On Tue, 11 Feb 2025 11:39:49 +0000 Tvrtko Ursulin <tursulin@xxxxxxxxxxx> wrote: > On 10/02/2025 16:08, Adrián Larumbe wrote: > > Hi Tvrtko, > > Thanks! > > > [18153.770244] BUG: sleeping function called from invalid context at kernel/locking/mutex.c:562 > > [18153.771059] in_atomic(): 1, irqs_disabled(): 0, non_block: 0, pid: 203412, name: cat > > [18153.771757] preempt_count: 1, expected: 0 > > [18153.772164] RCU nest depth: 0, expected: 0 > > [18153.772538] INFO: lockdep is turned off. > > [18153.772898] CPU: 4 UID: 0 PID: 203412 Comm: cat Tainted: G W 6.14.0-rc1-panthor-next-rk3588-fdinfo+ #1 > > [18153.772906] Tainted: [W]=WARN > > [18153.772908] Hardware name: Radxa ROCK 5B (DT) > > [18153.772911] Call trace: > > [18153.772913] show_stack+0x24/0x38 (C) > > [18153.772927] dump_stack_lvl+0x3c/0x98 > > [18153.772935] dump_stack+0x18/0x24 > > [18153.772941] __might_resched+0x298/0x2b0 > > [18153.772948] __might_sleep+0x6c/0xb0 > > [18153.772953] __mutex_lock_common+0x7c/0x1950 > > [18153.772962] mutex_lock_nested+0x38/0x50 > > [18153.772969] panthor_fdinfo_gather_group_samples+0x80/0x138 [panthor] > > [18153.773042] panthor_show_fdinfo+0x80/0x228 [panthor] > > [18153.773109] drm_show_fdinfo+0x1a4/0x1e0 [drm] > > [18153.773397] seq_show+0x274/0x358 > > [18153.773404] seq_read_iter+0x1d4/0x630 > > There is a mutex_lock literally in seq_read_iter. > > So colour me confused. What created the atomic context between then and > Panthor code?! I just don't see it. It's actually the xa_lock() we take when gathering fdinfo data that puts us in this atomic context. In other words, the fix is correct, but the explanation is wrong :-).
