[PATCH 4.9 236/240] lib: stackdepot: turn depot_lock spinlock to raw_spinlock

Greg Kroah-Hartman
2021-05-20T11:24:41Z

From: Zqiang <qiang.zhang@windriver.com>

[ 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@windriver.com
Signed-off-by: Zqiang <qiang.zhang@windriver.com>
Reported-by: Andrew Halaney <ahalaney@redhat.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Gustavo A. R. Silva <gustavoars@kernel.org>
Cc: Vijayanand Jitta <vjitta@codeaurora.org>
Cc: Vinayak Menon <vinmenon@codeaurora.org>
Cc: Yogesh Lal <ylal@codeaurora.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
lib/stackdepot.c | 6 +++---
1 file changed, 3 insertions(+), 3 deletions(-)

--- a/lib/stackdepot.c
+++ b/lib/stackdepot.c
@@ -78,7 +78,7 @@ static void *stack_slabs[STACK_ALLOC_MAX
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)
{
@@ -253,7 +253,7 @@ depot_stack_handle_t depot_save_stack(st
prealloc = page_address(page);
}

- spin_lock_irqsave(&depot_lock, flags);
+ raw_spin_lock_irqsave(&depot_lock, flags);

found = find_stack(*bucket, trace->entries, trace->nr_entries, hash);
if (!found) {
@@ -277,7 +277,7 @@ depot_stack_handle_t depot_save_stack(st
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. */