This is a note to let you know that I've just added the patch titled lib: stackdepot: turn depot_lock spinlock to raw_spinlock to the 5.4-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: lib-stackdepot-turn-depot_lock-spinlock-to-raw_spinl.patch and it can be found in the queue-5.4 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. commit 5d30a1a418a196dd50059cc1e6e48d3c1cbfc6d2 Author: Zqiang <qiang.zhang@xxxxxxxxxxxxx> Date: Thu May 6 18:03:40 2021 -0700 lib: stackdepot: turn depot_lock spinlock to raw_spinlock [ Upstream commit 78564b9434878d686c5f88c4488b20cccbcc42bc ] In RT system, the spin_lock will be replaced by sleepable rt_mutex lock, in __call_rcu(), disable interrupts before calling kasan_record_aux_stack(), will trigger this calltrace: BUG: sleeping function called from invalid context at kernel/locking/rtmutex.c:951 in_atomic(): 0, irqs_disabled(): 1, non_block: 0, pid: 19, name: pgdatinit0 Call Trace: ___might_sleep.cold+0x1b2/0x1f1 rt_spin_lock+0x3b/0xb0 stack_depot_save+0x1b9/0x440 kasan_save_stack+0x32/0x40 kasan_record_aux_stack+0xa5/0xb0 __call_rcu+0x117/0x880 __exit_signal+0xafb/0x1180 release_task+0x1d6/0x480 exit_notify+0x303/0x750 do_exit+0x678/0xcf0 kthread+0x364/0x4f0 ret_from_fork+0x22/0x30 Replace spinlock with raw_spinlock. Link: https://lkml.kernel.org/r/20210329084009.27013-1-qiang.zhang@xxxxxxxxxxxxx Signed-off-by: Zqiang <qiang.zhang@xxxxxxxxxxxxx> Reported-by: Andrew Halaney <ahalaney@xxxxxxxxxx> Cc: Alexander Potapenko <glider@xxxxxxxxxx> Cc: Gustavo A. R. Silva <gustavoars@xxxxxxxxxx> Cc: Vijayanand Jitta <vjitta@xxxxxxxxxxxxxx> Cc: Vinayak Menon <vinmenon@xxxxxxxxxxxxxx> Cc: Yogesh Lal <ylal@xxxxxxxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> Signed-off-by: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> diff --git a/lib/stackdepot.c b/lib/stackdepot.c index 81c69c08d1d1..468626b8eb1b 100644 --- a/lib/stackdepot.c +++ b/lib/stackdepot.c @@ -69,7 +69,7 @@ static void *stack_slabs[STACK_ALLOC_MAX_SLABS]; static int depot_index; static int next_slab_inited; static size_t depot_offset; -static DEFINE_SPINLOCK(depot_lock); +static DEFINE_RAW_SPINLOCK(depot_lock); static bool init_stack_slab(void **prealloc) { @@ -269,7 +269,7 @@ depot_stack_handle_t stack_depot_save(unsigned long *entries, prealloc = page_address(page); } - spin_lock_irqsave(&depot_lock, flags); + raw_spin_lock_irqsave(&depot_lock, flags); found = find_stack(*bucket, entries, nr_entries, hash); if (!found) { @@ -293,7 +293,7 @@ depot_stack_handle_t stack_depot_save(unsigned long *entries, WARN_ON(!init_stack_slab(&prealloc)); } - spin_unlock_irqrestore(&depot_lock, flags); + raw_spin_unlock_irqrestore(&depot_lock, flags); exit: if (prealloc) { /* Nobody used this memory, ok to free it. */