lists.openwall.net   lists  /  announce  owl-users  owl-dev  john-users  john-dev  passwdqc-users  yescrypt  popa3d-users  /  oss-security  kernel-hardening  musl  sabotage  tlsify  passwords  /  crypt-dev  xvendor  /  Bugtraq  Full-Disclosure  linux-kernel  linux-netdev  linux-ext4  linux-hardening  linux-cve-announce  PHC 
Open Source and information security mailing list archives
 
Hash Suite: Windows password security audit tool. GUI, reports in PDF.
[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Message-Id: <20190515090654.831421645@linuxfoundation.org>
Date:   Wed, 15 May 2019 12:55:45 +0200
From:   Greg Kroah-Hartman <gregkh@...uxfoundation.org>
To:     linux-kernel@...r.kernel.org
Cc:     Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
        stable@...r.kernel.org,
        Martin Schwidefsky <schwidefsky@...ibm.com>,
        Sasha Levin <sashal@...nel.org>
Subject: [PATCH 3.18 68/86] s390/3270: fix lockdep false positive on view->lock

[ Upstream commit 5712f3301a12c0c3de9cc423484496b0464f2faf ]

The spinlock in the raw3270_view structure is used by con3270, tty3270
and fs3270 in different ways. For con3270 the lock can be acquired in
irq context, for tty3270 and fs3270 the highest context is bh.

Lockdep sees the view->lock as a single class and if the 3270 driver
is used for the console the following message is generated:

WARNING: inconsistent lock state
5.1.0-rc3-05157-g5c168033979d #12 Not tainted
--------------------------------
inconsistent {IN-HARDIRQ-W} -> {HARDIRQ-ON-W} usage.
swapper/0/1 [HC0[0]:SC1[1]:HE1:SE0] takes:
(____ptrval____) (&(&view->lock)->rlock){?.-.}, at: tty3270_update+0x7c/0x330

Introduce a lockdep subclass for the view lock to distinguish bh from
irq locks.

Signed-off-by: Martin Schwidefsky <schwidefsky@...ibm.com>

Signed-off-by: Sasha Levin <sashal@...nel.org>
---
 drivers/s390/char/con3270.c | 2 +-
 drivers/s390/char/fs3270.c  | 3 ++-
 drivers/s390/char/raw3270.c | 3 ++-
 drivers/s390/char/raw3270.h | 4 +++-
 drivers/s390/char/tty3270.c | 3 ++-
 5 files changed, 10 insertions(+), 5 deletions(-)

diff --git a/drivers/s390/char/con3270.c b/drivers/s390/char/con3270.c
index 7c511add5aa7d..84b6c5080a790 100644
--- a/drivers/s390/char/con3270.c
+++ b/drivers/s390/char/con3270.c
@@ -622,7 +622,7 @@ con3270_init(void)
 		     (void (*)(unsigned long)) con3270_read_tasklet,
 		     (unsigned long) condev->read);
 
-	raw3270_add_view(&condev->view, &con3270_fn, 1);
+	raw3270_add_view(&condev->view, &con3270_fn, 1, RAW3270_VIEW_LOCK_IRQ);
 
 	INIT_LIST_HEAD(&condev->freemem);
 	for (i = 0; i < CON3270_STRING_PAGES; i++) {
diff --git a/drivers/s390/char/fs3270.c b/drivers/s390/char/fs3270.c
index 71e9747380149..f0c86bcbe3161 100644
--- a/drivers/s390/char/fs3270.c
+++ b/drivers/s390/char/fs3270.c
@@ -463,7 +463,8 @@ fs3270_open(struct inode *inode, struct file *filp)
 
 	init_waitqueue_head(&fp->wait);
 	fp->fs_pid = get_pid(task_pid(current));
-	rc = raw3270_add_view(&fp->view, &fs3270_fn, minor);
+	rc = raw3270_add_view(&fp->view, &fs3270_fn, minor,
+			      RAW3270_VIEW_LOCK_BH);
 	if (rc) {
 		fs3270_free_view(&fp->view);
 		goto out;
diff --git a/drivers/s390/char/raw3270.c b/drivers/s390/char/raw3270.c
index 220acb4cbee52..9c350e6d75bf7 100644
--- a/drivers/s390/char/raw3270.c
+++ b/drivers/s390/char/raw3270.c
@@ -956,7 +956,7 @@ raw3270_deactivate_view(struct raw3270_view *view)
  * Add view to device with minor "minor".
  */
 int
-raw3270_add_view(struct raw3270_view *view, struct raw3270_fn *fn, int minor)
+raw3270_add_view(struct raw3270_view *view, struct raw3270_fn *fn, int minor, int subclass)
 {
 	unsigned long flags;
 	struct raw3270 *rp;
@@ -978,6 +978,7 @@ raw3270_add_view(struct raw3270_view *view, struct raw3270_fn *fn, int minor)
 		view->cols = rp->cols;
 		view->ascebc = rp->ascebc;
 		spin_lock_init(&view->lock);
+		lockdep_set_subclass(&view->lock, subclass);
 		list_add(&view->list, &rp->view_list);
 		rc = 0;
 		spin_unlock_irqrestore(get_ccwdev_lock(rp->cdev), flags);
diff --git a/drivers/s390/char/raw3270.h b/drivers/s390/char/raw3270.h
index e1e41c2861fbb..5ae54317857a0 100644
--- a/drivers/s390/char/raw3270.h
+++ b/drivers/s390/char/raw3270.h
@@ -155,6 +155,8 @@ struct raw3270_fn {
 struct raw3270_view {
 	struct list_head list;
 	spinlock_t lock;
+#define RAW3270_VIEW_LOCK_IRQ	0
+#define RAW3270_VIEW_LOCK_BH	1
 	atomic_t ref_count;
 	struct raw3270 *dev;
 	struct raw3270_fn *fn;
@@ -163,7 +165,7 @@ struct raw3270_view {
 	unsigned char *ascebc;		/* ascii -> ebcdic table */
 };
 
-int raw3270_add_view(struct raw3270_view *, struct raw3270_fn *, int);
+int raw3270_add_view(struct raw3270_view *, struct raw3270_fn *, int, int);
 int raw3270_activate_view(struct raw3270_view *);
 void raw3270_del_view(struct raw3270_view *);
 void raw3270_deactivate_view(struct raw3270_view *);
diff --git a/drivers/s390/char/tty3270.c b/drivers/s390/char/tty3270.c
index e96fc7fd94984..ab95d24b991b4 100644
--- a/drivers/s390/char/tty3270.c
+++ b/drivers/s390/char/tty3270.c
@@ -937,7 +937,8 @@ static int tty3270_install(struct tty_driver *driver, struct tty_struct *tty)
 		return PTR_ERR(tp);
 
 	rc = raw3270_add_view(&tp->view, &tty3270_fn,
-			      tty->index + RAW3270_FIRSTMINOR);
+			      tty->index + RAW3270_FIRSTMINOR,
+			      RAW3270_VIEW_LOCK_BH);
 	if (rc) {
 		tty3270_free_view(tp);
 		return rc;
-- 
2.20.1



Powered by blists - more mailing lists

Powered by Openwall GNU/*/Linux Powered by OpenVZ