diff options
Diffstat (limited to 'debian/patches-rt/0024-kmemleak-Turn-kmemleak_lock-to-raw-spinlock-on-RT.patch')
| -rw-r--r-- | debian/patches-rt/0024-kmemleak-Turn-kmemleak_lock-to-raw-spinlock-on-RT.patch | 169 |
1 files changed, 169 insertions, 0 deletions
diff --git a/debian/patches-rt/0024-kmemleak-Turn-kmemleak_lock-to-raw-spinlock-on-RT.patch b/debian/patches-rt/0024-kmemleak-Turn-kmemleak_lock-to-raw-spinlock-on-RT.patch new file mode 100644 index 000000000..13c6dabe9 --- /dev/null +++ b/debian/patches-rt/0024-kmemleak-Turn-kmemleak_lock-to-raw-spinlock-on-RT.patch @@ -0,0 +1,169 @@ +From 4de935e0bd7598a837928fb0d15048e5b04c5b05 Mon Sep 17 00:00:00 2001 +From: He Zhe <zhe.he@windriver.com> +Date: Wed, 19 Dec 2018 16:30:57 +0100 +Subject: [PATCH 024/347] kmemleak: Turn kmemleak_lock to raw spinlock on RT +MIME-Version: 1.0 +Content-Type: text/plain; charset=UTF-8 +Content-Transfer-Encoding: 8bit +Origin: https://www.kernel.org/pub/linux/kernel/projects/rt/4.19/older/patches-4.19.246-rt110.tar.xz + +kmemleak_lock, as a rwlock on RT, can possibly be held in atomic context and +causes the follow BUG. + +BUG: scheduling while atomic: migration/15/132/0x00000002 +Preemption disabled at: +[<ffffffff8c927c11>] cpu_stopper_thread+0x71/0x100 +CPU: 15 PID: 132 Comm: migration/15 Not tainted 4.19.0-rt1-preempt-rt #1 +Call Trace: + schedule+0x3d/0xe0 + __rt_spin_lock+0x26/0x30 + __write_rt_lock+0x23/0x1a0 + rt_write_lock+0x2a/0x30 + find_and_remove_object+0x1e/0x80 + delete_object_full+0x10/0x20 + kmemleak_free+0x32/0x50 + kfree+0x104/0x1f0 + intel_pmu_cpu_dying+0x67/0x70 + x86_pmu_dying_cpu+0x1a/0x30 + cpuhp_invoke_callback+0x92/0x700 + take_cpu_down+0x70/0xa0 + multi_cpu_stop+0x62/0xc0 + cpu_stopper_thread+0x79/0x100 + smpboot_thread_fn+0x20f/0x2d0 + kthread+0x121/0x140 + +And on v4.18 stable tree the following call trace, caused by grabbing +kmemleak_lock again, is also observed. + +kernel BUG at kernel/locking/rtmutex.c:1048! +CPU: 5 PID: 689 Comm: mkfs.ext4 Not tainted 4.18.16-rt9-preempt-rt #1 +Call Trace: + rt_write_lock+0x2a/0x30 + create_object+0x17d/0x2b0 + kmemleak_alloc+0x34/0x50 + kmem_cache_alloc+0x146/0x220 + mempool_alloc_slab+0x15/0x20 + mempool_alloc+0x65/0x170 + sg_pool_alloc+0x21/0x60 + sg_alloc_table_chained+0x8b/0xb0 +… + blk_flush_plug_list+0x204/0x230 + schedule+0x87/0xe0 + rt_write_lock+0x2a/0x30 + create_object+0x17d/0x2b0 + kmemleak_alloc+0x34/0x50 + __kmalloc_node+0x1cd/0x340 + alloc_request_size+0x30/0x70 + mempool_alloc+0x65/0x170 + get_request+0x4e3/0x8d0 + blk_queue_bio+0x153/0x470 + generic_make_request+0x1dc/0x3f0 + submit_bio+0x49/0x140 +… + +kmemleak is an error detecting feature. We would not expect as good performance +as without it. As there is no raw rwlock defining helpers, we turn kmemleak_lock +to a raw spinlock. + +Signed-off-by: He Zhe <zhe.he@windriver.com> +Cc: catalin.marinas@arm.com +Cc: bigeasy@linutronix.de +Cc: tglx@linutronix.de +Cc: rostedt@goodmis.org +Acked-by: Catalin Marinas <catalin.marinas@arm.com> +Link: https://lkml.kernel.org/r/1542877459-144382-1-git-send-email-zhe.he@windriver.com +Link: https://lkml.kernel.org/r/20181218150744.GB20197@arrakis.emea.arm.com +Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> +--- + mm/kmemleak.c | 20 ++++++++++---------- + 1 file changed, 10 insertions(+), 10 deletions(-) + +diff --git a/mm/kmemleak.c b/mm/kmemleak.c +index 639acbb91fd5..5b6718dd3a64 100644 +--- a/mm/kmemleak.c ++++ b/mm/kmemleak.c +@@ -26,7 +26,7 @@ + * + * The following locks and mutexes are used by kmemleak: + * +- * - kmemleak_lock (rwlock): protects the object_list modifications and ++ * - kmemleak_lock (raw spinlock): protects the object_list modifications and + * accesses to the object_tree_root. The object_list is the main list + * holding the metadata (struct kmemleak_object) for the allocated memory + * blocks. The object_tree_root is a red black tree used to look-up +@@ -197,7 +197,7 @@ static LIST_HEAD(gray_list); + /* search tree for object boundaries */ + static struct rb_root object_tree_root = RB_ROOT; + /* rw_lock protecting the access to object_list and object_tree_root */ +-static DEFINE_RWLOCK(kmemleak_lock); ++static DEFINE_RAW_SPINLOCK(kmemleak_lock); + + /* allocation caches for kmemleak internal data */ + static struct kmem_cache *object_cache; +@@ -491,9 +491,9 @@ static struct kmemleak_object *find_and_get_object(unsigned long ptr, int alias) + struct kmemleak_object *object; + + rcu_read_lock(); +- read_lock_irqsave(&kmemleak_lock, flags); ++ raw_spin_lock_irqsave(&kmemleak_lock, flags); + object = lookup_object(ptr, alias); +- read_unlock_irqrestore(&kmemleak_lock, flags); ++ raw_spin_unlock_irqrestore(&kmemleak_lock, flags); + + /* check whether the object is still available */ + if (object && !get_object(object)) +@@ -513,13 +513,13 @@ static struct kmemleak_object *find_and_remove_object(unsigned long ptr, int ali + unsigned long flags; + struct kmemleak_object *object; + +- write_lock_irqsave(&kmemleak_lock, flags); ++ raw_spin_lock_irqsave(&kmemleak_lock, flags); + object = lookup_object(ptr, alias); + if (object) { + rb_erase(&object->rb_node, &object_tree_root); + list_del_rcu(&object->object_list); + } +- write_unlock_irqrestore(&kmemleak_lock, flags); ++ raw_spin_unlock_irqrestore(&kmemleak_lock, flags); + + return object; + } +@@ -593,7 +593,7 @@ static struct kmemleak_object *create_object(unsigned long ptr, size_t size, + /* kernel backtrace */ + object->trace_len = __save_stack_trace(object->trace); + +- write_lock_irqsave(&kmemleak_lock, flags); ++ raw_spin_lock_irqsave(&kmemleak_lock, flags); + + min_addr = min(min_addr, ptr); + max_addr = max(max_addr, ptr + size); +@@ -624,7 +624,7 @@ static struct kmemleak_object *create_object(unsigned long ptr, size_t size, + + list_add_tail_rcu(&object->object_list, &object_list); + out: +- write_unlock_irqrestore(&kmemleak_lock, flags); ++ raw_spin_unlock_irqrestore(&kmemleak_lock, flags); + return object; + } + +@@ -1310,7 +1310,7 @@ static void scan_block(void *_start, void *_end, + unsigned long *end = _end - (BYTES_PER_POINTER - 1); + unsigned long flags; + +- read_lock_irqsave(&kmemleak_lock, flags); ++ raw_spin_lock_irqsave(&kmemleak_lock, flags); + for (ptr = start; ptr < end; ptr++) { + struct kmemleak_object *object; + unsigned long pointer; +@@ -1367,7 +1367,7 @@ static void scan_block(void *_start, void *_end, + spin_unlock(&object->lock); + } + } +- read_unlock_irqrestore(&kmemleak_lock, flags); ++ raw_spin_unlock_irqrestore(&kmemleak_lock, flags); + } + + /* +-- +2.36.1 + |