spmi: pmic-arb: check apid against limits before calling irq handler

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>
Link: https://lore.kernel.org/r/1655004286-11493-5-git-send-email-quic_fenglinw@quicinc.com
Signed-off-by: Stephen Boyd <sboyd@kernel.org>
Link: https://lore.kernel.org/r/20220930005019.2663064-6-sboyd@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/spmi/spmi-pmic-arb.c b/drivers/spmi/spmi-pmic-arb.c
index 2bc3b88..e19eaec 100644 (file)
--- a/drivers/spmi/spmi-pmic-arb.c
+++ b/drivers/spmi/spmi-pmic-arb.c
@@ -625,21 +625,26 @@ static void pmic_arb_chained_irq(struct irq_desc *desc)
        struct spmi_pmic_arb *pmic_arb = irq_desc_get_handler_data(desc);
        const struct pmic_arb_ver_ops *ver_ops = pmic_arb->ver_ops;
        struct irq_chip *chip = irq_desc_get_chip(desc);
-       int first = pmic_arb->min_apid >> 5;
-       int last = pmic_arb->max_apid >> 5;
+       int first = pmic_arb->min_apid;
+       int last = pmic_arb->max_apid;
        u8 ee = pmic_arb->ee;
        u32 status, enable, handled = 0;
        int i, id, apid;
 
        chained_irq_enter(chip, desc);
 
-       for (i = first; i <= last; ++i) {
+       for (i = first >> 5; i <= last >> 5; ++i) {
                status = readl_relaxed(
                                ver_ops->owner_acc_status(pmic_arb, ee, i));
                while (status) {
                        id = ffs(status) - 1;
                        status &= ~BIT(id);
                        apid = id + i * 32;
+                       if (apid < first || apid > last) {
+                               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)