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[Qemu-devel] [PATCH v2] timer: a9gtimer: check auto-increment register v
From: |
P J P |
Subject: |
[Qemu-devel] [PATCH v2] timer: a9gtimer: check auto-increment register value |
Date: |
Wed, 28 Sep 2016 14:46:48 +0530 |
From: Prasad J Pandit <address@hidden>
ARM A9MP processor has a peripheral timer with an auto-increment
register, which holds an increment step value. A user could set
this value to zero, when auto-increment control bit is enabled.
This leads to an infinite loop in 'a9_gtimer_update' while
updating comparator value. Remove the loop incrementing the
comparator value; Add check to avoid value zero.
Reported-by: Li Qiang <address@hidden>
Signed-off-by: Prasad J Pandit <address@hidden>
---
hw/timer/a9gtimer.c | 22 ++++++++++------------
1 file changed, 10 insertions(+), 12 deletions(-)
Update per
-> https://lists.gnu.org/archive/html/qemu-devel/2016-09/msg05682.html
diff --git a/hw/timer/a9gtimer.c b/hw/timer/a9gtimer.c
index 772f85f..021ae59 100644
--- a/hw/timer/a9gtimer.c
+++ b/hw/timer/a9gtimer.c
@@ -72,7 +72,7 @@ static void a9_gtimer_update(A9GTimerState *s, bool sync)
{
A9GTimerUpdate update = a9_gtimer_get_update(s);
- int i;
+ uint32_t i, inc;
int64_t next_cdiff = 0;
for (i = 0; i < s->num_cpu; ++i) {
@@ -82,16 +82,14 @@ static void a9_gtimer_update(A9GTimerState *s, bool sync)
if ((s->control & R_CONTROL_TIMER_ENABLE) &&
(gtb->control & R_CONTROL_COMP_ENABLE)) {
/* R2p0+, where the compare function is >= */
- while (gtb->compare < update.new) {
- DB_PRINT("Compare event happened for CPU %d\n", i);
- gtb->status = 1;
- if (gtb->control & R_CONTROL_AUTO_INCREMENT) {
- DB_PRINT("Auto incrementing timer compare by %" PRId32
"\n",
- gtb->inc);
- gtb->compare += gtb->inc;
- } else {
- break;
- }
+ DB_PRINT("Compare event happened for CPU %d\n", i);
+ gtb->status = 1;
+ if (gtb->control & R_CONTROL_AUTO_INCREMENT
+ && gtb->compare < update.new) {
+ inc = ((update.new - gtb->compare - 1) / gtb->inc) * gtb->inc;
+ DB_PRINT("Auto incrementing timer compare by %"
+ PRId32 "\n", inc);
+ gtb->compare += inc;
}
cdiff = (int64_t)gtb->compare - (int64_t)update.new + 1;
if (cdiff > 0 && (cdiff < next_cdiff || !next_cdiff)) {
@@ -210,7 +208,7 @@ static void a9_gtimer_write(void *opaque, hwaddr addr,
uint64_t value,
gtb->compare = deposit64(gtb->compare, shift, 32, value);
break;
case R_AUTO_INCREMENT:
- gtb->inc = value;
+ gtb->inc = value ? value : 1;
return;
default:
return;
--
2.5.5
- [Qemu-devel] [PATCH v2] timer: a9gtimer: check auto-increment register value,
P J P <=