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Chengfeng Ye
67288cbb7a
[ Upstream commit 2f19c4b839 ]
handle_receive_interrupt_napi_sp() running inside interrupt handler
could introduce inverse lock ordering between &dd->irq_src_lock
and &dd->uctxt_lock, if read_mod_write() is preempted by the isr.
[CPU0] | [CPU1]
hfi1_ipoib_dev_open() |
--> hfi1_netdev_enable_queues() |
--> enable_queues(rx) |
--> hfi1_rcvctrl() |
--> set_intr_bits() |
--> read_mod_write() |
--> spin_lock(&dd->irq_src_lock) |
| hfi1_poll()
| --> poll_next()
| --> spin_lock_irq(&dd->uctxt_lock)
|
| --> hfi1_rcvctrl()
| --> set_intr_bits()
| --> read_mod_write()
| --> spin_lock(&dd->irq_src_lock)
<interrupt> |
--> handle_receive_interrupt_napi_sp() |
--> set_all_fastpath() |
--> hfi1_rcd_get_by_index() |
--> spin_lock_irqsave(&dd->uctxt_lock) |
This flaw was found by an experimental static analysis tool I am
developing for irq-related deadlock.
To prevent the potential deadlock, the patch use spin_lock_irqsave()
on &dd->irq_src_lock inside read_mod_write() to prevent the possible
deadlock scenario.
Signed-off-by: Chengfeng Ye <dg573847474@gmail.com>
Link: https://lore.kernel.org/r/20230926101116.2797-1-dg573847474@gmail.com
Acked-by: Dennis Dalessandro <dennis.dalessandro@cornelisnetworks.com>
Signed-off-by: Leon Romanovsky <leon@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Linux kernel
============
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There are various text files in the Documentation/ subdirectory,
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Please read the Documentation/process/changes.rst file, as it contains the
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