| commit | c6367d1808732ae3e093c4e2023fb50d8adbcce5 | |
| author | Evan Green <evgreen@chromium.org> | |
| Tue, 29 Sep 2020 20:30:57 +0000 (29 13:30 -0700) | ||
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | |
| Tue, 29 Dec 2020 12:45:07 +0000 (29 13:45 +0100) | ||
| tree | 63975fc3b862369649f0aa8930c052cb12785f3a | treesnapshot (tar.gz zip) |
| parent | 7ce82e5dcc6f51478fa2ee53cf0853d243fe403b | commitdiff |
soc: qcom: smp2p: Safely acquire spinlock without IRQs
commit fc3e62e25c3896855b7c3d72df19ca6be3459c9f upstream.
smp2p_update_bits() should disable interrupts when it acquires its
spinlock. This is important because without the _irqsave, a priority
inversion can occur.
This function is called both with interrupts enabled in
qcom_q6v5_request_stop(), and with interrupts disabled in
ipa_smp2p_panic_notifier(). IRQ handling of spinlocks should be
consistent to avoid the panic notifier deadlocking because it's
sitting on the thread that's already got the lock via _request_stop().
Found via lockdep.
Cc: stable@vger.kernel.org
Fixes: 50e99641413e7 ("soc: qcom: smp2p: Qualcomm Shared Memory Point to Point")
Reviewed-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Reviewed-by: Stephen Boyd <swboyd@chromium.org>
Signed-off-by: Evan Green <evgreen@chromium.org>
Link: https://lore.kernel.org/r/20200929133040.RESEND.1.Ideabf6dcdfc577cf39ce3d95b0e4aa1ac8b38f0c@changeid
Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit fc3e62e25c3896855b7c3d72df19ca6be3459c9f upstream.
smp2p_update_bits() should disable interrupts when it acquires its
spinlock. This is important because without the _irqsave, a priority
inversion can occur.
This function is called both with interrupts enabled in
qcom_q6v5_request_stop(), and with interrupts disabled in
ipa_smp2p_panic_notifier(). IRQ handling of spinlocks should be
consistent to avoid the panic notifier deadlocking because it's
sitting on the thread that's already got the lock via _request_stop().
Found via lockdep.
Cc: stable@vger.kernel.org
Fixes: 50e99641413e7 ("soc: qcom: smp2p: Qualcomm Shared Memory Point to Point")
Reviewed-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Reviewed-by: Stephen Boyd <swboyd@chromium.org>
Signed-off-by: Evan Green <evgreen@chromium.org>
Link: https://lore.kernel.org/r/20200929133040.RESEND.1.Ideabf6dcdfc577cf39ce3d95b0e4aa1ac8b38f0c@changeid
Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| drivers/soc/qcom/smp2p.c | diffblobblamehistory |