kib 2007-07-04 06:56:58 UTC
FreeBSD src repository
sys/kern kern_conf.c subr_unit.c
Since cdev mutex is after system map mutex in global lock order, free()
shall not be called while holding cdev mutex. devfs_inos unrhdr has cdev as
mutex, thus creating this LOR situation.
Postpone calling free() in kern/subr_unit.c:alloc_unr() and nested functions
until the unrhdr mutex is dropped. Save the freed items on the ppfree list
instead, and provide the clean_unrhdrl() and clean_unrhdr() functions to
clean the list.
Call clean_unrhdrl() after devfs_create() calls immediately before
dropping cdev mutex. devfs_create() is the only user of the alloc_unrl()
in the tree.
Reviewed by: phk
Tested by: Peter Holm
Approved by: re (kensmith)
Revision Changes Path
1.207 +2 -0 src/sys/kern/kern_conf.c
1.9 +34 -1 src/sys/kern/subr_unit.c
1.260 +2 -0 src/sys/sys/systm.h