb 2020 13:13:30 +05:30
Committer: Thomas Gleixner <tglx@linutronix.de>
CommitterDate: Mon, 17 Feb 2020 16:39:28 +01:00
posix-timers: Pass lockdep expression to RCU lists
head is traversed using hlist_for_each_entry_rcu outside an RCU read-side
critical section but under the protection of hash_lock.
Hence, add corresponding lockdep expression to silence false-positive
lockdep warnings, and harden RCU lists.
[ tglx: Removed the macro and put the condition right where it's used ]
Signed-off-by: Amol Grover <frextrite@gmail.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lkml.kernel.org/r/20200216074330.GA14025@workstation-portable
---
kernel/time/posix-timers.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/kernel/time/posix-timers.c b/kernel/time/posix-timers.c
index ff0eb30..07709ac 100644
--- a/kernel/time/posix-timers.c
+++ b/kernel/time/posix-timers.c
@@ -121,7 +121,8 @@ static struct k_itimer *__posix_timers_find(struct hlist_head *head,
{
struct k_itimer *timer;
- hlist_for_each_entry_rcu(timer, head, t_hash) {
+ hlist_for_each_entry_rcu(timer, head, t_hash,
+ lockdep_is_held(&hash_lock)) {
if ((timer->it_signal == sig) && (timer->it_id == id))
return timer;
}
^ permalink raw reply related [flat|nested] 3+ messages in thread* [tip: timers/core] posix-timers: Pass lockdep expression to RCU lists
2020-02-16 7:43 [PATCH RESEND] kernel: time: posix-timers: Pass lockdep expression to RCU lists Amol Grover
2020-02-17 15:40 ` [tip: timers/core] " tip-bot2 for Amol Grover
@ 2020-02-17 19:18 ` tip-bot2 for Amol Grover
1 sibling, 0 replies; 3+ messages in thread
From: tip-bot2 for Amol Grover @ 2020-02-17 19:18 UTC (permalink / raw)
To: linux-tip-commits; +Cc: Amol Grover, Thomas Gleixner, x86, LKML
The following commit has been merged into the timers/core branch of tip:
Commit-ID: 5fb1c2a5bbf79ccca8d17cf97f66085be5808027
Gitweb: https://git.kernel.org/tip/5fb1c2a5bbf79ccca8d17cf97f66085be5808027
Author: Amol Grover <frextrite@gmail.com>
AuthorDate: Sun, 16 Feb 2020 13:13:30 +05:30
Committer: Thomas Gleixner <tglx@linutronix.de>
CommitterDate: Mon, 17 Feb 2020 20:12:19 +01:00
posix-timers: Pass lockdep expression to RCU lists
head is traversed using hlist_for_each_entry_rcu outside an RCU read-side
critical section but under the protection of hash_lock.
Hence, add corresponding lockdep expression to silence false-positive
lockdep warnings, and harden RCU lists.
[ tglx: Removed the macro and put the condition right where it's used ]
Signed-off-by: Amol Grover <frextrite@gmail.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lkml.kernel.org/r/20200216074330.GA14025@workstation-portable
---
kernel/time/posix-timers.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/kernel/time/posix-timers.c b/kernel/time/posix-timers.c
index ff0eb30..07709ac 100644
--- a/kernel/time/posix-timers.c
+++ b/kernel/time/posix-timers.c
@@ -121,7 +121,8 @@ static struct k_itimer *__posix_timers_find(struct hlist_head *head,
{
struct k_itimer *timer;
- hlist_for_each_entry_rcu(timer, head, t_hash) {
+ hlist_for_each_entry_rcu(timer, head, t_hash,
+ lockdep_is_held(&hash_lock)) {
if ((timer->it_signal == sig) && (timer->it_id == id))
return timer;
}
^ permalink raw reply related [flat|nested] 3+ messages in thread
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