[PATCH] s390: console driver.

From: Martin Schwidefsky <schwidefsky@de.ibm.com>

Console driver fixes:
 - Fix ^n at end-of-line check in 3215 and sclp driver.
 - Fix copy_from_user/might_sleep/spinlock problem in sclp.

diff --git a/drivers/s390/char/con3215.c b/drivers/s390/char/con3215.c
index 29bb9bde62d27e793b30c10f5d8c501274b46a2d..0e724c8133ff9a52b84381d37b1caae51f0fa17b 100644 (file)
--- a/drivers/s390/char/con3215.c
+++ b/drivers/s390/char/con3215.c
@@ -454,7 +454,7 @@ raw3215_irq(struct ccw_device *cdev, unsigned long intparm, struct irb *irb)
                                memcpy(tty->flip.char_buf_ptr,
                                       raw->inbuf, count);
                                if (count < 2 ||
-                                   (strncmp(raw->inbuf+count-2, "^n", 2) ||
+                                   (strncmp(raw->inbuf+count-2, "^n", 2) &&
                                    strncmp(raw->inbuf+count-2, "\252n", 2)) ) {
                                        /* don't add the auto \n */
                                        tty->flip.char_buf_ptr[count] = '\n';

diff --git a/drivers/s390/char/sclp_tty.c b/drivers/s390/char/sclp_tty.c
index d9c5911bf4f92a496f4bbe23231f4ca2f20a36a4..1035707f860cd152cb7570aad1a2fc427ec24087 100644 (file)
--- a/drivers/s390/char/sclp_tty.c
+++ b/drivers/s390/char/sclp_tty.c
@@ -529,8 +529,8 @@ sclp_tty_input(unsigned char* buf, unsigned int count)
                /* send (normal) input to line discipline */
                memcpy(sclp_tty->flip.char_buf_ptr, buf, count);
                if (count < 2 ||
-                   strncmp ((const char *) buf + count - 2, "^n", 2) ||
-                   strncmp ((const char *) buf + count - 2, "\0252n", 2)) {
+                   (strncmp ((const char *) buf + count - 2, "^n", 2) &&
+                    strncmp ((const char *) buf + count - 2, "\0252n", 2))) {
                        sclp_tty->flip.char_buf_ptr[count] = '\n';
                        count++;
                } else
@@ -636,7 +636,7 @@ find_gds_vector(struct gds_vector *start, struct gds_vector *end, u16 id)
 {
        struct gds_vector *vec;
 
-       for (vec = start; vec < end; (void *) vec += vec->length)
+       for (vec = start; vec < end; vec = (void *) vec + vec->length)
                if (vec->gds_id == id)
                        return vec;
        return NULL;
@@ -648,7 +648,8 @@ find_gds_subvector(struct gds_subvector *start,
 {
        struct gds_subvector *subvec;
 
-       for (subvec = start; subvec < end; (void *) subvec += subvec->length)
+       for (subvec = start; subvec < end;
+            subvec = (void *) subvec + subvec->length)
                if (subvec->key == key)
                        return subvec;
        return NULL;
@@ -667,7 +668,7 @@ sclp_eval_selfdeftextmsg(struct gds_subvector *start,
                        break;
                sclp_get_input((unsigned char *)(subvec + 1),
                               (unsigned char *) subvec + subvec->length);
-               (void *) subvec += subvec->length;
+               subvec = (void *) subvec + subvec->length;
        }
 }
 
@@ -685,7 +686,7 @@ sclp_eval_textcmd(struct gds_subvector *start,
                        break;
                sclp_eval_selfdeftextmsg((struct gds_subvector *)(subvec + 1),
                                         (void *)subvec + subvec->length);
-               (void *) subvec += subvec->length;
+               subvec = (void *) subvec + subvec->length;
        }
 }
 
@@ -701,7 +702,7 @@ sclp_eval_cpmsu(struct gds_vector *start, struct gds_vector *end)
                        break;
                sclp_eval_textcmd((struct gds_subvector *)(vec + 1),
                                  (void *) vec + vec->length);
-               (void *) vec += vec->length;
+               vec = (void *) vec + vec->length;
        }
 }
 

diff --git a/drivers/s390/char/sclp_vt220.c b/drivers/s390/char/sclp_vt220.c
index 0521e254ead8e76946c579e15510126ac60f6018..32d4397263e0578f892927f6c23cca9d1ebda334 100644 (file)
--- a/drivers/s390/char/sclp_vt220.c
+++ b/drivers/s390/char/sclp_vt220.c
@@ -32,9 +32,10 @@
 #define SCLP_VT220_MAJOR               TTY_MAJOR
 #define SCLP_VT220_MINOR               65
 #define SCLP_VT220_DRIVER_NAME         "sclp_vt220"
-#define SCLP_VT220_DEVICE_NAME         "sclp_vt"
+#define SCLP_VT220_DEVICE_NAME         "ttysclp"
 #define SCLP_VT220_CONSOLE_NAME                "ttyS"
 #define SCLP_VT220_CONSOLE_INDEX       1       /* console=ttyS1 */
+#define SCLP_VT220_BUF_SIZE            80
 
 /* Representation of a single write request */
 struct sclp_vt220_request {
@@ -336,12 +337,11 @@ sclp_vt220_chars_stored(struct sclp_vt220_request *request)
 
 /*
  * Add msg to buffer associated with request. Return the number of characters
- * added or -EFAULT on error.
+ * added.
  */
 static int
 sclp_vt220_add_msg(struct sclp_vt220_request *request,
-                  const unsigned char *msg, int count, int from_user,
-                  int convertlf)
+                  const unsigned char *msg, int count, int convertlf)
 {
        struct sclp_vt220_sccb *sccb;
        void *buffer;
@@ -363,11 +363,7 @@ sclp_vt220_add_msg(struct sclp_vt220_request *request,
                     (from < count) && (to < sclp_vt220_space_left(request));
                     from++) {
                        /* Retrieve character */
-                       if (from_user) {
-                               if (get_user(c, msg + from) != 0)
-                                       return -EFAULT;
-                       } else
-                               c = msg[from];
+                       c = msg[from];
                        /* Perform conversion */
                        if (c == 0x0a) {
                                if (to + 1 < sclp_vt220_space_left(request)) {
@@ -383,12 +379,7 @@ sclp_vt220_add_msg(struct sclp_vt220_request *request,
                sccb->evbuf.length += to;
                return from;
        } else {
-               if (from_user) {
-                       if (copy_from_user(buffer, (void *) msg, count) != 0)
-                               return -EFAULT;
-               }
-               else
-                       memcpy(buffer, (const void *) msg, count);
+               memcpy(buffer, (const void *) msg, count);
                sccb->header.length += count;
                sccb->evbuf.length += count;
                return count;
@@ -408,7 +399,7 @@ sclp_vt220_timeout(unsigned long data)
 
 /* 
  * Internal implementation of the write function. Write COUNT bytes of data
- * from memory at BUF which may reside in user space (specified by FROM_USER)
+ * from memory at BUF
  * to the SCLP interface. In case that the data does not fit into the current
  * write buffer, emit the current one and allocate a new one. If there are no
  * more empty buffers available, wait until one gets emptied. If DO_SCHEDULE
@@ -419,8 +410,8 @@ sclp_vt220_timeout(unsigned long data)
  * of bytes written.
  */
 static int
-__sclp_vt220_write(int from_user, const unsigned char *buf, int count,
-                  int do_schedule, int convertlf)
+__sclp_vt220_write(const unsigned char *buf, int count, int do_schedule,
+                  int convertlf)
 {
        unsigned long flags;
        void *page;
@@ -451,10 +442,9 @@ __sclp_vt220_write(int from_user, const unsigned char *buf, int count,
                }
                /* Try to write the string to the current request buffer */
                written = sclp_vt220_add_msg(sclp_vt220_current_request,
-                               buf, count, from_user, convertlf);
-               if (written > 0)
-                       overall_written += written;
-               if (written == -EFAULT || written == count)
+                                            buf, count, convertlf);
+               overall_written += written;
+               if (written == count)
                        break;
                /*
                 * Not all characters could be written to the current
@@ -489,7 +479,29 @@ static int
 sclp_vt220_write(struct tty_struct *tty, int from_user,
                 const unsigned char *buf, int count)
 {
-       return __sclp_vt220_write(from_user, buf, count, 1, 0);
+       int length;
+       int ret;
+
+       if (!from_user)
+               return __sclp_vt220_write(buf, count, 1, 0);
+       /* Use intermediate buffer to prevent calling copy_from_user() while
+        * holding a lock. */
+       ret = 0;
+       while (count > 0) {
+               length = count < SCLP_VT220_BUF_SIZE ?
+                        count : SCLP_VT220_BUF_SIZE;
+               length -= copy_from_user(tty->driver_data, buf, length);
+               if (length == 0) {
+                       if (!ret)
+                               return -EFAULT;
+                       break;
+               }
+               length = __sclp_vt220_write(tty->driver_data, length, 1, 0);
+               buf += length;
+               count -= length;
+               ret += length;
+       }
+       return ret;
 }
 
 #define SCLP_VT220_SESSION_ENDED       0x01
@@ -541,9 +553,13 @@ sclp_vt220_receiver_fn(struct evbuf_header *evbuf)
 static int
 sclp_vt220_open(struct tty_struct *tty, struct file *filp)
 {
-       sclp_vt220_tty = tty;
-       tty->driver_data = NULL;
-       tty->low_latency = 0;
+       if (tty->count == 1) {
+               sclp_vt220_tty = tty;
+               tty->driver_data = kmalloc(SCLP_VT220_BUF_SIZE, GFP_KERNEL);
+               if (tty->driver_data == NULL)
+                       return -ENOMEM;
+               tty->low_latency = 0;
+       }
        return 0;
 }
 
@@ -553,9 +569,11 @@ sclp_vt220_open(struct tty_struct *tty, struct file *filp)
 static void
 sclp_vt220_close(struct tty_struct *tty, struct file *filp)
 {
-       if (tty->count > 1)
-               return;
-       sclp_vt220_tty = NULL;
+       if (tty->count == 1) {
+               sclp_vt220_tty = NULL;
+               kfree(tty->driver_data);
+               tty->driver_data = NULL;
+       }
 }
 
 /*
@@ -571,7 +589,7 @@ sclp_vt220_close(struct tty_struct *tty, struct file *filp)
 static void
 sclp_vt220_put_char(struct tty_struct *tty, unsigned char ch)
 {
-       __sclp_vt220_write(0, &ch, 1, 0, 0);
+       __sclp_vt220_write(&ch, 1, 0, 0);
 }
 
 /*
@@ -765,7 +783,7 @@ module_init(sclp_vt220_tty_init);
 static void
 sclp_vt220_con_write(struct console *con, const char *buf, unsigned int count)
 {
-       __sclp_vt220_write(0, (const unsigned char *) buf, count, 1, 1);
+       __sclp_vt220_write((const unsigned char *) buf, count, 1, 1);
 }
 
 static struct tty_driver *