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author | Thomas Gleixner | 2020-07-29 10:53:28 +0200 |
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committer | Ingo Molnar | 2020-07-29 16:27:16 +0200 |
commit | bdd65589593edd79b6a12ce86b3b7a7c6dae5208 (patch) | |
tree | fa9b59260020434dace3e71beda74a527c6de7b8 /Makefile | |
parent | 92ed301919932f777713b9172e525674157e983d (diff) |
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 <lkp@intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/87365abt2v.fsf@nanos.tec.linutronix.de
Diffstat (limited to 'Makefile')
0 files changed, 0 insertions, 0 deletions