[PATCH] fix memory leak in rocketport rp_do_receive

Fix memory leak caused by incorrect use of tty buffer facility.  tty
buffers are allocated but never processed by call to tty_flip_buffer_push
so they accumulate on the full buffer list.  Current code uses the buffers
as a temporary storage for data before passing it directly to the line
discipline.

Signed-off-by: Paul Fulghum <paulkf@microgate.com>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

1 files changed, 23 insertions, 39 deletions

diff --git a/drivers/char/rocket.c b/drivers/char/rocket.c
index 7edc6a4dbdc4..0708c5164c83 100644
--- a/drivers/char/rocket.c
+++ b/drivers/char/rocket.c
@@ -324,35 +324,15 @@ static void rp_do_receive(struct r_port *info,
                           CHANNEL_t * cp, unsigned int ChanStatus)
 {
         unsigned int CharNStat;
-        int ToRecv, wRecv, space = 0, count;
-        unsigned char *cbuf, *chead;
-        char *fbuf, *fhead;
-        struct tty_ldisc *ld;
-
-        ld = tty_ldisc_ref(tty);
+        int ToRecv, wRecv, space;
+        unsigned char *cbuf;
 
         ToRecv = sGetRxCnt(cp);
-        space = tty->receive_room;
-        if (space > 2 * TTY_FLIPBUF_SIZE)
-                space = 2 * TTY_FLIPBUF_SIZE;
-        count = 0;
 #ifdef ROCKET_DEBUG_INTR
-        printk(KERN_INFO "rp_do_receive(%d, %d)...", ToRecv, space);
+        printk(KERN_INFO "rp_do_receive(%d)...", ToRecv);
 #endif
-
-        /*
-         * determine how many we can actually read in.  If we can't
-         * read any in then we have a software overrun condition.
-         */
-        if (ToRecv > space)
-                ToRecv = space;
-
-        ToRecv = tty_prepare_flip_string_flags(tty, &chead, &fhead, ToRecv);
-        if (ToRecv <= 0)
-                goto done;
-
-        cbuf = chead;
-        fbuf = fhead;
+        if (ToRecv == 0)
+                return;
 
         /*
          * if status indicates there are errored characters in the
@@ -380,6 +360,8 @@ static void rp_do_receive(struct r_port *info,
                        info->read_status_mask);
 #endif
                 while (ToRecv) {
+                        char flag;
+
                         CharNStat = sInW(sGetTxRxDataIO(cp));
 #ifdef ROCKET_DEBUG_RECEIVE
                         printk(KERN_INFO "%x...", CharNStat);
@@ -392,17 +374,16 @@ static void rp_do_receive(struct r_port *info,
                         }
                         CharNStat &= info->read_status_mask;
                         if (CharNStat & STMBREAKH)
-                                *fbuf++ = TTY_BREAK;
+                                flag = TTY_BREAK;
                         else if (CharNStat & STMPARITYH)
-                                *fbuf++ = TTY_PARITY;
+                                flag = TTY_PARITY;
                         else if (CharNStat & STMFRAMEH)
-                                *fbuf++ = TTY_FRAME;
+                                flag = TTY_FRAME;
                         else if (CharNStat & STMRCVROVRH)
-                                *fbuf++ = TTY_OVERRUN;
+                                flag = TTY_OVERRUN;
                         else
-                                *fbuf++ = TTY_NORMAL;
-                        *cbuf++ = CharNStat & 0xff;
-                        count++;
+                                flag = TTY_NORMAL;
+                        tty_insert_flip_char(tty, CharNStat & 0xff, flag);
                         ToRecv--;
                 }
 
@@ -422,20 +403,23 @@ static void rp_do_receive(struct r_port *info,
                  * characters at time by doing repeated word IO
                  * transfer.
                  */
+                space = tty_prepare_flip_string(tty, &cbuf, ToRecv);
+                if (space < ToRecv) {
+#ifdef ROCKET_DEBUG_RECEIVE
+                        printk(KERN_INFO "rp_do_receive:insufficient space ToRecv=%d space=%d\n", ToRecv, space);
+#endif
+                        if (space <= 0)
+                                return;
+                        ToRecv = space;
+                }
                 wRecv = ToRecv >> 1;
                 if (wRecv)
                         sInStrW(sGetTxRxDataIO(cp), (unsigned short *) cbuf, wRecv);
                 if (ToRecv & 1)
                         cbuf[ToRecv - 1] = sInB(sGetTxRxDataIO(cp));
-                memset(fbuf, TTY_NORMAL, ToRecv);
-                cbuf += ToRecv;
-                fbuf += ToRecv;
-                count += ToRecv;
         }
         /*  Push the data up to the tty layer */
-        ld->receive_buf(tty, chead, fhead, count);
-done:
-        tty_ldisc_deref(ld);
+        tty_flip_buffer_push(tty);
 }
 
 /*