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| author | Alexander Sverdlin <[email protected]> | 2025-03-31 16:36:40 +0000 |
|---|---|---|
| committer | William Breathitt Gray <[email protected]> | 2025-05-02 23:45:11 +0000 |
| commit | 7351312632e831e51383f48957d47712fae791ef (patch) | |
| tree | c3b4418c12591b387d792e645c87a6d3bdbf65d8 /drivers/fpga/tests/fpga-mgr-test.c | |
| parent | Linux 6.15-rc4 (diff) | |
| download | kernel-7351312632e831e51383f48957d47712fae791ef.tar.gz kernel-7351312632e831e51383f48957d47712fae791ef.zip | |
counter: interrupt-cnt: Protect enable/disable OPs with mutex
Enable/disable seems to be racy on SMP, consider the following scenario:
CPU0 CPU1
interrupt_cnt_enable_write(true)
{
if (priv->enabled == enable)
return 0;
if (enable) {
priv->enabled = true;
interrupt_cnt_enable_write(false)
{
if (priv->enabled == enable)
return 0;
if (enable) {
priv->enabled = true;
enable_irq(priv->irq);
} else {
disable_irq(priv->irq)
priv->enabled = false;
}
enable_irq(priv->irq);
} else {
disable_irq(priv->irq);
priv->enabled = false;
}
The above would result in priv->enabled == false, but IRQ left enabled.
Protect both write (above race) and read (to propagate the value on SMP)
callbacks with a mutex.
Signed-off-by: Alexander Sverdlin <[email protected]>
Fixes: a55ebd47f21f ("counter: add IRQ or GPIO based counter")
Acked-by: Oleksij Rempel <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: William Breathitt Gray <[email protected]>
Diffstat (limited to 'drivers/fpga/tests/fpga-mgr-test.c')
0 files changed, 0 insertions, 0 deletions