From 2571cd6a8e07a13fd3ac77f5e2c5470966d6f9c9 Mon Sep 17 00:00:00 2001 From: Julia Lawall Date: Mon, 13 Oct 2008 10:31:49 +0100 Subject: [PATCH] drivers/char/hvc_console.c: adjust call to put_tty_driver The call to put_tty_driver is out of place and is applied to the wrong argument. The function enclosing the patched code calls alloc_tty_driver and stores the result in drv. Subsequently, there are two occurrences of error handling code, one making a goto to put_tty and one making a goto to stop_thread. At the point of the first one the assignment hvc_driver = drv has not yet been executed, and from inspecting the rest of the file it seems that hvc_driver would be NULL. Thus the current call to put_tty_driver is useless, and one applied to drv is needed. The goto stop_thread is in the error handling code for a call to tty_register_driver, but the error cases in tty_register_driver do not free its argument, so it should be done here. Thus, I have moved the put_tty label after the stop_thread label, so that put_tty_driver is called in both cases. The semantic match that finds this problem is as follows: (http://www.emn.fr/x-info/coccinelle/) // @r exists@ local idexpression x; expression E,f; position p1,p2,p3; identifier l; statement S; @@ x = alloc_tty_driver@p1(...) ... if (x == NULL) S ... when != E = x when != put_tty_driver(x) goto@p2 l; ... when != E = x when != f(...,x,...) when any ( return \(0\|x\); | return@p3 ...; ) @script:python@ p1 << r.p1; p2 << r.p2; p3 << r.p3; @@ print "%s: call on line %s not freed or saved before return on line %s via line %s" % (p1[0].file,p1[0].line,p3[0].line,p2[0].line) // Signed-off-by: Julia Lawall Signed-off-by: Alan Cox Signed-off-by: Linus Torvalds --- drivers/char/hvc_console.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/drivers/char/hvc_console.c b/drivers/char/hvc_console.c index fd64137b1ab..ec7aded0a2d 100644 --- a/drivers/char/hvc_console.c +++ b/drivers/char/hvc_console.c @@ -819,11 +819,11 @@ static int hvc_init(void) hvc_driver = drv; return 0; -put_tty: - put_tty_driver(hvc_driver); stop_thread: kthread_stop(hvc_task); hvc_task = NULL; +put_tty: + put_tty_driver(drv); out: return err; } -- 2.41.1