diff options
Diffstat (limited to 'debian/patches-rt/0022-mm-kasan-make-quarantine_lock-a-raw_spinlock_t.patch')
| -rw-r--r-- | debian/patches-rt/0022-mm-kasan-make-quarantine_lock-a-raw_spinlock_t.patch | 98 |
1 files changed, 98 insertions, 0 deletions
diff --git a/debian/patches-rt/0022-mm-kasan-make-quarantine_lock-a-raw_spinlock_t.patch b/debian/patches-rt/0022-mm-kasan-make-quarantine_lock-a-raw_spinlock_t.patch new file mode 100644 index 000000000..0d6a6458f --- /dev/null +++ b/debian/patches-rt/0022-mm-kasan-make-quarantine_lock-a-raw_spinlock_t.patch @@ -0,0 +1,98 @@ +From 4613446aa7e0744f1f4895714184b4a5608153bd Mon Sep 17 00:00:00 2001 +From: Clark Williams <williams@redhat.com> +Date: Tue, 18 Sep 2018 10:29:31 -0500 +Subject: [PATCH 022/347] mm/kasan: make quarantine_lock a raw_spinlock_t +Origin: https://www.kernel.org/pub/linux/kernel/projects/rt/4.19/older/patches-4.19.246-rt110.tar.xz + +The static lock quarantine_lock is used in quarantine.c to protect the +quarantine queue datastructures. It is taken inside quarantine queue +manipulation routines (quarantine_put(), quarantine_reduce() and +quarantine_remove_cache()), with IRQs disabled. +This is not a problem on a stock kernel but is problematic on an RT +kernel where spin locks are sleeping spinlocks, which can sleep and can +not be acquired with disabled interrupts. + +Convert the quarantine_lock to a raw spinlock_t. The usage of +quarantine_lock is confined to quarantine.c and the work performed while +the lock is held is limited. + +Signed-off-by: Clark Williams <williams@redhat.com> +Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> +--- + mm/kasan/quarantine.c | 18 +++++++++--------- + 1 file changed, 9 insertions(+), 9 deletions(-) + +diff --git a/mm/kasan/quarantine.c b/mm/kasan/quarantine.c +index 3a8ddf8baf7d..b209dbaefde8 100644 +--- a/mm/kasan/quarantine.c ++++ b/mm/kasan/quarantine.c +@@ -103,7 +103,7 @@ static int quarantine_head; + static int quarantine_tail; + /* Total size of all objects in global_quarantine across all batches. */ + static unsigned long quarantine_size; +-static DEFINE_SPINLOCK(quarantine_lock); ++static DEFINE_RAW_SPINLOCK(quarantine_lock); + DEFINE_STATIC_SRCU(remove_cache_srcu); + + /* Maximum size of the global queue. */ +@@ -190,7 +190,7 @@ void quarantine_put(struct kasan_free_meta *info, struct kmem_cache *cache) + if (unlikely(q->bytes > QUARANTINE_PERCPU_SIZE)) { + qlist_move_all(q, &temp); + +- spin_lock(&quarantine_lock); ++ raw_spin_lock(&quarantine_lock); + WRITE_ONCE(quarantine_size, quarantine_size + temp.bytes); + qlist_move_all(&temp, &global_quarantine[quarantine_tail]); + if (global_quarantine[quarantine_tail].bytes >= +@@ -203,7 +203,7 @@ void quarantine_put(struct kasan_free_meta *info, struct kmem_cache *cache) + if (new_tail != quarantine_head) + quarantine_tail = new_tail; + } +- spin_unlock(&quarantine_lock); ++ raw_spin_unlock(&quarantine_lock); + } + + local_irq_restore(flags); +@@ -230,7 +230,7 @@ void quarantine_reduce(void) + * expected case). + */ + srcu_idx = srcu_read_lock(&remove_cache_srcu); +- spin_lock_irqsave(&quarantine_lock, flags); ++ raw_spin_lock_irqsave(&quarantine_lock, flags); + + /* + * Update quarantine size in case of hotplug. Allocate a fraction of +@@ -254,7 +254,7 @@ void quarantine_reduce(void) + quarantine_head = 0; + } + +- spin_unlock_irqrestore(&quarantine_lock, flags); ++ raw_spin_unlock_irqrestore(&quarantine_lock, flags); + + qlist_free_all(&to_free, NULL); + srcu_read_unlock(&remove_cache_srcu, srcu_idx); +@@ -310,17 +310,17 @@ void quarantine_remove_cache(struct kmem_cache *cache) + */ + on_each_cpu(per_cpu_remove_cache, cache, 1); + +- spin_lock_irqsave(&quarantine_lock, flags); ++ raw_spin_lock_irqsave(&quarantine_lock, flags); + for (i = 0; i < QUARANTINE_BATCHES; i++) { + if (qlist_empty(&global_quarantine[i])) + continue; + qlist_move_cache(&global_quarantine[i], &to_free, cache); + /* Scanning whole quarantine can take a while. */ +- spin_unlock_irqrestore(&quarantine_lock, flags); ++ raw_spin_unlock_irqrestore(&quarantine_lock, flags); + cond_resched(); +- spin_lock_irqsave(&quarantine_lock, flags); ++ raw_spin_lock_irqsave(&quarantine_lock, flags); + } +- spin_unlock_irqrestore(&quarantine_lock, flags); ++ raw_spin_unlock_irqrestore(&quarantine_lock, flags); + + qlist_free_all(&to_free, cache); + +-- +2.36.1 + |