diff options
| author | Thomas Gleixner <[email protected]> | 2020-07-29 08:53:28 +0000 |
|---|---|---|
| committer | Ingo Molnar <[email protected]> | 2020-07-29 14:27:16 +0000 |
| commit | bdd65589593edd79b6a12ce86b3b7a7c6dae5208 (patch) | |
| tree | fa9b59260020434dace3e71beda74a527c6de7b8 /drivers/gpu/drm/lima/lima_gem.c | |
| parent | Linux 5.8-rc7 (diff) | |
| download | kernel-bdd65589593edd79b6a12ce86b3b7a7c6dae5208.tar.gz kernel-bdd65589593edd79b6a12ce86b3b7a7c6dae5208.zip | |
x86/i8259: Use printk_deferred() to prevent deadlock
0day reported a possible circular locking dependency:
Chain exists of:
&irq_desc_lock_class --> console_owner --> &port_lock_key
Possible unsafe locking scenario:
CPU0 CPU1
---- ----
lock(&port_lock_key);
lock(console_owner);
lock(&port_lock_key);
lock(&irq_desc_lock_class);
The reason for this is a printk() in the i8259 interrupt chip driver
which is invoked with the irq descriptor lock held, which reverses the
lock operations vs. printk() from arbitrary contexts.
Switch the printk() to printk_deferred() to avoid that.
Reported-by: kernel test robot <[email protected]>
Signed-off-by: Thomas Gleixner <[email protected]>
Signed-off-by: Ingo Molnar <[email protected]>
Cc: [email protected]
Link: https://lore.kernel.org/r/[email protected]
Diffstat (limited to 'drivers/gpu/drm/lima/lima_gem.c')
0 files changed, 0 insertions, 0 deletions
