From: Peter Hurley <peter@hurleysoftware.com>
To: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Jiri Slaby <jslaby@suse.cz>,
linux-serial@vger.kernel.org, linux-kernel@vger.kernel.org,
Peter Hurley <peter@hurleysoftware.com>
Subject: [PATCH] pty: Fix overlimit memory use
Date: Fri, 16 Jan 2015 15:22:14 -0500 [thread overview]
Message-ID: <1421439734-17335-1-git-send-email-peter@hurleysoftware.com> (raw)
The pty_space() computation is broken; the space already consumed
in the tty buffer is not accounted for.
Use tty_buffer_set_limit(), which enforces the limit automatically.
Signed-off-by: Peter Hurley <peter@hurleysoftware.com>
---
drivers/tty/pty.c | 17 +++--------------
1 file changed, 3 insertions(+), 14 deletions(-)
diff --git a/drivers/tty/pty.c b/drivers/tty/pty.c
index a9d256d..2cf2567 100644
--- a/drivers/tty/pty.c
+++ b/drivers/tty/pty.c
@@ -88,19 +88,6 @@ static void pty_unthrottle(struct tty_struct *tty)
}
/**
- * pty_space - report space left for writing
- * @to: tty we are writing into
- *
- * Limit the buffer space used by ptys to 8k.
- */
-
-static int pty_space(struct tty_struct *to)
-{
- int n = tty_buffer_space_avail(to->port);
- return min(n, 8192);
-}
-
-/**
* pty_write - write to a pty
* @tty: the tty we write from
* @buf: kernel buffer of data
@@ -141,7 +128,7 @@ static int pty_write_room(struct tty_struct *tty)
{
if (tty->stopped)
return 0;
- return pty_space(tty->link);
+ return tty_buffer_space_avail(tty->link->port);
}
/**
@@ -429,6 +416,8 @@ static int pty_common_install(struct tty_driver *driver, struct tty_struct *tty,
o_tty->link = tty;
tty_port_init(ports[0]);
tty_port_init(ports[1]);
+ tty_buffer_set_limit(ports[0], 8192);
+ tty_buffer_set_limit(ports[1], 8192);
o_tty->port = ports[0];
tty->port = ports[1];
o_tty->port->itty = o_tty;
--
2.2.2
reply other threads:[~2015-01-16 20:22 UTC|newest]
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