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| author | Stefan Richter <stefanr@s5r6.in-berlin.de> | 2006-09-06 19:04:00 +0200 |
|---|---|---|
| committer | Stefan Richter <stefanr@s5r6.in-berlin.de> | 2006-09-17 19:38:14 +0200 |
| commit | 9b516010863195ba7db061233a3eeffe779130e8 (patch) | |
| tree | 90e2b8a96d8010d350f2a62f676aab0dc6d55a76 /drivers/ieee1394/nodemgr.c | |
| parent | ieee1394: sbp2: more help in Kconfig (diff) | |
| download | linux-9b516010863195ba7db061233a3eeffe779130e8.tar.xz linux-9b516010863195ba7db061233a3eeffe779130e8.zip | |
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.c | 9 |
1 files changed, 5 insertions, 4 deletions
diff --git a/drivers/ieee1394/nodemgr.c b/drivers/ieee1394/nodemgr.c index eabc51b23c0b..f087f7e2b691 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; |