diff options
| author | Alexander Sverdlin <alexander.sverdlin@siemens.com> | 2025-03-31 18:36:40 +0200 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2025-06-19 15:40:31 +0200 |
| commit | 798d78a2cd73b52850e77ab668a5d3dc64ba040b (patch) | |
| tree | 6ed96eb3bff0a3302064eece8bd8d2793e357b5b /drivers/fpga/tests | |
| parent | f4d006a65aa5a8c9952bc0e2a579981712947445 (diff) | |
counter: interrupt-cnt: Protect enable/disable OPs with mutex
[ Upstream commit 7351312632e831e51383f48957d47712fae791ef ]
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 <alexander.sverdlin@siemens.com>
Fixes: a55ebd47f21f ("counter: add IRQ or GPIO based counter")
Acked-by: Oleksij Rempel <o.rempel@pengutronix.de>
Link: https://lore.kernel.org/r/20250331163642.2382651-1-alexander.sverdlin@siemens.com
Signed-off-by: William Breathitt Gray <wbg@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Diffstat (limited to 'drivers/fpga/tests')
0 files changed, 0 insertions, 0 deletions