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authorStefan Richter <stefanr@s5r6.in-berlin.de>2006-09-06 19:04:00 +0200
committerStefan Richter <stefanr@s5r6.in-berlin.de>2006-09-17 19:38:14 +0200
commit9b516010863195ba7db061233a3eeffe779130e8 (patch)
tree90e2b8a96d8010d350f2a62f676aab0dc6d55a76 /drivers/ieee1394/nodemgr.c
parentb809289df06ff9453c1b19df74ea83aba311dfc6 (diff)
ieee1394: nodemgr: fix rwsem recursion
nodemgr_update_pdrv grabbed an rw semaphore (as reader) which was already taken by its caller's caller, nodemgr_probe_ne (as reader too). Reported by Miles Lane, call path pointed out by Arjan van de Ven. FIXME: Shouldn't we rather use class->sem there, not class->subsys.rwsem? Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
Diffstat (limited to 'drivers/ieee1394/nodemgr.c')
-rw-r--r--drivers/ieee1394/nodemgr.c9
1 files changed, 5 insertions, 4 deletions
diff --git a/drivers/ieee1394/nodemgr.c b/drivers/ieee1394/nodemgr.c
index eabc51b23c0..f087f7e2b69 100644
--- a/drivers/ieee1394/nodemgr.c
+++ b/drivers/ieee1394/nodemgr.c
@@ -1316,6 +1316,7 @@ static void nodemgr_node_scan(struct host_info *hi, int generation)
}
+/* Caller needs to hold nodemgr_ud_class.subsys.rwsem as reader. */
static void nodemgr_suspend_ne(struct node_entry *ne)
{
struct class_device *cdev;
@@ -1368,15 +1369,14 @@ static void nodemgr_resume_ne(struct node_entry *ne)
}
+/* Caller needs to hold nodemgr_ud_class.subsys.rwsem as reader. */
static void nodemgr_update_pdrv(struct node_entry *ne)
{
struct unit_directory *ud;
struct hpsb_protocol_driver *pdrv;
- struct class *class = &nodemgr_ud_class;
struct class_device *cdev;
- down_read(&class->subsys.rwsem);
- list_for_each_entry(cdev, &class->children, node) {
+ list_for_each_entry(cdev, &nodemgr_ud_class.children, node) {
ud = container_of(cdev, struct unit_directory, class_dev);
if (ud->ne != ne || !ud->device.driver)
continue;
@@ -1389,7 +1389,6 @@ static void nodemgr_update_pdrv(struct node_entry *ne)
up_write(&ud->device.bus->subsys.rwsem);
}
}
- up_read(&class->subsys.rwsem);
}
@@ -1420,6 +1419,8 @@ static void nodemgr_irm_write_bc(struct node_entry *ne, int generation)
}
+/* Caller needs to hold nodemgr_ud_class.subsys.rwsem as reader because the
+ * calls to nodemgr_update_pdrv() and nodemgr_suspend_ne() here require it. */
static void nodemgr_probe_ne(struct host_info *hi, struct node_entry *ne, int generation)
{
struct device *dev;