From 25fab9ebac445d57b656f5faabac5a195bed2f82 Mon Sep 17 00:00:00 2001 From: Peter Oberparleiter Date: Sat, 11 Feb 2006 17:55:59 -0800 Subject: [PATCH] s390: fix sclp memory corruption in tty pages list When the sclp interface takes very long to serve a request, the sclp core driver will report a failed request to the sclp tty driver even though the request is still being processed by the sclp interface. Eventually the sclp interface completes the request and updates some fields in the request buffer which leads to a corrupted tty pages list. The next time function sclp_tty_write_room is called, the corrupted list will be traversed, resulting in an oops. To avoid this remove the busy retry limit and increase retry intervals. Signed-off-by: Peter Oberparleiter Signed-off-by: Heiko Carstens Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- drivers/s390/char/sclp.c | 13 +++++-------- 1 file changed, 5 insertions(+), 8 deletions(-) diff --git a/drivers/s390/char/sclp.c b/drivers/s390/char/sclp.c index ceb0e474fde..4138564402b 100644 --- a/drivers/s390/char/sclp.c +++ b/drivers/s390/char/sclp.c @@ -85,11 +85,10 @@ static volatile enum sclp_mask_state_t { /* Maximum retry counts */ #define SCLP_INIT_RETRY 3 #define SCLP_MASK_RETRY 3 -#define SCLP_REQUEST_RETRY 3 /* Timeout intervals in seconds.*/ -#define SCLP_BUSY_INTERVAL 2 -#define SCLP_RETRY_INTERVAL 5 +#define SCLP_BUSY_INTERVAL 10 +#define SCLP_RETRY_INTERVAL 15 static void sclp_process_queue(void); static int sclp_init_mask(int calculate); @@ -153,11 +152,9 @@ __sclp_start_request(struct sclp_req *req) if (sclp_running_state != sclp_running_state_idle) return 0; del_timer(&sclp_request_timer); - if (req->start_count <= SCLP_REQUEST_RETRY) { - rc = service_call(req->command, req->sccb); - req->start_count++; - } else - rc = -EIO; + rc = service_call(req->command, req->sccb); + req->start_count++; + if (rc == 0) { /* Sucessfully started request */ req->status = SCLP_REQ_RUNNING; -- cgit v1.2.3-18-g5258