uio: uio_dmem_genirq: Fix deadlock between irq config and handling

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This fixes a concurrency issue addressed in commit 34cb275283 ("UIO: Fix
concurrency issue"):

  "In a SMP case there was a race condition issue between
  Uio_pdrv_genirq_irqcontrol() running on one CPU and irq handler on
  another CPU. Fix it by spin_locking shared resources access inside irq
  handler."

The implementation of "uio_dmem_genirq" was based on "uio_pdrv_genirq" and
it is used in a similar manner to the "uio_pdrv_genirq" driver with respect
to interrupt configuration and handling. At the time "uio_dmem_genirq" was
merged, both had the same implementation of the 'uio_info' handlers
irqcontrol() and handler(), thus, both had the same concurrency issue
mentioned by the above commit. However, the above patch was only applied to
the "uio_pdrv_genirq" driver.

Split out from commit 34cb275283 ("UIO: Fix concurrency issue").

Fixes: 0a0c3b5a24 ("Add new uio device for dynamic memory allocation")
Signed-off-by: Rafael Mendonca <rafaelmendsr@gmail.com>
Link: https://lore.kernel.org/r/20220930224100.816175-3-rafaelmendsr@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

...

This commit is contained in:

Rafael Mendonca 2022-09-30 19:40:58 -03:00 • committed by Greg Kroah-Hartman

parent 9de255c461

commit 118b918018

1 changed files with 4 additions and 1 deletions

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drivers/uio/uio_dmem_genirq.c

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