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From:   Fenglin Wu <quic_fenglinw@quicinc.com>
To:     <linux-arm-msm@vger.kernel.org>, <linux-kernel@vger.kernel.org>,
        <sboyd@kernel.org>
CC:     <collinsd@codeaurora.org>, <subbaram@codeaurora.org>,
        <quic_fenglinw@quicinc.com>
Subject: [PATCH V1 3/9] spmi: pmic-arb: check apid against limits before calling irq handler
Date:   Thu, 29 Jul 2021 09:12:41 +0800
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From: David Collins <collinsd@codeaurora.org>

Check that the apid for an SPMI interrupt falls between the
min_apid and max_apid that can be handled by the APPS processor
before invoking the per-apid interrupt handler:
periph_interrupt().

This avoids an access violation in rare cases where the status
bit is set for an interrupt that is not owned by the APPS
processor.

Signed-off-by: David Collins <collinsd@codeaurora.org>
Signed-off-by: Fenglin Wu <quic_fenglinw@quicinc.com>
---
 drivers/spmi/spmi-pmic-arb.c | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/drivers/spmi/spmi-pmic-arb.c b/drivers/spmi/spmi-pmic-arb.c
index 4d7ad004..c4adc06 100644
--- a/drivers/spmi/spmi-pmic-arb.c
+++ b/drivers/spmi/spmi-pmic-arb.c
@@ -535,6 +535,12 @@ static void pmic_arb_chained_irq(struct irq_desc *desc)
 			id = ffs(status) - 1;
 			status &= ~BIT(id);
 			apid = id + i * 32;
+			if (apid < pmic_arb->min_apid
+			    || apid > pmic_arb->max_apid) {
+				WARN_ONCE(true, "spurious spmi irq received for apid=%d\n",
+					apid);
+				continue;
+			}
 			enable = readl_relaxed(
 					ver_ops->acc_enable(pmic_arb, apid));
 			if (enable & SPMI_PIC_ACC_ENABLE_BIT)
-- 
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