From: Jean Delvare <khali@xxxxxxxxxxxx>
Subject: cx88: Prevent general protection fault on rmmod
When unloading the cx8800 driver I sometimes get a general protection
fault. Analysis revealed a race in cx88_ir_stop(). It can be solved by
using a delayed work instead of a timer for infrared input polling.
This fixes kernel.org bug #12802.
Signed-off-by: Jean Delvare <khali@xxxxxxxxxxxx>
---
linux/drivers/media/video/cx88/cx88-input.c | 25 ++++++++++++++++++++-----
1 file changed, 20 insertions(+), 5 deletions(-)
--- v4l-dvb.orig/linux/drivers/media/video/cx88/cx88-input.c 2009-03-04 09:52:20.000000000 +0100
+++ v4l-dvb/linux/drivers/media/video/cx88/cx88-input.c 2009-03-04 19:03:17.000000000 +0100
@@ -49,8 +49,12 @@ struct cx88_IR {
/* poll external decoder */
int polling;
+#if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,20)
struct work_struct work;
struct timer_list timer;
+#else
+ struct delayed_work work;
+#endif
u32 gpio_addr;
u32 last_gpio;
u32 mask_keycode;
@@ -144,6 +148,7 @@ static void cx88_ir_handle_key(struct cx
}
}
+#if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,20)
static void ir_timer(unsigned long data)
{
struct cx88_IR *ir = (struct cx88_IR *)data;
@@ -151,7 +156,6 @@ static void ir_timer(unsigned long data)
schedule_work(&ir->work);
}
-#if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,20)
static void cx88_ir_work(void *data)
#else
static void cx88_ir_work(struct work_struct *work)
@@ -160,23 +164,30 @@ static void cx88_ir_work(struct work_str
#if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,20)
struct cx88_IR *ir = data;
#else
- struct cx88_IR *ir = container_of(work, struct cx88_IR, work);
+ struct delayed_work *dwork = container_of(work, struct delayed_work,
+ work);
+ struct cx88_IR *ir = container_of(dwork, struct cx88_IR, work);
#endif
cx88_ir_handle_key(ir);
+#if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,20)
mod_timer(&ir->timer, jiffies + msecs_to_jiffies(ir->polling));
+#else
+ schedule_delayed_work(dwork, msecs_to_jiffies(ir->polling));
+#endif
}
void cx88_ir_start(struct cx88_core *core, struct cx88_IR *ir)
{
if (ir->polling) {
- setup_timer(&ir->timer, ir_timer, (unsigned long)ir);
#if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,20)
+ setup_timer(&ir->timer, ir_timer, (unsigned long)ir);
INIT_WORK(&ir->work, cx88_ir_work, ir);
+ schedule_work(&ir->work);
#else
- INIT_WORK(&ir->work, cx88_ir_work);
+ INIT_DELAYED_WORK(&ir->work, cx88_ir_work);
+ schedule_delayed_work(&ir->work, msecs_to_jiffies(ir->polling));
#endif
- schedule_work(&ir->work);
}
if (ir->sampling) {
core->pci_irqmask |= PCI_INT_IR_SMPINT;
@@ -193,8 +204,12 @@ void cx88_ir_stop(struct cx88_core *core
}
if (ir->polling) {
+#if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,20)
del_timer_sync(&ir->timer);
flush_scheduled_work();
+#else
+ cancel_delayed_work_sync(&ir->work);
+#endif
}
}
--
Jean Delvare
--
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