When working on the 8250_pci driver on PPC, the rmmod command was resulting in a crash when removing the module. The serial8250_do_pm() is called after the memory are deallocated, meaning that serial8250_set_sleep->serial_outp() will try to write to a
position that is invalid, crashing the system. The purpose of this patch is to correct that issue.
This patch was created against 2.6.38.6
Patch-created-by: Breno Leitao <leitao@xxxxxxxxxxxxxxxxxx>
Cc: Greg Kroah-Hartman <gregkh@xxxxxxx>
Cc: Breno Leitao <leitao@xxxxxxxxxxxxxxxxxx>
Cc: Scott Kilau <scottk@xxxxxxxx>
Signed-off-by: Michael Reed <mreed@xxxxxxxxxxxxxxxxxx>
---
drivers/tty/serial/8250.c | 6 +++++-
1 files changed, 5 insertions(+), 1 deletions(-)
diff --git a/drivers/tty/serial/8250.c b/drivers/tty/serial/8250.c
index b3b881b..7617cde 100644
--- a/drivers/tty/serial/8250.c
+++ b/drivers/tty/serial/8250.c
@@ -145,6 +145,8 @@ struct uart_8250_port {
unsigned char mcr_mask; /* mask of user bits */
unsigned char mcr_force; /* mask of forced bits */
unsigned char cur_iotype; /* Running I/O type */
+#define SERIAL8250_DYING 1
+ unsigned char status;
/*
* Some bits in registers are cleared on a read, so they must
@@ -2494,7 +2496,8 @@ void serial8250_do_pm(struct uart_port *port, unsigned int state,
struct uart_8250_port *p =
container_of(port, struct uart_8250_port, port);
- serial8250_set_sleep(p, state != 0);
+ if (!(p->status & SERIAL8250_DYING))
+ serial8250_set_sleep(p, state != 0);
}
EXPORT_SYMBOL(serial8250_do_pm);
@@ -2588,6 +2591,7 @@ static void serial8250_release_std_resource(struct uart_8250_port *up)
release_region(up->port.iobase, size);
break;
}
+ up->status |= SERIAL8250_DYING;
}
static int serial8250_request_rsa_resource(struct uart_8250_port *up)
--
1.7.1
--
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