drivers/char: for hpet, add count checking, and ~0UL instead of -1

PATCH New Chen Gang 1 participant 1 message Nov 23, 2012

Subsystems (2)

Char and misc drivers Hpet: High Precision Event Timers driver

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Chen Gang

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2012-11-23 09:45 UTC #0 lore raw

PATCH 1/1 drivers/char: for hpet, add count checking, and ~0UL instead of -1

use ~0UL for unsigned long variable initialization, instead of -1.

add check for hdp->hd_nirqs within 32 (HPET_MAX_TIMERS).

    the type of irqp->interrupt_count is u8.
    the git diff not display the relative lines below.
      hdp->hd_irq[hdp->hd_nirqs] = irq;
      hdp->hd_nirqs++;
    please check source code to get more information.

Signed-off-by Chen Gang <[email protected]>

---
 drivers/char/hpet.c |    5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

drivers/char/hpet.c +4 -1

index dfd7876..fe6d4be 100644
@@ -816,7 +816,7 @@ static unsigned long __hpet_calibrate(struct hpets *hpetp)
 
 static unsigned long hpet_calibrate(struct hpets *hpetp)
 {
-	unsigned long ret = -1;
+	unsigned long ret = ~0UL;
 	unsigned long tmp;
 
 	/*

@@ -1001,6 +1001,9 @@ static acpi_status hpet_resources(struct acpi_resource *res, void *data)
 		irqp = &res->data.extended_irq;
 
 		for (i = 0; i < irqp->interrupt_count; i++) {
+			if (hdp->hd_nirqs >= HPET_MAX_TIMERS)
+				break;
+
 			irq = acpi_register_gsi(NULL, irqp->interrupts[i],
 				      irqp->triggering, irqp->polarity);
 			if (irq < 0)

Signature · 1 line

1.7.10.4