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authorPeter Oberparleiter <peter.oberparleiter@de.ibm.com>2006-02-11 17:55:59 -0800
committerLinus Torvalds <torvalds@g5.osdl.org>2006-02-11 21:41:12 -0800
commit25fab9ebac445d57b656f5faabac5a195bed2f82 (patch)
tree1cb23fbe97c2fcabe020a611a8a89e9c91e804f0 /drivers/s390/char/sclp.c
parente6f3601a7275216c48c2635f46b388d970901bb9 (diff)
downloadlinux-25fab9ebac445d57b656f5faabac5a195bed2f82.tar.bz2
[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 <peter.oberparleiter@de.ibm.com> Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Diffstat (limited to 'drivers/s390/char/sclp.c')
-rw-r--r--drivers/s390/char/sclp.c13
1 files changed, 5 insertions, 8 deletions
diff --git a/drivers/s390/char/sclp.c b/drivers/s390/char/sclp.c
index ceb0e474fde4..4138564402b8 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;