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ieee1394: nodemgr: fix rwsem recursion

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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>
This commit is contained in:
Stefan Richter 2006-09-06 19:04:00 +02:00
parent b809289df0
commit 9b51601086
1 changed files with 5 additions and 4 deletions
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9
drivers/ieee1394/nodemgr.c
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@ -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;