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authorPeter Oberparleiter <peter.oberparleiter@de.ibm.com>2006-02-11 20:55:59 -0500
committerLinus Torvalds <torvalds@g5.osdl.org>2006-02-12 00:41:12 -0500
commit25fab9ebac445d57b656f5faabac5a195bed2f82 (patch)
tree1cb23fbe97c2fcabe020a611a8a89e9c91e804f0 /drivers/s390
parente6f3601a7275216c48c2635f46b388d970901bb9 (diff)
[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')
-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 {
85/* Maximum retry counts */ 85/* Maximum retry counts */
86#define SCLP_INIT_RETRY 3 86#define SCLP_INIT_RETRY 3
87#define SCLP_MASK_RETRY 3 87#define SCLP_MASK_RETRY 3
88#define SCLP_REQUEST_RETRY 3
89 88
90/* Timeout intervals in seconds.*/ 89/* Timeout intervals in seconds.*/
91#define SCLP_BUSY_INTERVAL 2 90#define SCLP_BUSY_INTERVAL 10
92#define SCLP_RETRY_INTERVAL 5 91#define SCLP_RETRY_INTERVAL 15
93 92
94static void sclp_process_queue(void); 93static void sclp_process_queue(void);
95static int sclp_init_mask(int calculate); 94static int sclp_init_mask(int calculate);
@@ -153,11 +152,9 @@ __sclp_start_request(struct sclp_req *req)
153 if (sclp_running_state != sclp_running_state_idle) 152 if (sclp_running_state != sclp_running_state_idle)
154 return 0; 153 return 0;
155 del_timer(&sclp_request_timer); 154 del_timer(&sclp_request_timer);
156 if (req->start_count <= SCLP_REQUEST_RETRY) { 155 rc = service_call(req->command, req->sccb);
157 rc = service_call(req->command, req->sccb); 156 req->start_count++;
158 req->start_count++; 157
159 } else
160 rc = -EIO;
161 if (rc == 0) { 158 if (rc == 0) {
162 /* Sucessfully started request */ 159 /* Sucessfully started request */
163 req->status = SCLP_REQ_RUNNING; 160 req->status = SCLP_REQ_RUNNING;